Implementation of a Spine-Centered Care Pathway at a Regional Academic Spine Center

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To describe the early implementation of an inpatient spinal surgery unit and measure the impact on cost and length of stay (LOS).

METHODS

A retrospective case review was performed for frequent spine-related diagnosis-related groups (DRGs) cared for by a dedicated multidisciplinary team: combined anterior/posterior (AP) spinal fusion with major complicating or comorbid condition (MCC), combined (AP) spinal fusion with CC, combined (AP) spinal fusion without complicating or comorbid (CC)/MCC, cervical spinal fusion with MCC, cervical spinal fusion with CC, and cervical spinal fusion without CC/MCC. Four time periods were compared: historical control, initial pathway implementation, full pathway implementation, and spine unit opening. Mean hospital LOS, mean and median total costs (USD), and ratio of costs-to-charges were analyzed.

RESULTS

The number of spine cases per interim ranged from 219 to 258. The mean overall hospital LOS and mean cost varied from 3.8 to 4.3 days for all DRGs across the time periods and was not significant. Cost also did not vary significantly throughout. Median variable cost per anterior/posterior spinal fusion procedure with a CC or MCC declined by 16 311, first with the institution of a spine pathway protocol by USD8738 and then USD7423 with the establishment of a spine care unit but did not reach significance.

CONCLUSIONS

The use of a standardized, inpatient spine care pathway implemented by a multidisciplinary team may reduce the hospital length of stay and decrease overall costs.

Minimizing Blood Loss in Spine Surgery

STUDY DESIGN

Broad narrative review.

OBJECTIVE

To review and summarize the current literature on guidelines, outcomes, techniques and indications surrounding multiple modalities of minimizing blood loss in spine surgery.

METHODS

A thorough review of peer-reviewed literature was performed on the guidelines, outcomes, techniques, and indications for multiple modalities of minimizing blood loss in spine surgery.

RESULTS

There is a large body of literature that provides a consensus on guidelines regarding the appropriate timing of discontinuation of anticoagulation, aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and herbal supplements prior to surgery. Additionally, there is a more heterogenous discussion the utility of preoperative autologous blood donation facilitated by erythropoietin and iron supplementation for healthy patients slated for procedures with high anticipated blood loss and for whom allogeneic transfusion is likely. Intraoperative maneuvers available to minimize blood loss include positioning and maintaining normothermia. Tranexamic acid (TXA), bipolar sealer electrocautery, and topical hemostatic agents, and hypotensive anesthesia (mean arterial pressure (MAP) <65 mm Hg) should be strongly considered in cases with larger exposures and higher anticipated blood loss. There is strong level 1 evidence for the use of TXA in spine surgery as it reduces the overall blood loss and transfusion requirements.

CONCLUSION

As the volume and complexity of spinal procedures rise, intraoperative blood loss management has become a pivotal topic of research within the field. There are many tools for minimizing blood loss in patients undergoing spine surgery. The current literature supports combining techniques to use a cost- effective multimodal approach to minimize blood loss in the perioperative period.

Minimally Invasive Lumbar Interbody Fusion With an Expandable Meshed Allograft Containment Device: Analysis of Subsidence With 12-Month Minimum Follow-Up

Background

We have previously reported the use of a minimally invasive allograft-filled expandable meshed-bag containment system in the lumbar spine. Subsidence has not been reported with this device. In this retrospective case series, we describe subsidence after lumbar interbody fusion using this device, with 12-month minimum radiographic follow-up.

Methods

Consecutive adult patients that underwent 1- or 2-level interbody fusion with at least 1 year of follow-up were included in this study. Preoperative, postoperative, and final follow-up lumbar radiographs were analyzed to measure disc height at the anterior and posterior margins of the disc space, as well as the neuroforaminal height.

Results

Forty-one patients were identified, with a mean age of 63.4 years (± 11.8). A total of 61 levels were treated, with successful fusion observed in 54 levels (88.5%). The mean radiographic follow-up was 24.3 months (± 11.2). The mean disc height pre- and postoperatively was 6.9 mm (± 3.2) and 10.1 mm (± 2.9, P < .001), respectively. The mean disc height at final follow-up was 8.3 mm (± 2.4). Average disc height subsidence was 1.8 mm (± 1.7, P < .001). Overall, average disc height increased by a net 1.3 mm (± 2.5, P < .001). The mean neuroforaminal height pre- and postoperatively was 18.0 mm (± 3.3) and 20.7 mm (± 3.6, P < .001), respectively. The mean neuroforaminal height at final follow-up was 19.2 mm (± 3.4). Average neuroforaminal height subsidence was 1.3 mm (± 3.4, P = .012). Overall, average neuroforaminal height increased by a net 1.7 mm (± 2.8, P = .004). No significant difference in subsidence was observed between 1- and 2-level surgeries.

Conclusion

An expandable allograft containment system is a feasible alternative for lumbar interbody fusion. Due to its biologic and mechanical nature, the surgeon using such constructs should account for an anticipated average of 18% loss of interbody height due to subsidence during the bony remodeling/fusion process.

Surgical Site Infection as a Risk Factor for Long-Term Instrumentation Failure in Patients with Spinal Deformity: A Retrospective Cohort Study

BACKGROUND

Surgical site infection (SSI) remains a complication of spine deformity surgery. Although fusion/instrumentation failure in the setting of SSI has been reported, few studies have investigated the relationship between these entities. We examine the relationship between early SSI and fusion/instrumentation failure after instrumented fusion in patients with thoracolumbar scoliosis.

METHODS

A retrospective review of a prospectively maintained case series for patients undergoing spine surgery between January 1, 2006, and October 3, 2017. Inclusion criteria included age ≥18 years and surgery performed for correction of thoracolumbar scoliosis. Data collected included various demographic, clinical, and operative variables.

RESULTS

532 patients met inclusion criteria, with 20 (4%) experiencing SSI. Diabetes mellitus was the only demographic risk factor for increased SSI (P = 0.026). Number of fused levels, blood volume loss, and operative time were similar between groups. Fusion/instrumentation failure occurred in 68 (13%) patients, 10 of whom (15%) had SSI, whereas of the 464 patients with no fusion/instrumentation failure, only 10 (2%) had SSI (P < 0.001). Of the 20 patients with SSI, 10 (50%) had fusion/instrumentation failure, whereas in the 512 patients with no infection, only 58 (11%) had fusion/instrumentation failure (P < 0.001). Patients with infection also experienced significantly shorter time to fusion/instrumentation failure (P = 0.025), higher need for revision surgery (P < 0.001), and shorter time to revision surgery (P = 0.012).

CONCLUSIONS

Early SSI significantly increases the risk of fusion/instrumentation failure in patients with thoracolumbar scoliotic deformity, and it significantly shortens the time to failure. Patients with early SSI have a significantly higher likelihood of requiring revision surgery and after a significantly shorter time interval.

Surgical Treatment of Vascular Intramedullary Spinal Cord Lesions

Background Vascular lesions represent a rare subset of intramedullary spinal cord pathology and consist of cavernous malformations (CM), hemangioblastomas, and arteriovenous malformations (AVM). These lesions are each unique and the literature pertaining to their surgical management is largely limited to retrospective case series and case reports. Objectives To evaluate the surgical management of each of these lesions with special attention to postoperative functional status. Methods A single-institution case series of intramedullary vascular lesions treated with surgery was retrospectively evaluated. The primary variables of interest included preoperative and postoperative McCormick grades. Other variables of interest included frequency and indication for conventional spinal angiography, rates of preoperative embolization, postprocedural complications, operative time, intraoperative blood loss, and length of hospital stay. Results Thirty-six patients were identified over the 17-year study period, including 20 with hemangioblastomas, 13 with CMs, and three with AVMs. The median preoperative McCormick grades were 2, 2, and 3 for hemangioblastomas, CMs, and AVMs, respectively. The median postoperative McCormick grades were 2, 2, and 2 for hemangioblastomas, CMs, and AVMs, respectively at the most recent follow-up. Preoperative angiography was performed in all AVM cases and 29% of hemangioblastomas. Preoperative embolization was performed in 40% of hemangioblastoma cases undergoing preoperative angiography. Operative times were similar between the three lesion groups. In three cases of hemangioblastoma resection and one case of CM resection, McCormick grade improved by one point following surgery. At a mean follow-up of 30.9 months for hemangioblastomas, 7.95 months for CMs, and 24 months for AVMs, all patients were at least at their discharge baseline, with no new neurologic complaints. Conclusion Intramedullary vascular lesions are rare and represent a complex surgical patient population. Surgical resection with or without preoperative angiography and embolization appears to be safe and to halt neurologic decline.

Preoperative skin antisepsis with chlorhexidine gluconate versus povidone-iodine: a prospective analysis of 6959 consecutive spinal surgery patients

OBJECTIVE The aim of this study was to determine the efficacy of 2 common preoperative surgical skin antiseptic agents, ChloraPrep and Betadine, in the reduction of postoperative surgical site infection (SSI) in spinal surgery procedures. METHODS Two preoperative surgical skin antiseptic agents-ChloraPrep (2% chlorhexidine gluconate and 70% isopropyl alcohol) and Betadine (7.5% povidone-iodine solution)-were prospectively compared across 2 consecutive time periods for all consecutive adult neurosurgical spine patients. The primary end point was the incidence of SSI. RESULTS A total of 6959 consecutive spinal surgery patients were identified from July 1, 2011, through August 31, 2015, with 4495 (64.6%) and 2464 (35.4%) patients treated at facilities 1 and 2, respectively. Sixty-nine (0.992%) SSIs were observed. There was no significant difference in the incidence of infection between patients prepared with Betadine (33 [1.036%] of 3185) and those prepared with ChloraPrep (36 [0.954%] of 3774; p = 0.728). Neither was there a significant difference in the incidence of infection in the patients treated at facility 1 (52 [1.157%] of 4495) versus facility 2 (17 [0.690%] of 2464; p = 0.06). Among the patients with SSI, the most common indication was degenerative disease (48 [69.6%] of 69). Fifty-one (74%) patients with SSI had undergone instrumented fusions in the index operation, and 38 (55%) patients with SSI had undergone revision surgeries. The incidence of SSI for minimally invasive and open surgery was 0.226% (2 of 885 cases) and 1.103% (67 of 6074 cases), respectively. CONCLUSIONS The choice of either ChloraPrep or Betadine for preoperative skin antisepsis in spinal surgery had no significant impact on the incidence of postoperative SSI.

Multilevel Schwab grade II osteotomies for sagittal plane correction in the management of adult spinal deformity

BACKGROUND CONTEXT

Prior reports have compared posterior column osteotomies with pedicle subtraction osteotomies in terms of utility for correcting fixed sagittal imbalance in adolescent patients with deformity. No prior reports have described the use of multilevel Smith-Petersen Osteotomies (SPOs) alone for surgical correction in the adult spinal deformity (ASD) population.

PURPOSE

The study aimed to determine the utility of multilevel SPOs in the management of global sagittal imbalance in ASD patients.

STUDY DESIGN/SETTING

This is a retrospective observational study at a single academic center.

PATIENT SAMPLE

The sample included 85 ASD patients.

OUTCOME MEASURES

This is a radiographic outcomes cohort study.

METHODS

The radiographs of 85 ASD patients were retrospectively evaluated before and after long-segment (>5 spinal levels) fusion and multilevel SPO (≥3 levels) for sagittal imbalance correction. The number of osteotomies, correction in regional lumbar lordosis (LL), and correction per osteotomy was evaluated. Independent predictors of correction per SPO were evaluated with a hierarchical linear regression analysis.

RESULTS

Eighty-five patients (mean age: 67.5±11 years) were identified with ASD (372 SPOs). The mean preoperative sagittal vertical axis (SVA) and T1 pelvic angle (TPA) were 8.16±6.75 cm and 25°±13.23°, respectively. The mean postoperative central sacral vertical line (CSVL) and SVA were 0.67±0.70 cm and 1.29±5.41 cm, respectively. The mean improvement in SVA was 6.29 cm achieved with a correction of approximately 5.05° per SPO. The mean LL restoration was 20.3°±13.9°, and 33(39%) patients achieved a final pelvic incidence minus lumbar lordosis (PI-LL) ≤10°. Fifty-four (64%) achieved a postoperative PI-LL ≤15°, 75 (88%) with a PI-LL ≤20°, and 85 (100%) achieved a PI-LL ≤25°. Correction per SPO was similar regardless of prior fusion (4.87° vs. 5.72° for revisions, p=.192). In a subgroup analysis of SVA greater than 10 cm, there was no significant difference in the final LL, thoracic kyphosis, PI-LL, SVA, CSVL, and TPA, as compared with SVA <10 cm. The LL was the only independent predictor of osteotomy correction per level (LL: β coefficient=-0.108, confidence interval: -0.141 to 0.071, p<.0001).

CONCLUSIONS

Multilevel SPOs are feasible for restoration of LL as well as sagittal and coronal alignment in the ASD population with or without prior instrumented fusion.

Minimally invasive direct pars repair with cannulated screws and recombinant human bone morphogenetic protein: case series and review of the literature

OBJECTIVE

The objective of this study was to describe the use of a minimally invasive surgical treatment of lumbar spondylolysis in athletes by a fluoroscopically guided direct pars screw placement with recombinant human bone morphogenetic protein–2 (rhBMP-2) and to report on clinical and radiographic outcomes.

METHODS

A retrospective review was conducted of all patients treated surgically for lumbar spondylolysis via a minimally invasive direct pars repair with cannulated screws. Demographic information, clinical features of presentation, perioperative and intraoperative radiographic imaging, and postoperative data were collected. A 1-cm midline incision was performed for the placement of bilateral pars screws utilizing biplanar fluoroscopy, followed by placement of a fully threaded 4.0-mm-diameter titanium cannulated screw. A tubular table-mounted retractor was utilized for direct pars fracture visualization and debridement through a separate incision. The now-visualized pars fracture could then be decorticated, with care taken not to damage the titanium screw when using a high-speed drill. Local bone obtained from the curettage was then placed in the defect with 1.05 mg rhBMP-2 divided equally between the bilateral pars defects.

RESULTS

Nine patients were identified (mean age 17.7 ± 3.42 years, range 14–25 years; 6 male and 3 female). All patients had bilateral pars fractures of L-4 (n = 4) or L-5 (n = 5). The mean duration of preoperative symptoms was 17.22 ± 13.2 months (range 9–48 months). The mean operative duration was 189 ± 29 minutes (range 151–228 minutes). The mean intraoperative blood loss was 17.5 ± 10 ml (range 10–30 ml). Radiographic follow-up was available in all cases; the mean length of time from surgery to the most recent imaging study was 30.8 ± 23.3 months (range 3–59 months). The mean hospital length of stay was 1.13 ± 0.35 days (range 1–2 days). There were no intraoperative complications.

CONCLUSIONS

Lumbar spondylolysis treatment with a minimally invasive direct pars repair is a safe and technically feasible option that minimizes muscle and soft-tissue dissection, which may particularly benefit adolescent patients with a desire to return to a high level of physical activity.

Suture Choice in Lumbar Dural Closure Contributes to Variation in Leak Pressures: Experimental Model

STUDY DESIGN

Open-label laboratory investigational study; non-animal surgical simulation.

OBJECTIVE

The authors perform a comparison of dural closure strength in a durotomy simulator across 2 different suture materials.

SUMMARY OF BACKGROUND DATA

Incidental durotomy leading to persistent cerebrospinal fluid leak adds considerable morbidity to spinal procedures, often complicating routine elective lumbar spinal procedures. Using an experimental durotomy simulation, the authors compare the strength of closure using Gore-Tex with other suture types and sizes, using various closure techniques.

METHODS

A comparison of dural closures was performed through an analysis of the peak pressure at which leakage occurred from a standardized durotomy closure in an established cerebrospinal fluid repair model with a premade L3 laminectomy. Nurolon was compared with Gore-Tex sutures sizes (for Gore-Tex, CV-6/5-0 and CV-5/4-0 was compared with Nurolon 4-0, 5-0, and 6-0).

RESULTS

Thirty-six trials were performed with Nurolon 4-0, 5-0, and 6-0, whereas 21 trials were performed for 4-0 and 5-0 Gore-Tex. The mean peak pressure at which fluid leakage was observed was 21 cm H2O for Nurolon and 34 cm H2O for Gore-Tex. Irrespective of suture choice, all trials were grouped by closure technique: running suture, locked continuous, and interrupted suture. No significant difference was noted between the groups. For each of the 3 trials groups by closure technique, running, locked continuous, and interrupted, Gore-Tex closures had a significantly higher peak pressure to failure. Interrupted Gore-Tex was significantly higher than Interrupted Nurolon (P=0.007), running Gore-Tex was significantly higher than running Nurolon (P=0.034), and locked Gore-Tex was significantly higher than locked Nurolon (P=0.014).

CONCLUSIONS

Durotomy closure in the lumbar spine with Gore-Tex suture may be a reasonable option for providing a watertight closure. In this laboratory study, Gore-Tex suture provided watertight dural closures that withstood higher peak pressures.

Cervical Spondylodiscitis: Presentation, Timing, and Surgical Management in 59 Patients

BACKGROUND

Cervical spondylodiscitis is thought to carry a significant risk for rapid neurologic deterioration with a poor response to nonsurgical management.

METHODS

A retrospective surgical case series of the acute surgical management of cervical spondylodiscitis is reviewed to characterize the neurologic presentation and postoperative neurologic course in a relatively uncommon disease.

RESULTS

Fifty-nine patients were identified (mean age, 59 years [range, 18-83 years; SD ± 13.2 years]) from a single-institution neurosurgical database. The most common levels of radiographic cervical involvement were C4-C5, C5-C6, and C6-C7, in descending order. Overall, statistically significant clinical improvement was noted after surgery (P < 0.05). Spinal cord hyperintensity on T2-weighted magnetic resonance imaging was significantly associated with a worse preoperative neurologic grade (P = 0.036), but did not correlate with a relatively worse neurologic outcome by discharge. No significant difference was noted between potential preoperative predictors (organism cultured, presence of epidural abscess, tobacco use, early surgery within 24 hours of clinical presentation) and preoperative American Spinal Injury Association injury scale, with the exception of the duration between symptom onset and surgical intervention. A negative correlation between increased preoperative duration of symptoms and magnitude in motor improvement was observed. Relative to anteroposterior decompression and fusion, anterior treatment alone demonstrated a relatively greater effect in neurologic improvement.

CONCLUSIONS

Cervical spondylodiscitis is a rare disease that typically manifests with preoperative motor deficits. Surgery was associated with a significant improvement in motor score by hospital discharge. Significant predictors of neurologic improvement were not observed. Prolonged symptomatic duration was correlated with a significantly lower likelihood of motor score improvement.

Anterior Cervical Infection: Presentation and Incidence of an Uncommon Postoperative Complication

STUDY DESIGN

Retrospective multi-institutional case series.

OBJECTIVE

The anterior cervical discectomy and fusion (ACDF) affords the surgeon the flexibility to treat a variety of cervical pathologies, with the majority being for degenerative and traumatic indications. Limited data in the literature describe the presentation and true incidence of postoperative surgical site infections.

METHODS

A retrospective multicenter case series study was conducted involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network, selected for their excellence in spine care and clinical research infrastructure and experience. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, inclusive, were reviewed to identify the occurrence of 21 predefined treatment complications. Patients who underwent an ACDF were identified in the database and reviewed for the occurrence of postoperative anterior cervical infections.

RESULTS

A total of 8887 patients were identified from a retrospective database analysis of 21 centers providing data for postoperative anterior cervical infections (17/21, 81% response rate). A total of 6 postoperative infections after ACDF were identified for a mean rate of 0.07% (range 0% to 0.39%). The mean age of patients identified was 57.5 (SD = 11.6, 66.7% female). The mean body mass index was 22.02. Of the total infections, half were smokers (n = 3). Two patients presented with myelopathy, and 3 patients presented with radiculopathic-type complaints. The mean length of stay was 4.7 days. All patients were treated aggressively with surgery for management of this complication, with improvement in all patients. There were no mortalities.

CONCLUSION

The incidence of postoperative infection in ACDF is exceedingly low. The management has historically been urgent irrigation and debridement of the surgical site. However, due to the rarity of this occurrence, guidance for management is limited to retrospective series.

Use of liposomal bupivacaine in the postoperative management of posterior spinal decompression

OBJECTIVE

The aim in this paper was to evaluate the efficacy of long-acting liposomal bupivacaine in comparison with bupivacaine hydrochloride for lowering postoperative analgesic usage in the management of posterior cervical and lumbar decompression and fusion.

METHODS

A retrospective cohort-matched chart review of 531 consecutive cases over 17 months (October 2013 to February 2015) for posterior cervical and lumbar spinal surgery procedures performed by a single surgeon (J.J.) was performed. Inclusion criteria for the analysis were limited to those patients who received posterior approach decompression and fusion for cervical or lumbar spondylolisthesis and/or stenosis. Patients from October 1, 2013, through December 31, 2013, received periincisional injections of bupivacaine hydrochloride, whereas after January 1, 2014, liposomal bupivacaine was solely administered to all patients undergoing posterior approach cervical and lumbar spinal surgery through the duration of treatment. Patients were separated into 2 groups for further analysis: posterior cervical and posterior lumbar spinal surgery.

RESULTS

One hundred sixteen patients were identified: 52 in the cervical cohort and 64 in the lumbar cohort. For both cervical and lumbar cases, patients who received bupivacaine hydrochloride required approximately twice the adjusted morphine milligram equivalent (MME) per day in comparison with the liposomal bupivacaine groups (5.7 vs 2.7 MME, p = 0.27 [cervical] and 17.3 vs 7.1 MME, p = 0.30 [lumbar]). The amounts of intravenous rescue analgesic requirements were greater for bupivacaine hydrochloride in comparison with liposomal bupivacaine in both the cervical (1.0 vs 0.39 MME, p = 0.31) and lumbar (1.0 vs 0.37 MME, p = 0.08) cohorts as well. None of these differences was found to be statistically significant. There were also no significant differences in lengths of stay, complication rates, or infection rates. A subgroup analysis of both cohorts of opiate-naive versus opiate-dependent patients found that those patients who were naive had no difference in opiate requirements. In chronic opiate users, there was a trend toward higher opiate requirements for the bupivacaine hydrochloride group than for the liposomal bupivacaine group; however, this trend did not achieve statistical significance.

CONCLUSIONS

Liposomal bupivacaine did not appear to significantly decrease perioperative narcotic use or length of hospitalization, although there was a trend toward decreased narcotic use in comparison with bupivacaine hydrochloride. While the results of this study do not support the routine use of liposomal bupivacaine, there may be a benefit in the subgroup of patients who are chronic opiate users. Future prospective randomized controlled trials, ideally with dose-response parameters, must be performed to fully explore the efficacy of liposomal bupivacaine, as the prior literature suggests that clinically relevant effects require a minimum tissue concentration.

Improved patient quality of life following intradural extramedullary spinal tumor resection

OBJECTIVE Resection significantly improves the clinical symptoms and functional outcomes of patients with intradural extramedullary tumors. However, patient quality of life following resection has not been adequately investigated. The aim in this retrospective analysis of prospectively collected quality of life outcomes is to analyze the efficacy of resection of intradural extramedullary spinal tumors in terms of quality of life markers. METHODS A retrospective review of a single institutional neurosurgical administrative database was conducted to analyze clinical data. The Oswestry Disability Index (ODI), visual analog scale (VAS) for pain, and the EQ-5D-3 L descriptive system were used to analyze quality of life preoperatively, less than 1 month postoperatively, 1-3 months postoperatively, 3-12 months postoperatively, and more than 12 months postoperatively. RESULTS The ODI scores increased perioperatively at the < 1-month follow-up from 36 preoperatively to 47. Relative to preoperative values, the ODI score decreased significantly at 1-3, 3-12, and > 12 months to 23, 17, and 20, respectively. VAS scores significantly decreased from 6.1 to 3.5, 2.4, 2.0, and 2.9 at the < 1-month, 1- to 3-, 3- to 12-, and > 12-month follow-ups, respectively. EQ-5D mobility significantly worsened at the < 1-month follow-up but improved at the 3- to 12-and > 12-month follow-ups. EQ-5D self-care significantly worsened at the < 1-month follow-up but significantly improved by the 3- to 12-month follow-up. EQ-5D usual activities improved at the 1- to 3-, 3- to 12-, and > 12-month follow-ups. EQ-5D pain and discomfort significantly improved at all follow-up points. EQ-5D anxiety and depression significantly improved at 1- to 3-month and 3- to 12-month follow-ups. CONCLUSIONS Resection of intradural extramedullary spine tumors appears to significantly improve patient quality of life by decreasing patient disability and pain and by improving each of the EQ-5D domains.

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

OBJECT

Unintended durotomy is a common occurrence during lumbar spinal surgery, particularly in surgery for degenerative spinal conditions, with the reported incidence rate ranging from 0.3% to 35%. The authors performed a systematic literature review on unintended lumbar spine durotomy, specifically aiming to identify the incidence of durotomy during spinal surgery for lumbar degenerative conditions. In addition, the authors analyzed the incidence of durotomy when minimally invasive surgical approaches were used as compared with that following a traditional midline open approach.

METHODS

A MEDLINE search using the term “lumbar durotomy” (under the 2015 medical subject heading [MeSH] “cerebrospinal fluid leak”) was conducted on May 13, 2015, for English-language medical literature published in the period from January 1, 2005, to May 13, 2015. The resulting papers were categorized into 3 groups: 1) those that evaluated unintended durotomy rates during open-approach lumbar spinal surgery, 2) those that evaluated unintended durotomy rates during minimally invasive spine surgery (MISS), and 3) those that evaluated durotomy rates in comparable cohorts undergoing MISS versus open-approach lumbar procedures for similar lumbar pathology.

RESULTS

The MEDLINE search yielded 116 results. A review of titles produced 22 potentially relevant studies that described open surgical procedures. After a thorough review of individual papers, 19 studies (comprising 15,965 patients) pertaining to durotomy rates during open-approach lumbar surgery were included for analysis. Using the Oxford Centre for Evidence-Based Medicine (CEBM) ranking criteria, there were 7 Level 3 prospective studies and 12 Level 4 retrospective studies. In addition, the authors also included 6 studies (with a total of 1334 patients) that detailed rates of durotomy during minimally invasive surgery for lumbar degenerative disease. In the MISS analysis, there were 2 prospective and 4 retrospective studies. Finally, the authors included 5 studies (with a total of 1364 patients) that directly compared durotomy rates during open-approach versus minimally invasive procedures. Studies of open-approach surgery for lumbar degenerative disease reported a total of 1031 durotomies across all procedures, for an overall durotomy rate of 8.11% (range 2%–20%). Prospectively designed studies reported a higher rate of durotomy than retrospective studies (9.57% vs 4.32%, p = 0.05). Selected MISS studies reported a total of 93 durotomies for a combined durotomy rate of 6.78%. In studies of matched cohorts comparing open-approach surgery with MISS, the durotomy rates were 7.20% (34 durotomies) and 7.02% (68), respectively, which were not significantly different.

CONCLUSIONS

Spinal surgery for lumbar degenerative disease carries a significant rate of unintended durotomy, regardless of the surgical approach selected by the surgeon. Interpretation of unintended durotomy rates for lumbar surgery is limited by a lack of prospective and cohort-matched controlled studies.

Complications from the use of intrawound vancomycin in lumbar spinal surgery: a systematic review

OBJECT

The use of intrawound vancomycin is rapidly being adopted for the prevention of surgical site infection (SSI) in spinal surgery. At operative closure, the placement of vancomycin powder in the wound bed—in addition to standard infection prophylaxis—can provide high concentrations of antibiotics with minimal systemic absorption. However, despite its popularity, to date the majority of studies on intrawound vancomycin are retrospective, and there are no prior reports highlighting the risks of routine treatment.

METHODS

A MEDLINE search for pertinent literature was conducted for studies published between 1966 and May 2015 using the following MeSH search terms: “intrawound vancomycin,” “operative lumbar spine complications,” and “nonoperative lumbar spine complications.” This was supplemented with references and known literature on the topic.

RESULTS

An advanced MEDLINE search conducted on May 6, 2015, using the search string “intrawound vancomycin” found 22 results. After a review of all abstracts for relevance to intrawound vancomycin use in spinal surgery, 10 studies were reviewed in detail. Three meta-analyses were evaluated from the initial search, and 2 clinical studies were identified. After an analysis of all of the identified manuscripts, 3 additional studies were included for a total of 16 studies. Fourteen retrospective studies and 2 prospective studies were identified, resulting in a total of 9721 patients. A total of 6701 (68.9%) patients underwent treatment with intrawound vancomycin. The mean SSI rate among the control and vancomycin-treated patients was 7.47% and 1.36%, respectively. There were a total of 23 adverse events: nephropathy (1 patient), ototoxicity resulting in transient hearing loss (2 patients), systemic absorption resulting in supratherapeutic vancomycin exposure (1 patient), and culture-negative seroma formation (19 patients). The overall adverse event rate for the total number of treated patients was 0.3%.

CONCLUSIONS

Intrawound vancomycin use appears to be safe and effective for reducing postoperative SSIs with a low rate of morbidity. Study disparities and limitations in size, patient populations, designs, and outcomes measures contribute significant bias that could not be fully rectified by this systematic review. Moreover, care should be exercised in the use of intrawound vancomycin due to the lack of well-designed, prospective studies that evaluate the efficacy of vancomycin and include the appropriate systems to capture drug-related complications.

Identification of complications that have a significant effect on length of stay after spine surgery and predictive value of 90-day readmission rate

OBJECT

Complications after spine surgery have an impact on overall outcome and health care expenditures. The increased cost of complications is due in part to associated prolonged hospital stays. The authors propose that certain complications have a greater impact on length of stay (LOS) than others and that those complications should be the focus of future targeted prevention efforts. They conducted a retrospective analysis of a prospectively maintained database to identify complications with the greatest impact on LOS as well as the predictive value of these complications with respect to 90-day readmission rates.

METHODS

Data on 249 patients undergoing spine surgery at Thomas Jefferson University from May to December 2008 were collected by a study auditor. Any complications occurring within 30 days of surgery were recorded as was overall LOS for each patient. Stepwise regression analysis was performed to determine whether specific complications had a statistically significant effect on LOS. For correlation, all readmissions within 90 days were recorded and organized by complication for comparison with those complications affecting LOS.

RESULTS

The mean LOS for patients without postoperative complications was 6.9 days. Patients who developed pulmonary complications had an associated increase in LOS of 11.1 days (p < 0.005). The development of a urinary tract infection (UTI) was associated with an increase in LOS of 3.4 days (p = 0.002). A new neurological deficit was associated with an increase in LOS of 8.2 days (p = 0.004). Complications requiring return to the operating room (OR) showed a trend toward an increase in LOS of 4.7 days (p = 0.09), as did deep wound infections (3.3 days, p = 0.08). The most common reason for readmission was for wound drainage (n = 21; surgical drainage was required in 10 [4.01%] of these 21 cases). The most common diagnoses for readmission, in decreasing order of incidence, were categorized as hardware malpositioning (n = 4), fever (n = 4), pulmonary (n = 2), UTI (n = 2), and neurological deficit (n = 1). Complications affecting LOS were not found to be predictive of readmission (p = 0.029).

CONCLUSIONS

Postoperative complications in patients who have undergone spine surgery are not uncommon and are associated with prolonged hospital stays. In the current cohort, the occurrence of pulmonary complications, UTI, and new neurological deficit had the greatest effect on overall LOS. Further study is required to determine the causative factors affecting readmission. These specific complications may be high-yield targets for cost reduction and/or prevention efforts.

Radiosurgery for Spinal Intramedullary Arteriovenous Malformations: A Literature Review

INTRODUCTION

Intramedullary spinal cord arteriovenous malformations (SCAVMs) comprise only 3 to 4% of spinal cord pathologies and are often not amenable to total resection due to extensive involvement with spinal cord parenchyma and multiple arterial feeding vessels.

METHODS

A electronic database search from 1966 to February 28, 2014, was conducted for relevant articles using the keywords and Medical Subject Headings strings spinal arteriovenous malformation, spinal radiosurgery, spinal vascular malformation, and radiosurgery for vascular lesions. Target outcomes measures were nidus obliteration, neurologic improvement, and complication rate.

RESULTS

Four retrospective articles containing a total of 30 patients were identified that described patients with SCAVMs presenting with symptomatic intramedullary or subarachnoid hemorrhage. Eighteen patients underwent treatment with CyberKnife with dosages ranging from 21 to 40 Gy (or a maximum biological equivalent dose of 58 Gy for early treatment effect) (Accuray, Inc., Sunnyvale, California, United States), 10 with a linear accelerator and real-time respiratory tracking ranging from 32 to 40 Gy, and 2 patients with external-beam radiotherapy receiving 45 Gy and 50 Gy, respectively. The mean time for clinical follow-up was 43.5 months (range: 27.9-60 months). There were no cases of spinal cord hemorrhage after radiosurgery. Nor were there any cases of neurologic worsening or signs and symptoms of neuropathic pain or myelitis. A total of 29 of the 30 patients obtained follow-up.

Simulation Training Curricula for Neurosurgical Residents: Cervical Foraminotomy and Durotomy Repair Modules

INTRODUCTION

Since 2010, the Congress of Neurological Surgeons (CNS) has offered a neurosurgical skills simulation course for residents and medical students. The authors describe their experience with incorporation of two neurosurgical skills simulation modules into the dedicated resident training curriculum of a single ACGME-accredited training program, using lumbar dural repair (5) and posterior cervical laminoforaminotomy modules from the CNS simulation initiative (6).

METHODS

Each of the available 22 neurosurgery residents at a single residency program was given two 20-question pretests for a cervical laminoforaminotomy and durotomy repair module as a basic test of regional anatomy, general disease knowledge, surgical decision making, and recently published literature. This was followed by a faculty-directed skills simulation course and concluded with a final 20 question post-test.

RESULTS

Posterior cervical laminoforaminotomy was performed once by each resident, and grading was conducted using the predetermined OSATs. The overall score was 56.1 (70%, range 26-76, maximum 80 points) with a trend towards higher scores with advanced levels of training. All residents completed the durotomy repair OSATs for a total of three trials. Of a maximum composite score of 60, a mean 37.2 (62%, range 15-58) was scored by the residents (Table 3). The mean OSAT scores for each durotomy trial was 2.66, 3.15, and 3.48 on each success test. A trend towards higher scores in advanced years of training was observed, but did not reach statistical significance (Figure 3).

CONCLUSIONS

Duty hour limitations and regulatory pressure for enhanced quality and outcomes may limit access of neurosurgical residents to fundamental skills training. Fundamental skills training as part of a validated simulation curriculum can mitigate this challenge to residency education. National development of effective technical simulation modules for use in individual residency training programs is a promising strategy to achieve these goals.

Timing in the surgical evacuation of spinal epidural abscesses

OBJECT

One often overlooked aspect of spinal epidural abscesses (SEAs) is the timing of surgical management. Limited evidence is available correlating earlier intervention with outcomes. Spinal epidural abscesses, once a rare diagnosis carrying a poor prognosis, are steadily becoming more common, with one recent inpatient meta-analysis citing an approximate incidence of 1 in 10,000 admissions with a mortality approaching 16%. One key issue of contention is the benefit of rapid surgical management of SEA to maximize outcomes. Timing of surgical management is definitely one overlooked aspect of care in spinal infections. Therefore, the authors performed a retrospective analysis in which they evaluated patients who underwent early (evacuation within 24 hours) versus delayed surgical intervention (> 24 hours) from the point of diagnosis, in an attempt to test the hypothesis that earlier surgery results in improved outcomes.

METHODS

A retrospective review of a prospectively maintained adult neurosurgical database from 2009 to 2011 was conducted for patients with the diagnostic heading: epidural abscess, infection, osteomyelitis, osteodiscitis, spondylodiscitis, and abscess. The primary end point for each patient was neurological grade, measured as an American Spinal Injury Association Impairment Scale grade using hospital inpatient records on admission and discharge. Patients were divided into early surgical (< 24 hours) and delayed surgical cohorts.

RESULTS

Eighty-seven consecutive patients were identified (25 females; mean age 55.5 years, age range 18-87 years). Fifty-four patients received surgery within 24 hours of admission (mean time from admission to incision, 11.2 hours), and 33 underwent surgery longer than 24 hours (mean 59 hours) after admission. Of the 54 patients undergoing early surgery 45 (85%) had a neurological deficit, whereas in the delayed surgical group 21 (64%) of 33 patients presented with a neurological deficit (p = 0.09). Patients in the delayed surgery cohort were significantly older by 10 years (59.6 vs 51.8 years, p = 0.01). With regard to history of prior revision, body mass index, intravenous drug abuse, tobacco use, prior radiation therapy, diabetes, chronic systemic infection, and prior osteomyelitis, there were no significant differences. There was no significant difference between early and delayed surgery groups in neurological grade on presentation, discharge, or location of epidural abscess. The most common organism isolated was Staphylococcus aureus (n = 51, 59.3%). The incidence of methicillin-resistant S. aureus was 21% (18 of 87).

CONCLUSIONS

Evacuation within 24 hours appeared to have a relative advantage over delayed surgery with regard to discharge neurological grade. However, due to a limited, variable sample size, a significant benefit could not be shown. Further subgroup analyses with larger populations are required.

C-5 palsy after cerebrospinal fluid diversion in posttraumatic syringomyelia: case report

Syringomyelia is a potentially debilitating disease that involves abnormal CSF flow mechanics; its incidence after traumatic spinal cord injury (SCI) is approximately 15%. Treatment consists of restoration of CSF flow, typically via arachnoidolysis and syrinx decompression. The authors present a case of pronounced syringomyelia in a patient with concomitant severe cervical myelomalacia to demonstrate unilateral C-5 palsy as a potential complication of aggressive syrinx decompression at a remote level. A 56-year-old man with a remote history of SCI at T-11 (ASIA [American Spinal Injury Association] Grade A) presented with complaints of ascending motor and sensory weakness into the bilateral upper extremities that had progressed over 1 year. MRI demonstrated severe distortion of the spinal cord at the prior injury level of T10-11, where an old anterior column injury and prior hook-rod construct was visualized. Of note, the patient had a holocord syrinx with demonstrable myelomalacia. To restore CSF flow and decompress the spinal cord, T-2 and T-3 laminectomies, followed by arachnoidolysis and syringopleural shunt placement, were performed. Postoperatively on Day 1, with the exception of a unilateral deltoid palsy, the patient had immediate improvement in upper-extremity strength and myelopathy. He was discharged from the hospital on postoperative Day 5; however, at his 2-week follow-up visit, a persistent unilateral deltoid palsy was noted. MRI demonstrated a significant reduction in the holocord syrinx, no neural foraminal stenosis, and a significant positional shift of the ventral spinal cord. Further motor recovery was noted at the 8-month follow-up. Syringomyelia is a debilitating disease arising most often as a result of traumatic SCI. In the setting of myelomalacia with a pronounced syrinx, C-5 palsy is a potential complication of syrinx decompression.

Biology of cerebral arteriovenous malformations with a focus on inflammation

Cerebral arteriovenous malformations (AVMs) entail a significant risk of intracerebral hemorrhage owing to the direct shunting of arterial blood into the venous vasculature without the dissipation of the arterial blood pressure. The mechanisms involved in the growth, progression and rupture of AVMs are not clearly understood, but a number of studies point to inflammation as a major contributor to their pathogenesis. The upregulation of proinflammatory cytokines induces the overexpression of cell adhesion molecules in AVM endothelial cells, resulting in enhanced recruitment of leukocytes. The increased leukocyte-derived release of metalloproteinase-9 is known to damage AVM walls and lead to rupture. Inflammation is also involved in altering the AVM angioarchitecture via the upregulation of angiogenic factors that affect endothelial cell proliferation, migration and apoptosis. The effects of inflammation on AVM pathogenesis are potentiated by certain single-nucleotide polymorphisms in the genes of proinflammatory cytokines, increasing their protein levels in the AVM tissue. Furthermore, studies on metalloproteinase-9 inhibitors and on the involvement of Notch signaling in AVMs provide promising data for a potential basis for pharmacological treatment of AVMs. Potential therapeutic targets and areas requiring further investigation are highlighted.

Technology and simulation to improve patient safety

Improving the quality and efficiency of surgical techniques, reducing technical errors in the operating suite, and ultimately improving patient safety and outcomes through education are common goals in all surgical specialties. Current surgical simulation programs represent an effort to enhance and optimize the training experience, to overcome the training limitations of a mandated 80-hour work week, and have the overall goal of providing a well-balanced resident education in a society with a decreasing level of tolerance for medical errors.

Correlation of posterior occipitocervical angle and surgical outcomes for occipitocervical fusion

Study Type Retrospective cohort study.

Introduction Craniocervical instability is a surgical disease, most commonly due to rheumatoid arthritis, trauma, erosive pathologies such as tumors and infection, and advanced degeneration. Treatment involves stabilization of the craniovertebral junction by occipitocervical instrumentation and fusion. However, the impact of the fixed occipitocervical angle on surgical outcomes, in particular the need for revision surgery and the incidence of dysphagia, remains unknown. Occipitocervical fusions (OCFs) at a single institution were reviewed to evaluate the relationships between postoperative neck alignment, the need for revision surgery, and dysphagia.

Objective The objective of this study is to determine whether an increased posterior occipital cervical angle results in an increase in the need for revision surgery, and secondary, dysphagia.

Methods A retrospective review of spinal surgery patients from January 2007 to June 2013 was conducted searching for patients who underwent an occipitocervical instrumented fusion utilizing diagnostic and procedural codes. Specifically, a current procedural code of 22590 (arthrodesis, posterior technique [craniocervical]) was queried, as well those with a description of “craniocervical” or “occipitocervical” arthrodesis. Ideal neck alignment before rod placement was judged by the attending surgeon. A review of all cases for revision surgery or evidence of dysphagia was then conducted.

Results From January 2007 to June 2013, 107 patients were identified (31 male, 76 female, mean age 63). Rheumatoid arthritis causing myelopathy was the most common indication for OCF, followed by trauma. Twenty of the patients were lost to follow-up and seven died within the perioperative period. Average follow-up for the remaining 80 patients was 16.4 months. The mean posterior occipitocervical angle (POCA), defined as the angle formed by the intersection of a line drawn tangential to the posterior aspect of the occipital protuberance and a line determined by the posterior aspect of the facets of the third and fourth cervical vertebrae, calculated after stabilization, was 107.1 degrees (range, 72–140 degrees). Reoperation was required in 11 patients (11/107, 10.3%). The mean POCA for the reoperation group was 109.5 degrees (range, 72–123) and was not significantly different than patients not requiring reoperation (106.5, p > 0.05). However, for all pathologies excluding infection as a cause for reoperation, the mean POCA was significantly higher, 115.14 degrees (p = 0.039) (Table 1). Seven patients (6.5%) complained of dysphagia postoperatively with a significantly higher POCA of 115 degrees (p = 0.039). Of these seven patients, six underwent posterior-only procedures. One patient underwent anterior and posterior procedures for a severe kyphotic deformity. The dysphagia resolved in six patients over a mean of 3 weeks (range, 2–4 weeks). One patient, whose surgery was posterior only, required the insertion of a gastrostomy tube.

Conclusions An elevated POCA may result in need for reoperation due to increased biomechanical stress upon adjacent segments or the construct itself due to flexion in an attempt to maintain forward gaze. Further, an elevated POCA seems to also correlate with a higher incidence of dysphagia. Further investigation is necessary to determine the ideal craniocervical angle which is likely individualized to a particular patient based on global and regional spinal alignments.

Comparison of techniques for ventriculoperitoneal shunting in 523 patients with subarachnoid hemorrhage

Object

It is common practice to use a new contralateral bur hole for ventriculoperitoneal shunt (VPS) placement in subarachnoid hemorrhage (SAH) patients with an existing ventriculostomy. At Thomas Jefferson University and Jefferson Hospital for Neuroscience, the authors have primarily used the ventriculostomy site for the VPS. The purpose of this study was to compare the safety of the 2 techniques in patients with SAH.

Methods

The rates of VPS-related hemorrhage, infection, and proximal revision were compared between the 2 techniques in 523 patients undergoing VPS placement (same site in 464 and contralateral site in 59 patients).

Results

The rate of new VPS-related hemorrhage was significantly higher in the contralateral-site group (1.7%) than in the same-site group (0%; p = 0.006). The rate of VPS infection did not differ between the 2 groups (6.4% for same site vs 5.1% for contralateral site; p = 0.7). In multivariate analysis, higher Hunt and Hess grades (p = 0.05) and open versus endovascular treatment (p = 0.04) predicted shunt infection, but the VPS technique was not a predictive factor (p = 0.9). The rate of proximal shunt revision was 6% in the same-site group versus 8.5% in the contralateralsite group (p = 0.4). In multivariate analysis, open surgery was the only factor predicting proximal VPS revision (p = 0.05).

Conclusions

The results of this study suggest that the use of the ventriculostomy site for VPS placement may be feasible and safe and may not add morbidity (infection or need for revision) compared with the use of a fresh contralateral site. This rapid and simple technique also was associated with a lower risk of shunt-related hemorrhage. While both techniques appear to be feasible and safe, a definitive answer to the question of which technique is superior awaits a higher level of medical evidence.

Saving the ischemic penumbra: endovascular thrombolysis versus medical treatment

Endovascular thrombolysis may allow rapid arterial recanalization in patients with acute ischemic stroke. We present the first study to our knowledge comparing the ischemic penumbra saved with endovascular versus medical therapy. A retrospective review of 21 patients undergoing endovascular intervention for stroke from 2010 to 2011 was contrasted with 21 consecutive patients treated with antiplatelet agents alone. Immediate computed tomography perfusion (CTP) scan of the head and neck was obtained in all patients. Patients with lacunar and posterior circulation infarcts, and those who were medically unstable for MRI post-operatively were excluded. CTP and MRI underwent volumetric calculation. CTP penumbra was correlated with diffusion restriction volumes on MRI, and an assessment was made on the volume of ischemic burden saved with either endovascular treatment or antiplatelet agents. The median age was 70 years (interquartile range 62-80). Median National Institutes of Health Stroke Scale score was 18 and 14 in the control and endovascular groups, respectively. Intravenous tissue plasminogen activator was administered in 22 of 42 patients (52%). Median penumbra calculated was 32,808 mm(3) in the control group and 46,255 mm(3) in the endovascular group. Median penumbra spared was 9550 mm(3) (4980-18,811) in the control group versus 38,155 mm(3) in the endovascular group (p=0.0001). Endovascular thrombolysis may be more efficient than medical therapy alone in saving ischemic penumbra. Future advances in recanalization techniques will further improve the efficacy of endovascular therapy.

Operative and nonoperative adverse events in the management of traumatic fractures of the thoracolumbar spine: a systematic review

Object

Thoracolumbar spine injuries are commonly encountered in patients with trauma, accounting for almost 90% of all spinal fractures. Thoracolumbar burst fractures comprise a high percentage of these traumatic fractures (45%), and approximately half of the patients with this injury pattern are neurologically intact. However, a debate over complication rates associated with operative versus nonoperative management of various thoracolumbar fracture morphologies is ongoing, particularly concerning those patients presenting without a neurological deficit.

Methods

A MEDLINE search for pertinent literature published between 1966 and December 2013 was conducted by 2 authors (G.G. and R.D.), who used 2 broad search terms to maximize the initial pool of manuscripts for screening. These terms were “operative lumbar spine adverse events” and “nonoperative lumbar spine adverse events.”

Results

In an advanced MEDLINE search of the term “operative lumbar spine adverse events” on January 8, 2014, 1459 results were obtained. In a search of “nonoperative lumbar spine adverse events,” 150 results were obtained. After a review of all abstracts for relevance to traumatic thoracolumbar spinal injuries, 62 abstracts were reviewed for the “operative” group and 21 abstracts were reviewed for the “nonoperative” group. A total of 14 manuscripts that met inclusion criteria for the operative group and 5 manuscripts that met criteria for the nonoperative group were included.

There were a total of 919 and 436 patients in the operative and nonoperative treatment groups, respectively. There were no statistically significant differences between the groups with respect to age, sex, and length of stay. The mean ages were 43.17 years in the operative and 34.68 years in the nonoperative groups. The majority of patients in both groups were Frankel Grade E (342 and 319 in operative and nonoperative groups, respectively). Among the studies that reported the data, the mean length of stay was 14 days in the operative group and 20.75 in the nonoperative group.

The incidence of all complications in the operative and nonoperative groups was 300 (32.6%) and 21 (4.8%), respectively (p = 0.1065). There was no significant difference between the 2 groups with respect to the incidence of pulmonary, thromboembolic, cardiac, and gastrointestinal complications. However, the incidence of infections (pneumonia, urinary tract infection, wound infection, and sepsis) was significantly higher in the operative group (p = 0.000875). The incidence of instrumentation failure and need for revision surgery was 4.35% (40 of 919), a significant morbidity, and an event unique to the operative category (p = 0.00396).

Conclusions

Due to the limited number of high-quality studies, conclusions related to complication rates of operative and nonoperative management of thoracolumbar traumatic injuries cannot be definitively made. Further prospective, randomized studies of operative versus nonoperative management of thoracolumbar and lumbar spine trauma, with standardized definitions of complications and matched patient cohorts, will aid in properly defining the risk-benefit ratio of surgery for thoracolumbar spine fractures.

Arachnolysis or cerebrospinal fluid diversion for adult-onset syringomyelia? A Systematic review of the literature

OBJECTIVE

To identify surgical practice patterns in the literature for nonpediatric syringomyelia by systematic review and to determine the following: 1) What is the best clinical practice of cerebrospinal fluid (CSF) diversion to maximize clinical improvement or to achieve the lowest recurrence rate? 2) Does arachnolysis, rather than CSF diversion, lead to prolonged times to clinical recurrence?

METHODS

A database search comprising PubMed, Cochrane Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and Cochrane Database of Systematic Reviews was conducted to find pertinent articles on postinfectious, posttraumatic, or idiopathic syringomyelia.

RESULTS

An advanced PubMed search in August 2012 yielded 1350 studies, including 12 studies meeting Oxford Centre for Evidence-Based Medicine criteria for level IV evidence as a case series, with a total of 410 patients (mean age, 39 years). Data on 486 surgeries were collected. Mean follow-up data were available for 10 studies, with a mean follow-up time of 62 months. On regression analysis, increased age had a significant correlation with a higher likelihood of having clinically significant recurrence on mean follow-up (P < 0.05). The use of arachnolysis in surgery was associated with a longer duration until clinically symptomatic recurrence (P = 0.02). Data on mortality were unavailable. The mean number of surgeries per patient across all studies was 1.20 (range, 0.95-2.00).

CONCLUSIONS

With postinfectious and posttraumatic etiologies, arachnolysis was the only surgical treatment to have a statistically significant effect on decreasing recurrence rates. More prospective, randomized, controlled studies are required to reach a clear consensus.

Efficacy of intraoperative vancomycin powder use in intrathecal baclofen pump implantation procedures: single institutional series in a high risk population

We aimed to assess the efficacy of intraoperative vancomycin powder in intrathecal baclofen pump placement patients, a high risk population. A retrospective review was conducted using prospectively collected data at an academic tertiary care unit. The neurosurgical adult patient population was queried for all intrathecal baclofen pump implantation procedures. Patients were then reviewed for the use of intraoperative crystalline vancomycin powder. Those with a history of prior surgical site infection, chronic systemic infections or osteomyelitis were excluded. Anhydrous, crystalline vancomycin was utilized in the wound bed after completion of implantation, distributed evenly in the case of multiple incisions. Patients received 500 mg or 1,000 mg of crystallized vancomycin, evenly distributed through the wound layers based on a 70 kg weight cutoff. Intraoperative institutional standards of infection prophylaxis were unchanged throughout the study period. Infection rate of baclofen pump placement prior to the use of vancomycin powder from 2001-2009 at the same institution was monitored. Wound infection rate was tracked for a 12 month postoperative period. Six patients out of 26 baclofen pump implantations (23%) in this cohort were identified to have seven infections despite vancomycin powder placement in the lumbar and catheter wounds. Prior infection rates have been investigated for intrathecal drug delivery systems from 2001 to 2009 at the same institution with an overall infection rate of 3% (8/274). The use of vancomycin powder in patients with implants in this series did not reduce infection rates compared to published historical controls, and was elevated compared to institutional controls. Further prospective study of this high risk patient population is warranted.

Evaluating initial spine trauma response: injury time to trauma center in PA, USA

Historical perceptions regarding the severity of traumatic spinal cord injury has led to considerable disparity in triage to tertiary care centers. This article retrospectively reviews a large regional trauma database to analyze whether the diagnosis of spinal trauma affected patient transfer timing and patterns. The Pennsylvania Trauma database was retrospectively reviewed. All acute trauma patient entries for level I and II centers were categorized for diagnosis, mechanism, and location of injury, analyzing transportation modality and its influence on time of arrival. A total of 1162 trauma patients were identified (1014 blunt injuries, 135 penetrating injuries and 12 other) with a mean transport time of 3.9 hours and a majority of patients arriving within 7 hours (>75%). Spine trauma patients had the longest mean arrival time (5.2 hours) compared to blunt trauma (4.2 hours), cranial neurologic injuries (4.35 hours), and penetrating injuries (2.13 hours, p<0.0001). There was a statistically significant correlation between earlier arrivals and both cranial trauma (p=0.0085) and penetrating trauma (p<0.0001). The fastest modality was a fire rescue (0.93 hours) or police (0.63 hours) vehicle with Philadelphia County (1.1 hour) having the quickest arrival times. Most trauma patients arrived to a specialty center within 7 hours of injury. However subsets analysis revealed that spine trauma patients had the greatest transit times. Present research trials for spinal cord injuries suggest earlier intervention may lead to improved recovery. Therefore, it is important to focus on improvement of the transportation triage system for traumatic spinal patients.

Simulated lumbar minimally invasive surgery educational model with didactic and technical components

BACKGROUND

The learning and development of technical skills are paramount for neurosurgical trainees. External influences and a need for maximizing efficiency and proficiency have encouraged advancements in simulator-based learning models.

OBJECTIVE

To confirm the importance of establishing an educational curriculum for teaching minimally invasive techniques of pedicle screw placement using a computer-enhanced physical model of percutaneous pedicle screw placement with simultaneous didactic and technical components.

METHODS

A 2-hour educational curriculum was created to educate neurosurgical residents on anatomy, pathophysiology, and technical aspects associated with image-guided pedicle screw placement. Predidactic and postdidactic practical and written scores were analyzed and compared. Scores were calculated for each participant on the basis of the optimal pedicle screw starting point and trajectory for both fluoroscopy and computed tomographic navigation.

RESULTS

Eight trainees participated in this module. Average mean scores on the written didactic test improved from 78% to 100%. The technical component scores for fluoroscopic guidance improved from 58.8 to 52.9. Technical score for computed tomography-navigated guidance also improved from 28.3 to 26.6.

CONCLUSION

Didactic and technical quantitative scores with a simulator-based educational curriculum improved objectively measured resident performance. A minimally invasive spine simulation model and curriculum may serve a valuable function in the education of neurosurgical residents and outcomes for patients.

Simulated spinal cerebrospinal fluid leak repair: an educational model with didactic and technical components

BACKGROUND

In the era of surgical resident work hour restrictions, the traditional apprenticeship model may provide fewer hours for neurosurgical residents to hone technical skills. Spinal dura mater closure or repair is 1 skill that is infrequently encountered, and persistent cerebrospinal fluid leaks are a potential morbidity.

OBJECTIVE

To establish an educational curriculum to train residents in spinal dura mater closure with a novel durotomy repair model.

METHODS

The Congress of Neurological Surgeons has developed a simulation-based model for durotomy closure with the ongoing efforts of their simulation educational committee. The core curriculum consists of didactic training materials and a technical simulation model of dural repair for the lumbar spine.

RESULTS

Didactic pretest scores ranged from 4/11 (36%) to 10/11 (91%). Posttest scores ranged from 8/11 (73%) to 11/11 (100%). Overall, didactic improvements were demonstrated by all participants, with a mean improvement between pre- and posttest scores of 1.17 (18.5%; P = .02). The technical component consisted of 11 durotomy closures by 6 participants, where 4 participants performed multiple durotomies. Mean time to closure of the durotomy ranged from 490 to 546 seconds in the first and second closures, respectively (P = .66), whereby the median leak rate improved from 14 to 7 (P = .34). There were also demonstrative technical improvements by all.

CONCLUSION

Simulated spinal dura mater repair appears to be a potentially valuable tool in the education of neurosurgery residents. The combination of a didactic and technical assessment appears to be synergistic in terms of educational development.

Research in spinal surgery: Evaluation and practice of evidence-based medicine

Evidence-based medicine (EBM) is a common concept among medical practitioners, yet unique challenges arise when EBM is applied to spinal surgery. Due to the relative rarity of certain spinal disorders, and a lack of management equipoise, randomized controlled trials may be difficult to execute. Despite this, responsibility rests with spinal surgeons to design high quality studies in order to justify certain treatment modalities. The authors therefore review the tenets of implementing evidence-based research, through the lens of spinal disorders. The process of EBM begins with asking the correct question. An appropriate study is then designed based on the research question. Understanding study designs allows the spinal surgeon to assess the level of evidence provided. Validated outcome measurements allow clinicians to communicate the success of treatment strategies, and will increase the quality of a given study design. Importantly, one must recognize that the randomized controlled trial is not always the optimal study design for a given research question. Rather, prospective observational cohort studies may be more appropriate in certain circumstances, and would provide superior generalizability. Despite the challenges involved with EBM, it is the future of medicine. These issues surrounding EBM are important for spinal surgeons, as well as health policy makers and editorial boards, to have familiarity.

En bloc resection of upper thoracic chordoma via a combined simultaneous anterolateral thoracoscopic and posterior approach

BACKGROUND

En bloc resection of chordomas is associated with increased patient survival. Achievement of en bloc resection, however, may present a great surgical challenge, particularly in the mobile spine. Novel multidisciplinary techniques may enable en bloc resection of lesions presenting in anatomically challenging locations. A combined simultaneous thoracoscopic and posterior approach in a patient with an upper thoracic chordoma is presented; en bloc resection was achieved.

OBJECTIVE

To show the feasibility, safety, and utility of performing a thoracoscopy-assisted en bloc resection of a chordoma involving the upper thoracic spine.

METHODS

A case study is presented of a patient with biopsy-proven chordoma of T2-3 with predominantly paravertebral involvement who underwent multilevel en bloc resection via a simultaneous combined anterolateral thoracoscopic and posterior approach. Thoracoscopic assistance achieved separation of the tumor and ventral spine from the adjacent mediastinal structures. En bloc resection proceeded without complication. The spine was stabilized with posterior instrumentation.

RESULTS

A multilevel en bloc resection was achieved with negative margins, preserving more than half of the remaining vertebral bodies and allowing short segment posterior fixation without extension into the cervical spine. The patient remained neurologically intact.

CONCLUSION

A combined simultaneous thoracoscopic and posterior approach is safe and effective for en bloc resection of multilevel chordoma involving the upper thoracic spine. This technique allows for a plane to be established ventrally between the tumor and the mediastinum, thus assisting with safe osteotomies via the posterior approach.

ASA grade and Charlson Comorbidity Index of spinal surgery patients: correlation with complications and societal costs

BACKGROUND CONTEXT

The Charlson Comorbidity Index (CCI) and the American Society of Anesthesiologists (ASA) Physical Status Classification System (ASA grade) are useful for predicting morbidity and mortality for a variety of disease processes.

PURPOSE

To evaluate CCI and ASA grade as predictors of complications after spinal surgery and examine the correlation between these comorbidity indices and the cost of care.

STUDY DESIGN/SETTING

Prospective observational study.

PATIENT SAMPLE

All patients undergoing any spine surgery at a single academic tertiary center over a 6-month period.

OUTCOME MEASURES

Direct health-care costs estimated from diagnosis related group and Current Procedural Terminology (CPT) codes.

METHODS

Demographic data, including all patient comorbidities, procedural data, and all complications, occurring within 30 days of the index procedure were prospectively recorded. Charlson Comorbidity Index was calculated from International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes and ASA grades determined from the operative record. Diagnosis related group and CPT codes were captured for each patient. Direct costs were estimated from a societal perspective using Medicare rates of reimbursement. A multivariable analysis was performed to assess the association of the CCI and ASA grade to the rate of complication and direct health-care costs.

RESULTS

Two hundred twenty-six cases were analyzed. The average CCI score for the patient cohort was 0.92, and the average ASA grade was 2.65. The CCI and ASA grade were significantly correlated, with Spearman ρ of 0.458 (p<.001). Both CCI and ASA grade were associated with increasing body mass index (p<.01) and increasing patient age (p<.0001). Increasing CCI was associated with an increasing likelihood of occurrence of any complication (p=.0093) and of minor complications (p=.0032). Increasing ASA grade was significantly associated with an increasing likelihood of occurrence of a major complication (p=.0035). Increasing ASA grade showed a significant association with increasing direct costs (p=.0062).

CONCLUSIONS

American Society of Anesthesiologists and CCI scores are useful comorbidity indices for the spine patient population, although neither was completely predictive of complication occurrence. A spine-specific comorbidity index, based on ICD-9-CM coding that could be easily captured from patient records, and which is predictive of patient likelihood of complications and mortality, would be beneficial in patient counseling and choice of operative intervention.

Preoperative spinal tumor embolization: an institutional experience with Onyx

BACKGROUND

Preoperative embolization has the potential to decrease intraoperative blood loss and facilitate spinal cord decompression and tumor resection.

OBJECTIVE

We report our institutional experience with the embolization of hypervascular extradural spinal tumors with Onyx as well as earlier embolic agents in a series of 28 patients.

METHODS

A retrospective case review was conducted on patients undergoing preoperative transarterial embolization of a spinal tumor between 1995 and 2012 at our institution.

RESULTS

Twenty-eight patients met the inclusion criteria, with a mean age of 60.6 years. Twenty-eight patients had metastatic tumors. In 14 (50%) patients the metastases were from renal cell carcinomas. Fifty-four vessels were embolized using PVA, NBCA, Onyx, coils, or embospheres. Sixteen patients were treated with Onyx, 6 patients with PVA, 3 patients with embospheres, 2 patients with NBCA, and 3 patients with a combination of embolic agents. The average decrease in tumor blush was 97.8% with Onyx versus 92.7% with the rest of the embolic agents (p=0.08). The estimated blood loss was 1616ml (range 350-5000ml). Blood loss was 750cm(3) on average with Onyx versus 1844 with the rest of the embolic agents (p=0.14). The mean length of stay was 16 days. The mortality rate was zero. Pre- and post-operative modified Rankin Score (mRS) did not differ significantly in the series (3.12 versus 3.10, respectively, p=0.9).

CONCLUSION

In our experience, the use of transarterial tumor embolization as an adjunct for spinal surgery is a safe and feasible option.

Neurosurgical Training With a Novel Cervical Spine Simulator

BACKGROUND:

Neurosurgical residents have traditionally been instructed on surgical techniques and procedures through an apprenticeship model. Currently, there has been research and interest in expanding the neurosurgical education model.

OBJECTIVE:

To establish a posterior cervical decompression educational curriculum with a novel cervical simulation model.

METHODS:

The Congress of Neurological Surgeons developed a simulation committee to explore and develop simulation-based models. The educational curriculum was developed to have didactic and technical components with the incorporation of simulation models. Through numerous reiterations, a posterior cervical decompression model was developed and a 2-hour education curriculum was established.

RESULTS:

Individual's level of training varied, with 5 postgraduate year (PGY) 2 participants, 1 PGY-3 participant, 2 PGY-5 participants, and 1 attending, with the majority being international participants (6 of 9, 67%). Didactic scores overall improved (7 of 9, 78%). The technical scores of all participants improved from 11 to 24 (mean, 14.1) to 19 to 25 (mean, 22.4). Overall, in the posterior cervical decompression simulator, there was a significant improvement in the didactic scores (P = .005) and the technical scores (P = .02).

CONCLUSION:

The posterior cervical decompression simulation model appears to be a valuable tool in educating neurosurgery residents in the aspects of this procedure. The combination of a didactic and technical assessment is a useful teaching strategy in terms of educational development.

Simulated Lumbar Minimally Invasive Surgery Educational Model With Didactic and Technical Components

BACKGROUND:

The learning and development of technical skills are paramount for neurosurgical trainees. External influences and a need for maximizing efficiency and proficiency have encouraged advancements in simulator-based learning models.

OBJECTIVE:

To confirm the importance of establishing an educational curriculum for teaching minimally invasive techniques of pedicle screw placement using a computer-enhanced physical model of percutaneous pedicle screw placement with simultaneous didactic and technical components.

METHODS:

A 2-hour educational curriculum was created to educate neurosurgical residents on anatomy, pathophysiology, and technical aspects associated with image-guided pedicle screw placement. Predidactic and postdidactic practical and written scores were analyzed and compared. Scores were calculated for each participant on the basis of the optimal pedicle screw starting point and trajectory for both fluoroscopy and computed tomographic navigation.

RESULTS:

Eight trainees participated in this module. Average mean scores on the written didactic test improved from 78% to 100%. The technical component scores for fluoroscopic guidance improved from 58.8 to 52.9. Technical score for computed tomography—navigated guidance also improved from 28.3 to 26.6.

CONCLUSION:

Didactic and technical quantitative scores with a simulator-based educational curriculum improved objectively measured resident performance. A minimally invasive spine simulation model and curriculum may serve a valuable function in the education of neurosurgical residents and outcomes for patients.