Prediction of Discharge Status and Readmissions after Resection of Intradural Spinal Tumors

Objective

Intradural spinal tumors are uncommon and while associations between clinical characteristics and surgical outcomes have been explored, there remains a paucity of literature unifying diverse predictors into an integrated risk model. To predict postresection outcomes for patients with spinal tumors.

Methods

IBM MarketScan Claims Database was queried for adult patients receiving surgery for intradural tumors between 2007 and 2016. Primary outcomes-of-interest were nonhome discharge and 90-day postdischarge readmissions. Secondary outcomes included hospitalization duration and postoperative complications. Risk modeling was developed using a regularized logistic regression framework (LASSO, least absolute shrinkage and selection operator) and validated in a withheld subset.

Results

A total of 5,060 adult patients were included. Most surgeries utilized a posterior approach (n=5,023, 99.3%) and tumors were most commonly found in the thoracic region (n=1,941, 38.4%), followed by the lumbar (n=1,781, 35.2%) and cervical (n=1,294, 25.6%) regions. Compared to models using only tumor-specific or patient-specific features, our integrated models demonstrated better discrimination (area under the curve [AUC] [nonhome discharge] = 0.786; AUC [90-day readmissions] = 0.693) and accuracy (Brier score [nonhome discharge] = 0.155; Brier score [90-day readmissions] = 0.093). Compared to those predicted to be lowest risk, patients predicted to be highest-risk for nonhome discharge required continued care 16.3 times more frequently (64.5% vs. 3.9%). Similarly, patients predicted to be at highest risk for postdischarge readmissions were readmitted 7.3 times as often as those predicted to be at lowest risk (32.6% vs. 4.4%).

Conclusion

Using a diverse set of clinical characteristics spanning tumor-, patient-, and hospitalization-derived data, we developed and validated risk models integrating diverse clinical data for predicting nonhome discharge and postdischarge readmissions.

Surgical Outcomes of Human Immunodeficiency Virus-positive Patients Undergoing Lumbar Degenerative Surgery

STUDY DESIGN

This was a retrospective cohort studying using a national administrative database.

OBJECTIVE

The objective of this study was to determine the postoperative complications and quality outcomes of the human immunodeficiency virus (HIV)-positive patients undergoing surgical management for lumbar degenerative disease (LDD).

METHODS

This study identified patients with who underwent surgery for LDD between 2007 and 2016. Patients were stratified based on whether they were HIV positive at the time of surgery. Multivariate regression was utilized to reduce the confounding of baseline covariates. Patients who underwent 3 or more levels of surgical correction were under the age of 18 years, or those with any prior history of trauma or tumor were excluded from this study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.

RESULTS

A total of 120,167 patients underwent primary lumbar degenerative surgery, of which 309 (0.26%) were HIV positive. In multivariate regression analysis, the HIV-positive cohort was more likely to be readmitted at 30 days [odds ratio (OR)=1.9, 95% confidence interval (CI): 1.2-2.8], 60 days (OR=1.7, 95% CI: 1.2-2.5), and 90 days (OR=1.5, 95% CI: 1.0-2.2). The HIV-positive cohort was also more likely to experience any postoperative complication (OR=1.7, 95% CI: 1.2-2.3). Of the major drivers identified, HIV-positive patients had significantly greater odds of cerebrovascular disease and postoperative neurological complications (OR=3.8, 95% CI: 1.8-6.9) and acute kidney injury (OR=3.4, 95% CI: 1.3-7.1). Costs of index hospitalization were not significantly different between the 2 cohorts ($30,056 vs. $29,720, P=0.6853). The total costs were also similar throughout the 2-year follow-up period.

CONCLUSION

Patients who are HIV positive at the time of LDD surgery are at a higher risk for postoperative central nervous system and renal complications and unplanned readmissions.

Defining and describing treatment heterogeneity in new-onset idiopathic lower back and extremity pain through reconstruction of longitudinal care sequences

BACKGROUND CONTEXT

Despite established guidelines, long-term management of surgically-treated low back pain (LBP) and lower extremity pain (LEP) remains heterogeneous. Understanding care heterogeneity could inform future approaches for standardization of practices.

PURPOSE

To describe treatment heterogeneity in surgically-managed LBP and LEP.

STUDY DESIGN/SETTING

Retrospective study of a nationwide commercial database spanning inpatient and outpatient encounters for enrollees of eligible employer-supplied healthcare plans (2007-2016).

PATIENT SAMPLE

A population-based sample of opioid-naïve adult patients with newly-diagnosed LBP or LEP were identified. Inclusion required at least 12-months of pre-diagnosis and post-diagnosis continuous follow-up.

EXPOSURE

Included treatments/evaluations include conservative management (chiropractic manipulative therapy, physical therapy, epidural steroid injections), imaging (x-ray, MRI, CT), pharmaceuticals (opioids, benzodiazepines), and spine surgery (decompression, fusion).

OUTCOME MEASURES

Primary outcomes-of-interest were 12-month net healthcare expenditures (inpatient and outpatient) and 12-month opioid usage.

METHODS

Analyses include interrogation of care sequence heterogeneity and temporal trends in sequence-initiating services. Comparisons were conducted in the framework of sequence-specific treatment sequences, which reflect the personalized order of healthcare services pursued by each patient. Outlier sequences characterized by high opioid use and costs were identified from frequently observed surgical treatment sequences using Mahalanobis distance.

RESULTS

A total of 2,496,908 opioid-naïve adult patients with newly-diagnosed LBP or LEP were included (29,519 surgical). In the matched setting, increased care sequence heterogeneity was observed in surgical patients (0.51 vs. 0.12 previously-unused interventions/studies pursued per month). Early opioid and MRI use has decreased between 2008 and 2015 but is matched by increases in early benzodiazepine and x-ray use. Outlier sequences, characterized by increased opioid use and costs, were found in 5.8% of surgical patients. Use of imaging prior to conservative management was common in patients pursuing outlier sequences compared to non-outlier sequences (96.5% vs. 63.8%, p<.001). Non-outlier sequences were more frequently characterized by early conservative interventions (31.9% vs. 7.4%, p<.001).

CONCLUSIONS

Surgically-managed LBP and LEP care sequences demonstrate high heterogeneity despite established practice guidelines. Outlier sequences associated with high opioid usage and costs can be identified and are characterized by increased early imaging and decreased early conservative management. Elements that may portend suboptimal longitudinal management could provide opportunities for standardization of patient care.

The impact of osteoporosis on adult deformity surgery outcomes in Medicare patients

OBJECTIVE

To identify the impact of osteoporosis (OS) on postoperative outcomes in Medicare patients undergoing ASD surgery.

BACKGROUND

Patients with OP and advanced age experience higher than average rates of ASD. However, poor bone density could undermine the durability of a deformity correction.

METHODS

We queried the MarketScan Medicare Supplemental database to identify patients Medicare patients who underwent ASD surgery from 2007 to 2016.

RESULTS

A total of 2564 patients met the inclusion criteria of this study, of whom n = 971 (61.0%) were diagnosed with osteoporosis. Patients with OP had a similar 90-day postoperative complication rates (OP: 54.6% vs. non-OP: 49.2%, p = 0.0076, not significant after multivariate regression correction). This was primarily driven by posthemorrhagic anemia (37.6% in OP, vs. 33.1% in non-OP). Rates of revision surgery were similar at 90 days (non-OP 15.0%, OP 16.8%), but by 2 years, OP patients had a significantly higher reoperation rate (30.4% vs. 22.9%, p < 0.0001). In multivariate regression analysis, OP increased odds for revision surgery at 1 year (OR 1.4) and 2 years (OR 1.5) following surgery (all p < 0.05). OP was also an independent predictor of readmission at all time points (90 days, OR 1.3, p < 0.005).

CONCLUSION

Medicare patients with OP had elevated rates of complications, reoperations, and outpatient costs after undergoing primary ASD surgery.

Predictive modeling of long-term opioid and benzodiazepine use after intradural tumor resection

BACKGROUND CONTEXT

Despite increased awareness of the ongoing opioid epidemic, opioid and benzodiazepine use remain high after spine surgery. In particular, long-term co-prescription of opioids and benzodiazepines have been linked to high risk of overdose-associated death. Tumor patients represent a unique subset of spine surgery patients and few studies have attempted to develop predictive models to anticipate long-term opioid and benzodiazepine use after spinal tumor resection.

METHODS

The IBM Watson Health MarketScan Database and Medicare Supplement were assessed to identify admissions for intradural tumor resection between 2007 and 2015. Adult patients were required to have at least 6 months of continuous preadmission baseline data and 12 months of continuous postdischarge follow-up. Primary outcomes were long-term opioid and benzodiazepine use, defined as at least 6 prescriptions within 12 months. Secondary outcomes were durations of opioid and benzodiazepine prescribing. Logistic regression models, with and without regularization, were trained on an 80% training sample and validated on the withheld 20%.

RESULTS

A total of 1,942 patients were identified. The majority of tumors were extramedullary (74.8%) and benign (62.5%). A minority of patients received arthrodesis (9.2%) and most patients were discharged to home (79.1%). Factors associated with postdischarge opioid use duration include tumor malignancy (vs benign, B=19.8 prescribed-days/year, 95% confidence interval [CI] 1.1-38.5) and intramedullary compartment (vs extramedullary, B=18.1 prescribed-days/year, 95% CI 3.3-32.9). Pre- and perioperative use of prescribed nonsteroidal anti-inflammatory drugs and gabapentin/pregabalin were associated with shorter and longer duration opioid use, respectively. History of opioid and history of benzodiazepine use were both associated with increased postdischarge opioid and benzodiazepine use. Intramedullary location was associated with longer duration postdischarge benzodiazepine use (B=10.3 prescribed-days/year, 95% CI 1.5-19.1). Among assessed models, elastic net regularization demonstrated best predictive performance in the withheld validation cohort when assessing both long-term opioid use (area under curve [AUC]=0.748) and long-term benzodiazepine use (AUC=0.704). Applying our model to the validation set, patients scored as low-risk demonstrated a 4.8% and 2.4% risk of long-term opioid and benzodiazepine use, respectively, compared to 35.2% and 11.1% of high-risk patients.

CONCLUSIONS

We developed and validated a parsimonious, predictive model to anticipate long-term opioid and benzodiazepine use early after intradural tumor resection, providing physicians opportunities to consider alternative pain management strategies.

A Novel Protocol for Reducing Intensive Care Utilization After Craniotomy

BACKGROUND

There is a growing body of evidence suggesting not all craniotomy patients require postoperative intensive care.

OBJECTIVE

To devise and implement a standardized protocol for craniotomy patients eligible to transition directly from the operating room to the ward-the Non-Intensive CarE (NICE) protocol.

METHODS

We preoperatively identified patients undergoing elective craniotomy for simple neurosurgical procedures with age <65 yr and American Society of Anesthesiologists (ASA) class of 1, 2 or 3. Postoperative eligibility was confirmed by the surgical and anesthesia teams. Upon arrival to the ward, patients were staffed with a neuroscience nurse for hourly neurological examinations for the first 8 h. Patient demographics, clinical characteristics, and outcomes were prospectively collected to evaluate the NICE protocol.

RESULTS

From February 2018 to 2019, 63 patients were included in the NICE protocol with a median age of 46 yr and 65% female predominance. Of the operations performed, 38.1% were microvascular decompressions, 31.7% were craniotomy for tumor, 15.9% were cavernous malformation resections, and 14.3% were Chiari decompressions. No patients required transfer to the intensive care unit (ICU). Median length of stay was 2 d. There was an 11.1% overall readmission rate within the median follow-up period of 48 d. Three patients (4.8%) required reoperation at time of readmission within the follow-up period (1 postoperative subdural hematoma, 2 cerebrospinal fluid leak repair). None of these complications could have been identified with a postoperative ICU stay.

CONCLUSION

In our pilot trial of the NICE protocol, no patients required postoperative transfer to the ICU.

Postoperative Complication Burden, Revision Risk, and Health Care Use in Obese Patients Undergoing Primary Adult Thoracolumbar Deformity Surgery

STUDY DESIGN

This is a retrospective cohort study using a nationally representative administrative database.

OBJECTIVE

To identify the impact of obesity on postoperative outcomes in patients undergoing thoracolumbar adult spinal deformity (ASD) surgery.

BACKGROUND

The obesity rate in the United States remains staggering, with approximately one-third of all Americans being overweight or obese. However, the impact of elevated body mass index on spine surgery outcomes remains unclear.

METHODS

We queried the MarketScan database to identify patients who were diagnosed with a spinal deformity and underwent ASD surgery from 2007 to 2016. Patients were then stratified by whether or not they were diagnosed as obese at index surgical admission. Propensity score matching (PSM) was then utilized to mitigate intergroup differences between obese and nonobese patients. Patients <18 years and those with any prior history of trauma or tumor were excluded from this study. Baseline demographics and comorbidities, postoperative complication rates, and short- and long-term reoperation rates were determined.

RESULTS

A total of 7423 patients met the inclusion criteria of this study, of whom 597 (8.0%) were obese. Initially, patients with obesity had a higher 90-day postoperative complication rate than nonobese patients (46.1% vs 40.8%, P < .05); however, this difference did not remain after PSM. Revision surgery rates after 2 years were similar across the 2 groups following primary surgery (obese, 21.4%, vs nonobese, 22.0%; P = .7588). Health care use occurred at a higher rate among obese patients through 2 years of long-term follow-up (obese, $152 930, vs nonobese, $140 550; P < .05).

CONCLUSION

Patients diagnosed with obesity who underwent ASD surgery did not demonstrate increased rates of complications, reoperations, or readmissions. However, overall health care use through 2 years of follow-up after index surgery was higher in the obesity cohort.

An Analysis of Public Interest in Elective Neurosurgical Procedures During the COVID-19 Pandemic Through Online Search Engine Trends

OBJECTIVE

In the wake of the COVID-19 pandemic, the Centers for Medicare & Medicaid Services (CMS) has recommended the temporary cessation of all elective surgeries. The effects on patients' interest of elective neurosurgical procedures are currently unexplored.

METHODS

Using Google Trends, search terms of 7 different neurosurgical procedure categories (trauma, spine, tumor, movement disorder, epilepsy, endovascular, and miscellaneous) were assessed in terms of relative search volume (RSV) between January 2015 and September 2020. Analyses of search terms were performed for over the short term (February 18, 2020, to April 18, 2020), intermediate term (January 1, 2020, to May 31, 2020), and long term (January 2015 to September 2020). State-level interest during phase I reopening (April 28, 2020, to May 31, 2020) was also evaluated.

RESULTS

In the short term, RSVs of 4 categories (epilepsy, movement disorder, spine, and tumor) were significantly lower in the post-CMS announcement period. In the intermediate term, RSVs of 5 categories (miscellaneous, epilepsy, movement disorder, spine, and tumor) were significantly lower in the post-CMS announcement period. In the long term, RSVs of nearly all categories (endovascular, epilepsy, miscellaneous, movement disorder, spine, and tumor) were significantly lower in the post-CMS announcement period. Only the movement disorder procedure category had significantly higher RSV in states that reopened early.

CONCLUSIONS

With the recommendation for cessation of elective surgeries, patient interests in overall elective neurosurgical procedures have dropped significantly. With gradual reopening, there has been a resurgence in some procedure types. Google Trends has proven to be a useful tracker of patient interest and may be used by neurosurgical departments to facilitate outreach strategies.

Timing of Adjuvant Radiation Therapy and Risk of Wound-Related Complications Among Patients With Spinal Metastatic Disease

STUDY DESIGN

This was an epidemiological study using national administrative data from the MarketScan database.

OBJECTIVE

To investigate the impact of early versus delayed adjuvant radiotherapy (RT) on wound healing following surgical resection for spinal metastatic disease.

METHODS

We queried the MarketScan database (2007-2016), identifying patients with a diagnosis of spinal metastasis who also underwent RT within 8 weeks of surgery. Patients were categorized into "Early RT" if they received RT within 4 weeks of surgery and as "Late RT" if they received RT between 4 and 8 weeks after surgery. Descriptive statistics and hypothesis testing were used to compare baseline characteristics and wound complication outcomes.

RESULTS

A total of 540 patients met the inclusion criteria: 307 (56.9%) received RT within 4 weeks (Early RT) and 233 (43.1%) received RT within 4 to 8 weeks (Late RT) of surgery. Mean days to RT for the Early RT cohort was 18.5 (SD, 6.9) and 39.7 (SD, 7.6) for the Late RT cohort. In a 90-day surveillance period, n = 9 (2.9%) of Early RT and n = 8 (3.4%) of Late RT patients developed wound complications (P = .574).

CONCLUSIONS

When comparing patients who received RT early versus delayed following surgery, there were no significant differences in the rates of wound complications. Further prospective studies should aim to identify optimal patient criteria for early postoperative RT for spinal metastases.

Outcomes After Cervical Disc Arthroplasty Versus Stand-Alone Anterior Cervical Discectomy and Fusion: A Meta-Analysis

STUDY DESIGN

Systemic review and meta-analysis.

OBJECTIVES

To review and compare surgical outcomes for patients undergoing stand-alone anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA) for the treatment of cervical spine disease.

METHODS

A systematic search was performed on PubMed, Medline, and the Cochrane Library. Comparative trials measuring outcomes of patients undergoing CDA and stand-alone ACDF for degenerative spine disease in the last 10 years were selected for inclusion. After data extraction and quality assessment, statistical analysis was performed with R software metafor package. The random-effects model was used if there was heterogeneity between studies; otherwise, the fixed-effects model was used.

RESULTS

In total, 12 studies including 859 patients were selected for inclusion in the meta-analysis. Patients undergoing stand-alone ACDF had a statistically significant increase in postoperative segmental angles (mean difference 0.85° [95% confidence interval = 0.35° to 1.35°], P = .0008). Patients undergoing CDA had a decreased rate of developing adjacent segmental degeneration (risk ratio = 0.56 [95% confidence interval = -0.06 to 1.18], P = .0745). Neck Disability Index, Japanese Orthopedic Association score, Visual Analogue Scale of the arm and neck, as well as postoperative cervical angles were similar between the 2 treatments.

CONCLUSIONS

When compared with CDA, stand-alone ACDF offers similar clinical outcomes for patients and leads to increased postoperative segmental angles. We encourage further blinded randomized trials to compare rates of adjacent segmental degeneration and other postoperative outcomes between these 2 treatments options.

Contemporaneous evaluation of patient experience, surgical strategy, and seizure outcomes in patients undergoing stereoelectroencephalography or subdural electrode monitoring

OBJECTIVE

Intracranial electrographic localization of the seizure onset zone (SOZ) can guide surgical approaches for medically refractory epilepsy patients, especially when the presurgical workup is discordant or functional cortical mapping is required. Minimally invasive stereotactic placement of depth electrodes, stereoelectroencephalography (SEEG), has garnered increasing use, but limited data exist to evaluate its postoperative outcomes in the context of the contemporaneous availability of both SEEG and subdural electrode (SDE) monitoring. We aimed to assess the patient experience, surgical intervention, and seizure outcomes associated with these two epileptic focus mapping techniques during a period of rapid adoption of neuromodulatory and ablative epilepsy treatments.

METHODS

We retrospectively reviewed 66 consecutive adult intracranial electrode monitoring cases at our institution between 2014 and 2017. Monitoring was performed with either SEEG (n = 47) or SDEs (n = 19).

RESULTS

Both groups had high rates of SOZ identification (SEEG 91.5%, SDE 88.2%, P = .69). The majority of patients achieved Engel class I (SEEG 29.3%, SDE 35.3%) or II outcomes (SEEG 31.7%, SDE 29.4%) after epilepsy surgery, with no significant difference between groups (P = .79). SEEG patients reported lower median pain scores (P = .03) and required less narcotic pain medication (median = 94.5 vs 594.6 milligram morphine equivalents, P = .0003). Both groups had low rates of symptomatic hemorrhage (SEEG 0%, SDE 5.3%, P = .11). On multivariate logistic regression, undergoing resection or ablation (vs responsive neurostimulation/vagus nerve stimulation) was the only significant independent predictor of a favorable outcome (adjusted odds ratio = 25.4, 95% confidence interval = 3.48-185.7, P = .001).

SIGNIFICANCE

Although both SEEG and SDE monitoring result in favorable seizure control, SEEG has the advantage of superior pain control, decreased narcotic usage, and lack of routine need for intensive care unit stay. Despite a heterogenous collection of epileptic semiologies, seizure outcome was associated with the therapeutic surgical modality and not the intracranial monitoring technique. The potential for an improved postoperative experience makes SEEG a promising method for intracranial electrode monitoring.

Resection of Olfactory Groove Meningiomas Through Unilateral vs. Bilateral Approaches: A Systematic Review and Meta-Analysis

Introduction: Consensus is limited regarding optimal transcranial approaches (TCAs) for the surgical resection of olfactory groove meningiomas (OGMs). This systematic review and meta-analysis aims to examine operative and peri-operative outcomes of unilateral compared to bilateral TCAs for OGMs. Methods: Electronic databases were searched from inception until December 2019 for studies delineating TCAs for OGM patients. Patient demographics, pre-operative symptoms, surgical outcomes, and complications were evaluated and analyzed with a meta-analysis of proportions. Results: A total of 27 observational case series comparing 554 unilateral vs. 451 bilateral TCA patients were eligible for review. The weighted pooled incidence of gross total resection is 94.6% (95% CI, 90.7-97.5%; I ² = 59.0%; p = 0.001) for unilateral and 90.9% (95% CI, 85.6-95.4%; I ² = 58.1%; p = 0.003) for bilateral cohorts. Similarly, the incidence of OGM recurrence is 2.6% (95% CI, 0.4-6.0%; I ² = 53.1%; p = 0.012) and 4.7% (95% CI, 1.4-9.2%; I ² = 55.3%; p = 0.006), respectively. Differences in oncologic outcomes were not found to be statistically significant (p = 0.21 and 0.35, respectively). Statistically significant differences in complication rates in bilateral vs. unilateral TCA cohorts include meningitis (1.0 vs. 0.0%; p = 0.022) and mortality (3.2 vs. 0.2%; p = 0.007). Conclusions: While both cohorts have similar oncologic outcomes, bilateral TCA patients exhibit higher post-operative complication rates. This may be explained by underlying tumor characteristics necessitating more radical resection but may also indicate increased morbidity with bilateral approaches. However, evidence from more controlled, comparative studies is warranted to further support these findings.

Staged Surgical Resection of Brain Arteriovenous Malformations

BACKGROUND

Staged treatment of brain arteriovenous malformations (AVMs) is sometimes necessary to minimize risks associated with sudden changes in cerebral hemodynamics. With the increasing availability and optimization of endovascular techniques, multiple surgical resections are rarely necessary, although, due to specific anatomic circumstances, some AVMs still require staged surgery. Here, we describe the largest reported series of staged surgical resections of brain AVMs.

METHODS

This is a retrospective review of surgically resected AVMs at a single institution from 1998-2018. Patients who underwent ≥2 resections within 1 year were reviewed. Only those in whom initial resection was terminated with intention for further resection were included in analysis.

RESULTS

Twenty patients underwent deliberately staged resection from 1998-2018. Average age at treatment was 36.2 years (SD 16.5 years). Eleven patients (55%) were female, and 12 (60%) had left-sided AVMs. Median Spetzler-Martin grade was 4 (interquartile range [IQR]: 3-4). Average AVM nidus diameter was 5.0 cm (SD 1.7 cm). Seven patients (35%) presented with AVM rupture, and 12 (60%) presented with focal neurologic deficits without hemorrhage. Seventeen patients (85%) underwent preoperative embolization, median number of embolizations was 3 (IQR: 2-4). Three patients (15%) underwent preoperative radiosurgery. Median number of days between surgeries was 28 (IQR: 8-41 days). Perioperative course was complicated by hemorrhage in 3 patients (15%); 1 required decompressive hemicraniectomy prior to the second stage of surgery. Good functional outcome (defined as modified Rankin Scale score ≤2) was achieved in 14 patients (70%).

CONCLUSIONS

Staged surgical resection of large and complex AVMs can be performed with good outcomes in carefully selected patients.

Frameless Robot-Assisted Deep Brain Stimulation Surgery: An Initial Experience

BACKGROUND

Modern robotic-assist surgical systems have revolutionized stereotaxy for a variety of procedures by increasing operative efficiency while preserving and even improving accuracy and safety. However, experience with robotic systems in deep brain stimulation (DBS) surgery is scarce.

OBJECTIVE

To present an initial series of DBS surgery performed utilizing a frameless robotic solution for image-guided stereotaxy, and report on operative efficiency, stereotactic accuracy, and complications.

METHODS

This study included the initial 20 consecutive patients undergoing bilateral robot-assisted DBS. The prior 20 nonrobotic, frameless cohort of DBS cases was sampled as a baseline historic control. For both cohorts, patient demographic and clinical data were collected including postoperative complications. Intraoperative duration and number of Microelectrode recording (MER) and final lead passes were recorded. For the robot-assisted cohort, 2D radial errors were calculated.

RESULTS

Mean case times (total operating room, anesthesia, and operative times) were all significantly decreased in the robot-assisted cohort (all P-values < .02) compared to frameless DBS. When looking at trends in case times, operative efficiency improved over time in the robot-assisted cohort across all time assessment points. Mean radial error in the robot-assisted cohort was 1.40 ± 0.11 mm, and mean depth error was 1.05 ± 0.18 mm. There was a significant decrease in the average number of MER passes in the robot-assisted cohort (1.05) compared to the nonrobotic cohort (1.45, P < .001).

CONCLUSION

This is the first report of application of frameless robotic-assistance with the Mazor Renaissance platform (Mazor Robotics Ltd, Caesarea, Israel) for DBS surgery, and our findings reveal that an initial experience is safe and can have a positive impact on operative efficiency, accuracy, and safety.

Predictors of 2-year reoperation in Medicare patients undergoing primary thoracolumbar deformity surgery

OBJECTIVE

This was a retrospective cohort study in which the authors used a nationally representative administrative database. Their goal was to identify the risk factors for reoperation in Medicare patients undergoing primary thoracolumbar adult spinal deformity (ASD) surgery. Previous literature reports estimate that 20% of patients undergoing thoracolumbar ASD correction undergo revision surgery within 2 years. Most published data discuss risk factors for revision surgery in the general population, but these have not been explored specifically in the Medicare population.

METHODS

Using the MarketScan Medicare Supplemental database, the authors identified patients who were diagnosed with a spinal deformity and underwent ASD surgery between 2007 and 2015. The interactions of patient demographics, surgical factors, and medical factors with revision surgery were investigated during the 2 years following primary ASD surgery. The authors excluded patients without Medicare insurance and those with any prior history of trauma or tumor.

RESULTS

Included in the data set were 2564 patients enrolled in Medicare who underwent ASD surgery between 2007 and 2015. The mean age at diagnosis with spinal deformity was 71.5 years. A majority of patients (68.5%) were female. Within 2 years of follow-up, 661 (25.8%) patients underwent reoperation. Preoperative osteoporosis (OR 1.58, p < 0.0001), congestive heart failure (OR 1.35, p = 0.0161), and paraplegia (OR 2.41, p < 0.0001) independently increased odds of revision surgery. The use of intraoperative bone morphogenetic protein was protective against reoperation (OR 0.71, p = 0.0371). Among 90-day postoperative complications, a wound complication was the strongest predictor of undergoing repeat surgery (OR 2.85, p = 0.0061). The development of a pulmonary embolism also increased the odds of repeat surgery (OR 1.84, p = 0.0435).

CONCLUSIONS

Approximately one-quarter of Medicare patients with ASD who underwent surgery required an additional spinal surgery within 2 years. Baseline comorbidities such as osteoporosis, congestive heart failure, and paraplegia, as well as short-term complications such as pulmonary embolism and wound complications significantly increased the odds of repeat surgery.

Single- versus dual-attending strategy for spinal deformity surgery: 2-year experience and systematic review of the literature

OBJECTIVE

Adult spinal deformity (ASD) surgery is complex and associated with high morbidity and complication rates. There is growing evidence in the literature for the beneficial effects of an approach to surgery in which two attending physicians rather than a single attending physician perform surgery for and oversee the surgical care of a single patient in a dual-attending care model. The authors developed a dual-attending care collaboration in August 2017 in which a neurosurgeon and an orthopedic surgeon mutually operated on patients with ASD.

METHODS

The authors recorded data for 2 years of experience with ASD patients operated on by dual attending surgeons. Analyses included estimated blood loss (EBL), transfusions, length of stay (LOS), discharge disposition, complication rates, emergency room visits and readmissions, subjective health status improvement, and disability (Oswestry Disability Index [ODI] score) and pain (visual analog scale [VAS] score) at last follow-up. In addition, the pertinent literature for dual-attending spinal deformity correction was systematically reviewed.

RESULTS

The study group comprised 19 of 254 (7.5%) consecutively operated patients who underwent thoracolumbar fusion during the period from January 2017 to June 2019 (68.4% female; mean patient age 65.1 years, ODI score 44.5, VAS pain score 6.8). The study patients were matched by age, sex, anesthesia risk, BMI, smoking status, ODI score, VAS pain score, prior spine surgeries, and basic operative characteristics (type of interbody implants, instrumented segments, pelvic fixation) to 19 control patients (all p > 0.05). There was a trend toward less EBL (mean 763 vs 1524 ml, p = 0.059), fewer intraoperative red blood cell transfusions (mean 0.5 vs 2.3, p = 0.079), and fewer 90-day readmissions (0% vs 15.8%, p = 0.071) in the dual-attending group. LOS and discharge disposition were similar, as were the rates of any < 30-day postsurgery complications, < 90-day postsurgery emergency room visits, and reoperations, and ODI and VAS pain scores at last follow-up (all p > 0.05). At last follow-up, 94.7% vs 68.4% of patients in the dual- versus single-attending group stated their health status had improved (p = 0.036). In the authors' literature search of prior articles on spinal deformity correction, 5 of 8 (62.5%) articles reported lower EBL and 6 of 8 (75%) articles reported significantly lower operation duration in dual-attending cases. The literature contained differing results with regard to complication- or reoperation-sparing effects associated with dual-attending cases. Similar clinical outcomes of dual- versus single-attending cases were reported.

CONCLUSIONS

Establishing a dual-attending care management platform for ASD correction was feasible at the authors' institution. Results of the use of a dual-attending strategy at the authors' institution were favorable. Positive safety and outcome profiles were found in articles on this topic identified by a systematic literature review.

Intraoperative Evaluation of Essential Vocal Tremor in Deep Brain Stimulation Surgery

Purpose Essential vocal tremor (EVT) is a prevalent and difficult-to-manage voice disorder. There is evidence that deep brain stimulation (DBS) of the ventral intermediate nucleus (Vim) of the thalamus may be beneficial for treating EVT. The objective of this preliminary investigation was to conduct intraoperative voice assessments during Vim-DBS implantation in order to evaluate immediate voice outcomes in medication-refractory essential tremor patients with co-occurring EVT. Method Seven adult subjects diagnosed with EVT undergoing Vim-DBS surgery participated in this investigation. Voice samples of sustained vowels were collected by a speech-language pathologist preoperatively and intraoperatively, immediately following Vim-DBS electrode placement. Voice evaluation included objective acoustic assessment of the rate and extent of EVT fundamental frequency and intensity modulation and subjective perceptual ratings of EVT severity. Results The rate of intensity modulation, extent of fundamental frequency modulation, and perceptual rating of EVT severity were significantly reduced intraoperatively as compared to preoperatively. Moderate, positive correlations were appreciated between a subset of acoustic measures and perceptual severity ratings. Conclusions The results of this study demonstrate a speech-language pathologist can conduct intra-operative evaluation of EVT during DBS surgery. Using a noninvasive, simple acoustic recording method, we were able to supplement perceptual subjective observation with objective assessment and demonstrate immediate, intraoperative improvements in EVT. The findings of this analysis inform the added value of intraoperative voice evaluation in Vim-DBS patients and contribute to the growing body of literature seeking to evaluate the efficacy of DBS as a treatment for EVT.

Conventional versus stereotactic image guided pedicle screw placement during spinal deformity correction: a retrospective propensity score-matched study of a national longitudinal database

PURPOSE/AIM

To compare complications, readmissions, revisions, and payments between navigated and conventional pedicle screw fixation for treatment of spine deformity.

METHODS

The Thomson Reuters MarketScan national longitudinal database was used to identify patients undergoing osteotomy, posterior instrumentation, and fusion for treatment of spinal deformity with or without image-guided navigation between 2007-2016. Conventional and navigated groups were propensity-matched (1:1) to normalize differences between demographics, comorbidities, and surgical characteristics. Clinical outcomes and charges were compared between matched groups using bivariate analyses.

RESULTS

A total of 4,604 patients were identified as having undergone deformity correction, of which 286 (6.2%) were navigated. Propensity-matching resulted in a total of 572 well-matched patients for subsequent analyses, of which half were navigated. Rate of mechanical instrumentation-related complications was found to be significantly lower for navigated procedures (p = 0.0371). Navigation was also associated with lower rates of 90-day unplanned readmissions (p = 0.0295), as well as 30- and 90-day postoperative revisions (30-day: p = 0.0304, 90-day: p = 0.0059). Hospital, physician, and total payments favored the conventional group for initial admission (p = 0.0481, 0.0001, 0.0019, respectively); however, when taking into account costs of readmissions, hospital payments became insignificantly different between the two groups.

CONCLUSIONS

Procedures involving image-guided navigation resulted in decreased instrumentation-related complications, unplanned readmissions, and postoperative revisions, highlighting its potential utility for the treatment of spine deformity. Future advances in navigation technologies and methodologies can continue to improve clinical outcomes, decrease costs, and facilitate widespread adoption of navigation for deformity correction.

Boda Bodas and Road Traffic Injuries in Uganda: An Overview of Traffic Safety Trends from 2009 to 2017

INTRODUCTION

Road traffic injuries (RTIs) are an important contributor to the morbidity and mortality of developing countries. In Uganda, motorcycle taxis, known as boda bodas, are responsible for a growing proportion of RTIs. This study seeks to evaluate and comment on traffic safety trends from the past decade.

METHODS

Traffic reports from the Ugandan police force (2009 to 2017) were analyzed for RTI characteristics. Furthermore, one month of casualty ward data in 2015 and 2018 was collected from the Mulago National Referral Hospital and reviewed for casualty demographics and trauma type.

RESULTS

RTI motorcycle contribution rose steadily from 2009 to 2017 (24.5% to 33.9%). While the total number of crashes dropped from 22,461 to 13,244 between 2010 and 2017, the proportion of fatal RTIs increased from 14.7% to 22.2%. In the casualty ward, RTIs accounted for a greater proportion of patients and traumas in 2018 compared to 2015 (10%/41% and 36%/64%, respectively).

CONCLUSIONS

Although RTIs have seen a gross reduction in Uganda, they have become more deadly, with greater motorcycle involvement. Hospital data demonstrate a rising need for trauma and neurosurgical care to manage greater RTI patient burden. Combining RTI prevention and care pathway improvements may mitigate current RTI trends.

Objective activity tracking in spine surgery: a prospective feasibility study with a low-cost consumer grade wearable accelerometer

Patient-reported outcome measures (PROMs) are commonly used to estimate disability of patients with spinal degenerative disease. Emerging technological advances present an opportunity to provide objective measurements of activity. In a prospective, observational study we utilized a low-cost consumer grade wearable accelerometer (LCA) to determine patient activity (steps per day) preoperatively (baseline) and up to one year (Y1) after cervical and lumbar spine surgery. We studied 30 patients (46.7% male; mean age 57 years; 70% Caucasian) with a baseline activity level of 5624 steps per day. The activity level decreased by 71% in the 1^st postoperative week (p < 0.001) and remained 37% lower in the 2^nd (p < 0.001) and 23% lower in the 4^th week (p = 0.015). At no time point until Y1 did patients increase their activity level, compared to baseline. Activity was greater in patients with cervical, as compared to patients with lumbar spine disease. Age, sex, ethnic group, anesthesia risk score and fusion were variables associated with activity. There was no correlation between activity and PROMs, but a strong correlation with depression. Determining activity using LCAs provides real-time and longitudinal information about patient mobility and return of function. Recovery took place over the first eight postoperative weeks, with subtle improvement afterwards.

Postoperative outcomes following pediatric intracranial electrode monitoring: A case for stereoelectroencephalography (SEEG)

BACKGROUND

For patients with medically refractory epilepsy, intracranial electrode monitoring can help identify epileptogenic foci. Despite the increasing utilization of stereoelectroencephalography (SEEG), the relative risks or benefits associated with the technique when compared with the traditional subdural electrode monitoring (SDE) remain unclear, especially in the pediatric population. Our aim was to compare the outcomes of pediatric patients who received intracranial monitoring with SEEG or SDE (grids and strips).

METHODS

We retrospectively studied 38 consecutive pediatric intracranial electrode monitoring cases performed at our institution from 2014 to 2017. Medical/surgical history and operative/postoperative records were reviewed. We also compared direct inpatient hospital costs associated with the two procedures.

RESULTS

Stereoelectroencephalography and SDE cohorts both showed high likelihood of identifying epileptogenic zones (SEEG: 90.9%, SDE: 87.5%). Compared with SDE, SEEG patients had a significantly shorter operative time (118.7 versus 233.4 min, P < .001) and length of stay (6.2 versus 12.3 days, P < .001), including days spent in the intensive care unit (ICU; 1.4 versus 5.4 days, P < .001). Stereoelectroencephalography patients tended to report lower pain scores and used significantly less narcotic pain medications (54.2 versus 197.3 mg morphine equivalents, P = .005). No complications were observed. Stereoelectroencephalography and SDE cohorts had comparable inpatient hospital costs (P = .47).

CONCLUSION

In comparison with subdural electrode placement, SEEG results in a similarly favorable clinical outcome, but with reduced operative time, decreased narcotic usage, and superior pain control without requiring significantly higher costs. The potential for an improved postoperative intracranial electrode monitoring experience makes SEEG especially suitable for pediatric patients.

Utilization of Novel High-Resolution, MRI-Based Vascular Imaging Modality for Preoperative Stereoelectroencephalography Planning in Children: A Technical Note

INTRODUCTION

Stereoelectroencephalography (SEEG) is a powerful intracranial diagnostic tool that requires accurate imaging for proper electrode trajectory planning to ensure efficacy and maximize patient safety. Computed tomography (CT) angiography and digital subtraction angiography are commonly used, but recent developments in magnetic resonance angiography allow for high-resolution vascular visualization without added risks of radiation. We report on the accuracy of electrode placement under robotic assistance planning utilizing a novel high-resolution magnetic resonance imaging (MRI)-based imaging modality.

METHODS

Sixteen pediatric patients between February 2014 and October 2017 underwent SEEG exploration for epileptogenic zone localization. A gadolinium-enhanced 3D T1-weighted spoiled gradient recalled echo sequence with minimum echo time and repetition time was applied for background parenchymal suppression and vascular enhancement. Electrode placement accuracy was determined by analyzing postoperative CT scans laid over preoperative virtual electrode trajectory paths. Entry point, target point, and closest vessel intersection were measured.

RESULTS

For any intersection along the trajectory path, 57 intersected vessels were measured. The mean diameter of an intersected vessel was 1.0343 ± 0.1721 mm, and 21.05% of intersections involved superficial vessels. There were 157 overall intersection + near-miss events. The mean diameter for an involved vessel was 1.0236 ± 0.0928 mm, and superficial vessels were involved in 20.13%. Looking only at final electrode target, 3 intersection events were observed. The mean diameter of an intersected vessel was 1.0125 ± 0.2227 mm. For intersection + near-miss events, 24 were measured. An involved vessel's mean diameter was 1.1028 ± 0.2634 mm. For non-entry point intersections, 45 intersected vessels were measured. The mean diameter for intersected vessels was 0.9526 ± 0.0689 mm. For non-entry point intersections + near misses, 126 events were observed. The mean diameter for involved vessels was 0.9826 ± 0.1008 mm.

CONCLUSION

We believe this novel sequence allows better identification of superficial and deeper subcortical vessels compared to conventional T1-weighted gadolinium-enhanced MRI.

Functional Mapping for Glioma Surgery: A Propensity-Matched Analysis of Outcomes and Cost

OBJECTIVE

To compare clinical outcomes and payments between glioma resections with and without functional mapping.

METHODS

The Thomas Reuters MarketScan national longitudinal database was used to identify patients undergoing resection of supratentorial primary malignant glioma with or without functional mapping between 2007 and 2016. Patients were stratified into mapped and unmapped (conventional) groups and subsequently propensity-matched based on demographics, clinical comorbidities, and surgical characteristics (i.e., use of stereotactic navigation, microscope, and intratumoral chemotherapy). Outcomes and charges were compared between matched groups using bivariate analyses.

RESULTS

A total of 14,037 patients were identified, of whom 796 (6.0%) received functional mapping. Propensity matching (1:1) resulted in 796 mapped patients and 796 propensity-matched controls. Thirty-day postoperative rates of new-onset seizures, cerebral edema, hemorrhage, and neurologic deficits were significantly lower for the functional mapping group (all P < 0.05). Functional mapping was also associated with shorter hospital length of stay (P = 0.0144), lower 30-day rates of emergency department visits (P = 0.0001), and fewer reoperations (P = 0.0068). Total costs of initial admission were not significantly different between groups.

CONCLUSIONS

Intraoperative functional mapping during glioma resection was associated with decreased complications, reoperations, emergency department visits, and shorter lengths of stay. Furthermore, total charges of mapped resections were not significantly different from those of conventional resections. These findings support the usefulness of functional mapping for resection of supratentorial primary malignant gliomas.

Patterns of Opioid and Benzodiazepine Use in Opioid-Naïve Patients with Newly Diagnosed Low Back and Lower Extremity Pain

BACKGROUND

The morbidity and mortality associated with opioid and benzodiazepine co-prescription is a pressing national concern. Little is known about patterns of opioid and benzodiazepine use in patients with acute low back pain or lower extremity pain.

OBJECTIVE

To characterize patterns of opioid and benzodiazepine prescribing among opioid-naïve, newly diagnosed low back pain (LBP) or lower extremity pain (LEP) patients and to investigate the relationship between benzodiazepine prescribing and long-term opioid use.

DESIGN/SETTING

We performed a retrospective analysis of a commercial database containing claims for more than 75 million enrollees in the USA.

PARTICIPANTS

Participants were adult patients newly diagnosed with LBP or LEP between 2008 and 2015 who did not have a red flag diagnosis, had not received an opioid prescription in the 6 months prior to diagnosis, and had 12 months of continuous enrollment after diagnosis.

MAIN OUTCOMES AND MEASURES

Among patients receiving at least one opioid prescription within 12 months of diagnosis, we defined discrete patterns of benzodiazepine prescribing-continued use, new use, stopped use, and never use. We tested the association of these prescription patterns with long-term opioid use, defined as six or more fills within 12 months.

RESULTS

We identified 2,497,653 opioid-naïve patients with newly diagnosed LBP or LEP. Between 2008 and 2015, 31.9% and 11.5% of these patients received opioid and benzodiazepine prescriptions, respectively, within 12 months of diagnosis. Rates of opioid prescription decreased from 34.8% in 2008 to 27.0% in 2015 (P < 0.001); however, prescribing of benzodiazepines only decreased from 11.6% in 2008 to 10.8% in 2015. Patients with continued or new benzodiazepine use consistently used more opioids than patients who never used or stopped using benzodiazepines during the study period (one-way ANOVA, P < 0.001). For patients with continued and new benzodiazepine use, the odds ratio of long-term opioid use compared with those never prescribed a benzodiazepine was 2.99 (95% CI, 2.89-3.08) and 2.68 (95% CI, 2.62-2.75), respectively.

LIMITATIONS

This study used administrative claims analyses, which rely on accuracy and completeness of diagnostic, procedural, and prescription codes.

CONCLUSION

Overall opioid prescribing for low back pain or lower extremity pain decreased substantially during the study period, indicating a shift in management within the medical community. Rates of benzodiazepine prescribing, however, remained at approximately 11%. Concurrent prescriptions of benzodiazepines and opioids after LBP or LEP diagnosis were associated with increased risk of long-term opioid use.

Robot-assisted versus manual navigated stereoelectroencephalography in adult medically-refractory epilepsy patients

OBJECTIVE

Stereoelectroencephalography (SEEG) has experienced a recent growth in adoption for epileptogenic zone (EZ) localization. Advances in robotics have the potential to improve the efficiency and safety of this intracranial seizure monitoring method. We present our institutional experience employing robot-assisted SEEG and compare its operative efficiency, seizure reduction outcomes, and direct hospital costs with SEEG performed without robotic assistance using navigated stereotaxy.

METHODS

We retrospectively identified 50 consecutive adult SEEG cases at our institution in this IRB-approved study, of which 25 were navigated with image guidance (hereafter referred to as "navigated") (02/2014-10/2016) and 25 were robot-assisted (09/2016-12/2017). A thorough review of medical/surgical history and operative records with imaging and trajectory plans was done for each patient. Direct inpatient costs related to each technique were compared.

RESULTS

Most common seizure etiologies for patients undergoing navigated and robot-assisted SEEG included non-lesional and benign temporal lesions. Despite having a higher mean number of leads-per-patient (10.2 ± 3.5 versus 7.2 ± 2.6, P = 0.002), robot-assisted cases had a significantly shorter mean operative time than navigated cases (125.5±48.5 versus 173.4±84.3 min, P = 0.02). Comparison of robot-assisted cases over the study interval revealed no significant difference in mean operative time (136.4±51.4 min for the first ten cases versus 109.9±75.8 min for the last ten cases, P = 0.25) and estimated operative time-per-lead (13.4±6.0 min for the first ten cases versus 12.9±7.7 min for the last ten cases, P = 0.86). The mean depth, radial, target, and entry point errors for robot-assisted cases were 2.12±1.89, 1.66±1.58, 3.05±2.02 mm, and 1.39 ± 0.75 mm, respectively. The two techniques resulted in equivalent EZ localization rate (navigated 88 %, robot-assisted 96 %, P = 0.30). Common types of epilepsy surgery performed consisted of implantation of responsive neurostimulation (RNS) device (56 %), resection (19.1 %), and laser ablation (23.8 %) for navigated SEEG. For robot-assisted SEEG, either RNS implantation (68.2 %) or laser ablation (22.7 %) were performed or offered. A majority of navigated and robot-assisted patients who underwent epilepsy surgery achieved either Engel Class I (navigated 36.8 %, robot-assisted 31.6 %) or II (navigated 36.8 %, robot-assisted 15.8 %) outcome with no significant difference between the groups (P = 0.14). Direct hospital cost for robot-assisted SEEG was 10 % higher than non-robotic cases.

CONCLUSION

This single-institutional study suggests that robotic assistance can enhance efficiency of SEEG without compromising safety or precision when compared to image guidance only. Adoption of this technique with uniform safety and efficacy over a short period of time is feasible with favorable epilepsy outcomes.

Robotic-Assisted Spine Surgery: History, Efficacy, Cost, And Future Trends

Robot-assisted spine surgery has recently emerged as a viable tool to enable less invasive and higher precision surgery. The first-ever spine robot, the SpineAssist (Mazor Robotics Ltd., Caesarea, Israel), gained FDA approval in 2004. With its ability to provide real-time intraoperative navigation and rigid stereotaxy, robotic-assisted surgery has the potential to increase accuracy while decreasing radiation exposure, complication rates, operative time, and recovery time. Currently, robotic assistance is mainly restricted to spinal fusion and instrumentation procedures, but recent studies have demonstrated its use in increasingly complex procedures such as spinal tumor resections and ablations, vertebroplasties, and deformity correction. However, robots do require high initial costs and training, and thus, require justification for their incorporation into common practice. In this review, we discuss the history of spinal robots along as well as currently available systems. We then examine the literature to evaluate accuracy, operative time, complications, radiation exposure, and costs – comparing robotic-assisted to traditional fluoroscopy-assisted freehand approaches. Finally, we consider future applications for robots in spine surgery.

Graft Materials and Biologics for Spinal Interbody Fusion

Spinal fusion is the most widely performed procedure in spine surgery. It is the preferred treatment for a wide variety of pathologies including degenerative disc disease, spondylolisthesis, segmental instability, and deformity. Surgeons have the choice of fusing vertebrae by utilizing cages containing autografts, allografts, demineralized bone matrices (DBMs), or graft substitutes such as ceramic scaffolds. Autografts from the iliac spine are the most commonly used as they offer osteogenic, osteoinductive, and osteoconductive capabilities, all while avoiding immune system rejection. Allografts obtained from cadavers and living donors can also be advantageous as they lack the need for graft extraction from the patient. DBMs are acid-extracted organic allografts with osteoinductive properties. Ceramic grafts containing hydroxyapatite can be readily manufactured and are able to provide osteoinductive support while having a long shelf life. Further, bone-morphogenetic proteins (BMPs), mesenchymal stem cells (MSCs), synthetic peptides, and autologous growth factors are currently being optimized to assist in improving vertebral fusion. Genetic therapies utilizing viral transduction are also currently being devised. This review provides an overview of the advantages, disadvantages, and future directions of currently available graft materials. The current literature on growth factors, stem cells, and genetic therapy is also discussed.

Anatomic and Thermometric Analysis of Cranial Nerve Palsy after Laser Amygdalohippocampotomy for Mesial Temporal Lobe Epilepsy

BACKGROUND

Laser interstitial thermal therapy (LITT) is a minimally invasive therapy for treating medication-resistant mesial temporal lobe epilepsy. Cranial nerve (CN) palsy has been reported as a procedural complication, but the mechanism of this complication is not understood.

OBJECTIVE

To identify the cause of postoperative CN palsy after LITT.

METHODS

Four medial temporal lobe epilepsy patients with CN palsy after LITT were identified for comparison with 22 consecutive patients with no palsy. We evaluated individual variation in the distance between CN III and the uncus, and CN IV and the parahippocampal gyrus using preoperative T1- and T2-weighted magnetic resonance (MR) images. Intraoperative MR thermometry was used to estimate temperature changes.

RESULTS

CN III (n = 2) and CN IV palsies (n = 2) were reported. On preoperative imaging, the majority of identified CN III (54%) and CN IV (43%) were located within 1 to 2 mm of the uncus and parahippocampal gyrus tissue border, respectively. Affected CN III and CN IV were more likely to be found &lt; 1 mm of the tissue border (PCNIII = .03, PCNIV &lt; .01; chi-squared test). Retrospective assessment of thermal profile during ablation showed higher temperature rise along the mesial temporal lobe tissue border in affected CNs than unaffected CNs after controlling for distance (12.9°C vs 5.8°C; P = .03; 2-sample t-test).

CONCLUSION

CN palsy after LITT likely results from direct heating of the respective CN running at extreme proximity to the mesial temporal lobe. Low-temperature thresholds set at the border of the mesial temporal lobe in patients whose CNs are at close proximity may reduce this risk.

Reliability of the 6-minute walking test smartphone application

OBJECTIVE

Objective functional measures such as the 6-minute walking test (6WT) are increasingly applied to evaluate patients with degenerative diseases of the lumbar spine before and after (surgical) treatment. However, the traditional 6WT is cumbersome to apply, as it requires specialized in-hospital infrastructure and personnel. The authors set out to compare 6-minute walking distance (6WD) measurements obtained with a newly developed smartphone application (app) and those obtained with the gold-standard distance wheel (DW).

METHODS

The authors developed a free iOS- and Android-based smartphone app that allows patients to measure the 6WD in their home environment using global positioning system (GPS) coordinates. In a laboratory setting, the authors obtained 6WD measurements over a range of smartphone models, testing environments, and walking patterns and speeds. The main outcome was the relative measurement error (rME; in percent of 6WD), with |rME| < 7.5% defined as reliable. The intraclass correlation coefficient (ICC) for agreement between app- and DW-based 6WD was calculated.

RESULTS

Measurements (n = 406) were reliable with all smartphone types in neighborhood, nature, and city environments (without high buildings), as well as with unspecified, straight, continuous, and stop-and-go walking patterns (ICC = 0.97, 95% CI 0.97-0.98, p < 0.001). Measurements were unreliable indoors, in city areas with high buildings, and for predominantly rectangular walking courses. Walking speed had an influence on the ME, with worse accuracy (2% higher rME) for every kilometer per hour slower walking pace (95% CI 1.4%-2.5%, p < 0.001). Mathematical adjustment of the app-based 6WD for velocity-dependent error mitigated the rME (p < 0.011), attenuated velocity dependence (p = 0.362), and had a positive effect on accuracy (ICC = 0.98, 95% CI 0.98-0.99, p < 0.001).

CONCLUSIONS

The new, free, spine-specific 6WT smartphone app measures the 6WD conveniently by using GPS coordinates, empowering patients to independently determine their functional status before and after (surgical) treatment. Measurements of 6WD obtained for the target population under the recommended circumstances are highly reliable.

Grade II Spondylolisthesis: Reverse Bohlman Procedure with Transdiscal S1-L5 and S2 Alar Iliac Screws Placed with Robotic Guidance

BACKGROUND

Grade II spondylolisthesis remains a complex surgical pathology for which there is no consensus regarding optimal surgical strategies. Surgical strategies vary regarding extent of reduction, use of instrumentation/interbody support, and anterior versus posterior approaches with or without decompression. Here we provide the first report on the efficacy of robotic spinal surgery systems in support of the treatment of grade II spondylolisthesis.

METHODS

Using 2 illustrative cases, we provide a technical report describing how robotic spinal surgery platform can be used to treatment grade II spondylolisthesis with a novel instrumentation strategy.

RESULTS

We describe how the "reverse Bohlman" technique to achieve a large anterior fusion construct spanning the pathological level and buttressed by the adjacent level above, coupled with a novel, high-fidelity posterior fixation scheme with transdiscal S1-L5 and S2 alar iliac (S2AI) screws placed in a minimally invasive fashion with robot guidance allows for the best chance of fusion in situ.

CONCLUSIONS

The reverse Bohlman technique coupled with transdiscal S1-L5 and S2AI screw fixation accomplishes the surgical goals of creating a solid fusion construct, avoiding neurologic injury with aggressive reduction, and halting the progression of anterolisthesis. The use of robot guidance allows for efficient placement of these difficult screw trajectories in a minimally invasive fashion.

Stereotactic laser ablation for completion corpus callosotomy

OBJECTIVE

Completion corpus callosotomy can offer further remission from disabling seizures when a prior partial corpus callosotomy has failed and residual callosal tissue is identified on imaging. Traditional microsurgical approaches to section residual fibers carry risks associated with multiple craniotomies and the proximity to the medially oriented motor cortices. Laser interstitial thermal therapy (LITT) represents a minimally invasive approach for the ablation of residual fibers following a prior partial corpus callosotomy. Here, the authors report clinical outcomes of 6 patients undergoing LITT for completion corpus callosotomy and characterize the radiological effects of ablation.

METHODS

A retrospective clinical review was performed on a series of 6 patients who underwent LITT completion corpus callosotomy for medically intractable epilepsy at Stanford University Medical Center and Lucile Packard Children's Hospital at Stanford between January 2015 and January 2018. Detailed structural and diffusion-weighted MR images were obtained prior to and at multiple time points after LITT. In 4 patients who underwent diffusion tensor imaging (DTI), streamline tractography was used to reconstruct and evaluate tract projections crossing the anterior (genu and rostrum) and posterior (splenium) parts of the corpus callosum. Multiple diffusion parameters were evaluated at baseline and at each follow-up.

RESULTS

Three pediatric (age 8-18 years) and 3 adult patients (age 30-40 years) who underwent completion corpus callosotomy by LITT were identified. Mean length of follow-up postoperatively was 21.2 (range 12-34) months. Two patients had residual splenium, rostrum, and genu of the corpus callosum, while 4 patients had residual splenium only. Postoperative complications included asymptomatic extension of ablation into the left thalamus and transient disconnection syndrome. Ablation of the targeted area was confirmed on immediate postoperative diffusion-weighted MRI in all patients. Engel class I-II outcomes were achieved in 3 adult patients, whereas all 3 pediatric patients had Engel class III-IV outcomes. Tractography in 2 adult and 2 pediatric patients revealed time-dependent reduction of fractional anisotropy after LITT.

CONCLUSIONS

LITT is a safe, minimally invasive approach for completion corpus callosotomy. Engel outcomes for completion corpus callosotomy by LITT were similar to reported outcomes of open completion callosotomy, with seizure reduction primarily observed in adult patients. Serial DTI can be used to assess the presence of tract projections over time but does not classify treatment responders or nonresponders.

Effects of surgical targeting in laser interstitial thermal therapy for mesial temporal lobe epilepsy: A multicenter study of 234 patients

OBJECTIVE

Laser interstitial thermal therapy (LITT) for mesial temporal lobe epilepsy (mTLE) has reported seizure freedom rates between 36% and 78% with at least 1 year of follow-up. Unfortunately, the lack of robust methods capable of incorporating the inherent variability of patient anatomy, the variability of the ablated volumes, and clinical outcomes have limited three-dimensional quantitative analysis of surgical targeting and its impact on seizure outcomes. We therefore aimed to leverage a novel image-based methodology for normalizing surgical therapies across a large multicenter cohort to quantify the effects of surgical targeting on seizure outcomes in LITT for mTLE.

METHODS

This multicenter, retrospective cohort study included 234 patients from 11 centers who underwent LITT for mTLE. To investigate therapy location, all ablation cavities were manually traced on postoperative magnetic resonance imaging (MRI), which were subsequently nonlinearly normalized to a common atlas space. The association of clinical variables and ablation location to seizure outcome was calculated using multivariate regression and Bayesian models, respectively.

RESULTS

Ablations including more anterior, medial, and inferior temporal lobe structures, which involved greater amygdalar volume, were more likely to be associated with Engel class I outcomes. At both 1 and 2 years after LITT, 58.0% achieved Engel I outcomes. A history of bilateral tonic-clonic seizures decreased chances of Engel I outcome. Radiographic hippocampal sclerosis was not associated with seizure outcome.

SIGNIFICANCE

LITT is a viable treatment for mTLE in patients who have been properly evaluated at a comprehensive epilepsy center. Consideration of surgical factors is imperative to the complete assessment of LITT. Based on our model, ablations must prioritize the amygdala and also include the hippocampal head, parahippocampal gyrus, and rhinal cortices to maximize chances of seizure freedom. Extending the ablation posteriorly has diminishing returns. Further work is necessary to refine this analysis and define the minimal zone of ablation necessary for seizure control.

Expenditures and Health Care Utilization Among Adults With Newly Diagnosed Low Back and Lower Extremity Pain

IMPORTANCE

Low back pain (LBP) with or without lower extremity pain (LEP) is one of the most common reasons for seeking medical care. Previous studies investigating costs in this population targeted patients receiving surgery. Little is known about health care utilization among patients who do not undergo surgery.

OBJECTIVES

To assess use of health care resources for LBP and LEP management and analyze associated costs.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used a retrospective analysis of a commercial database containing inpatient and outpatient data for more than 75 million individuals. Participants were US adults who were newly diagnosed with LBP or LEP between 2008 and 2015, did not have a red-flag diagnosis, and were opiate naive prior to diagnosis. Dates of analysis were October 6, 2018, to March 7, 2019.

EXPOSURES

Newly diagnosed LBP or LEP.

MAIN OUTCOMES AND MEASURES

The primary outcome was total cost of care within the first 6 and 12 months following diagnosis, stratified by whether patients received spinal surgery. An assessment was performed to determine whether patients who did not undergo surgery received care in accordance with proposed guidelines for conservative LBP and LEP management. Costs resulting from use of different health care services were estimated.

RESULTS

A total of 2 498 013 adult patients with a new LBP or LEP diagnosis (median [interquartile range] age, 47 [36-58] years; 1 373 076 [55.0%] female) were identified. More than half (55.7%) received no intervention. Only 1.2% of patients received surgery, but they accounted for 29.3% of total 12-month costs ($784 million). Total costs of care among the 98.8% of patients who did not receive surgery were $1.8 billion. Patients who did not undergo surgery frequently received care that was inconsistent with clinical guidelines for LBP and LEP: 32.3% of these patients received imaging within 30 days of diagnosis and 35.3% received imaging without a trial of physical therapy.

CONCLUSIONS AND RELEVANCE

The findings suggest that surgery is rare among patients with newly diagnosed LBP and LEP but remains a significant driver of spending. Early imaging in patients who do not undergo surgery was also a major driver of increased health care expenditures. Avoidable costs among patients with typically self-limited conditions result in considerable economic burden to the US health care system.

Focal Intramedullary Spinal Cord Lesion in Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome: Toxoplasmosis Versus Lymphoma

BACKGROUND

Neurologic complications are common in patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Although both the central nervous system (CNS) and the peripheral nervous system can be affected, 80% of patients with HIV/AIDS have CNS involvement during the course of their illness. The brain is the primary site of HIV/AIDS-associated CNS complications. Spinal cord involvement is rare, particularly focal intramedullary spinal cord lesions without any associated cerebral lesions. Among various opportunistic infections and malignancies, toxoplasmosis and CNS lymphoma are the most common causes of focal neurologic disease in patients with HIV/AIDS. Distinguishing between toxoplasmosis and CNS lymphoma is challenging, as the diseases have similar clinical presentations.

CASE DESCRIPTION

In a woman with newly diagnosed HIV infection, myelopathy manifested as an isolated, single intramedullary spinal cord lesion.

CONCLUSIONS

Common methods to distinguish the diagnoses of toxoplasmosis and CNS lymphoma are addressed. There should be a high index of suspicion for toxoplasmosis in patients with HIV/AIDS presenting with a focal intramedullary spinal cord lesion.

Brain abscess caused by Trueperella bernardiae in a child

Background:

Recurrent intracranial abscesses secondary to refractory otitis media present a challenge which demands multidisciplinary collaboration.

Case Description:

We present the first known case of pediatric brain abscess caused by a polymicrobial infection of Trueperella bernardiae, Actinomyces europaeus, and mixed anaerobic species resulting from acute-on-chronic suppurative left otitis media. This patient required two separate stereotactic abscess drainages and a complex course of antibiotics for successful management.

Conclusion:

Surgery is essential in the management of cerebral abscess both in agent identification and therapeutic drainage. Management of abscesses secondary to unusual and polymicrobial organisms often requires consultation from other medical and surgical specialties.

Topical vancomycin for surgical prophylaxis in non-instrumented pediatric spinal surgeries

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine if topical vancomycin irrigation reduces the incidence of post-operative surgical site infections following pediatric spinal procedures. Surgical site infections (SSIs) following spinal procedures performed in pediatric patients represent a serious complication. Prophylactic use of topical vancomycin prior to closure has been shown to be effective in reducing incidence of SSIs in adult spinal procedures. Non-instrumented cases make up the majority of spinal procedures in pediatric patients, and the efficacy of prophylactic topical vancomycin in these procedures has not previously been reported.

METHODS

This retrospective study reviewed all non-instrumented spinal procedures performed over a period from 05/2014-12/2016 for topical vancomycin use, surgical site infections, and clinical variables associated with SSI. Topical vancomycin was utilized as infection prophylaxis, and applied as a liquid solution within the wound prior to closure.

RESULTS

Ninety-five consecutive, non-instrumented, pediatric spinal surgeries were completed between 01/2015 and 12/2016, of which the last 68 utilized topical vancomycin. There was a 11.1% SSI rate in the non-topical vancomycin cohort versus 0% in the topical vancomycin cohort (P = 0.005). The number needed to treat was 9. There were no significant differences in risk factors for SSI between cohorts. There were no complications associated topical vancomycin use.

CONCLUSIONS

Routine topical vancomycin administration during closure of non-instrumented spinal procedures can be a safe and effective tool for reducing SSIs in the pediatric neurosurgical population.

Contralateral acute vascular occlusion following revascularization surgery for moyamoya disease

OBJECTIVE

Revascularization surgery is a safe and effective surgical treatment for symptomatic moyamoya disease (MMD) and has been shown to reduce the frequency of future ischemic events and improve quality of life in affected patients. The authors sought to investigate the occurrence of acute perioperative occlusion of the contralateral internal carotid artery (ICA) with contralateral stroke following revascularization surgery, a rare complication that has not been previously reported.

METHODS

This study is a retrospective review of a prospective database of a single surgeon's series of revascularization operations in patients with MMD. From 1991 to 2016, 1446 bypasses were performed in 905 patients, 89.6% of which involved direct anastomosis of the superficial temporal artery (STA) to a distal branch of the middle cerebral artery (MCA). Demographic, surgical, and radiographic data were collected prospectively in all treated patients.

RESULTS

Symptomatic contralateral hemispheric infarcts occurred during the postoperative period in 34 cases (2.4%). Digital subtraction angiography (DSA) was performed in each of these patients. In 8 cases (0.6%), DSA during the immediate postoperative period revealed associated new occlusion of the contralateral ICA. In each of these cases, revascularization surgery involved direct anastomosis of the STA to an M4 branch of the MCA. Preoperative DSA revealed moderate (n = 1) or severe (n = 3) stenosis or occlusion (n = 4) of the ipsilateral ICA and mild (n = 2), moderate (n = 4), or severe (n = 2) stenosis of the contralateral ICA. The baseline Suzuki stage was 4 (n = 7) or 5 (n = 1). The collateral supply originated exclusively from the intracranial circulation in 4/8 patients (50%), and from both the intracranial and extracranial circulation in the remaining 50% of patients. Seven (88%) of 8 patients improved symptomatically during the acute postoperative period with induced hypertension. The modified Rankin Scale (mRS) score at discharge was worse than baseline in 7/8 patients (88%), whereas 1 patient had only minor deficits that did not affect the mRS score. At the 3-year follow-up, 3/8 patients (38%) were at their baseline mRS score or better, 1 patient had significant disability compared with preoperatively, 2 patients had died, and 1 patient was lost to follow-up. Three-year follow-up is not yet available in 1 patient.

CONCLUSIONS

Acute occlusion of the ICA on the contralateral side from an STA-MCA bypass is a rare, but potentially serious, complication of revascularization surgery for MMD. It highlights the importance of the hemodynamic interrelationships that exist between the two hemispheres, a concept that has been previously underappreciated. Induced hypertension during the acute period may provide adequate cerebral blood flow via developing collateral vessels, and good outcomes may be achieved with aggressive supportive management and expedited contralateral revascularization.

Topical vancomycin surgical prophylaxis in pediatric open craniotomies: an institutional experience

OBJECTIVETopical antimicrobial compounds are safe and can reduce cost and complications associated with surgical site infections (SSIs). Topical vancomycin has been an effective tool for reducing SSIs following routine neurosurgical procedures in the spine and following adult craniotomies. However, widespread adoption within the pediatric neurosurgical community has not yet occurred, and there are no studies to report on the safety and efficacy of this intervention. The authors present the first institution-wide study of topical vancomycin following open craniotomy in the pediatric population.METHODSIn this retrospective study the authors reviewed all open craniotomies performed over a period from 05/2014 to 12/2016 for topical vancomycin use, SSIs, and clinical variables associated with SSI. Topical vancomycin was utilized as an infection prophylaxis and was applied as a liquid solution following replacement of a bone flap or after dural closure when no bone flap was reapplied.RESULTSOverall, 466 consecutive open craniotomies were completed between 05/2014 and 12/2016, of which 43% utilized topical vancomycin. There was a 1.5% SSI rate in the nontopical cohort versus 0% in the topical vancomycin cohort (p = 0.045). The number needed to treat was 66. There were no significant differences in risk factors for SSI between cohorts. There were no complications associated with topical vancomycin use.CONCLUSIONSRoutine topical vancomycin administration during closure of open craniotomies can be a safe and effective tool for reducing SSIs in the pediatric neurosurgical population.

Robot-guided pediatric stereoelectroencephalography: single-institution experience

OBJECTIVEStereoelectroencephalography (SEEG) has increased in popularity for localization of epileptogenic zones in drug-resistant epilepsy because safety, accuracy, and efficacy have been well established in both adult and pediatric populations. Development of robot-guidance technology has greatly enhanced the efficiency of this procedure, without sacrificing safety or precision. To date there have been very limited reports of the use of this new technology in children. The authors present their initial experience using the ROSA platform for robot-guided SEEG in a pediatric population.METHODSBetween February 2016 and October 2017, 20 consecutive patients underwent robot-guided SEEG with the ROSA robotic guidance platform as part of ongoing seizure localization and workup for medically refractory epilepsy of several different etiologies. Medical and surgical history, imaging and trajectory plans, as well as operative records were analyzed retrospectively for surgical accuracy, efficiency, safety, and epilepsy outcomes.RESULTSA total of 222 leads were placed in 20 patients, with an average of 11.1 leads per patient. The mean total case time (± SD) was 297.95 (± 52.96) minutes and the mean operating time per lead was 10.98 minutes/lead, with improvements in total (33.36 minutes/lead vs 21.76 minutes/lead) and operative (13.84 minutes/lead vs 7.06 minutes/lead) case times/lead over the course of the study. The mean radial error was 1.75 (± 0.94 mm). Clinically useful data were obtained from SEEG in 95% of cases, and epilepsy surgery was indicated and performed in 95% of patients. In patients who underwent definitive epilepsy surgery with at least a 3-month follow-up, 50% achieved an Engel class I result (seizure freedom). There were no postoperative complications associated with SEEG placement and monitoring.CONCLUSIONSIn this study, the authors demonstrate that rapid adoption of robot-guided SEEG is possible even at a SEEG-naïve institution, with minimal learning curve. Use of robot guidance for SEEG can lead to significantly decreased operating times while maintaining safety, the overall goals of identification of epileptogenic zones, and improved epilepsy outcomes.