Risk factors for incidental durotomy during lumbar surgery: a retrospective study by multivariate analysis

Incidental Durotomy Repair in Lumbar Spine Surgery: Institutional Experience and Review of Literature

STUDY DESIGN

: Retrospective Chart Review.

OBJECTIVES

Incidental durotomies (IDs) are common spine surgery complications. In this study, we present a review on the most commonly utilized management strategies, report our institutional experience with case examples, and describe a stepwise management algorithm.

METHODS

A retrospective review was performed of the electronic medical records of all patients who underwent a thoracolumbar or lumbar spine surgery between March 2017 and September 2019. Additionally, a literature review of the current management approaches to treat IDs and persistent postoperative CSF leaks following lumbar spine surgeries was performed.

RESULTS

We looked at 1133 patients that underwent posterior thoracolumbar spine surgery. There was intraoperative evidence of ID in 116 cases. Based on our cohort and the current literature, we developed a progressive treatment algorithm for IDs that begins with a primary repair, which can be bolstered by dural sealants or a muscle patch. If this fails, the primary repair can be followed by a paraspinal muscle flap, as well as a lumbar drain. If the patient cannot be weaned from temporary CSF diversion, the final step in controlling postoperative leak is longterm CSF diversion via a lumboperitoneal shunt. In our experience, these shunts can be weaned once the patient has no further clinical or radiographic signs of CSF leak.

CONCLUSIONS

There is no standardized management approach of IDs and CSF leaks in the literature. This article intends to provide a progressive treatment algorithm and contribute to the development process of a treatment consensus.

Minimally invasive tubular microdiscectomy for recurrent lumbar disc herniation: step-by-step technical description with safe scar dissection

INTRODUCTION

Recurrent lumbar disc herniation (RLDH) is one of the most common reasons for re-operation after primary lumbar disc herniation with an incidence ranging from 5 to 23%. Numerous RLDH studies have been conducted; however, no available studies have provided a specific description of the use of the tubular retractor discectomy technique for RLDH emphasizing safe scar dissection. The objective of this study is to describe a detailed step-by-step technique for RLDH.

MATERIAL AND METHODS

A surgical technique reporting on our experience from the year 2013-2021 in 9 patients with RLDH at the same level and same side was included in the study. Clinical outcomes were assessed using the visual analog score (VAS) for leg pain before and three months after surgery.

RESULTS

A significant improvement was observed between the preoperative and postoperative VASs [mean (SD): 9.2 (1) vs. 1.5 (1)] for all patients. We did not report any incidental durotomy, neurological deficits or mortality in this study. One patient had superficial wound infection. The study is limited by small population, short follow-up and not reporting stability or spondylolisthesis.

CONCLUSION

A modified tubular discectomy technique with safe scar dissection is effective for RLDH treatment. Technically, the only scar needed to be dissected is the scar lateral to the exposed normal dura and the scar extended caudally till the level of the superior end plate of the targeted disc space where the scar can be entered ventrally and the disc fragment retrieved. Adherence to the step-by-step procedure described in our study will help surgeons operate with more confidence and minimize complications of recurrent lumbar disc herniation.

Clinical management of dural defects: A review

Dural defects are common in spinal and cranial neurosurgery. A series of complications, such as cerebrospinal fluid leakage, occur after rupture of the dura. Therefore, treatment strategies are necessary to reduce or avoid complications. This review comprehensively summarizes the common causes, risk factors, clinical complications, and repair methods of dural defects. The latest research progress on dural repair methods and materials is summarized, including direct sutures, grafts, biomaterials, non-biomaterial materials, and composites formed by different materials. The characteristics and efficacy of these dural substitutes are reviewed, and these materials and methods are systematically evaluated. Finally, the best methods for dural repair and the challenges and future prospects of new dural repair materials are discussed.

Complications after early versus late mobilization after an incidental durotomy: a systematic review and meta-analysis

BACKGROUND

An incidental durotomy (IDT) is a frequent complication of spinal surgery. The conventional management involving a period of flat bed rest is highly debatable. Indeed, there are scanty data and no consensus regarding the need or ideal duration of post-operative bed rest following IDT.

OBJECTIVE

To systematically evaluate the literature regarding the outcomes of mobilization within 24 h and after 24 h following IDT in open lumbar or thoracic surgery with respect to the length of hospital stay, minor and major complications.

METHODS

A systematic review of the literature using PubMed, Embase and Cochrane and dating up until September 2022 was undertaken following Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Quality of evidence was assessed using a modified version of Sackett's Criteria of Evidence Support.

RESULTS

Out of 532 articles, 6 studies met the inclusion criteria (1 Level-I, 4 level-III and 1 Level-IV evidence) and were analyzed. Overall, 398 patients of mean age 59.9 years were mobilized within 24 h. The average length of stay (LOS) for this group was 5.7 days. Thirty-four patients (8.5%) required reoperation while the rate of minor complications was 25.4%. Additionally, 265 patients of mean age 63 years with IDT were mobilized after 24 h. The average LOS was 7.8 days. Twenty patients (7.54%) required reoperation while the rate of minor complications was 55%. Meta-analysis comparing early to late mobilization, showed a significant reduction in the risk of minor complications and shorter overall LOS due to early mobilization, but no significant difference in major complications and reoperation rates.

CONCLUSIONS

Although early mobilization after repaired incidental dural tears in open lumbar and thoracic spinal surgery has a similar major complication/ reoperation rates compared to late mobilization, it significantly decreases the risk of minor complications and length of hospitalization.

Are Octogenarians at Higher Risk of Complications After Elective Lumbar Spinal Fusion Surgery? Analysis of a Cohort of 7880 Patients From the Kaiser Permanente Spine Registry

STUDY DESIGN

A retrospective cohort study with chart review.

OBJECTIVE

To determine if there is a difference in risk of adverse outcomes following elective posterior instrumented lumbar spinal fusions for patients aged 80 years and above compared with patients aged 50 to 79 years.

SUMMARY OF BACKGROUND DATA

Patients aged 80 years and above are undergoing elective lumbar spinal fusion surgery in increasing numbers. There are conflicting data on the risks of intraoperative and postoperative complications in these patients.

MATERIALS AND METHODS

Patients aged 80 years and above were compared with 50 to 79 years (reference group) using time-dependent multivariable Cox proportional hazards regression with a competing risk of death for longitudinal outcomes and multivariable logistic regression for binary outcomes. Outcome measures used were: (1) intraoperative complications (durotomy), (2) postoperative complications: 30-day outcomes (pneumonia); 90-day outcomes (deep vein thrombosis, pulmonary embolism, emergency room visits, readmission, reoperations, and mortality); and two-year outcomes (reoperations and mortality).

RESULTS

The cohort consisted of 7880 patients who underwent primary elective posterior instrumented lumbar spinal fusion (L1-S1) for degenerative disk disease or spondylolisthesis. This was subdivided into 596 patients were aged 80 years and above and 7284 patients aged 50 to 79. After adjustment, patients aged 80 years and above had a higher likelihood of durotomy [odds ratio (OR)=1.43, 95% confidence interval (CI)=1.02-2.02] and 30-day pneumonia (OR=1.81, 95% CI=1.01-3.23). However, there was a lower risk of reoperation within two years of the index procedure (hazard ratio=0.69, 95% CI=0.48-0.99). No differences were observed for mortality, readmissions, emergency room visits, pulmonary embolism, or deep vein thrombosis.

CONCLUSIONS

In a cohort of 7880 elective posterior instrumented lumbar fusion patients for degenerative disk disease or spondylolisthesis, we did not observe any significant risks of adverse events between patients aged 80 years and above and those aged 50 to 79 except for higher durotomies and 30-day pneumonia in the former. We believe octogenarians can safely undergo lumbar fusions, but proper preoperative screening is necessary to reduce the risks of 30-day pneumonia.

Incidence and risk factors for incidental durotomy in spine surgery for lumbar stenosis and herniated disc

PURPOSE

Incidental durotomy (ID) is one of the most common complications in degenerative surgery. Due to the negative consequences of ID, knowledge about incidence and risk factors is warranted.

METHODS

A total of 1,139 surgical procedures for lumbar spinal stenosis (LS) and lumbar herniated disc (LDH) were included from the spine surgery database: DaneSpine. Uni- and multivariate analyses were performed for the assessment of possible risk factors.

RESULTS

ID occurred in 10.4% of the surgical procedures. A multivariate regression analysis revealed an increased relative risk of ID by 2% per year of age, 58% by revision surgery, and 55% by decompression on multiple levels.

CONCLUSION

In our single-centre cohort study, one in ten patients experiences an ID. Increasing age, revision surgery and decompression of multiple levels are risk factors of ID in degenerative surgery of the lumbar spine.

Comparison of Transthecal Approach With Traditional Conservative Approach for Primary Closure After Incidental Durotomy in Anterior Lumbar Tear

BACKGROUND

Incidental durotomies (IDs) are frequent complications of spinal surgeries which are mostly posterior or lateral. Anterior IDs are rare; however, they may lead to severe complications. We compared the transthecal approach with the conservative approach for primary closure after durotomy in anterior lumbar dural tear to assess the efficacy of these approaches to decrease postsurgical complications and clinical outcomes.

METHODS

A total of 21 patients undergoing L2-S1 laminectomy with anterior ID were randomly divided into a transthecal group (n = 9) and a conservative group (n = 12) based on the surgical dural closure technique. Postoperative pseudomeningocele, wound infection, rootlet herniation, pneumocephalus, cerebrospinal fluid (CSF) leakage, headache, meningitis, in addition to surgery duration and length of hospitalization were examined and compared in both groups.

RESULTS

The frequency of pseudomeningocele and CSF leakage in patients undergoing the transthecal approach was significantly lower than those undergoing the conservative approach (P = .045 and .008, respectively). Furthermore, although the differences in the frequency of meningitis, pneumocephalus, headache, and wound infection were not statistically significant between the 2 groups, the effect sizes of the comparison were obtained as 49.4, 19.8, 7.1, and 2.6, respectively. This indicated that the differences were clinically significant between the 2 groups.

CONCLUSIONS

We found that the transthecal approach was significantly more successful in managing CSF leakage as well as its complications and clinical outcomes. However, further clinical trials with bigger sample sizes are needed to substantiate this claim.

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.

Does the Number of Levels Fused Affect Spinopelvic Parameters and Clinical Outcomes Following Posterolateral Lumbar Fusion for Low-Grade Spondylolisthesis?

STUDY DESIGN

Retrospective cohort.

OBJECTIVES

To determine how the number of fused intervertebral levels affects radiographic parameters and clinical outcomes in patients undergoing open posterolateral lumbar fusion (PLF) for low-grade degenerative spondylolisthesis.

METHODS

This was a retrospective cohort study on patients who underwent open PLF for low-grade spondylolisthesis at a single institution from 2011 to 2018. Patients were divided into groups based on number of levels fused during their procedure (1, 2, or 3 or more). Preoperative and postoperative spinopelvic radiographic parameters, patient-reported outcomes (Visual Analog Scale [VAS]-back, VAS-leg, Oswestry Disability Index [ODI]), and postoperative complications were compared.

RESULTS

Of the 316 patients eligible (203 one-level, 95 two-level, 18 three or more levels), change in initial postoperative to final pelvic incidence-lumbar lordosis was greatest in 2-level fusions (P = .039), while 3 or more level fusions had worse final pelvic tilt measures (P = .021). In addition, multilevel fusions had worse final VAS-back scores (2-level: P = .015; 3 or more levels: P = .011), higher rates of dural tears (2-level: P = .001), reoperation (2-level: P = .039), and discharge to facility (3 or more levels: P = .047) when compared with 1-level fusions.

CONCLUSIONS

Patients in multilevel fusions experienced less improvement in back pain, had more complications, and were more commonly discharged to a facility compared with single-level PLF patients. These findings are important for operative planning, for setting appropriate preoperative expectations, and for risk stratification in patients undergoing posterior lumbar fusion for low-grade spondylolisthesis.

Management of Incidental Durotomy: Results from a Nationwide Survey Conducted by the French Society of Spine Surgery

OBJECTIVE

To obtain real-life data on the most common practices used for management of incidental durotomy (ID) in France.

METHODS

Data were collected from spinal surgeons using a practice-based online questionnaire. The survey comprised 31 questions on the current management of ID in France. The primary outcome was the identification of areas of consensus and uncertainty on ID follow-up.

RESULTS

A total of 217 surgeons (mainly orthopaedic surgeons and neurosurgeons) completed the questionnaire and were included in the analysis. There was a consensus on ID repair with 94.5% of the surgeons considering that an ID should always be repaired, if repairable, and 97.2% performing a repair if an ID occurred. The most popular techniques were simple suture or locked continuous suture (48.3% vs. 57.8% of surgeons). Nonrepairable IDs were more likely to be treated with surgical sealants than with an endogenous graft (84.9% vs. 75.5%). Almost two thirds of surgeons (71.6%) who adapted their standard postoperative protocol after an ID recommended bed rest in the supine position. Among these, 48.8% recommended 24 hours of bed rest, while 53.5% recommended 48 hours of bed rest. The surgeons considered that the main risk factors for ID were revision surgery (98.6%), patient's age (46.8%), surgeon's exhaustion (46.3%), and patient's weight (21.3%).

CONCLUSIONS

This nationwide survey reflects the lack of a standardized management protocol for ID. Practices among surgeons remain very heterogeneous. Further consensus studies are required to develop a standard management protocol for ID.

Incidental Durotomy Following Transforaminal Lumbar Interbody Fusion Performed with the Modified Wiltse Approach

PURPOSE

 Incidental durotomy is an intraoperative complication that occurs in 3 to 27% of lumbar spine surgeries. It has been reported more commonly following revision spinal procedures.

STUDY OBJECTIVES

 To investigate the frequency of incidental durotomy while performing transforaminal lumbar interbody fusion (TLIF) using the modified Wiltse approach. A secondary goal was to compare the incidence of durotomy in patients undergoing primary spine surgery with those undergoing revision surgery.

METHODS

 A group of consecutive patients who had undergone (TLIF) in the last 10 years ending in 2015 were enrolled in the study. All patients underwent TLIF via the modified Wiltse approach that included a central midline skin incision, followed by a paravertebral blunt dissection of the paraspinal muscles to reach the transverse processes. The deep paravertebral dissection was done conservatively, one side at a time. Demographic and clinical data were collected when relevant to the comparison.

RESULTS

 The study cohort encompassed 257 patients: 200 primary cases and 57 revisions. The frequency of incidental durotomy was equal in both groups: 3.5% each (7/200 and 2/57). All durotomies were repaired primarily. No other immediate or late complications were observed during follow-up.

CONCLUSION

 The present study displays a limited incidence of durotomy in the primary interventions and to a lesser degree in the revisions, all of which had used a TLIF performed with the modified Wiltse approach. This procedure probably circumvented the need for further revisions.

Recent Preoperative Lumbar Epidural Steroid Injection Is an Independent Risk Factor for Incidental Durotomy During Lumbar Discectomy

STUDY DESIGN

Retrospective review.

OBJECTIVE

To investigate the association between lumbar epidural steroid injection (LESI) and incidental durotomy (ID) in patients with a diagnosis of disc herniation undergoing a primary discectomy.

METHODS

A Medicare patient database was queried for patients between the ages of 65 and 85 years who underwent a primary lumbar discectomy for a diagnosis of lumbar disc herniation or degeneration from 2008 to 2014. Our main cohort of 64 849 patients was then divided into 2 groups: patients who experienced a dural tear (N = 2369) and our matched (age, gender, and history of diabetes) control cohort of patients who did not (N = 62 480). All patients who had a history of LESI were further identified and stratified into 4 subgroups by duration between LESI and discectomy (<3 months, 3-6 months, 6 months to 1 year, and overall), and a comparison of the relative incidence of ID was made among these subgroups. A multivariate logistic regression analysis was employed to determine the relationship between LESI and ID.

RESULTS

Overall incidence of ID was 3.7%. There was a significant difference in incidence of LESI (27.1% vs 35.0%, P < .001) between our control and ID groups. An adjusted odds ratio (OR) showed that prior LESI within 3 to 6 months (OR 1.47, 95% CI 1.20-1.81, P < .001) and within less than 3 months (OR 1.46, 95% CI 1.24-1.72, P < .001) of surgery were significantly associated with ID.

CONCLUSION

LESI increases the risk of ID in patients who undergo a subsequent lumbar discectomy within 6 months of injection.

Safe Discharge of Patients From an Ambulatory Care Center After Incidental Durotomy During Minimally Invasive Spine Surgery

Background

Incidental durotomy is a well-known complication of spinal surgery that may occur occasionally. Increasingly, minimally invasive techniques are being used for spinal decompressions in an ambulatory surgical center (ASC) setting. The management of this complication in an ASC setting has not been reported.

Methods

A total of 832 consecutive minimally invasive decompressive spinal surgeries were performed by a single surgeon in an ASC during the course of 1 year. Incidental durotomies with cerebrospinal fluid leakage were repaired and patients were discharged to home. Patients with a watertight suture dural repair did not receive any modifications to the usual discharge activities allowed. All other patients were treated with bed rest overnight and head of bed restrictions. A protocol for close patient follow-up after discharge was followed. The complications were collected prospectively and analyzed retrospectively.

Results

There were 30 incidental durotomies (3.6%), with all occurring in the lumbar spine. Suture repair was accomplished in 28 patients (93%). Patch repair was performed in 2 patients (7%). All patients were discharged to home from the ASC. There were 2 short-term complications noted after discharge. The patient safety protocols in place identified the complications and allowed timely interventions.

Conclusions

Incidental durotomy occurring during minimally invasive spinal decompressive surgery is an occasional event. Suture repair of the laceration is feasible in most instances. Lumbar spine patients may be safely discharged to home from the ASC. Patients can be stratified into those with, or without, a watertight suture dural closure. Those with such a closure, who are without symptoms of intracranial hypotension, do not require modification of their activities. A short period of bedrest with head of bed modification successfully treated the remainder. Hospitalization or routine prolonged bed rest is not necessary. Protocols must be put in place to identify and timely manage potentially serious sequelae.

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.

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

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk factors for dural tears: a study of elective spine surgery. Neurol Res 2016;39:97-106. [PMID: 27908218 DOI: 10.1080/01616412.2016.1261236]

OBJECTIVE

This study moves beyond previous cohort studies and benchmark data by studying a population of elective spine surgery from a multicenter registry in an effort to validate, disprove, and/or identify novel risk factors for dural tears.

METHODS

A retrospective cohort analysis queried a multicenter registry for patients with degenerative spinal diagnoses undergoing elective spinal surgery from 2010-2014. Multivariable logistic regression analysis interrogated for independent risk factors of dural tears.

RESULTS

Of 104,930 patients, a dural tear requiring repair occurred in 0.6% of cases. On adjusted analysis, the following factors were independently associated with increased likelihood of a dural tear: ankylosing spondylitis vs. intervertebral disc disorders, greater than two levels, combined surgical approach and posterior approach vs. anterior approach, decompression only vs. fusion and decompression, age groups 85+, 75-84 and 65-74 vs. <65, obesity (BMI ≥30), corticosteroid use and preoperative platelet count <150,000.

CONCLUSIONS

This multicenter study identifies novel risk factors for dural tears in the elective spine surgery population, including corticosteroids, thrombocytopenia, and ankylosing spondylitis. The results of this analysis provide further information for surgeons to use both in operative planning and in preoperative counseling when discussing the risk of dural tears.

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.