The impact of incidental durotomy on the outcome of decompression surgery in degenerative lumbar spinal canal stenosis: analysis of the Lumbar Spinal Outcome Study (LSOS) data--a Swiss prospective multi-center cohort study

Incidental dural tears do not affect the overall patients' reported outcome of spine surgery at long-term follow-up: results of a systematic review

To conduct a systematic review of the literature in order to establish if there is an overall adverse effect of accidental durotomy on the long-term patients' reported outcome after elective spine surgery. A systematic literature search was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data about pre- and postoperative clinical outcomes of patients with accidental durotomy and patients without were extracted and analysed. After screening, eleven studies were included with a total of 80,541 patients. About 4112 of these patients (5.10%) had incidental dural tear. When comparing patients with dural tear to patients without, 9/11 authors found no patients' reported differences at last follow-up. One author found a slightly worse VAS back pain in dural tear patients, and another author found inferior SF-36 and ODI scores in dural tear patients (both below minimal clinically important difference). Accidental dural tear did not have a significant adverse effect on clinical outcome of elective spine surgery. More studies are needed to better demonstrate this result.

Initial experience of 3-dimensional exoscope in decompression of massive lumbar disc herniation

OBJECTIVES

To investigate the effect of a three-dimensional (3D) exoscope for decompression of single-segment massive lumbar disc herniation (LDH).

METHODS

The study included 56 consecutive patients with single segment massive LDH who underwent decompression assisted by a 3D exoscope from October 2019 to October 2022 at a university hospital. The analysis was based on comparison of perioperative metrics including decompression time, estimated blood loss (EBL) during decompression and postoperative length of stay (PLS); clinical outcomes including assessment using the visual analogue scale (VAS) and the Oswestry disability index (ODI); and incidence of reoperation and complications.

RESULTS

The mean decompression time was 28.35 ± 8.93 min (lumbar interbody fusion (LIF)) and 15.50 ± 5.84 min (fenestration discectomy (LOVE surgery)), the mean EBL during decompression was 42.65 ± 12.42 ml (LIF) and 24.32 ± 8.61 ml (LOVE surgery), and the mean PLS was 4.56 ± 0.82 days (LIF) and 2.00 ± 0.65 days (LOVE surgery). There were no complications such as cerebrospinal fluid leakage, nerve root injury and epidural hematoma. All patients who underwent decompression assisted by a 3D exoscope were followed up for 6 months. At the last follow-up, the VAS and ODI scores were significantly improved from the preoperative period to the last follow-up (P < 0.05).

CONCLUSIONS

A 3D exoscope provides a visually detailed, deep and clear surgical field, which makes decompression safer and more effective and reduces short-term complications. A 3D exoscope may be a good assistance tool during decompression for single-segment massive LDH.

Effectiveness and safety of interspinous spacer versus decompressive surgery for lumbar spinal stenosis: A meta-analysis of randomized controlled trials

STUDY DESIGN

A meta-analysis of randomized controlled trials.

OBJECTIVE

Our meta-analysis was conducted to investigate whether interspinous spacer (IS) results in better performance for patients with lumbar spinal stenosis (LSS) when compared with decompressive surgery (DS).

BACKGROUND DATA

DS and IS are common surgeries for the treatment of LSS. However, controversy remains as to whether the IS is superior to DS.

METHODS

We comprehensively searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials for prospective randomized controlled trials that compared IS versus DS for LSS. The retrieved results were last updated on July 30, 2023.

RESULTS

Eight studies involving 852 individuals were included in the meta-analysis. The pooled data indicated that IS was superior to DS considering shorter operation time (P = .003), lower dural violation rate (P = .002), better Zurich Claudication Questionnaire Physical function score (P = .03), and smaller foraminal height decrease (P = .004), but inferior to DS considering the higher rate of reoperation (P < .0001). There was no significant difference between the 2 groups regarding hospital stay (P = .26), blood loss (P = .23), spinous process fracture (P = .09), disc height decrease (P = .87), VAS leg pain score (P = .43), VAS back pain score (P = .26), Oswestry Disability Index score (P = .08), and Zurich Claudication Questionnaire symptom severity (P = .50).

CONCLUSIONS

In summary, we considered that IS had similar effects with DS in hospital stay, blood loss, spinous process fracture, disc height decrease, VAS score, Oswestry Disability Index score, and Zurich Claudication Questionnaire Symptom severity, and was better in some indices such as operation time, dural violation, Zurich Claudication Questionnaire Physical function, and foraminal height decrease than DS. However, due to the higher rate of reoperation in the IS group, we considered that both IS and DS were acceptable strategies for treating LSS. As a novel technique, further well-designed studies with longer-term follow-up are needed to evaluate the effectiveness and safety of IS.

Outcomes of Incidental Durotomy Repair in Thoracolumbar Spine Surgery: An Institutional Experience With Orthopedic Residents

Background The occurrence of incidental durotomies (IDs) following spinal operations is a widely recognized issue. Complications such as poor outcomes, extended hospitalization, prolonged immobilization, infections, and revision surgeries are all potential consequences of inadequate durotomy management during the initial surgery. This study aims to describe the outcomes of ID repair in thoracolumbar spine surgery in terms of the Oswestry Disability Index (ODI) score and visual analog scale (VAS) when performed with the active involvement of orthopedic residents in the surgical procedure. Methodology Between April 2021 and April 2023, a hospital-based observational study was conducted among 110 patients hospitalized in the orthopedic ward at R.L. Jalappa Hospital and Research Center in Kolar, Karnataka, who required IDs due to an accidental dural tear or a postoperative CSF fluid leak following thoracolumbar spine procedures. Patients with a previous history of thoracolumbar spine surgery, vertebral tumors, spinal metastasis, infections, e.g., spondylodiscitis, or Pott's spine were excluded. The ODI score and VAS score were calculated on the postoperative day, one month, and three months following surgery. Results The mean age of the study participants was 62.81 + 10.49 years, with a male preponderance of 67.2% among the study participants. The mean BMI of study participants was 23.77 kg/m2. Approximately 24.5% of participants had a prior history of spinal surgery. Among 110 patients, 32 had postoperative complications. Six patients reported experiencing urinary retention, followed by five with CSF leakage and one with a postural headache (five cases). Based on the ODI score, mild disability was seen in 32.7% of the study samples at three months of follow-up. Based on the VAS score, moderate pain was seen among all the study samples at three months of follow-up. The ANOVA test revealed statistically significant differences in ODI and VAS score reductions between the immediate postoperative period and the one-month and three-month follow-up periods (p = 0.001 and p = 0.0247, respectively). Conclusion Less than one-third of the samples had postoperative complications. At three months, ODI scores showed mild disability in one-third of the study samples. At three months, all study samples had moderate VAS pain. The improvement in ODI and VAS scores from the day after surgery through the one-month and three-month follow-up periods was statistically significant.

Incidental dural tears associated with worse clinical outcomes in patients operated for lumbar spinal stenosis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Incidental dural (ID) tear is a common complication of spine surgery with a prevalence of 4-10%. The association between ID and clinical outcome is uncertain. Former studies found only minor differences in Oswestry Disability Index (ODI). We aimed to examine the association of ID with treatment failure after surgery for lumbar spinal stenosis (LSS).

METHODS

Between 2007 and 2017, 11,873 LSS patients reported to the national Norwegian spine registry (NORspine), and 8,919 (75.1%) completed the 12-month follow-up. We used multivariate logistic regression to study the association between ID and failure after surgery, defined as no effect or any degrees of worsening; we also compared mean ODI between those who suffered a perioperative ID and those who did not.

RESULTS

The mean (95% CI) age was 66.6 (66.4-66.9) years, and 52% were females. The mean (95% CI) preoperative ODI score (95% CI) was 39.8 (39.4-40.1); all patients were operated on with decompression, and 1125 (12.6%) had an additional fusion procedure. The prevalence of ID was 4.9% (439/8919), and the prevalence of failure was 20.6% (1829/8919). Unadjusted odds ratio (OR) (95% CI) for failure for ID was 1.51 (1.22-1.88); p < 0.001, adjusted OR (95% CI) was 1.44 (1.11-1.86); p = 0.002. Mean postoperative ODI 12 months after surgery was 27.9 for ID vs. 23.6 for no ID.

CONCLUSION

We demonstrated a significant association between ID and increased odds for patient-reported failure 12 months after surgery. However, the magnitude of the detrimental effect of ID on the clinical outcome was small.

Investigating acetazolamide effectiveness on CSF leak in adult patients after spinal surgery

INTRODUCTION AND OBJECTIVES

Despite the use of acetazolamide in the management of CSF leak in most patients after CNS surgeries, there is scant evidence in the literature about the efficacy of this established protocol among adult patients in post-spinal surgery observations. We investigated the potential positive effect of acetazolamide in reducing CSF leak after spine surgery.

MATERIALS AND METHODS

We conducted a single-center, double-blind, randomized -controlled trial comparing Oral Acetazolamide plus Corrected body (prone) position (CP+A) versus Corrected body (prone) position alone (CP-A) from January 2014 to September 2015 in the Neurosurgery ward of Shariati Teaching Hospital, Tehran University of Medical Sciences, Tehran, Iran. Seventy-two Patients divided into two groups [CP-A group (n = 36, 50%) and CP+A group (n = 36, 50%)] were randomly assigned to this Clinical Trial study. CP+A group (maintained the 3/4 lateral position + dose of acetazolamide 20 mg/kg/day in 3-4 divided doses for 7 days), and CP-A group (Control group) (maintained the 3/4 lateral position for 7 days with no acetazolamide).

RESULTS

Baseline characteristics between the two groups showed no significant differences: Sex (P < .637), Age (P < .988) and previous CNS operation at other location besides the spine (P < .496). Although we reported post-surgical CSF leak in 2/36 (5.55%) of CP+A group and 4/36 (11.11%) of CP-A (control) group, there was no significant difference observed between the two groups (95%CI, 0.081-2.748; OR = 0.471; P < .402; Adjusted P < .247). Additionally, no significant differences were observed when we examined surgical characteristics, such as the size of the dural opening (P < .489) and type of operation (P < .465).

CONCLUSION

Acetazolamide has no positive effect in controlling CSF leak after dural opening/dural tear in adult patients who undergo spinal surgery, when we considered alongside the one-week prone position. Therefore, acetazolamide administration may not be essential for postoperative spinal surgery for dural tear. Prospective studies involving a larger sample size may be needed to track long-term acetazolamide complications on patients with CSF leak.

Lumbar spinal stenosis - surgical outcome and the odds of revision-surgery: Is it all due to the surgeon?

BACKGROUND

Surgical decompression is the intervention of choice for lumbar spinal stenosis (LSS) when non-operative treatment has failed. Apart from acute complications such as hematoma and infections, same-level recurrent lumbar stenosis and adjacent-segment disease (ASD) are factors that can occur after index lumbar spine surgery.

OBJECTIVE

The aim of this retrospective case series was to evaluate the outcome of surgery and the odds of necessary revisions.

METHODS

Patients who had undergone either decompressive lumbar laminotomy or laminotomy and spinal fusion due to lumbar spinal stenosis (LSS) between 2000 and 2011 were included in this analysis. Demographic, perioperative and radiographic data were collected. Clinical outcome was evaluated using numeric rating scale (NRS), the symptom subscale of the adapted version of the german Spinal Stenosis Measure (SSM) and patient-sreported ability to walk.

RESULTS

Within the LSS- cohort of 438 patients, 338 patients underwent decompression surgery only, while instrumentation in addition to decompression was performed in 100 cases (22.3%). 38 patients had prior spinal operations (decompression, disc herniation, fusion) either at our hospital or elsewhere. Thirty-five intraoperative complications were documented with dural tear with CSF leak being the most common (33/35; 94.3%). Postoperative complications were defined as complications that needed surgery and differentiated between immediate postoperative complications (⩽ 3 weeks post operation) and complications that needed revisions surgery at a later date. Within all patients 51 revisions were classified as immediate complications of the index operation with infections, neurological deficits and hematoma being the most common. Within this group only 22 patients had fusion surgery in the first place, while 29 were treated by decompression. Revision surgery was indicated by 53 patients at a later date. While 4 patients decided against surgery, 49 revision surgeries were planned. 28 were performed at the same level, 10 at the same level plus an adjacent level, and 10 were executed at index level with indications of adjacent level spinal stenosis, adjacent level spinal stenosis plus instability and stand-alone instability. Pre- operative VAS score and ability to walk improved significantly in all patients.

CONCLUSIONS

While looking for predictors of revision surgery due to re-stenosis, instability or same/adjacent segment disease none of these were found. Within our cohort no significant differences concerning demographic, peri-operative and radiographic data of patients with or without revision wer noted. Patients, who needed revision surgery were older but slightly healthier while more likely to be male and smoking. Surprisingly, significant differences were noted regarding the distribution of intraoperative and early postoperative complications among the 6 main surgeons while these weren't obious within the intial index group of late revisions.

Microendoscopic Lumbar Posterior Decompression Surgery for Lumbar Spinal Stenosis: Literature Review

Lumbar spinal stenosis (LSS) is a common disease in the elderly, mostly due to degenerative changes in the lumbar spinal complex. Decompression surgery is the standard surgical treatment for LSS. Classically, total laminectomy—which involves resection of the spinous process, entire laminae and medial facet—has been the standard decompression technique; however, it can cause post-surgical instability. To overcome this disadvantage, various minimally invasive techniques that preserve the stabilization structures of the spine have been developed, and surgeons have begun to re-evaluate decompression surgery from the standpoint of reduced invasiveness and cost. More than two decades have passed since the introduction of microendoscopic spine surgery, and studies continue to shed light on its advantages and limitations as new knowledge becomes available. This article is a narrative review of the available literature, along with authors’ experience, regarding the indications, surgical techniques, clinical outcomes, and limitations/complications of microendoscopic decompression for LSS.

Sacral Insufficiency Fracture Following Short-Segment Lumbosacral Fusion: Case Series and Review of the Literature

STUDY DESIGN

Retrospective case series.

OBJECTIVE

Sacral insufficiency fracture is a rare and serious complication following lumbar spine instrumented fusion. The purpose of this study was to describe the patient characteristics, presentation, evaluation, treatment options, and outcomes for patients with sacral insufficiency fracture after short-segment lumbosacral fusion.

METHODS

Six patients from our institutional database and 16 patients from literature review were identified with a sacral insufficiency fracture after short-segment (L4-S1 or L5-S1) lumbar fusion within 1 year of surgery.

RESULTS

Patients were 55% female with a mean age of 58 years and body mass index of 30 kg/m². Osteoporosis or osteopenia was the most common comorbidity (85%). Half of patients sustained a sacral fracture after surgery from a posterior approach, while the others had anterior or anterior-posterior surgery. Mean time to fracture was 42 days with patients clinically presenting with new sacral pain (86%), radiculopathy (60%), or neurologic deficit (5%). Ultimately, 73% of patients underwent operative fixation often involving extension of the construct (75%) and fusion to the pelvis (69%). Men (P = .02) and patients with new radicular pain or neurologic deficit (P = .01) were more likely to undergo revision surgical treatment while women over 50 years of age were more likely to be treated conservatively (P = .003).

CONCLUSIONS

Spine surgeons should monitor for sacral insufficiency fracture as a source of new-onset pain in the postoperative period in patients with a short segment fusion to the sacrum. The recognition of this complication should prompt an assessment of bone health and management of underlying bone fragility.

Association between depression and anxiety on symptom and function after surgery for lumbar spinal stenosis

Evidence on the role of depression and anxiety in patients undergoing surgical treatment for symptomatic degenerative lumbar spinal stenosis (DLSS) is conflicting. We aimed to assess the association between depression and anxiety with symptoms and function in patients undergoing surgery for DLSS. Included were patients with symptomatic DLSS participating in a prospective multicentre cohort study who underwent surgery and completed the 24-month follow-up. We used the hospital anxiety and depression scale (HADS) to assess depression/anxiety. We used mixed-effects models to quantify the impact on the primary outcome change in the spinal stenosis measure (SSM) symptoms/function subscale from baseline to 12- and 24-months. Logistic regression analysis was used to quantify the odds of the SSM to reach a minimal clinically important difference (MCID) at 24 months follow-up. The robustness of the results in the presence of unmeasured confounding was quantified using a benchmarking method based on a multiple linear model. Out of 401 patients 72 (17.95%) were depressed and 80 anxious (19.05%). Depression was associated with more symptoms (β = 0.36, 95% confidence interval (CI) 0.20 to 0.51, p < 0.001) and worse function (β = 0.37, 95% CI 0.24 to 0.50, p < 0.001) at 12- and 24-months. Only the association between baseline depression and SSM symptoms/function was robust at 12 and 24 months. There was no evidence for baseline depression/anxiety decreasing odds for a MCID in SSM symptoms and function over time. In patients undergoing surgery for symptomatic DLSS, preoperative depression but not anxiety was associated with more severe symptoms and disability at 12 and 24 months.

Wide Laminectomy, Segmental Bilateral Laminotomies, or Unilateral Hemi-Laminectomy for Lumbar Spinal Stenosis: Five-year Patient-reported Outcomes in Propensity-matched Cohorts

STUDY DESIGN

Propensity-matched retrospective study of patients prospectively enrolled in Danespine.

OBJECTIVE

The aim of this study was to report 5-year patient reported outcome in lumbar spinal stenosis (LSS) patients who underwent wide laminectomy (WL), segmental bilateral laminotomies (SBL), or unilateral hemilaminectomy (UHL) with bilateral decompression.

SUMMARY OF BACKGROUND DATA

The optimal procedure for LSS remains controversial. Studies have shown no difference in short term outcomes among micro-laminectomy, hemi-laminotomies, broad laminectomy, and laminectomy with instrumented fusion.

METHODS

Patients with spinal stenosis who were enrolled in DaneSpine at two spine centers from January 2010 until May 2014 and underwent WL0, SBL, or UHL with bilateral decompression were identified. Patients completed standard questionnaires preoperatively and 1, 2, and 5 years after surgery. Patients in the three cohorts were propensity-matched using age, sex, body mass index (BMI), smoking status, number of surgical levels, American Society of Anesthesiologists (ASA) score, and patient-reported outcome measures (PROMs).

RESULTS

Propensity matching produced 62 cases in each group. There were no differences in PROM among the three cohorts at five years follow up. Twelve patients were re-operated at the index level. The most frequent indication of reoperation was repeat decompression after SBL. Regression analysis revealed no statistical significant associations between the incidence of reoperation and age, sex, number of operated levels, ASA score, BMI, center, smoking status, or having a dural tear at index operation.

CONCLUSION

This study revealed no significant difference PROMs, reoperation rates or time to reoperation at five years follow up between SBLs, UHL, or WL in patients operated for central LSS.Level of Evidence: 4.

Accidental Dural Tears in Minimally Invasive Spinal Surgery for Degenerative Lumbar Spine Disease

Background: One of the most frequent complications of spinal surgery is accidental dural tears (ADTs). Minimal access surgical techniques (MAST) have been described as a promising approach to minimizing such complications. ADTs have been studied extensively in connection with open spinal surgery, but there is less literature on minimally invasive spinal surgery (MISS).

Materials and Methods: We reviewed 187 patients who had undergone degenerative lumbar spinal surgery using minimally invasive spinal fusions techniques. We analyzed the influence of age, Body Mass Index (BMI), smoking, diabetes, and previous surgery on the rate of ADTs in MISS.

Results: Twenty-two patients (11.764%) suffered from an ADT. We recommended bed rest for two and a half to 5 days, depending on the type of repair required and the amount of cerebrospinal fluid (CSF) leakage. We could not find any statistically significant correlation between ADTs and age (p = 0.34,), BMI (p = 0.92), smoking (p = 0.46), and diabetes (p = 0.71). ADTs were significantly more frequent in cases of previous surgery (p < 0.001). None of the patients developed a transcutaneous CSF leak or post-operative infection.

Conclusions: The frequency of ADTs in MISS appears comparable to that encountered when using open surgical techniques. Additionally, MAST produces less dead space along the corridor to the spine. Such reduced dead space may not be enough for pseudomeningocele to occur, cerebrospinal fluid to accumulate, and fistula to form. MAST, therefore, provides a certain amount of protection.

Risk Factors for Accidental Dural Tears in Spinal Surgery

BACKGROUND

Accidental dural tears (DTs) are familiar complications of spinal surgery. Their reported incidence varies widely, and several risk factors have been proposed in the literature. The aim of this study was to conduct a systematic review and meta-analysis to determine the rate of DTs and assess their associated risk factors.

METHODS

A systematic literature search was conducted using specific MeSH and Text terms. Only articles with prospective data reporting the incidence and risk factors were selected and reviewed based on specific inclusion and exclusion criteria.

RESULTS

Twenty-three studies were included. The reported incidence rate ranged from 0.4% to 15.8%, giving an overall pooled incidence rate of 5.8% (95% confidence interval [CI] 4.4-7.3). The incidence rate varied in relation to the part of the spine and the type of surgery. Three factors were associated with a high rate of DTs: age (overall mean difference of 3.04, 95% CI 2.49-3.60), revision surgery (overall odds ratio of 2.28, 95% CI 1.84-2.83), and lumbar stenosis (overall odds ratio of 2.03, 95% CI 1.50-2.75). Diabetes was weakly associated with DTs, with an odds ratio of 1.40 (95% CI 1.01-1.93). The overall effects of sex and obesity were not statistically significant.

CONCLUSION

Advancing age, revision surgery, and lumbar stenosis were significantly associated with increased risk of DTs. These factors should be taken into consideration during the consenting process for spinal surgery.

CLINICAL RELEVANCE

Risk of dural tear during spine surgery.

Clinical Outcome of Spine Surgery Complicated by Accidental Dural Tears: Meta-Analysis of the Literature

STUDY DESIGN

Systemic review and meta-analysis.

OBJECTIVES

Several studies have reported the impact of accidental dural tears (DT) on the outcome of spinal surgery, some with conflicting results. Therefore, the aim of this study was to carry out a systemic review and meta-analysis of the literature to establish the overall clinical outcome of spinal surgery following accidental DT.

METHOD

A systemic literature search was carried out. Postoperative improvement in Oswestry Disability Index (ODI), Short-Form 36 survey (SF36), leg pain visual analogue scale (VAS), and back pain VAS were compared between patients with and without DT at different time intervals.

RESULTS

Eleven studies were included in this meta-analysis. There was a slightly better improvement in ODI and leg VAS score (standardized mean difference of -0.06, 95% confidence interval [CI] -0.12 to -0.01, and -0.06, 95% CI -0.09 to -0.02, respectively) in patients without DT at 12 months postsurgery, but this effect was not demonstrated at any other time intervals up to 4 years. There were no differences in the overall SF36 (function) score at any time interval or back pain VAS at 12 months.

CONCLUSION

Based on this study, accidental DT did not have an overall significant adverse impact on the short-term clinical outcome of spinal surgery. More studies are needed to address the long-term impact and other outcome measures including other immediate complications of DT.

Inside-Out Approach of Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: A Detailed Technical Description, Rationale and Outcomes

Although lumbar stenosis was recognized as a contraindication for endoscopic spine surgery in the past, the advancement in endoscopic system design and development of approach techniques and strategies now enabled the endoscopic spine surgeons to manage all types of lumbar stenosis safely and more effectively. A full-endoscopic lumbar technique for surgical management of spinal canal stenosis is now used today in many advanced spine centers around the world as one of their standard procedures which can be done under general, regional, local anesthesia with sedation. In this technical report, we described in detail the inside-out approach of performing lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD) and retrospectively reviewed hospital records of 127 patients who underwent the approach from December 2018 to March 2019 to address 1 level lumbar spinal stenosis and determined its outcome after 12-month follow-up period. Perioperative outcomes, operation time, length of hospital stay, and surgical complications were recorded and analyzed. The cross-sectional area of the thecal sac at the operated level was measured. The visual analogue scale (VAS) was assessed preoperatively, 1 month, and 12 months as well as the Oswestry Disability Index (ODI). The data were statistically analyzed (using SPSS ver. 17.0). The inside-out approach LE-ULBD was shown to effect statistically significant improvement in the VAS of leg and back pain as well as the ODI. It is a familiar, safe, and effective way of performing spinal stenosis decompression with good reproducible outcomes.

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.

Decompressive Surgery for Lumbar Spinal Stenosis: WFNS Spine Committee Recommendations

Objective

Lumbar spine stenosis is a common disease with a prevalence progressively increasing due to the aging of the population. Despite many papers having been published over the last decades, there still remain many doubts regarding its natural history and appropriate treatment. To overcome these problems and reach some globally accepted recommendations, the World Federation of Neurosurgical Society Spine Committee organized a consensus conference on this topic. This paper describes recommendations about the efficacy of surgical decompression, the difference between surgical techniques, and complications of surgery.

Methods

World Federation of Neurosurgical Society Spine Committee aimed to standardize clinical practice worldwide as much as possible and held a 2-round consensus conference on lumbar spinal stenosis. A team of expert spine surgeons reviewed literature regarding surgical treatment from over the last 10 years, and then drafted and voted on some statements based on the presented literature.

Results

Ten statements were voted. The committee agreed on the effectiveness of surgical decompression in patients with moderate-to-severe symptoms or with neurologic deficits. There was no consensus on the best surgical technique and, in particular, about the equivalence of microscopic techniques and an open approach. Regarding complications, we agreed that the most frequent complications are incidental durotomy and general complications in the elderly.

Conclusions

Surgical decompression represents the treatment of choice for symptomatic lumbar spinal stenosis with a low complication rate. However, which surgical technique is the best is still under debate. Further studies with standardized outcome measures are needed to understand the real complication rate and frequency of different unwanted events.

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.

Incidental durotomy in degenerative lumbar spine surgery - a register study of 64,431 operations

BACKGROUND

Incidental durotomy (ID) is one of the most common intraoperative complications seen in spine surgery. Conflicting evidence has been presented regarding whether or not outcomes are affected by the presence of an ID.

PURPOSE

To evaluate whether outcomes following degenerative spine surgery are affected by ID and the incidence of ID with different diagnoses and different surgical procedures.

MATERIALS

By using SweSpine, the national Swedish Spine Surgery Register, preoperative, surgical and postoperative 1-year follow-up data were obtained for 64,431 surgeries. All patients were surgically treated due to lumbar spinal stenosis (LSS) without or with concomitant degenerative spondylolisthesis (DS) or lumbar disc herniation (LDH) between 2000 and 2015. Gender, age, smoking habits, walking distance, consumption of analgesics, back and leg pain (Visual Analogue Scale [VAS]), quality of life (EuroQol [EQ5D] and Short Form 36 [SF-36]), and disability (Oswestry Disability Index [ODI]) were recorded.

RESULTS

Overall, incidence of ID during the study period was 5.0%. For the LDH, LSS, and DS subgroups, it was 2.8%, 6.5%, and 6.5%, respectively. Laminectomy was associated with a higher incidence of ID than discectomy (p<.001). ID was more common in all three subgroups if the patient had previously been subjected to spine surgery and with increasing age of the patients (p<.001). LDH patients with an ID reported a higher degree of residual leg pain, inferior mental quality of life (SF-36 MCS), and higher disability (ODI) than LDH patients without ID (all p<.001) 1-year after surgery. LSS patients with an ID reported inferior SF-36 MCS (p<.001) and DS patients with an ID had inferior SF-36 MCS and higher ODI compared to patients with the same diagnosis but without an ID (p<.001). However, these numerical differences are well below references for MCID, for all three subgroups. ID was associated with a higher frequency of patients being dissatisfied with the surgical outcome at 1-year follow-up. In patients who did not improve in back and leg pain following surgery (delta-value), ID was less common than in patients reporting improved back and leg pain from before as compared to following surgery.

CONCLUSIONS

The overall occurrence of ID in the present study was 5%, with higher figures in LSS and DS and lower figures in LDH. Higher age of the patient and previous surgery were associated with higher frequencies of ID. The outcome at 1 year following surgery was not affected to a clinically relevant extent when an ID was obtained. However, ID was associated with a higher degree of patient dissatisfaction and a longer hospital length of stay.

Is MIS-TLIF superior to open TLIF in obese patients?: A systematic review and meta-analysis

PURPOSE

Obesity is a global health problem. It increases the risk of surgical complications and re-operations. While both MIS-TLIF and O-TLIF are reported to have comparably good long-term outcomes for non-obese patients, no consensus has been reached for obese patients.

METHODS

A comprehensive search of the published literature was performed: PubMed, Scopus, Web of Science and Cochrane Central Register of Controlled Trials database in accordance to the PRISMA 2009 checklist. Data were collected with attention to baseline demographics, intra-operative blood loss, duration of surgery, surgical complications, hospitalization stay, VAS and Oswestry disability index (ODI) pre- and postoperatively.

RESULTS

A total of 863 abstracts were identified from the databases, of which 4 articles were included in the meta-analysis. A total of 430 patients were identified, of which 217(50.5%) underwent the O-TLIF, while 213(49.5%) underwent MIS-TLIF. One hundred and ninety-four (45.1%) patients were males, while 236(54.9%) were females. The average age was 54.8 ± 12.0 years. The pooled BMI was 33.4 ± 4.7 for the open-TLIF group, and 32.7 ± 3.9 for MIS-TLIF group (p = 0.22). When comparing O-TLIF to MIS-TLIF: Patients who underwent O-TLIF had 383 mls more blood loss (95% CI: 329.5-437.4, p < 0.00001), 1.2-day longer hospitalization stay (95% CI: 0.80-1.62, p < 0.00001) and 3.8 times higher risk of dural tear (95% CI: 1.61-9.87, p = 0.003) when compared to MIS-TLIF patients. A trend toward higher postoperative wound infection rates (O-TLIF: 4.5%, MIS-TLIF: 2.4%) and an inferior improvement in ODI score (O-TLIF: 39.3, MIS-TLIF: 44.1) was found in O-TLIF patients when compared to MIS-TLIF patients. However, these were not statistically significant.

CONCLUSION

MIS-TLIF is safe and may be a better option for lumbar fusion in obese patients. These slides can be retrieved under Electronic Supplementary Material.

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.

Spinal versus general anesthesia for lumbar spine surgery in high risk patients: Perioperative hemodynamic stability, complications and costs

OBJECTIVE

More stable perioperative hemodynamic conditions, lower costs and a lower perioperative complication rate were reported in young healthy patients undergoing lumbar spine surgery in spinal anesthesia (SA) compared to general anesthesia (GA). However, the benefits of SA in high risk patients (ASA≥II suffering from cardiovascular and/or pulmonary pathologies) undergoing this surgery are unclear. Our objective was to analyze whether SA leads to an improved perioperative hemodynamic stability and to a more cost-effective management compared to GA in high risk patients undergoing this surgery.

METHODS

In a retrospective analysis 146 ASA II-III patients who underwent lumbar spine surgery in SA were compared with 292 ASA I-III patients who were operated in GA between 2000 and 2014. Hemodynamic effects, hospitalization times, complications, and costs according to the Swiss billing system were assessed. The data extraction was conducted according to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) initiative for cohort studies.

RESULTS

The patients in the SA group were older (75years (±9.6) vs 69 (±11.5), p<0.001), had a lower BMI (25.8kg/m2 (±4.8) vs 27.2 (±4.7), p=0.003) and showed a higher ASA score (3 vs 2, p<0.001). However, SA was associated with significantly better perioperative hemodynamic stability with less need for intraoperative vasopressors (15% vs 57%, p<0.001), volume supplementation (1113ml ±458 vs 1589±644, p<0.001) and transfusions (0% vs 4%, p<0.001). Additionally, the number of hypotension episodes was lower in the SA group (15% vs 47%, p<0.001). Furthermore, the SA group showed a significantly shorter duration of surgery (70min (±1.2) vs 91 (±41), p<0.001), lower postoperative nausea and vomiting (PONV) (4% vs 28%, p<0.001) and pain in the post anesthesia care unit (PACU) (visual analogue scale (VAS) 2.3 (±1.1) vs 0.8 (±0.8), p<0.001), whereas pain after 24h did not differ (VAS 0.9 (±1) vs 0.8 (±1.1), p=ns). The postoperative complication (7% vs 5%, p=0.286) and revision rates (4% vs 5%, p=0.626) were similar in both groups. Total costs (United States Dollars (USD) 6377 (±2332) vs 7018 (±4056), p=0.003) and PACU time were significantly lower in the SA group (35min (±12) vs 109 (±173), p<0.001).

CONCLUSIONS

Lumbar spine surgery in cardiovascular high risk patients with SA is safe, allows good perioperative hemodynamic stability and might lead to lower health care costs. Further prospective studies are needed to confirm these findings.

[Not Available]

Zusammenfassung. Zur exakten Erfassung von Schmerzen, funktionellen Einschränkungen und gesundheitsbezogener Lebensqualität bei Patienten mit degenerativen Wirbelsäulenerkrankungen existiert eine Reihe validierter Messinstrumente. Neben der Beurteilung durch den Therapeuten sowie «subjektiven» patientenorientierten Messmethoden (PROMs) wurde in den vergangenen Jahren der «Timed Up and Go»(TUG)-Test systematisch untersucht und als krankheitsspezifisches Messinstrument validiert. Heute kann eine objektive funktionelle Einschränkung (OFI = Objective Functional Impairment) in wenigen Sekunden und kostenfrei mithilfe einer Smartphone-Applikation bestimmt werden. Die Bestimmung von Z- oder T-Werten, die TUG-Testergebnisse in Relation zur Populationsnorm setzen, ermöglichen eine alters- und geschlechtsadjustierte Ergebnisinterpretation. Diese Übersichtsarbeit fasst die aktuellen Erkenntnisse zu objektiven Messmethoden bei degenerativen Wirbelsäulenpathologien inklusive deren Vor- und Nachteile zusammen und vergleicht sie mit den bisherigen Beurteilungsmethoden für funktionelle Outcomes.

Incidental durotomy in decompression for lumbar spinal stenosis: incidence, risk factors and effect on outcomes in the Spine Tango registry

PURPOSE

The three aims of this Spine Tango registry study of patients undergoing decompression for spinal stenosis were to: report the rate of dural tear (DT) stratified by treatment centre; find factors associated with an increased likelihood of incurring a DT; and compare treatment outcomes in relation to DT (none vs. repaired vs. unrepaired DT).

METHODS

Multivariate logistic regression was used to assess the association between DT and patient and treatment characteristics. Patient-rated and surgical outcomes were compared in patients with no DT, repaired DT, and unrepaired DT, while adjusting for case-mix.

RESULTS

DT occurred in 328/3254 (10.1%) of included patients. The rate for all 29 contributing hospitals was within 95% confidence intervals of the average. The likelihood of DT increased by 2% per year of age, 1.78 times with previous spine surgery, 1.67 for a minimally/less invasive surgery, 1.58 times with laminectomy, and 1.40, and 2.12 times for BMI 31-35, and >35 in comparison with BMI 26-30, respectively. The majority of DTs (272/328; 82.9%) were repaired. Repairing the DT was associated with a longer duration of surgery (p < 0.001). More patients with repaired than with unrepaired DTs were satisfied with treatment, but the difference was not statistically significant. There was no association between DT and patient-reported outcomes.

CONCLUSION

The unadjusted rate of incidental DT during decompression for LSS was homogeneous across the participating centres and was associated with age, BMI, previous surgery at the same spinal level, minimally/less invasive surgery, and laminectomy. Non-repair of DTs had no negative association with treatment outcome; however, the unrepaired DTs may have been those that were smaller in size.

Lumbar microdiscectomy as a day-case procedure: Scope for improvement?

BACKGROUND AND PURPOSE

There are no significant differences in outcomes between patients receiving inpatient and day-case lumbar microdiscectomy, but the latter is still underused in the NHS. Here we aimed to identify factors contributing to successful same-day discharge in day-case patients.

METHODS

This was a retrospective observational study of patients undergoing elective lumbar microdiscectomy between August 2012 and December 2014. Age, gender, day of surgery, distance to hospital, ASA grade, regular opiate use, smoking status, order on the operating list, and side and level of surgery were examined by logistic regression to assess their influence on same-day discharge.

RESULTS

28/95 (29.5%) patients were discharged on the day of surgery. Age (p = 0.041), ASA grade (p = 0.016), distance to hospital (p = 0.011), and position on the list (p = 0.004) were associated with day-case discharge by univariate analysis. ASA grade (p = 0.032; OR 0.176), distance to hospital (p = 0.003; OR 0.965), and position on the operating list (morning case; p = 0.011; OR 8.901) remained significant in multivariate analysis. Thirteen (13.7%) patients were identified who could have been managed as day cases had they been listed for morning operations.

CONCLUSIONS

Day-case lumbar microdiscectomy is viable when patients are carefully selected. Younger, fit patients living close to the hospital and operated on in the morning are more likely to be discharged on the same day. Knowledge of these factors while planning elective lists can help optimise bed space and improve spinal services.

A novel use of the Spine Tango registry to evaluate selection bias in patient recruitment into clinical studies: an analysis of patients participating in the Lumbar Spinal Stenosis Outcome Study (LSOS)

PURPOSE

Patients enrolled in clinical studies typically represent a sub-set of all who are eligible, and selection bias may compromise the generalizability of the findings. Using Registry data, we evaluated whether surgical patients recruited by one of the referring centres into the Lumbar Spinal Stenosis Outcome Study (LSOS; a large-scale, multicentre prospective observational study to determine the probability of clinical benefit after surgery) differed in any significant way from those who were eligible but not enrolled.

METHODS

Data were extracted for all patients with lumbar spinal stenosis registered in our in-house database (interfaced to Eurospine's Spine Tango Registry) from 2011 to 2013. Patient records and imaging were evaluated in relation to the admission criteria for LSOS to identify those who would have been eligible for participation but were not enrolled (non-LSOS). The Tango surgery data and Core Outcome Measures Index (COMI) data at baseline and 3 and 12 months after surgery were analysed to evaluate the factors associated with LSOS enrolment or not.

RESULTS

514 potentially eligible patients were identified, of which 94 (18%) were enrolled into LSOS (range 2-48% for the 6 spine surgeons involved in recruiting patients) and 420 (82%) were not; the vast majority of the latter were due to non-referral to the study by the surgeon, with only 5% actually refusing participation. There was no significant difference in gender, age, BMI, smoking status, or ASA score between the two groups (p ≥ 0.18). Baseline COMI was significantly (p = 0.002) worse in the non-LSOS group (7.4 ± 1.9) than the LSOS group (6.7 ± 1.9). There were no significant group differences in any Tango surgery parameters (additional spine patholothegies, operation time, blood loss, complications, etc.) although significantly more patients in the non-LSOS group had a fusion procedure (38 vs 18% in LSOS; p = 0.0004). Postoperatively, neither the COMI nor its subdomain scores differed significantly between the groups (p > 0.05). Multiple logistic regression revealed that worse baseline COMI (p = 0.021), surgeon (p = 0.003), and having fusion (p = 0.014) predicted non-enrolment in LSOS.

CONCLUSION

A high proportion of eligible patients were not enrolled in the study. Non-enrolment was explained in part by the specific surgeon, worse baseline COMI status, and having a fusion. The findings may reflect a tendency of the referring surgeon not to overburden more disabled patients and those undergoing more extensive surgery with the commitments of a study. Beyond these factors, non-enrolment appeared to be somewhat arbitrary, and was likely related to surgeon forgetfulness, time constraints, and administrative errors. Researchers should be aware of potential selection bias in their clinical studies, measure it (where possible) and discuss its implications for the interpretation of the study's findings.