Incidental durotomy in spine surgery

Incidental dural tears during pediatric posterior spinal fusions

PURPOSE

To characterize the frequency of incidental dural tears in pediatric spine surgery, their treatment, complications, and results of long-term follow-up.

METHODS

A retrospective review of all pediatric patients who underwent a posterior spinal fusion (PSF) between 2004-2019 at a tertiary children's hospital was conducted. Electronic medical records were reviewed for patient demographics, intra-operative data, presence of an incidental dural tear, repair method, and patient outcomes.

RESULTS

3043 PSFs were reviewed, with 99 dural tears identified in 94 patients (3.3% overall incidence). Mean follow-up was 35.7 months (range 0.1-142.5). When the cause of the dural tear was specified, 69% occurred during exposure, 5% during pedicle screw placement, 4% during osteotomy, 2% during removal of implants, and 2% during intra-thecal injection of morphine. The rate of dural tears during primary PSF was significantly lower than during revision PSF procedures (2.6% vs. 6.2%, p < 0.05). 86.9% of dural tears were repaired and/or sealed intraoperatively, while 13.1% had spontaneous resolution. Postoperative headaches developed in 13.1% of patients and resolved at a mean of 7.6 days. There was no difference in the incidence of headaches in patients that were ordered bedrest vs. no bedrest (p > 0.99). Postoperative infections occurred in 9.5% of patients and 24.1% patients were identified to have undergone a revision surgery.

CONCLUSIONS

Incidence of intra-operative dural tears in pediatric spine surgery is 3.3%. Although complications associated with the dural tear occur, most resolve over time and there were no long-term sequelae in patients with 2 years of follow up.

LEVEL OF EVIDENCE

Level IV.

Perioperative Cerebrovascular Accidents in Spine Surgery: A Retrospective Descriptive Study and A Systematic Review with Meta-Analysis

Introduction

Perioperative cerebrovascular accidents (CVAs) related to spine surgery, although rare, can lead to significant disabilities. More studies on spine surgeries are required to identify those at risk of perioperative CVAs. The characteristics and outcomes of patients that experienced CVAs during spine surgery were assessed through a retrospective descriptive study and meta-analysis.

Methods

Patients aged ≥18 years who underwent spine surgery under general anesthesia at a hospital between April 2011 and March 2023 were examined. Of the 2,391 initially identified patients, 2,346 were included after excluding 45 who underwent debridement for surgical site infections. Subsequently, a meta-analysis including the present retrospective descriptive study was conducted. Databases such as PubMed and Google Scholar were searched for original peer-reviewed articles written in English.

Results

Of the 2,346 patients, 4 (0.17%) (three men, one woman) exhibited perioperative CVAs associated with spine surgery. The CVAs were diverse in nature: one case of cerebral hemorrhage resulting from dural injury during posterior occipitocervical fusion, two cases of cerebral infarctions after lumbar laminectomy and anterior thoracic fusion due to anticoagulant discontinuation, and one case of posterior reversible encephalopathy syndrome following microscopic lumbar discectomy due to gestational hypertension. The subsequent meta-analysis included three studies (n=186,860). It showed several risk factors for perioperative CVAs, including cervical level (pooled odds ratio [OR]=1.33), hypertension (pooled OR=2.27), atrial fibrillation (pooled OR=8.78), history of heart disease (pooled OR=2.47), and diabetes (pooled OR=2.13).

Conclusions

It was speculated that the potential risk factors for the four perioperative CVA cases of spine surgery in this retrospective descriptive study were intraoperative dural injury, preoperative anticoagulant discontinuation, and gestational hypertension history. The meta-analysis revealed that cervical spine surgery, hypertension, atrial fibrillation, heart disease, and diabetes increased the CVA risk. This highlights the need for risk assessment, preoperative optimization, and postoperative care to reduce spine surgery-associated perioperative CVAs.

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

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

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.

A Subdural Dissection of Cerebrospinal Fluid Causing Cauda Equina Centralization After Durotomy: A Case Report

CASE

A 61-year-old woman with recurrent left L5 radiculopathy underwent revision L4-5 decompression complicated by incidental durotomy requiring primary repair. Postoperative course was complicated by wound drainage and headache. Repeat magnetic resonance imaging demonstrated cerebrospinal fluid dissecting a plane deep to the dura mater but superficial to the arachnoid, with the collection compressing the cauda equina in an atypical horizontal and linear fashion. Nonoperative treatment was ineffective, and she required revision decompression and dural repair.

CONCLUSION

Spine surgeons should recognize this finding on postoperative imaging as a potential sign of an incomplete dural repair necessitating return to the operating room.

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.

Treatment of cerebrospinal fluid leakage with prolonged use of subfascial epidural drain and antibiotics in patients of thoracic myelopathy after posterior decompression surgery

Background

Cerebrospinal fluid leakage (CSFL) is a prevalent and vexing complication associated with spine surgery. No standard protocol is available guiding CSFL management, especially for thoracic CSFL. The aim of this study was to retrospectively evaluate the efficacy of prolonged use of subfascial epidural drain and antibiotics to treat CSFL after posterior thoracic decompression surgery.

Methods

Fifty-six patients with an average age of 52.3 years (24-76 years), who underwent thoracic decompression with CSFL (group A) and 65 patients with an average age of 54.9 years (25-80 years) without CSFL (group B) were retrospectively reviewed. Patients in group A had prolonged use of subfascial drainage and antibiotics and patients in group B were treated with conventional methods. The surgical results and rate of wound related complications was compared between the two groups.

Results

The average subfascial drainage time was 7.0 ± 2.7 days (2-16 days) and 3.8 ± 1.4 days (2-7 days) in group A and B, respectively. Higher occupation rate (>49%), presence of dural ossification and higher MRI grade (>2) were more likely to presented with CSFL. In group A, four patients (7.1%) presented with deep wound infection and were successfully managed with wound debridement or intravenous antibiotics. In group B, one patient (1.5%) had a superficial wound infection and was treated with antibiotics. No patients presented with wound dehiscence, wound exudation or CSF fistulation.

Conclusion

The occupation rate of ossified mass and presence of dural ossification were the major risk factors of CSFL. No significant difference in infection rates was observed between the patients in group A and B.

Advantages of Revision Transforaminal Full-Endoscopic Spine Surgery in Patients who have Previously Undergone Posterior Spine Surgery

BACKGROUND

 Revision lumbar spine surgery via a posterior approach is more challenging than primary surgery because of epidural or perineural scar tissue. It demands more extensive removal of the posterior structures to confirm intact bony landmarks and could cause iatrogenic instability; therefore, fusion surgery is often added. However, adjacent segment disease after fusion surgery could be a problem, and further exposure of the posterior muscles could result in multiple operated back syndrome. To address these problems, we now perform transforaminal full-endoscopic spine surgery (TF-FES) as revision surgery in patients who have previously undergone posterior lumbar surgery. There have been several reports on the advantages of TF-FES, which include feasibility of local anesthesia, minimal invasiveness to posterior structures, and less scar tissue with fewer adhesions. In this study, we aim to assess the clinical outcomes of revision TF-FES and its advantages.

METHODS

 We evaluated 48 consecutive patients with a history of posterior lumbar spine surgery who underwent revision TF-FES (at 60 levels) under local anesthesia. Intraoperative blood loss, operating time, and complication rate were evaluated. Postoperative outcomes were assessed using the modified Macnab criteria and visual analog scale (VAS) scores for leg pain, back pain, and leg numbness. We also compared the outcome of revision FES with that of primary FES.

RESULTS

 Mean operating time was 70.5 ± 14.4 (52-106) minutes. Blood loss was unmeasurable. The clinical outcomes were rated as excellent at 16 levels (26.7%), good at 28 (46.7%), fair at 10 (16.7%), and poor at 6 (10.0%). The mean preoperative VAS score was 6.0 ± 2.6 for back pain, 6.8 ± 2.4 for leg pain, and 6.3 ± 2.8 for leg numbness. At the final follow-up, the mean postoperative VAS scores for leg pain, back pain, and leg numbness were 4.3 ± 2.5, 3.8 ± 2.6, and 4.6 ± 3.2, respectively. VAS scores for all three parameters were significantly improved (p < 0.05). There was no significant difference in operating time, intraoperative blood loss, or the complication rate between revision FES and primary FES.

CONCLUSIONS

 Clinical outcomes of revision TF-FES in patients with a history of posterior lumbar spine surgery were acceptable (excellent and good in 73.4% of cases). TF-FES can preserve the posterior structures and avoid scar tissue and adhesions. Therefore, TF-FES could be an effective procedure for patients who have previously undergone posterior lumbar spine surgery.

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.

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

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

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.

Late presentation of dural tears: Two case reports and review of literature

BACKGROUND

The late presentation of dural tears (LPDT) has a low incidence rate and hidden symptoms and is easily ignored in clinical practice. If the disease is not treated in time, a series of complications may occur, including low intracranial pressure headache, infection, pseudodural cyst formation, and sinus formation. Here, we describe two cases of LPDT.

CASE SUMMARY

Two patients had sudden fever 1 wk after lumbar surgery. Physical examination showed obvious tenderness in the operation area. The patients were confirmed as having LPDT by lumbar magnetic resonance imaging and surgical exploration. One case was caused by continuous negative pressure suction and malnutrition, and the other was caused by decreased dural ductility and low postoperative nutritional status. The first symptom of both patients was fever, with occasional headache. Both patients underwent secondary surgery to treat the LPDT. Dural defects were observed and dural sealants were used to seal the dural defects, then drainage tubes were retained for drainage. After the operation, the patients were treated with antibiotics and the patients’ surgical incisions healed well, without fever or incision tenderness. Both recovered and were discharged 1 wk after the operation.

CONCLUSION

LPDT is a rare complication of spinal surgery or neurosurgery that has hidden symptoms and can easily be overlooked. Since it may cause a series of complications, LPDT needs to be actively addressed in clinical practice.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Perioperative Complications Following Spine Surgery in Adult Patients with Achondroplasia

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To describe the common types of complications and their risk factors during spine surgery in patients with achondroplasia.

METHODS

A retrospective review was performed of medical records of adult achondroplasia patients who underwent spine surgery at our institution between 2007 and 2021. Inclusion criteria were achondroplasia and age >16 years. Surgical encounters were evaluated for durotomy, postoperative neurologic deficit, wound compromise, medical complications, and return to the operating room. Statistical analysis included evaluation of relationships across complications and fisher exact test applied to bivariate/categorical variables and t-test/ANOVA for continuous variables. Multivariable analysis using logistic regression was performed to account for patient characteristics.

RESULTS

Fifty-five patients with achondroplasia underwent 95 surgeries. Forty-nine percent of the surgeries involved a complication. These included durotomy (33.7%), neurologic deficit (11.6%), wound compromise (6.3%), and other medical complications (6.3%). Thirteen percent of surgeries required return to the operating room. The greatest number of complications occurred in thoracolumbar region (60.0%) compared to cervicothoracic (18.2%) and craniocervical junction (33.3%). Chronologically later surgical encounters had decreased complications and durotomies only occurred in thoracolumbar surgeries (45.7%).

CONCLUSIONS

Adult patients with achondroplasia undergoing surgery chronologically later in this set of consecutive patients were at a decreased risk for complications. Thoracolumbar surgeries were at the greatest risk for durotomies. Male sex was a risk factor for durotomy, while age was a risk factor for neurologic deficit. The potential for adverse surgical events should be considered when evaluating patients with achondroplasia for spine surgery. .

Postoperative Intracranial Hemorrhage after an Endoscopic L5-S1 Laminectomy and Discectomy: A Case Report and Literature Review

BACKGROUND

Postoperative intracranial hemorrhage (PIH) is a fairly rare but catastrophic perioperative complication following lumbar spine surgery. This is a case report of a 54-year-old male patient who experienced PIH 2 h after an endoscopic L5-S1 laminectomy and discectomy.

CASE PRESENTATION

A 54-year-old male patient presented with right L5-S1 radiculopathy that corresponded with the picture revealed in medical imaging and the signs seen upon physical examination. Subsequently, he underwent endoscopic L5-S1 laminectomy and discectomy. The patient presented with idiopathic unconsciousness and limb twitching 2 h after surgery. An emergency cranial CT scan was obtained which demonstrated intracranial hemorrhage. Following an emergency consultation with the Department of Neurology and Neurosurgery, the patient underwent an emergency interventional thrombectomy as per their orders. The surgery was performed successfully. However, the patient's situation did not improve and he died on the second postoperative day.

CONCLUSION

PIH after spinal endoscopic surgery is a rare but horrible complication. Several factors could lead to PIH. However, in this patient, the cause of PIH might be attributed to the long operation time combined with cerebrospinal fluid (CSF) leakage. Great attention should be attached to the issue of PIH development in spinal endoscopic procedures due to constant irrigation. This study aims to highlight the issue of PIH following endoscopic spinal surgery by presenting a case report of a patient who died despite successful surgery.

Validation of a surgical drill with a haptic interface in spine surgery

Real haptics is a technology that reproduces the sense of force and touch by transmitting contact information with real objects by converting human movements and the feel of the objects into data. In recent years, real haptics technology has been installed in several surgical devices. A custom-made surgical drill was used to drill into the posterior lamina to verify the time required for penetration detection and the distance the drill advanced after penetration. A surgeon operated with the drill and the same aspects were measured and verified. All experiments were performed on female miniature pigs at 9 months of age with a mean body weight of 23.6 kg (range 9-10 months and 22.5-25.8 kg, n = 12). There were statistically significant differences in the average reaction time and the distance travelled after penetration between a handheld drill and the drill with the penetration detection function (p < 0.001). The reaction time to detect penetration and the distance after penetration were both significantly improved when compared with those of the handheld surgical drill without the penetration detection function, with mean differences of 0.049 ± 0.019 s [95% CI 0.012, 0.086 s] and 2.511 ± 0.537 mm [95% CI 1.505, 3.516 mm]. In this study, we successfully conducted a performance evaluation test of a custom-made haptic interface surgical drill. A prototype high-speed drill with a haptic interface accurately detected the penetration of the porcine posterior lamina.

Complication Avoidance in Spine Surgery

The outcomes of spine surgery are closely related to postoperative morbidity. Therefore, an experienced surgeon must be aware of various complications and should apply all necessary preventive measures to avoid them. It is widely considered that complications of spine surgery are underreported and that their real incidence is much higher than expected. This review highlights methods to prevent various types of morbidity that may be encountered during different spinal procedures, considering general complications, approach-related complications, fusion- and implant-related complications, and systemic complications.

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

INTRODUCTION AND OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Repair of cerebrospinal fluid leak during posterior thoracolumbar surgery using paraspinal muscle flap combined with fat graft

Objective

This study aimed to propose a novel surgical method via combination of fat graft and paraspinal muscle flap, in order to treat cerebrospinal fluid (CSF) leak during posterior thoracolumbar surgery. The clinical outcomes were also evaluated.

Methods

Data of a total of 71 patients who were diagnosed with intraoperative incidental durotomy and CSF leak after posterior thoracolumbar surgery in our hospital form January 2019 to January 2021 were retrospectively collected and analyzed. Among them, 34 and 37 patients were assigned into conventional suturing (CS) group and fat graft and paraspinal muscle flap (FPM) group, respectively. Patients’ demographic and clinical data were compared between the two groups.

Results

The average drainage tube time in the FPM group was 3.89 ± 1.17 days, which was shorter than that in the CS group (5.12 ± 1.56, P < 0.001). The drainage volume in the FPM group (281.08 ± 284.76 ml) was also smaller than that in the CS group (859.70 ± 553.11 ml, P < 0.001). Besides, 15 (44.11%) patients in the CS group complained of postural headache, which was more than that in the FPM group (7 patients, 18.91%). There was a statistically significant difference in postoperative visual analogue scale (VAS) score between the two groups (P = 0.013). Two patients underwent revision surgery resulting from incision nonunion and delayed meningeal cyst.

Conclusion

Fat graft combined with paraspinal muscle flap showed to be an effective method to repair CSF leak during posterior thoracolumbar surgery. The proposed method significantly reduced postoperative drainage tube time and postoperative drainage volume. It also decreased the incidence and the degree of postural headache. The proposed method showed satisfactory clinical outcomes, and it is worthy of promotion.

Delayed Symptomatic Entrapment and Herniation of Lumbar Nerve Root Due to a Prior Durotomy Defect Initially Misdiagnosed As Arachnoiditis: A Case Report

Incidental durotomies are well-known complications of spine surgery. They are often identified and repaired intraoperatively, with a preference for primary rather than secondary repair. We present the case of a middle-aged male with worsening radicular pain six months after spinal surgery complicated by a durotomy defect. His pain was worse with coughing or standing. Magnetic resonance imaging identified an L3-L5 extradural fluid collection in the lumbar spinal canal and an empty sac sign. Computed tomography lumbar myelogram identified clumping of the cauda equina nerve roots at L2-L3 and an empty sac sign at L4-L5 and L5-S1, concerning adhesions and arachnoiditis. The patient's unusual worsening of symptoms and a history of a durotomy defect with secondary repair led to suspicion of an alternative cause. Surgical exploration identified the left L5 nerve root herniated through the durotomy defect. Reduction of the nerve root herniation with primary repair of the durotomy was performed, and the patient experienced immediate relief that was stable at his one-month follow-up. This case features an unusual presentation of a delayed herniated nerve root through a prior durotomy defect with entrapment. We highlight the importance of a high degree of caution in cases of increased radicular pain following spinal surgery with a known durotomy, particularly when symptoms do not support the clinical presentation of arachnoiditis. Additionally, primary repair of durotomies should be undertaken whenever possible to avoid this potential complication.

Dural Injury Treatment with a Full-Endoscopic Transforaminal Approach: A Case Report and Description of Surgical Technique

Introduction

The objective of this study was to describe a surgical technique that uses transforaminal full-endoscopic access, which is different from the existing protocol, and to demonstrate another method of dural tear repair during endoscopic spine surgery.

Background

Endoscopic spine surgery was initially described for lumbar disc pathologies. Technical advances and new materials have made it possible to treat cervical and thoracic spinal degenerative disorders. These advances have also made it possible to treat surgical complications, notably dural tears with CSF fistulas. The literature indicates that the incidence of these injuries ranges from 1% to 17%.

Materials and Methods

Descriptive technical note of innovative and improved endoscopic surgical procedure exemplified with illustrative clinical case and comparative literature review.

Results

There is only one report describing a full-endoscopic suture technique for dural sac repair. The gold standard for treatment of the most significant nonpunctate lesions continues to be a conversion to open surgery for lesion closure. Conversion can be problematic because most surgeries are performed under sedation and local anesthesia.

Conclusions

In this case report and the new endoscopic suture technique described here, we show that primary correction of dural tears through endoscopy is possible. In addition to representing a paradigm break in solving one of the main complications of these procedures, it can expand the possibilities of spine endoscopy.

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.

Symptomatic Epidural Hematoma After Elective Cervical Spine Surgery: Incidence, Timing, Risk Factors, and Associated Complications

BACKGROUND

As the rate of elective cervical spine surgery increases, studies of complications may improve quality of care. Symptomatic postoperative cervical epidural hematomas (PCEH) are rare but result in significant morbidity. Because of their low incidence, the risk factors and complications associated with symptomatic PCEH remain unclear.

OBJECTIVE

To clarify the prevalence, timing, variables, and complications associated with PCEH following elective cervical spine surgery.

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program database, cervical spine surgeries performed between 2012 and 2016 were identified using Current Procedural Terminology codes. Symptomatic PCEH was defined as readmission or reoperation events specifically associated with International Classification of Diseases code diagnoses of postoperative hematoma within 30 d of index surgery. Multivariate models were created to assess the independent association of symptomatic PCEH with other postoperative complications.

RESULTS

There were 53233 patients included for analysis. The overall incidence of symptomatic PCEH was 0.4% (n = 198). Reoperation occurred in 158 cases (78.8%), of which 2 required a second reoperation (1.3%). The majority (91.8%) of hematomas occurred within 15 d of surgery. Multivariate analysis identified male gender, American Society of Anesthesiologists classes 3 to 5, bleeding disorder, increasing number of operative levels, revision surgery, dural repair, and perioperative transfusion as independent factors associated with PCEH. Upon controlling for those confounders, PCEH was independently associated with cardiac arrest, stroke, deep vein thrombosis, surgical site infection, and pneumonia.

CONCLUSION

Postoperative epidural hematomas requiring readmission or reoperation following elective cervical spine surgery occurred at an incidence of 0.4%. Symptomatic PCEHs are associated with increased rates of numerous major morbidities.

Posterior and postero-lateral incidental durotomy during lumbar spine surgery: primary repair versus augmented primary repair

Background

Incidental durotomy (ID) during lumbar spine surgery is a frequent complication of lumbar spine surgical procedures. Many surgical techniques were described in literature for repair of durotomy, however it is a matter of debate if one technique is a gold standard method of repair. Our study described two groups with posterior and postero-lateral ID that occurred during lumbar spine surgery: group A with 34 cases with a mean age of 49.85 years repaired by primary water tight closure using prolene or silk sutures, and group B with 34 cases with a mean age of 47.18 years treated with augmented primary repair (sutures augmented with a graft from lumbar fascia and tissue sealant "Fibrin glue"). Patients were evaluated for risk factors for durotomy, post-operative clinical outcome, and need for revision surgery.

Results

Eleven cases of group A and nine cases of group B had previous spine surgery. The dural tear was < 2 cm in 41.7% of group A and 83.3% of group B. Better outcome was achieved in 32 patients of group A and 30 patients of group B. Among our study cases 2 patients from group A and 4 patients from group B needed revision surgery due to CSF leak which failed to stop with conservative management and percutaneous blood patch.

Conclusions

Dural closure technique after ID does not seem to influence revision surgery rates due to cerebrospinal fluid (CSF) leakage and its complications. Durotomies that were immediately recognized and treated did not lead to any significant consequences.

Seizures following cervical laminectomy and lateral mass fusion: case report and review of the literature

Incidental durotomy can occur as a complication of spine surgery, which may potentially result in serious intracranial complications. We report a case of a 72 years old male with significant cervical spinal stenosis from C3 to C5 with spinal cord myelomalacia who underwent a posterior cervical decompression with instrumentation and fusion from C3-C5. An incidental dural tear was encountered during the surgery, with a sudden gush of cerebrospinal fluid (CSF) managed intraoperatively. Unfortunately, he developed generalized tonic-clonic seizures subsequently in the immediate post-operative period. Computerized tomography (CT) scan was urgently done which revealed intracranial pneumocephalus, subarachnoid hemorrhage and a right acute subdural hematoma. This case illustrates the intracranial hemorrhage potential subsequent to iatrogenic dural tear and CSF leak manifested by generalized seizures. The repair of incidental durotomy should be done immediately to decrease the amount of CSF leak and prevent any devastating effects of intracranial hemorrhage. The mechanism of this type of bleeding, risk factors and appropriate management are discussed, along with a review of the literature.

Comparison of Cost and Perioperative Outcome Profiles for Primary and Revision Posterior Cervical Fusion Procedures

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To compare perioperative outcomes and hospitalization costs between patients undergoing primary or revision posterior cervical discectomy and fusion (PCDF).

SUMMARY OF BACKGROUND DATA

While prior studies found differences in outcomes between primary and revision anterior cervical discectomy and fusion (ACDF), risk, and outcome profiles for posterior cervical revision procedures have not yet been elucidated.

METHODS

Institutional records were queried for cases involving isolated PCDF procedures to evaluate preoperative characteristics and outcomes for patients undergoing primary versus revision PCDF between 2008 and 2016. The primary outcome was perioperative complications, while perioperative and resource utilization measures such as hospitalization length, required stay in the intensive care unit (ICU), direct hospitalization costs, and 30-day emergency department (ED) admissions were explored as secondary outcomes.

RESULTS

One thousand one hundred twenty four patients underwent PCDF, with 218 (19.4%) undergoing a revision procedure. Patients undergoing revision procedures were younger (53.0 vs. 60.5 yrs), but had higher Elixhauser scores compared with the non-revision cohort. Revision cases tended to involve fewer spinal segments (3.6 vs. 4.1 segments) and shorter surgical durations (179.3 vs. 206.3 min), without significant differences in estimated blood loss. There were no significant differences in the overall complication rates (P = 0.20), however, the primary cohort had greater rates of required ICU stays (P = 0.0005) and non-home discharges (P = 0.0003). The revision cohort did experience significantly increased odds of 30-day ED admission (P = 0.04) and had higher direct hospitalization (P = 0.03) and surgical (P < 0.0001) costs.

CONCLUSION

Complication rates, including incidental durotomy, were similar between primary and revision PCDF cohorts. Although prior surgery status did not predict complication risk, comorbidity burden did. Nevertheless, patients undergoing revision procedures had decreased risk of required ICU stay but greater risk of 30-day ED admission and higher direct hospitalization and surgical costs.Level of Evidence: 3.

Nerve root herniation with entrapment in the facet joint gap after lumbar decompression surgery: a case presentation

Background

An incidental dural tear is a well-known complication during spine surgery. A rare consequence is a postoperative nerve root herniation. The purpose of this report is to describe a case of such a herniation with entrapment in the facet gap joint and to present the first MR images of this rare surgical complication.

Case presentation

We report a case of a patient who underwent lumbar decompression surgery and afterwards suffered a sudden intractable sciatica. Postoperative MRI showed a new facet joint gap effusion. During revision surgery an entrapped nerve root was found in the facet joint gap. In retrospective, the herniated nerve root is visible on postoperative MRI.

Conclusion

This case report highlights a rare complication during spine surgery. This finding is important as signs suggestive for nerve root herniation can easily be overlooked on MRI. Furthermore, this represents the first MRI documentation of this complication.

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.

Safety of Early Mobilization in Patients With Intraoperative Cerebrospinal Fluid Leak in Minimally Invasive Spine Surgery: A Case Series

BACKGROUND

Cerebrospinal fluid (CSF) leak is a common complication in spine surgery. Repairing durotomy is more difficult in the setting of minimally invasive spine surgery (MISS). Efficacy of postoperative bed rest in case of dural tear in MISS is not clear.

OBJECTIVE

To assess the safety and efficacy of our protocol of dura closure without changing access, early mobilization, and discharge in cases of intraoperative CSF leak in MISS.

METHODS

A retrospective review from 2006 to 2018 of patients who underwent MISS for degenerative and neoplastic diseases with documented accidental or intentional durotomy was conducted. The primary outcome of interest was readmission rate for repair of persistent CSF leak. Secondary outcomes captured included development of pseudomeningocele, positional headache, and subdural hematoma.

RESULTS

A total of 80 patients were identified out of 527 patients. Of these, intentional durotomy was performed in 28 patients and unintentional durotomy occurred in 52 patients. Mean follow-up period was 80.6 mo. Most of the patients were discharged on postoperative day 0 (within 4 h of surgery) without activity restrictions. A total of 2 (2.5%) patients required readmission and dural repair for continuous CSF leak and 3 patients (3.75%) developed pseudomeningocele. No lumbar drain insertion, meningitis, or subdural hematoma was reported.

CONCLUSION

Early mobilization and discharge in cases of intraoperative CSF leak in MISS appear to be safe and not associated with higher rate of complications than that of reported literature.

Dural Injury in Unilateral Biportal Endoscopic Spinal Surgery

STUDY DESIGN

Retrospective study.

OBJECTIVES

Unilateral biportal endoscopic surgery (UBES) is a popular surgical method used to treat degenerative spinal diseases because of its merits, such as reduced tissue damage and outstanding visual capacity. However, dural injury is the most common complication of UBES with an incidence rate of 1.9% to 5.8%. The purpose of this study was to analyze the pattern of dural injury during UBES and to report the clinical course.

METHODS

We retrospectively reviewed the medical and radiographic records of surgically treated patients who underwent UBES at a single institute between January 2018 and December 2019.

RESULTS

Fifty-three patients, representing 67 segments, underwent UBES. Seven dural injuries occurred, and the incidence rate was 13.2%. Among 16 far lateral approaches, 2 dural injuries of the exiting roots occurred and were treated with fibrin sealant reinforcement. Among 51 median approaches, dural injury occurred at the thecal sac (n = 3) and traversing root (n = 2). A dural injury of the shoulder of the traversing root was treated with a fibrin sealant; however, a defect in the thecal sac required a revision for reconstruction. The other 2 thecal sac injuries were directly repaired via microscopic surgery.

CONCLUSIONS

Dural injury during UBES can occur because of the various anatomical features of the meningo-vertebral ligaments. Direct repair of the central dural defect should be considered under microscopic vision. A linear tear in the lateral dura or root can be controlled with a simple patchy reinforcement under endoscopic vision.

The comparison between anterior and posterior approaches for removal of infected lumbar interbody cages and a proposal regarding the use of endoscope-assisted technique

Background

In cases of postoperative deep wound infection after interbody fusion with cages, it is often difficult to decide whether to preserve or remove the cages, and there is no consensus on the optimal approach for removing cages. The aim of this study was to investigate the surgical management of cage infection after lumbar interbody fusion.

Methods

A retrospective study was conducted between January 2012 and August 2018. Patients were included if they had postoperative deep wound infection and required cage removal. Clinical outcomes, including operative parameters, visual analog scale, neurologic status, and fusion status, were assessed and compared between anterior and posterior approaches for cage removal.

Results

Of 130 patients who developed postoperative infection and required surgical debridement, 25 (27 levels) were diagnosed with cage infection. Twelve underwent an anterior approach, while 13 underwent cage removal with a posterior approach. Significant differences were observed between the anterior and posterior approaches in elapsed time to the diagnosis of cage infection, operative time, and hospital stay. All patients had better or stationary American Spinal Injury Association impairment scale, but one case of recurrence in adjacent disc 3 months after the surgery.

Conclusions

Both anterior and posterior approaches for cage removal, followed by interbody debridement and fusion with bone grafts, were feasible methods and offered promising results. An anterior approach often requires an additional extension of posterior instrumentation due to the high incidence of concurrent pedicle screw loosening. The use of an endoscope-assisted technique is suggested to facilitate safe removal of cages.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical Outcomes of Incidental Dural Tears During Lumbar Microdiscectomy

Background: A dural tear (DT) is the most commonly encountered complication during lumbar spine surgery. The incidence of DT increases depending on the complexity of the surgical procedure and the presence of a DT is related to a poor outcome and patient satisfaction.

Objectives: This study aimed to determine the incidence and clinical outcomes of DTs in those patients who undergo lumbar disc surgery.

Methods: We retrospectively reviewed consecutive patients who underwent surgery for the management of a primary single-level lumbar disc herniation at a single institution between 2004 and 2014. Among the studied population, those with DTs were included in the study group. An age- and sex-matched group of randomly selected patients who underwent the same level and type of lumbar spine surgery, but did not develop DTs, were assigned as the control group. The outcomes were compared at 12 months postoperatively between the groups.

Results: A total of 5,476 consecutive patients (2,608 female, 2,868 male; mean age, 54 ± 11.45 [range, 21-86] years) underwent surgery for primary single-level lumbar disc herniation. DT was noted in 192 (2.85%) cases. Of these, 102 patients with complete data were included in the DT group. The DT group had a significantly increased length of hospital stay (p = 0.001). Also, the duration of bed rest in the hospital was significantly higher in patients wherein DT was repaired using hemostatic material and fibrin glue, compared to the patients with primary closure with suturing of the tear.

Conclusion: Incidental DTs, if recognized and treated appropriately, will not lead to poor clinical results and do not adversely impact postoperative outcomes.

Incidental Durotomy in Lumbar Spine Surgery; Risk Factors, Complications, and Perioperative Management

Incidental durotomy (ID) can occur in up to 14% of all lumbar spine surgeries. The risk of this complication is markedly higher among elderly patients with advanced spinal pathology. In addition, revision cases and other more invasive procedures increase the risk of ID. When unrepaired, IDs can increase the risk of developing meningitis and can lead to the formation of cerebrospinal fluid fistulas and pseudomeningoceles. Intraoperative recognition and repair are essential to ID management, although repair techniques vary considerably. Although primary suture repair is considered the "benchmark," indirect repair alone has shown comparable outcomes. Given the concern for infection after ID, many have indicated for prolonged prophylactic antibiotic regimens. However, there is little clinical evidence that this is necessary after adequate repair. The addition of subfascial drains have been shown to promote wound healing and early ambulation, whereas no consensus on duration of indwelling drains exists and such management is largely case dependent. Early ambulation after surgery has not shown to be associated with increased risk of further ID complications and decreases rehabilitation time, length of stay, and risk of venous thromboembolism. However, there remains a role for conservation mobilization protocols in more severe cases where notable symptoms are observed.

Fascia lata packing and tension suturing for symptomatic pseudomeningocele after recurrent cervical intradural tumour resection

In recurrent posterior cervical intradural tumour resections, serious complications can be developed. The dural can become affected by inflammatory factors or removed during tumor resection; if cerebrospinal fluid (CSF) leakage cannot be stopped by duraplasty, artificial meninges or fascia repair, large pseudomeningocele can develop posteriorly within the soft tissue of the neck. When the pressure of the CSF cannot be maintained steadily, persistent clinical symptoms can occur, such as postural headache or central fever. Moreover, the skin can also be penetrated in a few patients even after extension of the drainage duration, lumbar cistern drainage or skin suturing, leading to the induction of life-threatening intra-cranial infections. Is there a simple and effective surgical method to address this scenario? The aim of this study was, therefore, to investigate the effectiveness of fascia lata packing and tension suturing in the treatment of symptomatic pseudomeningocele after recurrent posterior cervical intradural tumour resection. In our study, nine consecutive spinal surgery patients were recruited from January 2008 to January 2018. All pseudomeningoceles were combined with postural headache, central neurological fever or wound non-union. There were 3 cases of melanocytoma, 3 cases of nasopharyngeal carcinoma metastasis, 2 cases of breast cancer metastasis, and 1 case of spinal canal lymphadenoma. Standard patient demographics, diagnosis, post-operative symptoms, wound healing time, and the largest pre- and last follow-up pseudomeningocele area on axial MRI sections were recorded. All cases were followed-up successfully, from 12 to 24 months, with an average of 15.3 months. Our observations indicate that all wounds healed successfully. The wound union time was 20.7 days on average. After wound union, these patients became symptom free. The largest cerebrospinal fluid area on axial MRI sections improved significantly from 42.9 ± 5.01 cm² at p re-operation to 6.6 ± 1.89 cm² at 1 year post-operation (P < 0.05); Our data indicate that .the proposed procedure is simple, safe and effective. And more importantly, it allows rapid closure of any cerebrospinal fluid leakage pools.

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.

Effectiveness of Repair Techniques for Spinal Dural Tears: A Systematic Review

BACKGROUND

Incidental or intentional durotomy in spine surgery is associated with a risk of cerebrospinal fluid (CSF) leakage and reoperation. Several strategies have been introduced, but the incomplete closure is still relatively frequent and troublesome. In this study, we review current evidence on spinal dural repair strategies and evaluate their efficacy.

METHODS

PubMed, Web of Science, and Scopus were used to search primary studies about the repair of the spinal dura with different techniques. Of 265 articles found, 11 studies, which specified repair techniques and postoperative outcomes, were included for qualitative and quantitative analysis. The primary outcomes were CSF leakage and postoperative infection.

RESULTS

The outcomes of different dural repair techniques were available in 776 cases. Pooled analysis of 11 studies demonstrated that the most commonly used technique was a combination of primary closure, patch or graft, and sealant (22.7%, 176/776). A combination of primary closure and patch or graft resulted in the lowest rate of CSF leakage (5.5%, 7/128). In this study, sealants as an adjunct to primary closure (13.7%, 18/131) did not significantly reduce the rate of CSF leakage compared with primary closure alone (17.6%, 18/102). The rates of infection and postoperative neurologic deficit were similar regardless of the repair techniques.

CONCLUSIONS

Although the use of sealants has become prevalent, available sealants as an adjunct to primary closure did not reduce the rate of CSF leakage compared with primary closure. The combination of primary closure and patches or grafts could be effective in decreasing postoperative CSF leakage.

Radiation Disrupts the Protective Function of the Spinal Meninges in a Mouse Model of Tumor-induced Spinal Cord Compression

BACKGROUND

Recent advances in multidisciplinary treatments for various cancers have extended the survival period of patients with spinal metastases. Radiotherapy has been widely used to treat spinal metastases; nevertheless, long-term survivors sometimes undergo more surgical intervention after radiotherapy because of local tumor relapse. Generally, intradural invasion of a spinal tumor seldom occurs because the dura mater serves as a tissue barrier against tumor infiltration. However, after radiation exposure, some spinal tumors invade the dura mater, resulting in leptomeningeal dissemination, intraoperative dural injury, or postoperative local recurrence. The mechanisms of how radiation might affect the dura have not been well-studied.

QUESTIONS/PURPOSES

To investigate how radiation affects the spinal meninges, we asked: (1) What is the effect of irradiation on the meningeal barrier's ability to protect against carcinoma infiltration? (2) What is the effect of irradiation on the meningeal barrier's ability to protect against sarcoma infiltration? (3) What is the effect of irradiation on dural microstructure observed by scanning electron microscopy (SEM)? (4) What is the effect of irradiation on dural microstructure observed by transmission electron microscopy (TEM)?

METHODS

Eighty-four 10-week-old female ddY mice were randomly divided into eight groups: mouse mammary tumor (MMT) implantation 6 weeks after 0-Gy irradiation (nonirradiation) (n = 11), MMT implantation 6 weeks after 20-Gy irradiation (n = 10), MMT implantation 12 weeks after nonirradiation (n = 10), MMT implantation 12 weeks after 20-Gy irradiation (n = 11), mouse osteosarcoma (LM8) implantation 6 weeks after nonirradiation (n = 11), LM8 implantation 6 weeks after 20-Gy irradiation (n = 11), LM8 implantation 12 weeks after nonirradiation (n = 10), and LM8 implantation 12 weeks after 20-Gy irradiation (n = 10); female mice were used for a mammary tumor metastasis model and ddY mice, a closed-colony mice with genetic diversity, were selected to represent interhuman diversity. Mice in each group underwent surgery to generate a tumor-induced spinal cord compression model at either 6 weeks or 12 weeks after irradiation to assess changes in the meningeal barrier's ability to protect against tumor infiltration. During surgery, the mice were implanted with MMT (representative of a carcinoma) or LM8 tumor. When the mice became paraplegic because of spinal cord compression by the growing implanted tumor, they were euthanized and evaluated histologically. Four mice died from anesthesia and 10 mice per group were euthanized (MMT-implanted groups: MMT implantation occurred 6 weeks after nonirradiation [n = 10], 6 weeks after irradiation [n = 10], 12 weeks after nonirradiation [n = 10], and 12 weeks after irradiation [n = 10]; LM8-implanted groups: LM8 implantation performed 6 weeks after nonirradiation [n = 10], 6 weeks after irradiation [n = 10], 12 weeks after nonirradiation [n = 10], and 12 weeks after irradiation [n = 10]); 80 mice were evaluated. The spines of the euthanized mice were harvested; hematoxylin and eosin staining and Masson's trichrome staining slides were prepared for histologic assessment of each specimen. In the histologic assessment, intradural invasion of the implanted tumor was graded in each group by three observers blinded to the type of tumor, presence of irradiation, and the timing of the surgery. Grade 0 was defined as no intradural invasion with intact dura mater, Grade 1 was defined as intradural invasion with linear dural continuity, and Grade 2 was defined as intradural invasion with disruption of the dural continuity. Additionally, we euthanized 12 mice for a microstructural analysis of dura mater changes by two observers blinded to the presence of irradiation. Six mice (three mice in the 12 weeks after nonirradiation group and three mice in the 12 weeks after 20-Gy irradiation group) were quantitatively analyzed for defects on the dural surface with SEM. The other six mice (three mice in the 12 weeks after nonirradiation group and three mice in the 12 weeks after 20-Gy irradiation group) were analyzed for layer structure of collagen fibers constituting dura mater by TEM. In the SEM assessment, the number and size of defects on the dural surface on images (200 μm × 300 μm) at low magnification (× 2680) were evaluated. A total of 12 images (two per mouse) were evaluated for this assessment. The days from surgery to paraplegia were compared between each of the tumor groups using the Kruskal-Wallis test. The scores of intradural tumor invasion grades and the number of defects on dural surface per SEM image were compared between irradiation group and nonirradiation group using the Mann-Whitney U test. Interobserver reliabilities of assessing intradural tumor invasion grades and the number of dural defects on the dural surface were analyzed using Fleiss'κ coefficient. P values < 0.05 were considered statistically significant.

RESULTS

There was no difference in the median (range) time to paraplegia among the MMT implantation 6 weeks after nonirradiation group, the 6 weeks after irradiation group, the 12 weeks after nonirradiation group, and the 12 weeks after irradiation group (16 days [14 to 17] versus 14 days [12 to 18] versus 16 days [14 to 17] versus 14 days [12 to 15]; χ2 = 4.7; p = 0.19). There was also no difference in the intradural invasion score between the MMT implantation 6 weeks after irradiation group and the 6 weeks after nonirradiation group (8 of 10 Grade 0 and 2 of 10 Grade 1 versus 10 of 10 Grade 0; p = 0.17). On the other hand, there was a higher intradural invasion score in the MMT implantation 12 weeks after irradiation group than the 12 weeks after nonirradiation group (5 of 10 Grade 0, 3 of 10 Grade 1 and 2 of 10 Grade 2 versus 10 of 10 Grade 0; p = 0.02). Interobserver reliability of assessing intradural tumor invasion grades in the MMT-implanted group was 0.94. There was no difference in the median (range) time to paraplegia among in the LM8 implantation 6 weeks after nonirradiation group, the 6 weeks after irradiation group, the 12 weeks after nonirradiation group, and the 12 weeks after irradiation group (12 days [9 to 13] versus 10 days [8 to 13] versus 11 days [8 to 13] versus 9 days [6 to 12]; χ2 = 2.4; p = 0.50). There was also no difference in the intradural invasion score between the LM8 implantation 6 weeks after irradiation group and the 6 weeks after nonirradiation group (7 of 10 Grade 0, 1 of 10 Grade 1 and 2 of 10 Grade 2 versus 8 of 10 Grade 0 and 2 of 10 Grade 1; p = 0.51), whereas there was a higher intradural invasion score in the LM8 implantation 12 weeks after irradiation group than the 12 weeks after nonirradiation group (3 of 10 Grade 0, 3 of 10 Grade 1 and 4 of 10 Grade 2 versus 8 of 10 Grade 0 and 2 of 10 Grade 1; p = 0.04). Interobserver reliability of assessing intradural tumor invasion grades in the LM8-implanted group was 0.93. In the microstructural analysis of the dura mater using SEM, irradiated mice had small defects on the dural surface at low magnification and degeneration of collagen fibers at high magnification. The median (range) number of defects on the dural surface per image in the irradiated mice was larger than that of nonirradiated mice (2 [1 to 3] versus 0; difference of medians, 2/image; p = 0.002) and the median size of defects was 60 μm (30 to 80). Interobserver reliability of assessing number of defects on the dural surface was 1.00. TEM revealed that nonirradiated mice demonstrated well-organized, multilayer structures, while irradiated mice demonstrated irregularly layered structures at low magnification. At high magnification, well-ordered cross-sections of collagen fibers were observed in the nonirradiated mice. However, disordered alignment of collagen fibers was observed in irradiated mice.

CONCLUSION

Intradural tumor invasion and disruptions of the dural microstructure were observed in the meninges of mice after irradiation, indicating radiation-induced disruption of the meningeal barrier.

CLINICAL RELEVANCE

We conclude that in this form of delivery, radiation is associated with disruption of the dural meningeal barrier, indicating a need to consider methods to avoid or limit Postradiation tumor relapse and spinal cord compression when treating spinal metastases so that patients do not experience intradural tumor invasion. Surgeons should be aware of the potential for intradural tumor invasion when they perform post-irradiation spinal surgery to minimize the risks for intraoperative dural injury and spinal cord injury. Further research in patients with irradiated spinal metastases is necessary to confirm that the same findings are observed in humans and to seek irradiation methods that prevent or minimize the disruption of meningeal barrier function.

Evidence that osteogenic and neurogenic differentiation capability of epidural adipose tissue-derived stem cells was more pronounced than in subcutaneous cells

Background/aim

The management of dura-related complications, such as the repairment of dural tears and reconstruction of large dural defects, remain the most challenging subjects of neurosurgery. Numerous surgical techniques and synthetic or autologous adjuvant materials have emerged as an adjunct to primary dural closure, which may result in further complications or side effects. Therefore, the subcutaneous autologous free adipose tissue graft has been recommended for the protection of the central nervous system and repairment of the meninges. In addition, human adipose tissue is also a source of multipotent stem cells. However, epidural adipose tissue seems more promising than subcutaneous because of the close location and intercellular communication with the spinal cord. Herein, it was aimed to define differentiation capability of both subcutaneous and epidural adipose tissue-derived stem cells (ASCs).

Materials and methods

Human subcutaneous and epidural adipose tissue specimens were harvested from the primary incisional site and the lumbar epidural space during lumbar spinal surgery, and ASCs were isolated.

Results

The results indicated that both types of ASCs expressed the cell surface markers, which are commonly expressed stem cells; however, epidural ASCs showed lower expression of CD90 than the subcutaneous ASCs. Moreover, it was demonstrated that the osteogenic and neurogenic differentiation capability of epidural adipose tissue-derived ASCs was more pronounced than that of the subcutaneous ASCs.

Conclusion

Consequently, the impact of characterization of epidural ASCs will allow for a new understanding for dural as well as central nervous system healing and recovery after an injury.

Dural Leak: Is It Deterrent to Outcomes in Spine Surgery?: 10 Years Retrospective Analysis of Incidence, Management Protocol, and Surgical Outcomes

STUDY DESIGN

Retrospective case-control study.

OBJECTIVES

To review the incidence of dural leaks, evaluate the efficacy of primary closure of durotomy and to study its effect on clinical outcome. The secondary aim is to classify the dural leaks and proposing a treatment algorithm for dural leaks.

SUMMARY OF BACKGROUND DATA

Dural leaks are described as one of the fearful complications in spine surgery. Literature evaluating the actual incidence, ideal treatment protocol, efficacy of primary repair techniques and its effects on long-term surgical outcomes are scanty.

METHODS

It was a retrospective analysis of 5390 consecutively operated spine cases over a period of 10 years. All cases were divided into two groups-study group (with dural leak-255) and control group (without dural leak-5135). Dural leaks were managed with the proposed treatment algorithm. Blood loss, surgical time, hospital stay, time for return to mobilization, pain free status, and clinical outcome score (ODI, VAS, NDI, and Wang criteria) were assessed in both groups at regular intervals. The statistical comparison between two groups was established with chi-square and t-tests.

RESULTS

The overall incidence of dural leaks was 4.73% with highest incidence in revision cases (27.61%). There was significant difference noted in mean surgical blood loss (P 0.001), mean hospital stay (P 0.001), time to achieve pain-free status after surgery, and return to mobilization between two groups. However, no significant difference was noted in operative time (P 0.372) and clinical outcome scores at final follow-up between the two groups.

CONCLUSION

Primary closure should be undertaken in all amenable major dural leak cases. Dural leaks managed as proposed by the author's treatment algorithm have shown a comparable clinical outcome as in patients without dural leaks. Dural leak is a friendly adverse event that does not prove a deterrent to long-term clinical outcome in spine surgeries.

LEVEL OF EVIDENCE

4.

"The eye sees only what the mind is prepared to comprehend": Unrecognized incidental findings on intraoperative computed tomography during spine instrumentation surgery

BACKGROUND

Intraoperative computed tomography (CT) is becoming more widely utilized in spine fusion surgeries. The use of CT-based image guidance has been shown to increase the accuracy in instrumentation placement and to reduce the rate of reoperation. However, incidental findings that are obvious in retrospect are still missed in spinal fusion surgeries due to the concept of inattentional blindness and surgeons' preoccupation with the main objective of intraoperative CT (i.e. instrumentation accuracy).

CASE DESCRIPTION

The first case describes a 60-year-old male who underwent posterior spinal laminectomy and interbody fusions from L2-L5. Intraoperative CT confirmed appropriate placement of hardware. However, when he was transferred out to the care unit and extubated, he developed a severe headache for which the source was confirmed to be a pneumocephalus from durotomy and cerebrospinal fluid leakage on repeat CT. A retrospective review of his intraoperative CT demonstrated the intrathecal air at L5-S1 interlaminar space that was missed on evaluation during surgery. The second case describes a 68-year-old female who was treated with a successful T4 to pelvis instrumentation and fusion with vertebral column resection at T10 confirmed with imaging. Postoperatively, she developed rapidly progressive oxygen desaturation and was found to have a pneumothorax which had been present on the intraoperative imaging.

CONCLUSION

This case report of two patients with missed intraoperative findings demonstrates the importance of looking beyond instrumentation placement and evaluating the entire intraoperative CT imaging to find abnormalities that could complicate the patients' postoperative recovery and overall hospital stay.

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Full endoscopic interlaminar discectomy (FEID) for recurrent lumbar disc herniation: surgical technique, clinical outcome, and prognostic factors

Background

The objective of this study is to determine the effectiveness and prognostic factors of revisional full endoscopic interlaminar discectomy (FEID) for recurrent herniation after conventional open disc surgery. The major concerns of the repeated discectomy for recurrent lumbar disc herniation (RLDH) are the epidural scar and postoperative segmental instability. Compared to open discectomy, endoscopic method has advantages of less tissue traumatization, clearer visualization and better tissue identification. With the improvement of endoscopic technique and instrument, the problems related to adhesive scar tissues or postoperative instability could be overcome.

Methods

From June 2014 to December 2016, FEID was performed in consecutive 24 patients for RLDH. The age ranged from 25 to 60 years (mean 44.6 years). The level operated was L5-S1 in 16 cases and L4-5 in 8 cases. To avoid injury to the neural tissue, we started with the bony structure. A small part of facet or lamina might be resected in severe stenotic or adhesive condition. Aggressive separation of the scar from the neural tissue might lead to dural tear and should be avoided. The herniated disc material was removed after neural tissue had been clearly identified and protected.

Results

The follow-up period was at least 24 months. The visual analog scale (VAS) for leg pain and back pain, and Oswestry disability index (ODI) showed significant improvement after treatment. Excellent or good outcome by the modified Macnab's criteria was obtained in 22 of 24 patients at two years follow-up. Excellent outcome was noted in 100 percent patients younger than 50 years. Small durotomy occurred in 2 patients and no visible cerebrospinal fluid (CSF) leakage was detected despite repair was not performed. Two additional surgery was performed including one repeated FEID for re-recurrence of disc herniation and one fusion surgery for postoperative back pain.

Conclusions

FEID is a safe and effective alternative for recurrent disc herniation. The successful rate was greater than 90 percent, especially in the younger patients with the advantages of early recovery and no need for fusion.

Microendoscopic discectomy versus minimally invasive transforaminal lumbar interbody fusion for lumbar spinal stenosis without spondylolisthesis

Micoendoscopic discectomy (MED) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has become alternatives of the traditional open decompression surgery alone and decompression plus fusion surgery in the treatment of lumbar spinal stenosis (LSS). To date, there is no study focusing on the comparison of clinical outcomes after MED and MIS-TLIF for LSS without spondylolisthesis.Four hundred ninety-seven patients who underwent MED (236 cases) or MIS-TLIF (261 cases) for LSS without spondylolisthesis were included in this study. Perioperative outcomes (hospital stay, operation time and blood loss), cost, functional scores (Oswestry Disability Index, 12-item short form health survey) with a 24-month follow-up visit, complication and reoperation condition within 24 months after surgery were recorded and assessed.No significant difference of clinical outcomes over time was observed between these 2 surgical approaches. Compared with MIS-TLIF, MED was associated with greater satisfaction at 1-month time point postoperatively, whereas this effect was equalized at 3-month time point postoperatively. MED brought advantages in shorter hospital stay, shorter operation time, less blood loss, and less cost over MIS-TLIF.There was no significant difference in 24-month function scores over time between MED group and MIS-TLIF group. Compared with MIS-TLIF, MED could result in a better perioperative effect and less cost.

Revision decompression with fusion as a treatment for same level restenosis after laminotomy for lumbar spinal stenosis

Background/Purpose:

Laminotomy is an established procedure to relieve symptoms of lumbar spinal stenosis. However, there is a group of patients with symptomatic recurrence. Re-decompression and fusion could be an effective salvage procedure but the results are seldom found in the literature. In this study, we focused on investigating the clinical outcomes and complication rates of revision decompression with fusion in this patient group.

Methods:

A retrospective study including patients who had undergone revision decompression with fusion for recurrent symptoms due to same level restenosis after primary laminotomy for lumbar spinal stenosis was performed. Patients with recurrent symptoms due to prolapsed intervertebral disc, trauma, infection, and neoplasm were excluded. Demographics, clinical outcomes, and complications were retrieved.

Results:

Twenty-eight patients with a total number of 42 levels of revision decompression and fusion were included. With a mean follow-up time of 27 months after revision surgery, there were statistically significant improvement of 63, 49, and 13% in Japanese Orthopaedic Association score, visual analog scale for leg pain, and Roland-Morris disability questionnaire score, respectively. There were 6(21%), 2(7%), 0(0%), and 2(7%) cases of dural tear, infection requiring reoperation, new neurological deficit, and other complications, respectively, in these revision cases.

Conclusion:

Bearing potential complications in mind, re-decompression with fusion is a viable option with reasonable clinical outcomes for patients with recurrent symptoms after laminotomy for lumbar spinal stenosis. As a treatment option for symptomatic lumbar spinal stenosis, primary laminotomy could have the potential benefit of lower complication rates in revision surgery.