Unintended dural tears during unilateral biportal endoscopic lumbar surgery: incidence and risk factors

BACKGROUND

An unintended dural tear (DT) is the most common intraoperative complication of lumbar spine surgery. The unilateral biportal endoscopic technique (UBE) has become increasingly popular for treating various degenerative diseases of the lumbar spine; however, the DT incidence and risk factors specific to UBE remain undetermined. Therefore, this study aimed to evaluate the incidence and risk factors of DTs in UBE.

METHOD

Data from all patients who underwent UBE for degenerative lumbar spinal diseases from November 2018 to December 2021 at our institution were used to assess the effects of demographics, diagnosis, and type of surgery on unintended DT risk.

RESULTS

Overall, 24/608 patients (3.95%) experienced DTs and were treated with primary suture repair or bed rest. Although several patients experienced mild symptoms of cerebrospinal fluid (CSF) leaks, no serious postoperative sequelae such as nerve root entrapment, meningitis, or intracranial hemorrhage occurred. Additionally, no significant correlations were identified between DT and sex (P = 0.882), body mass index (BMI) (P = 0.758), smoking status (P = 0.506), diabetes (P = 0.672), hypertension (P = 0.187), or surgeon experience (P = 0.442). However, older patients were more likely to experience DT than younger patients (P = 0.034), and patients with lumbar spinal stenosis (LSS) were more likely to experience DT than patients with lumbar disc herniation (LDH) (P = 0.035). Additionally, DT was more common in revision versus primary surgery (P < 0.0001) and in unilateral laminotomy with bilateral decompression (ULBD) versus unilateral decompression (P = 0.031). Univariate logistic regression analysis revealed that age, LSS, ULBD, and revision surgery were significant risk factors for DT.

CONCLUSIONS

In this UBE cohort, we found that the incidence of DT was 3.95%. Additionally, older age, LSS, ULBD, and revision surgery significantly increased the risk of DT in UBE surgery.

Subfascial Lumbar Spine Drain Output Does Not Affect Outcomes After Incidental Durotomies in Elective Spine Surgery

OBJECTIVE

Postoperative drains have long been regarded as a preventive measure to mitigate the risks of complications such as neurological impairment by reducing fluid accumulation following spine surgery. Our study aims to contribute to the existing body of knowledge by examining the effects of postoperative drain output on the 90-day postoperative outcomes for patients who experienced an incidental durotomy after lumbar decompression procedures, with or without fusion.

METHODS

All patients aged ≥18 years with an incidental durotomy from spinal decompression with or without fusion surgery between 2017 and 2021 were retrospectively identified. The patient demographics, surgical characteristics, method of dural tear repair (DuraSeal, suture, and/or DuraGen), surgical outcomes, and drain data were collected via medical record review. Patients were grouped by readmission status and final 8-hour drain output. Those with a final 8-hour drain output of ≥40 mL were included in the high drain output (HDO) group and those with <40 mL were in the low drain output (LDO) group.

RESULTS

There were no statistically significant differences in preoperative patient demographics, surgical characteristics, method of dural tear repair, length of stay (HDO, 4.02 ± 1.90 days; vs. LDO, 4.26 ± 2.10 days; P = 0.269), hospital readmissions (HDO, 10.6%; vs. LDO, 7.96%; P = 0.744), or occurrence of reoperation during readmission (HDO, 6.06%; vs. LDO, 2.65%; P = 0.5944) between the 2 groups.

CONCLUSIONS

For patients undergoing primary lumbar decompression with or without fusion and experiencing an incidental durotomy, no significant association was found between the drain output and 90-day patient outcomes. Adequate fascial closure and the absence of symptoms may be satisfactory criteria for standard patient discharge regardless of drain output.

Delayed cerebrospinal fluid (CSF) leak following anterior cervical discectomy and fusion surgery

Background

An uncommon complication of anterior cervical discectomy and fusion (ACDF) is dura tear, which may be further complicated by cerebral spinal fluid (CSF) leak. Dural tears with CSF leak can lead to catastrophic neurologic outcomes and should be recognized early.

Case Description

This case report describes a 43-year-old female patient with history of Ehlers-Danlos syndrome who presented 1-year post-ACDF with positional headaches and lightheadedness. Imaging revealed ACDF plate subsidence and CSF leak with inferior displacement of the cerebellar tonsils.

Outcome

The patient underwent a revision procedure with removal of index screws and CSF repair using epidural blood patch, fat graft, and Tisseel. The original bicortical screws were replaced with shorter larger diameter unicortical screws. Post-operative imaging at 2 and 6 weeks confirmed resolution of CSF leak.

Conclusions

Healthcare professionals and patients undergoing spinal surgery should be aware of late presentation CSF leaks which can represent gradual decline in neurological function. Surgical candidates at risk to develop CSF leaks should be counseled about possible complications in preoperative planning.

Reoperation rate and risk factors of reoperation for ossification of the posterior longitudinal ligament (OPLL): a systematic review and meta-analysis

Revision surgery for OPLL is undesirable for both patients and physicians. However, the risk factors for reoperation are not clear. Thus, we sought to review the existing literature and determine the factors associated with higher reoperation rates in patients with OPLL. A search was performed using Pubmed, Embase, Web of Sciences, and Ovid to include studies regarding the risk factors of reoperation for OPLL. RoBANS (Risk of Bias Assessment tool for Nonrandomized Studies) was used for risk of bias analysis. Heterogeneity of studies and publication bias was assessed, and sensitivity analysis was performed. Statistical analysis was performed with a p-value < 0.05 using SPSS software (version 23). Twenty studies with 129 reoperated and 2,793 non-reoperated patients were included. The pooled reoperation rate was 5% (95% CI: 4% to 7). The most common cause of reoperation was residual OPLL or OPLL progression (n = 51, 39.53%). An increased risk of additional surgery was found with pre-operative cervical or thoracic angle (Standardized mean difference = -0.44; 95% CI: -0.69 to -0.19; p = 0.0061), post-operative CSF leak (Odds ratio, OR = 4.97; 95% CI: 2.48 to 9.96; p = 0.0005), and graft and/or hardware failure (OR = 192.09; 95% CI: 6.68 to 5521.69; p = 0.0101). Apart from the factors identified in our study, the association of other variables with the risk of second surgery could not be ruled out, owing to the complexity of the relationship and significant bias in the current literature.

The safety and effectiveness of lumbar drainage for cerebrospinal fluid leakage after spinal surgery

PURPOSE

Cerebrospinal fluid (CSF) leakage is a frequent complication after spinal surgery. The lumbar drainage procedure (LDP) is the preferred method for early closure of a dural tear. This study was conducted to assess the safety and effectiveness of LDP after spinal surgery.

MATERIALS AND METHODS

We retrospectively reviewed 122 patients (55 male and 67 female) who underwent LDP after spinal surgery between January 2010 and June 2021. LDP was performed on patients with suspected CSF leakage due to a dural tear during spinal surgery or in whom mixed-color CSF was observed in the hemo-drain after surgery. LDP was performed aseptically by a resident according to our institution's protocol, and the amount drained was from 200cc to 300cc per day. Absolute bed rest was maintained during the lumbar drainage period. The hemo-drain was opened to confirm that CSF was no longer mixed or oozing, at which time the lumbar drain was removed. Culture was performed at the drain tip when the lumbar drain was removed.

RESULTS

The spinal surgery level was cervical in 23 patients, thoracic in 27 patients, and lumbar in 72 patients. The mean duration of the indwelling lumbar drain was 7.2 days (2 days-18 days), and the mean amount of drainage was 1198.2cc (100cc-2542cc). Among the 122 patients, the CSF leakage in 101 patients was resolved with the initial procedure, but 21 patients required re-insertion. Of those 21 patients, improper insertion due to a technical problem occurred in 15 patients, poor line fixation occurred in 2 patients, and CSF leakage was again observed after removal of the lumbar drain in 4 patients. In only 1 case was open surgery done after LDP because follow-up magnetic resonance imaging showed a suspected infection. During lumbar drainage, 76 patients used antibiotics, and 46 patients did not. Four patients showed bacterial growth in the tip culture, and 3 of them had been using antibiotics. All 4 of those patients were treated without complications and discharged. Among the 122 patients, 1 patient was discharged with left hemiparesis due to cerebral venous infarction (CVI) and hemorrhage after LDP, and 1 patient underwent re-operation because the CSF collection was not resolved.

CONCLUSIONS

No major complications such as systemic infection, deep vein thrombosis, or aspiration pneumonia occurred during the lumbar drainage, except for 1 patient (0.8%) with CVI caused by over-drainage. One patient (0.8%) required open surgery after LDP, but no cases of systemic infection occurred while maintaining lumbar drainage, irrespective of antibiotic use. In conclusion, LDP is a safe and effective treatment for CSF leakage after spinal surgery.

Efficacy of patch technique for dural tear repair using hydrogel sealant: a pilot study

BACKGROUND CONTEXT

Dural tear is one of the common complications of lumbar spine surgery. Suture repair is often difficult due to the requirement of meticulous suture technique in limited space. Dural tear repair is particularly challenging in minimally invasive spine surgery. The patch technique, applying patch material and glue without suture, is an alternative method for dural tear repair.

PURPOSE

To verify the efficacy of patch technique for dural tear repair using polyethylene glycol hydrogel sealant and to compare patch materials.

STUDY DESIGN/SETTING

Basic research.

METHODS

There were three study groups: Group 1 (control group, n=4) had hydrogel sealant alone, Group 2 (n=8) had collagen sheet patch and hydrogel sealant, Group 3 (n=8) had mesh sheet patch and hydrogel sealant. A 4-mm durotomy was made in a piece of bovine dura using an arterial punch. Patch material (collagen or mesh sheet) was placed over the dural tear with 2 mm margin and then sprayed with hydrogel sealant. The pressure in the system was increased by 10 mm Hg and monitored. When the leakage occurred, the pressure threshold was measured.

RESULTS

The mean pressure threshold for leakage was 32.5 (Standard deviation=15.0), 66.3 (37.0), and 88.8 (27.5) mm Hg for Group 1, 2 and 3, respectively. The mean pressure threshold for leakage for Group 3 was significantly higher than that for Group 1 (p<.05). There was no significant difference in the mean pressure threshold for leakage between Groups 1 and 2, and Groups 2 and 3.

CONCLUSIONS

Patch technique using mesh sheet and hydrogel sealant demonstrated significantly higher mean pressure threshold for leakage compared with hydrogel sealant alone.

CLINICAL SIGNIFICANCE

Patch technique using mesh sheet and hydrogel sealant without suture is potentially a reasonable option for dural tear repair in lumbar spine surgery.

Thecal sac ligation in the setting of thoracic spondyloptosis with complete cord transection

Background

Traumatic spondyloptosis (TS) with complete spinal cord transection and unrepairable durotomy is particularly rare and can lead to a difficult-to-manage cerebrospinal fluid (CSF) leak.

Methods

We performed a systematic review of the literature on TS and discuss the management strategies and outcomes of TS with cord transection and significant dural tear. We also report a novel case of a 26-year-old female who presented with thoracic TS with complete spinal cord transection and unrepairable durotomy with high-flow CSF leak.

Results

Of 93 articles that resulted in the search query, 13 described cases of TS with complete cord transection. The approach to dural repair was only described in 8 (n = 20) of the 13 articles. The dura was not repaired in two (20%) of the cases. Ligation of the proximal end of the dural defect was done in 15 (75%) of the cases, all at the same institution. One (5%) case report describes ligation of the distal end; one (5%) case describes the repair of the dura with duraplasty; and another (5%) case describes repair using muscle graft to partially reconstruct the defect.

Conclusion

Suture ligation of the thecal sac in the setting of traumatic complete spinal cord transection with significant dural disruption has been described in the international literature and is a safe and successful technique to prevent complications associated with persisting high-flow CSF leakage. To the best of our knowledge, this is the first report of thecal sac ligation of the proximal end of the defect from the United States.

Prone Dynamic CT Myelography in Spontaneous Intracranial Hypotension : Diagnostic Need and Radiation Doses

BACKGROUND AND PURPOSE

The diagnostic work-up in patients with spontaneous intracranial hypotension (SIH) and spinal longitudinal extradural CSF collection (SLEC) on magnetic resonance imaging (MRI) comprises dynamic digital subtraction myelography (dDSM) in prone position for leak detection. Dynamic computed tomography (CT) myelography (dCT-M) in prone position follows if the leak is not unequivocally located. A drawback of dCT‑M is a high radiation dose. This study evaluates the diagnostic needs of dCT-M examinations and measures to reduce radiation doses.

METHODS

Frequency, leak sites, length and number of spiral acquisitions, DLP and effective doses of dCT‑M were retrospectively recorded in patients with ventral dural tears.

RESULTS

Of 42 patients with ventral dural tears, 8 underwent 11 dCT‑M when the leak was not unequivocally shown on digital subtraction myelography. The median number of spiral acquisitions was 4 (range 3-7) and the mean effective radiation dose 30.6 mSv (range 13.1-62.16 mSv) mSv. Five of eight leaks were located in the upper thoracic spine (range C7/Th1-Th2/3). Bolus tracking of intrathecal contrast agent in dCT‑M was used to limit the number and length of spiral acquisitions.

DISCUSSION

A dCT‑M in prone position to localize a ventral dural tear is needed in every fifth patient with a SLEC on MRI. It is typically needed when the leak is located in the upper thoracic spine and when patients have broad shoulders. Measures to reduce the radiation dose include bolus tracking or to repeat the DSM with adjusted positioning of patient.

Unrecognized dural tear during percutaneous endoscopic lumbar surgery confirmed with myelography

Iatrogenic dural tear is usually recognized during the surgery. We describe a rare case of unrecognized dural tear caused by percutaneous endoscopic lumbar surgery at another hospital clearly confirmed with dynamic myelography. Although magnetic resonance imaging of the lumbar spine showed no obvious fluid collection suggesting dural tear, dynamic myelography revealed leakage of intradural subarachnoid contrast medium along root sleeve into the intervertebral disc space. In the setting of endoscopic spine surgery, incidental dural tear might be overlooked due to the narrow and fluid-filled surgical field. Dynamic myelography is useful to evaluate the precise condition caused by unrecognized dural tear.

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

STUDY DESIGN

Retrospective cohort study.

PURPOSE

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

OVERVIEW OF LITERATURE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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.

Dural tear repair surgery comparative analysis: a stitch in time saves nine

PURPOSE

A dural tear is a common iatrogenic complication of spinal surgery associated with a several post-operative adverse events. Despite their common occurrence, guidelines on how best to repair the defect remain unclear. This study uses five post-operative outcomes to the compare repair methods used to treat 106 dural tears to determine which method is clinically favourable.

METHODS

Data were retrospectively collected from Southampton General Hospital's online databases. 106 tears were identified and grouped per repair method. MANOVA was used to compare the following five outcomes: Length of stay, numbers of further admissions or revision surgeries, length of additional admissions, post-operative infection rate and dural tear associated neurological symptoms. Sub-analysis was conducted on patient demographics, primary vs non-primary closure and type of patch. Minimal clinically important difference (MCID) was calculated via the Delphi procedure.

RESULTS

Age had a significant impact on patient outcomes and BMI displayed positive correlation with three-fifth of the predefined outcome measures. No significant difference was observed between repair groups; however, primary closure ± a patch achieved an MCID percentage improvement with regards to length of original stay, rate of additional admissions/surgeries and post-operative infection rate. Artificial over autologous patches resulted in shorter hospital stays, fewer readmissions, infections and neurological symptoms.

CONCLUSION

This study reports primary closure ± dural patch as the most efficient repair method with regards to the five reported outcomes. This study provides limited evidence in favour of artificial over autologous patches and recommends that dural patches be used in conjunction with primary closure.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

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

Study Design

A prospective comparative study.

Purpose

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

Overview of Literature

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

Methods

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

Results

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

Conclusions

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

Intraspinal pseudomeningoceles: A rare complication of spinal trauma and surgery

We present two cases of acute and delayed presentations of intraspinal pseudomeningoceles, which is a rare complication of spinal trauma or surgery. Our goal is to discuss the pathophysiology, clinical presentation, imaging findings, and treatment of this rare entity. This diagnosis should be considered in patients with unexplained neurologic symptoms in the setting of prior cervical spine injury or surgery.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A novel prefabricated patient-specific titanium cranioplasty: reconsideration from a traditional approach

OBJECTIVE

Patient-specific implants (PSI) for cranioplasty are expensive, and cost remains the limiting factor in low- to middle-income countries. The authors describe a novel, reproducible and cost-effective method of designing prefabricated titanium PSI cranioplasty.

METHODS

Ten patients from June 2018 to December 2020 were included in this retrospective study. A three-dimensional stereolithography model was made on a custom-built 3D printer with variable layer heights to produce efficient and accurate details. A certain amount of defect in the temporal region was left uncovered to avoid complications related to temporalis muscle dissection. The stereolithography model with a cranial defect was reconstructed with modelling wax. The wax model was scanned with a blue light visible scanner. The digital data was transferred to the milling machine (Jayon Surgical®, Kerala, India), where a 1-mm-thick sheet of titanium was milled according to the specifications. RFCC scoring system was used for assessing cosmetic outcome.

RESULTS

The mean duration of the surgery was 56.50 min, SD = 14.916 min (range 45-75 min). In 9/10 patients, the RFCC score was 4 points. No other complications were found at a minimum follow-up of 18 months in all patients. The cost per patient was approximately 30,000 INR or 400 US dollars. The average time required for us to get the PSI ready for surgery was about 15 days.

CONCLUSION

The authors demonstrate a novel, cost-effective and reproducible method of PSI using titanium for cranioplasty.

Outcomes and complications following minimally invasive excision of synovial cysts of the lumbar spine: A systematic review and meta-analysis

OBJECTIVE

Lumbar synovial cysts (LSC) are one of the manifestations of spinal degenerative cascade. Spinal stenosis or presence of instability in these patients can lead to various symptoms and surgery is indicated following failure of non-operative management for symptomatic synovial cysts. Surgery when performed consists of either decompression with resection of cyst with our without fusion. The efficacy and complications of minimally invasive techniques using tubular retractors (microscopic or endoscopic) in comparison to traditional open techniques remain to be studied.

METHODS

A comprehensive search of different databases was performed to retrieve studies describing the use of minimal invasive techniques using tubular retractors (both microscopic and endoscopic) in patients with LSC. Meta-analysis with subgroup analysis and metaregression was done.

RESULTS

Twenty articles were selected for the systematic review and meta-analysis with total of 388 patients. Eighty-six percent of patients (95% Confidence Interval (CI): 80-90%) had favorable outcome as per Macnab's criteria (excellent and good outcome) with the pooled standard mean difference between preoperative and postoperative Oswestry Disability Index (ODI) being -4.44 (95% CI -8.78 to -0.10, p-value=0.0474, I² 82%). The pooled percentage change in visual analogue scale (VAS) after surgery was 76.5% (95% CI 66.9-84%, I² 82%). The pooled proportion of incidental durotomies, cyst recurrence and patients requiring operation being 8% (95% CI 5-11%, I² 0%), 4% (95% CI 2-7%, I² 0%,) and 5% (95% CI 3-9%) respectively. Studies were homogeneous with an I² value of 0%. Subgroup analysis revealed no significant difference in the outcome rates or complication rates between the microscopic and endoscopic subgroups.

CONCLUSION

Minimally invasive techniques for the resection of LSC is a safe and effective alternative to traditional surgical approaches with no difference between the microscopic and endoscopic approaches.

Perspective: Early diagnosis and treatment of postoperative recurrent cerebrospinal fluid fistulas/ dural tears to avoid adhesive arachnoiditis

Background:

Intraoperative traumatic cerebrospinal fluid (CSF) fistulas/dural tears (DT) occur in up to 8.7–9.5% of primary lumbar surgical procedures. Further, they recur secondarily in between 8.1% and 17% of cases. It is critical to diagnose and treat these recurrent lumbar DT early (i.e. within 3–4 weeks of the index surgery) to avoid the evolution of adhesive arachnoiditis (AA), and its’ permanent neurological sequelae.

Methods:

Postoperative lumbar CSF fistulas/DT should be diagnosed on postoperative MR scans, and confirmed on Myelo-CT studies if needed. They should be definitively treated/occluded early on (e.g. within 3–4 postoperative weeks) to avoid the evolution of AA which can be readily diagnosed on MR studies, and corroborated, if warranted, on Myelo-CT examinations. The most prominent MR/Myelo-CT findings include; nerve roots aggregated in the central thecal sac, nerve roots peripherally scarred/adherent to the surrrounding meningeal wall (“empty thecal sac sign”), soft tissue masses in the subarachnoid space, and/or multiple loculated/scarred compartments.

Results:

Percutaneous interventional procedures (i.e. epidural blood patches, injection of fibrin glue (FG)/fibrin sealants (FS)) are rarely effective for treating postoperative recurrent lumbar CSF fistulas. Rather, direct surgical occlusion is frequently warranted including the use of; an operating microscope, adequate surgical exposure, 7-0 Gore-Tex sutures, muscle/dural patch grafts or suture anchors, followed by the application of microfibrillar collagen, and fibrin sealant/glue.

Conclusion:

Lumbar AA most commonly results from the early failure to diagnose and treat recurrent postoperative CSF fistulas. Since the clinical course of lumbar AA is typically one of progressive neurological deterioration, avoiding its’ initial onset is key.

Cranial fat dissemination following fat grafting for lumbar dural tear: First case report in the literature

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Direct fat grafting on sizable non-suturable dural tear should be avoided.

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Cranial fat dissemination can follow fat grafting for large non-suturable dural tear.

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Aseptic meningitis and hydrocephalus may result from cranial fat dissemination.

Introduction and importance

Dural tear and cerebrospinal fluid (CSF) leak is among the most common complications in lumbar spine surgery. Although primary dural suturing is the preferred method for repair, this is not always achievable specially with ventrolateral tears. Autologous fat grafting is one of the oldest and effective methods for dural repair which can also be used along with other methods of repair. This case report highlights a unique post spinal surgery complication with comment on how to avoid it. To our knowledge, this has not been previously reported in the literature.

Case presentation

The authors report a sixty-seven-year-old male with lumbar pseudomeningocele and cranial fat dissemination following fat grafting for non suturable lumbar dural tear. This was demonstrated on magnetic resonance imaging (MRI) after her presented with low-pressure headache.

Clinical discussion

Intraoperative dural tear is one of the most common complications in spinal surgery. Methods for optimal dural repair including fat grafting have been described but the choice still heavily dependent on the surgeon’s preference and experience. Fat graft can migrate leading to potential undesirable further complications like hydrocephalus and aseptic meningitis.

Conclusion

Cranial fat dissemination following fat grafting for lumbar dural tear should be recognized as a post-operative complication in lumbar spine surgery. It should be considered in case of hydrocephalus or aseptic meningitis post dural fat grafting. Surgeons should utilize adjunct methods to minimize its incidence.

Symptomatic Intracranial Hemorrhage after Dural Tear in Spinal Surgery-A Series of 10 Cases and Review of the Literature

OBJECTIVE

Intracranial hemorrhage (IH) after spinal surgery is a rare but potentially life-threatening complication. Knowledge of predisposing factors and typical clinical signs is essential for early recognition, helping to prevent an unfavorable outcome.

METHODS

A retrospective analysis was performed of patients with IH after spinal surgery treated in our institution between 2012 and 2018. The literature dealing with IH complicating spinal surgery was reviewed.

RESULTS

Our investigation found 10 patients with IH (6 female and 4 male). To the best of our knowledge, this is the largest series reported so far. The assumable incidence of IH after spinal surgery in our population was 0.0657%. Durotomy was noticed in 6 patients, all of whom were treated according to a local standard protocol. In 4 patients, the dural tear was occult. Hemorrhage occurred mostly in the cerebellar compartment. Eight of 10 patients had long-standing arterial hypertension, which seems to be a risk factor (hazard ratio, 1.58). Five patients were treated conservatively, whereas 3 required a cerebrospinal fluid (CSF) diversion procedure. In 2 patients, revision surgery with duraplasty was necessary. Seven patients were discharged with little to no neurologic symptoms, and 3 had significant deterioration. One patient died because of brainstem herniation. Review of the literature identified 54 articles with 72 patients with IH complicating spinal surgery.

CONCLUSIONS

Patients with intraoperative CSF loss should be kept under close supervision postoperatively. After opening of the dura, a watertight closure should be attempted. The use of subfascial suction drainage in cases of a dural tear as well as preexistent arterial hypertension seems to be a risk factor for the development of IH. Intracranial bleeding must be considered in every patient with unexplained neurologic deterioration after spinal surgery and should be ruled out by cranial imaging. To ensure early recognition and prevent an unfavorable outcome, a high index of suspicion is required, especially in revision spinal surgery. The treatment is specific to the extent and location of the IH, thus dictating the outcome. In most patients, conservative treatment led to a good outcome. CSF diversion measures may be necessary in patients with compression or obstruction of the fourth ventricle. Large hematomas with mass effect may require decompressive surgery.

Surgical outcomes of posterior trans-facetal decompression and stabilisation in tuberculous spondylodiscitis with neuro-deficit

STUDY DESIGN

Retrospective study.

PURPOSE

To evaluate the functional, neurological and radiological outcomes of posterior trans-facetal decompression and stabilisation in tuberculous spondylodiscitis patients with neuro-deficit.

OVERVIEW OF LITERATURE

Spinal tuberculosis mainly involves anterior column and for that anterior approach has been the most frequently used surgical technique in the past as it allows direct access to the infected tissue providing a good decompression. However, anterior surgery is associated with higher morbidity which can be reduced by posterior trans-facetal approach.

MATERIALS AND METHODS

The study included 100 Tuberculous Spondylodiscitis patients with neuro-deficit who underwent posterior trans-facetal decompression and stabilisation from 2009 to 2014. Demographic data, clinical parameters (back pain score-VAS, ODI), neurological status (Frankel's grade), radiological parameters (Kyphosis angle) and complications were evaluated.

RESULTS

Out of the total 100 patients there were 58 males and 42 females. 84 patients had thoracic and 16 had thoracolumbar region involvement. The mean age of the patients was 34.7 years. The extent of fixation was 2 segments in 52 patients and >2 segments in 48 patients. Postoperatively significant improvement in VAS (pre-op 6.5 ± 0.65 to post-op 1.73 ± 0.64) and ODI (pre-op 76.54 ± 6.96 to post-op 30.5 ± 6.56) were noted. The mean kyphosis angle was corrected from 22.33° ± 5.59° to 5.14° ± 1.32°. 86 patients showed at least 1 grade of improvement in neurology (Frankel's grading) and there was no deterioration in any patient. 3 patients developed superficial infection and 2 had an intra-operative dural tear. 94 patients showed bony fusion at 2 years follow-up.

CONCLUSION

Posterior trans-facetal decompression and stabilisation is an effective procedure in the management of thoracic & thoracolumbar tuberculous spondylodiscitis patients with neuro-deficit. It offers circumferential decompression with stabilisation and also maintains kyphosis correction.

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

BACKGROUND CONTEXT

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

PURPOSE

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

STUDY DESIGN/SETTING

A multicenter retrospective observational study.

PATIENT SAMPLE

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

OUTCOME MEASURES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pedicled Multifidus Muscle Flap To Treat Inaccessible Dural Tear In Spine Surgery: Technical Note And Preliminary Experience

OBJECTIVE

To assess the usefulness, feasibility, and limitations of pedicled multifidus muscle flaps (PMMFs) for the treatment of inaccessible dural tears during spine surgery.

METHODS

The technique of PMMF harvesting was investigated together with relevant anatomy. We prospectively evaluated 8 patients treated with the PMMF technique between January 2017 and December 2019. Results were compared with a retrospective series of 9 patients treated with a standard technique between January 2014 and December 2016. Inclusion criteria were inaccessible dural tear or dural tear judged not amenable to direct repair because of tissue loosening. Exclusion criteria were surgical treatment of intradural disease. Clinical and demographic data of all patients were collected. Clinical evaluations were performed according to American Spinal Injury Association criteria and Oswestry Disability Index. Preoperative and postoperative computed tomography was performed in all patients. The primary end point was wound healing (cerebrospinal fluid leakage, infection, and fluid collection); secondary end points were neurologic outcome and complications.

RESULTS

Control group: 1 death as a result of wound infection secondary to cerebrospinal fluid fistula and 2 patients needed lumbar subarachnoid drain; neurologic outcome: 3 patients improved and 6 were unchanged. Flap group: no wound-related complications were observed; neurologic outcome: 3 patients improved and 5 were unchanged. No flap-related complications were described. Flap harvesting was feasible in all cases, with an average 20 minutes adjunctive surgical time.

CONCLUSIONS

The PMMF technique was feasible and safe; in this preliminary experience, its use is associated with lower complications as a result of dural tears but larger series are needed to confirm its effectiveness.

Preoperative epidural steroid injections are not associated with increased rates of infection and dural tear in lumbar spine surgery

PURPOSE

The study objectives were to use a large national claims data resource to examine rates of preoperative epidural steroid injections (ESI) in lumbar spine surgery and determine whether preoperative ESI or the timing of preoperative ESI is associated with rates of postoperative complications and reoperations.

METHODS

A retrospective longitudinal analysis of patients undergoing lumbar spine surgery for disc herniation and/or spinal stenosis was undertaken using the MarketScan® databases from 2007-2015. Propensity-score matched cohorts were constructed to compare rates of complications and reoperations in patients with and without preoperative ESI.

RESULTS

Within the year prior to surgery, 120,898 (46.4%) patients had a lumber ESI. The median time between ESI and surgery was 10 weeks. 23.1% of patients having preoperative ESI had more than one level injected, and 66.5% had more than one preoperative ESI treatment. Patients with chronic pain were considerably more likely to have an ESI prior to their surgery [OR 1.62 (1.54, 1.69), p < 0.001]. Patients having preoperative ESI within in close proximity to surgery did not have increased rates of infection, dural tear, neurological complications, or surgical complications; however, they did experience higher rates of reoperations and readmissions than those with no preoperative ESI (p < 0.001).

CONCLUSION

Half of patients undergoing lumbar spine surgery for stenosis and/or herniation had a preoperative ESI. These were not associated with an increased risk for postoperative complications, even when the ESI was given in close proximity to surgery. Patients with preoperative ESI were more likely to have readmissions and reoperations following surgery.

Natural language processing for automated detection of incidental durotomy

BACKGROUND

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

PURPOSE

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

PATIENT SAMPLE

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

OUTCOME MEASURES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Dural Tears in Percutaneous Biportal Endoscopic Spine Surgery: Anatomical Location and Management

OBJECTIVE

To determine the rate and anatomical location of dural tears associated with spinal surgery using a percutaneous biportal endoscopic surgery (PBES) technique. We investigated the relationship between dural tears and the type of procedure and type of instrument used.

METHODS

We retrospectively analyzed 643 PBES cases by reviewing the medical records, operative records, and operative videos. Incidental durotomy was identified in 29 cases. We analyzed the size and anatomical location of the dural tears, the surgical instrument that caused the tear, and the technique used to seal the tear.

RESULTS

The dural tear incidence was 4.5% (29 of 643 cases). Tears in the exiting nerve area (2 cases; 6.9%) had mainly been caused by curettage, tears in the thecal sac area (18 cases; 62.1%) were associated with electric drill and forceps use; and tears in the traversing nerve area were associated with the use of a Kerrison punch (9 cases; 31%). Of the 29 cases of dural tear, 12 were treated with in-hospital monitoring and bed rest, 14 were treated with a fibrin sealant, 2 were treated with a nonpenetrating titanium clip, and 1 was converted to microscopic surgery. One case of postoperative meningocele after conservative treatment required endoscopic revision surgery to close the dural tear.

CONCLUSIONS

Most cases of incidental dural tear during PBES were treated with an endoscopic procedure. The incidence of dural tear was no greater than that associated with microscopic surgery. Our management strategy for incidental dural tears during PBES has been shown to be safe and effective.

Indirect Decompression Using Lateral Lumbar Interbody Fusion for Restenosis after an Initial Decompression Surgery

Study Design

Retrospective comparative study.

Purpose

We compared clinical and radiographical outcomes after lumbar decompression revision surgery for restenosis by lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF).

Overview of Literature

Indirect lumbar decompression with LLIF was used to treat degenerative lumbar diseases requiring neural decompression. However, only a few studies have focused on the effectiveness of this technique for restenosis after lumbar decompression.

Methods

We retrospectively investigated 52 cases involving lumbar interbody fusions for restenosis with spondylolisthesis after lumbar decompressions; these cases consisted of 15 patients who underwent indirect decompression with LLIF and posterior fixation and 37 patients who underwent the same procedure with PLIF. We compared Japanese Orthopaedic Association (JOA) scores and perioperative complications between groups. The cross-sectional areas of the thecal sac on magnetic resonance imaging were measured before, immediately after, and 2 years after surgery. We conducted statistical analyses using unpaired t -test and Fisher’s exact tests, and a p-value <0.05 was considered statistically significant.

Results

The operative time was significantly shorter in the LLIF group than in the PLIF group (115.3±33.6 min vs. 186.2±34.2 min, respectively; p<0.001). In addition, the intraoperative blood loss was significantly lower in the LLIF group than in the PLIF group (58.2±32.7 mL vs. 303.2±140.1 mL, respectively; p<0.001). We found two cases of transient lateral thigh weakness (13.3%) in the LLIF group and five cases of incidental durotomy, one case of deep infection, and one case of neurological deterioration in the PLIF group—resulting in a higher complication incidence (18.9%), although it did not reach (p=0.63). The JOA scores improved significantly in both groups.

Conclusions

Indirect decompression using LLIF provided acceptable clinical and radiographical outcomes in patients with restenosis with spondylolisthesis after lumbar decompression; no revision-surgery-specific complications were found. Our results suggest that LLIF is a safe and minimally invasive procedure for revision surgery.

True Dural Spinal Epidural Cysts: Report of 5 Cases

BACKGROUND

Spinal arachnoid cysts are a rare cause of compressive myelopathy. Spinal extradural arachnoid cysts (SEACs) are even rarer.

METHODS

We retrospectively reviewed the SEACs operated on in our hospital between 2015 and 2019, according to their clinical and radiologic findings, treatments performed, and outcomes.

RESULTS

We identified 5 cases (2 males and 3 females), ranging in age from 21 months to 78 years. Except for the pediatric case, all patients presented with pain and 3 had some grade of neurologic impairment. Preoperative magnetic resonance imaging showed multiloculated cyst in 4 cases, and the communication with the dura was properly identified in only 1 case. The patients were operated through a laminectomy or laminoplasty and total removal of the cyst, and the communication with the dura was identified and repaired in all cases. In all cases, the defect was near the exit of a nerve root, and rootlets were seen through it, producing a ball-like valve mechanism. Histology of the cyst wall showed true dura in every case. One patient needed a reoperation for evacuation of a fluid collection (related to the dural sealant). Following Odom's criteria, 3 patients had an excellent outcome and 2 had a fair outcome.

CONCLUSIONS

Total excision of a symptomatic SEAC through either laminectomy or laminoplasty is a safe and effective treatment option. Although isolated repair of the dural communication without cyst removal may seem appealing, we have found it very difficult to identify the point of communication preoperatively.

Iatrogenic lumbar giant pseudomeningocele: A report of two cases

Background:

Iatrogenic lumbar pseudomeningoceles are an uncommon complication of lumbar spinal surgeries. This pathology is an extradural, encapsulated, and cerebrospinal fluid collection which develops as a consequence of an inadvertent, unrepaired dural tear. If a pseudomeningocele grows beyond 8 cm in length, it may be classified as “giant.”

Case Description:

Two adult females with giant pseudomeningoceles due to remote lumbar laminectomy were presented. Both patients were surgically managed.

Conclusion:

Iatrogenic lumbar giant pseudomeningocele is rare. Notably, their surgical management is similar to that utilized to treat routine pseudomeningoceles.

Influence of incidental dural tears and their primary microendoscopic repairs on surgical outcomes in patients undergoing microendoscopic lumbar surgery

BACKGROUND CONTEXT

Dural tear represents a common complication of microendoscopic spine surgery that may lead to postoperative sequelae including insufficient decompression, cerebrospinal fluid fistula, intracranial hypotension, and subdural/intraparenchymal bleeding. The gold standard to manage intraoperative dural tears is primary repair. However, the downside of conversion to open surgery can be detrimental. Therefore, understanding the most appropriate strategy for microendoscopic dural repair and its impact on postoperative outcomes is of importance.

PURPOSE

The purpose of this study was to investigate the incidence of dural tears in patients undergoing microendoscopic lumbar surgery and to elucidate their influence on surgical outcomes whenever proper repair is accomplished microendoscopically without conversion to open surgery.

STUDY DESIGN/SETTING

A retrospective multicenter cohort study of prospectively enrolled patients using a propensity-matched analysis.

PATIENT SAMPLE

A total of 922 consecutive patients underwent microendoscopic surgery of the lumbar spine between February and December 2012 in the three institutions belonging to our study group.

OUTCOME MEASURES

Outcome measures included the Numeric Rating Scale for back and leg pain, Oswestry Disability Index, Japanese Orthopaedic Association score, Short Form-36, and a patients' satisfaction scale.

METHODS

All incidental dural tears were repaired by microendoscopic suture of the dura mater from inside to outside using double-arm needles and/or by fibrin glue coverage without being converted to open surgery. Surgical outcomes were compared between patients with and without dural tears using a propensity-matched analysis.

RESULTS

Microendoscopic discectomy for lumbar disc herniation was performed on 474 patients, whereas microendoscopic laminectomy and posterior lumbar interbody fusion for lumbar canal stenosis were performed on 271 and 177 patients, respectively. Dural tears occurred in 49 (5.3%) patients. Of these, 23 (2.5%) patients required suture repair, whereas the rest received a fibrin patch for a pinhole tear, all of which were successfully performed under microendoscopy. Six hundred (65.1%) patients responded pre- and postoperatively to the questionnaire. Of them, the responses of 38 patients with dural tears were compared with those of 38 matched patients. No significant differences in any outcome measures were observed between the two groups.

CONCLUSIONS

In conclusion, all dural tears in our cases were managed without conversion to open surgery and did not influence surgical outcomes.

Late-presenting dural tear: incidence, risk factors, and associated complications

BACKGROUND CONTEXT

Unrecognized and inadequately repaired intraoperative durotomies may lead to cerebrospinal fluid leak, pseudomeningocele, and other complications. Few studies have investigated durotomy that is unrecognized intraoperatively and requires additional postoperative management (hereafter, late-presenting dural tear [LPDT]), although estimates of LPDT range from 0.6 to 8.3 per 1,000 spinal surgeries. These single-center studies are based on relatively small sample sizes for an event of this rarity, all with <10 patients experiencing LPDT.

PURPOSE

This investigation is the largest yet conducted on LPDT, and sought to identify incidence, risk factors for, and complications associated with LPDT.

STUDY DESIGN/SETTING

This observational cohort study employed the American College of Surgeons National Surgical Quality Improvement Program dataset (years 2012-2015).

PATIENT SAMPLE

Patients who underwent spine surgery were identified based on presence of primary listed Current Procedural Terminology (CPT) codes corresponding to spinal fusion or isolated posterior decompression without fusion.

OUTCOME MEASURES

The primary variable in this study was occurrence of LPDT, identified as reoperation or readmission with durotomy-specific CPT or International Classification of Diseases, Ninth Revision, Clinical Modification codes but without durotomy codes present for the index procedure.

METHODS

Descriptive statistics were generated. Bivariate and multivariate analyses were conducted using chi-square tests and multiple logistic regression, respectively, generating both risk factors for LPDT and independent association of LPDT with postoperative complications. Statistical significance was defined as p<.05.

RESULTS

In total, 86,212 patients were analyzed. The overall rate of reoperation or readmission without reoperation for LPDT was 2.0 per 1,000 patients (n=174). Of LPDT patients, 97.7% required one or more unplanned reoperations (n=170), and 5.7% of patients (n=10) required two reoperations. On multivariate analysis, lumbar procedures (odds ratio [OR] 2.79, p<.0001, vs. cervical), procedures involving both cervical and lumbar levels (OR 3.78, p=.0338, vs. cervical only), procedures with decompression only (OR 1.72, p=.0017, vs. fusion and decompression), and operative duration ≥250 minutes (OR 1.70, p=.0058, vs. <250 minutes) were associated with increased likelihood of LPDT. Late-presenting dural tear was significantly associated with surgical site infection (SSI) (OR 2.54, p<.0001), wound disruption (OR 2.24, p<.0001), sepsis (OR 2.19, p<.0001), thromboembolism (OR 1.71, p<.0001), acute kidney injury (OR 1.59, p=.0281), pneumonia (OR 1.14, p=.0269), and urinary tract infection (UTI) (OR 1.08, p=.0057).

CONCLUSIONS

Late-presenting dural tears occurred in 2.0 per 1,000 patients who underwent spine surgery. Patients who underwent lumbar procedures, decompression procedures, and procedures with operative duration ≥250 minutes were at increased risk for LPDT. Further, LPDT was independently associated with increased likelihood of SSI, sepsis, pneumonia, UTI, wound dehiscence, thromboembolism, and acute kidney injury. As LPDT is associated with markedly increased morbidity and potential liability risk, spine surgeons should be aware of best-practice management for LPDT and consider it a rare, but possible etiology for developing postoperative complications.

Delayed Infected Pseudomeningocele After Percutaneous Endoscopic Lumbar Diskectomy

BACKGROUND

Percutaneous endoscopic lumbar diskectomy (PELD) has evolved over the last decades and has become an effective treatment for soft disk herniations. However, while its use increases, newer complications have been discovered.

CASE DESCRIPTION

We present the unique case of a woman who underwent PELD/foraminotomy to treat right-side foraminal disk herniations on L4-5 and L5-S1 in the same procedure. Ten days after surgery, the patient developed fever and severe low back pain radiated down her right leg. Magnetic resonance imaging showed a right pseudomeningocele arising from L4-5 and a nerve root herniated through the dural sac at the same lumbar segment. Blood cultures and fluid culture obtained from pseudomeningocele drainage depicted infection. Specific antibiotics were administrated, direct dura repair under the microscope was performed, and the patient improved symptomatically.

CONCLUSIONS

PELD combined with foraminotomy is a relatively new and skill-demanding surgery which is indicated only in cases where foraminal disk herniation is combined with foraminal stenosis. This surgical strategy requires experience by the endoscopic surgeon to prevent procedure-related complications. Although rare, these complications can lead to increased morbidity.

Intracranial Hypotension with Coma: Microsurgical Repair of a Spinal Ventral Dural Tear and Drainage of Subdural Hematoma with Intracranial Pressure Monitoring

BACKGROUND

Difficulties are associated with the diagnosis and management of patients with coma because of intracranial hypotension.

CASE DESCRIPTION

A 70-year-old man with coma (Glasgow Coma Scale score of 6) with fixed dilated pupils because of severe intracranial hypotension is described. After unsuccessful epidural blood patch (EBP), the patient underwent microsurgical dural repair and drainage of hematoma with intracranial pressure (ICP) monitoring. Intraoperatively, a dural tear associated with a cerebrospinal fluid (CSF) leak was identified at the thoracolumbar junction ventral to the spinal cord. The dural tear was repaired using posterior laminoplasty with a transdural approach without spinal fixation. Immediately after surgery, ICP was low, but it recovered to a physiologic range in 4 hours. Consciousness level favorably improved in a week, and the patient has remained stable for 1.5 years with good quality of life without recurrence.

CONCLUSIONS

The patient represents the first described case, to our knowledge, of intracranial hypotension with coma because of a CSF leak caused by a spinal ventral dural tear. In the setting of failed EBP attempt, our technique may be a treatment option for severe intracranial hypotension.

Management of Dural Tears in Endoscopic Lumbar Spinal Surgery: A Review of the Literature

OBJECTIVE

The incidental dural tear is a common complication in lumbar spine surgery. It has been reported that the incidence of dural tears is much greater in endoscopic procedures. Primary closure via suturing remains challenging in endoscopic procedures. The objective of this study was to conduct a literature review on the surgical technique for dural closure and repair in endoscopic spine surgery.

METHODS

A systematic literature search was performed using the database PubMed. In total, 12 studies reported specifically about the surgical treatment for dural tear in percutaneous and tubular assisted endoscopic technique. The dural tear rate, the technique of dural closure, postoperative time of bed rest, postoperative symptoms related to cerebrospinal fluid fistula, and revision surgery were assessed.

RESULTS

The overall rate of dural tears in endoscopic spinal surgery was 2.7%, with a range from 0% to 8.6%. The incidence of a dural tear was much greater in cases with lumbar stenosis (3.7%) than in lumbar disc herniation (2.1%). The greatest rate was accompanied by resecting synovial cysts. In addition, the risk of dural tear is greater in bilateral decompression procedures via a unilateral approach. There is no consensus about the ideal technique for dural closure in endoscopic procedures. Furthermore, there is a debate whether dural tear requires surgical treatment or not.

CONCLUSIONS

An autologous muscle or fat graft in combination with fibrin glue or a fibrin-sealed collagen sponge seems to be a good and safe method for the management of dural tear in lumbar endoscopic spine surgery.

Lumbar pseudomeningocele presenting as decerebrate rigidity-A rare case entity

INTRODUCTION

Spinal pseudomeningoceles are extradural collections of cerebrospinal fluid that result following a breach in the dural-arachnoid layer and is reported as one of the complications of lumbar disc surgery. Although they are often self subsiding and asymptomatic, they may occasionally cause low-back pain, headaches, and even nerve root entrapment. The purpose of this case report is to present an unreported presentation of pseudomeningocele PRESENTATION OF CASE: A 34 year obese male presented one month post lumbar discectomy with symptoms suggestive of raised intra cranial pressure presenting as repetitive decerebrate rigidity and altered sensorium lasting for few minutes when there is pressure on the pseudomeningocele sac and subsiding with change in position of the patient. He underwent surgical repair of the dural tear and was improved symptomatically with no recurrence of symptoms at five years follow up.

DISCUSSION

Radiological investigation helped in ruling out the other causes of decerebrate rigidity and the possible mechanism of development of such symptom in pseudomeningocele is discussed.

CONCLUSION

To the best of our knowledge, this is the first reported case of pseudomeningooele presenting as decerebrate rigidity. Spinal pseudomeningocele can present in varied ways and earliest detection is the key to avoid such complications.

Minimal invasive lumbar spine revision surgery at distance from the dura and postsurgical scar tissue: Extraforaminal Lumbar Interbody Fusion (ELIF)

Lumbar spine revision surgery is considered as challenging and related to longer operation time and complications because of the loss of anatomical landmarks and the formation of postoperative epidural fibrosis. Minimal invasive lumbar spinal surgery techniques have been refined over the last 5 years but the reexposure of the dura, the formation of postsurgical scar tissue and related dural tears remain a source of complications. For lumbar spinal revision surgery we advocate the minimal invasive Extraforaminal Lumbar Interbody Fusion (ELIF) technique. It employs a working corridor of 45° relative to the midline. This angle permits bypassing laterally the dural sac and postoperative epidural fibrosis so that dural tears do not occur. ELIF is performed without an expandable tubular retractor system, it is atraumatic following the natural intermuscular cleavage plane between the multifidus muscle and the longissimus thoracis muscle pars lumborum. Postoperatively the muscles do not show signs atrophy or fatty degeneration. In case of discectomy alone there is no need for the removal of the facets, if intracanalar lesions are targeted the partial removal of the superior facet is sufficient. ELIF represents an alternative to posterior lumbar interbody fusion (PLIF), conventional open transforaminal lumbar interbody fusion (TLIF), and minimal invasive (MIS) TLIF for lumbar spinal revision surgery.

Remote cerebellar hemorrhage caused by undetected dural tear after lumbar spinal surgery

Remote cerebellar haemorrhage is a rare but serious complication after spinal surgery. Although the mechanism is not well known, it always occurs after loss of cerebrospinal fluid due to dural tear, not always identified, which produces remote venous bleeding. Prognosis depends largely on the severity of this bleeding. We report a case of 67-year-old female who suffered a cerebellar and subarachnoid haemorrhage and subdural haematoma after elective lumbar fusion surgery and eventually required decompressive craniectomy.

Anterior Lumbar Dural Tear: A Transthecal Route for Primary Closure After Iatrogenic Durotomy

BACKGROUND

Durotomies are not infrequent in spine surgery and have increased complication rates. Primary repair is the gold standard and is feasible when access is not limited by the anatomy. A patient who presented 1 week after spinal fusion with cerebrospinal fluid (CSF) leak underwent a novel transthecal approach to repair an anterior dural tear.

OBJECTIVE

To demonstrate the feasibility, durability, and safety of a transthecal reconstruction to repair an anterior dural tear.

METHODS

A patient with spinal stenosis at L4-L5 and a spondylolisthesis at L5-S1 underwent an L4-S1 posterior lumbar interbody fusion. The procedure was complicated by a CSF leak during graft placement of the anterior dura. This location did not allow for a primary closure, and a fat graft was placed with fibrin glue. Nine days later, the patient developed postural headaches, and CSF was leaking from the wound. The patient underwent an exploration, and the most lateral aspect of the tear was visualized when retracting medially, although not enough for a primary repair. A posterior durotomy was made and the anterior dural tear was repaired from the inside.

RESULTS

The patient symptoms resolved and had radiologic improvement of the pseudomeningocele. This represents the first reported transthecal route to repair an anterior dural tear in the lumbar spine. The procedure was technically feasible, effective, and durable, with the patient having complete resolution of his CSF leak.

CONCLUSIONS

Dorsal transthecal access to the ventral aspect of the lumbar thecal sac for inadvertent anterior dural tears is a safe, feasible, and durable surgical management strategy.

Intracraneal complications after raquis surgery

Intracraneal bleeding is a rare complication after raquis surgery. It is believed to occur as a drop in the intracraneal pressure after a loss of CSF secondary to an iatrogenic dural tear. We report a patient who after surgery for lumbar stenosis presented a subarachnoid haemorrhage, an intraparenchymal haematoma, and a subdural haematoma. To our knowledge, this is the first report in the literature with such complications after this type of surgery.

Dural Tears In Patients With Depressed Skull Fractures

BACKGROUND

The presence of skull fracture in patients sustaining traumatic brain injury is an important risk factor for intracranial lesions. Assessment of integrity of dura in depressed skull fracture is of paramount importance because if dura is torn, lacerated brain matter may be present in the wound which needs proper debridement followed by water tight dural closure to prevent meningitis, cerebral abscess, and pseudomeningocoele formation. The objective of this study was to determine the frequency of dural tear in patients with depressed skull fractures.

METHODS

This cross-sectional study was conducted at Department of Neurosurgery Ayub Teaching Hospital Abbottabad. All the patients of either patients above 1 year of age with depressed skull fracture were included in this study in consecutive manner. Patients were operated for skull fractures and per-operatively dura in the region of depressed skull fracture was closely observed for any dural tear. The data were collected on a predesigned pro forma.

RESULTS

A total of 83 patients were included in this study out of which 57 (68.7%) were males and 26 (31.3%) were females. The age of the patients ranged from 1-50 (mean 15.71±13.49 years). Most common site of depressed skull fracture was parietal 32 (38.6%), followed by Frontal in 24 (28.9%), 21(25.3%) in temporal region, 5(6.0%) were in occipital region and only 1 (1.2%) in posterior fossa. Dural tear was present in 28 (33.7%) patients and it was absent in 55 (66.3%) of patients.

CONCLUSIONS

In depressed skull fractures, there are high chances of associated traumatic dural tears which should be vigilantly managed.

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.

Small bowel entrapment and ureteropelvic junction disruption associated with L3 Chance fracture-dislocation

Paediatric Chance fracture are rare lesions but often associated with abdominal injuries. We herein present the case of a seven years old patient who sustained an entrapment of small bowel and an ureteropelvic disruption associated with a Chance fracture and spine dislocation following a traffic accident. Initial X-rays and computed tomographic (CT) scan showed a Chance fracture with dislocation of L3 vertebra, with an incarceration of a small bowel loop in the spinal canal and a complete section of the left lumbar ureter. Paraplegia was noticed on the initial neurological examination. A posterior L2-L4 osteosynthesis was performed firstly. In a second time she underwent a sus umbilical laparotomy to release the incarcerated jejunum loop in the spinal canal. An end-to-end anastomosis was performed on a JJ probe to suture the left injured ureter. One month after the traumatism, she started to complain of severe headaches related to a leakage of cerebrospinalis fluid. Three months after the traumatism there was a clear regression of the leakage. One year after the trauma, an anterior intervertebral fusion was done. At final follow-up, no neurologic recovery was noticed. In case of Chance fracture, all physicians should think about abdominal injuries even if the patient is asymptomatic. Initial abdominal CT scan and magnetic resonance imaging provide in such case crucial info for management of the spine and the associated lesions.

The role of ICP monitoring in patients with persistent cerebrospinal fluid leak following spinal surgery: a case series

BACKGROUND

Cerebrospinal fluid (CSF) leak following spinal surgery is a relatively common surgical complication. A disturbance in the underlying CSF dynamics could be the causative factor in a small group of patients with refractory CSF leaks that require multiple surgical repairs and prolonged hospital admission.

METHODS

A retrospective case series of patients with persistent post spinal surgery CSF leak referred to the hydrocephalus service for continuous intracranial pressure (ICP) monitoring. Patients' notes were reviewed for medical history, ICP data, radiological data, and subsequent management and outcome.

RESULTS

Five patients (two males/three females, mean age, 35.4 years) were referred for ICP monitoring over a 12-month period. These patients had prolonged CSF leak despite multiple repair attempts 252 ± 454 days (mean ± SD). On ICP monitoring, all five patients had abnormal results, with the mean ICP 8.95 ± 4.41 mmHg. Four had abnormal pulse amplitudes, mean 6.15 mmHg ± 1.22 mmHg. All five patients underwent an intervention. Three patients underwent insertion of ventriculoperitoneal (VP) shunts. One patient had venous sinus stent insertion and one patient underwent medical management with acetazolamide. All five of the patients' CSF leak resolved post intervention. The mean time to resolution of CSF leak post intervention was 10.8  ± 12.9 days.

CONCLUSIONS

Abnormal cerebrospinal fluid dynamics could be the underlying factor in patients with a persistent and treatment-refractory CSF leak post spinal surgery. Treatments aimed at lowering ICP may be beneficial in this group of patients. Whether abnormal pressure and dynamics represent a pre-existing abnormality or is induced by spinal surgery should be a subject of further study.

Growing skull fractures: guidelines for early diagnosis and surgical management

BACKGROUND

Growing skull fracture (GSF) is a rare complication of pediatric head trauma and causes delayed onset neurological deficits and cranial defect. GSF usually develops following linear fracture with underlying dural tear resulting in herniation of the brain. Early diagnosis and treatment are essential to avoid complications. However, there are no clear-cut guidelines for the early diagnosis of GSF. The present study was conducted to identify the criteria for the early diagnosis of GSF.

MATERIAL AND METHODS

From 2010 to 2015, all pediatric patients of head trauma with linear fracture were evaluated. Patients of age <5 years with cephalhematoma, bone diastasis of 4 mm or more with underlying brain contusion were subjected to contrast brain MRI to find out the dural tear and herniation of the brain matter. Patients with contrast MRI showing dural tear and herniation of the brain matter were considered high risk for the development of GSF and treated surgically within 1 month of trauma. Patients with contrast brain MRI not showing dural tear and herniation of the brain matter were regularly followed for any signs of GSF.

RESULTS

A total of 20 patients were evaluated, out of which 16 showed dural defects with herniation of the brain matter and were subjected to duraplasty. Four patients in which MRI did not show dural tear and herniation of the brain matter were regularly followed-up and have not shown any sign of GSF later on follow-up.

CONCLUSION

Early diagnosis of GSF can be made based on the four criteria, i.e., (1) age <5 year with cephalhematoma, (2) bone diastasis 4 mm or more (3) underlying brain contusion (4) contrast MRI showing dural tear and herniation of the brain matter. Dural tear with herniation of the brain matter is the main etiopathogenic factor for the development of GSF. Early diagnosis and treatment of GSF can yield a good outcome.

The effect of incidental dural lesions on outcome after decompression surgery for lumbar spinal stenosis: results of a multi-center study with 800 patients

PURPOSE

Incidental durotomy is one of the most common complications in lumbar spine surgery. There are conflicting reports whether a dural lesion is associated with an inferior outcome after lumbar decompression. This study analyzed the effect of incidental durotomy in this specific group of patients (Dura+) and compared the results with the remaining cohort without dural laceration (Dura-).

METHODS

This prospective multi-center study included 800 patients with lumbar spinal stenosis who underwent exclusive decompression surgery. All procedures were performed as part of a multi-center investigation at three highly specialized spine clinics. Outcome measures (ODI, EQ5D, VAS_{back pain} and VAS_{leg pain}) were obtained preoperatively as well as 3 and 12 months after surgery. The effect of an incidental durotomy on the clinical outcomes was analyzed statistically between the two cohorts.

RESULTS

An intraoperative dura lesion was recorded in 6.5 % (n = 52/800) of all cases. Both cohorts (Dura+ and Dura-) did not reveal any differences regarding patient demographics, risk factors, or co-morbidities at baseline. The length of the hospital stay was significantly longer for the Dura+ cohort (8.0 vs. 6.4 days; p < 0.01). After 12 months, the Dura- cohort demonstrated a significantly greater improvement in VAS_{back pain} in comparison to the Dura+ cohort (Δ21.4 vs. Δ7.2 points; p < 0.05). The differences for the remaining outcome measures were not statistically significant (p > 0.05).

CONCLUSIONS

The results of this study reveal that an incidental durotomy was associated with a significant increase in the patient's length of stay, and risk for re-intervention for the treatment of persisting CSF leakage. In contrast to previous reports which have investigated the effects of incidental durotomies on the clinical outcome after lumbar decompression surgery, our data further suggest a possible inferior outcome in terms of low back pain improvement in the Dura+ cohort, which became clinically apparent at the 12-month follow-up period. Future studies should investigate whether a more pronounced decompression required for adequate exposure and repair of a dural laceration may, ultimately, result in increased segmental instability and in clinically undesirable low back pain.

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

Background

Incidental durotomy is a well-known complication during surgery for degenerative lumbar spinal stenosis (DLSS). In this prospective multicenter cohort study including eight medical centers our aim was to assess whether incidental durotomy during first-time lumbar spinal stenosis decompression surgery without fusion has an impact on long-term outcome.

Methods

Patients of the multi-center Lumbar Stenosis Outcome Study (LSOS) with confirmed DLSS undergoing first-time decompression without fusion were enrolled in this study. Baseline patient characteristics and outcomes were analyzed at 6, 12, and 24 months follow-up respectively with the Spinal Stenosis Measure (SSM), the Numeric Rating Scale (NRS), Feeling Thermometer (FT), the EQ-5D-EL, and the Roland and Morris Disability Questionnaire (RMDQ).

Results

A total of 167 patients met the inclusion criteria. Fifteen (9 %) of those patients had an incidental durotomy. Baseline characteristics were similar between the durotomy and no-durotomy group. All patients improved over time. In the group of durotomy patients, the median improvement in SSM symptoms scale was 1.1 points at 6 months, 1.1 points at 12 months, and 1.6 points at 24 months after baseline. For the no-durotomy group, these improvements were 0.8, 0.9, and 0.9. For SSM function the improvements were 1.0, 0.8, and 0.9 in the durotomy group, and 0.6, 0.8, and 0.8 in the no-durotomy group. None of the between-group differences were statistically significant.

Conclusions

Incidental durotomy in patients with DLSS undergoing first-time decompression surgery without fusion did not have negative effect on long-term outcome and quality of life. However, only 15 patients were included in the durotomy group but these findings remained even after adjusting for observed differences in baseline characteristics.

Symptomatic compressive pneumocephalus following lumbar decompression surgery

We report a case of symptomatic postoperative pneumocephalus after lumbar decompression. A 69-year-old man was operated on for a severe lumbar stenosis with a L2-L4 arthrodesis and a spinal decompression. No cerebrospinal fluid leakage was visible but one of the two aspirative drains was accidentally disconnected in recovery room. After 1 day, computed tomography was performed to explore intense lumbar pain and revealed a voluminous pneumorachis. Then, the patient experienced a generalized tonic-clonic seizure. Imaging revealed a voluminous pneumocephalus responsible for a significant space-occupying effect on the frontal lobe. A conservative treatment was initiated, including bed rest, oxygen therapy, neurological monitoring and anti-epileptic therapy. Symptoms gradually improved and he was discharged without any deficit after 10 days. A total radiological regression was noted in 21 days. Prevention of postoperative pneumocephalus should include a systematic repair of iatrogenic dural tear. Even in presence of severe symptomatic manifestations, a conservative treatment is possible.

Combined thrombin and autologous blood for repair of lumbar durotomy

Lumbar durotomy can be intended or unintended and can result in persistent cerebrospinal fluid (CSF) leak. Several methods are used to manage this complication including bed rest and CSF diversion. In this study, we theorize that the use of thrombin-soaked gel foam together with autologous blood laid on the sutured dural tear can prevent persistent CSF leak. A retrospective review of the records of patients who underwent lumbar surgery and had an unintended dural tear with CSF leak, comparing the outcome of patients who were submitted to thrombin-soaked gel foam together with autologous blood (group A) to patients treated by subfacial drain, tight bandage, and bed rest (group B). A total of 1371 patients had lumbar surgery, of whom 131 had dural tear. Group A included 62 patients, while group B included 69 patients. 8.1 % of group A patients had CSF leak as compared to 17.4 % of group B patients at postoperative day 14. The incidence of postoperative CSF leak and duration of postoperative hospital stay were statistically lower in group A than in group B (p < 0.05). Combining thrombin and autologous blood for repair of lumbar durotomy is an effective and a relatively cheap way to decrease CSF leak in the early postoperative period as well as decreasing postoperative hospital stay. It also resulted in decreased complications rate in the late postoperative period.