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

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.

The Use of Cranial Aneurysm Clips for Repair of Incidental Lumbar Durotomy: Operative Technique and Case Series

BACKGROUND

Incidental durotomy is a common complication of posterior lumbar spine surgery; however, effective and durable methods for primary repair remain elusive. Multiple existing techniques have previously been reported and extensively described, including sutured repair and the use of nonpenetrating titanium clips. The use of cranial aneurysm clips for primary repair of lumbar durotomy serves as a safe and effective alternative to obtain watertight closure of a dural tear.

METHODS

We performed a retrospective review of patients at a single institution who underwent primary repair of an incidental lumbar durotomy with the use of an aneurysm clip during open posterior lumbar surgery between 2012 and 2023. Patient demographics, operative details, and postoperative metrics were collected and examined to evaluate the safety and efficacy of the novel technique.

RESULTS

A total of 51 patients were included for analysis. Four patients underwent durotomy repair with an aneurysm clip alone, 27 patients were repaired with an aneurysm clip and fibrin glue, and 20 patients underwent repair with an aneurysm clip, fibrin glue, and a collagen dural substitute. Three patients (5.9%) reported headaches: 2 (3.9%) with pseudomeningocele and 1 (2%) with wound leakage. Two patients (3.9%) had treatment failure with a return to the operating room for repair of a cerebrospinal fluid leak.

CONCLUSIONS

To the best of our knowledge, we report the largest series of patients undergoing primary repair of incidental durotomy with the use of an aneurysm clip. Use of an aneurysm clip is noted to be a safe, quick, and effective method of primary repair compared with existing repair techniques such as sutured repair or nonpenetrating titanium clips.

Economic Implications of Dural Tears in Lumbar Microdiscectomies: A Retrospective, Observational Study

OBJECTIVE

Dural tears (DTs) are a frequent complication after lumbar spine surgery. We sought to determine the incidence of DTs and the related impact on health care expenditures after lumbar discectomies.

METHODS

In this retrospective cohort study, all patients with first-time single-level lumbar discectomies at our institution who underwent minimally invasive surgery from 2015 to 2019 were reviewed. Age, sex, weight, height, body mass index, costs, revenues, length of stay, American Society of Anesthesiologists score, Charlson Comorbidity Index, and operative time (OT) were assessed. Exclusion criteria were age <18 years, previous spine surgery, multiple or traumatic disc herniations, and malignant and infectious diseases.

RESULTS

The follow-up time was at least 12 months postoperatively. Of 358 patients identified with lumbar discectomies, 230 met the inclusion criteria. Incidence of DTs was 3.5%. Mean costs (P < 0.001), economic loss (P < 0.01), and OT (P < 0.0001) were found to be significantly higher in the DT group compared with the control group of patients without a DT. The revenues were not statistically different between the 2 groups (P > 0.05). Further analysis of the control group by profit and loss revealed significantly higher body mass index (P < 0.05), length of stay (P < 0.0001), and OT (P < 0.0001) in the loss group.

CONCLUSIONS

DTs represent a significant socioeconomic burden in lumbar spine surgery and cause severe secondary complications. The impact of DTs on health care expenses is primarily based on significantly higher OT and a higher mean length of stay.

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.

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.

Evaluation of cefuroxime concentration in the intrathecal and extrathecal compartments of the lumbar spine-an experimental study in pigs

BACKGROUND AND PURPOSE

Optimal antibiotic prophylaxis is crucial to prevent postoperative infection in spinal surgery. Sufficient time above the minimal inhibitory concentration (fT > MIC) for relevant bacteria in target tissues is required for cefuroxime. We assessed cefuroxime concentrations and fT > MIC of 4 μg·ml-1 for Staphylococcus aureus in the intrathecal (spinal cord and cerebrospinal fluid, CSF) and extrathecal (epidural space) compartments of the lumbar spine.

EXPERIMENTAL APPROACH

Eight female pigs were anaesthetized and laminectomized at L3-L4. Microdialysis catheters were placed for sampling in the spinal cord, CSF, and epidural space. A single dose of 1500 mg cefuroxime was administered intravenously over 10 min. Microdialysates and plasma were obtained continuously during 8 h. Cefuroxime concentrations were determined by ultra-high-performance liquid chromatography.

KEY RESULTS

Mean fT > MIC (4 μg·ml-1 ) was 58 min in the spinal cord, 0 min in the CSF, 115 min in the epidural space, and 123 min in plasma. Tissue penetration was 32% in the spinal cord, 7% in the CSF, and 63% in the epidural space.

CONCLUSION AND IMPLICATIONS

fT > MIC (4 μg·ml-1 ) and tissue penetration for cefuroxime were lower in the intrathecal compartments (spinal cord and CSF) than in the extrathecal compartment (epidural space) and plasma, suggesting a significant effect of the blood-brain barrier. In terms of fT > MIC, a single dose of 1500 mg cefuroxime seems inadequate to prevent intrathecal infections related to spinal surgery for bacteria presenting with a MIC target of 4 μg· ml-1 or above.

Risk Factors and Outcomes of Central Nervous System Infection After Spinal Surgery: A Retrospective Cohort Study

OBJECTIVE

To investigate the risk factor associated with central nervous system infection, a rare and dire complication after spinal surgery.

METHODS

Univariate and multivariate logistic regression analyses were performed to screen for the independent risk factors. According to the different administration methods of antibiotics, patients were divided into intravenous and intrathecal groups. The differences in time needed for body temperature, white blood cells (WBC), and C-reactive protein (CRP) to return to normal and the time of antibiotic application were compared between the 2 groups. In addition, the differences in WBC, neutrophil ratio, CRP, procalcitonin in blood, and WBC in cerebrospinal fluid were compared before intrathecal injection, after the first one, and the last one. The incidence of complications in the 2 groups was observed.

RESULTS

Dural tears, laminectomy, and operation time >3 hours were identified as independent risk factors. The time needed for body temperature, WBC, and CRP to return to normal and the antibiotic application time were significantly different between the 2 groups (all P < 0.05). Before and after the first intrathecal injection and after the last intrathecal injection, the differences in WBCs, neutrophil ratios, CRP, procalcitonin in blood, and cerebrospinal fluid-WBC were statistically significant in overall and pairwise comparisons (P < 0.05). Complications occurred in 2 and 14 cases, respectively.

CONCLUSIONS

The independent risk factors for central nervous system infection after spinal surgery were a dural tear, laminectomy, and operation time > 3 hours. Combined intravenous and intrathecal injections of antibiotics led to a better effect than intravenous injection alone; however, this approach was associated with more complications.

Incidental Durotomy After Posterior Lumbar Decompression Surgery Associated With Increased Risk for Venous Thromboembolism

INTRODUCTION

Incidental durotomies can occur during posterior lumbar decompression surgery. Not only can this slow patient recovery but many surgeons recommend a period of bed rest in these situations, which can further slow mobilization. This immobility might be associated with increased risk of venous thromboembolism (VTE) after spinal surgery. This study aims to determine whether incidental durotomies are associated with increased risk of VTE in patients undergoing lumbar decompression surgery.

METHODS

Adult patients undergoing laminectomy or laminotomy (excluding any with concomitant fusion procedures) for degenerative etiologies and with a minimum of 90-day follow-up were identified from the MSpine Pearldiver dataset. Incidental durotomies were identified based on hospital administrative coding, and patient demographics, comorbidities, and the occurrence and timing of VTE (deep vein thrombosis [DVT] and/or pulmonary embolism) were defined. Univariate and multivariate analyses were performed.

RESULTS

Of 156,488 lumbar decompression patients included in the study, incidental durotomies was noted for 2,036 (1.3%). Markedly more VTEs were observed in the first five days in the incidental durotomies group (P < 0.001) but not incrementally any day after (P > 0.05). On univariate analyses, a significant increased risk of VTE, DVT, and PE was observed (P < 0.001 for each). On multivariate analyses controlling for age, sex, and comorbidities, odds were significantly increased for VTE (Odds ratios = 1.75, P < 0.001) and DVT (OR = 1.70, P < 0.001) but not independently significant for pulmonary embolism.

DISCUSSION

Patients who have incidental durotomies during lumbar laminectomy or laminotomy surgery were found to have increased odds of VTE, primarily in the first five days. Although not all factors associated with this could be directly determined, slower mobilization would seem to be a likely contributing factor. Increasing mobilization and/or adjusting chemoprophylaxis in this group would seem appropriately considered.

Tension Pneumocephalus Associated with Negative Pressure Wound Therapy with Instillation and Dwell Time for Methicillin-resistant Staphylococcus aureus Infection After Spinal Deformity Surgery

PURPOSE

Surgical site infection (SSI) is a serious complication after spine surgery. Recently, it has become possible to perform negative pressure wound therapy with instillation and dwell time (NPWTi-d) for postoperative infected wounds. We report the first rare case of symptomatic pneumoencephalopathy following NPWTi-d for methicillin-resistant Staphylococcus aureus (MRSA) infection after spinal deformity surgery.

METHODS

Retrospective review of a patient's medical record and imaging.

RESULTS

A 77-year-old female patient underwent posterior corrective fixation with no intraoperative complications. On the 10th postoperative day, SSI was diagnosed, and debridement was performed. Since MRSA was detected in the wound culture, and a prolonged inflammatory reaction was observed, NPWTi-d was started to preserve the instrumentation. Gradually, good granulation was observed, and the extensive soft tissue defect decreased. On the 29th day after the start of NPWTi-d, the patient experienced sudden headache and neck pain while standing, and head computed tomography led to the diagnosis of symptomatic pneumoencephalopathy. NPWTi-d was discontinued, and when surgery was performed to close the wound, dural injury was found, which was not present at the time of the initial surgery, and dural repair was performed. After 2 weeks of bed rest, the patient's pneumoencephalopathy improved. Three years have passed since the surgery, and no recurrence of cerebrospinal fluid leakage or infection has been observed.

CONCLUSIONS

Although NPWTi-d is a useful treatment for SSI, it is always necessary to pay attention to the development of pneumoencephalopathy and promptly diagnose and treat it because of the risk of life-threatening complications.

The utility of the CADISS® system in the dissection of epidural fibrosis in revision lumbar spine surgery (A case series)

Spine surgery and spinal fusion surgery are rising. Revision rates following initial surgery are between 8 and 45%. Epidural fibrosis is a common response to spine surgery for most patients and increases complications in revision surgery. Previous research suggests using MESNA (Sodium 2-mercaptoethane sulfonate) in combination with mechanical blunt dissection safely reduces surgical complications. MESNA is a mucolytic agent which selectively cleaves disulphide bonds involved in the adherence and strength of fibrosis, meaning cutting instruments are not needed. The Chemically Assisted DISSection (CADISS®) System is an optimised non-cutting surgical device, consisting of a reconstitution cartridge for MESNA preparation, irrigated surgical instruments, and a footswitch to control MESNA release. This is the first study to investigate the use of the CADISS® System in revision spine surgery.

Methods

This was a prospective, open label, observational case study. We enrolled 21 patients for revision spine surgery with the CADISS® System at two Belgium sites. The primary assessment was the number of successful removals of epidural fibrosis without cutting. The amount of MESNA used, total dissection and procedure time were recorded. For secondary criterion, the surgeons assessed global satisfaction, facilitation of dissection, quickness of action, usability, bleeding reduction and visualisation of the cleavage plane using an 11-point Likert scale (0–10). Due to the exploratory nature, no formal statistical analysis was planned. We calculated the percentage and confidence interval of successful procedures, the medians and corresponding interquartile range of the Likert criterion, and the mean (±SD) of the amount of MESNA used, CADISS® dissection time and total procedure time.

Results

24 fibrosis dissections were performed in 19 patients and 23 were successful (95.8%, CI: 78.9%; 99.9%). The mean amount of MESNA used, mean dissection time and procedure time were 16 ml (±4.94), 16.5 min (±16.1) and 86.3 min (±25.1), respectively. No dural tears were reported. The mean global satisfaction score was 9.0 (8.0–9.0). All other Likert criterion had scores of 8.0 or 9.0, excluding quickness of action, which scored 7.0 (6.0–9.0).

Conclusions

The CADISS® System in revision spine surgery has potential to effectively reduce dissection complications.

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Revision rates following initial surgery are between 8 and 45%. Epidural fibrosis is a common response to spine surgery for most patients and increases complications in revision surgery.

•

Previous research suggests using MESNA (Sodium 2-mercaptoethane sulfonate) in combination with mechanical blunt dissection safely reduces surgical complications. MESNA is a mucolytic agent which selectively cleaves disulphide bonds involved in the adherence and strength of fibrosis, meaning cutting instruments are not needed. The Chemically Assisted DISSection (CADISS®) System is an optimised non-cutting surgical device, consisting of a reconstitution cartridge for MESNA preparation, irrigated surgical instruments, and a footswitch to control MESNA release.

•

We enrolled 21 patients for revision spine surgery with the CADISS® System at two Belgium sites. The primary assessment was the number of successful removals of epidural fibrosis without cutting. The CADISS® System in revision spine surgery has potential to effectively reduce dissection complications.

Early mobilization versus bed rest for incidental durotomy: an institutional cohort study

OBJECTIVE

The aim of this study was to assess whether flat bed rest for > 24 hours after an incidental durotomy improves patient outcome or is a risk factor for medical and wound complications and longer hospital stay.

METHODS

Medical records of consecutive patients undergoing thoracic and lumbar decompression procedures from 2010 to 2020 were reviewed. Operative notes and progress notes were reviewed and searched to identify patients in whom incidental durotomies occurred. The need for revision surgery related to CSF leak or wound infection was recorded. The duration of bed rest, length of hospital stay, and complications (pulmonary, gastrointestinal, urinary, and wound) were recorded. The rates of complications were compared with regard to the duration of bed rest (≤ 24 hours vs > 24 hours).

RESULTS

A total of 420 incidental durotomies were identified, indicating a rate of 6.7% in the patient population. Of the 420 patients, 361 underwent primary repair of the dura; 254 patients were prescribed bed rest ≤ 24 hours, and 107 patients were prescribed bed rest > 24 hours. There was no statistically significant difference in the need for revision surgery (7.87% vs 8.41%, p = 0.86) between the two groups, but wound complications were increased in the prolonged bed rest group (8.66% vs 15.89%, p = 0.043). The average length of stay for patients with bed rest ≤ 24 hours was 4.47 ± 3.64 days versus 7.24 ± 4.23 days for patients with bed rest > 24 hours (p < 0.0001). There was a statistically significant increase in the frequency of ileus, urinary retention, urinary tract infections, pulmonary issues, and altered mental status in the group with prolonged bed rest after an incidental durotomy. The relative risk of complications in the group with bed rest ≤ 24 hours was 50% less than the group with > 24 hours of bed rest (RR 0.5, 95% CI 0.39-0.62; p < 0.0001).

CONCLUSIONS

In this retrospective study, the rate of revision surgery was not higher in patients with durotomy who underwent immediate mobilization, and medical complications were significantly decreased. Flat bed rest > 24 hours following incidental durotomy was associated with increased length of stay and increased rate of medical complications. After primary repair of an incidental durotomy, flat bed rest may not be necessary and appears to be associated with higher costs and complications.

Can Cervical and Lumbar Epidural Blood Patches Help Avoid Revision Surgery for Symptomatic Postoperative Dural Tears?

BACKGROUND

Incidental durotomies resulting in symptomatic postoperative cerebrospinal fluid (CSF) leaks can be treated with bedrest, subarachnoid lumbar drain, and surgical re-exploration. Another option is an epidural blood patch, which forms a clot over the dural tear in a minimally invasive manner. Our objective was to describe our center's outcomes and complications following epidural blood patches for symptomatic postoperative durotomies.

METHODS

Patients undergoing spine surgeries at one institution from 2012-2020 were included. Patient charts were reviewed for demographic information, surgical data, rate of dural tear, type of repair, and use of blood patches postoperatively.

RESULTS

A total of 1392 patients (726 male, 666 female, average age: 56.3 ± 15.4 years), including 436 cervical and 956 posterior thoracolumbar/lumbar spine surgeries were screened. There were 6 (1.4%) cervical, 64 (6.7%) lumbar, and a total of 70 (5.0%) patients with incidental dural tears/blebs. Of these patients, we identified 2 cervical and 8 lumbar spine patients with persistent CSF leaks who received epidural blood patches postoperatively. Nine of 10 (90%) had resolution of symptoms. One lumbar patient failed both an initial blood patch and subsequent surgical re-exploration, but had successful relief after a second blood patch.

CONCLUSIONS

The incidence of dural tears/blebs was 1.4% in cervical, 6.7% in lumbar, and 5.0% in all spine surgeries. Of the 10 patients with symptomatic CSF leaks, 9 were successfully treated with blood patches. Targeted epidural blood patch is effective in treating symptomatic CSF leaks and minimizes the morbidity of surgical re-exploration.

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

BACKGROUND CONTEXT

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

PURPOSE

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

STUDY DESIGN/SETTING

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

OUTCOME MEASURES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Economic Analysis of Transforaminal Lumbar Interbody Fusion Surgery Utilizing a Curved Bone Removal Device

BACKGROUND

Transforaminal lumbar interbody fusion (TLIF) represents a commonly performed spinal procedure that poses a significant financial burden on patients, hospitals and insurers. Reducing these costs, while maintaining efficacy, may be assisted by a new powered endplate preparation device, designed to shorten procedural time while offering positive impacts on other elements that contribute to the cost of care.

OBJECTIVE

The aim of the study was to assess and compare the individual cost elements of TLIF procedures with and without the use of the device, to determine whether application of this technology translated into any material procedural savings.

METHODS

The records of 208 single-level TLIF procedures in a single hospital were reviewed. Surgical time, length of hospital stay, blood loss, infection rate, and other parameters were compared for the cases where the device was used (device group; n = 143) and cases which used standard tools (control group; n = 65). The cost per unit of each element was derived from the literature, online resources, and the hospital's financial department.

RESULTS

The analysis revealed a shorter surgery duration in the device group (23 min, after controlling for procedure year and patient characteristics; statistically significant at p < 0.001) and lower complication and readmission rates (p = 0.67 and p = 0.21, respectively) associated with the use of the device, leading to a statistically significant cost reduction of approximately 2060 US dollars (US$) (p < 0.01).

CONCLUSION

The study suggests that use of the device may lead to a cost reduction and shorter procedure without deteriorating the clinical outcome.

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.

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.

Cost and Complications of Single-Level Lumbar Decompression in Those Over and Under 75: A Matched Comparison

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

This study aimed to compare costs and complication rates following single-level lumbar decompression in patients under age 75 versus patients aged 75 and older.

SUMMARY OF BACKGROUND DATA

Lumbar decompression is a common surgical treatment for lumbar pathology; however, its effectiveness can be debated in elderly patients because complication rates and costs by age group are not well-defined.

METHODS

The Medicare database was queried through the PearlDiver server for patients who underwent single-level lumbar decompression without fusion as an index procedure. The 90-day complication and reoperation rates were compared between age groups after matching for sex and comorbidity burden. Same day and 90-day costs are compared.

RESULTS

The matched cohort included 89,388 total patients (n = 44,694 for each study arm). Compared to the under 75 age group, the 75 and older age group had greater rates of deep venous thrombosis (odds ratio [OR] 1.443, P = 0.042) and dural tear (OR 1.560, P = 0.043), and a lower rate of seroma complicating the procedure (OR 0.419, P = 0.009). There was no difference in overall 90-day reoperation rate in patients under age 75 versus patients aged 75 and older (9.66% vs. 9.28%, P = 0.051), although the 75 and older age group had a greater rate of laminectomy without discectomy (CPT-63047; OR 1.175, P < 0.001), while having a lower rate of laminotomy with discectomy (CPT-63042 and CPT-63030; OR 0.727 and 0.867, respectively, P = 0.013 and <0.001, respectively). The 75 and older age group had greater same day ($3329.24 vs. $3138.05, P < 0.001) and 90-day ($5014.82 vs. $4749.44, P < 0.001) mean reimbursement.

CONCLUSION

Elderly patients experience greater rates of select perioperative complications, with mildly increased costs. There is no significant difference in overall 90-day reoperation rates.

LEVEL OF EVIDENCE

3.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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