Characterizing the presentation, management, and clinical outcomes of patients with intradural spinal chordomas: a systematic review.

OBJECTIVE: Chordomas are locally aggressive neoplasms of the spine or skull base that arise from embryonic remnants of the notochord. Intradural chordomas represent a rare subset of these neoplasms, and few studies have described intradural chordomas in the spine. This review evaluates the presentation, management, and outcomes of intradural spinal chordomas. METHODS: A systematic review of PubMed/MEDLINE, EMBASE, Cochrane Library, Scopus, and Web of Science was performed. Studies describing at least 1 case of intradural chordomas anywhere in the spine were included. Extracted details included presenting symptoms, radiological findings, treatment course, follow-up, and disease progression. RESULTS: Thirty-one studies, with a total of 41 patients, were included in this review. Seventy-six percent (31/41) of patients had primary intradural tumors, whereas 24% (10/41) presented with metastasis. The most common signs and symptoms were pain (n = 27, 66%); motor deficits (n = 20, 49%); sensory deficits (n = 17, 42%); and gait disturbance (n = 10, 24%). The most common treatment for intradural chordoma was resection and postoperative radiotherapy. Sixty-six percent (19/29) of patients reported improvement or complete resolution of symptoms after surgery. The recurrence rate was 37% (10/27), and the complication rate was 25% (6/24). The median progression-free survival was 24 months (range 4-72 months). Four patient deaths were reported. The median follow-up time was 12 months (range 13 days-84 months). CONCLUSIONS: Treatment of intradural spinal chordomas primarily involves resection and radiotherapy. A significant challenge and complication in management is spinal tumor seeding after resection, with 9 studies proposing seeding as a mechanism of tumor metastasis in 11 cases. Factors such as tumor size, Ki-67 positivity, and distant metastasis may correlate with worse outcomes and demonstrate potential as prognostic indicators for intradural spinal chordomas. Further research is needed to improve understanding of this tumor and develop optimal treatment paradigms for these patients.

Supinator to Anterior Interosseous Nerve Transfer to Restore Digital Flexion in Spinal Cord and Peripheral Nerve Injury.

PURPOSE: Restoration of pinch and grasp is a chief concern of patients with cervical spinal cord injury or peripheral nerve injury involving the anterior interosseous nerve (AIN). We hypothesize that supinator nerve-to-AIN (Sup-AIN) nerve transfer is a viable option for AIN neurotization. METHODS: We performed a retrospective review of patients who received Sup-AIN. Reported outcomes included Medical Research Council strength of the flexor digitorum profundus and flexor pollicis longus and passive range of digit motion. Patients with <12 months of follow-up were excluded. RESULTS: Eleven patients underwent Sup-AIN, eight with peripheral nerve injury, and three with spinal cord injury. Three patients were excluded because of insufficient follow-up. Average follow-up was 17 months (range: 12-25 months). Six patients had M4 recovery (75%), one patient had M3 recovery (12.5%), and one did not recover function because of severe stiffness (12.5%). We observed no complications or donor site morbidity in our patients. CONCLUSIONS: The Sup-AIN nerve transfer is an effective option to restore digital flexion in patients with peripheral nerve injury or spinal cord injury involving the AIN motor distribution. In comparison to previously described extensor carpi radialis brevis to AIN and brachialis to AIN nerve transfers, Sup-AIN offers the benefits of a more expendable donor nerve and shorter regenerative distance, respectively. The one failed Sup-AIN in our series highlights the importance of patient selection. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Development and validation of a prediction model for outcomes after transaxillary first rib resection for neurogenic thoracic outlet syndrome following strict Society for Vascular Surgery diagnostic criteria.

OBJECTIVE: Neurogenic thoracic outlet syndrome (NTOS) is the most common form of thoracic outlet syndrome. However, NTOS has remained difficult to diagnose and treat successfully. The purpose of the present study was to generate a predictive clinical calculator for postoperative outcomes after first rib resection (FRR) for NTOS. METHODS: We performed a retrospective review of patients who had undergone FRR for NTOS at a single tertiary care institution between 2016 and 2020. A multivariate stepwise logistic regression analysis was performed to assess the association of the percentage of improvement after FRR with the patient baseline characteristics, pertinent clinical characteristics, and diagnostic criteria set by the Society for Vascular Surgery. The primary outcome was subjective patient improvement after FRR. A prediction risk calculator was developed using backward stepwise multivariate logistic regression coefficients. Bootstrapping was used for internal validation. RESULTS: A total of 208 patients (22.2% male; mean age, 35.8 ± 12.8 years; median follow-up, 44.9 months) had undergone 243 FRRs. Of the 208 patients, 94.7% had had symptoms localized to the supraclavicular area, and 97.6% had had symptoms in the hand. All the patients had had positive symptoms reproduced by the elevated arm stress test and upper limb tension test. Another reasonably likely diagnosis was absent for all the patients. Of the 196 patients who had received a lidocaine injection, 180 (93.3%) had experienced improvement of NTOS symptoms. Of the 95 patients who had received a Botox injection, 82 (74.6%) had experienced improvement of NTOS symptoms. Receiver operating characteristic curve analysis was used to assess the model. The area under the curve for the backward stepwise multivariate logistic regression model was 0.8. The multivariate logistic regression analyses revealed that the significant predictors of worsened clinical outcomes included hand weakness (adjusted odds ratio [aOR], 4.28; 95% confidence interval [CI], 1.04-17.74), increasing age (aOR, 0.93; 95% CI, 0.88-0.99), workers' compensation or litigation case (aOR, 0.09; 95% CI, 0.01-0.82), and symptoms in the dominant hand (aOR, 0.20; 95% CI, 0.05-0.88). CONCLUSIONS: Using retrospective data from a single-institution database, we have developed a prediction calculator with moderate to high predictive ability, as demonstrated by an area under the curve of 0.8. The tool (available at: https://jhhntosriskcalculator.shinyapps.io/NTOS_calc/) is an important adjunct to clinical decision-making that can offer patients and providers realistic and personalized expectations of the postoperative outcome after FRR for NTOS. The findings from the present study have reinforced the diagnostic criteria set by the Society for Vascular Surgery. The calculator could aid physicians in surgical planning, referrals, and counseling patients on whether to proceed with surgery.

Approaches to Incidental Intradural Tumors of the Spine in the Pediatric Population.

BACKGROUND: Incidental intradural tumors of the spine in the pediatric population are rare lesions whose management remains unclear. Surgeons must balance the risks of iatrogenic deficits and complications after surgical resection against the risks from progressive growth of the tumor. Moreover, the natural history of an incidental finding can be difficult to predict. Here, we review the literature on incidental intradural tumors of the spine and present considerations for their management. SUMMARY: Growth of the tumor or changes in radiographic features are usually indications for resection. Asymptomatic lesions can be found in patients with genetic syndromes that predispose to tumor formation, such as neurofibromatosis type 1 and 2, schwannomatosis, and Von-Hippel-Lindau syndrome, and careful workup of a genetic cause is warranted in any patient presenting with multiple tumors and/or cutaneous features. Close follow-up is generally favored given the heavy tumor burden; however, some recommend pre-emptive resection to prevent permanent neurological deficits. Incidental intradural tumors can also occur in association with hydrocephalus, significant syringomyelia, and cord compression, and surgical treatment is usually warranted. Tumors may also be discovered as part of the workup for scoliosis, where they are not truly incidental to the scoliosis but rather are contributing to curve deformation. KEY MESSAGES: Thorough workup of patients for associated genetic syndromes or comorbidities should be undertaken in pediatric patients with incidental intradural tumors. Further research is needed into the natural history of these incidental lesions. Incidental tumors can often be managed conservatively with close follow-up, with surgical intervention warranted for expanding tumors or new-onset symptoms.

Predictors of survival and time to progression following operative management of intramedullary spinal cord astrocytomas.

PURPOSE: Surgical resection is considered standard of care for primary intramedullary astrocytomas, but the infiltrative nature of these lesions often precludes complete resection without causing new post-operative neurologic deficits. Radiotherapy and chemotherapy serve as potential adjuvants, but high-quality data evaluating their efficacy are limited. Here we analyze the experience at a single comprehensive cancer center to identify independent predictors of postoperative overall and progression-free survival. METHODS: Data was collected on patient demographics, tumor characteristics, pre-operative presentation, resection extent, long-term survival, and tumor progression/recurrence. Kaplan-Meier curves modeled overall and progression-free survival. Univariable and multivariable accelerated failure time regressions were used to compute time ratios (TR) to determine predictors of survival. RESULTS: 94 patients were included, of which 58 (62%) were alive at last follow-up. On multivariable analysis, older age (TR = 0.98; p = 0.03), higher tumor grade (TR = 0.12; p < 0.01), preoperative back pain (TR = 0.45; p < 0.01), biopsy [vs GTR] (TR = 0.18; p = 0.02), and chemotherapy (TR = 0.34; p = 0.02) were significantly associated with poorer survival. Higher tumor grade (TR = 0.34; p = 0.02) and preoperative bowel dysfunction (TR = 0.31; p = 0.02) were significant predictors of shorter time to detection of tumor growth. CONCLUSION: Tumor grade and chemotherapy were associated with poorer survival and progression-free survival. Chemotherapy regimens were highly heterogeneous, and randomized trials are needed to determine if any optimal regimens exist. Additionally, GTR was associated with improved survival, and patients should be counseled about the benefits and risks of resection extent.

Surgeon specialty effect on early outcomes of elective posterior spinal fusion for adolescent idiopathic scoliosis: a propensity-matched analysis of 965 patients.

BACKGROUND AND OBJECTIVE: Comparative effectiveness research plays a vital role in health care delivery. Specialty training is one of these variables; surgeons who are trained in different specialties may have different outcomes performing the same procedure. The objective of this study was to investigate the impact of spine surgeon specialty (neurosurgery vs orthopedic surgery) on early perioperative outcome measures of elective posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). METHODS: This is a retrospective, 1:4 propensity score-matched cohort study. 5520 AIS patients were reviewed from ACS-NSQIP pediatric database. Propensity score matching was utilized. RESULTS: Patients operated on by orthopedic surgeons were more likely to have shorter operation time (263 min vs 285 min), shorter total hospital stay (95 h vs 118 h), lower rate of return to operating room within the same admission (1.2% vs 3.8%), lower discharge rates after postoperative day 4 (23.8% vs 30.9%), and lower unplanned readmission rate (1.6% vs 4.1%), (p < 0.05). On the other hand, patients operated on by neurosurgeons had lower perioperative blood transfusion rate (62.1% vs 69.8%), (p < 0.05). Other outcome measures and mortality rates were not significantly different between the two cohorts. CONCLUSIONS: This retrospective study found significant differences in early perioperative outcomes of patients undergoing PSF for AIS by neurosurgeons and orthopedic surgeons. Further studies are recommended to corroborate this finding which may trigger changes in the educational curriculum for neurosurgery residents.

Automated prediction of the Thoracolumbar Injury Classification and Severity Score from CT using a novel deep learning algorithm.

OBJECTIVE: Damage to the thoracolumbar spine can confer significant morbidity and mortality. The Thoracolumbar Injury Classification and Severity Score (TLICS) is used to categorize injuries and determine patients at risk of spinal instability for whom surgical intervention is warranted. However, calculating this score can constitute a bottleneck in triaging and treating patients, as it relies on multiple imaging studies and a neurological examination. Therefore, the authors sought to develop and validate a deep learning model that can automatically categorize vertebral morphology and determine posterior ligamentous complex (PLC) integrity, two critical features of TLICS, using only CT scans. METHODS: All patients who underwent neurosurgical consultation for traumatic spine injury or degenerative pathology resulting in spine injury at a single tertiary center from January 2018 to December 2019 were retrospectively evaluated for inclusion. The morphology of injury and integrity of the PLC were categorized on CT scans. A state-of-the-art object detection region-based convolutional neural network (R-CNN), Faster R-CNN, was leveraged to predict both vertebral locations and the corresponding TLICS. The network was trained with patient CT scans, manually labeled vertebral bounding boxes, TLICS morphology, and PLC annotations, thus allowing the model to output the location of vertebrae, categorize their morphology, and determine the status of PLC integrity. RESULTS: A total of 111 patients were included (mean ± SD age 62 ± 20 years) with a total of 129 separate injury classifications. Vertebral localization and PLC integrity classification achieved Dice scores of 0.92 and 0.88, respectively. Binary classification between noninjured and injured morphological scores demonstrated 95.1% accuracy. TLICS morphology accuracy, the true positive rate, and positive injury mismatch classification rate were 86.3%, 76.2%, and 22.7%, respectively. Classification accuracy between no injury and suspected PLC injury was 86.8%, while true positive, false negative, and false positive rates were 90.0%, 10.0%, and 21.8%, respectively. CONCLUSIONS: In this study, the authors demonstrate a novel deep learning method to automatically predict injury morphology and PLC disruption with high accuracy. This model may streamline and improve diagnostic decision support for patients with thoracolumbar spinal trauma.

Adverse Events With the Use of rhBMP-2 in Thoracolumbar and Lumbar Spine Fusions: A 9-Year Institutional Analysis.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: To describe the adverse outcomes associated with the use of rhBMP-2 in thoracolumbar and lumbar fusions. SUMMARY OF BACKGROUND DATA: rhBMP-2 has been increasingly used in spinal fusions over the past decade. Early studies reported that the use of rhBMP-2 is associated with decreased operative time, blood loss, and pain scores, as well as improved fusion rates. Recent investigations have shown rhBMP-2 to be associated with various complications occurring at incidences ranging from 0% to 100%. METHODS: Using the institutional electronic medical records, we retrospectively reviewed all patients between January 2002 and September 2010 that underwent thoracolumbar and lumbar spine fusion with BMP. Patient demographics, operative, and outcome/complication information was collected. RESULTS: A total of 547 patient charts were reviewed with a mean follow-up time of 17 months. Mean age was 58 years. Forty-one percent of patients had undergone previous spine surgery. Thirty-nine percent of patients had a PLIF/TLIF, 29% underwent a PLF, and 20% an ALIF. No relevant differences in the patient characteristics and complications were identified between the various surgical approaches. For all approaches, having undergone a previous spine surgery was associated with increased incidence of radiculitis, reoperation, and pseudoarthrosis (P=0.005, 0.0008, 0.05, respectively) as compared with those without previous spine surgery. Being a current smoker at the time of operation was associated with increased rate of radiculitis (P=0.03) as compared with nonsmokers. CONCLUSIONS: The use of rhBMP-2, in this study, had an incidence of radiculitis, pseudoarthrosis, and reoperation that was similar to the rates in historical controls without rhBMP-2. Complications do not differ by surgical approach, but are more likely in current smokers and those undergoing revision surgery. A prospective study is warranted to further delineate the adverse event profile of rhBMP-2 and the variables that are likely to affect it (ie, type of surgery, carrier, and dose).

Quality of life outcomes following surgery for patients with coexistent cervical stenosis and multiple sclerosis.

PURPOSE: To investigate the quality of life outcomes following surgical treatment of patients with coexisting multiple sclerosis (MS) and cervical stenosis with associated myelopathy (CS). METHODS: A retrospective review of the medical records and of prospectively acquired quality of life (QOL) data was performed for all patients with symptoms of myelopathy and coexisting diagnoses of MS and CS that underwent cervical decompression surgery between 2008 and 2011. The study population was matched (1:4) to a control cohort of patients that did not have MS but presented with similar myelopathic symptoms due to cervical stenosis, were of the same age and gender, and underwent the same cervical decompression procedure within the same year. RESULTS: Sixty-five patients were reviewed, including 13 in the MS group and 52 in the control group that were followed for an average of 22 and 18 months, respectively. Whereas patients in the MS cohort remained at a Quality-Adjusted Life-Year (QALY) gain of 0.51 both pre- and post-operatively (p = 0.96), patients in the matched control cohort improved from a preoperative QALY of 0.50 to a postoperative QALY of 0.64 (p < 0.0001). The latter represents an improvement that exceeds the minimum clinically important difference. Overall, 70% of patients in the control group experienced an improvement in QALY, compared to only 54% in the MS group (p = 0.4). CONCLUSION: Patients in the control cohort had clinically and statistically significant improvements in QALY outcomes. Those in the MS cohort averaged no change in QALY. However, only a minority of MS/CS patients had worsening QALY following surgery, and as such surgery may still be considered for these patients. It is imperative that there are preoperative discussions with the MS/CS patient regarding the likelihood that surgery will only provide limited, if any, improvements in QOL.

Variations in cost calculations in spine surgery cost-effectiveness research.

OBJECT: Cost-effectiveness research in spine surgery has been a prominent focus over the last decade. However, there has yet to be a standardized method developed for calculation of costs in such studies. This lack of a standardized costing methodology may lead to conflicting conclusions on the cost-effectiveness of an intervention for a specific diagnosis. The primary objective of this study was to systematically review all cost-effectiveness studies published on spine surgery and compare and contrast various costing methodologies used. METHODS: The authors performed a systematic review of the cost-effectiveness literature related to spine surgery. All cost-effectiveness analyses pertaining to spine surgery were identified using the cost-effectiveness analysis registry database of the Tufts Medical Center Institute for Clinical Research and Health Policy, and the MEDLINE database. Each article was reviewed to determine the study subject, methodology, and results. Data were collected from each study, including costs, interventions, cost calculation method, perspective of cost calculation, and definitions of direct and indirect costs if available. RESULTS: Thirty-seven cost-effectiveness studies on spine surgery were included in the present study. Twenty-seven (73%) of the studies involved the lumbar spine and the remaining 10 (27%) involved the cervical spine. Of the 37 studies, 13 (35%) used Medicare reimbursements, 12 (32%) used a case-costing database, 3 (8%) used cost-to-charge ratios (CCRs), 2 (5%) used a combination of Medicare reimbursements and CCRs, 3 (8%) used the United Kingdom National Health Service reimbursement system, 2 (5%) used a Dutch reimbursement system, 1 (3%) used the United Kingdom Department of Health data, and 1 (3%) used the Tricare Military Reimbursement system. Nineteen (51%) studies completed their cost analysis from the societal perspective, 11 (30%) from the hospital perspective, and 7 (19%) from the payer perspective. Of those studies with a societal perspective, 14 (38%) reported actual indirect costs. CONCLUSIONS: Changes in cost have a direct impact on the value equation for concluding whether an intervention is cost-effective. It is essential to develop a standardized, accurate means of calculating costs. Comparability and transparency are essential, such that studies can be compared properly and policy makers can be appropriately informed when making decisions for our health care system based on the results of these studies.

Fractionated radiotherapy after gross-total resection of spinal chordoma: a systematic review of survival outcomes using individualized patient data.

OBJECTIVE: Spinal chordoma treatment guidelines recommend resection. However, in patients in whom gross-total resection (GTR) is achieved, the benefits of radiation therapy (RT) are unclear. Therefore, the authors performed a systematic review to determine if RT is associated with postoperative progression-free survival (PFS) or overall survival (OS) after achieving GTR of spinal chordoma. METHODS: The PubMed database was searched for studies including individualized data of patients undergoing GTR with or without RT for spinal chordoma. Patients < 18 years of age or those who underwent stereotactic body RT were excluded. Qualitative assessment was performed using Newcastle-Ottawa Scale guidelines. Log-rank tests for time-to-event data and a Cox proportional-hazards model were generated for a multivariable statistical model. RESULTS: Complete data of 132 patients were retrieved, with 37 (28%) patients receiving adjuvant RT and 95 (72%) not receiving adjuvant RT. The mean follow-up was not statistically significantly different between those undergoing RT and not undergoing RT (54.02 months and 65.43 months, respectively). Patients were more likely not to undergo RT if their disease was located in the sacrum versus the mobile spine (p < 0.001). When controlling for age ≥ 65 years, male sex, disease location, and treatment year ≥ 2010, patients undergoing RT had similar PFS and OS when compared with those not undergoing RT on multivariable survival analysis (HR 0.935 [95% CI 0.703-2.340], p = 0.844 and HR 2.078 [95% CI 0.848-5.090], p = 0.110, respectively). However, age ≥ 65 years was associated with poorer OS in adjusted analyses (HR 2.761 [95% CI 1.185-6.432], p = 0.018) relative to patients < 65 years of age. CONCLUSIONS: After achieving GTR of spinal chordoma, the utility of RT on PFS and OS remains unclear. Age ≥ 65 years appears to be associated with OS in spinal chordoma patients. Additional multicenter prospective studies are needed to determine the utility of RT in this patient population.

Nondysraphic Intramedullary Spinal Cord Lipomas in the Adult Population.

OBJECTIVE: Intramedullary spinal cord lipomas without spinal dysraphism are rare. Although they are benign tumors, they can cause significant neurological deficits. Their tight adherence to the spinal cord presents a challenge for resection. Therefore, we review our institutional experience treating adult patients with intramedullary lipomas in the absence of dysraphism and report long-term outcomes after resection. METHODS: All adult patients undergoing resection of intramedullary spinal cord lipomas at a comprehensive cancer center between June 2011 and June 2023 were retrospectively identified. Patients with spinal dysraphism or extramedullary lipomas were excluded. Patients were included if they had microscopic surgical debulking with tissue sampling confirming the diagnosis. RESULTS: Six patients were identified with a mean age of 35.0 ± 11.5 years, and 67% were female. Four cases localized to the thoracic spine. Symptoms included pain, numbness, and lower extremity motor weakness; only one patient reported bowel and bladder dysfunction. All patients experienced transient neurological decline in the immediate postoperative period. Five recovered to independent ambulation at long-term follow-up, including one recovering to full strength. One patient required a repeat resection after four years due to tumor progression and functional decline. Tumor progression was not recorded in the other patients. CONCLUSIONS: Subtotal resection is a safe and effective treatment. Detethering of the spinal cord, resection of exophytic components, and tumor debulking can improve symptoms and prevent further deterioration in most cases. The resection can be assisted using a laser to vaporize the fatty tissue of the lipoma without physical manipulation of the spinal cord.

Comparison of accuracy, revision, and perioperative outcomes in robot-assisted spine surgeries: systematic review and meta-analysis.

OBJECTIVE: Pedicle screw placement guidance is critical in spinal fusions, and spinal surgery robots aim to improve accuracy and reduce complications. Current literature has yet to compare the relative merits of available robotic systems. In this review, the authors aimed to 1) assess the current state of spinal robotics literature; 2) conduct a meta-analysis of robotic performance based on accuracy, speed, and safety; and 3) offer recommendations for robotic system selection. METHODS: Following PRISMA guidelines, the authors conducted a systematic literature review across PubMed, Embase, Cochrane Library, Web of Science, and Scopus as of April 28, 2022, for studies on approved robots for placing lumbar pedicle screws. Three reviewers screened and extracted data relating to the study characteristics, accuracy rate, intraoperative revisions, and reoperations. Secondary performance metrics included operative time, blood loss, and radiation exposure. The authors statistically compared the performance of the robots using a random-effects model to account for variation within and between the studies. Each robot was also compared with performance benchmarks of traditional techniques including freehand, fluoroscopic, and CT-navigated insertion. Finally, we performed a Duval and Tweedie trim-and-fill test to assess for the presence of publication bias. RESULTS: The authors identified 46 studies, describing 4670 patients and 25,054 screws, that evaluated 4 different robotic systems: Mazor X, ROSA, ExcelsiusGPS, and Cirq. The weighted accuracy rates of Gertzbein-Robbins classification grade A or B screws were as follows: ExcelsiusGPS, 98.0%; ROSA, 98.0%; Mazor, 98.2%; and Cirq, 94.2%. No robot was significantly more accurate than the others. However, the accuracy of the ExcelsiusGPS was significantly higher than that of traditional methods, and the accuracies of the Mazor and ROSA were significantly higher than that of fluoroscopy. The intraoperative revision rates were Cirq, 0.55%; ROSA, 0.91%; Mazor, 0.98%; and ExcelsiusGPS, 1.08%. The reoperation rates were Cirq, 0.28%; ExcelsiusGPS, 0.32%; and Mazor, 0.76% (no reoperations were reported for ROSA). Operative times were similar for all robots. Both the ExcelsiusGPS and Mazor were associated with significantly less blood loss than the ROSA. The Cirq had the lowest radiation exposure. Robots tended to be more accurate and generally their use was associated with fewer reoperations and less blood loss than freehand, fluoroscopic, or CT-navigated techniques. CONCLUSIONS: Robotic platforms perform comparably based on key metrics, with high accuracy rates and low intraoperative revision and reoperation rates. The spinal robotics publication rate will continue to accelerate, and choosing a robot will depend on the context of the practice.

Exploring disparities in surgical recommendations for patients with primary intramedullary spinal cord tumors: an analysis of the Surveillance, Epidemiology, and End Results database from 2000 to 2019.

OBJECTIVE: Factors that may drive recommendations for operative intervention for patients with intramedullary spinal cord tumors (ISCTs) have yet to be extensively studied. The authors investigated racial and socioeconomic disparities in the management of patients with primary spinal cord ependymomas and nonependymal gliomas, with the aim of determining the associations between socioeconomic patient characteristics, survival, and recommendations for the resection of primary ISCTs. METHODS: The Surveillance, Epidemiology, and End Results registry was queried to identify all patients > 18 years of age with ISCTs diagnosed between 2000 and 2019. Univariable and multivariable logistic regression analyses were used to calculate odds ratios for variables associated with receiving a surgical recommendation. Log-rank tests and multivariable Cox proportional hazards models were used to investigate overall survival (OS) and disease-specific survival (DSS). RESULTS: The authors identified 2325 patients (mean age 49 [SD 16] years; 48.8% female; 67.4% non-Hispanic White, 7.8% non-Hispanic Black, 16.2% Hispanic, 6.5% Asian/Pacific Islander, 0.6% Native American; 56.7% married; 64.4% with household income < $75,000; 73.8% with spinal ependymoma; and 26.2% with nonependymal spinal glioma). Eighty-seven percent of patients received a surgical recommendation. In multivariable models, marriage was associated with higher odds of receiving a surgical recommendation for ependymomas (OR 1.80, p = 0.005). In multivariable models for nonependymal spinal gliomas, older age (OR 0.98, p = 0.001) and increased number of tumors (OR 0.62, p = 0.015) were associated with decreased odds of receiving surgical recommendations. Among ependymomas, marriage (HR 0.59, p = 0.001), younger age (HR 0.93, p < 0.001), female sex (HR 0.43, p = 0.006), and decreased number of tumors (HR 0.56, p < 0.001) were associated with improved OS. Among nonependymal spinal gliomas, median household income ≥ $75,000 (HR 0.69, p = 0.020) and younger age (HR 0.98, p < 0.001) were associated with improved DSS, while Black race (HR 4.65, p = 0.027) and older age (HR 1.05, p < 0.001) were associated with worse OS. CONCLUSIONS: In patients with spinal ependymomas and nonependymal spinal gliomas, recommendations for surgery appear to be unaffected by patient sex, race, or income. Survival disparities appear to exist among unmarried, male, Black, and lower-income cohorts. Continued initiatives to identify drivers of disparities while improving health equity in this patient population are needed.

Initial institutional experience using a robotic arm-enabled 4K 3D exoscope in neurosurgical operations.

The extracorporeal telescope (exoscope) presents a novel digital camera system as a versatile alternative to traditional optical microscopy for microsurgery and minimally invasive neurosurgical operations. Recent innovations in exoscope technology offer 4K-definition multiscreen outputs, pneumatic robot arms, 3-dimensional depth perception, and greater illumination, focus, and magnification powers for enhanced intraoperative visualization. The authors present their initial institutional experience using a robotic arm-enabled 4K 3D exoscope in a variety of cranial and spinal neurosurgical operations, namely Chiari decompression, microvascular decompression for trigeminal neuralgia, anterior cervical discectomy, and lumbar decompressions. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23150.

Exoscope Use in Spine Surgery: A Systematic Review of Applications, Benefits, and Limitations.

BACKGROUND: Exoscopes were recently developed as an alternative to the operative microscope (OM) and endoscope for intraoperative visualization during neurosurgery. Prior reviews studying mixed cranial and spinal surgical cohorts reported advantages with exoscope use, including improved ergonomics and teaching. In recent years, there has been an increase in exoscope research, with no updated systematic review focused exclusively on the benefits and limitations of exoscope use in spine surgery. Thus, we sought to systematically synthesize the literature related to exoscope-assisted spine surgery. METHODS: A literature search was conducted using the PubMed, Embase, Scopus, Cochrane, and Web of Science databases to identify relevant studies reported between 2010 and September 2023. Data, such as the exoscope model used, procedure types performed, and user observations, were then collected. RESULTS: A total of 31 studies met our inclusion criteria, including 481 patients with spine pathologies who underwent a surgical procedure using 1 of 9 exoscope models. The lumbar region was the most frequently operated area (n = 234; 48.6%), and discectomies comprised the most overall procedures (n = 273; 56.8%). All patients benefited clinically. The reported advantages of exoscopes compared with OMs or endoscopes were improved focal distance, surgeon posture, trainee education, compactness, and assistant participation. Other aspects such as stereopsis, illumination, and cost had various observations. CONCLUSIONS: Exoscopes have advantages compared with OMs or endoscopes during spine surgery. The user learning curve is minimal, and no negative patient outcomes have been reported. However, some aspects of exoscope use necessitate longer term prospective research before exoscopes can be considered a standard tool in the armamentarium of intraoperative visualization strategies.

Survival Factors in 1580 Adults with Spinal Ependymoma: Insights from a Multicenter Oncology Database.

BACKGROUND: Using a multi-institutional oncology database, we investigate the survival rates and the impacts of demographic, clinical, and management characteristics on overall survival among adult patients diagnosed with spinal ependymoma. METHODS: Utilizing the SEER registry, patients with histologically or radiologically confirmed ependymomas were included. Factors impacting overall survival were analyzed using Kaplan-Meier survival curves and log-rank statistical analyses. RESULTS: A total of 1,580 patients were included. Their mean ± standard deviation age was 46.68 ± 15.96 years, and 51.1% were women. Gross total resection (GTR) was achieved in 66.4% of patients. The 5- and 10-year survival rates were 96.7% and 95.4%, respectively. A multivariable backward Cox regression showed that age ≥65 years was a significant predictor for mortality (hazard ratio [HR]: 3.93; 95% confidence interval [CI]: 2.21-7.00; P < 0.001). Likewise, tumor grade 3 (HR: 6.36; 95% CI: 1.95-20.76; P = 0.002), tumor grade 4 (HR: 7.74; 95% CI: 3.97-15.11; P < 0.001), presence of extra-neural metastasis (HR: 13.81; 95% CI: 3.67-51.96; P < 0.001), and receiving radiotherapy (HR: 2.50; 95% CI: 1.50-4.19; P < 0.001) were significant risk factors for mortality, while GTR was significantly associated with improved overall survival compared with subtotal resection or nonsurgical management (HR: 0.42; 95% CI: 0.25-0.73; P = 0.002). There were no significant effects for gender, race, marital status, income, residential area, chemotherapy, tumor size, and the presence of other benign or malignant tumors on the survival hazards (P > 0.05 for each). CONCLUSION: Early diagnosis and surgical management of spinal ependymomas, such as GTR, were associated with remarkable survival benefits. Old age, high-grade spinal ependymoma, and extra-neural metastasis were associated with worse overall survival, whereas radiotherapy's role remains unclear.

Nerve-Targeted Surgical Treatments for Spasticity: A Narrative Review.

Spasticity is a potentially debilitating symptom of various acquired and congenital neurologic pathologies that, without adequate treatment, may lead to long-term disability, compromise functional independence, and negatively impact mental health. Several conservative as well as non-nerve targeted surgical strategies have been developed for the treatment of spasticity, but these may be associated with significant drawbacks, such as adverse side effects to medication, device dependence on intrathecal baclofen pumps, and inadequate relief with tendon-based procedures. In these circumstances, patients may benefit from nerve-targeted surgical interventions such as (i) selective dorsal rhizotomy, (ii) hyperselective neurectomy, and (iii) nerve transfer. When selecting the appropriate surgical approach, preoperative patient characteristics, as well as the risks and benefits of nerve-targeted surgical intervention, must be carefully evaluated. Here, we review the current evidence on the efficacy of these nerve-targeted surgical approaches for treating spasticity across various congenital and acquired neurologic pathologies.

External Validation of Predictive Models for Failed Medical Management of Spinal Epidural Abscess.

OBJECTIVE: There is limited consensus regarding management of spinal epidural abscesses (SEAs), particularly in patients without neurologic deficits. Several models have been created to predict failure of medical management in patients with SEA. We evaluate the external validity of 5 predictive models in an independent cohort of patients with SEA. METHODS: One hundred seventy-six patients with SEA between 2010 and 2019 at our institution were identified, and variables relevant to each predictive model were collected. Published prediction models were used to assign probability of medical management failure to each patient. Predicted probabilities of medical failure and actual patient outcomes were used to create receiver operating characteristic (ROC) curves, with the area under the receiver operating characteristic curve used to quantify a model's discriminative ability. Calibration curves were plotted using predicted probabilities and actual outcomes. The Spiegelhalter z-test was used to determine adequate model calibration. RESULTS: One model (Kim et al) demonstrated good discriminative ability and adequate model calibration in our cohort (ROC = 0.831, P value = 0.83). Parameters included in the model were age >65, diabetes, methicillin-resistant Staphylococcus aureus infection, and neurologic impairment. Four additional models did not perform well for discrimination or calibration metrics (Patel et al, ROC = 0.580, P ≤ 0.0001; Shah et al, ROC = 0.653, P ≤ 0.0001; Baum et al, ROC = 0.498, P ≤ 0.0001; Page et al, ROC = 0.534, P ≤ 0.0001). CONCLUSIONS: Only 1 published predictive model demonstrated acceptable discrimination and calibration in our cohort, suggesting limited generalizability of the evaluated models. Multi-institutional data may facilitate the development of widely applicable models to predict medical management failure in patients with SEA.