Do robot-related complications influence 1 year reoperations and other clinical outcomes after robot-assisted lumbar arthrodesis? A multicenter assessment of 320 patients.

BACKGROUND: Robot-assisted platforms in spine surgery have rapidly developed into an attractive technology for both the surgeon and patient. Although current literature is promising, more clinical data is needed. The purpose of this paper is to determine the effect of robot-related complications on clinical outcomes METHODS: This multicenter study included adult (≥18 years old) patients who underwent robot-assisted lumbar fusion surgery from 2012-2019. The minimum follow-up was 1 year after surgery. Both bivariate and multivariate analyses were performed to determine if robot-related factors were associated with reoperation within 1 year after primary surgery. RESULTS: A total of 320 patients were included in this study. The mean (standard deviation) Charlson Comorbidity Index was 1.2 (1.2) and 52.5% of patients were female. Intraoperative robot complications occurred in 3.4% of patients and included intraoperative exchange of screw (0.9%), robot abandonment (2.5%), and return to the operating room for screw exchange (1.3%). The 1-year reoperation rate was 4.4%. Robot factors, including robot time per screw, open vs. percutaneous, and robot system, were not statistically different between those who required revision surgery and those who did not (P>0.05). Patients with robot complications were more likely to have prolonged length of hospital stay and blood transfusion, but were not at higher risk for 1-year reoperations. The most common reasons for reoperation were wound complications (2.2%) and persistent symptoms due to inadequate decompression (1.5%). In the multivariate analysis, robot related factors and complications were not independent risk factors for 1-year reoperations. CONCLUSION: This is the largest multicenter study to focus on robot-assisted lumbar fusion outcomes. Our findings demonstrate that 1-year reoperation rates are low and do not appear to be influenced by robot-related factors and complications; however, robot-related complications may increase the risk for greater blood loss requiring a blood transfusion and longer length of stay.

State of the Union in Open Neurovascular Training.

BACKGROUND: The evolution of minimally invasive endovascular approaches and training paradigms has reduced open neurovascular case exposure for neurosurgical residents. There are no published estimates of open neurovascular case volumes during residency or Committee on Advanced Subspecialty Training (CAST) accredited fellowships. METHODS: Case volumes from residency programs submitting data for CAST accredited fellowship applications were collected and analyzed. The study period covered the academic years of 2013-2016. Case index volumes were calculated to provide an estimate of total volume of cases each trainee participated in a given year. The case index volume was defined as the total volume of cases per year divided by the total training complement. RESULTS: Over the study period, institutional data from 46 programs were available. Of those programs, 9 programs had CAST accredited open cerebrovascular fellowships. Across all 46 programs, the median number of vascular cases was 246 (interquartile range [IQR]: 148-340), whereas the median number of open vascular cases was 105 (IQR: 67-152). The median number of open aneurysm cases among programs with CAST cerebrovascular fellowships was 80 (IQR: 54-103) and among programs without CAST cerebrovascular fellowships was 34 (IQR: 24-63). The median open aneurysm case index volume for trainees at programs with and without CAST cerebrovascular fellowships was 23 (IQR: 14-29) and 19 (IQR: 11-24). CONCLUSIONS: Strong neurovascular training can be obtained through dedication and planning. Completion of a CAST accredited cerebrovascular fellowship will often more than double aneurysm case exposure of trainees.

Early Readmission After Ventricular Shunting in Adults with Hydrocephalus: A Nationwide Readmission Database Analysis.

BACKGROUND: Ventricular shunting is one of the primary modalities for addressing hydrocephalus in both children and adults. Despite advances in shunt technology and surgical practices, shunt failure is a persistent challenge for neurosurgeons, and shunt revisions account for a substantial proportion of all shunt-related procedures. There are a wealth of studies elucidating failure patterns and patient demographics in pediatric cohorts; however, data in adults are less uniform. We sought to determine the rates of all-cause and shunt failure readmission in adults who underwent the insertion of a ventricular shunt. METHODS: We queried the Nationwide Readmissions Database from 2010 to 2014 to evaluate new ventricular shunts placed in adults with hydrocephalus. We sought to determine the rates of all-cause and shunt revision-related readmissions and to characterize factors associated with readmissions. We analyzed predictors including patient demographics, hospital characteristics, shunt type, and hydrocephalus cause. RESULTS: Analysis included 24,492 initial admissions for shunt placement in patients with hydrocephalus. Of patients, 9.17% required a shunt revision within the first 6 months; half of all revisions occurred within the first 41 days. There were 4044 (16.50%) 30-day and 5758 (28.8%) 90-day all-cause readmissions. In multivariable analysis, patients with a ventriculopleural shunt, Medicare insurance, and younger age had increased likelihood for shunt revision. Notable predictors for all-cause readmission were insurance type, length of hospitalization, age, comorbidities, and hydrocephalus cause. CONCLUSIONS: Most shunt revisions occurred during the first 2 months. Readmissions occurred frequently. We identified patient factors that were associated with all-cause and shunt failure readmissions.

Costs and training results of an objectively validated cadaveric perfusion-based internal carotid artery injury simulation during endoscopic skull base surgery.

BACKGROUND: Internal carotid artery injury (ICAI) is a rare, life-threatening complication of endoscopic endonasal approaches (EEAs). High-fidelity simulation methods exist, but optimization of the training cohort, training paradigm, and costs of simulation training remain unknown. METHODS: Using our previously validated, high-fidelity, perfused-cadaver model, participants attempted to manage a simulated ICAI. After a brief instructional video and coaching, the simulation was repeated. Training success was defined as successful ICAI control on the second attempt after failure on the initial attempt. Marginal costs were measured. RESULTS: Seventy-two surgeons participated in the standardized simulation, which lasted ≤15 minutes. The marginal cost of simulation was $275.00 per surgeon. A total of 44.4% (n = 32) succeeded on the first attempt before training (previously proficient); 44.4% (n = 32) failed the first attempt, but succeeded after training (training successes); and 11.1% (n = 8) failed both attempts. The cost per training success was $618.75. Forty-two surgeons had never treated an ICAI, with 24 becoming training successes (57.1% overall, 82.8% when excluding previously proficient surgeons). Twenty-nine had experienced a real or simulated ICAI, with 8 (27.6% overall, 72.7% excluding previously proficient surgeons) becoming training successes. The cost per training success was lowest in the ICAI-naive group ($481.25) and highest among surgeons with simulated and real ICAI experience ($1650). CONCLUSIONS: Surgeons can be trained to manage ICAI in a single, brief, low-cost session. Although all groups improved, training an ICAI-naive or resident cohort may maximize training results. A perfused-cadaver model is a reproducible, realistic, and low-cost method for training surgeons to manage life-threatening ICAI during an EEA.

Increased Hospital Surgical Volume Reduces Rate of 30- and 90-Day Readmission After Acoustic Neuroma Surgery.

BACKGROUND: Hospital readmissions are commonly linked to elevated health care costs, with significant financial incentive introduced by the Affordable Care Act to reduce readmissions. OBJECTIVE: To study the association between patient, hospital, and payer factors with national rate of readmission in acoustic neuroma surgery. METHODS: All adult inpatients undergoing surgery for acoustic neuroma in the newly introduced Nationwide Readmissions Database from 2013 to 2014 were included. We identified readmissions for any cause with a primary diagnosis of neurological, surgical, or systemic complication within 30- and 90-d after undergoing acoustic neuroma surgery. Multivariable models were employed to identify patient, hospital, and administrative factors associated with readmission. Hospital volume was measured as the number of cases per year. RESULTS: We included patients representing a weighted estimate of 4890 admissions for acoustic neuroma surgery in 2013 and 2014, with 355 30-d (7.7%) and 341 90-d (9.1%) readmissions. After controlling for patient, hospital, and payer factors, procedural volume was significantly associated with 30-d readmission rate (OR [odds ratio] 0.992, p = 0.03), and 90-d readmission rate (OR 0.994, p = 0.047). The most common diagnoses during readmission in both 30- and 90-d cohorts included general central nervous system complications/deficits, hydrocephalus, infection, and leakage of cerebrospinal fluid (rhinorrhea/otorrhea). CONCLUSION: After controlling for patient, hospital, and payer factors, increased procedural volume is associated with decreased 30- and 90-d readmission rate for acoustic neuroma surgery. Future studies seeking to improve outcomes and reduce cost in acoustic neuroma surgery may seek to further evaluate the role of hospital procedural volume and experience.

Treatment at Safety-Net Hospitals Is Associated with Delays in Coil Embolization in Patients with Subarachnoid Hemorrhage.

BACKGROUND: Successful endovascular management of aneurysmal subarachnoid hemorrhage (aSAH) requires timely access to substantial resources. Prior studies suggest an association between time to treatment and patient outcome. Patients treated at safety-net hospitals are thought to be particularly vulnerable to disparities in access to interventions that require substantial technologic resources. We hypothesized that patients with aSAH treated at safety-net hospitals are at greater risk for delayed access to endovascular treatment. METHODS: Adults undergoing endovascular coiling procedures between 2002 and 2011 in the Nationwide Inpatient Sample were included. Hospitals in the quartile with the highest proportion of Medicaid or uninsured patients were defined as safety-net hospitals. A multivariate model including patient-level and hospital-level factors was constructed to permit analysis of delays in endovascular treatment (defined as time to treatment >3 days). RESULTS: Analysis included 7109 discharges of patients with aSAH undergoing endovascular coil embolization procedures from 2002 to 2011. Median time to coil embolization in all patients was 1 day; 10.1% of patients waited >3 days until treatment. In multivariate analysis, patients treated at safety-net hospitals were more likely to have a prolonged time to coil embolization (odds ratio = 1.32, P < 0.01) compared with patients treated at low-burden hospitals. CONCLUSIONS: After controlling for patient and hospital factors, individuals with aSAH treated at safety-net hospitals from 2002 to 2011 were more likely to have a delay to endovascular coil embolization than individuals treated at non-safety-net hospitals. This disparity could affect patient outcomes.

Predictors of Surgical Site Infection After Nonemergent Craniotomy: A Nationwide Readmission Database Analysis.

OBJECTIVE: Surgical site infections (SSIs) carry significant patient morbidity and mortality and are a major source of readmissions after craniotomy. Because of their deleterious effects on health care outcomes and costs, identifying modifiable risk factors holds tremendous value. However, because SSIs after craniotomy are rare and most existing data comprise single-institution studies with small sample sizes, many are likely underpowered to discern for such factors. The objective of this study was to use a large hetereogenous patient sample to determine SSI incidence after nonemergent craniotomy and identify factors associated with readmission and subsequent need for wound washout. METHODS: We used the 2010-2014 Nationwide Readmissions Database cohorts to discern for factors predictive of SSI and washout. RESULTS: We identified 93,920 nonemergent craniotomies. There were 2079 cases of SSI (2.2%) and 835 reoperations for washout (0.89%) within 30 days of index admission and there were 2761 cases of SSI (3.6%) and 1220 reoperations for washout (1.58%) within 90 days. Several factors were predictive of SSI in multivariate analysis, including tumor operations, external ventricular drain (EVD), age, length of stay, diabetes, discharge to an intermediate-care facility, insurance type, and hospital bed size. Many of these factors were similarly implicated in reoperation for washout. CONCLUSIONS: SSI incidence in neurosurgery is low and most readmissions occur within 30 days. Several factors predicted SSI after craniotomy, including operations for tumor, younger age, hospitalization length, diabetes, discharge to institutional care, larger hospital bed size, Medicaid insurance, and presence of an EVD. Diabetes and EVD placement may represent modifiable factors that could be explored in subsequent prospective studies for their associations with cranial SSIs.

Predictors of 30- and 90-day readmission following craniotomy for malignant brain tumors: analysis of nationwide data.

Hospital readmissions are a major contributor to increased health care costs and are associated with worse patient outcomes after neurosurgery. We used the newly released Nationwide Readmissions Database (NRD) to describe the association between patient, hospital and payer factors with 30- and 90-day readmission following craniotomy for malignant brain tumor. All adult inpatients undergoing craniotomy for primary and secondary malignant brain tumors in the NRD from 2013 to 2014 were included. We identified all cause readmissions within 30- and 90-days following craniotomy for tumor, excluding scheduled chemotherapeutic procedures. We used univariate and multivariate models to identify patient, hospital and administrative factors associated with readmission. We identified 27,717 admissions for brain tumor craniotomy in 2013-2014, with 3343 (13.2%) 30-day and 5271 (25.7%) 90-day readmissions. In multivariate analysis, patients with Medicaid and Medicare were more likely to be readmitted at 30- and 90-days compared to privately insured patients. Patients with two or more comorbidities were more likely to be readmitted at 30- and 90-days, and patients discharged to skilled nursing facilities or home health care were associated with increased 90-day readmission rates. Finally, hospital procedural volume above the 75th percentile was associated with decreased 90-day readmission rates. Patients treated at high volume hospitals are less likely to be readmitted at 90-days. Insurance type, non-routine discharge and patient comorbidities are predictors of postoperative non-scheduled readmission. Further studies may elucidate potentially modifiable risk factors when attempting to improve outcomes and reduce cost associated with brain tumor surgery.

Bone flap perfusion assessment using near-infrared fluorescence imaging.

BACKGROUND: Microsurgical vascularized bone flaps are a versatile technique for reconstructing large bone defects. However, the assessment of perfusion is challenging, because clinical examination is difficult intraoperatively and often not possible postoperatively. Therefore, it is important to develop techniques to assess the perfusion of vascularized bone flaps and potentially improve the surgical outcomes. Near-infrared (NIR) fluorescence imaging has previously been shown to provide real-time, intraoperative evaluation of vascular perfusion. The present pilot study investigated the ability of NIR imaging to assess the perfusion of vascularized bone flaps. METHODS: Vascularized bone flaps were created in female Yorkshire pigs using well-established models for porcine forelimb osteomyocutaneous flap allotransplantation (n = 8) and hindlimb fibula flaps (n = 8). Imaging of the bone flaps was performed during harvest using the FLARE intraoperative fluorescence imaging system after systemic injection of indocyanine green. Perfusion was also assessed using the standard of care by clinical observation and Doppler ultrasonography. NIR fluorescence perfusion assessment was confirmed by intermittent clamping of the vascular pedicle. RESULTS: NIR fluorescence imaging could identify bone perfusion at the cut end of the osteotomy site. When the vascular pedicle was clamped or ligated, NIR imaging demonstrated no fluorescence when injected with indocyanine green. With clamp removal, the osteotomy site emitted fluorescence, indicating bone perfusion. The results using fluorescence imaging showed 100% agreement with the clinical observation and Doppler findings. CONCLUSIONS: Vascularized bone transfers have become an important tool in reconstructive surgery; however, no established techniques are available to adequately assess perfusion. The results of our pilot study have indicated that NIR imaging can provide real-time, intraoperative assessment of bone perfusion.

Face transplant perfusion assessment using near-infrared fluorescence imaging.

BACKGROUND: Composite tissue allografts (CTAs) including partial face transplantation have been achieved clinically. However, risks of complications including tissue ischemia, rejection, and transplant failure are significant. Safe and effective techniques to assess perfusion are needed to decrease complications in composite tissue flaps. Near-infrared (NIR) fluorescence imaging has been previously shown to provide a real-time, intraoperative evaluation of perfusion. This study investigates the use of NIR imaging in partial face CTA harvest. METHODS: We created hemifacial CTAs (n = 8) using an established porcine model. This included ear cartilage, nerve, lymphoid tissue, muscle, and skin with perfusion by the carotid artery and external jugular vein. We injected animals systemically with indocyanine green and obtained NIR fluorescence images simultaneously with color video. In addition, we assessed the elevated hemifacial flaps using standard of care (i.e., clinical examination and Doppler). RESULTS: Flap design was facilitated by NIR imaging with localization of perforators to the hemifacial CTA flap. In particular, an arterial and venous phase could be clearly identified. We assessed perfusion of the flap by NIR fluorescence intensity after injection of indocyanine green. Sequential clamping of the artery and vein confirmed correlation of perfusion deficits with NIR imaging as well as with clinical examination and Doppler. CONCLUSIONS: Evaluation and assessment of perfusion are important in facial transplantation. The results from our pilot study indicate that NIR imaging has the capability to assess perfusion of partial facial CTAs. This emergent technology shows promise in assessing tissue perfusion in a composite flap.