Prophylactic Radiotherapy Of MInimally Symptomatic Spinal Disease (PROMISSeD): study protocol for a randomized controlled trial

BACKGROUND

Early palliative/pre-emptive intervention improves clinical outcomes and quality of life for patients with metastatic cancer. A previous signal-seeking randomized controlled trial (RCT) demonstrated that early upfront radiotherapy to asymptomatic or minimally symptomatic high-risk osseous metastases led to reduction in skeletal-related events (SREs), a benefit driven primarily by subgroup of high-risk spine metastasis. The current RCT aims to determine whether early palliative/pre-emptive radiotherapy in patients with high-risk, asymptomatic or minimally symptomatic spine metastases will lead to fewer SREs within 1 year.

METHODS

This is a single-center, parallel-arm, in-progress RCT in adults (≥ 18 years) with ECOG performance status 0-2 and asymptomatic or minimally symptomatic (not requiring opioids) high-risk spine metastases from histologically confirmed solid tumor malignancies with > 5 sites of metastatic disease on cross-sectional imaging. High-risk spine metastases are defined by the following: (a) bulkiest disease sites ≥ 2 cm; (b) junctional disease (occiput to C2, C7-T1, T12-L2, L5-S1); (c) posterior element involvement; or (d) vertebral body compression deformity > 50%. Patients are randomized 1:1 to receive either standard-of-care systemic therapy (arm 1) or upfront, early radiotherapy to ≤ 5 high-risk spine lesions plus standard-of-care systemic therapy (arm 2), in the form of 20-30 Gy of radiation in 2-10 fractions. The primary endpoint is SRE, a composite outcome including spinal fracture, spinal cord compression, need for palliative radiotherapy, interventional procedures, or spinal surgery. Secondary endpoints include (1) surrogates of health care cost, including the number and duration of SRE-related hospitalizations; (2) overall survival; (3) pain-free survival; and (4) quality of life. Study instruments will be captured pre-treatment, at baseline, during treatment, and at 1, 3, 6, 12, and 24 months post-treatment. The trial aims to accrue 74 patients over 2 years to achieve > 80% power in detecting difference using two-sample proportion test with alpha < 0.05.

DISCUSSION

The results of this RCT will demonstrate the value, if any, of early radiotherapy for high-risk spine metastases. The trial has received IRB approval, funding, and prospective registration (NCT05534321) and has been open to accrual since August 19, 2022. If positive, the trial will expand the scope and utility of spine radiotherapy.

TRIAL REGISTRATION

ClinicalTrials.Gov NCT05534321 . Registered September 9, 2022.

TRIAL STATUS

Version 2.0 of the protocol (2021-KOT-002), revised last on September 2, 2022, was approved by the WCG institutional review board (Study Number 1337188, IRB tracking number 20223735). The trial was first posted on ClinicalTrials.Gov on September 9, 2022 (NCT05534321). Patient enrollment commenced on August 19, 2022, and is expected to be completed in 2 years, likely by August 2024.

Initial experience with minimally invasive endoscopic evacuation of intracerebral hemorrhage in the setting of radiographic herniation

BACKGROUND

Spontaneous intracerebral hemorrhage (ICH) can rapidly result in cerebral herniation, leading to poor neurologic outcomes or mortality. To date, neither decompressive hemicraniectomy (DH) nor hematoma evacuation have been conclusively shown to improve outcomes for comatose ICH patients presenting with cerebral herniation, with these patients largely excluded from clinical trials. Here we present the outcomes of a series of patients presenting with ICH and radiographic herniation who underwent emergent minimally invasive (MIS) ICH evacuation.

METHODS

We reviewed our prospectively collected registry of patients undergoing MIS ICH evacuation at a single institution from 01/01/2017 to 10/01/2021. We selected all consecutive patients with Glasgow coma scale (GCS) ≤ 8 and radiographic herniation for this case series. Clinical and radiographic variables were collected, including admission GCS score, preoperative and postoperative hematoma volumes, National Institute of Health stroke scale (NIHSS) scores, and modified Rankin scale (mRS) scores at last follow-up.

RESULTS

Of 176 patients with spontaneous supratentorial ICH who underwent minimally invasive endoscopic evacuation during the study time period, a total of 9 patients presented with GCS ≤ 8 and evidence of radiographic herniation. Among these patients, the mean age was 62 ± 12 years, the median GCS at presentation was 5 [IQR 4-6], the mean preoperative hematoma volume was 94 ± 44 mL, the mean time from ictus to evacuation was 12 ± 5 h, and the mean postoperative hematoma volume was 11 ± 16 mL, for a median evacuation percentage of 97% [83-99]. Three patients (33%) died, four (44%) survived with mRS 5 and two (22%) with mRS 4. Patients had a median NIHSS improvement of 5 compared to their initial NIHSS. Age was very strongly correlate to improvements in NIHSS (r2 = 0.90).

CONCLUSION

Data from this initial experience suggest emergent MIS hematoma evacuation in the setting of ICH with radiographic herniation is feasible and technically effective. Further randomized studies are required to determine if such an intervention offers overall benefits to patients and their families.

Responder Analysis of Pain Relief After Surgery for the Treatment of Spinal Metastatic Tumors

BACKGROUND

Central tendency analysis studies demonstrate that surgery provides pain relief in spinal metastatic tumors. However, they preclude patient-specific probability of treatment outcome.

OBJECTIVE

To use responder analysis to study the variability of pain improvement.

METHODS

In this single-center, retrospective analysis, 174 patients were studied. Logistic regression modeling was used to associate preoperative characteristics with rating the Brief Pain Inventory (BPI) worst pain item 0 to 4. Linear regression modeling was used to associate preoperative characteristics with minimal clinically important improvement (MCI) in physical functioning defined by a 1-point decrease in the BPI Interference Construct score from preoperative baseline to 6 months postoperatively.

RESULTS

Patient-level analysis revealed that 60% of patients experienced an improvement in pain. At least half experienced a decrease in pain resulting in MCI in physical functioning. Cutpoint analysis revealed that 48% were responders. Increasing scores on the preoperative pain intensity BPI items, the MD Anderson Symptom Inventory (MDASI) Core Symptom Severity Construct, the MDASI Spine Tumor-Specific Construct, the presence of preoperative neurologic deficits, and postoperative complications were associated with lower probability of treatment success while increasing severity in all BPI pain items, and MDASI constructs were associated with increased probability of MCI in physical function. Significant mortality and loss to follow-up intrinsic to this patient population limit the strength of these data.

CONCLUSION

Although patients with milder preoperative symptoms are likely to achieve better pain relief after surgery, patients with worse preoperative symptom also benefit from surgery with adequate pain relief with an improvement in physical function.

The Impact of Diabetes on Outcomes and Health Care Costs Following Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Anterior cervical discectomy and fusion (ACDF) is commonly used to treat an array of cervical spine pathology and is associated with good outcomes and low complication rates. Diabetes mellitus (DM) is a common comorbidity for patients undergoing ACDF, but the literature is equivocal about the impact it has on outcomes. Because DM is a highly prevalent comorbidity, it is crucial to determine if it is an associated risk factor for outcomes after ACDF procedures.

METHODS

Patients at a single institution from 2008 to 2016 undergoing ACDF were compared on the basis of having a prior diagnosis of DM versus no DM. The 2 cohorts were compared utilizing univariate tests and multivariate logistic and linear regressions.

RESULTS

Data for 2470 patients was analyzed. Diabetic patients had significantly higher Elixhauser scores (P < .0001). Univariate testing showed diabetic patients were more likely to suffer from sepsis (0.82% vs 0.10%, P = .03) and bleeding complications (3.0% vs 1.5%, P = .04). In multivariate analyses, diabetic patients had higher rates of non-home discharge (odds ratio [OR] = 1.37, 95% confidence interval [CI] = 1.07-1.75, P = .013) and prolonged length of stay (OR = 1.95, 95% CI = 1.25-3.05, P = .003), but similar complication (OR = 1.46, 95% CI = 0.85-2.52, P = .17), reoperation (OR = 0.77, 95% CI = 0.33-1.81, P = .55), and 90-day readmission (OR = 1.53, 95% CI = 0.97-2.43) rates compared to nondiabetic patients. Direct cost was also shown to be similar between the cohorts after adjusting for patient, surgical, and hospital-related factors (estimate = -$30.25, 95% CI = -$515.69 to $455.18, P = .90).

CONCLUSIONS

Diabetic patients undergoing ACDF had similar complication, reoperation, and readmission rates, as well as similar cost of care compared to nondiabetic patients.

The Impact of Non-Elective Admission on Cost of Care and Length of Stay in Anterior Cervical Discectomy and Fusion: A Propensity-Matched Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate the impact of admission status on patient outcomes and healthcare costs in anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Undergoing ACDF non-electively has been associated with higher patient comorbidity burdens. However, the impact of non-elective status on the total cost of hospital stay has yet to be quantified.

METHODS

Patients undergoing ACDF at a single institution were placed into elective or non-elective cohorts. Propensity score-matching analysis in a 5:1 ratio controlling for insurance type and comorbidities was used to minimize selection bias. Demographics were compared by univariate analysis. Cost of care, length of stay (LOS), and clinical outcomes were compared between groups using multivariable linear and logistic regression with elective patients as reference cohort. All analyses controlled for sex, preoperative diagnosis, elixhauser comorbidity index (ECI), age, length of surgery, number of segments fused, and insurance type.

RESULTS

Of 708 patients in the final ACDF cohort, 590 underwent an elective procedure and 118 underwent a non-elective procedure. The non-elective group was significantly younger (53.7 vs. 49.5 yr; P = 0.0007). Cohorts had similar proportions of private versus public health insurance, although elective had higher rates of commercial insurance (39.22% vs. 15.25%; P < 0.0001) and non-elective had higher rates of managed care (32.77% vs. 56.78%; P < 0.0001). Operation duration was significantly longer in non-elective patients (158 vs. 177 minutes; P = 0.01). Adjusted analysis also demonstrated that admission status independently affected cost (+$6877, 95% confidence interval [CI]: $4906-$8848; P < 0.0001) and LOS (+4.9 days, 95% CI: 3.9-6.0; P < 0.0001) for the non-elective cohort. The non-elective cohort was significantly more likely to return to the operating room (OR: 3.39; 95% CI: 1.37-8.36, P = 0.0008) and experience non-home discharge (OR: 10.95; 95% CI: 5.00-24.02, P < 0.0001).

CONCLUSION

Patients undergoing ACDF non-electively had higher cost of care and longer LOS, as well as higher rates of postoperative adverse outcomes.Level of Evidence: 3.

Challenges in Diagnosis and Management of Previously Embolized Spinal Dural Arteriovenous Fistulae

BACKGROUND

Given the growing prevalence of initial endovascular treatment for type 1 spinal dural arteriovenous fistulae (dAVF), there are an increasing number of patients presenting with progressive symptoms related to recurrent previously embolized spinal dAVF. This study's goal was to identify demographic, clinical, and radiographic variables among patients who have failed embolization of type I spinal dAVF.

METHODS

A retrospective review of 24 consecutive surgeries for type I spinal dAVF performed by the senior author (A.D.L.) identified 5 patients who underwent open surgery for failed embolization. These 5 cases were reviewed for location of fistula, time from embolization to recurrence, preoperative functional status, fistulous point encountered at surgery, and clinical outcome of the patient at 3-month follow-up. A representative example case is reviewed in detail.

RESULTS

The median age at time of recurrence was 63 years (range 51-73 years). The median timing of embolization to recurrence of neurologic symptoms was 5 months (range 1-54) and to surgery 7 months (range 2-60 months). The level of the spinal dAVF was most frequently at T12-L1 (n = 3). Spinal magnetic resonance arteriography led to localization of the spinal dAVF in 2 patients and spinal catheter angiogram in 3 cases. All patients had definitive radiographic cure of the dAVF at last clinical follow-up.

CONCLUSIONS

The increased use of endovascular treatment of spinal dAVF has led to the treatment of refractory cases with a greater degree of surgical complexity. Open surgical ligation continues to provide the most definitive treatment outcomes for this complex spinal vascular entity.

Syrinx shunts for syringomyelia: a systematic review and meta-analysis of syringosubarachnoid, syringoperitoneal, and syringopleural shunting

OBJECTIVE

Syringomyelia is a debilitating, progressive disease process that can lead to loss of neurological function in patients already experiencing significant compromise. Syringosubarachnoid, syringoperitoneal, and syringopleural shunts are accepted treatment options for patients with persistent syringomyelia, but direct comparisons have been lacking to date. The authors conducted a systematic review of the literature and meta-analysis to compare clinical outcomes between these three syrinx shunt modalities.

METHODS

Utilizing PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews, Ovid Embase, PubMed, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, American College of Physicians Journal Club, and Database of Abstracts of Review of Effectiveness were searched to identify all potentially relevant studies published from inception until July 2020. Data were extracted and analyzed using meta-analysis of proportions. The primary study outcome was the rate of reoperation based on the initial shunt modality. Secondary outcomes included clinical improvement, clinical deterioration, and complications following shunt placement.

RESULTS

A total of 22 articles describing 27 distinct treatment cohorts published between 1984 and 2019 satisfied the inclusion criteria. This captured 473 syrinx shunt procedures, 193 (41%) by syringosubarachnoid shunt, 153 (32%) by syringoperitoneal shunt, and 127 (27%) by syringopleural shunt, with an overall median clinical follow-up of 44 months. The pooled incidences of revision surgery were estimated as 13% for syringosubarachnoid, 28% for syringoperitoneal, and 10% for syringopleural shunts, respectively (p-interaction = 0.27). The rate of clinical improvement was estimated as 61% for syringosubarachnoid, 64% for syringoperitoneal, and 71% for syringopleural shunts. The rate of clinical deterioration following placement was estimated as 13% for syringosubarachnoid, 13% for syringoperitoneal, and 10% for syringopleural shunts.

CONCLUSIONS

The preferred modality of syrinx shunting remains a controversial topic for symptomatic syringomyelia. This study suggests that while all three modalities offer similar rates of clinical improvement and deterioration after placement, syringoperitoneal shunts have a greater rate of malfunction requiring surgical revision. These data also suggest that syringopleural shunts may offer the best rate of clinical improvement with the lowest rate of reoperation.

Advanced Techniques for Endoscopic Intracerebral Hemorrhage Evacuation: A Technical Report With Case Examples

BACKGROUND

Multiple surgical techniques to perform minimally invasive intracerebral hemorrhage (ICH) evacuation are currently under investigation. The use of an adjunctive aspiration device permits controlled suction through an endoscope, minimizing collateral damage from the access tract. As with increased experience with any new procedure, performance of endoscopic minimally invasive ICH evacuation requires development of a unique set of operative tenets and techniques.

OBJECTIVE

To describe operative nuances of endoscopic minimally invasive ICH evacuation developed at a single center over an experience of 80 procedures.

METHODS

Endoscopic minimally invasive ICH evacuation was performed on 79 consecutive eligible patients who presented a single Health System between March 2016 and May 2018. We summarize 4 core operative tenets and 4 main techniques used in 80 procedures.

RESULTS

A total of 80 endoscopic minimally invasive ICH evacuations were performed utilizing the described surgical techniques. The average preoperative and postoperative volumes were 49.5 mL (standard deviation [SD] 31.1 mL, interquartile range [IQR] 30.2) and 5.4 mL (SD 9.6, mL IQR 5.1), respectively, with an average evacuation rate of 88.7%. All cause 30-d mortality was 8.9%.

CONCLUSION

As experience builds with endoscopic minimally invasive ICH evacuation, academic discussion of specific surgical techniques will be critical to maximizing its safety and efficacy.

Application of Cooperative Game Theory Principles to Interpret Machine Learning Models of Nonhome Discharge Following Spine Surgery

STUDY DESIGN

Retrospective analysis of prospectively acquired data.

OBJECTIVE

The aim of this study was to identify interaction effects that modulate nonhome discharge (NHD) risk by applying coalitional game theory principles to interpret machine learning models and understand variable interaction effects underlying NHD risk.

SUMMARY OF BACKGROUND DATA

NHD may predispose patients to adverse outcomes during their care. Previous studies identified potential factors implicated in NHD; however, it is unclear how interaction effects between these factors contribute to overall NHD risk.

METHODS

Of the 11,150 reviewed cases involving procedures for degenerative spine conditions, 1764 cases (15.8%) involved NHD. Gradient boosting classifiers were used to construct predictive models for NHD for each patient. Shapley values, which assign a unique distribution of the total NHD risk to each model variable using an optimal cost-sharing rule, quantified feature importance and examined interaction effects between variables.

RESULTS

Models constructed from features identified by Shapley values were highly predictive of patient-level NHD risk (mean C-statistic = 0.91). Supervised clustering identified distinct patient subgroups with variable NHD risk and their shared characteristics. Focused interaction analysis of surgical invasiveness, age, and comorbidity burden suggested age as a worse risk factor than comorbidity burden due to stronger positive interaction effects. Additionally, negative interaction effects were found between age and low blood loss, indicating that intraoperative hemostasis may be critical for reducing NHD risk in the elderly.

CONCLUSION

This strategy provides novel insights into feature interactions that contribute to NHD risk after spine surgery. Patients with positively interacting risk factors may require special attention during their hospitalization to control NHD risk.Level of Evidence: 3.

Survival Trends After Surgery for Spinal Metastatic Tumors: 20-Year Cancer Center Experience

BACKGROUND

Over the last 2 decades, advances in systemic therapy have increased the expected overall survival for patients with cancer. It is unclear whether the same survival benefit has been conferred to patients requiring surgery for metastatic spinal disease.

OBJECTIVE

To examine trends in postoperative survival over a 20-yr period for patients surgically treated for spinal metastatic disease.

METHODS

Data were obtained for 1515 patients who underwent surgery for metastatic epidural spinal cord compression or tumor-related mechanical instability. Postoperative overall survival was calculated for all included patients using Kaplan-Meier methodology from date of surgery until death or last follow-up for those who were censored. Trends were analyzed using Cox proportional hazards modeling.

RESULTS

Patients with renal, breast, lung, and colon cancers experienced a statistically significant improvement in survival over time based on the year of surgery (40%-100% improvement over the study period), whereas the overall survival trend for the entire cohort did not reach statistical significance (P = .12, median survival 0.71 yr, 95% CI 0.63-0.78). Patients presenting with synchronous metastatic disease had better survival compared to those presenting with metachronous disease (median overall survival: 0.94 vs 0.63 yr, respectively; log-rank P-value = .00001).

CONCLUSION

The postoperative survival among patients with spinal metastases has improved over the past 20 yr, particularly in patients with kidney, breast, lung, and colon tumors metastatic to the spine. The observed survival improvement emphasizes the need for long-term outcome consideration in treatment decisions for patients undergoing surgery for spinal metastatic tumors.

Surgical Start Time Is Not Predictive of Microdiscectomy Outcomes

STUDY DESIGN

Retrospective analysis of clinical data from a single institution.

OBJECTIVE

The objective of this study was to assess the time of surgery as a possible predictor for outcomes, length of stay, and cost following microdiscectomy.

SUMMARY OF BACKGROUND DATA

The volume of microdiscectomy procedures has increased year over year, heightening interest in surgical outcomes. Previous investigations have demonstrated an association between time of procedures and clinical outcomes in various surgeries, however, no study has evaluated its influence on microdiscectomy.

METHODS

Demographic and outcome variables were collected from all patients that underwent a nonemergent microdiscectomy between 2008 and 2016. Patients were divided into 2 cohorts: those receiving surgery before 2 pm were assigned to the early group and those with procedures beginning after 2 pm were assigned to the late group. Outcomes and patient-level characteristics were compared using bivariate, multivariable logistic, and linear regression models. Adjusted length of stay and cost were coprimary outcomes. Secondary outcomes included operative complications, nonhome discharge, postoperative emergency department visits, or readmission rates.

RESULTS

Of the 1261 consecutive patients who met the inclusion criteria, 792 were assigned to the late group and 469 were assigned to the early group. There were no significant differences in demographics or baseline characteristics between the 2 cohorts. In the unadjusted analysis, mean length of stay was 1.80 (SD=1.82) days for the early group and 2.00 (SD=1.70) days for the late group (P=0.054). Mean direct cost for the early cohort was $5088 (SD=$4212) and $4986 (SD=$2988) for the late cohort (P=0.65). There was no difference in adjusted length of stay or direct cost. No statistically significant differences were found in operative complications, nonhome discharge, postoperative emergency department visits, or readmission rates between the 2 cohorts.

CONCLUSION

The study findings suggest that early compared with late surgery is not significantly predictive of surgical outcomes following microdiscectomy.

Lower Mortality and Morbidity with Low-Molecular-Weight Heparin for Venous Thromboembolism Prophylaxis in Spine Trauma

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

The objective of this study was to evaluate outcomes between patients receiving LMWH versus UH in a retrospective cohort of patients with spine trauma.

SUMMARY OF BACKGROUND DATA

Although multiple clinical trials have been conducted, current guidelines do not have enough evidence to suggest low-molecular-weight heparin (LMWH) or unfractionated heparin (UH) for venous thromboembolism (VTE) prophylaxis in spine trauma.

METHODS

Patients with spine trauma in the Trauma Quality Improvement Program datasets were identified. Those who died, were transferred within 72 hours, were deemed to have a fatal injury, were discharged within 24 hours, suffered from polytrauma, or were missing data for VTE prophylaxis were excluded. A propensity score was created using age, sex, severity of injury, time to prophylaxis, presence of a cord injury, and altered mental status or hypotension upon arrival, and inverse probability weighted logistic regression modeling was used to evaluate mortality, venous thromboembolic, return to operating room, and total complication rates. E values were used to calculate the likelihood of unmeasured confounders.

RESULTS

Those receiving UH (n = 7172) were more severely injured (P < 0.0001), with higher rates of spinal cord injury (32.26% vs. 25.32%, P < 0.0001) and surgical stabilization (29.52% vs. 22.94%, P < 0.0001) compared to those receiving LMWH (n = 20,341). Patients receiving LMWH had lower mortality (odds ratio [OR]: 0.47; 95% CI: 0.42-0.53; P < 0.001; E = 3.68), total complication (OR: 0.92; 95% CI: 0.88-0.95; P < 0.001; E = 1.39), and VTE event (OR: 0.80; 95% CI: 0.72-0.88; P < 0.001; E = 1.81) rates than patients receiving UH. There were no differences in rates of unplanned return to the operating room (OR: 1.01; 95% CI: 0.80-1.27; P = 0.93; E = 1.11).

CONCLUSION

There is an association between lower mortality and receiving LMWH for VTE prophylaxis in patients with spine trauma. A large randomized clinical trial is necessary to confirm these findings.

LEVEL OF EVIDENCE

3.

Utility of the Hospital Frailty Risk Score for Predicting Adverse Outcomes in Degenerative Spine Surgery Cohorts

BACKGROUND

As spine surgery becomes increasingly common in the elderly, frailty has been used to risk stratify these patients. The Hospital Frailty Risk Score (HFRS) is a novel method of assessing frailty using International Classification of Diseases, Tenth Revision (ICD-10) codes. However, HFRS utility has not been evaluated in spinal surgery.

OBJECTIVE

To assess the accuracy of HFRS in predicting adverse outcomes of surgical spine patients.

METHODS

Patients undergoing elective spine surgery at a single institution from 2008 to 2016 were reviewed, and those undergoing surgery for tumors, traumas, and infections were excluded. The HFRS was calculated for each patient, and rates of adverse events were calculated for low, medium, and high frailty cohorts. Predictive ability of the HFRS in a model containing other relevant variables for various outcomes was also calculated.

RESULTS

Intensive care unit (ICU) stays were more prevalent in high HFRS patients (66%) than medium (31%) or low (7%) HFRS patients. Similar results were found for nonhome discharges and 30-d readmission rates. Logistic regressions showed HFRS improved the accuracy of predicting ICU stays (area under the curve [AUC] = 0.87), nonhome discharges (AUC = 0.84), and total complications (AUC = 0.84). HFRS was less effective at improving predictions of 30-d readmission rates (AUC = 0.65) and emergency department visits (AUC = 0.60).

CONCLUSION

HFRS is a better predictor of length of stay (LOS), ICU stays, and nonhome discharges than readmission and may improve on modified frailty index in predicting LOS. Since ICU stays and nonhome discharges are the main drivers of cost variability in spine surgery, HFRS may be a valuable tool for cost prediction in this specialty.

Correction to: Adult spinal deformity surgery: the effect of surgical start time on patient outcomes and cost of care

The original version of this article unfortunately contained a mistake. The first name of the author "Samuel Z. Maron" was incorrectly provided as "Sam" instead of "Samuel".

By the Numbers Analysis of Effect of COVID-19 on a Neurosurgical Residency at the Epicenter

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 pandemic has created challenges to neurosurgical patient care. Despite editorials evaluating neurosurgery responses to 2019 novel coronavirus disease (COVID-19), data reporting effects of COVID-19 on neurosurgical case volume, census, and resident illness are lacking. The aim of this study was to present a real-world analysis of neurosurgical volumes, resident deployment, and unique challenges encountered during the severe acute respiratory syndrome coronavirus 2 outbreak peak in New York City.

METHODS

Daily census and case volume data were prospectively collected throughout the severe acute respiratory syndrome coronavirus 2 outbreak in spring 2020. Neurosurgical census was compared against COVID-19 system-wide data. Neurosurgical cases during the crisis were analyzed and compared with 7-week periods from 2019 and early 2020. Resident deployment and illness were reviewed.

RESULTS

From March 16, 2020, to May 5, 2020, residents participated in 72 operations and 69 endovascular procedures compared with 448 operations and 253 endovascular procedures from January 2020 to February 2020 and 530 operations and 340 endovascular procedures from March 2019 to May 2019. There was a 59% reduction in neurosurgical census during the outbreak (median 24 patients, 2.75 average total cases daily). COVID-19 neurosurgical admissions peaked in concert with the system-wide pandemic. Three residents demonstrated COVID-19 symptoms (no hospitalizations occurred) for a total 24 workdays lost (median 7 workdays).

CONCLUSIONS

These data provide real-world guidance on neurosurgical infrastructure needs during a COVID-19 outbreak. While redeployment to support the COVID-19 response was required, a significant need remained to continue to provide critical neurosurgical service.

Hypofractionated spinal stereotactic body radiation therapy for high-grade epidural disease

OBJECTIVE

To characterize the clinical outcomes when stereotactic body radiation therapy (SBRT) alone is used to treat high-grade epidural disease without prior surgical decompression, the authors conducted a retrospective cohort study of patients treated at the Memorial Sloan Kettering Cancer Center between 2014 and 2018. The authors report locoregional failure (LRF) for a cohort of 31 cases treated with hypofractionated SBRT alone for grade 2 epidural spinal cord compression (ESCC) with radioresistant primary cancer histology.

METHODS

High-grade epidural disease was defined as grade 2 ESCC, which is notable for radiographic deformation of the spinal cord by metastatic disease. Kaplan-Meier survival curves and cumulative incidence functions were generated to examine the survival and incidence experiences of the sample level with respect to overall survival, LRF, and subsequent requirement of vertebral same-level surgery (SLS) due to tumor progression or fracture. Associations with dosimetric analysis were also examined.

RESULTS

Twenty-nine patients undergoing 31 episodes of hypofractionated SBRT alone for grade 2 ESCC between 2014 and 2018 were identified. The 1-year and 2-year cumulative incidences of LRF were 10.4% (95% CI 0-21.9) and 22.0% (95% CI 5.5-38.4), respectively. The median survival was 9.81 months (95% CI 8.12-18.54). The 1-year cumulative incidence of SLS was 6.8% (95% CI 0-16.0) and the 2-year incidence of SLS was 14.5% (95% CI 0.6-28.4). All patients who progressed to requiring surgery had index lesions at the thoracic apex (T5-7).

CONCLUSIONS

In carefully selected patients, treatment of grade 2 ESCC disease with hypofractionated SBRT alone offers a 1-year cumulative incidence of LRF similar to that in low-grade ESCC and postseparation surgery adjuvant hypofractionated SBRT. Use of SBRT alone has a favorable safety profile and a low cumulative incidence of progressive disease requiring open surgical intervention (14.5%).

Large Rises in Thoracolumbar Fusions by 2040: A Cause for Concern with an Increasingly Elderly Surgical Population

BACKGROUND

With a growing aging population in the United States, the number of operative lumbar spine pathologies continues to grow. Therefore, our objective was to estimate the future demand for lumbar spine surgery volumes for the United States to the year 2040.

METHODS

The National/Nationwide Inpatient Sample was queried for years 2003-2015 for anterior interbody and posterior lumbar fusions (ALIF, PLF) to create national estimates of procedural volumes for those years. The average age and comorbidity burden was characterized, and Poisson modeling controlling for age and sex allowed for surgical volume prediction to 2040 in 10-year increments. Age was grouped into categories (<25, 25-34, 35-44, 45-54, 55-64, 65-74, 75-84, and >85 years), and estimates of surgical volumes for each age subgroup were created.

RESULTS

ALIF volume is expected to increase from 46,903 to 55,528, and PLF volume is expected to increase from 248,416 to 297,994 from 2020 to 2040. For ALIF, the largest increases are expected in the 45-54 years (10,316 to 12,216) and 75-84 years (2,898 to 5,340) age groups. Similarly the largest increases in PLF will be seen in the 65-74 years (71,087 to 77,786) and 75-84 years (28,253 to 52,062) age groups.

CONCLUSIONS

The large increases in expected volumes of ALIF and PLF could necessitate training of more spinal surgeons and an examination of projected costs. Further analyses are needed to characterize the needs of this increasingly large population of surgical patients.

Validation of an effective implantable pump-infusion system for chronic convection-enhanced delivery of intracerebral topotecan in a large animal model

OBJECTIVE

Intracerebral convection-enhanced delivery (CED) has been limited to short durations due to a reliance on externalized catheters. Preclinical studies investigating topotecan (TPT) CED for glioma have suggested that prolonged infusion improves survival. Internalized pump-catheter systems may facilitate chronic infusion. The authors describe the safety and utility of long-term TPT CED in a porcine model and correlation of drug distribution through coinfusion of gadolinium.

METHODS

Fully internalized CED pump-catheter systems were implanted in 12 pigs. Infusion algorithms featuring variable infusion schedules, flow rates, and concentrations of a mixture of TPT and gadolinium were characterized over increasing intervals from 4 to 32 days. Therapy distribution was measured using gadolinium signal on MRI as a surrogate. A 9-point neurobehavioral scale (NBS) was used to identify side effects.

RESULTS

All animals tolerated infusion without serious adverse events. The average NBS score was 8.99. The average maximum volume of distribution (Vdmax) in chronically infused animals was 11.30 mL and represented 32.73% of the ipsilateral cerebral hemispheric volume. Vdmax was achieved early during infusions and remained relatively stable despite a slight decline as the infusion reached steady state. Novel tissue TPT concentrations measured by liquid chromatography mass spectroscopy correlated with gadolinium signal intensity on MRI (p = 0.0078).

CONCLUSIONS

Prolonged TPT-gadolinium CED via an internalized system is safe and well tolerated and can achieve a large Vdmax, as well as maintain a stable Vd for up to 32 days. Gadolinium provides an identifiable surrogate for measuring drug distribution. Extended CED is potentially a broadly applicable and safe therapeutic option in select patients.

Effect of Psychiatric Comorbidities on In-Hospital Outcomes and Cost for Cervical Spondylotic Myelopathy

OBJECTIVE

The present study examined the differences in outcomes of cervical spinal surgery for patients with and without a major psychiatric comorbidity using the Healthcare Cost and Utilization Project National Inpatient Sample database.

METHODS

Data were queried from the Healthcare Cost and Utilization Project National Inpatient Sample database from 2013 to 2014 for hospitalizations with a major psychiatric comorbidity and a diagnosis of cervical spondylotic myelopathy treated by an appropriate surgical procedure. The included psychiatric comorbidities were schizophrenia, episodic mood disorders (bipolar I and II disorders), delusional disorders, and psychoses not otherwise specified. Univariate and multivariate regression analyses were performed to determine the differences in outcomes between patients with and without a major psychiatric comorbidity.

RESULTS

A total of 18,335 hospitalizations met the inclusion criteria, of which 648 (3.5%) included a major psychiatric comorbidity. Multivariate regression analysis demonstrated that psychiatric comorbidity was an independent predictor of non-home discharge (odds ratio [OR], 1.81; 95% confidence interval [CI], 1.43-2.30; P < 0.0001) and a longer hospital stay (+0.52 day; 95% CI, 0.43-0.61; P < 0.0001) but was not an independent predictor of overall complications (OR, 0.79; 95% CI, 0.58-1.07; P = 0.13) or total hospital charges ($1992; 95% CI, -$917-$4902; P = 0.18).

CONCLUSIONS

Psychiatric comorbidity was associated with an increased risk of non-home discharge and a longer length of stay for patients undergoing surgical intervention for cervical myelopathy. However, we did not find an associated increased risk of in-hospital mortality, complications, or total hospital charges. Psychiatric comorbidity should not be weighed against patients who require surgical treatment for cervical spondylotic myelopathy, and special attention should be given to postoperative care and discharge planning for this unique patient population.

Aneurysmal Subarachnoid Hemorrhage with Spinal Subdural Hematoma: A Case Report and Systematic Review of the Literature

OBJECTIVE

Spinal subdural hematoma (S-SDH) rarely occurs after aneurysmal subarachnoid hemorrhage (SAH). Little information is known regarding the management and prognosis of patients with both S-SDH and SAH. Here, we present an illustrative case and provide a systematic review of S-SDH in the setting of SAH.

METHODS

A systematic literature review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines revealed 11 previous cases of concurrent intracranial SAH and spinal SDH, which are presented with our new reported case.

RESULTS

Intracranial sources of spontaneous SAH included 8 aneurysms, 1 pseudoaneurysm, and 3 angiogram-negative cases. Hunt Hess grades ranged from 1 to 4, mean time between SAH and S-SDH was 5.8 days, and S-SDH presented most frequently in the lumbar spine. Eight patients showed significant to complete clinical recovery, 2 had continued plegia of the lower extremities, and 2 expired. Modified Rankin scores (mRS) ranged from 0 to 6, with mRS >2 for 4 of 12 patients. Patients with a poor clinical outcome (mRS >2) had an initially negative cerebral angiogram, earlier presentation with less time between SAH and S-SDH (0.8 vs. 7.6 days), use of antithrombotic medication, no diversion of cerebrospinal fluid, and cervical or thoracic S-SDH.

CONCLUSION

S-SDH is uncommon in the setting of aneurysmal SAH; better outcomes are associated with lumbar location, delayed presentation, cerebrospinal fluid diversion, and lack of antithrombotic use. Conservative treatment may be sufficient in patients with delayed S-SDH and lack of significant neurologic deficits. More reported cases will allow greater understanding of this clinical entity.

Frailty status as a predictor of 3-month cognitive and functional recovery following spinal surgery: a prospective pilot study

BACKGROUND CONTEXT

As increasing numbers of elderly Americans undergo spinal surgery, it is important to identify which patients are at highest risk for poor cognitive and functional recovery. Frailty is a geriatric syndrome that has been closely linked to poor outcomes, and short-form screening may be a helpful tool for preoperative identification of at-risk patients.

PURPOSE

This study aimed to conduct a pilot study on the usefulness of a short-form screening tool to identify elderly patients at increased risk for prolonged cognitive and functional recovery following elective spine surgery.

STUDY DESIGN/SETTING

This is a prospective, comparative cohort study.

PATIENT SAMPLE

The sample comprised 100 patients over age 65 who underwent elective spinal surgery (cervical or lumbar) at a single, large academic medical center from 2013 to 2014.

OUTCOME MEASURES

Fatigue, Resistance, Ambulation, Illnesses, Loss of Weight (FRAIL) scale, Postoperative Quality of Recovery Scale (PQRS), and instrumental activities of daily living (IADL) scores were the outcome measures.

METHODS

Included patients were assessed with the FRAIL scale and stratified as robust, pre-frail, or frail. The PQRS and IADL scores were also obtained. Patients were re-examined at 1 day, 3 days, 1 month, and 3 months after surgery for cognitive recovery at 3 months, and secondarily, functional recovery at 3 months.

RESULTS

At 3 months, only 50% of frail patients had recovered to their cognitive baseline compared with 60.7% of pre-frail and 69.2% of robust patients (trend). At 3 months, 66.7% of frail patients had recovered to their functional baseline compared with 57% of pre-frail and 76.9% of robust patients (trend). Using multivariate regression modeling, at 3 months, frail patients were less likely to have recovered to their cognitive baseline compared with pre-frail and robust patients (odds ratio 0.39, confidence interval 0.131-1.161).

CONCLUSIONS

This pilot study demonstrates a trend toward poorer cognitive recovery 3 months following elective spinal surgery for frail patients. Frailty screening can help preoperatively identify patients who may experience protracted cognitive and functional recovery.

Deep brain stimulation of the ventralis intermedius nucleus for the treatment of essential tremor

A 59-year-old woman with a 30-year history of essential tremor refractory to medical therapy underwent staged deep brain stimulation of the ventralis intermedius nucleus of the thalamus (VIM). Left-sided lead placement was performed first. Once in the operating room, microelectrode recording (MER) was performed to confirm the appropriate trajectory and identify the VIM border with the ventralis caudalis nucleus. MER was repeated after repositioning 2 mm anteriorly to reduce the likelihood of stimulation-induced paresthesias. Physical examination prior to permanent lead placement demonstrated micro-lesion effect, suggesting optimal trajectory. After implantation of the permanent lead, physical examination showed excellent results. The video can be found here: https://youtu.be/nn3KRdmRCZ4 .

Association of a Distal Intradural-Extracranial Posterior Inferior Cerebellar Artery Aneurysm With Chiari Type I Malformation

BACKGROUND AND IMPORTANCE:

Distal extracranial posterior inferior cerebellar artery (PICA) aneurysms are very rare lesions and have not been previously reported in association with a Chiari type I malformation (CMI).

CLINICAL PRESENTATION:

A 56-year-old woman with a distal, low-lying, intradural-extracranial PICA aneurysm presented with a subarachnoid hemorrhage and was treated with coil embolization. The patient presented again 1 month later with symptoms of a CMI and was found to have tonsillar herniation and a large syrinx that appeared to be exacerbated by the coil mass. The patient was re-treated with a suboccipital craniectomy, C1-2 laminectomy, aneurysm trapping and excision, end-to-end PICA anastomosis, and expansile duraplasty.

CONCLUSION:

Although just a single case, important teaching points regarding the angiographic appearance of a CMI and treatment options for distal PICA aneurysms that are situated below the foramen magnum can be learned. A low-lying caudal PICA loop should trigger a workup for a CMI. Caution should be taken when using coil embolization for aneurysms in the high cervical spinal canal. Bypass with aneurysm trapping and excision may be a superior treatment option in these cases because the posterior fossa and high cervical canal can be concomitantly decompressed. To our knowledge, this is the only case reported of a distal intradural-extracranial PICA aneurysm associated with a CMI.

Primitive neuroectodermal tumors of the spine: a comprehensive review with illustrative clinical cases

Primary spinal primitive neuroectodermal tumors (PNETs) are uncommon malignancies that are increasingly reported in the literature. Spinal PNETs, like their cranial counterparts, are aggressive tumors and patients with these tumors typically have short survival times despite maximal surgery, chemotherapy, and radiation. Because no standard management guidelines exist for treating these tumors, a multitude of therapeutic strategies have been employed with varying success. In this study the authors perform a comprehensive review of the literature on primary spinal PNETs and provide 2 new cases that highlight the salient features of their clinical management.