Unintended durotomy in lumbar degenerative spinal surgery: a 10-year systematic review of the literature

Lateral-PLIF for spinal arthrodesis: concept, technique, results, complications, and outcomes

BACKGROUND

Posterior lumbar interbody fusion (PLIF) surgery represents an effective option to treat degenerative conditions in the lumbar spine. To reduce the drawbacks of the classical technique, we developed a variant, so-called Lateral-PLIF, which we then evaluated through a prospective consecutive series of patients.

METHODS

All adult patients treated at our institute with single or double level Lateral-PLIF for lumbar degenerative disease from January to December 2017 were prospectively collected. Exclusion criteria were patients < 18 years of age, traumatic patients, active infection, or malignancy, as well as unavailability of clinical and/or radiological follow-up data. The technique consists of insert the cages bilaterally through the transition zone between the central canal and the intervertebral foramen, just above the lateral recess. Pre- and postoperative (2 years) questionnaires and phone interviews (4 years) assessed pain and functional outcomes. Data related to the surgical procedure, postoperative complications, and radiological findings (1 year) were collected.

RESULTS

One hundred four patients were selected for the final analysis. The median age was 58 years and primary symptoms were mechanical back pain (100, 96.1%) and/or radicular pain (73, 70.2%). We found a high fusion rate (95%). A statistically significant improvement in functional outcome was also noted (ODI p < 0.001, Roland-Morris score p < 0.001). Walking distance increased from 812 m ± 543 m to 3443 m ± 712 m (p < 0.001). Complications included dural tear (6.7%), infection/wound dehiscence (4.8%), and instrument failure (1.9%) but no neurological deterioration.

CONCLUSIONS

Lateral-PLIF is a safe and effective technique for lumbar interbody fusion and may be considered for further comparative study validation with other techniques before extensive use to treat lumbar degenerative disease.

Intraoperative and Postoperative Management of Incidental Durotomies During Open Degenerative Lumbar Spine Surgery: A Systematic Review

SUMMARY OF BACKGROUND DATA

Incidental durotomy is a common intraoperative complication of lumbar spine surgery. Intra and postoperative protocols in the management of this common complication vary considerably, with no consensus in the literature.

OBJECTIVE

To systematically review (1) lumbar dural repair techniques for open degenerative procedures; (2) review described postoperative protocols after lumbar dural repairs.

STUDY DESIGN

Systematic review.

MATERIALS AND METHODS

A systematic review of the literature was performed for all articles published from inception until September 2022 using Pubmed, EMBASE, Medline, and Cochrane databases to identify articles assessing the management of durotomy in open surgery for degenerative diseases of the lumbar spine. Two independent reviewers assessed the articles for inclusion criteria, and disagreements were resolved by consensus. Outcomes included persistent leaks, return to the operating room, recurrent symptoms, medical complications, or patient satisfaction.

RESULTS

A total of 10,227 articles were initially screened. After inclusion criteria were applied, 9 studies were included (n=1270 patients) for final review. Repair techniques included; no primary repair, suture repair in running or interrupted manner with or without adjunctive sealants, sealants alone, or patch repair with muscle, fat, epidural blood patch, or synthetic graft. Postoperative protocols included the placement of a subfascial drain with varying durations of bed rest. Notable findings included no benefit of prolonged bedrest compared with early ambulation ( P =0.4), reduced cerebrospinal fluid leakage with fat graft compared with muscle grafts ( P <0.001), and decreased rates of revision surgery in studies that used subfascial drains (1.7%-2.2% vs 4.34%-6.66%).

CONCLUSIONS

Significant variability in intraoperative durotomy repair techniques and postoperative protocols exists. Primary repair with fat graft augmentation seems to have the highest success rate. Postoperatively, the use of a subfascial drain with early ambulation reduces the risk of pseudomenignocele formation, medical complications, and return to the operating room. Further research should focus on prospective studies with the goal to standardize repair techniques and postoperative protocols.

The Predictors of Incidental Durotomy in Patients Undergoing Pedicle Subtraction Osteotomy for the Correction of Adult Spinal Deformity

Background: Pedicle subtraction osteotomy (PSO) is a powerful tool for sagittal plane correction in patients with rigid adult spinal deformity (ASD); however, it is associated with high intraoperative blood loss and the increased risk of durotomy. The objective of the present study was to identify intraoperative techniques and baseline patient factors capable of predicting intraoperative durotomy. Methods: A tri-institutional database was retrospectively queried for all patients who underwent PSO for ASD. Data on baseline comorbidities, surgical history, surgeon characteristics and intraoperative maneuvers were gathered. PSO aggressiveness was defined as conventional (Schwab 3 PSO) or an extended PSO (Schwab type 4). The primary outcome of the study was the occurrence of durotomy intraoperatively. Univariable analyses were performed with Mann-Whitney U tests, Chi-squared analyses, and Fisher's exact tests. Statistical significance was defined by p < 0.05. Results: One hundred and sixteen patients were identified (mean age 61.9 ± 12.6 yr; 44.8% male), of whom 51 (44.0%) experienced intraoperative durotomy. There were no significant differences in baseline comorbidities between those who did and did not experience durotomy, with the exception that baseline weight and body mass index were higher in patients who did not suffer durotomy. Prior surgery (OR 2.73; 95% CI [1.13, 6.58]; p = 0.03) and, more specifically, prior decompression at the PSO level (OR 4.23; 95% CI [1.92, 9.34]; p < 0.001) was predictive of durotomy. A comparison of surgeon training showed no statistically significant difference in durotomy rate between fellowship and non-fellowship trained surgeons, or between orthopedic surgeons and neurosurgeons. The PSO level, PSO aggressiveness, the presence of stenosis at the PSO level, nor the surgical instrument used predicted the odds of durotomy occurrence. Those experiencing durotomy had similar hospitalization durations, rates of reoperation and rates of nonroutine discharge. Conclusions: In this large multisite series, a history of prior decompression at the PSO level was associated with a four-fold increase in intraoperative durotomy risk. Notably the use of extended (versus) standard PSO, surgical technique, nor baseline patient characteristics predicted durotomy. Durotomies occurred in 44% of patients and may prolong operative times. Additional prospective investigations are merited.

Early ambulation versus prolonged bed rest for incidental durotomies in spine procedures: a systematic review and meta-analysis

Incidental durotomies are frequent complications of spine surgery associated with cerebrospinal fluid (CSF) leak-related symptoms. Management typically involves prolonged bed rest to reduce CSF pressure at the durotomy site. However, early ambulation may be a safer, effective alternative. PubMed, Web of Science, Embase, Cochrane, and Scopus were systematically searched for studies comparing early ambulation (bed rest ≤ 24 h) with prolonged bed rest (> 24 h) for patients with incidental durotomies in spine surgeries. The outcomes of interest were CSF leak, hypotensive headache, additional surgical repair, pseudomeningocele, and pulmonary complications. Systematic reviews and meta-analysis were performed following the Cochrane Handbook for Systematic Reviews of Interventions. We included a total of 704 patients from 6 studies. There was a significant reduction in the incidence of pulmonary complications (RR 0.23; 95% CI 0.08-0.67; p = 0.007) in the early mobilization group. The incidence of CSF leak (RR 1.34; 95% CI 0.83-2.14; p = 0.23), hypotensive headache (RR 0.72; 95% CI 0.27-1.90; p = 0.50), additional repair surgery (RR 1.29; 95% CI 0.76-2.2; p = 0.35), and pseudomeningocele (RR 1.29; 95% CI 0.20-8.48; p = 0.79) did not differ significantly. In patients with incidental durotomy following spinal surgery, early mobilization was associated with a lower incidence of pulmonary complications as compared with prolonged bed rest. There was no significant difference between groups in terms of CSF leak, need for additional repair, pseudomeningocele, and hypotensive headache.

Acetazolamide, Short Bed Rest, and Subfascial Off-Suction Drainage in Preventing Persistent Spinal Fluid Leaks from Incidental Dural Tears

BACKGROUND

 Postoperative cerebrospinal fluid (CSF) leak might occur after the repair of dural tears. Acetazolamide lowers intradural pressure by decreasing CSF production. The aim of this study was to investigate the incidence of persistent CSF leak from incidental dural tears after using acetazolamide, short bed rest, and subfascial off-suction drainage.

METHODS

 The medical records at the Ain Shams University hospital were examined retrospectively for this descriptive single-arm cohort study. Adult patients who underwent lumbar degenerative spine surgery from January 2011 through January 2021 were enrolled. The included patients experienced a CSF leak and were administered acetazolamide 1.5 g/d from postoperative day (POD) 1 to POD 7. Subfascial drainage was kept for a maximum of 5 days without suction.

RESULTS

 Seventy-four patients met the inclusion criteria of the study. Fifty-nine patients (79.7%) had recurrent lumbar surgery. The average age of the patients was 55.7 years. In all patients, the quantity of fluid in the drain decreased on a daily basis. The subfascial drain was kept for 5 days in 26 patients (35.1%). There was no wound infection, collection, or persistent CSF leakage in any of the patients over the 6-month follow-up period.

CONCLUSIONS

 In this study, acetazolamide was well tolerated by the patients and, in addition to short bed rest (72 hours) and off-suction subfascial drainage, did not result in persistent CSF leakage in any patient. A prospective placebo-controlled study is beneficial to confirm the efficacy of acetazolamide in preventing CSF leakage.

Outpatient minimally invasive spine surgeries during the COVID-19 pandemic - A retrospective analysis of 164 consecutive cases

Objective

To share our surgical experiences of minimally invasive cervical and lumbar procedures for patients who suffered from non-fatal motor vehicle accidents (MVAs) in the ambulatory surgery centers (ASCs) during the coronavirus disease 2019 (COVID-19) pandemic.

Methods

Anterior cervical discectomy and fusion (ACDF), anterior lumbar interbody fusion (ALIF), minimally invasive laminotomy and discectomy (MILD), percutaneous endoscopic laser-assisted discectomy (PELD) and percutaneous kyphoplasty (PK) were performed on carefully selected patients.

Results

From January 2020 to December 2021, our group performed 164 cases on 153 patients involving 249 intervertebral disc (IVD) levels. Of these, 116 cases (70.73%) on 114 patients (74.51%) were cervical, 48 cases (29.27%) were lumbar (including 8 PK cases). Eight patients had both cervical and lumbar procedures in a single anesthetic session (SAS) and were discharged on the same day. One hundred and six ACDF cases (92.17%) were at the C4-C5 and C5-C6 levels, which comprised of 146 (76.04%) IVDs. Of the 40 non-PK lumbar cases, 38 (95.0%) were at L4 to S1 lumbar levels. Six of these cases (15.0%) involved 2 lumbar levels. In contrast, 6 out of 8 kyphoplasties (75.0%) involved lower thoracic/higher lumbar vertebral columns (T11 to L2) and 2 were at the lower lumbar L4 level.

Conclusions

We successfully and safely performed various cervical and lumbar spine surgeries in the ASCs amid COVID-19 pandemic and all patients achieved the same-day discharge (SDD). In the non-fatal MVAs, mid-lower cervical (C4 to C6) and lower lumbar (L4 to S1) IVDs were the most affected levels.

Incidence, Risk Factors, and Outcomes of Incidental Durotomy during Lumbar Spine Decompression with or without Fusion

STUDY DESIGN

Retrospective cohort study.

PURPOSE

The primary objective of this study was to determine the incidence and risk factors for incidental durotomies during lumbar decompression surgeries. In addition, we aimed to determine the changes in patient-reported outcome measures (PROMs) based on incidental durotomy status.

OVERVIEW OF LITERATURE

There is limited literature investigating the affect of incidental durotomy on patient reported outcome measures. While the majority of research does not suggest differences in complications, readmission, or revision rates, many studies rely on public databases, and their sensitivity and specificity for identifying incidental durotomies is unknown.

METHODS

Patients undergoing lumbar decompression with or without fusion at a single tertiary care center were grouped based on the presence of a durotomy. Multivariate analysis was performed for length of stay (LOS), hospital readmissions, and changes in PROMs. To identify surgical risk factors for durotomy, 3:1 propensity matching was performed using stepwise logistic regression. The sensitivity and specificity of the International Classification of Disease, 10th revision (ICD-10) codes (G96.11 and G97.41) were also assessed.

RESULTS

Of the 3,684 consecutive patients who underwent lumbar decompressions, 533 (14.5%) had durotomies, and a complete set of PROMs (preoperative and 1-year postoperative) were available for 737 patients (20.0%). Incidental durotomy was an independent predictor of increased LOS but not hospital readmission or worse PROMs. The durotomy repair method was not associated with hospital readmission or LOS. However, repair with collagen graft and suture predicted reduced improvement in Visual Analog Scale back (β =2.56, p=0.004). Independent risk factors for incidental durotomies included revisions (odds ratio [OR], 1.73; p<0.001), levels decompressed (OR, 1.11; p=0.005), and preoperative diagnosis of spondylolisthesis or thoracolumbar kyphosis. The sensitivity and specificity of ICD-10 codes were 5.4% and 99.9%, respectively, for identifying durotomies.

CONCLUSIONS

The durotomy rate for lumbar decompressions was 14.5%. No differences in outcomes were detected except for increased LOS. Database studies relying on ICD codes should be interpreted with caution due to the limited sensitivity in identifying incidental durotomies.

Incidence and management of dural tears in full-endoscopic unilateral laminotomies for bilateral lumbar decompression

PURPOSE

To report incidence of dural lacerations in lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD) and to describe patient outcomes following a novel full-endoscopic bimanual durotomy repair.

METHODS

Retrospective review of prospectively collected database including 5.5 years of single surgeon experience with LE-ULBD. Patients with no durotomy were compared with patients who experienced intraoperative durotomy, including demographics, ASA score, prior surgery, number of levels treated, procedure time, hospital length of stay (LOS), visual analogue scale, perioperative complications, revision surgeries, use of analgesics, and Oswestry Disability Index (ODI).

RESULTS

In total, 13/174 patients (7.5%) undergoing LE-ULBD experienced intraoperative durotomy. No significant differences in demographic, clinical or operative variables were identified between the 2 groups. Sustaining a durotomy increased LOS (p = 0.0019); no differences in perioperative complications or rate of revision surgery were identified. There was no difference in minimally clinically important difference for ODI between groups (65.6% for no durotomy versus 55.6% for durotomy, p = 0.54).

CONCLUSION

In this cohort, sustaining a durotomy increased LOS but, with accompanying intraoperative repair, did not significantly affect rate of complications, revision surgery or functional outcomes. Our method of bimanual endoscopic dural repair provides an effective approach for repair of dural lacerations in interlaminar ULBD cases.

Dural injury following elective spine surgery - A prospective analysis of risk factors, management and complications

Incidental dural tears being a familiar complication in spine surgery could result in dreaded postoperative outcomes. Though the literature pertaining to their incidence and management is vast, it is limited by the retrospective study designs and smaller case series. Hence, we performed a prospective study in our institute to determine the incidence, surgical risk factors, complications and surgical outcomes in patients with unintended durotomy during spine surgery over a period of one year. The overall incidence in our study was 2.3% (44/1912). Revision spine surgeries in particular had a higher incidence of 16.6%. The average age of the study population was 51.6 years. The most common intraoperative surgical step associated with dural tear was removal of the lamina, and 50% of the injuries were during usage of kerrison rongeur. The most common location of the tear was paramedian location (20 patients) and the most common size of the tear was about 1 mm-5mm (31 patients). We observed that the dural repair techniques, placement of drain and prolonged post-operative bed rest didnot significantly affect the post-operative outcomes. One patient in our study developed persistent CSF leak, which was treated by subarachnoid lumbar drain placement. No patients developed pseudomeningocele or post-operative neurological worsening or re-exploration for dural repair. Wound complications were noted in 4 patients and treated by debridement and antibiotics. Based on our study, we have proposed a treatment algorithm for the management of dural tears in spine surgery.

Can We Geographically Validate a Natural Language Processing Algorithm for Automated Detection of Incidental Durotomy Across Three Independent Cohorts From Two Continents?

BACKGROUND

Incidental durotomy is an intraoperative complication in spine surgery that can lead to postoperative complications, increased length of stay, and higher healthcare costs. Natural language processing (NLP) is an artificial intelligence method that assists in understanding free-text notes that may be useful in the automated surveillance of adverse events in orthopaedic surgery. A previously developed NLP algorithm is highly accurate in the detection of incidental durotomy on internal validation and external validation in an independent cohort from the same country. External validation in a cohort with linguistic differences is required to assess the transportability of the developed algorithm, referred to geographical validation. Ideally, the performance of a prediction model, the NLP algorithm, is constant across geographic regions to ensure reproducibility and model validity.

QUESTION/PURPOSE

Can we geographically validate an NLP algorithm for the automated detection of incidental durotomy across three independent cohorts from two continents?

METHODS

Patients 18 years or older undergoing a primary procedure of (thoraco)lumbar spine surgery were included. In Massachusetts, between January 2000 and June 2018, 1000 patients were included from two academic and three community medical centers. In Maryland, between July 2016 and November 2018, 1279 patients were included from one academic center, and in Australia, between January 2010 and December 2019, 944 patients were included from one academic center. The authors retrospectively studied the free-text operative notes of included patients for the primary outcome that was defined as intraoperative durotomy. Incidental durotomy occurred in 9% (93 of 1000), 8% (108 of 1279), and 6% (58 of 944) of the patients, respectively, in the Massachusetts, Maryland, and Australia cohorts. No missing reports were observed. Three datasets (Massachusetts, Australian, and combined Massachusetts and Australian) were divided into training and holdout test sets in an 80:20 ratio. An extreme gradient boosting (an efficient and flexible tree-based algorithm) NLP algorithm was individually trained on each training set, and the performance of the three NLP algorithms (respectively American, Australian, and combined) was assessed by discrimination via area under the receiver operating characteristic curves (AUC-ROC; this measures the model's ability to distinguish patients who obtained the outcomes from those who did not), calibration metrics (which plot the predicted and the observed probabilities) and Brier score (a composite of discrimination and calibration). In addition, the sensitivity (true positives, recall), specificity (true negatives), positive predictive value (also known as precision), negative predictive value, F1-score (composite of precision and recall), positive likelihood ratio, and negative likelihood ratio were calculated.

RESULTS

The combined NLP algorithm (the combined Massachusetts and Australian data) achieved excellent performance on independent testing data from Australia (AUC-ROC 0.97 [95% confidence interval 0.87 to 0.99]), Massachusetts (AUC-ROC 0.99 [95% CI 0.80 to 0.99]) and Maryland (AUC-ROC 0.95 [95% CI 0.93 to 0.97]). The NLP developed based on the Massachusetts cohort had excellent performance in the Maryland cohort (AUC-ROC 0.97 [95% CI 0.95 to 0.99]) but worse performance in the Australian cohort (AUC-ROC 0.74 [95% CI 0.70 to 0.77]).

CONCLUSION

We demonstrated the clinical utility and reproducibility of an NLP algorithm with combined datasets retaining excellent performance in individual countries relative to algorithms developed in the same country alone for detection of incidental durotomy. Further multi-institutional, international collaborations can facilitate the creation of universal NLP algorithms that improve the quality and safety of orthopaedic surgery globally. The combined NLP algorithm has been incorporated into a freely accessible web application that can be found at https://sorg-apps.shinyapps.io/nlp_incidental_durotomy/ . Clinicians and researchers can use the tool to help incorporate the model in evaluating spine registries or quality and safety departments to automate detection of incidental durotomy and optimize prevention efforts.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Minimally invasive versus open lumbar spinal fusion: a matched study investigating patient-reported and surgical outcomes

OBJECTIVE

With the expanding indications for and increasing popularity of minimally invasive surgery (MIS) for lumbar spinal fusion, large-scale outcomes analysis to compare MIS approaches with open procedures is warranted.

METHODS

The authors queried the Quality Outcomes Database for patients who underwent elective lumbar fusion for degenerative spine disease. They performed optimal matching, at a 1:2 ratio between patients who underwent MIS and those who underwent open lumbar fusion, to create two highly homogeneous groups in terms of 33 baseline variables (including demographic characteristics, comorbidities, symptoms, patient-reported scores, indications, and operative details). The outcomes of interest were overall satisfaction, decrease in Oswestry Disability Index (ODI), and back and leg pain, as well as hospital length of stay (LOS), operative time, reoperations, and incidental durotomy rate. Satisfaction was defined as a score of 1 or 2 on the North American Spine Society scale. Minimal clinically important difference (MCID) in ODI was defined as ≥ 30% decrease from baseline. Outcomes were assessed at the 3- and 12-month follow-up evaluations.

RESULTS

After the groups were matched, the MIS and open groups consisted of 1483 and 2966 patients, respectively. Patients who underwent MIS fusion had higher odds of satisfaction at 3 months (OR 1.4, p = 0.004); no difference was demonstrated at 12 months (OR 1.04, p = 0.67). Lumbar stenosis, single-level fusion, higher American Society of Anesthesiologists Physical Status Classification System grade, and absence of spondylolisthesis were most prominently associated with higher odds of satisfaction with MIS compared with open surgery. Patients in the MIS group had slightly lower ODI scores at 3 months (mean difference 1.61, p = 0.006; MCID OR 1.14, p = 0.0495) and 12 months (mean difference 2.35, p < 0.001; MCID OR 1.29, p < 0.001). MIS was also associated with a greater decrease in leg and back pain at both follow-up time points. The two groups did not differ in operative time and incidental durotomy rate; however, LOS was shorter for the MIS group. Revision surgery at 12 months was less likely for patients who underwent MIS (4.1% vs 5.6%, p = 0.032).

CONCLUSIONS

In patients who underwent lumbar fusion for degenerative spinal disease, MIS was associated with higher odds of satisfaction at 3 months postoperatively. No difference was demonstrated at the 12-month follow-up. MIS maintained a small, yet consistent, superiority in decreasing ODI and back and leg pain, and MIS was associated with a lower reoperation rate.

Iliac Screw Fixation Revisited: Improved Clinical and Radiologic Outcomes Using a Modified Iliac Screw Fixation Technique

STUDY DESIGN

A retrospective study.

OBJECTIVE

To describe the modified iliac screw (mILS) technique and compare it to other spinopelvic fixation techniques in terms of wound healing complications, hardware prominence, and failure.

SUMMARY OF BACKGROUND DATA

The traditional entry point of an iliac screw often causes postoperative gluteal pain from the prominent screw head. The use of an offset connector also adds a point of weakness to the construct. By choosing a different screw entry point offset connectors can be avoided, and the screw head itself is less prominent, thereby reducing postoperative discomfort.

MATERIALS AND METHODS

A retrospective analysis was performed of adult patients undergoing lumbopelvic fixation (LPF) between January 2014 and June 2019. Patients were grouped into 1 of 3 groups based on the technique of pelvic fixation: S2 alar-iliac (S2AI) screw, traditional iliac screw (tILS), and mILS. The primary outcome parameter was the minimal distance from screw head to skin. Secondary outcome parameters were instrumentation loosening/failure, adjacent level fractures, pseudoarthrosis, and medial or lateral iliac screw perforation.

RESULTS

A total of 190 patients undergoing LPF were included in the following 3 groups: mILS group (n=113), tILS group (n=40), and S2AI group (n=37). The mean minimal distance from screw head to skin in the mILS group was 31.3 mm compared with 23.7 mm in the tILS group (P<0.00199). No statistically significant differences were found when comparing the 3 groups with respect to complications. The mILS group did not show any cases of prominent instrumentation and had the lowest rate of instrumentation failure.

CONCLUSIONS

The mILS technique is an acceptable alternative for LPF, offering the benefits of iliac screw fixation while avoiding offset connectors and screw prominence complications associated with tILS.

LEVEL OF EVIDENCE

Level III.

A hydrogel spinal dural patch with potential anti-inflammatory, pain relieving and antibacterial effects

CSFL caused by spinal dural defect is a common complication of spinal surgery, which need repair such as suture or sealants. However, low intracranial pressure symptoms, wound infection and prolonged hospital associated with pin-hole leakage or loose seal effect were often occurred after surgical suture or sealants repair. Stable, pressure resistance and high viscosity spinal dural repair patch in wet environment without suture or sealants was highly needed. Herein, a bioactive patch composed of alginate and polyacrylamide hydrogel matrix cross-linked by calcium ions, and chitosan adhesive was proposed. This fabricated patch exhibits the capabilities of promoting defect closure and good tight seal ability with the bursting pressure is more than 790 mm H₂O in wet environment. In addition, the chitosan adhesive layer of the patch could inhibit the growth of bacterial in vitro, which is meaningful for the postoperative infection. Furthermore, the patch also significantly reduced the expression of GFAP, IBA-1, MBP, TNF-α, and COX-2 in early postoperative period in vivo study, exerting the effects of anti-inflammatory, analgesic and adhesion prevention. Thus, the bioactive patch expected to be applied in spinal dural repair with the good properties of withstanding high pressure, promoting defect closure and inhibiting postoperative infection.

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A self-adhesive spinal dural patch that can be applied directly by pressing.

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A spinal dural patch maintains more than 790 mm H₂O sealing pressure in a wet environment.

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A spinal dural patch with potential anti-inflammatory, analgesic and anti-bacterial properties.

Risk factors and management strategies for cerebrospinal fluid leakage following lumbar posterior surgery

OBJECTIVE

To analyze the risk factors of cerebrospinal fluid leakage (CSFL) following lumbar posterior surgery and summarize the related management strategies.

METHODS

A retrospective analysis was performed on 3179 patients with CSFL strategies lumbar posterior surgery in our hospital from January 2019 to December 2020. There were 807 cases of lumbar disc hemiation (LDH), 1143 cases of lumbar spinal stenosi (LSS), 1122 cases of lumbar spondylolisthesis(LS), 93 cases of lumbar degenerative scoliosis(LDS),14 cases of lumbar spinal benign tumor (LST). Data of gender, age, body mass index(BMI), duration of disease, diabete, smoking history, preoperative epidural steroid injection, number of surgical levels, surgical methods (total laminar decompression, fenestration decompression), revision surgery, drainage tube removal time, suture removal time, and complications were recorded.

RESULTS

The incidence of 115 cases with cerebrospinal fluid leakage, was 3.6% (115/3179).One-way ANOVA showed that gender, body mass index (BMI), smoking history, combined with type 2 diabetes and surgical method had no significant effect on CSFL (P > 0.05). Age, type of disease, duration of disease, preoperative epidural steroid injection, number of surgical levels and revision surgery had effects on CSFL (P < 0.05). Multivariate Logistic regression analysis showed that type of disease, preoperative epidural steroid injection, number of surgical levels and revision surgery were significantly affected CSFL (P < 0.05).Drainage tube removal time of CSFL patients ranged from 7 to 11 days, with an average of 7.1 ± 0.5 days, drainage tube removal time of patients without CSFL was 1-3 days, with an average of 2.0 ± 0.1 days, and there was a statistical difference between the two groups (P < 0.05).The removal time of CSFL patients was 12-14 days, with an average of 13.1 ± 2.7 days, and the removal time of patients without CSFL was 10-14 days, with an average of 12.9 ± 2.2 days, there was no statistically significant difference between the two groups (P > 0.05).

CONCLUSION

Type of disease, preoperative epidural steroid injection, number of surgical levels and revision surgery were the risk factors for CSFL. Effective prevention were the key to CSFL in lumbar surgery. Once appear, CSFL can also be effectively dealt without obvious adverse reactions after intraoperative effectively repair dural, head down, adequate drainage after operation, the high position, rehydration treatment, and other treatments.

Open epidural blood patch to augment durotomy repair in lumbar spine surgery: surgical technique and cohort study

BACKGROUND CONTEXT

Incidental durotomy during elective spine surgery is relatively common. While usually benign and self-limited, it can be associated with morbidity, increased cost, and medicolegal ramifications. Dural repair typically involves performing a primary closure using a suture or dural staple; repairs are then frequently augmented with a sealant, patch, or fat/fascial graft. Although primary repair of an incidental durotomy is standard practice, the ideal secondary sealant or augment choice remains unclear. A wide variety of commercially available dural sealant options exist, and while none have demonstrated consistent superiority, all are associated with single-use costs in the hundreds to thousands of dollars and have concerns regarding swelling, local inflammation, or short-lived dural adherence.

PURPOSE

The goal of this study is to compare the results of dural repair augmentation using an open intraoperative epidural blood patch to a hydrogel technique.

STUDY DESIGN/SETTING

Retrospective comparative cohort study at an academic referral center PATIENT SAMPLE: Adult patients undergoing lumbar spine surgery from March 2017 to January 2021 who sustained an incidental durotomy. Patients undergoing surgery for infection were excluded.

OUTCOME MEASURES

The primary outcome was failure of the repair as determined by a return to the operating room for re-exploration of a persistent cerebrospinal fluid (CSF) leak within 30 days of the index procedure. A secondary outcome was the incidence of a postoperative positional headache, and if present, the method used to obtain resolution. The primary predictor was use of a suture and hydrogel technique ("hydrogel" group), or the use of an epidural blood patch ("EBP" group).

METHODS

The method for applying an open epidural blood patch is presented in detail and involves primarily repairing the durotomy followed by allowing whole blood to pool and clot in the operative field until the durotomy is completely covered. This was compared with a group of patients undergoing secondary augmentation with commercially available hydrogel. In both groups, mechanical resistance to CSF leakage was confirmed with direct visualization and a Valsalva maneuver, respectively. Patients were instructed to remain flat until the morning after surgery. Chart review was used for data abstraction on preoperative, demographic, perioperative, and postoperative clinical factors. To compare between the hydrogel and EBP group, Wilcoxon rank-sum testing was used to test for non-parametric comparisons of means, and chi-square testing between binomial data.

RESULTS

Of 732 patients during the study period, forty-eight patients met study criteria. Twenty-five patients were in the hydrogel group and 23 in the EBP group. Mean age was 69.3 years (standard error 1.3 years). Patients were predominantly female (n = 31, 64.6%) with a mean BMI of 29.5 (SE 0.8), with no significant baseline differences between the hydrogel and EBP groups. Two patients in the hydrogel group (8.0%) and two in the EBP group (8.7%) had mild positional headaches postoperatively that resolved without intervention within 24 hours. One (4.3%) patient in the EBP group had positional headaches following an initial headache-free period; this patient was returned to the operating room and no evidence of a persistent CSF leak was found despite meticulous exploration.

CONCLUSIONS

An open, intraoperatively placed epidural blood patch may be an efficacious and cost-effective way to manage an incidental durotomy. This method merits further study as an allergy-free, no swell, cost-neutral method of dural repair augmentation.

Incidence of Dural Tears in Open versus Minimally Invasive Spine Surgery: A Single-Center Prospective Study

Study Design

A prospective comparative study.

Purpose

To compare the incidence of unintended durotomy and return to work after open surgery versus minimally invasive spine surgery (MIS) for degenerative lumbar pathologies.

Overview of Literature

The incidence of accidental durotomy varies between 0.3% and 35%. Most of these are from open surgeries, and only a handful of studies have involved the MIS approach. No single-center studies have compared open surgery with MIS, especially in the context of early return to work and dural tear (DT).

Methods

This study included 420 operated cases of degenerative lumbar pathology with a prospective follow-up of at least 6 months. Patients were divided into the open surgery and MIS groups, and the incidences of DT, early return to work, and various demographic and operative factors were compared.

Results

A total of 156 and 264 patients underwent MIS and open surgery, respectively. Incidental durotomy was documented in 52 cases (12.4%); this was significantly less in the MIS group versus the open surgery group (6.4% vs. 15.9%, p<0.05). In the open surgery group, four patients underwent revision for persistent dural leak or pseudomeningocele, but none of the cases in the MIS group had revision surgery due to DT-related complications. The incidence of DT was higher among patients with high body mass index, patients with diabetes mellitus, and patients who underwent revision surgery (p<0.05) regardless of the approach. The MIS group returned to work significantly earlier.

Conclusions

MIS was associated with a significantly lower incidence of DT and earlier return to work compared with open surgery among patients with degenerative lumbar pathology.

Incidental Durotomy Following Surgery for Degenerative Lumbar Disease and the Impact of Minimally Invasive Surgical Technique on the Rate and Need for Surgical Revision: A Case Series

BACKGROUND

Incidental durotomy (ID) is a common complication during lumbar spine surgery. A paucity of literature has studied the impact of minimally invasive surgery (MIS) on durotomy rates and strategies for repair as compared to open surgery.

OBJECTIVE

To examine the impact that MIS techniques have on the durotomy rate, repair techniques, and need for surgical revision following surgery for degenerative lumbar disease as compared to open technique.

METHODS

A single-center retrospective review of consecutive cases between 2013 and 2016 was performed. All patients underwent lumbar decompression with or without instrumented fusion for degenerative pathology using either open posterior or MIS techniques. ID rate, closure technique, and need for surgical revision related to the durotomy were recorded.

RESULTS

A total of 1,196 patients were included with an overall ID rate of 6.8%. There was no difference between open or minimally invasive surgical techniques (P = .14). There was a higher durotomy rate with open technique in patients that underwent decompression with fusion (P = .03) as well as in revision cases (P = .02). Primary repair was feasible more frequently in the open group (P = .001), whereas use of dural substitute (P < .001) was more common in the MIS group. Fibrin sealant was used routinely in both groups (P = .34). There were no failed repairs, regardless of technique used.

CONCLUSION

MIS techniques may reduce durotomies in cases involving instrumentation or revisions. Use of dural substitute onlay and fibrin sealant was effective at preventing reoperation. Both MIS and open techniques result in a low rate of future surgical revision when a durotomy occurs.

Dural Tear Does not Increase the Rate of Venous Thromboembolic Disease in Patients Undergoing Elective Lumbar Decompression with Instrumented Fusion

OBJECTIVE

Evaluate if dural tears (DTs) are an indirect risk factor for venous thromboembolic disease through increased recumbency in patients undergoing elective lumbar decompression and instrumented fusion.

METHODS

This was a retrospective cohort study of consecutive patients undergoing elective lumbar decompression and instrumented fusion at a single institution between 2016 and 2019. Patients were divided into cohorts: those who sustained a dural tear and those who did not. The cohorts were compared using Student's t-test or Wilcoxon Rank Sum for continuous variables and Fisher exact or chi-squared test for nominal variables.

RESULTS

Six-hundred and eleven patients met inclusion criteria, among which 144 patients (23.6%) sustained a DT. The DT cohort tended to be older (63.6 vs. 60.6 years, P = 0.0052) and have more comorbidities (Charlson Comorbidity Index 2.75 vs. 2.35, P = 0.0056). There was no significant difference in the rate of symptomatic deep vein thrombosis (2.1% vs. 2.6%, P = 1.0) or pulmonary embolus (1.4% vs. 1.50%, P = 1.0). Intraoperatively, DT was associated with increased blood loss (754 mL vs. 512 mL, P < 0.0001), operative time (224 vs. 195 minutes, P < 0.0001), and rate of transfusion (19.4% vs. 9.4%, P = 0.0018). Postoperatively, DT was associated with increased time to ambulation (2.6 vs. 1.4 days, P < 0.0001), length of stay (5.8 vs. 4.0 days, P < 0.0001), and rate of discharge to rehab (38.9 vs. 25.3%, P = 0.0021).

CONCLUSIONS

While DTs during elective lumbar decompression and instrumentation led to later ambulation and longer hospital stays, the increased recumbency did not significantly increase the rate of symptomatic venous thromboembolic disease.

Current Prehabilitation Programs Do Not Improve the Postoperative Outcomes of Patients Scheduled for Lumbar Spine Surgery: A Systematic Review With Meta-analysis

OBJECTIVE

To assess the effectiveness of prehabilitation in patients with degenerative disorders of the lumbar spine who are scheduled for spine surgery.

DESIGN

Intervention systematic review with meta-analysis.

LITERATURE SEARCH

Seven electronic databases were systematically searched for randomized controlled trials or propensity-matched cohorts.

STUDY SELECTION CRITERIA

Studies that measured the effect of prehabilitation interventions (ie, exercise therapy and cognitive behavioral therapy [CBT]) on physical functioning, pain, complications, adverse events related to prehabilitation, health-related quality of life, psychological outcomes, length of hospital stay, use of analgesics, and return to work were included.

DATA SYNTHESIS

Data were extracted at baseline (preoperatively) and at short-term (6 weeks or less), medium-term (greater than 6 weeks and up to 6 months), and long-term (greater than 6 months) follow-ups. Pooled effects were analyzed as mean differences and 95% confidence intervals (CIs). Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

RESULTS

Cognitive behavioral therapy interventions were no more effective than usual care for all outcomes. Pooled effect sizes were -2.0 (95% CI: -4.4, 0.4) for physical functioning, -1.9 (95% CI: -5.2, 1.4) for back pain, and -0.4 (95% CI: -4.1, 0.4) for leg pain. Certainty of evidence for CBT ranged from very low to low. Only 1 study focused on exercise therapy and found a positive effect on short-term outcomes.

CONCLUSION

There was very low-certainty to low-certainty evidence of no additional effect of CBT interventions on outcomes in patients scheduled for lumbar surgery. Existing evidence was too limited to draw conclusions about the effects of exercise therapy. J Orthop Sports Phys Ther 2021;51(3):103-114. Epub 25 Dec 2020. doi:10.2519/jospt.2021.9748.

Influence of unintended dural tears on postoperative outcomes in lumbar surgery patients: a multicenter observational study with propensity scoring

BACKGROUND CONTEXT

Unintended dural tears (DTs) are common in spinal surgeries. Some authors have reported that the outcomes in lumbar surgery patients with DTs are equivalent to those in patients without DTs, but this remains uncertain.

PURPOSE

To assess the effect of unintended DTs on postoperative patient-reported outcomes.

STUDY DESIGN/SETTING

A multicenter retrospective observational study.

PATIENT SAMPLE

We enrolled patients undergoing lumbar spine surgery at eight hospitals between April 2017 and November 2018.

OUTCOME MEASURES

We collected data regarding patients' backgrounds, operative factors, occurrence of unplanned DTs during surgery, postoperative complications, patient-reported outcomes, such as pain or dysesthesia of the lower back, buttock, leg, or plantar area, EuroQol 5 Dimension (EQ-5D), Oswestry Disability Index (ODI) scores, and postoperative satisfaction.

METHODS

We divided the patients into a DT- group (without DTs) and a DT+ group (with DTs). First, multivariate logistic regression analyses were conducted to reveal risk factors for occurrence of DTs. Then, we used propensity score matching to obtain a matched DT- group (mDT- group) and a matched DT+ (mDT+ group). Student's t test was used for comparing continuous variables and Pearson's chi-square test for comparing categorical variables between the two groups.

RESULTS

We enrolled 2,146 patients in this study. The number of patients with unintended DTs was 166 (7.7%). Older age, body mass index, ossification of posterior longitudinal ligament / yellow ligament, spinal deformity, and revision surgery were significant risk factors for DTs. We used propensity score matching to compare 163 of the patients with DTs with 163 patients without DTs. No significant difference was found in postoperative pain or dysesthesia of the lower back, buttock, leg, and plantar area between the mDT- and mDT+ groups. When comparing preoperative with postoperative pain and dysesthesia, a statistically significant improvement was found in each group (p<.01 for all variables) except for sensory disorder of the plantar area, where a significant improvement was only observed in dysesthesia of the mDT- group (p<.01). Although some improvements were observed, they were not statistically significant in terms of pain in the mDT- (p=.06) and mDT+ (p=.13) groups and dysesthesia in the mDT+ (p=.13) group. No significant differences were found in postoperative outcomes, such as EQ-5D (p=.44) and ODI (p=.89) scores, and postoperative satisfaction (p=.73) between the two groups.

CONCLUSIONS

Although insufficient improvement of sensory disorder of the plantar area was observed, patients with DTs showed almost equivalent postoperative outcomes compared with patients without DTs.

Degenerative Lumbar Spine Stenosis Consensus Conference: the Italian job. Recommendations of the Spinal Section of the Italian Society of Neurosurgery

In the modern era evidence-based medicine, guidelines and recommendations represent a key-point of daily activity. The Spinal Section of the Italian Society of Neurosurgery introduced some recommendations regarding Degenerative Lumbar Spine Stenosis based on those of the Spine Committee of World Federation of Neurosurgical Societies, revising them on the basis of Italian common practice. In June 2019, a Committee of 21 spine surgeons met in Rome to validate the recommendations of the WFNS. Furthermore, they decided to review the ones that did not reach a consensus to create Italian Recommendations on Degenerative Lumbar Spine Stenosis. A literature review of the last ten years was performed and the statements were voted using the Delphi method. Forty-one statements were discussed, and 7 statements were voted again to reach a consensus with respect to those of the WFNS. A total of 40 statements reached a consensus, of which 36 reached a positive consensus and 4 a negative consensus, while no consensus was reached in 1 case. Conservative multimodal therapy, tailored on the patient, is a reasonable and effective first option choice for the treatment of LSS patients with tolerable moderate symptoms. Surgical treatment is reserved for symptomatic patients non-responding to conservative treatment or with neurological deficits. The best surgical technique to use depends on personal experience; modern MISS techniques are equivalent to open decompressive surgery with some advantages and higher cost-effectiveness. Fusion surgery and mobility preserving surgery only have a marginal role in the treatment of DLSS without instability.

Incidental durotomy: predictive risk model and external validation of natural language process identification algorithm

OBJECTIVE

Incidental durotomy is a common complication of elective lumbar spine surgery seen in up to 11% of cases. Prior studies have suggested patient age and body habitus along with a history of prior surgery as being associated with an increased risk of dural tear. To date, no calculator has been developed for quantifying risk. Here, the authors' aim was to identify independent predictors of incidental durotomy, present a novel predictive calculator, and externally validate a novel method to identify incidental durotomies using natural language processing (NLP).

METHODS

The authors retrospectively reviewed all patients who underwent elective lumbar spine procedures at a tertiary academic hospital for degenerative pathologies between July 2016 and November 2018. Data were collected regarding surgical details, patient demographic information, and patient medical comorbidities. The primary outcome was incidental durotomy, which was identified both through manual extraction and the NLP algorithm. Multivariable logistic regression was used to identify independent predictors of incidental durotomy. Bootstrapping was then employed to estimate optimism in the model, which was corrected for; this model was converted to a calculator and deployed online.

RESULTS

Of the 1279 elective lumbar surgery patients included in this study, incidental durotomy occurred in 108 (8.4%). Risk factors for incidental durotomy on multivariable logistic regression were increased surgical duration, older age, revision versus index surgery, and case starts after 4 pm. This model had an area under curve (AUC) of 0.73 in predicting incidental durotomies. The previously established NLP method was used to identify cases of incidental durotomy, of which it demonstrated excellent discrimination (AUC 0.97).

CONCLUSIONS

Using multivariable analysis, the authors found that increased surgical duration, older patient age, cases started after 4 pm, and a history of prior spine surgery are all independent positive predictors of incidental durotomy in patients undergoing elective lumbar surgery. Additionally, the authors put forth the first version of a clinical calculator for durotomy risk that could be used prospectively by spine surgeons when counseling patients about their surgical risk. Lastly, the authors presented an external validation of an NLP algorithm used to identify incidental durotomies through the review of free-text operative notes. The authors believe that these tools can aid clinicians and researchers in their efforts to prevent this costly complication in spine surgery.

Natural language processing for automated detection of incidental durotomy

BACKGROUND

Incidental durotomy is a common intraoperative complication during spine surgery with potential implications for postoperative recovery, patient-reported outcomes, length of stay, and costs. To our knowledge, there are no processes available for automated surveillance of incidental durotomy.

PURPOSE

The purpose of this study was to develop natural language processing (NLP) algorithms for automated detection of incidental durotomies in free-text operative notes of patients undergoing lumbar spine surgery.

PATIENT SAMPLE

Adult patients 18 years or older undergoing lumbar spine surgery between January 1, 2000 and June 31, 2018 at two academic and three community medical centers.

OUTCOME MEASURES

The primary outcome was defined as intraoperative durotomy recorded in free-text operative notes.

METHODS

An 80:20 stratified split was undertaken to create training and testing populations. An extreme gradient-boosting NLP algorithm was developed to detect incidental durotomy. Discrimination was assessed via area under receiver-operating curve (AUC-ROC), precision-recall curve, and Brier score. Performance of this algorithm was compared with current procedural terminology (CPT) and international classification of diseases (ICD) codes for durotomy.

RESULTS

Overall, 1,000 patients were included in the study and 93 (9.3%) had a recorded incidental durotomy in the free-text operative report. In the independent testing set (n=200) not used for model development, the NLP algorithm achieved AUC-ROC of 0.99 for detection of durotomy. In comparison, the CPT/ICD codes had AUC-ROC of 0.64. In the testing set, the NLP algorithm detected 16 of 18 patients with incidental durotomy (sensitivity 0.89) whereas the CPT and ICD codes detected 5 of 18 (sensitivity 0.28). At a threshold of 0.05, the NLP algorithm had specificity of 0.99, positive predictive value of 0.89, and negative predictive value of 0.99.

CONCLUSIONS

Internal validation of the NLP algorithm developed in this study indicates promising results for future NLP applications in spine surgery. Pending external validation, the NLP algorithm developed in this study may be used by entities including national spine registries or hospital quality and safety departments to automate tracking of incidental durotomies.

Risk Factors Associated With 90-Day Readmissions After Degenerative Lumbar Fusion: An Examination of the Michigan Spine Surgery Improvement Collaborative (MSSIC) Registry

BACKGROUND

Most studies have evaluated 30-d readmissions after lumbar fusion surgery. Evaluation of the 90-d period, however, allows a more comprehensive assessment of factors associated with readmission.

OBJECTIVE

To assess the reasons and risk factors for 90-d readmissions after lumbar fusion surgery.

METHODS

The Michigan Spine Surgery Improvement Collaborative (MSSIC) registry is a prospective, multicenter, and spine-specific database of patients surgically treated for degenerative disease. MSSIC data were retrospectively analyzed for causes of readmission, and independent risk factors impacting readmission were found by multivariate logistic regression.

RESULTS

Of 10 204 patients who underwent lumbar fusion, 915 (9.0%) were readmitted within 90 d, most commonly for pain (17%), surgical site infection (16%), and radicular symptoms (10%). Risk factors associated with increased likelihood of readmission were other race (odds ratio [OR] 1.81, confidence interval [CI] 1.22-2.69), coronary artery disease (OR 1.57, CI 1.25-1.96), ≥4 fused levels (OR 1.41, CI 1.06-1.88), diabetes (OR 1.34, CI 1.10-1.63), and surgery length (OR 1.09, CI 1.03-1.16). Factors associated with decreased risk were discharge to home (OR 0.63, CI 0.51-0.78), private insurance (OR 0.79, CI 0.65-0.97), ambulation same day of surgery (OR 0.81, CI 0.67-0.97), and spondylolisthesis diagnosis (OR 0.82, CI 0.68-0.97). Of those readmitted, 385 (42.1%) patients underwent another surgery.

CONCLUSION

Ninety-day readmission occurred in 9.0% of patients, mainly for pain, wound infection, and radicular symptoms. Increased focus on postoperative pain may decrease readmissions. Among factors impacting the likelihood of 90-d readmission, early postoperative ambulation may be most easily modifiable. Optimization of preexisting medical conditions could also potentially decrease readmission risk.

Decompression With or Without Fusion for Lumbar Stenosis: A Cost Minimization Analysis

STUDY DESIGN

Retrospective database review.

OBJECTIVE

Compare 1-year episode of care costs between single-level decompression and decompression plus fusion for lumbar stenosis.

SUMMARY OF BACKGROUND DATA

Lumbar stenosis is the most common indication for surgery in patients over 65. Medicare direct hospital costs for lumbar surgery reached $1.65 billion in 2007. Despite stenosis being a common indication for surgery, there is debate as to the preferred surgical treatment. Cost-minimization analysis is a framework that identifies potential cost savings between treatment options that have similar outcomes. We performed a cost-minimization analysis of decompression versus decompression with fusion for lumbar stenosis from the payer perspective.

METHODS

An administrative claims database of privately insured patients (Humana) identified patients who underwent decompression (n = 5349) or decompression with fusion (n = 8540) for lumbar stenosis with and without spondylolisthesis and compared overall costs. All patients were identified and costs identified for a 1-year period. Complication rates and costs were described using summary statistics.

RESULTS

Mean treatment costs at 1 year after surgery were higher for patients who underwent decompression and fusion compared to patients who underwent decompression alone ($20,892 for fusion vs. $6329 for decompression; P < 0.001). Facility costs (P < 0.001), surgeon costs (P < 0.001), and physical therapy costs (P < 0.001) were higher in the fusion group. Cost differences related to infection or durotomy reached significance (P < 0.04). No difference in cost was identified for supplies.

CONCLUSION

Decompression had significantly lower costs for the treatment of lumbar stenosis, including treatment for postoperative complications. If cost minimization is the primary goal, decompression is favored for surgical treatment of lumbar stenosis. Other factors including shared decision-making directed toward patient's values, patient-reported outcomes, and preferences should also be recognized as drivers of healthcare decisions.

LEVEL OF EVIDENCE

3.

The True Effect of a Lumbar Dural Tear on Complications and Cost

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

The aim of this study was to match risk factors for complications in patients who did and did not sustain a dural tear while undergoing posterior lumbar spine surgery and compare local and systemic complications.

SUMMARY OF BACKGROUND DATA

Current data do not adequately define whether the event of sustaining an isolated dural tear increases the risk for postoperative complications while controlling for other confounding risk factors.

METHODS

The PearlDiver Database was queried for patients who underwent posterior lumbar spine decompression and/or fusion for degenerative pathology. Patients with and without dural tears were 1:2 matched based on demographic variables and comorbidities. Complications, cost, length of stay (LOS), and readmission rates were analyzed.

RESULTS

The 1:2 matched cohort included 9038 patients with a dural tear and 17,340 patients without a dural tear. All complications assessed were significantly higher in the dural tear group (P < 0.03). Venothromboembolic (VTE) events occurred in 1.3% of patients with a dural tear and 0.9% of patients without a dural tear (odds ratio [OR] 1.46, P < 0.0001). Meningitis occurred in 25 patients (0.3%) with a dural tear and eight patients (<0.1%) without a dural tear (OR 6.0, P < 0.0001). Patients with a dural tear had 120% higher medical costs, 200% greater LOS, and were two times more likely to be readmitted (P < 0.0001).

CONCLUSION

Sustaining a dural tear while undergoing posterior lumbar spinal decompression and/or fusion for degenerative pathology significantly increased the risk of complications and increased length of stay, risk of readmission, and overall 90-day hospital cost. Dural tears specifically increased the risk of a VTE complication by 1.46 times and meningitis by six times; these are important complications to have a high degree of suspicion for in the setting of durotomy, as they can lead to significant morbidity for the patient.

LEVEL OF EVIDENCE

3.

Spinal subdural hygroma as a post-operative complication in revision spine fusion: a case report

Lumbar spine fusion has become a common and effective procedure in orthopedic practice, and a spinal subdural hygroma development is a rare complication following this procedure. We report here the case of a revision lumbar spine fusion at levels L4-5, L5-S1, where the patient subsequently developed cauda equina syndrome 2 days post-operatively. Magnetic resonance imaging (MRI) showed a subdural, extra-arachnoid fluid collection from T12-L2, cephalad to the site of spine fusion. It appears the first case reported a subdural hygroma developed cephalad to the site of spine fusion. When a patient complains of radicular pain along with urinary retention and neurologic deficits post-lumbar spine surgery, cauda equina syndrome possibly caused by subdural hygroma should be considered. This warrants immediate MRI and emergent reoperation to relieve the pressure on the spinal cord may be necessary.

Prognostic impact of intra- and postoperative management of dural tear on postoperative complications in primary degenerative lumbar diseases

Aims

The aim of this study was to explore risk factors for complications associated with dural tear (DT), including the types of DT, and the intra- and postoperative management of DT.

Patients and Methods

Between 2012 and 2017, 12 171 patients with degenerative lumbar diseases underwent primary lumbar spine surgery. We investigated five categories of potential predictors: patient factors (sex, age, body mass index, and primary disease), surgical factors (surgical procedures, operative time, and estimated blood loss), types of DT (inaccessible for suturing/clipping and the presence of cauda equina/nerve root herniation), repair techniques (suturing, clipping, fibrin glue, polyethylene glycol (PEG) hydrogel, and polyglycolic acid sheet), and postoperative management (drainage duration). Postoperative complications were evaluated in terms of dural leak, prolonged bed rest, headache, nausea/vomiting, delayed wound healing, postoperative neurological deficit, surgical site infection (SSI), and reoperation for DT. We performed multivariable regression analyses to evaluate the predictors of postoperative complications associated with DT.

Results

In total, 429/12 171 patients (3.5%) had a DT. Multivariable analysis revealed that PEG hydrogel significantly reduced the incidence of dural leak and prolonged bed rest, and that patients treated with sealants (fibrin glue and PEG hydrogel) significantly less frequently suffered from headache. A longer drainage duration significantly increased the incidence of headache, nausea/vomiting, and delayed wound healing. Headache and nausea/vomiting were significantly more prevalent in younger female patients. Postoperative neurological deficit and reoperation for DT significantly depended on the presence of cauda equina/nerve root herniation. A longer operative time was the sole independent risk factor for SSI and was also a risk factor for dural leak, prolonged bed rest, and nausea/vomiting.

Conclusion

Sealants, particularly PEG hydrogel, may be useful in reducing symptoms related to cerebrospinal fluid leakage, whereas prolonged drainage may be unnecessary. Younger female patients should be carefully treated when DT occurs. Cite this article: Bone Joint J 2019;101-B:1115–1121.

Cerebrospinal fluid leaks after spine tumor resection: avoidance, recognition and management

Post-operative CSF leaks are a known complication of spine surgery in general, and patients undergoing surgical intervention for spinal tumors may be particularly predisposed due to the presence of intradural tumor and a number of other factors. Post-operative CSF leaks increase morbidity, lengthen hospital stays, prolong immobilization and subject patients to a number of associated complications. Intraoperative identification of unintended durotomies and effective primary repair of dural defects is an important first step in the prevention of post-operative CSF leaks, but in patients who develop post-operative pseudomeningoceles, durocutaneous fistulae or other CSF-leak-related sequelae, early recognition and secondary intervention are paramount to preventing further CSF-leak-related complications and achieving the best patient outcomes possible. In this article, the incidence, risk factors and complications of CSF leaks after spine tumor surgery are reviewed, with an emphasis on avoidance of post-operative CSF leaks, early post-operative identification and effective secondary intervention.

Dural tear is associated with an increased rate of other perioperative complications in primary lumbar spine surgery for degenerative diseases

Prospective case-control study.This study used a prospective multicenter database to investigate whether dural tear (DT) is associated with an increased rate of other perioperative complications.Few studies have had sufficient data accuracy and statistical power to evaluate the association between DT and other complications owing to a low incidence of occurrence.Between 2012 and 2017, 13,188 patients (7174 men and 6014 women) with degenerative lumbar diseases underwent primary lumbar spine surgery. The average age was 64.8 years for men and 68.7 years for women. DT was defined as a tear that was detected intraoperatively. Other investigated intraoperative surgery-related complications were massive hemorrhage (>2 L of blood loss), nerve injury, screw malposition, cage/graft dislocation, surgery performed at the wrong site, and vascular injury. The examined postoperative surgery-related complications were dural leak, surgical-site infection (SSI), postoperative neurological deficit, postoperative hematoma, wound dehiscence, screw/rod failure, and cage/graft failure. Information related to perioperative systemic complications was also collected for cardiovascular diseases, respiratory diseases, renal and urological diseases, cerebrovascular diseases, postoperative delirium, and sepsis.DTs occurred in 451/13,188 patients (3.4%, the DT group). In the DT group, dural leak was observed in 88 patients. After controlling for the potentially confounding variables of age, sex, primary disease, and type of procedure, the surgery-related complications that were more likely to occur in the DT group than in the non-DT group were SSI (odds ratio [OR] 2.68) and postoperative neurological deficit (OR 3.27). As for perioperative systemic complications, the incidence of postoperative delirium (OR 3.21) was significantly high in the DT group.This study demonstrated that DT was associated with higher incidences of postoperative SSI, postoperative neurological deficit, and postoperative delirium, in addition to directly DT-related dural leak.

Risk Factors and Management of Incidental Durotomy in Lumbar Interbody Fusion Surgery

STUDY DESIGN

This is a retrospective study analysis.

OBJECTIVE

In this retrospective study we evaluated risk factors for incidental durotomy and its impact on the postoperative course.

SUMMARY OF BACKGROUND DATA

Lumbar interbody fusion (LIF) is increasingly applied for the treatment of degenerative instability. A known complication is incidental durotomy.

MATERIALS AND METHODS

A cohort of 541 patients who underwent primary LIF surgery between 2005 and 2015 was analyzed. Previous lumbar surgery, age, surgeon's experience, intraoperative use of a microscope, and the number of operated levels were assessed and the risk for incidental durotomy was estimated using the Log-likelihood test and Wald test, respectively. The association of incidental durotomy and outcome parameters was analyzed using the quantile regression model.

RESULTS

In 77 (14.2%) patients intraoperative cerebrospinal fluid (CSF) fistula was observed. Previous lumbar surgery (P<0.001), number of operated levels (P=0.03), and surgeon's experience (P=0.01) were significantly associated with incidental durotomy. Incidental durotomy was significantly associated with a prolonged bed rest (P<0.001), hospital stay (P=0.041), and an increased use of postoperative antibiotics (P<0.001). Eleven of 77 patients with incidental durotomy (14.3%) developed postoperative CSF fistula of whom 10 (91%) needed revision surgery for dural repair.

CONCLUSIONS

We could identify important risk factors for incidental durotomy in LIF surgery. In patients who had undergone previous lumbar surgery and those with multilevel disease particular precaution is required. Furthermore, we were able to verify the morbidity associated with CSF fistula as shown by increased immobilization and follow-up surgeries for postoperative CSF fistula which emphasizes the importance to develop strategies to minimize the risk for incidental durotomy.

Dural Tears in Adult Deformity Surgery: Incidence, Risk Factors, and Outcomes

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Describe the rate of dural tears (DTs) in adult spinal deformity (ASD) surgery. Describe the risk factors for DT and the impact of this complication on clinical outcomes.

METHODS

Patients with ASD undergoing surgery between 2008 and 2014 were separated into DT and non-DT cohorts; demographics, operative details, radiographic, and clinical outcomes were compared. Statistical analysis included t tests or χ² tests as appropriate and a multivariate analysis.

RESULTS

A total of 564 patients were identified. The rate of DT was 10.8% (n = 61). Patients with DT were older (61.1 vs 56.5 years, P = .005) and were more likely to have had prior spine surgery (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.2-3.3, P = .007). DT patients had higher pelvic tilt, lower lumbar lordosis, and greater pelvic-incidence lumbar lordosis mismatch than non-DT patients (P < .05). DT patients had longer operative times (424 vs 375 minutes, P = .008), were more likely to undergo interbody fusions (OR = 2.0, 95% CI = 1.1-3.6, P = .021), osteotomies (OR = 2.2, 95% CI = 1.1-4.0, P = .012), and decompressions (OR = 2.3, 95% CI = 1.3-4.3, P = .003). In our multivariate analysis, only decompressions were associated with an increased risk of DT (OR = 3.2, 95% CI = 1.4-7.6, P = .006). There were no significant differences in patient outcomes at 2 years.

CONCLUSIONS

The rate of DT was 10.8% in an ASD cohort. This is similar to rates of DT reported following surgery for degenerative pathology. A history of prior spine surgery, decompression, interbody fusion, and osteotomies are all associated with an increased risk of DT, but decompression is the only independent risk factor for DT.

Lateral lumbar retroperitoneal transpsoas approach in the setting of spondylodiscitis: A technical note

Thoracolumbar spondylodiscitis is a morbid disease entity, impacting a sick patient population with multiple comorbidities. Wherever possible, surgical measures in this population should limit the extent of soft tissue disruption and overall morbidity that is often associated with anteroposterior thoracolumbar decompression and fusion. The authors describe the rationale, technique, and use of the lateral lumbar transpsoas retroperitoneal approach in tandem with posterior decompression and instrumented fusion in the treatment of circumferential thoracolumbar spondylodiscitis with or without epidural abscesses. The authors have routinely implemented the lateral lumbar transpsoas retroperitoneal approaches to address all pyogenic vertebral abscesses, spondylodiscitis, and ventral epidural abscesses with anterior column debridement and reconstruction with iliac crest autograft, posterior decompression, and pedicle screw instrumentation. In five consecutive patients, the mean blood loss and operative duration was 275mL and 259min, respectively. There were no instances of major vascular injury as this corridor obviates the need for retraction of inflamed retroperitoneal structures. The use of the lumbar lateral retroperitoneal transpsoas approach to the lumbar spine for the treatment of destructive and pyogenic spondylodiscitis is a potential alternative to the traditional anterior lumbar retroperitoneal approach in tandem with posterior spinal decompression and instrumented stabilization.

Perifascial Areolar Tissue Graft for Spinal Dural Repair with Cerebrospinal Fluid Leakage: Case Report of Novel Graft Material, Radiological Assessment Technique, and Rare Postoperative Hydrocephalus

BACKGROUND

Incidental durotomy is a relatively common complication in spinal surgeries, and treatment of persistent cerebrospinal fluid (CSF) leakage is still challenging, especially in cases for which "watertight" suturing is inapplicable. The usefulness of a nonvascularized perifascial areolar tissue (PAT) graft recently was emphasized for plastic and skull base surgeries. Its hypervascularity allows for early engraftment and long-term survival, and its flexibility is advantageous in fixing defects of complex shapes in limited surgical spaces.

CASE DESCRIPTION

The authors report a case of persistent CSF leakage after cervical spine surgery in which a PAT graft was used successfully for direct closure of the dural defect. The noninvasive, spin-labeled magnetic resonance imaging technique was used for postoperative assessment of CSF dynamics, not for CSF accumulation but for CSF leakage itself. In addition, some potential causes for the rare development of communicating hydrocephalus after cervical laminoplasty, as seen in this case, are discussed.

CONCLUSIONS

PAT was used successfully as an alternative free graft material for direct spinal dural closure, and its hypervascularity seemed to assist with rapid resolution of CSF leakage in our case. Spin-labeled magnetic resonance imaging may enable assessment of spinal CSF dynamics without invasion.

Complications following central corpectomy in 468 consecutive patients with degenerative cervical spine disease

OBJECTIVE

This study was performed to describe the incidence and predictors of perioperative complications following central corpectomy (CC) in 468 consecutive patients with cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL).

METHODS

The authors performed a retrospective review of a cohort of patients who had undergone surgery for CSM (n = 338) or OPLL (n = 130) performed by a single surgeon over a 15-year period. All patients underwent uninstrumented CC with autologous iliac crest or fibular strut grafting. Preoperative clinical and imaging details were collected, and the type and incidence of complications were studied. Univariate and multivariate analyses were performed to establish risk factors for the development of perioperative complications.

RESULTS

Overall, 12.4% of patients suffered at least 1 complication following CC. The incidence of major complications was as follows: C-5 radiculopathy, 1.3%; recurrent laryngeal nerve injury, 0.4%; dysphagia, 0.8%; surgical-site infection, 3.4%; and dural tear, 4.3%. There was 1 postoperative death (0.2%). On multivariate analysis, patients in whom the corpectomy involved the C-4 vertebral body (alone or as part of multilevel CC) were significantly more likely to suffer complications (p = 0.004). OPLL and skip corpectomy were risk factors for dural tear (p = 0.015 and p = 0.001, respectively). No factors were found to be significantly associated with postoperative C-5 palsy, dysphagia, or acute graft extrusion on univariate or multivariate analysis. Patients who underwent multilevel CC were predisposed to surgical-site infections, with a slight trend toward statistical significance (p = 0.094). The occurrence of a complication after surgery significantly increased the mean duration of postoperative hospital stay from 5.0 ± 2.3 days to 8.9 ± 6 days (p < 0.001).

CONCLUSIONS

Complications following CC for CSM or OPLL are infrequent, but they significantly prolong hospital stay. The most frequent complication following CC is dural tear, for which a diagnosis of OPLL and a skip corpectomy are significant risk factors.