Retrospective analysis of national insurance billing database. To examine trends in reoperation after single-level lumbar discectomy. Lumbar discectomy is the most commonly performed procedure for treatment of radiculopathy caused by disc herniation. Randomized clinical trials have demonstrated the advantage of discectomy over nonsurgical treatment options, allowing for a more rapid reduction in symptoms. However, population-level data regarding reoperation after single level discectomy is limited. Data were collected using the commercially available PearlDiver software for patients billed with the Current Procedural Terminology code for our index procedure, hemilaminotomy and removal of disc material, between January 2007 and September 2014. The index group was then followed for up to 4 years for recurrent lumbar surgery, including spinal fusion, laminectomy, and additional discectomy. Analysis of data obtained from 13,654 patient records revealed a rate of additional lumbar surgeries after single-level discectomy of 3.95% (539/13654) within 3 months and 12.2% (766/6274) within 4 years of the index procedure. Lumbar spinal fusion was performed on 5.9% (370/6274) of patients within 4 years. Patients who received a re-exploration discectomy within 2 years of the index procedure went on to receive lumbar fusion at a rate of 38.4% (48/125) within the 4 years after the re-exploration discectomy. The average additional cost of lumbar reoperation, as measured by insurance reimbursement, was approximately $11,161 per-patient per year. We report an overall 4-year reoperation rate of 12.2% after single-level discectomy. In addition, we report a rate of progression to lumbar fusion following re-exploration discectomy of 38.4% within 4 years of reoperation. Further studies are needed regarding the best treatment algorithm in patients with reherniation or iatrogenic instability after lumbar discectomy. This study should enhance the shared decision making process by providing surgeons and patients with valuable data regarding the frequency and nature of reoperations after discectomy. Level of Evidence: 3

INTRODUCTION: Angioembolization (AE) is widely used for hemorrhagic control in patients with pelvic fracture. The latest version of the Resources for Optimal Care of the Injured Patient issued by the American College of Surgeons Committee on Trauma requires interventional radiologists to be available within 30 minutes to perform an emergency AE. However, the impact of time-to-AE on patient outcomes remains unknown. We hypothesized that a longer time-to-AE would be significantly associated with increased mortality in patients with pelvic fracture. METHODS: This is a 2-year retrospective cohort study using the American College of Surgeons Trauma Quality Improvement Program database from January 2013 to December 2014. We included adult patients (age ≥ 18 years) with blunt pelvic fracture who underwent pelvic AE within 4 hours of hospital admission. Patients who required any hemorrhage control surgery for associated injuries within 4 hours were excluded. Hierarchical logistic regression was performed to evaluate the impact of time-to-AE on in-hospital and 24-hour mortality. RESULTS: A total of 181 patients were included for analysis. The median age was 54 years (interquartile range, 38–68) and 69.6% were male. The median injury severity score was 34 (interquartile range, 27–43). Overall in-hospital mortality rate was 21.0%. The median packed red blood cell transfusions within 4 and 24 hours after admission were 4 and 6 units, respectively. After adjusting for other covariates in a hierarchical logistic regression model, a longer time-to-pelvic AE was significantly associated with increased in-hospital mortality (odds ratio, 1.79 for each hour; 95% confidence interval, 1.11–2.91; p = 0.018). CONCLUSION: The current study showed an increased risk of in-hospital mortality related to a prolonged time-to-AE for hemorrhagic control following pelvic fractures. Our results suggest that all trauma centers should allocate resources to minimize delays in performing pelvic AE. LEVEL OF EVIDENCE: Therapeutic/care management, level IV.

After creation of a new arteriovenous fistula (AVF), assessment of readiness for use is an important clinical task. Accurate prediction of successful use is challenging, and augmentation of the physical exam with ultrasound has become routine. Herein, we propose a point-of-care tool based on machine learning to enhance prediction of successful unassisted radiocephalic arteriovenous fistula (AVF) use. Our analysis includes pooled patient-level data from 704 patients undergoing new radiocephalic AVF creation, eligible for hemodialysis, and enrolled in the 2014–2019 international multicenter PATENCY-1 or PATENCY-2 randomized controlled trials. The primary outcome being predicted is successful unassisted AVF use within 1-year, defined as 2-needle cannulation for hemodialysis for ≥90 days without preceding intervention. Logistic, penalized logistic (lasso and elastic net), decision tree, random forest, and boosted tree classification models were built with a training, tuning, and testing paradigm using a combination of baseline clinical characteristics and 4–6 week ultrasound parameters. Performance assessment includes receiver operating characteristic curves, precision-recall curves, calibration plots, and decision curves. All modeling approaches except the decision tree have similar discrimination performance and comparable net-benefit (area under the ROC curve 0.78–0.81, accuracy 69.1–73.6%). Model performance is superior to Kidney Disease Outcome Quality Initiative and University of Alabama at Birmingham ultrasound threshold criteria. The lasso model is presented as the final model due to its parsimony, retaining only 3 covariates: larger outflow vein diameter, higher flow volume, and absence of >50% luminal stenosis. A point-of-care online calculator is deployed to facilitate AVF assessment in the clinic.

Study Design: This was a retrospective database study. Objective: The aim of this study was to use a large sample to accurately determine risk factors and rates of neurological complications in patients undergoing commonly performed lumbar spine surgeries. Summary of Background Data: Damage to neurological structures and failed back surgery syndrome (FBSS) are among the most feared complications of lumbar spine surgery. Despite the large impact on quality of life these complications have, reported rates of neurological complications vary immensely, ranging from 0.46% to 24%. Materials and Methods: Data were obtained for patients undergoing initial posterior lumbar interbody fusion, transforaminal lumbar interbody fusion, anterior lumbar interbody fusion, posterolateral fusion, discectomy, and laminectomy procedures from January 2007 to June 2015 covered by the nationwide insurance carrier Humana. Patient records were analyzed to determine rates of dural tear, damage to nervous tissue, cauda equina syndrome, neurogenic bowel/bladder, and FBSS following each procedure. Rates were determined for patients undergoing single/multilevel procedures, by age, and for patients with a previous diagnosis of depression to determine the influence these factors had on the risk of neurologic complications. Results: Analysis of 70,581 patient records revealed a dural tear rate of 2.87%, damage to the nervous tissue of 1.47%, cauda equina syndrome of 0.75%, neurogenic bowel or bladder of 0.45%, and FBSS of 15.05% following lumbar spine surgery. The incidence of complications was highest for patients undergoing multilevel procedures and posterior fusion. Depression was a significant risk factor for FBSS (risk ratio, 1.74; P<0.0001), damage to nervous tissue (1.41; P<0.0001), and dural tear (1.15; P<0.0001), but had no impact on risk of cauda equina syndrome or neurogenic bowel or bladder. Increased age was associated with higher rates of dural tear and damage to nervous tissue. Conclusions: Patients with a history of depression are at significantly increased risk for neurologic complications following lumbar spine surgery and should be managed accordingly.