Surgical management of pediatric spinal aneurysmal bone cysts: patient series

BACKGROUND

Aneurysmal bone cysts (ABCs) are rare, highly vascular osteolytic bone lesions that predominantly affect pediatric populations. This report evaluates the clinicopathological data of pediatric patients with spinal ABCs. The medical records for all patients at Children's Hospital Los Angeles with biopsy-proven ABCs of the spine between 1998 and 2018 were evaluated.

OBSERVATIONS

Seventeen patients, 6 males and 11 females, were identified. The mean age at surgery was 10.4 years (range, 3.5-20 years). The most common presenting complaint was pain at the lesion site 16/17 (94%), followed by lower-extremity weakness 8/17 (47%). Resection and intralesional curettage were performed in all patients. Three (18%) of 17 patients underwent selective arterial embolization prior to resection. Spinal stability was compromised in 15 of 17 patients (88%), requiring instrumented fusion. Five (29%) of the 17 patients received additional therapy including radiation, calcitonin-methylprednisolone, or phenol. Four (23.5%) of 17 patients experienced a recurrence, and the mean time to recurrence was 15 months. The postoperative follow-up ranged from 6 to 108 months (median, 28 months). Reoperation occurred after an average of 35 months. At the recent follow-up, patients were free of disease.

LESSONS

Gross-total resection by intralesional curettage with case-dependent instrumented spinal fusion for instability remains an effective strategy for managing pediatric spinal ABCs. Long-term follow-up is necessary to detect tumor recurrence.

Minimally invasive surgical treatment of intracranial meningiomas in elderly patients (≥ 65 years): outcomes, readmissions, and tumor control

OBJECTIVE

Increased lifespan has led to more elderly patients being diagnosed with meningiomas. In this study, the authors sought to analyze and compare patients ≥ 65 years old with those < 65 years old who underwent minimally invasive surgery for meningioma. To address surgical selection criteria, the authors also assessed a cohort of patients managed without surgery.

METHODS

In a retrospective analysis, consecutive patients with meningiomas who underwent minimally invasive (endonasal, supraorbital, minipterional, transfalcine, or retromastoid) and conventional surgical treatment approaches during the period from 2008 to 2019 were dichotomized into those ≥ 65 and those < 65 years old to compare resection rates, endoscopy use, complications, and length of hospital stay (LOS). A comparator meningioma cohort of patients ≥ 65 years old who were observed without surgery during the period from 2015 to 2019 was also analyzed.

RESULTS

Of 291 patients (median age 60 years, 71.5% females, mean follow-up 36 months) undergoing meningioma resection, 118 (40.5%) were aged ≥ 65 years and underwent 126 surgeries, including 20% redo operations, as follows: age 65-69 years, 46 operations; 70-74 years, 40 operations; 75-79 years, 17 operations; and ≥ 80 years, 23 operations. During 2015-2019, of 98 patients referred for meningioma, 67 (68%) had surgery, 1 (1%) had radiosurgery, and 31 (32%) were observed. In the 11-year surgical cohort, comparing 173 patients < 65 years versus 118 patients ≥ 65 years old, there were no significant differences in tumor location, size, or outcomes. Of 126 cases of surgery in 118 elderly patients, the approach was a minimally invasive approach to skull base meningioma (SBM) in 64 cases (51%) as follows: endonasal 18, supraorbital 28, minipterional 6, and retrosigmoid 12. Endoscope-assisted surgery was performed in 59.5% of patients. A conventional approach to SBM was performed in 15 cases (12%) (endoscope-assisted 13.3%), and convexity craniotomy for non-skull base meningioma (NSBM) in 47 cases (37%) (endoscope-assisted 17%). In these three cohorts (minimally invasive SBM, conventional SBM, and NSBM), the gross-total/near-total resection rates were 59.5%, 60%, and 91.5%, respectively, and an improved or stable Karnofsky Performance Status score occurred in 88.6%, 86.7%, and 87.2% of cases, respectively. For these 118 elderly patients, the median LOS was 3 days, and major complications occurred in 10 patients (8%) as follows: stroke 4%, vision decline 3%, systemic complications 0.7%, and wound infection or death 0. Eighty-three percent of patients were discharged home, and readmissions occurred in 5 patients (4%). Meningioma recurrence occurred in 4 patients (3%) and progression in 11 (9%). Multivariate regression analysis showed no significance of American Society of Anesthesiologists physical status score, comorbidities, or age subgroups on outcomes; patients aged ≥ 80 years showed a trend of longer hospitalization.

CONCLUSIONS

This analysis suggests that elderly patients with meningiomas, when carefully selected, generally have excellent surgical outcomes and tumor control. When applied appropriately, use of minimally invasive approaches and endoscopy may be helpful in achieving maximal safe resection, reducing complications, and promoting short hospitalizations. Notably, one-third of our elderly meningioma patients referred for possible surgery from 2015 to 2019 were managed nonoperatively.

The use of autologous free vascularized fibula grafts in reconstruction of the mobile spine following tumor resection: surgical technique and outcomes

OBJECTIVE

Reconstruction of the mobile spine following total en bloc spondylectomy (TES) of one or multiple vertebral bodies in patients with malignant spinal tumors is a challenging procedure with high failure rates. A common reason for reconstructive failure is nonunion, which becomes more problematic when using local radiation therapy. Radiotherapy is an integral part of the management of primary malignant osseous tumors in the spine. Vascularized grafts may help prevent nonunion in the radiotherapy setting. The authors have utilized free vascularized fibular grafts (FVFGs) for reconstruction of the spine following TES. The purpose of this article is to describe the surgical technique for vascularized reconstruction of defects after TES. Additionally, the outcomes of consecutive cases treated with this technique are reported.

METHODS

Thirty-nine patients were treated at the authors' tertiary care institution for malignant tumors in the mobile spine using FVFG following TES between 2010 and 2018. Postoperative union, reoperations, complications, neurological outcome, and survival were reported. The median follow-up duration was 50 months (range 14-109 months).

RESULTS

The cohort consisted of 26 males (67%), and the median age was 58 years. Chordoma was the most prevalent tumor (67%), and the lumbar spine was most affected (46%). Complete union was seen in 26 patients (76%), the overall complication rate was 54%, and implant failure was the most common complication, with 13 patients (33%) affected. In 18 patients (46%), one or more reoperations were needed, and the fixation was surgically revised 15 times (42% of reoperations) in 10 patients (26%). A reconstruction below the L1 vertebra had a higher proportion of implant failure (67%; 8 of 12 patients) compared with higher resections (21%; 5 of 24 patients) (p = 0.011). Graft length, number of resected vertebrae, and docking the FVFG on the endplate or cancellous bone was not associated with union or implant failure on univariate analysis.

CONCLUSIONS

The FVFG is an effective reconstruction technique, particularly in the cervicothoracic spine. However, high implant failure rates in the lumbar spine have been seen, which occurred even in cases in which the graft completely healed. Methods to increase the weight-bearing capacity of the graft in the lumbar spine should be considered in these reconstructions. Overall, the rates of failure and revision surgery for FVFG compare with previous reports on reconstruction after TES.

Lateral lumbar interbody fusion in revision surgery for restenosis after posterior decompression

OBJECTIVE

The purpose of this study was to compare the clinical results of revision interbody fusion surgery between lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) with propensity score (PS) adjustments and to investigate the efficacy of indirect decompression with LLIF in previously decompressed segments on the basis of radiological assessment.

METHODS

A retrospective study of patients who underwent revision surgery for recurrence of neurological symptoms after posterior decompression surgery was performed. Postoperative complications and operative factors were evaluated and compared between LLIF and PLIF/TLIF. Moreover, postoperative improvement in cross-sectional areas (CSAs) in the spinal canal and intervertebral foramen was evaluated in LLIF cases.

RESULTS

A total of 56 patients (21 and 35 cases of LLIF and PLIF/TLIF, respectively) were included. In the univariate analysis, the LLIF group had significantly more endplate injuries (p = 0.03) and neurological deficits (p = 0.042), whereas the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), surgical site infections (SSIs) (p = 0.02), and estimated blood loss (EBL) (p < 0.001). After PS adjustments, the LLIF group still showed significantly more endplate injuries (p = 0.03), and the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), EBL (p < 0.001), and operating time (p = 0.04). The PLIF/TLIF group showed a trend toward a higher incidence of SSI (p = 0.10). There was no statistically significant difference regarding improvement in the Japanese Orthopaedic Association scores between the 2 surgical procedures (p = 0.77). The CSAs in the spinal canal and foramen were both significantly improved (p < 0.001).

CONCLUSIONS

LLIF is a safe, effective, and less invasive procedure with acceptable complication rates for revision surgery for previously decompressed segments. Therefore, LLIF can be an alternative to PLIF/TLIF for restenosis after posterior decompression surgery.

The effect of anterior lumbar interbody fusion staging order on perioperative complications in circumferential lumbar fusions performed within the same hospital admission

OBJECTIVE

Anterior lumbar interbody fusion (ALIF) is a powerful technique that provides wide access to the disc space and allows for large lordotic grafts. When used with posterior spinal fusion (PSF), the procedures are often staged within the same hospital admission. There are limited data on the perioperative risk profile of ALIF-first versus PSF-first circumferential fusions performed within the same hospital admission. In an effort to understand whether these procedures are associated with different perioperative complication profiles, the authors performed a retrospective review of their institutional experience in adult patients who had undergone circumferential lumbar fusions.

METHODS

The electronic medicals records of patients who had undergone ALIF and PSF on separate days within the same hospital admission at a single academic center were retrospectively analyzed. Patients carrying a diagnosis of tumor, infection, or traumatic fracture were excluded. Demographics, surgical characteristics, and perioperative complications were collected and assessed.

RESULTS

A total of 373 patients, 217 of them women (58.2%), met the inclusion criteria. The mean age of the study cohort was 60 years. Surgical indications were as follows: degenerative disease or spondylolisthesis, 171 (45.8%); adult deformity, 168 (45.0%); and pseudarthrosis, 34 (9.1%). The majority of patients underwent ALIF first (321 [86.1%]) with a mean time of 2.5 days between stages. The mean number of levels fused was 2.1 for ALIF and 6.8 for PSF. In a comparison of ALIF-first to PSF-first cases, there were no major differences in demographics or surgical characteristics. Rates of intraoperative complications including venous injury were not significantly different between the two groups. The rates of postoperative ileus (11.8% vs 5.8%, p = 0.194) and ALIF-related wound complications (9.0% vs 3.8%, p = 0.283) were slightly higher in the ALIF-first group, although the differences did not reach statistical significance. Rates of other perioperative complications were no different.

CONCLUSIONS

In patients undergoing staged circumferential fusion with ALIF and PSF, there was no statistically significant difference in the rate of perioperative complications when comparing ALIF-first to PSF-first surgeries.

Asymmetrical pedicle subtraction osteotomy for correction of concurrent sagittal-coronal imbalance in adult spinal deformity: a comparative analysis

OBJECTIVE

Rigid multiplanar thoracolumbar adult spinal deformity (ASD) cases are challenging and many require a 3-column osteotomy (3CO), specifically asymmetrical pedicle subtraction osteotomy (APSO). The outcomes and additional risks of performing APSO for the correction of concurrent sagittal-coronal deformity have yet to be adequately studied.

METHODS

The authors performed a retrospective review of all ASD patients who underwent 3CO during the period from 2006 to 2019. All cases involved either isolated sagittal deformity (patients underwent standard PSO) or concurrent sagittal-coronal deformity (coronal vertical axis [CVA] ≥ 4.0 cm; patients underwent APSO). Perioperative and 2-year follow-up outcomes were compared between patients with isolated sagittal imbalance who underwent PSO and those with concurrent sagittal-coronal imbalance who underwent APSO.

RESULTS

A total of 390 patients were included: 338 who underwent PSO and 52 who underwent APSO. The mean patient age was 64.6 years, and 65.1% of patients were female. APSO patients required significantly more fusions with upper instrumented vertebrae (UIV) in the upper thoracic spine (63.5% vs 43.3%, p = 0.007). Radiographically, APSO patients had greater deformity with more severe preoperative sagittal and coronal imbalance: sagittal vertical axis (SVA) 13.0 versus 10.7 cm (p = 0.042) and CVA 6.1 versus 1.2 cm (p < 0.001). In APSO cases, significant correction and normalization were achieved (SVA 13.0-3.1 cm, CVA 6.1-2.0 cm, lumbar lordosis [LL] 26.3°-49.4°, pelvic tilt [PT] 38.0°-20.4°, and scoliosis 25.0°-10.4°, p < 0.001). The overall perioperative complication rate was 34.9%. There were no significant differences between PSO and APSO patients in rates of complications (overall 33.7% vs 42.3%, p = 0.227; neurological 5.9% vs 3.9%, p = 0.547; medical 20.7% vs 25.0%, p = 0.482; and surgical 6.5% vs 11.5%, p = 0.191, respectively). However, the APSO group required significantly longer stays in the ICU (3.1 vs 2.3 days, p = 0.047) and hospital (10.8 vs 8.3 days, p = 0.002). At the 2-year follow-up, there were no significant differences in mechanical complications, including proximal junctional kyphosis (p = 0.352), pseudarthrosis (p = 0.980), rod fracture (p = 0.852), and reoperation (p = 0.600).

CONCLUSIONS

ASD patients with significant coronal imbalance often have severe concurrent sagittal deformity. APSO is a powerful and effective technique to achieve multiplanar correction without higher risk of morbidity and complications compared with PSO for sagittal imbalance. However, APSO is associated with slightly longer ICU and hospital stays.

Single- versus dual-attending strategy for spinal deformity surgery: 2-year experience and systematic review of the literature

OBJECTIVE

Adult spinal deformity (ASD) surgery is complex and associated with high morbidity and complication rates. There is growing evidence in the literature for the beneficial effects of an approach to surgery in which two attending physicians rather than a single attending physician perform surgery for and oversee the surgical care of a single patient in a dual-attending care model. The authors developed a dual-attending care collaboration in August 2017 in which a neurosurgeon and an orthopedic surgeon mutually operated on patients with ASD.

METHODS

The authors recorded data for 2 years of experience with ASD patients operated on by dual attending surgeons. Analyses included estimated blood loss (EBL), transfusions, length of stay (LOS), discharge disposition, complication rates, emergency room visits and readmissions, subjective health status improvement, and disability (Oswestry Disability Index [ODI] score) and pain (visual analog scale [VAS] score) at last follow-up. In addition, the pertinent literature for dual-attending spinal deformity correction was systematically reviewed.

RESULTS

The study group comprised 19 of 254 (7.5%) consecutively operated patients who underwent thoracolumbar fusion during the period from January 2017 to June 2019 (68.4% female; mean patient age 65.1 years, ODI score 44.5, VAS pain score 6.8). The study patients were matched by age, sex, anesthesia risk, BMI, smoking status, ODI score, VAS pain score, prior spine surgeries, and basic operative characteristics (type of interbody implants, instrumented segments, pelvic fixation) to 19 control patients (all p > 0.05). There was a trend toward less EBL (mean 763 vs 1524 ml, p = 0.059), fewer intraoperative red blood cell transfusions (mean 0.5 vs 2.3, p = 0.079), and fewer 90-day readmissions (0% vs 15.8%, p = 0.071) in the dual-attending group. LOS and discharge disposition were similar, as were the rates of any < 30-day postsurgery complications, < 90-day postsurgery emergency room visits, and reoperations, and ODI and VAS pain scores at last follow-up (all p > 0.05). At last follow-up, 94.7% vs 68.4% of patients in the dual- versus single-attending group stated their health status had improved (p = 0.036). In the authors' literature search of prior articles on spinal deformity correction, 5 of 8 (62.5%) articles reported lower EBL and 6 of 8 (75%) articles reported significantly lower operation duration in dual-attending cases. The literature contained differing results with regard to complication- or reoperation-sparing effects associated with dual-attending cases. Similar clinical outcomes of dual- versus single-attending cases were reported.

CONCLUSIONS

Establishing a dual-attending care management platform for ASD correction was feasible at the authors' institution. Results of the use of a dual-attending strategy at the authors' institution were favorable. Positive safety and outcome profiles were found in articles on this topic identified by a systematic literature review.

Outcomes in single-level posterior cervical spine surgeries performed in the sitting and prone positions

OBJECTIVE

The sitting or semisitting position in neurosurgery allows for several technical advantages, including improved visualization of the surgical field. However, it has also been associated with an increased risk of venous air embolisms and positioning-related complications that limit its commonplace adoption. The authors report a large, single-center series of cervical spine procedures performed with patients in the sitting or prone position in order to assess the perceived risk of intraoperative and postoperative complications associated with the sitting position.

METHODS

Noninstrumented, single-level posterior cervical spine procedures performed with patients in the sitting/semisitting or prone position from 2000 to 2016 at a single institution were reviewed. Institutional abstraction tools (DataMart and Chart Plus) were used to collect data from the medical records. The two positions were compared with regard to preoperative factors, intraoperative variables, and postoperative outcomes. Multivariable logistic regression models were fitted for 30-day readmission, 30-day return to the operating room, and complication rates.

RESULTS

A total of 750 patients (sitting, n = 480; prone, n = 270) were analyzed. The median age was 53 years for those who underwent surgery in the prone position and 50 years for those who underwent surgery in the sitting position (IQRs 45-62 years and 43-60 years, respectively), and 35% of the patients were female. Sitting cases were associated with significantly longer anesthetic times (221 minutes [range 199-252 minutes] vs 205 minutes [range 179-254 minutes]) and operative times (126 minutes [range 101-163 minutes] vs 149 minutes [120-181 minutes]). Cardiorespiratory events in the postanesthesia care unit (PACU) were comparable between the two groups, with the exception of episodes of apnea (2.6% vs 0.6%, p = 0.041) and hypoventilation (4.4% vs 0.8%, p < 0.003), which were more frequent in the prone-position cohort. On multivariable analysis, the effect of the sitting versus the prone position was not significant for 30-day readmission (OR 0.77, 95% CI 0.34-1.71, p = 0.52) or reoperation (OR 0.71, 95% CI 0.31-1.60, p = 0.40). The sitting position was associated with lower odds of developing any complication (OR 0.31, 95% CI 0.16-0.62, p < 0.001).

CONCLUSIONS

Based on the intraoperative and postoperative complications chosen in this study, the sitting position confers a similar safety profile to the prone position. This can be explained by a more anatomic positioning accounting for reduced temporary neurological deficits and reduced PACU-associated hypoventilation noted in this series. Nevertheless, the findings may also reflect institutional familiarity, experience, and mastery of this position type, and outcomes may not reflect practices in general.

The impact of surgeon experience on perioperative complications and operative measures following thoracolumbar 3-column osteotomy for adult spinal deformity: overcoming the learning curve

OBJECTIVE

Posterior-based thoracolumbar 3-column osteotomy (3CO) is a formidable surgical procedure. Surgeon experience and case volume are known factors that influence surgical complication rates, but these factors have not been studied well in cases of adult spinal deformity (ASD). This study examines how surgeon experience affects perioperative complications and operative measures following thoracolumbar 3CO in ASD.

METHODS

A retrospective study was performed of a consecutive cohort of thoracolumbar ASD patients who underwent 3CO performed by the senior authors from 2006 to 2018. Multivariate analysis was used to assess whether experience (years of experience and/or number of procedures) is associated with perioperative complications, operative duration, and blood loss.

RESULTS

A total of 362 patients underwent 66 vertebral column resections (VCRs) and 296 pedicle subtraction osteotomies (PSOs). The overall complication rate was 29.4%, and the surgical complication rate was 8.0%. The rate of postoperative neurological deficits was 6.2%. There was a trend toward lower overall complication rates with greater operative years of experience (from 44.4% to 28.0%) (p = 0.115). Years of operative experience was associated with a significantly lower rate of neurological deficits (p = 0.027); the incidence dropped from 22.2% to 4.0%. The mean operative time was 310.7 minutes overall. Both increased years of experience and higher case numbers were significantly associated with shorter operative times (p < 0.001 and p = 0.001, respectively). Only operative years of experience was independently associated with operative times (p < 0.001): 358.3 minutes from 2006 to 2008 to 275.5 minutes in 2018 (82.8 minutes shorter). Over time, there was less deviation and more consistency in operative times, despite the implementation of various interventions to promote fusion and prevent construct failure: utilization of multiple-rod constructs (standard, satellite, and nested rods), bone morphogenetic protein, vertebroplasty, and ligament augmentation. Of note, the use of tranexamic acid did not significantly lower blood loss.

CONCLUSIONS

Surgeon years of experience, rather than number of 3COs performed, was a significant factor in mitigating neurological complications and improving quality measures following thoracolumbar 3CO for ASD. The 3- to 5-year experience mark was when the senior surgeon overcame a learning curve and was able to minimize neurological complication rates. There was a continuous decrease in operative time as the surgeon's experience increased; this was in concurrence with the implementation of additional preventative surgical interventions. Ongoing practice changes should be implemented and can be done safely, but it is imperative to self-assess the risks and benefits of those practice changes.

Prospective multicenter assessment of complication rates associated with adult cervical deformity surgery in 133 patients with minimum 1-year follow-up

OBJECTIVE

Although surgical treatment can provide significant improvement of symptomatic adult cervical spine deformity (ACSD), few reports have focused on the associated complications. The objective of this study was to assess complication rates at a minimum 1-year follow-up based on a prospective multicenter series of ACSD patients treated surgically.

METHODS

A prospective multicenter database of consecutive operative ACSD patients was reviewed for perioperative (< 30 days), early (30-90 days), and delayed (> 90 days) complications with a minimum 1-year follow-up. Enrollment required at least 1 of the following: cervical kyphosis > 10°, cervical scoliosis > 10°, C2-7 sagittal vertical axis > 4 cm, or chin-brow vertical angle > 25°.

RESULTS

Of 167 patients, 133 (80%, mean age 62 years, 62% women) had a minimum 1-year follow-up (mean 1.8 years). The most common diagnoses were degenerative (45%) and iatrogenic (17%) kyphosis. Almost 40% of patients were active or past smokers, 17% had osteoporosis, and 84% had at least 1 comorbidity. The mean baseline Neck Disability Index and modified Japanese Orthopaedic Association scores were 47 and 13.6, respectively. Surgical approaches were anterior-only (18%), posterior-only (47%), and combined (35%). A total of 132 complications were reported (54 minor and 78 major), and 74 (56%) patients had at least 1 complication. The most common complications included dysphagia (11%), distal junctional kyphosis (9%), respiratory failure (6%), deep wound infection (6%), new nerve root motor deficit (5%), and new sensory deficit (5%). A total of 4 deaths occurred that were potentially related to surgery, 2 prior to 1-year follow-up (1 cardiopulmonary and 1 due to obstructive sleep apnea and narcotic use) and 2 beyond 1-year follow-up (both cardiopulmonary and associated with revision procedures). Twenty-six reoperations were performed in 23 (17%) patients, with the most common indications of deep wound infection (n = 8), DJK (n = 7), and neurological deficit (n = 6). Although anterior-only procedures had a trend toward lower overall (42%) and major (21%) complications, rates were not significantly different from posterior-only (57% and 33%, respectively) or combined (61% and 37%, respectively) approaches (p = 0.29 and p = 0.38, respectively).

CONCLUSIONS

This report provides benchmark rates for ACSD surgery complications at a minimum 1-year (mean 1.8 years) follow-up. The marked health and functional impact of ACSD, the frail population it affects, and the high rates of surgical complications necessitate a careful risk-benefit assessment when contemplating surgery. Collectively, these findings provide benchmarks for complication rates and may prove useful for patient counseling and efforts to improve the safety of care.

Complication profile associated with S1 pedicle subtraction osteotomy compared with 3-column osteotomies at other thoracolumbar levels for adult spinal deformity: series of 405 patients with 9 S1 osteotomies

OBJECTIVE

There is an increased recognition of disproportional lumbar lordosis (LL) and artificially high pelvic incidence (PI) as a cause for positive sagittal imbalance and spinal pelvic mismatch. For such cases, a sacral pedicle subtraction osteotomy (PSO) may be indicated, although its morbidity is not well described. In this study, the authors evaluate the specific complication risks associated with S1 PSO.

METHODS

A retrospective review of all adult spinal deformity patients who underwent a 3-column osteotomy (3CO) for thoracolumbar deformity from 2006 to 2019 was performed. Demographic, clinical baseline, and radiographic parameters were recorded. The primary outcome of interest was perioperative complications (surgical, neurological, and medical). Secondary outcomes of interest included case length, blood loss, and length of stay. Multivariate analysis was used to assess the risk of S1 PSO compared with 3CO at other levels.

RESULTS

A total of 405 patients underwent 3CO in the following locations: thoracic (n = 55), L1 (n = 25), L2 (n = 29), L3 (n = 141), L4 (n = 129), L5 (n = 17), and S1 (n = 9). After S1 PSO, there were significant improvements in the sagittal vertical axis (14.8 cm vs 6.7 cm, p = 0.004) and PI-LL mismatch (31.7° vs 9.6°, p = 0.025) due to decreased PI (80.3° vs 65.9°, p = 0.006). LL remained unchanged (48.7° vs 57.8°, p = 0.360). The overall complication rate was 27.4%; the surgical, neurological, and medical complication rates were 7.7%, 6.2%, and 20.0%, respectively. S1 PSO was associated with significantly higher rates of overall complications: thoracic (29.1%), L1 (32.0%), L2 (31.0%), L3 (19.9%), L4 (32.6%), L5 (11.8%), and S1 (66.7%) (p = 0.018). Similarly, an S1 PSO was associated with significantly higher rates of surgical (thoracic [9.1%], L1 [4.0%], L2 [6.9%], L3 [5.7%], L4 [10.9%], L5 [5.9%], and S1 [44.4%], p = 0.006) and neurological (thoracic [9.1%], L1 [0.0%], L2 [6.9%], L3 [2.8%], L4 [7.0%], L5 [5.9%], and S1 [44.4%], p < 0.001) complications. On multivariate analysis, S1 PSO was independently associated with higher odds of overall (OR 7.93, p = 0.013), surgical (OR 20.66, p = 0.010), and neurological (OR 14.75, p = 0.007) complications.

CONCLUSIONS

S1 PSO is a powerful technique for correction of rigid sagittal imbalance due to an artificially elevated PI in patients with rigid high-grade spondylolisthesis and chronic sacral fractures. However, the technique and intraoperative corrective maneuvers are challenging and associated with high surgical and neurological complications. Additional investigations into the learning curve associated with S1 PSO and complication prevention are needed.

The impact of platelet-rich plasma on postoperative outcomes after spinal fusion: a systematic review and meta-analysis

OBJECTIVE

Platelet-rich plasma (PRP) is a biological agent obtained by centrifuging a sample of blood and retrieving a high concentration of platelets and plasma components. The concentrate is then stimulated for platelet secretion of various growth factors and cytokines. Although it is not widely used in clinical practice, its role in augmenting bony union among patients undergoing spinal fusion has been assessed in several clinical studies. The objective of this study was to perform a systematic review and meta-analysis of the existing literature to determine the efficacy of PRP use in spinal fusion procedures.

METHODS

A comprehensive literature search was conducted using PubMed, Scopus, and EMBASE for studies from all available dates. From eligible studies, data regarding the fusion rate and method of assessing fusion, estimated blood loss (EBL), and baseline and final visual analog scale (VAS) scores were collected as the primary outcomes of interest. Patients were grouped by those undergoing spinal fusion with PRP and bone graft (PRP group) and those only with bone graft (graft-only group).

RESULTS

The literature search resulted in 207 articles. Forty-five full-text articles were screened, of which 11 studies were included, resulting in a meta-analysis including 741 patients. Patients without PRP were more likely to have a successful fusion at the last follow-up compared with those with PRP in their bone grafts (OR 0.53, 95% CI 0.34-0.84; p = 0.006). There was no statistically significant difference with regard to change in VAS scores (OR 0.00, 95% CI -2.84 to 2.84; p > 0.99) or change in EBL (OR 3.67, 95% CI -67.13-74.48; p = 0.92) between the groups.

CONCLUSIONS

This study found that the additional use of PRP was not associated with any significant improvement in patient-reported outcomes and was actually found to be associated with lower fusion rates compared with standard grafting techniques. Thus, PRP may have a limited role in augmenting spinal fusion.

Predictors of inpatient admission in the setting of anterior lumbar interbody fusion: a Minimally Invasive Spine Study Group (MISSG) investigation

OBJECTIVE

While the anterior lumbar interbody fusion (ALIF) procedure may be amenable to ambulatory surgery, it has been hypothesized that limitations such as the risk of postoperative ileus and vascular complications have hindered transition of this procedure to the outpatient setting. Identification of independent risk factors predisposing patients to inpatient stays of ≥ 24 hours after ALIF may facilitate better postsurgical outcomes, target modifiable risk factors, and assist in the development of screening tools to transition appropriate patients to the ambulatory surgery center (ASC) setting for this procedure. The purpose of this study was to identify the most relevant risk factors that predispose patients to ≥ 24-hour admission following ALIF.

METHODS

A prospectively maintained surgical registry was reviewed for patients undergoing single ALIF between May 2006 and December 2019. Demographics, preoperative diagnosis, perioperative variables, and postoperative complications were evaluated according to their relative risk (RR) elevation for an inpatient stay of ≥ 24 hours. A Poisson regression model was used to evaluate predictors of inpatient stays of ≥ 24 hours. Risk factors for inpatient admission of ≥ 24 hours were identified with a stepwise backward regression model.

RESULTS

A total of 111 patients underwent single-level ALIF (50.9% female and 52.6% male, ≤ 50 years old). Eleven (9.5%) patients were discharged in < 24 hours and 116 remained admitted for ≥ 24 hours. The average inpatient stay was > 2 days (53.7 hours). The most common postoperative complications were fever (body temperature ≥ 100.4°F; n = 4, 3.5%) and blood transfusions (n = 4, 3.5%). Bivariate analysis revealed a preoperative diagnosis of retrolisthesis or lateral listhesis to elevate the RR for an inpatient stay of ≥ 24 hours (RR 1.11, p = 0.001, both diagnoses). Stepwise multivariate analysis demonstrated significant predictors for inpatient stays of ≥ 24 hours to be an operation on L4-5, coexisting degenerative disc disease (DDD) with foraminal stenosis, and herniated nucleus pulposus (RR 1.11, 95% CI 1.03-1.20, p = 0.009, all covariates).

CONCLUSIONS

This study provides data regarding the incidence of demographic and perioperative characteristics and postoperative complications as they pertain to patients undergoing single-level ALIF. This preliminary investigation identified the most relevant risk factors to be considered before appropriately transitioning ALIF procedures to the ASC. Further studies of preoperative characteristics are needed to elucidate ideal ASC ALIF patients.

The impact of obesity on perioperative complications in patients undergoing anterior lumbar interbody fusion

OBJECTIVE

Anterior approaches to the lumbar spine provide wide exposure that facilitates placement of large grafts with high fusion rates. There are limited data on the effects of obesity on perioperative complications.

METHODS

Data from consecutive patients undergoing anterior lumbar interbody fusion (ALIF) from 2007 to 2016 at a single academic center were analyzed. The primary outcome was any perioperative complication. Complications were divided into those occurring intraoperatively and those occurring postoperatively. Multivariate logistic regression was used to assess the association of obesity and other variables with these complications. An estimation table was used to identify a body mass index (BMI) threshold associated with increased risk of postoperative complication.

RESULTS

A total of 938 patients were identified, and the mean age was 57 years; 511 were females (54.5%). The mean BMI was 28.7 kg/m2, with 354 (37.7%) patients classified as obese (BMI ≥ 30 kg/m2). Forty patients (4.3%) underwent a lateral transthoracic approach, while the remaining 898 (95.7%) underwent a transabdominal retroperitoneal approach. Among patients undergoing transabdominal retroperitoneal ALIF, complication rates were higher for obese patients than for nonobese patients (37.0% vs 28.7%, p = 0.010), a difference that was driven primarily by postoperative complications (36.1% vs 26.0%, p = 0.001) rather than intraoperative complications (3.2% vs 4.3%, p = 0.416). Obese patients had higher rates of ileus (11.7% vs 7.2%, p = 0.020), wound complications (11.4% vs 3.4%, p < 0.001), and urinary tract infections (UTI) (5.0% vs 2.5%, p = 0.049). In a multivariate model, age, obesity, and number of ALIF levels fused were associated with an increased risk of postoperative complication. An estimation table including 19 candidate cut-points, odds ratios, and adjusted p values found a BMI ≥ 31 kg/m2 to have the highest association with postoperative complication (p = 0.012).

CONCLUSIONS

Obesity is associated with increased postoperative complications in ALIF, including ileus, wound complications, and UTI. ALIF is a safe and effective procedure. However, patients with a BMI ≥ 31 kg/m2 should be counseled on their increased risks and warrant careful preoperative medical optimization and close monitoring in the postoperative setting.

A novel technique for awake, minimally invasive transforaminal lumbar interbody fusion: technical note

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is associated with improved patient-reported outcomes in well-selected patients. Recently, some neurosurgeons have aimed to further improve outcomes by utilizing multimodal methods to avoid the use of general anesthesia. Here, the authors report on the use of a novel awake technique for MI-TLIF in two patients. They describe the successful use of liposomal bupivacaine in combination with a spinal anesthetic to allow for operative analgesia.

Rotational thromboelastometry-guided transfusion during lumbar pedicle subtraction osteotomy for adult spinal deformity: preliminary findings from a matched cohort study

OBJECTIVESignificant blood loss and coagulopathy are often encountered during adult spinal deformity (ASD) surgery, and the optimal intraoperative transfusion algorithm is debatable. Rotational thromboelastometry (ROTEM), a functional viscoelastometric method for real-time hemostasis testing, may allow early identification of coagulopathy and improve transfusion practices. The objective of this study was to investigate the effect of ROTEM-guided blood product management on perioperative blood loss and transfusion requirements in ASD patients undergoing correction with pedicle subtraction osteotomy (PSO).METHODSThe authors retrospectively reviewed patients with ASD who underwent single-level lumbar PSO at the University of Virginia Health System. All patients who received ROTEM-guided blood product transfusion between 2015 and 2017 were matched in a 1:1 ratio to a historical cohort treated using conventional laboratory testing (control group). Co-primary outcomes were intraoperative estimated blood loss (EBL) and total blood product transfusion volume. Secondary outcomes were perioperative transfusion requirements and postoperative subfascial drain output.RESULTSThe matched groups (ROTEM and control) comprised 17 patients each. Comparison of matched group baseline characteristics demonstrated differences in female sex and total intraoperative dose of intravenous tranexamic acid (TXA). Although EBL was comparable between ROTEM versus control (3200.00 ± 2106.24 ml vs 3874.12 ± 2224.22 ml, p = 0.36), there was a small to medium effect size (Cohen's d = 0.31) on EBL reduction with ROTEM. The ROTEM group had less total blood product transfusion volume (1624.18 ± 1774.79 ml vs 2810.88 ± 1847.46 ml, p = 0.02), and the effect size was medium to large (Cohen's d = 0.66). This difference was no longer significant after adjusting for TXA (β = -0.18, 95% confidence interval [CI] -1995.78 to 671.64, p = 0.32). More cryoprecipitate and less fresh frozen plasma (FFP) were transfused in the ROTEM group patients (cryoprecipitate units: 1.24 ± 1.20 vs 0.53 ± 1.01, p = 0.03; FFP volume: 119.76 ± 230.82 ml vs 673.06 ± 627.08 ml, p < 0.01), and this remained significant after adjusting for TXA (cryoprecipitate units: β = 0.39, 95% CI 0.05 to 1.73, p = 0.04; FFP volume: β = -0.41, 95% CI -772.55 to -76.30, p = 0.02). Drain output was lower in the ROTEM group and remained significant after adjusting for TXA.CONCLUSIONSFor ASD patients treated using lumbar PSO, more cryoprecipitate and less FFP were transfused in the ROTEM group compared to the control group. These preliminary findings suggest ROTEM-guided therapy may allow early identification of hypofibrinogenemia, and aggressive management of this may reduce blood loss and total blood product transfusion volume. Additional prospective studies of larger cohorts are warranted to identify the appropriate subset of ASD patients who may benefit from intraoperative ROTEM analysis.

Quantifying the impact of surgical decompression on quality of life and identification of factors associated with outcomes in patients with symptomatic metastatic spinal cord compression

OBJECTIVE

Metastatic spinal cord compression (MSCC) imposes significant impairment on patient quality of life and often requires immediate surgical intervention. In this study the authors sought to estimate the impact of surgical intervention on patient quality of life in the form of mean quality-adjusted life years (QALY) gained and identify factors associated with positive outcomes.

METHODS

The authors performed a retrospective chart review and collected data for patients who had neurological symptoms resulting from radiologically and histologically confirmed MSCC and were treated with surgical decompression during the last 12 years.

RESULTS

A total of 151 patients were included in this study (mean age 60.4 years, 57.6% males). The 5 most common metastatic tumor types were lung, multiple myeloma, renal, breast, and prostate cancer. The majority of patients had radioresistant tumors (82.7%) and had an active primary site at presentation (67.5%). The median time from tumor diagnosis to cord compression was 12 months and the median time from identification of cord compression to death was 4 months. Preoperative presenting symptoms included motor weakness (70.8%), pain (70.1%), sensory disturbances (47.6%), and bowel or bladder disturbance (31.1%). The median estimated blood loss was 500 mL and the average length of hospital stay was 10.3 days. About 18% of patients had postoperative complications and the mean follow-up was 7 months. The mean pre- and postoperative ECOG (Eastern Cooperative Oncology Group) performance status grades were 3.2 and 2.4, respectively. At follow-up, 58.3% of patients had improved status, 31.5% had no improvement, and 10.0% had worsening of functional status. The mean QALY gained per year in the entire cohort was 0.55. The mean QALY gained in the first 6 months was 0.1 and in the first year was 0.4. For patients who lived 1-2, 2-3, 3-4, or 4-5 years, the mean QALY gained were 0.8, 1.4, 1.7, and 2.3, respectively. Preoperative motor weakness, bowel dysfunction, bladder dysfunction, and ASA (American Society of Anesthesiologists) class were identified as independent predictors inversely associated with good outcome.

CONCLUSIONS

The mean QALY gained from surgical decompression in the first 6 months and first year equals 1.2 months and 5 months of life in perfect health, respectively. These findings suggest that surgery might also be beneficial to patients with life expectancy < 6 months.

Indirect decompression with lateral interbody fusion for severe degenerative lumbar spinal stenosis: minimum 1-year MRI follow-up

OBJECTIVE

The use of indirect decompression surgery for severe canal stenosis remains controversial. The purpose of this study was to investigate the efficacy of lateral interbody fusion (LIF) without posterior decompression in degenerative lumbar spinal spondylosis with severe stenosis on preoperative MRI.

METHODS

This is a retrospective case series from a single academic institution. The authors included 42 patients (45 surgical levels) who were preoperatively diagnosed with severe degenerative lumbar stenosis on MRI based on the previously published Schizas classification. These patients underwent LIF with supplemental pedicle screw fixation without posterior decompression. Surgical levels were limited to L3-4 and/or L4-5. All patients satisfied the minimum 1-year MRI follow-up. The authors compared the cross-sectional area (CSA) of the thecal sac and the clinical outcome scores (Japanese Orthopaedic Association [JOA] score) preoperatively, immediately postoperatively, and at the 1-year follow-up. Fusion status and disc height were evaluated based on CT scans obtained at the 1-year follow-up.

RESULTS

The CSA improved over time, increasing from 54.5 ± 19.2 mm2 preoperatively to 84.7 ± 31.8 mm2 at 3 weeks postoperatively and to 132.6 ± 37.5 mm2 at the last follow-up (average 28.3 months) (p < 0.001). The JOA score significantly improved over time (preoperatively 16.1 ± 4.1, 3 months postoperatively 24.4 ± 4.0, and 1-year follow-up 25.7 ± 2.9; p < 0.001). The fusion rate at the 1-year follow-up was 88.8%, and disc heights were significantly restored (preoperative, 6.3 mm and postoperative, 9.6 mm; p < 0.001). Patients showing poor CSA expansion (< 200% expansion rate) at the last follow-up had a higher prevalence of pseudarthrosis than patients with significant CSA expansion (> 200% expansion rate) (25.0% vs 3.4%, p < 0.001). No major perioperative complications were observed.

CONCLUSIONS

LIF with indirect decompression for degenerative lumbar disease with severe canal stenosis provided successful clinical outcomes, including restoration of disc height and indirect expansion of the thecal sac. Severe canal stenosis diagnosed on preoperative MRI itself is not a contraindication for indirect decompression surgery.

Anterior selective stabilization combined with laminoplasty for cervical myelopathy due to massive ossification of the posterior longitudinal ligament: report of early outcomes in 14 patients

OBJECTIVE

Surgical management of massive ossification of the posterior longitudinal ligament (OPLL) is challenging. To reduce surgical complications, the authors have performed anterior selective stabilization combined with laminoplasty (antSS+LP) for massive OPLL since 2012. This study aimed to elucidate the short-term outcome of the antSS+LP procedure.

METHODS

The authors' analysis was based on data from 14 patients who underwent antSS+LP for cervical myelopathy caused by massive OPLL and were followed up for at least 2 years after surgery (mean follow-up duration 3.3 years). Clinical outcome was evaluated preoperatively, at 6 months and 1 year postoperatively, and at the final follow-up using the Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy and the recovery rate of the JOA score. The following radiographic parameters were measured preoperatively, immediately after surgery, at 1 year after surgery, and at the final follow-up: the C2-7 angle, measured on lateral plain radiographs, and the segmental lordosis angle (SLA), measured on sagittal CT scans. The correlation between radiographic parameters and clinical outcomes was evaluated.

RESULTS

The mean JOA score increased from 10.4 before surgery to 13.6 and 13.8 at 6 months and 1 year after surgery, respectively; at the final follow-up the mean score was 13.4. This postoperative recovery was significant (p = 0.004) and was maintained until the final follow-up. No patient required revision surgery due to postoperative neurological deterioration. However, the C2-7 angle gradually deteriorated postoperatively. Similarly, the SLA was significantly increased immediately after surgery, but the improvement was not maintained. The recovery rate at the final follow-up correlated positively with the change in C2-7 angle (r = 0.60, p = 0.03) and the change in SLA (r = 0.72, p < 0.01).

CONCLUSIONS

AntSS+LP is safe and effective and may be an alternative to anterior decompression and fusion for the treatment of patients with massive OPLL. No postoperative neurological complications or significant postoperative exacerbation of neck pain were observed in our case series. Not only reducing intervertebral motion and decompressing the canal at the maximal compression level but also acquiring segmental lordosis at the maximal compression level are crucial factors for achieving successful outcomes of antSS+LP.

Spinal column shortening versus revision detethering for recurrent adult tethered cord syndrome: a preliminary comparison of perioperative and clinical outcomes

OBJECTIVE

Recurrent tethered cord syndrome (TCS), believed to result from tension on the distal portion of the spinal cord, causes a constellation of neurological symptoms. Detethering surgery has been the traditional treatment for TCS. However, in cases of recurrent TCS, there is a risk of new neurological deficits developing, and subsequent retethering is difficult to prevent. Spinal column shortening has been proposed as an alternative technique to reduce the tension on the spinal cord without incurring the morbidity of revision surgery on the spinal cord. The authors compared the perioperative outcomes and morbidity of patients who were treated with one or the other procedure.

METHODS

The medical records of 16 adult patients with recurrent TCS who were treated between 2005 and 2018 were reviewed. Eight patients underwent spinal column shortening, and 8 patients underwent revision detethering surgery. Patient demographics, clinical outcomes, and perioperative factors were analyzed. The authors include a video to illustrate their technique of spinal column shortening.

RESULTS

Within the spinal column shortening group, no patients experienced any complications, and all 8 patients either improved or stabilized with regard to lower-extremity and bowel and bladder function. Within the revision detethering group, 2 patients had worsening of lower-extremity strength, 3 patients had worsening of bowel and bladder function, and 1 patient had improvement in bladder function. Also, 3 patients had wound-related complications. The median estimated blood loss was 731 ml in the shortening group and 163 ml in the revision detethering group. The median operative time was 358 minutes in the shortening group and 226 minutes in the revision detethering group.

CONCLUSIONS

Clinical outcomes were comparable between the groups, but none of the spinal column shortening patients experienced worsening, whereas 3 of the revision detethering patients did and also had wound-related complications. Although the operative times and blood loss were higher in the spinal column shortening group, this procedure may be an alternative to revision detethering in extremely scarred or complex wound revision cases.

The effectiveness of tranexamic acid on operative and perioperative blood loss in long-segment spinal fusions: a consecutive series of 119 primary procedures

OBJECTIVE

The aim of this study was to determine if the use of tranexamic acid (TXA) in long-segment spinal fusion surgery can help reduce perioperative blood loss, transfusion requirements, and morbidity.

METHODS

In this retrospective single-center study, the authors included 119 consecutive patients who underwent thoracolumbar fusion spanning at least 4 spinal levels from October 2016 to February 2019. Blood loss, transfusion requirements, perioperative morbidity, and adverse thrombotic events were compared between a cohort receiving intravenous TXA and a control group that did not.

RESULTS

There was no significant difference in any measure of intraoperative blood loss (1514.3 vs 1209.1 mL, p = 0.29) or transfusion requirement volume between the TXA and control groups despite a higher number of pelvic fusion procedures in the TXA group (85.9% vs 62.5%, p = 0.003). Postoperative transfusion volume was significantly lower in TXA patients (954 vs 572 mL, p = 0.01). There was no difference in the incidence of thrombotic complications between the groups.

CONCLUSIONS

TXA appears to provide a protective effect against blood loss in long-segment spine fusion surgery specifically when pelvic dissection and fixation is performed. TXA also seems to decrease postoperative transfusion requirements without increasing the risk of adverse thrombotic events.

Index episode-of-care propensity-matched comparison of transforaminal lumbar interbody fusion (TLIF) techniques: open traditional TLIF versus midline lumbar interbody fusion (MIDLIF) versus robot-assisted MIDLIF

OBJECTIVE

Posterior fixation with interbody cage placement can be accomplished via numerous techniques. In an attempt to expedite recovery by limiting muscle dissection, midline lumbar interbody fusion (MIDLIF) has been described. More recently, the authors have developed a robot-assisted MIDLIF (RA-MIDLIF) technique. The purpose of this study was to compare the index episode-of-care (iEOC) parameters between patients undergoing traditional open transforaminal lumbar interbody fusion (tTLIF), MIDLIF, and RA-MIDLIF.

METHODS

A retrospective review of a prospective, multisurgeon surgical database was performed. Consecutive patients undergoing 1- or 2-level tTLIF, MIDLIF, or RA-MIDLIF for degenerative lumbar conditions were identified. Patients in each cohort were propensity matched based on age, sex, smoking status, BMI, diagnosis, American Society of Anesthesiologists (ASA) class, and number of levels fused. Index EOC parameters such as length of stay (LOS), estimated blood loss (EBL), operating room (OR) time, and actual, direct hospital costs for the index surgical visit were analyzed.

RESULTS

Of 281 and 249 patients undergoing tTLIF and MIDLIF, respectively, 52 cases in each cohort were successfully propensity matched to the authors' first 55 RA-MIDLIF cases. Consistent with propensity matching, there was no significant difference in age, sex, BMI, diagnosis, ASA class, or levels fused. Spondylolisthesis was the most common indication for surgery in all cohorts. The mean total iEOC was similar across all cohorts. Patients undergoing RA-MIDLIF had a shorter average LOS (1.53 days) than those undergoing either MIDLIF (2.71 days) or tTLIF (3.58 days). Both MIDLIF and RA-MIDLIF were associated with lower EBL and less OR time compared with tTLIF.

CONCLUSIONS

Despite concerns for additional cost and time while introducing navigation or robotic technology, a propensity-matched comparison of the authors' first 52 RA-MIDLIF surgeries with tTLIF and MIDLIF showed promising results for reducing OR time, EBL, and LOS without increasing cost.

A comparison of spinal laser interstitial thermotherapy with open surgery for metastatic thoracic epidural spinal cord compression

OBJECTIVE

The proximity of the spinal cord to compressive metastatic lesions limits radiosurgical dosing. Open surgery is used to create safe margins around the spinal cord prior to spinal stereotactic radiosurgery (SSRS) but carries the risk of potential surgical morbidity and interruption of systemic oncological treatment. Spinal laser interstitial thermotherapy (SLITT) in conjunction with SSRS provides local control with less morbidity and a shorter interval to resume systemic treatment. The authors present a comparison between SLITT and open surgery in patients with metastatic thoracic epidural spinal cord compression to determine the advantages and disadvantages of each method.

METHODS

This is a matched-group design study comprising patients from a single institution with metastatic thoracic epidural spinal cord compression that was treated either with SLITT or open surgery. The two cohorts defined by the surgical treatment comprised patients with epidural spinal cord compression (ESCC) scores of 1c or higher and were deemed suitable for either treatment. Demographics, pre- and postoperative ESCC scores, histology, morbidity, hospital length of stay (LOS), complications, time to radiotherapy, time to resume systemic therapy, progression-free survival (PFS), and overall survival (OS) were compared between groups.

RESULTS

Eighty patients were included in this analysis, 40 in each group. Patients were treated between January 2010 and December 2016. There was no significant difference in demographics or clinical characteristics between the cohorts. The SLITT cohort had a smaller postoperative decrease in the extent of ESCC but a lower estimated blood loss (117 vs 1331 ml, p < 0.001), shorter LOS (3.4 vs 9 days, p < 0.001), lower overall complication rate (5% vs 35%, p = 0.003), fewer days until radiotherapy or SSRS (7.8 vs 35.9, p < 0.001), and systemic treatment (24.7 vs 59 days, p = 0.015). PFS and OS were similar between groups (p = 0.510 and p = 0.868, respectively).

CONCLUSIONS

The authors' results have shown that SLITT plus XRT is not inferior to open decompression surgery plus XRT in regard to local control, with a lower rate of complications and faster resumption of oncological treatment. A prospective randomized controlled study is needed to compare SLITT with open decompressive surgery for ESCC.

Upper-thoracic versus lower-thoracic upper instrumented vertebra in adult spinal deformity patients undergoing fusion to the pelvis: surgical decision-making and patient outcomes

OBJECTIVE

Optimal patient selection for upper-thoracic (UT) versus lower-thoracic (LT) fusion during adult spinal deformity (ASD) correction is challenging. Radiographic and clinical outcomes following UT versus LT fusion remain incompletely understood. The purposes of this study were: 1) to evaluate demographic, radiographic, and surgical characteristics associated with choice of UT versus LT fusion endpoint; and 2) to evaluate differences in radiographic, clinical, and health-related quality of life (HRQOL) outcomes following UT versus LT fusion for ASD.

METHODS

Retrospective review of a prospectively collected multicenter ASD database was performed. Patients with ASD who underwent fusion from the sacrum/ilium to the LT (T9-L1) or UT (T1-6) spine were compared for demographic, radiographic, and surgical characteristics. Outcomes including proximal junctional kyphosis (PJK), reoperation, rod fracture, pseudarthrosis, overall complications, 2-year change in alignment parameters, and 2-year HRQOL metrics (Lumbar Stiffness Disability Index, Scoliosis Research Society-22r questionnaire, Oswestry Disability Index) were compared after controlling for confounding factors via multivariate analysis.

RESULTS

Three hundred three patients (169 LT, 134 UT) were evaluated. Independent predictors of UT fusion included greater thoracic kyphosis (odds ratio [OR] 0.97 per degree, p = 0.0098), greater coronal Cobb angle (OR 1.06 per degree, p < 0.0001), and performance of a 3-column osteotomy (3-CO; OR 2.39, p = 0.0351). While associated with longer operative times (ratio 1.13, p < 0.0001) and greater estimated blood loss (ratio 1.31, p = 0.0018), UT fusions resulted in greater sagittal vertical axis improvement (-59.5 vs -41.0 mm, p = 0.0035) and lower PJK rates (OR 0.49, p = 0.0457). No significant differences in postoperative HRQOL measures, reoperation, or overall complication rates were detected between groups (all p > 0.1).

CONCLUSIONS

Greater deformity and need for 3-CO increased the likelihood of UT fusion. Despite longer operative times and greater blood loss, UT fusions resulted in better sagittal correction and lower 2-year PJK rates following surgery for ASD. While continued surveillance is necessary, this information may inform patient counseling and surgical decision-making.

Perioperative complications of spine surgery in patients 80 years of age or older: a multicenter prospective cohort study

OBJECTIVE

The number of spine surgeries performed in elderly patients is consistently increasing. However, to date the prevalence of and risk factors for perioperative complications remain unclear, especially in patients 80 years of age or older. This study had two goals: 1) determine the perioperative complications of spine surgery associated with patients 80 years of age or older; and 2) investigate the risk factors for perioperative systemic complications.

METHODS

In this paper, the authors describe a multicenter prospective cohort study. Seven spine centers with board-certified spine surgeons participated in this all-case investigation. A total of 270 consecutively enrolled patients (109 males and 161 females), 80 years of age or older, underwent spine surgery between January and December 2017. Patients with trauma, infection, or tumor were excluded in this cohort. Perioperative complications were defined as adverse events that occurred intraoperatively or within 30 days postoperatively. The patients' preoperative health status was determined using the following means of assessment: 1) the Charlson Comorbidity Index, 2) the American Society of Anesthesiologists Physical Status Classification System, 3) the Eastern Cooperative Oncology Group Performance Status (ECOG-PS), 4) the presence of sarcopenia, and 5) the Geriatric Nutritional Risk Index. Associations among patient age, preoperative health status, surgical factors (instrumentation surgery, operation time, number of spinal levels treated, and estimated blood loss), and perioperative systemic complications were analyzed.

RESULTS

Overall perioperative, surgical site, and minor systemic complications were observed in 20.0%, 8.1%, and 14.8% of patients, respectively. Major systemic complications, on the other hand, were not observed. The reoperation rate was low-only 4.1%. Multivariate analysis revealed that the ECOG-PS (p = 0.013), instrumentation surgery (p = 0.024), and an operation time longer than 180 minutes (p = 0.016) were associated with minor systemic complications.

CONCLUSIONS

To the best of the authors' knowledge, this is the first multicenter prospective all-case investigation of perioperative complications of spine surgery in elderly patients. Although decreased daily activity (ECOG-PS), instrumentation surgery, and longer operation time were associated with minor systemic complications, no major systemic complications were observed in these elderly patients. Thus, spine surgery can be safely performed in elderly patients 80 years of age or older.

Characteristics of false-positive alerts on transcranial motor evoked potential monitoring during pediatric scoliosis and adult spinal deformity surgery: an "anesthetic fade" phenomenon

OBJECTIVE

Transcranial motor evoked potential (TcMEP) monitoring may be valuable for predicting postoperative neurological complications with a high sensitivity and specificity, but one of the most frequent problems is the high false-positive rate. The purpose of this study was to clarify the differences in the risk factors for false-positive TcMEP alerts seen when performing surgery in patients with pediatric scoliosis and adult spinal deformity and to identify a method to reduce the false-positive rate.

METHODS

The authors retrospectively analyzed 393 patients (282 adult and 111 pediatric patients) who underwent TcMEP monitoring while under total intravenous anesthesia during spinal deformity surgery. They defined their cutoff (alert) point as a final TcMEP amplitude of ≤ 30% of the baseline amplitude. Patients with false-positive alerts were classified into one of two groups: a group with pediatric scoliosis and a group with adult spinal deformity.

RESULTS

There were 14 cases of false-positive alerts (13%) during pediatric scoliosis surgery and 62 cases of false-positive alerts (22%) during adult spinal deformity surgery. Compared to the true-negative cases during adult spinal deformity surgery, the false-positive cases had a significantly longer duration of surgery and greater estimated blood loss (both p < 0.001). Compared to the true-negative cases during pediatric scoliosis surgery, the false-positive cases had received a significantly higher total fentanyl dose and a higher mean propofol dose (0.75 ± 0.32 mg vs 0.51 ± 0.18 mg [p = 0.014] and 5.6 ± 0.8 mg/kg/hr vs 5.0 ± 0.7 mg/kg/hr [p = 0.009], respectively). A multivariate logistic regression analysis revealed that the duration of surgery (1-hour difference: OR 1.701; 95% CI 1.364-2.120; p < 0.001) was independently associated with false-positive alerts during adult spinal deformity surgery. A multivariate logistic regression analysis revealed that the mean propofol dose (1-mg/kg/hr difference: OR 3.117; 95% CI 1.196-8.123; p = 0.020), the total fentanyl dose (0.05-mg difference; OR 1.270; 95% CI 1.078-1.497; p = 0.004), and the duration of surgery (1-hour difference: OR 2.685; 95% CI 1.131-6.377; p = 0.025) were independently associated with false-positive alerts during pediatric scoliosis surgery.

CONCLUSIONS

Longer duration of surgery and greater blood loss are more likely to result in false-positive alerts during adult spinal deformity surgery. In particular, anesthetic doses were associated with false-positive TcMEP alerts during pediatric scoliosis surgery. The authors believe that false-positive alerts during pediatric scoliosis surgery, in particular, are caused by "anesthetic fade."

Assessment of radiographic and clinical outcomes of an articulating expandable interbody cage in minimally invasive transforaminal lumbar interbody fusion for spondylolisthesis

OBJECTIVE The inability to significantly improve sagittal parameters has been a limitation of minimally invasive surgery for transforaminal lumbar interbody fusion (MIS TLIF). Traditional cages have a limited capacity to restore lordosis. This study evaluates the use of a crescent-shaped articulating expandable cage (Altera) for MIS TLIF. METHODS This is a retrospective review of 1- and 2-level MIS TLIF. Radiographic outcomes included differences in segmental and lumbar lordosis, disc height, evidence of fusion, and any endplate violations. Clinical outcomes included the numeric rating scale for leg and back pain and the Oswestry Disability Index (ODI) for low-back pain. RESULTS Thirty-nine patients underwent single-level MIS TLIF, and 5 underwent 2-level MIS TLIF. The mean age was 63.1 years, with 64% women. On average, spondylolisthesis was corrected by 4.3 mm (preoperative = 6.69 mm, postoperative = 2.39 mm, p < 0.001), the segmental angle was improved by 4.94° (preoperative = 5.63°, postoperative = 10.58°, p < 0.001), and segmental height increased by 3.1 mm (preoperative = 5.09 mm, postoperative = 8.19 mm, p < 0.001). At 90 days after surgery the authors observed the following: a smaller postoperative sagittal vertical axis was associated with larger changes in back pain at 90 days (r = -0.558, p = 0.013); a larger decrease in spondylolisthesis was associated with greater improvements in ODI and back pain scores (r = -0.425, p = 0.043, and r = -0.43, p = 0.031, respectively); and a larger decrease in pelvic tilt (PT) was associated with greater improvements in back pain (r = -0.548, p = 0.043). For the 1-year PROs, the relationship between the change in PT and changes in ODI and numeric rating scale back pain were significant (r = 0.612, p = 0.009, and r = -0.803, p = 0.001, respectively) with larger decreases in PT associated with larger improvements in ODI and back pain. Overall for this study there was a 96% fusion rate. Fourteen patients were noted to have endplate violation on intraoperative fluoroscopy during placement of the cage. Only 3 of these had progression of their subsidence, with an overall subsidence rate of 6% (3 of 49) visible on postoperative CT. CONCLUSIONS The use of this expandable, articulating, lordotic, or hyperlordotic interbody cage for MIS TLIF provides a significant restoration of segmental height and segmental lordosis, with associated improvements in sagittal balance parameters. Patients treated with this technique had acceptable levels of fusion and significant reductions in pain and disability.

Perioperative acute neurological deficits in instrumented pediatric cervical spine fusions

OBJECTIVE

Pediatric cervical deformity is a complex disorder often associated with neurological deterioration requiring cervical spine fusion. However, limited literature exists on new perioperative neurological deficits in children. This study describes new perioperative neurological deficits in pediatric cervical spine instrumentation and fusion.

METHODS

A single-center review of pediatric cervical spine instrumentation and fusion during 2002-2018 was performed. Demographics, surgical characteristics, and neurological complications were recorded. Perioperative neurological deficits were defined as the deterioration of preexisting neurological function or the appearance of new neurological symptoms.

RESULTS

A total of 184 cases (160 patients, 57% male) with an average age of 12.6 ± 5.30 years (range 0.2-24.9 years) were included. Deformity (n = 39) and instability (n = 36) were the most frequent indications. Syndromes were present in 39% (n = 71), with Down syndrome (n = 20) and neurofibromatosis (n = 12) the most prevalent. Eighty-seven (48%) children presented with preoperative neurological deficits (16 sensory, 16 motor, and 55 combined deficits).A total of 178 (96.7%) cases improved or remained neurologically stable. New neurological deficits occurred in 6 (3.3%) cases: 3 hemiparesis, 1 hemiplegia, 1 quadriplegia, and 1 quadriparesis. Preoperative neurological compromise was seen in 4 (67%) of these new deficits (3 myelopathy, 1 sensory deficit) and 5 had complex syndromes. Three new deficits were anticipated with intraoperative neuromonitoring changes (p = 0.025).Three (50.0%) patients with new neurological deficits recovered within 6 months and the child with quadriparesis was regaining neurological function at the latest follow-up. Hemiplegia persisted in 1 patient, and 1 child died due a complication related to the tracheostomy. No association was found between neurological deficits and indication (p = 0.96), etiology (p = 0.46), preoperative neurological symptoms (p = 0.65), age (p = 0.56), use of halo vest (p = 0.41), estimated blood loss (p = 0.09), levels fused (p = 0.09), approach (p = 0.07), or fusion location (p = 0.07).

CONCLUSIONS

An improvement of the preexisting neurological deficit or stabilization of neurological function was seen in 96.7% of children after cervical spine fusion. New or progressive neurological deficits occurred in 3.3% of the patients and occurred more frequently in children with preoperative neurological symptoms. Patients with syndromic diagnoses are at higher risk to develop a deficit, probably due to the severity of deformity and the degree of cervical instability. Long-term outcomes of new neurological deficits are favorable, and 50% of patients experienced complete neurological recovery within 6 months.

Development of a postoperative ileus risk assessment scale: identification of intraoperative opioid exposure as a significant predictor after spinal surgery

OBJECTIVE

Postoperative ileus (POI) is associated with abdominal pain, nausea, vomiting, and delayed mobilization that in turn lead to diminished patient satisfaction, increased hospital length of stay (LOS), and increased healthcare costs. In this study, the authors developed a risk assessment scale to predict the likelihood of developing POI following spinal surgery.

METHODS

The authors undertook a retrospective review of a prospectively maintained registry of consecutive patients who underwent arthrodesis/fusion surgeries between May 2013 and December 2017. They extracted clinical information, including cumulative intraoperative and postoperative opioid doses using standardized converted morphine milligram equivalent (MME) values. Univariate and multivariate analyses were performed and several categorical and continuous variables were evaluated in a binary logistic regression model built with backward elimination to assess for independent predictors. A points-based prediction model was developed and validated to determine the risk of POI.

RESULTS

A total of 334 patients who underwent spinal fusion surgeries were included. Fifty-six patients (16.8%) developed POI, more frequently in those who underwent long-segment surgeries compared to short-segment surgeries (33.3% vs 10.4%; p < 0.001). POI was associated with an increased LOS when compared with patients who did not develop POI (8.0 ± 4.5 days vs 4.4 ± 2.4 days; p < 0.01). The incidences of liver disease (16% vs 3.7%; p = 0.01) and substance abuse history (12.0% vs 3.2%; p = 0.04) were higher in POI patients than non-POI patients undergoing short-segment surgeries. While the incidences of preoperative opioid intake (p = 0.23) and cumulative 24-hour (87.7 MME vs 73.2 MME; p = 0.08) and 72-hour (225.6 MME vs 221.4 MME; p = 0.87) postoperative opioid administration were not different, remifentanil (3059.3 µg vs 1821.5 µg; p < 0.01) and overall intraoperative opioid (326.7 MME vs 201.7 MME; p < 0.01) dosing were increased in the POI group. The authors derived a multivariate model based on the 5 most significant factors predictive of POI (number of surgical levels, intraoperative MME, liver disease, age, and history of substance abuse) and calculated relative POI risks using a derived 32-point system.

CONCLUSIONS

Intraoperative opioid administration, incorporated in a comprehensive risk assessment scale, represents an early and potentially modifiable predictor of POI. These data indicate that potential preventive strategies, implemented as part of enhanced recovery after surgery protocols, could be instituted in the preoperative phase of care to reduce POI incidence.

Surgical management of giant presacral schwannoma: systematic review of published cases and meta-analysis

OBJECTIVE

Giant presacral schwannomas are rare sacral tumors found in less than 1 of every 40,000 hospitalizations. Current management of these tumors is based solely upon case reports and small case series. In this paper the authors report the results of a systematic review of the available English literature on presacral schwannoma, focused on identifying the influence of tumor size, tumor morphology, surgical approach, and extent of resection (EOR) on recurrence-free survival and postoperative complications.

METHODS

The medical literature (PubMed and EMBASE) was queried for reports of surgically managed sacral schwannoma, either involving 2 or more contiguous vertebral levels or with a diameter ≥ 5 cm. Tumor size and morphology, surgical approach, EOR, intraoperative and postoperative complications, and survival data were recorded.

RESULTS

Seventy-six articles were included, covering 123 unique patients (mean age 44.1 ± 1.4 years, 50.4% male). The most common presenting symptoms were leg pain (28.7%), lower back pain (21.3%), and constipation (15.7%). Most surgeries used an open anterior-only (40.0%) or posterior-only (30%) approach. Postoperative complications occurred in 25.6% of patients and local recurrence was noted in 5.4%. En bloc resection significantly improved progression-free survival relative to subtotal resection (p = 0.03). No difference existed between en bloc and gross-total resection (GTR; p = 0.25) or among the surgical approaches (p = 0.66). Postoperative complications were more common following anterior versus posterior approaches (p = 0.04). Surgical blood loss was significantly correlated with operative duration and tumor volume on multiple linear regression (both p < 0.001).

CONCLUSIONS

Presacral schwannoma can reasonably be treated with either en bloc or piecemeal GTR. The approach should be dictated by lesion morphology, and recurrence is infrequent. Anterior approaches may increase the risk of postoperative complications.

Development and validation of risk stratification models for adult spinal deformity surgery

OBJECTIVE

Adult spinal deformity (ASD) surgery has a high rate of major complications (MCs). Public information about adverse outcomes is currently limited to registry average estimates. The object of this study was to assess the incidence of adverse events after ASD surgery, and to develop and validate a prognostic tool for the time-to-event risk of MC, hospital readmission (RA), and unplanned reoperation (RO).

METHODS

Two models per outcome, created with a random survival forest algorithm, were trained in an 80% random split and tested in the remaining 20%. Two independent prospective multicenter ASD databases, originating from the European continent and the United States, were queried, merged, and analyzed. ASD patients surgically treated by 57 surgeons at 23 sites in 5 countries in the period from 2008 to 2016 were included in the analysis.

RESULTS

The final sample consisted of 1612 ASD patients: mean (standard deviation) age 56.7 (17.4) years, 76.6% women, 10.4 (4.3) fused vertebral levels, 55.1% of patients with pelvic fixation, 2047.9 observation-years. Kaplan-Meier estimates showed that 12.1% of patients had at least one MC at 10 days after surgery; 21.5%, at 90 days; and 36%, at 2 years. Discrimination, measured as the concordance statistic, was up to 71.7% (95% CI 68%-75%) in the development sample for the postoperative complications model. Surgical invasiveness, age, magnitude of deformity, and frailty were the strongest predictors of MCs. Individual cumulative risk estimates at 2 years ranged from 3.9% to 74.1% for MCs, from 3.17% to 44.2% for RAs, and from 2.67% to 51.9% for ROs.

CONCLUSIONS

The creation of accurate prognostic models for the occurrence and timing of MCs, RAs, and ROs following ASD surgery is possible. The presented variability in patient risk profiles alongside the discrimination and calibration of the models highlights the potential benefits of obtaining time-to-event risk estimates for patients and clinicians.

Surgical correction of severe adult lumbar scoliosis (major curves ≥ 75°): retrospective analysis with minimum 2-year follow-up

OBJECTIVE

Prior reports have demonstrated the efficacy of surgical correction for adult lumbar scoliosis. Many of these reports focused on mild to moderate scoliosis. The authors' objective was to report their experience and to assess outcomes and complications after deformity correction for severe adult scoliosis.

METHODS

The authors retrospectively analyzed consecutive adult scoliosis patients with major thoracolumbar/lumbar (TL/L) curves ≥ 75° who underwent deformity correction at their institution. Those eligible with a minimum 2 years of follow-up were included. Demographic, surgical, coronal and sagittal plane radiographic measurements, and health-related quality of life (HRQL) scores were analyzed.

RESULTS

Among 26 potentially eligible patients, 22 (85%) had a minimum 2 years of follow-up (range 24-89 months) and were included in the study (mean age 57 ± 11 years; 91% women). The cohort comprised 16 (73%), 4 (18%), and 2 (9%) patients with adult idiopathic scoliosis, de novo degenerative scoliosis, and iatrogenic scoliosis, respectively. The surgical approach was posterior-only and multistage anterior-posterior in 18 (82%) and 4 (18%) patients, respectively. Three-column osteotomy was performed in 5 (23%) patients. Transforaminal and anterior lumbar interbody fusion were performed in 14 (64%) and 4 (18%) patients, respectively. All patients had sacropelvic fixation with uppermost instrumented vertebra in the lower thoracic spine (46% [10/22]) versus upper thoracic spine (55% [12/22]). The mean fusion length was 14 ± 3 levels. Preoperative major TL/L and lumbosacral fractional (L4-S1) curves were corrected from 83° ± 8° to 28° ± 13° (p < 0.001) and 34° ± 8° to 13° ± 6° (p < 0.001), respectively. Global coronal and sagittal balance significantly improved from 5 ± 4 cm to 1 ± 1 cm (p = 0.001) and 9 ± 8 cm to 2 ± 3 cm (p < 0.001), respectively. Pelvic tilt significantly improved from 33° ± 9° to 23° ± 10° (p < 0.001). Significant improvement in HRQL measures included the following: Scoliosis Research Society (SRS) pain score (p = 0.009), SRS appearance score (p = 0.004), and SF-12/SF-36 physical component summary (PCS) score (p = 0.026). Transient and persistent neurological deficits occurred in 8 (36%) and 2 (9%) patients, respectively. Rod fracture/pseudarthrosis occurred in 6 (27%) patients (supplemental rods were utilized more recently in 23%). Revisions were performed in 7 (32%) patients.

CONCLUSIONS

In this single-center surgical series for severe adult scoliosis (major curves ≥ 75°), a posterior-only or multistage anterior-posterior approach provided major curve correction of 66% and significant improvements in global coronal and sagittal spinopelvic alignment. Significant improvements were also demonstrated in HRQL measures (SRS pain, SRS appearance, and SF-12/SF-36 PCS). Complications and revisions were comparable to those of other reports involving less severe scoliosis. The results of this study warrant future prospective multicenter studies to further delineate outcomes and complication risks for severe adult scoliosis correction.

Reduction and monosegmental fusion for lumbar spondylolisthesis with a long tab percutaneous pedicle screw system: "swing" technique

OBJECTIVEWith the development of minimally invasive procedures, percutaneous pedicle screw systems have been used to attempt to correct spondylolisthesis. No previous studies have reported on reduction measures using long tab percutaneous pedicle screws for spondylolisthesis. Additional intraoperative correction has been proposed with the "swing" technique. This study was conducted to compare the efficacy of standard minimally invasive transforaminal interbody fusion (MIS-TLIF) with the efficacy of MIS-TLIF with the "swing" technique (MIS-TLIF and swing) in lumbar spondylolisthesis.METHODSThis was a matched-control study and included 30 consecutive patients who were followed up for 6 months after surgery. Of those patients, 15 were treated with operative reduction via MIS-TLIF with the "swing" technique, whereas the other 15 were treated with the standard MIS-TLIF procedure. The swing technique is a new reduction procedure for use with long tab percutaneous screws. In the swing technique, the entire system is swung back and forth several times after all constructs are placed. Only patients with Meyerding grade I or II lumbar spondylolisthesis were included in the study (18 with grade I and 12 with grade II). Perioperative and clinical outcomes, radiological parameters (Meyerding grade, percentage of slip, slip correction rate, segmental lordosis, and lumbar lordosis) were compared between groups at 6 months after surgery.RESULTSDemographic data did not differ significantly between the 2 groups. Postoperative clinical outcomes showed significant improvement in both groups. Postoperative radiological parameters showed that the degree of spondylolisthesis (swing: 4.7% vs standard: 8.9%) and reduction rate (swing: 77.3% vs standard: 57.1%) favored the swing group. The swing technique effectively decreased the degree of spondylolisthesis (swing: 24.1% to 4.7% vs standard: 21.8% to 8.9%). No complications related to the procedure were reported.CONCLUSIONSMIS-TLIF with the "swing" technique with long tab percutaneous pedicle screws is a safe and effective reduction method for monosegmental spondylolisthesis. This technique cannot only alleviate symptoms but also achieve nearly completely reduction of slippage.

Decompression of lumbar canal stenosis with a bilateral interlaminar versus classic laminectomy technique: a prospective randomized study

OBJECTIVEThe aim of this study was to compare the radiological and clinical results of bilateral interlaminar canal decompression and classic laminectomy in lumbar canal stenosis (LCS).METHODSTwo hundred eighteen patients with LCS were randomized to surgical treatment with classic laminectomy (group 1) or bilateral interlaminar canal decompression (group 2). Low-back and leg pain were evaluated according to the visual analog scale (VAS) both preoperatively and postoperatively. Disability was evaluated according to the Oswestry Disability Index (ODI) preoperatively and at 1 month, 1 year, and 3 years postoperatively. Neurogenic claudication was evaluated using the Zurich Claudication Questionnaire (ZCQ) preoperatively and 1 year postoperatively. The two treatment groups were compared in terms of neurogenic claudication, estimated blood loss (EBL), and intra- and postoperative complications.RESULTSPostoperative low-back and leg pain declined as compared to the preoperative pain. Both groups had significant improvement in VAS, ODI, and ZCQ scores, and the improvements in ODI and back pain VAS scores were significantly better in group 2. The average EBL was 140 ml in group 2 compared to 260 ml in group 1. Nine patients in the laminectomy group developed postoperative instability requiring fusion compared to only 4 cases in the interlaminar group (p = 0.15). Complications frequency did not show any statistical significance between the two groups.CONCLUSIONSBilateral interlaminar decompression is an effective method that provides sufficient canal decompression with decreased instability in cases of LCS and increases patient comfort in the postoperative period.

Outpatient and inpatient readmission rates of 3- and 4-level anterior cervical discectomy and fusion surgeries

OBJECTIVE

With the costs related to the United States medical system constantly rising, efforts are being made to turn traditional inpatient procedures into outpatient same-day surgeries. In this study the authors looked at the various comorbidities and perioperative complications and their impact on readmission rates of patients undergoing outpatient versus inpatient 3- and 4-level anterior cervical discectomy and fusion (ACDF).

METHODS

This was a retrospective study of 337 3- and 4- level ACDF procedures in 332 patients (5 patients had both primary and revision surgeries that were included in this total of 337 procedures) between May 2012 and June 2017. In total, 331 procedures were analyzed, as 6 patients were lost to follow-up. Outpatient surgery was performed for 299 procedures (102 4-level procedures and 197 3-level procedures), and inpatient surgery was performed for 32 procedures (11 4-level procedures and 21 3-level procedures). Age, sex, comorbidities, number of fusion levels, pain level, and perioperative complications were compared between both cohorts.

RESULTS

Analysis was performed for 331 3- and 4-level ACDF procedures done at 6 different hospitals. The overall 30-day readmission rate was 1.2% (outpatient 3 [1.0%] vs inpatient 1 [3.1%], p = 0.847). Outpatients had increased readmission risk, with comorbidities of coronary artery disease (OR 1.058, p = 0.039), autoimmune disease (OR 1.142, p = 0.006), diabetes (OR 1.056, p = 0.001), and chronic kidney disease (OR 0.933, p = 0.035). Perioperative complications of delirium (OR 2.709, p < 0.001) and surgical site infection (OR 2.709, p < 0.001) were associated with increased risk of 30-day hospital readmission in outpatients compared to inpatients.

CONCLUSIONS

This study demonstrates the safety and effectiveness of 3- and 4-level ACDF surgery, although various comorbidities and perioperative complications may lead to higher readmission rates. Patient selection for outpatient 3- and 4-level ACDF cases might play a role in the safety of performing these procedures in the ambulatory setting, but further studies are needed to accurately identify which factors are most pertinent for appropriate selection.

Diagnostic and therapeutic values of intraoperative electrophysiological neuromonitoring during resection of intradural extramedullary spinal tumors: a single-center retrospective cohort and meta-analysis

OBJECTIVEWith the advent of intraoperative electrophysiological neuromonitoring (IONM), surgical outcomes of various neurosurgical pathologies, such as brain tumors and spinal deformities, have improved. However, its diagnostic and therapeutic value in resecting intradural extramedullary (ID-EM) spinal tumors has not been well documented in the literature. The objective of this study was to summarize the clinical results of IONM in patients with ID-EM spinal tumors.METHODSA retrospective patient database review identified 103 patients with ID-EM spinal tumors who underwent tumor resection with IONM (motor evoked potentials, somatosensory evoked potentials, and free-running electromyography) from January 2010 to December 2015. Patients were classified as those without any new neurological deficits at the 6-month follow-up (group A; n = 86) and those with new deficits (group B; n = 17). Baseline characteristics, clinical outcomes, and IONM findings were collected and statistically analyzed. In addition, a meta-analysis in compliance with the PRISMA guidelines was performed to estimate the overall pooled diagnostic accuracy of IONM in ID-EM spinal tumor resection.RESULTSNo intergroup differences were discovered between the groups regarding baseline characteristics and operative data. In multivariate analysis, significant IONM changes (p < 0.001) and tumor location (thoracic vs others, p = 0.018) were associated with new neurological deficits at the 6-month follow-up. In predicting these changes, IONM yielded a sensitivity of 82.4% (14/17), specificity of 90.7% (78/86), positive predictive value (PPV) of 63.6% (14/22), negative predictive value (NPV) of 96.3% (78/81), and area under the curve (AUC) of 0.893. The diagnostic value slightly decreased in patients with schwannomas (AUC = 0.875) and thoracic tumors (AUC = 0.842). Among 81 patients who did not demonstrate significant IONM changes at the end of surgery, 19 patients (23.5%) exhibited temporary intraoperative exacerbation of IONM signals, which were recovered by interruption of surgical maneuvers; none of these patients developed new neurological deficits postoperatively. Including the present study, 5 articles encompassing 323 patients were eligible for this meta-analysis, and the overall pooled diagnostic value of IONM was a sensitivity of 77.9%, a specificity of 91.1%, PPV of 56.7%, and NPV of 95.7%.CONCLUSIONSIONM for the resection of ID-EM spinal tumors is a reasonable modality to predict new postoperative neurological deficits at the 6-month follow-up. Future prospective studies are warranted to further elucidate its diagnostic and therapeutic utility.

Impact of decompression surgery without fusion for lumbar spinal stenosis on sagittal spinopelvic alignment: minimum 2-year follow-up

OBJECTIVEThe importance of global sagittal alignment is well known. Patients with lumbar spinal stenosis (LSS) generally tend to bend forward to relieve their neurological symptoms, i.e., they have a positive sagittal vertical axis (SVA). We hypothesized that the positive SVA associated with LSS is symptom related and should improve after surgery. However, little is known about the changes in sagittal alignment in LSS patients after decompression surgery. In this study the authors aimed to evaluate midterm radiographical changes in sagittal spinopelvic alignment after decompression surgery for LSS and to determine the factors influencing the improvement in sagittal spinopelvic alignment.METHODSThe authors retrospectively reviewed 89 patients who underwent lumbar decompression without fusion between January 2014 and September 2015 with a minimum follow-up of 2 years. Standing whole-spine radiographs at the preoperative stage and at the final follow-up were examined. We analyzed SVA, lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), thoracolumbar kyphosis (TLK), and thoracic kyphosis (TK).RESULTSLL and TK were significantly increased postoperatively. SVA and PI minus LL (PI-LL) were significantly decreased. There were no significant differences between the preoperative and postoperative PT, PI, SS, or TLK. Twenty-nine patients had preoperative sagittal malalignment with SVA > 50 mm. Thirteen of the 29 patients improved to SVA < 50 mm after decompression surgery. Lower ASA grade, preoperative higher LL, and lower PI-LL were related to patient improvement. A receiver operating characteristic curve for the preoperative PI-LL had an area under the curve value of 0.821, indicating moderate accuracy (p = 0.003). A cutoff value for preoperative PI-LL of 19.2° showed a sensitivity of 93.5% and a specificity of 71.4%.CONCLUSIONSLumbar decompression can lead to a reactive improvement in the lumbar and global sagittal alignment. However, some of the sagittal malalignment in LSS was irreversible. Preoperative PI-LL was a useful predictor to distinguish reversible from irreversible sagittal malalignment.

Impact of total propofol dose during spinal surgery: anesthetic fade on transcranial motor evoked potentials

OBJECTIVEIntraoperative neuromonitoring may be valuable for predicting postoperative neurological complications, and transcranial motor evoked potentials (TcMEPs) are the most reliable monitoring modality with high sensitivity. One of the most frequent problems of TcMEP monitoring is the high rate of false-positive alerts, also called "anesthetic fade." The purpose of this study was to clarify the risk factors for false-positive TcMEP alerts and to find ways to reduce false-positive rates.METHODSThe authors analyzed 703 patients who underwent TcMEP monitoring under total intravenous anesthesia during spinal surgery within a 7-year interval. They defined an alert point as final TcMEP amplitudes ≤ 30% of the baseline. Variations in body temperature (maximum - minimum body temperature during surgery) were measured. Patients with false-positive alerts were classified into 2 groups: a global group with alerts observed in 2 or more muscles of the upper and lower extremities, and a focal group with alerts observed in 1 muscle.RESULTSFalse-positive alerts occurred in 100 cases (14%), comprising 60 cases with global and 40 cases with focal alerts. Compared with the 545 true-negative cases, in the false-positive cases the patients had received a significantly higher total propofol dose (1915 mg vs 1380 mg; p < 0.001). In the false-positive cases with global alerts, the patients had also received a higher mean propofol dose than those with focal alerts (4.5 mg/kg/hr vs 4.2 mg/kg/hr; p = 0.087). The cutoff value of the total propofol dose for predicting false-positive alerts, with the best sensitivity and specificity, was 1550 mg. Multivariate logistic analysis revealed that a total propofol dose > 1550 mg (OR 4.583; 95% CI 2.785-7.539; p < 0.001), variation in body temperature (1°C difference; OR 1.691; 95% CI 1.060-2.465; p < 0.01), and estimated blood loss (500-ml difference; OR 1.309; 95% CI 1.155-1.484; p < 0.001) were independently associated with false-positive alerts.CONCLUSIONSIntraoperative total propofol dose > 1550 mg, larger variation in body temperature, and greater blood loss are independently associated with false-positive alerts during spinal surgery. The authors believe that these factors may contribute to the false-positive global alerts that characterize anesthetic fade. As it is necessary to consider multiple confounding factors to distinguish false-positive alerts from true-positive alerts, including variation in body temperature or ischemic condition, the authors argue the importance of a team approach that includes surgeons, anesthesiologists, and medical engineers.

Impact of sagittal spinopelvic alignment on clinical outcomes and health-related quality of life after decompression surgery without fusion for lumbar spinal stenosis

OBJECTIVEPatients with lumbar spinal stenosis (LSS) tend to bend forward to relieve neurological symptoms. They therefore have a positive sagittal vertical axis (SVA). The importance of the SVA value is well known in the field of adult spinal deformity; however, little is known about its impact on LSS. The authors sought to investigate the impact of sagittal spinopelvic alignment on clinical outcome and health-related quality of life (HRQOL) after decompression surgery for LSS.METHODSThe authors retrospectively reviewed 83 patients who underwent lumbar decompression without fusion between January 2014 and September 2015 with a minimum follow-up of 2 years. Standing whole-spine radiographs were examined preoperatively and at final follow-up. Based on the SVA, patients were allocated to a sagittal balance group (group B; SVA < 50 mm) or a sagittal imbalance group (group I; SVA ≥ 50 mm). The authors compared the groups using Japanese Orthopaedic Association (JOA), Zurich Claudication Questionnaire (ZCQ), Roland-Morris Disability Questionnaire (RMDQ), and the 8-item Short Form Health Survey (SF-8) scores.RESULTSPreoperative groups B (group pre-B) and I (group pre-I) included 58 and 25 patients, respectively. Preoperative sagittal malalignment had negative effects on the JOA score recovery rate, postoperative ZCQ physical function domain score, and numeric rating scale (NRS) score of postoperative low-back pain (LBP), but no significant effects were observed for RMDQ and SF-8 domain scores. Postoperatively, groups B (group post-B) and I (group post-I) included 60 and 23 patients, respectively. Group post-I had a significantly worse JOA score recovery rate, postoperative symptom severity domain score in the ZCQ, and NRS score for postoperative LBP. Similarly, the postoperative RMDQ score and the Physical Component Summary score of the SF-8 were significantly worse in group post-I.CONCLUSIONSPositive SVA had significantly negative effects on clinical outcome and HRQOL in LSS patients after lumbar decompression surgery.

Rate of instrumentation changes on postoperative and follow-up radiographs after primary complex spinal fusion (five or more levels) for adult deformity correction

OBJECTIVEIn the United States, healthcare expenditures have been soaring at a concerning rate. There has been an excessive use of postoperative radiographs after spine surgery and this has been a target for hospitals to reduce unnecessary costs. However, there are only limited data identifying the rate of instrumentation changes on radiographs after complex spine surgery involving ≥ 5-level fusions.METHODSThe medical records of 136 adult (≥ 18 years old) patients with spine deformity undergoing elective, primary complex spinal fusion (≥ 5 levels) for deformity correction at a major academic institution between 2010 and 2015 were reviewed. Patient demographics, comorbidities, and intra- and postoperative complication rates were collected for each patient. The authors reviewed the first 5 subsequent postoperative and follow-up radiographs, and determined whether revision of surgery was performed within 5 years postoperatively. The primary outcome investigated in this study was the rate of hardware changes on follow-up radiographs.RESULTSThe majority of patients were female, with a mean age of 53.8 ± 20.0 years and a body mass index of 27.3 ± 6.2 kg/m2 (parametric data are expressed as the mean ± SD). The median number of fusion levels was 9 (interquartile range 7-13), with a mean length of surgery of 327.8 ± 124.7 minutes and an estimated blood loss of 1312.1 ± 1269.2 ml. The mean length of hospital stay was 6.6 ± 3.9 days, with a 30-day readmission rate of 14.0%. Postoperative and follow-up change in stability on radiographs (days from operation) included: image 1 (4.6 ± 9.3 days) 0.0%; image 2 (51.7 ± 49.9 days) 3.0%; image 3 (142.1 ± 179.8 days) 5.6%; image 4 (277.3 ± 272.5 days) 11.3%; and image 5 (463.1 ± 525.9 days) 15.7%. The 3rd year after surgery had the highest rate of hardware revision (5.55%), followed by the 2nd year (4.68%), and the 1st year (4.54%).CONCLUSIONSThis study suggests that the rate of instrumentation changes on radiographs increases over time, with no changes occurring at the first postoperative image. In an era of cost-conscious healthcare, fewer orders for early radiographs after complex spinal fusions (≥ 5 levels) may not impact patient care and can reduce the overall use of healthcare resources.

Incidental durotomy in the pediatric spine population

OBJECTIVESpine surgery is less common in children than adults. These surgeries, like all others, are subject to complications such as bleeding, infection, and CSF leak. The rate of incidental durotomy in the pediatric population, and its associated complications, has scarcely been reported in the literature.METHODSThis is a retrospective chart review of all pediatric patients operated on at Wake Forest Baptist Health from 2012 to 2017 who underwent spine surgeries. The authors excluded any procedures with intended durotomy, such as tethered cord release or spinal cord tumor resection.RESULTSFrom 2012 to 2017, 318 pediatric patients underwent surgery for a variety of indications, including adolescent idiopathic scoliosis (51.9%), neuromuscular scoliosis (27.4%), thoracolumbar fracture (2.83%), and other non-fusion-related indications (3.77%). Of these patients, the average age was 14.1 years, and 71.0% were female. There were 6 total incidental durotomies, resulting in an overall incidence of 1.9%. The incidence was 18.5% in revision operations, compared to 0.34% for index surgeries. Comparison of the revision cohort to the durotomy cohort revealed a trend toward increased length of stay, operative time, and blood loss; however, the trends were not statistically significant. The pedicle probe was implicated in 3 cases and the exact cause was not ascertained in the remaining 3 cases. The 3 durotomies caused by pedicle probe were treated with bone wax; 1 was treated with dry Gelfoam application and 2 were treated with primary repair. Only 1 patient had a persistent leak postoperatively that eventually required wound revision.CONCLUSIONSIncidental durotomy is an uncommon occurrence in the pediatric spinal surgery population. The majority occurred during placement of pedicle screws, and they were easily treated with bone wax at the time of surgery. Awareness of the incidence, predisposing factors, and treatment options is important in preventing complications and disability.

Factors associated with venous thromboembolic events following ICU admission in patients undergoing spinal surgery: an analysis of 1269 consecutive patients

In BriefIn a retrospective study the authors examined 1269 patients who underwent spinal surgery and were admitted to the intensive care unit (ICU) and identified factors that are associated with venous thromboembolic events (VTEs) in this "high risk" group. Amongst these high-risk factors were: surgeries longer than 4 hours, comorbid disease, patients needing an osteotomy, and patients undergoing spinal stabilization for fractures. Identification of factors that can be optimized prior to surgery will decrease the rates of VTE.

A systematic review of endoscopic versus open treatment of craniosynostosis. Part 2: the nonsagittal single sutures

OBJECTIVE

Despite increasing adoption of endoscopic techniques for repair of nonsagittal single-suture craniosynostosis, the efficacy and safety of the procedure relative to established open approaches are unknown. In this systematic review the authors aimed to directly compare open surgical and endoscope-assisted techniques for the treatment of metopic, unilateral coronal, and lambdoid craniosynostosis, with an emphasis on quantitative reported outcomes.

METHODS

A literature search was performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant articles were identified from 3 electronic databases (MEDLINE, EMBASE, and CENTRAL [Cochrane Central Register of Controlled Trials]) from their inception to August 2017. The quality of methodology and bias risk were assessed using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool for Quantitative Studies.

RESULTS

Of 316 screened records, 7 studies were included in a qualitative synthesis of the evidence, of which none were eligible for meta-analysis. These reported on 111 unique patients with metopic, 65 with unilateral coronal, and 12 with lambdoid craniosynostosis. For all suture types, 100 (53%) children underwent endoscope-assisted craniosynostosis surgery and 32 (47%) patients underwent open repair. These studies all suggest that blood loss, transfusion rate, operating time, and length of hospital stay were superior for endoscopically treated children. Although potentially comparable or better cosmetic outcomes are reported, the paucity of evidence and considerable variability in outcomes preclude meaningful conclusions.

CONCLUSIONS

Limited data comparing open and endoscopic treatments for metopic, unilateral coronal, and lambdoid synostosis suggest a benefit for endoscopic techniques with respect to blood loss, transfusion, length of stay, and operating time. This report highlights shortcomings in evidence and gaps in knowledge regarding endoscopic repair of nonsagittal single-suture craniosynostosis, emphasizing the need for further matched-control studies.

Endoscopic surgery for nonsyndromic craniosynostosis: a 16-year single-center experience

OBJECTIVE

In this paper the authors review their 16-year single-institution consecutive patient experience in the endoscopic treatment of nonsyndromic craniosynostosis with an emphasis on careful review of any associated treatment-related complications and methods of complication avoidance, including preoperative planning, intraoperative management, and postoperative care and follow-up.

METHODS

A retrospective chart review was conducted on all patients undergoing endoscopic, minimally invasive surgery for nonsyndromic craniosynostosis at Rady Children's Hospital from 2000 to 2015. All patients were operated on by a single neurosurgeon in collaboration with two plastic and reconstructive surgeons as part of the institution's craniofacial team.

RESULTS

Two hundred thirty-five patients underwent minimally invasive endoscopic surgery for nonsyndromic craniosynostosis from 2000 to 2015. The median age at surgery was 3.8 months. The median operative and anesthesia times were 55 and 105 minutes, respectively. The median estimated blood loss (EBL) was 25 ml (median percentage EBL 4.2%). There were no identified episodes of air embolism or operative deaths. One patient suffered an intraoperative sagittal sinus injury, 2 patients underwent intraoperative conversion of planned endoscopic to open procedures, 1 patient experienced a dural tear, and 1 patient had an immediate reexploration for a developing subgaleal hematoma. Two hundred twenty-five patients (96%) were admitted directly to the standard surgical ward where the median length of stay was 1 day. Eight patients were admitted to the intensive care unit (ICU) postoperatively, 7 of whom had preexisting medical conditions that the team had identified preoperatively as necessitating a planned ICU admission. The 30-day readmission rate was 1.7% (4 patients), only 1 of whom had a diagnosis (surgical site infection) related to their initial admission. Average length of follow-up was 2.8 years (range < 1 year to 13.4 years). Six children (< 3%) had subsequent open procedures for perceived suboptimal aesthetic results, 4 of whom (> 66%) had either coronal or metopic craniosynostosis. No patient in this series either presented with or subsequently developed signs or symptoms of intracranial hypertension.

CONCLUSIONS

In this large single-center consecutive patient series in the endoscopic treatment of nonsyndromic craniosynostosis, significant complications were avoided, allowing for postoperative care for the vast majority of infants on a standard surgical ward. No deaths, catastrophic postoperative morbidity, or evidence of the development of symptomatic intracranial hypertension was observed.

Endoscopy-assisted early correction of single-suture metopic craniosynostosis: a 19-year experience

In BriefThe long-term results of treating infants with metopic craniosynostosis by using endoscopic, minimally invasive techniques are reported. The impetus arose from the lack of consistent and favorable outcomes associated with calvarial vault remodeling techniques and from the very traumatic and invasive nature of these procedures. The results presented show excellent and consistent long-term outcomes that are superior to traditional methods and are associated with minimal trauma, blood loss, and anesthetic exposure, and with short surgical times.

Efficacy of immediate replacement of cranial bone graft following drainage of intracranial empyema

OBJECTIVE Intracranial empyema is a life-threatening condition associated with a high mortality rate and residual deleterious neurological effects if not diagnosed and managed promptly. The authors present their institutional experience with immediate reimplantation of the craniotomy flap and clarify the success of this method in terms of cranial integrity, risk of recurrent infection, and need for secondary procedures. METHODS A retrospective analysis of patients admitted for management of intracranial empyema during a 19-year period (1997-2016) identified 33 patients who underwent emergency drainage and decompression with a follow-up duration longer than 6 months, 23 of whom received immediate bone replacement. Medical records were analyzed for demographic information, extent and location of the infection, bone flap size, fixation method, need for further operative intervention, and duration of intravenous antibiotics. RESULTS The mean patient age at surgery was 8.7 ± 5.7 years and the infections were largely secondary to sinusitis (52.8%), with the most common location being the frontal/temporal region (61.3%). Operative intervention involved removal of a total of 31 bone flaps with a mean surface area of 22.8 ± 26.9 cm². Nearly all (96.8%) of the bone flaps replaced at the time of the initial surgery were viable over the long term. Eighteen patients (78.3%) required a single craniotomy in conjunction with antibiotic therapy to address the infection, whereas the remaining 21.7% required more than 1 surgery. Partial bone flap resorption was noted in only 1 (3.2%) of the 31 successfully replaced bone flaps. This patient eventually had his bone flap removed and received a split-calvaria bone graft. Twenty-one patients (91.3%) received postoperative CT scans to evaluate bone integrity. The mean follow-up duration of the cohort was 43.9 ± 54.0 months. CONCLUSIONS The results of our investigation suggest that immediate replacement and stabilization of the bone flap after craniectomy for drainage of intracranial empyemas has a low risk of recurrent infection and is a safe and effective way to restore bone integrity in most patients.

Male sex may not be associated with worse outcomes in primary all-posterior adult spinal deformity surgery: a multicenter analysis

OBJECTIVE Adolescent spine deformity studies have shown that male patients require longer surgery and have greater estimated blood loss (EBL) and complications compared with female patients. No studies exist to support this relationship in adult spinal deformity (ASD). The purpose of this study was to investigate associations between sex and complications, deformity correction, and health-related quality of life (HRQOL) in patients with ASD. It was hypothesized that male ASD patients would have greater EBL, longer surgery, and more complications than female ASD patients. METHODS A multicenter ASD cohort was retrospectively queried for patients who underwent primary posterior-only instrumented fusions with a minimum of 5 levels fused. The minimum follow-up was 2 years. Primary outcomes were EBL, operative time, intra-, peri-, and postoperative complications, radiographic correction, and HRQOL outcomes (Oswestry Disability Index, SF-36, and Scoliosis Research Society-22r Questionnaire). Poisson multivariate regression was used to control for age, comorbidities, and levels fused. RESULTS Ninety male and 319 female patients met the inclusion criteria. Male patients had significantly greater mean EBL (2373 ml vs 1829 ml, p = 0.01). The mean operative time, transfusion requirements, and final radiographic measurements did not differ between sexes. Similarly, changes in HRQOL showed no significant differences. Finally, there were no sex differences in the incidence of complications (total, major, or minor) at any time point after controlling for age, body mass index, comorbidities, and levels fused. CONCLUSIONS Despite higher EBL, male ASD patients did not experience more complications or require less deformity correction at the 2-year follow-up. HRQOL scores similarly showed no sex differences. These findings differ from adolescent deformity studies, and surgeons can counsel patients that sex is unlikely to influence the outcomes and complication rates of primary all-posterior ASD surgery.

Chiari decompression outcomes using ligamentum nuchae harvest and duraplasty in pediatric patients with Chiari malformation type I

OBJECTIVE The choice of graft material for duraplasty in decompressions of Chiari malformations remains a matter of debate. The authors present a detailed technique for harvesting ligamenta nuchae, as well as the clinical and radiographic outcomes of this technique, in a case series. METHODS The authors conducted a retrospective study evaluating the outcomes of Chiari malformation type I decompression and duraplasty in children aged 0-18 years at a single institution from 2013 to 2016. They collected both intraoperative and postoperative variables and compared them qualitatively to published data. RESULTS During the study period, the authors performed 25 Chiari malformation decompressions with ligamentum nuchae graft duraplasties. Of the 25 patients, 10 were females, and the mean age at surgery was 8.6 years (range 13 months to 18 years). The median operative time was 163 minutes (IQR 152-187 minutes), with approximately 10 minutes needed by a resident surgeon to harvest the graft. The mean length of stay was 3 nights (range 2-6 nights), and the mean follow-up was 12.6 months (range 0.5-43.5 months). One patient (4%) developed a CSF leak that was repaired using an oversewing patch. There were no postoperative pseudomeningoceles or infections. Of the 19 patients presenting with a syrinx, imaging showed improvement in 10 (53%) and 8 (42%) had stable syrinx size on imaging. Of 16 patients presenting with a symptomatic Chiari malformation, 14 (87.5%) experienced resolution of symptoms and in 1 (4%) symptoms remained the same. One patient (4%) presented with worsening syrinx and symptoms 1.5 months after initial surgery and underwent repeat decompression. CONCLUSIONS The authors describe a series of clinical and imaging outcomes of patients who underwent Chiari malformation decompression and duraplasty with a harvested ligamentum nuchae. The rates of postoperative CSF leak are similar to established techniques of autologous and artificial grafts, with similarly successful outcomes. Further study will be needed with larger patient cohorts to more directly compare duraplasty graft outcomes.

The Meningioma Vascularity Index: a volumetric analysis of flow voids to predict intraoperative blood loss in nonembolized meningiomas

OBJECTIVEMeningiomas that appear hypervascular on neuroimaging could be amenable to preoperative embolization. However, methods for measuring hypervascularity have not been described, nor has the benefit of preoperative embolization been adjudicated. The objective of this study was to show a relationship between flow void volume (measured on MRI) and intraoperative estimated blood loss (EBL) in nonembolized meningiomas.METHODSThe authors performed volumetric analyses of 51 intracranial meningiomas (21 preoperatively embolized) resected at their institution. Through the use of image segmentation software and a voxel-based segmentation method, flow void volumes were measured on T2-weighted MR images. This metric was named the Meningioma Vascularity Index (MVI). The primary outcomes were intraoperative EBL and perioperative blood transfusion.RESULTSIn the nonembolized group, the MVI correlated with intraoperative EBL when controlling for tumor volume (r = 0.55, p = 0.002). The MVI also correlated with perioperative blood transfusion (point-biserial correlation [rpb] = 0.57, p = 0.001). A greater MVI was associated with an increased risk of blood transfusion (odds ratio [OR] 5.79, 95% confidence interval [CI] 1.15-29.15) and subtotal resection (OR 7.64, 95% CI 1.74-33.58). In the embolized group, those relationships were not found. There were no significant differences in MVI, intraoperative EBL, or blood transfusion across groups.CONCLUSIONSThis study clearly shows a relationship between MVI and intraoperative EBL in nonembolized meningiomas when controlling for tumor volume. The MVI is a potential biomarker for tumors that would benefit from embolization.

Tubular approach to minimally invasive microdiscectomy for pediatric lumbar disc herniation

OBJECTIVE Lumbar disc herniation (LDH) in the pediatric population is rare and exhibits unique characteristics compared with adult LDH. There are limited data regarding the safety and efficacy of minimally invasive surgery (MIS) using tubular retractors in pediatric patients with LDH. Here, the outcomes of MIS tubular microdiscectomy for the treatment of pediatric LDH are evaluated. METHODS Twelve consecutive pediatric patients with LDH were treated with MIS tubular microdiscectomy at the authors' institution between July 2011 and October 2015. Data were gathered from retrospective chart review and from mail or electronic questionnaires. The Macnab criteria and the Oswestry Disability Index (ODI) were used for outcome measurements. RESULTS The mean age at surgery was 17 ± 1.6 years (range 13-19 years). Seven patients were female (58%). Prior to surgical intervention, 100% of patients underwent conservative treatment, and 50% had epidural steroid injections. Preoperative low-back and leg pain, positive straight leg raise, and myotomal leg weakness were noted in 100%, 83%, and 67% of patients, respectively. The median duration of symptoms prior to surgery was 9 months (range 1-36 months). The LDH level was L5-S1 in 75% of patients and L4-5 in 25%. The mean ± SD operative time was 90 ± 21 minutes, the estimated blood loss was ≤ 25 ml in 92% of patients (maximum 50 ml), and no intraoperative or postoperative complications were noted at 30 days. The median hospital length of stay was 1 day (range 0-3 days). The median follow-up duration was 2.2 years (range 0-5.8 years). One patient experienced reherniation at 18 months after the initial operation and required a second same-level MIS tubular microdiscectomy to achieve resolution of symptoms. Of the 11 patients seen for follow-up, 10 patients (91%) reported excellent or good satisfaction according to the Macnab criteria at the last follow-up. Only 1 patient reported a fair level of satisfaction by using the same criteria. Seven patients completed an ODI evaluation at the last follow-up. For these 7 patients, the mean ODI low-back pain score was 19.7% (SEM 2.8%). CONCLUSIONS To the authors' knowledge, this is the longest outcomes study and the largest series of pediatric patients with LDH who were treated with MIS microdiscectomy using tubular retractors. These data suggest that MIS tubular microdiscectomy is safe and efficacious for pediatric LDH. Larger prospective cohort studies with longer follow-up are needed to better evaluate the long-term efficacy of MIS tubular microdiscectomy versus other open and MIS techniques for the treatment of pediatric LDH.