Leveraging machine learning to develop a postoperative predictive model for postoperative urinary retention following lumbar spine surgery.

Introduction: Postoperative urinary retention (POUR) is the inability to urinate after a surgical procedure despite having a full bladder. It is a common complication following lumbar spine surgery which has been extensively linked to increased patient morbidity and hospital costs. This study hopes to development and validate a predictive model for POUR following lumbar spine surgery using patient demographics, surgical and anesthesia variables. Methods: This is a retrospective observational cohort study of 903 patients who underwent lumbar spine surgery over the period of June 2017 to June 2019 in a tertiary academic medical center. Four hundred and nineteen variables were collected including patient demographics, ICD-10 codes, and intraoperative factors. Least absolute shrinkage and selection operation (LASSO) regression and logistic regression models were compared. A decision tree model was fitted to the optimal model to classify each patient's risk of developing POUR as high, intermediate, or low risk. Predictive performance of POUR was assessed by area under the receiver operating characteristic curve (AUC-ROC). Results: 903 patients were included with average age 60 ± 15 years, body mass index of 30.5 ± 6.4 kg/m2, 476 (53%) male, 785 (87%) white, 446 (49%) involving fusions, with average 2.1 ± 2.0 levels. The incidence of POUR was 235 (26%) with 63 (7%) requiring indwelling catheter placement. A decision tree was constructed with an accuracy of 87.8%. Conclusion: We present a highly accurate and easy to implement decision tree model which predicts POUR following lumbar spine surgery using preoperative and intraoperative variables.

Risk factors for postoperative urinary retention after deep brain stimulation surgery: the role of the subthalamic nucleus.

OBJECTIVE: Deep brain stimulation (DBS) is a common procedure in neurosurgery used for the treatment of Parkinson's disease (PD) and essential tremor (ET) among other disorders. Lower urinary tract dysfunction is a common complication in PD, and this study aimed to evaluate the risk factors of postoperative urinary retention (POUR) after DBS surgery in patients with PD compared with patients with ET. Understanding the risk factors associated with this complication may help in the development of strategies to minimize its occurrence and improve patient outcomes. METHODS: The study was a retrospective analysis of patients who underwent DBS surgery for PD and ET at the University of Florida between 2010 and 2021. The surgical technique used has been described in previous articles and included a two-stage procedure, with stage 1 involving burr hole placement, microelectrode recording, and electrode implantation and stage 2 involving the placement of an implantable pulse generator (IPG). Data were collected on patient characteristics and surgical details and analyzed using univariate and mixed-linear models. Post hoc propensity score matching was used to confirm the association between subthalamic nucleus (STN)-DBS and POUR. RESULTS: The study included 350 patients (153 with PD and 197 with ET) who underwent 1086 DBS surgeries (lead implantations, IPG placement, and IPG replacements). The POUR rates were 16.6% (79/477), 5.2% (19/363), and 0.4% (1/246) for stage 1, stage 2, and IPG replacement procedures, respectively. Optimal mixed-effects logistic modeling revealed history of urinary retention (OR 9.3, p = 0.004), male sex (OR 2.7, p = 0.011), having an electrode placed or connected for the first time (OR 2.2, p = 0.014), anesthesia time (OR 1.5 for each 30-minute increase, p < 0.0001), preoperative opioid use (OR 1.4 for each additional 10 morphine milligram equivalents, p = 0.032), and Charlson Comorbidity Index (OR 1.4 per comorbidity, p = 0.017) to be significant risk factors for POUR. Having an electrode in the STN was found to be protective of POUR (propensity score-matched analysis: OR 0.2, p = 0.010). CONCLUSIONS: Most risk factors found to increase the risk of POUR in DBS are not modifiable but are still important to consider in preoperative planning. Opioid use reduction and shorter anesthesia time may be modifiable risk factors to weigh against their alternative. Targeting the STN during DBS may result in decreased rates of POUR. This highlights the potential for STN-targeted DBS in reducing POUR risk in PD and ET patients.

Automated and Optimized Neurosurgery Scheduling System Improves Resident Satisfaction.

BACKGROUND AND OBJECTIVES: Neurosurgery residency involves a complex structure with multiple hospitals, services, and clinic days, leading to challenges in creating equitable call schedules. Manually prepared scheduling systems are prone to biases, error, and perceived unfairness. To address these issues, we developed an automated scheduling system (Automated Optimization of Neurosurgery Scheduling System [AONSS]) to reduce biases, accommodate resident requests, and optimize call variation, ultimately enhancing the educational experience by promoting diverse junior-senior-attending relationships. METHODS: AONSS was developed and tailored to the University of Florida program, with inaugural use in 2021-2022 and mandatory implementation in the 2022-2023 academic year. 2019-2021 academic years were used as control. Residents were surveyed using Google Forms before and after implementation to assess its impact. Outcome measures included call and pairing variations, duty hours, as well as subjective factors such as satisfaction, fairness, and perceived biases. RESULTS: Twenty-six residents (28%-39% female/year) were included in the study. AONSS was used for 6/13 blocks during the 2021-2022 academic year and 13/13 blocks for the 2022-2023 academic year. Overall call variation reduced by 70%. All other objective secondary measures have improved with AONSS. Weekly and monthly duty hours were reduced and less varied. Satisfaction scores improved from 21% reporting being somewhat satisfied or very satisfied to 90%. Fairness scores improved from 43% reporting being somewhat fair or very fair to 95%. Perception of gender bias decreased from 29% to 0%. No resident felt there was racial bias in either system. CONCLUSION: Our newly developed automated scheduling system effectively reduces variation among calls in a complex neurosurgery residency, which, in return, was found to increase residents' satisfaction with their schedule, improve their perception of fairness with the schedule, and has completely removed the perception of sexual bias in a program that has a large percentage of females. In addition, it was found to be associated with decreased duty hours.

The effect of myelopathic symptoms on hospital costs, length of stay, and discharge location in anterior cervical discectomy and fusion.

OBJECTIVE: Cervical spondylotic myelopathy (CSM) is a common clinical degenerative disease treated with anterior cervical discectomy and fusion (ACDF), which seriously impacts quality of life and causes severe disability. The objective of the study was to determine the effect of different characteristics of the neurological deficit found in myelopathic patients undergoing ACDFs on hospital cost, length of stay (LOS), and discharge location. METHODS: This is a retrospective review of ACDF cases performed at a single institution by multiple surgeons from 2011 to 2017. Patient symptomatology, complications, comorbidities, demographics, surgical time, LOS, and discharge location were collected. Patients with readmissions or reoperations were excluded. Symptoms evaluated were based on clinical diagnosis, Japanese Orthopaedic Association classification, Ranawat grade, and Cooper scales. Symptoms were further grouped using principal component analysis. Cost was defined as surgical episode hospital stay costs plus outpatient clinic costs plus discharge disposition cost. Multivariate linear regression models were created to evaluate correlations with outcomes. The primary outcome was total 90-day hospital costs. Secondary outcomes were discharge location and LOS. RESULTS: A total of 250 patients were included in the analyses. Discharge location, neuromonitoring use, number of surgical vertebral levels, cage use, LOS, surgical time, having a complication, and sex were all found to be predictive of total 90-day costs. Myelopathic symptomatology was not found to be associated with increased 90-day costs (p ≥ 0.131) when correcting for these other factors. Lower-extremity functionality was found to be associated with increased LOS (p < 0.0001). Upper-extremity myelopathy was found to be associated with increased discharge location needs (p < 0.0001). CONCLUSIONS: Cervical myelopathy was not found to be predictive of total 90-day costs using symptomatology based on multiple myelopathy grading systems. Lower-extremity functionality was, however, found to predict LOS, while upper-extremity myelopathy was found to predict increased discharge location needs. This implies that preoperative deficits from myelopathy should not be considered in a bundled payment system; however, certain myelopathic symptoms should be considered when determining the cost of care.

Pre-operative prediction of post-operative urinary retention in lumbar surgery: a prospective validation of machine learning model.

PURPOSE: Predicting urinary retention is difficult. The aim of this study is to prospectively validate a previously developed model using machine learning techniques. METHODS: Patients were recruited from pre-operative clinic. Prediction of urinary retention was completed pre-operatively by 4 individuals and compared to ground truth POUR outcomes. Inter-rater reliability was calculated with intercorrelation coefficient (2,1). RESULTS: 171 patients were included with age 63 ± 14 years, 58.5% (100/171) male, BMI 30.4 ± 5.9 kg/m2, American Society of Anesthesiologists class 2.6 ± 0.5, 1.7 ± 1.0 levels, 56% (96/171) fusions. The observed rate of POUR was 25.7%. The model's performance was found to be 0.663 (0.567-0.759). With a regression model probability cutoff of 0.24 and a neural network cutoff of 0.23, the following predictive power was achieved: specificity 90.6%, sensitivity 22.7%, negative predictive value 77.2%, positive predictive value 45.5%, and accuracy 73.1%. Intercorrelation coefficient for the regression aspect of the model was found to be 0.889 and intercorrelation coefficient for the neural network aspect of the model was found to be 0.874. CONCLUSIONS: This prospective study confirms performance of the prediction model for POUR developed with retrospective data, showing great correlation. This supports the use of machine learning techniques in the prediction of postoperative complications such as urinary retention.

High frequency alternating current neurostimulation decreases nocifensive behavior in a disc herniation model of lumbar radiculopathy.

BACKGROUND: The purpose of this study was to evaluate if kilohertz frequency alternating current (KHFAC) stimulation of peripheral nerve could serve as a treatment for lumbar radiculopathy. Prior work shows that KHFAC stimulation can treat sciatica resulting from chronic sciatic nerve constriction. Here, we evaluate if KHFAC stimulation is also beneficial in a more physiologic model of low back pain which mimics nucleus pulposus (NP) impingement of a lumbar dorsal root ganglion (DRG). METHODS: To mimic a lumbar radiculopathy, autologous tail NP was harvested and placed upon the right L5 nerve root and DRG. During the same surgery, a cuff electrode was implanted around the sciatic nerve with wires routed to a headcap for delivery of KHFAC stimulation. Male Lewis rats (3 mo., n = 18) were separated into 3 groups: NP injury + KHFAC stimulation (n = 7), NP injury + sham cuff (n = 6), and sham injury + sham cuff (n = 5). Prior to surgery and for 2 weeks following surgery, animal tactile sensitivity, gait, and static weight bearing were evaluated. RESULTS: KHFAC stimulation of the sciatic nerve decreased behavioral evidence of pain and disability. Without KHFAC stimulation, injured animals had heightened tactile sensitivity compared to baseline (p < 0.05), with tactile allodynia reversed during KHFAC stimulation (p < 0.01). Midfoot flexion during locomotion was decreased after injury but improved with KHFAC stimulation (p < 0.05). Animals also placed more weight on their injured limb when KHFAC stimulation was applied (p < 0.05). Electrophysiology measurements at end point showed decreased, but not blocked, compound nerve action potentials with KHFAC stimulation (p < 0.05). CONCLUSIONS: KHFAC stimulation decreases hypersensitivity but does not cause additional gait compensations. This supports the idea that KHFAC stimulation applied to a peripheral nerve may be able to treat chronic pain resulting from sciatic nerve root inflammation.

Evaluation of patients referred to the spine clinic via telemedicine and the impact on diagnosis and surgical decision-making.

OBJECTIVE: Telemedicine encounters are expanding in utility for outpatient care and evaluation, partially as a necessity during the COVID-19 pandemic. It is unclear if telemedicine evaluation is comparable to in-person assessment of patients with spinal pathology undergoing surgical consultation. The objective of this study was to determine if treatment plans change for spine patients evaluated in person following an initial telemedicine consultation. METHODS: Patients referred to the authors' comprehensive spine center were evaluated first via telemedicine and then in clinic. Telemedicine evaluations were conducted via video evaluation with an attending surgeon. Demographic data including age, gender, and distance traveled from the clinic were retrospectively recorded. A chart review retrieved symptoms, radiographic details, and past medical history. The primary outcome was if the treatment plan changed (plan change [PC]) after seeing the patient in the clinic. Chi-square tests and binary logistical regression produced uni- and multivariate analyses. RESULTS: There were 152 new patients seen via telemedicine and in person. Pathology was present in the cervical (28.3%), thoracic (9.9%), and lumbar (61.8%) spine. The most common symptom was pain (72.4%), followed by radiculopathy (66.4%), weakness (26.3%), myelopathy (15.1%), and claudication (12.5%). There were 37 patients (24.3%) for whom there was a PC after clinic evaluation, and of those, only 5 (3.3%) were due to physical examination (PCPE) findings. On univariate analysis, a longer duration between telemedicine and clinic visit (odds ratio [OR] 1.094 per 7 days, p = 0.003), having pathology in the thoracic spine (OR 3.963, p = 0.018) and lack of sufficient imaging (OR 25.455, p < 0.0001) were predictive of a PC. Having pathology in the cervical spine (OR 9.538, p = 0.047) and adjacent-segment disease (OR 11.471, p = 0.010) were predictive of a PCPE. CONCLUSIONS: This study demonstrates that telemedicine may be an effective modality for the initial evaluation of spine surgical patients, without compromising decision-making in the absence of an in-person physical examination.

The Enhanced Recovery After Surgery pathway for posterior cervical surgery: a retrospective propensity-matched cohort study.

OBJECTIVE: The Enhanced Recovery After Surgery (ERAS) protocol is a comprehensive, multifaceted approach aimed at improving postoperative outcomes. It incorporates a range of strategies to promote early and more effective recovery, including reducing pain, complications, and length of stay, without increasing readmission rate. To date, ERAS for spine surgery patients has been primarily limited to lumbar surgery and anterior cervical decompression and fusion (ACDF). ERAS has not been previously studied for posterior cervical surgery, which may present a greater opportunity for improvement in patient outcomes with ERAS than ACDF. This single-institution, multi-surgeon study assessed the impact of an ERAS protocol in patients undergoing posterior cervical decompression surgery. METHODS: This study included a retrospective consecutive patient cohort with controls that were propensity matched for age, body mass index, sex, home opioid use, surgical levels, Nurick grade, and smoking status. In addition, consecutive patients who underwent posterior cervical decompression surgery for degenerative disease from December 2014 to December 2021 were included. ERAS was implemented in December 2018. Demographic, perioperative, clinical, and radiographic information was gathered. Regression models were created to evaluate length of stay, physiological function, pain levels, and opioid use. The primary focus was length of stay, with secondary outcomes including timing of ambulation, bowel movement, and voiding; daily pain scores; opioid consumption; discharge status; 30-day readmission rates; and reoperation rates. RESULTS: There were 366 patients included in the study, all of whom were included in multivariate models, and 254 (127 in each cohort) were included on the basis of matching. After propensity matching, patient characteristics, operative procedures, and operative duration were similar between groups. The ERAS cohort had a significantly improved length of stay (3.2 vs 4.7 days, p < 0.0001) and home discharge rate (80% vs 50%, p < 0.001) without an increase in readmission rate. The ERAS cohort had an earlier day of the first ambulation (p = 0.003), bowel movement (p = 0.014), and voiding (p = 0.001). ERAS demonstrated a significantly lower composite complication rate (1.1 vs 1.8, p < 0.0001). ERAS resulted in better maximum pain scores (p = 0.043) and trended toward improved mean pain scores (p = 0.072), although total opioid use was similar. CONCLUSIONS: Implementing a novel ERAS protocol significantly improved length of stay, return of physiological function, home discharge, complications, and maximum pain score after posterior cervical surgery.

Curvularia and the Brain: Case Demonstration of Optimal Management.

Background: Curvularia is a ubiquitous fungus found in tropical climates and has been reported to grow on marijuana leaves. Rarely, it can infect humans and propagate from the nasal sinuses into the brain. Case: A 28-year-old immunocompetent patient presented with history of nasal polyps, headache, and subtle visual deficits on the right. Imaging revealed what appeared to be an invasive mass growing through the ethmoid and sphenoid sinuses into the anterior cranial fossa. Results: Otolaryngology performed an endoscopic nasal biopsy with pathology and cultures consistent for Curvularia (figure 6). A combination case with neurosurgery and otolaryngology was planned. Surgeons used a bifrontal craniotomy and endonasal approach for gross total resection. Following resection, the patient was placed on 4 weeks of amphotericin treatment followed by 12 months of voriconazole based on recommendations by infectious disease. The patient has been stable since surgery. Conclusion: Curvularia is a rare but potentially life threatening central nervous system infection that can be acquired from inhalational marijuana use. This illustrative case shows the importance of aggressive debridement followed by broad spectrum antifungal treatment to optimize outcome. With marijuana's increasing popularity, Curvalaria should be included on the differential diagnosis.

The Evolution of Endovascular Therapy for Intracranial Aneurysms: Historical Perspective and Next Frontiers.

The history of cerebral aneurysm treatment has a rich and storied past with multiple notable luminaries contributing insights. The modern era has transitioned from primarily clip ligation to increasing use of endovascular therapy. Even more recently, the use of intrasaccular flow diverters has been introduced for the treatment of wide necked aneurysms. The field is continuing to transform, and bioactive coils and stents have resurfaced as promising adjuvants to promote aneurysm healing. Advanced imaging modalities are being developed that could further advance the endovascular arsenal and allow for porous memory polymer devices to enter the field. This focused review highlights notable historic contributions and advances to the point of futuristic technology that is actively being developed.

Enhanced recovery after surgery (ERAS) improves return of physiological function in frail patients undergoing one- to two-level TLIFs: an observational retrospective cohort study.

BACKGROUND CONTEXT: The enhanced recovery after surgery (ERAS) protocol is a multimodal approach which has been shown to facilitate recovery of physiological function, and reduce early post-operative pain, complications, and length of stay (LOS) in open one- to two-level TLIF. The benefit of ERAS in specifically frail patients undergoing TLIF has not been demonstrated. Frailty is clinically defined as a syndrome of physiological decline that can predispose patients undergoing surgery to poor outcomes. PURPOSE: This study primarily evaluated the benefit of an ERAS protocol in frail patients undergoing one- or two-level open TLIF compared to frail patients without ERAS. Secondarily, we assessed whether outcomes in frail patients with ERAS approximated those seen in nonfrail patients with ERAS. STUDY DESIGN: Retrospective consecutive patient cohort with controls propensity-matched for age, body mass index, sex, and smoking status. PATIENT SAMPLE: Consecutive patients that underwent one- or two-level open TLIF for degenerative disease from August, 2015 to July, 2021 by a single surgeon. ERAS was implemented in December 2018. OUTCOME MEASURES: Primary outcome measure was return of postoperative physiological function defined as the summation of first day to ambulate, first day to bowel movement, and first day to void. Additional outcome measures included LOS, daily average pain scores, opioid use, discharge disposition, 30-day readmission rate, and reoperation. METHODS: A retrospective analysis of frail patients > 65 years of age undergoing one- to two-level open TLIF post-ERAS were compared to propensity matched frail pre-ERAS patients. Frailty was assessed using the Fried phenotype classification (score >1). Patient demographics, LOS, first-day-to-ambulate (A1), first-day-to-bowel movement (B1), first-day-to-void (V1) were collected. Return of physiological function was defined as A1+B1+V1. Primary analysis was a comparison of frail patients pre-ERAS versus post-ERAS to determine effect of ERAS on return of physiologic function with frailty. Secondary analysis was a comparison of post-ERAS frail versus post-ERAS nonfrail patients to determine if return of physiologic function in frail patients with ERAS approximates that of nonfrail patients. RESULTS: In the primary analysis, 32 frail patients were included with mean age ± standard deviation of 72.8±4.4 years, mean BMI 28.8±5.5, 65.6% were male, 15 pre-ERAS and 17 post-ERAS. Patient characteristics were similar between groups. After ERAS implementation, return of physiological function improved by a mean 3.2 days overall (post-ERAS 3.4 vs. pre-ERAS 6.7 days) (p<.0001), indicating a positive effect of ERAS in frail patients. Additionally, length of stay improved by 1 day (4.8±1.6 vs. 3.8±1.9 days, p<.0001). Total daily intravenous morphine milligram equivalent (MME) as well as average daily pain scores were similar between groups. Secondarily, 26 nonfrail patients post ERAS were used as a comparison group with the 17 post-ERAS frail cohort. Mean age of this cohort was 73.4±4.6 years, mean BMI 27.4±4.9, and 61.9% were male. Return of physiologic function was similar between cohorts (post-ERAS nonfrail 3.5 vs. post-ERAS frail 3.4 days) (p=.938), indicating the benefit with ERAS in frail patients approximates that of nonfrail patients. CONCLUSIONS: ERAS significantly improves return of physiologic function and length of stay in patients with frailty after one- to two-level TLIF, and approximates improved outcomes seen in non-frail patients.

Glioma Immunotherapy: Advances and Challenges for Spinal Cord Gliomas.

Spinal cord gliomas are rare entities that often have limited surgical options. Immunotherapy has shown promise in intracranial gliomas with some research suggesting benefit for spinal cord gliomas. A focused review of immunotherapies that have been investigated in spinal cord gliomas was performed. The primary methods of immunotherapy investigated in spinal cord gliomas include immune checkpoint inhibitors, adoptive T-cell therapies, and vaccine strategies. There are innumerable challenges that must be overcome to effectively apply immunotherapeutic strategies to the spinal cord gliomas including low incidence, few antigenic targets, the blood spinal cord barrier, the immunosuppressive tumor microenvironment and neurotoxic treatment effects. Nonetheless, research has suggested ways to overcome these challenges and treatments have been effective in case reports for metastatic non-small cell lung cancer, melanoma, midline glioma and glioblastoma. Current therapies for spinal cord gliomas are markedly limited. Further research is needed to determine if the success of immunotherapy for intracranial gliomas can be effectively applied to these unique tumors.

Spinal cord injury and neurogenic lower urinary tract dysfunction: what do we know and where are we going?

One of the well reported but difficult to manage symptoms of spinal cord injury (SCI) is neurogenic lower urinary tract dysfunction (NLUTD). The type of NLUTD is variable based on location and extent of injury. SCI affects more males and NLUTD is especially debilitating for men with incomplete injury. This review summarizes the anatomical basis of NLUTD in SCI and discusses current diagnostic and management strategies that are being utilized clinically. The last two sections address new innovations and emerging discoveries with the goal of increasing scientific interest in improving treatment options for people with SCI. Areas warranting further investigation are pinpointed to address current gaps in knowledge and/or appropriate technology.

Enhanced recovery after surgery (ERAS) for open transforaminal lumbar interbody fusion: a retrospective propensity-matched cohort study.

BACKGROUND: The enhanced recovery after surgery (ERAS) protocol is a multidisciplinary, multimodal approach which has been shown to facilitate recovery of physiological function, and reduce postoperative pain, complication rates, and length of stay without adversely affecting readmission rates. Design and implementation of ERAS protocols in the recent spine surgery literature has primarily focused on patients undergoing minimally invasive lumbar surgery. However, conventional open transforaminal lumbar interbody fusion (TLIF) remains a common procedure and to date there are no studies assessing an ERAS protocol in this patient population. PURPOSE: This study presents a single surgeon experience implementing an ERAS protocol in patients undergoing 1- or 2-level open TLIF. STUDY DESIGN/SETTING: Retrospective consecutive patient cohort with controls propensity-matched for age, body mass index, sex, and smoking status. PATIENT SAMPLE: Consecutive patients that underwent 1- or 2-level open TLIF for degenerative disease from 12/2018 - 02/2021 and controls from 12/2011-12/2017 by a single surgeon. ERAS was implemented in December 2018. OUTCOME MEASURES: Primary: length of stay; Secondary: first day to ambulate, first day to bowel movement, first day to void, daily average and maximum pain scores, opioid use, discharge disposition, 30-day readmission rate, and re-operations. METHODS: Demographic, perioperative, clinical, radiographic data were collected. Multivariate mixed-linear regression models were developed for length of stay, physiological function, pain scales, and opiate use. RESULTS: There were 114 patients included with 57 in each cohort. After propensity matching, patient characteristics were similar between groups. Operative time decreased significantly after institution of ERAS (170±44 vs. 141±37 minutes, p <.0001) as did length of stay (4.6±1.7 vs. 3.6±1.6 days, p<.0001). First day of ambulation, bowel movement, and bladder voiding improved by 0.8 (p<.0001), 0.7 (p=.008), and 0.8 (p<.0001) days, respectively, in the ERAS cohort. Total daily intravenous morphine milligram equivalent (MME) (8±9 vs. 36±38, p<0.0001) and total 72-hour MME consumption (53±33 vs. 68±48, p<.0001) was significantly lower in the ERAS cohort; however, 72-hour MME consumption was not found to be significantly different in a sensitivity analysis controlling for preoperative MME. Average daily pain scores were similar between groups. CONCLUSIONS: Consistent with other studies demonstrating benefit of an ERAS protocol for minimally invasive spine procedures, ERAS was associated with decreased operative time, reduced length of stay, decrease in IV opioid consumption, and improved physiological outcomes for open 1- and 2-level TLIF. ERAS can be a potentially effective strategy for improving patient outcome and efficiency of healthcare resources for common conventional spinal surgeries such as open TLIF.

Preoperative prediction of postoperative urinary retention in lumbar surgery: a comparison of regression to multilayer neural network.

OBJECTIVE: Postoperative urinary retention (POUR) is a common complication after spine surgery and is associated with prolongation of hospital stay, increased hospital cost, increased rate of urinary tract infection, bladder overdistention, and autonomic dysregulation. POUR incidence following spine surgery ranges between 5.6% and 38%; no reliable prediction tool to identify those at higher risk is available, and that constitutes an important gap in the literature. The objective of this study was to develop and validate a preoperative risk model to predict the occurrence of POUR following routine elective spine surgery. METHODS: The authors conducted a retrospective chart review of consecutive adults who underwent lumbar spine surgery between June 1, 2017, and June 1, 2019. Patient characteristics, preexisting ICD-10 codes, preoperative pain and opioid use, preoperative alpha-1 blocker use, details of surgical planning, development of POUR, and management strategies were abstracted from electronic medical records. A binomial logistic model and a multilayer perceptron (MLP) were optimized using training and validation sets. The models' performance was then evaluated on model-naïve patients (not a part of either cohort). The models were then stacked to take advantage of each model's strengths and to avoid their weaknesses. Four additional models were developed from previously published models adjusted to include only relevant factors (i.e., factors known preoperatively and applied to the lumbar spine). RESULTS: Overall, 891 patients were included in the cohort, with a mean of 59.6 ± 15.5 years of age, 52.7% male, BMI 30.4 ± 6.4, American Society of Anesthesiologists class 2.8 ± 0.6, and a mean of 5.6 ± 5.7 comorbidities. The rate of POUR was found to be 25.9%. The two models were comparable, with an area under the curve (AUC) of 0.737 for the regression model and 0.735 for the neural network. By combining the two models, an AUC of 0.753 was achieved. With a regression model probability cutoff of 0.24 and a neural network cutoff of 0.23, maximal sensitivity and specificity were achieved, with specificity 68.2%, sensitivity 72.9%, negative predictive value 88.2%, and positive predictive value 43.4%. Both models individually outperformed previously published models (AUC 0.516-0.645) when applied to the current data set. CONCLUSIONS: This predictive model can be a powerful preoperative tool in predicting patients who will be likely to develop POUR. By using a combination of regression and neural network modeling, good sensitivity, specificity, and NPV are achieved.

Ticagrelor resistance: a case series and algorithm for management of non-responders.

The placement of cervical and intracranial stents requires the administration of antiplatelet drugs to prevent thromboembolic complications. Ticagrelor has emerged as the most widely used alternative in clopidogrel non-responders owing to its potent antiplatelet effects. Because ticagrelor does not require hepatic activation, many neurointerventionalists choose to forgo laboratory testing of platelet inhibition. In rare instances, patients may not achieve adequate platelet inhibition following ticagrelor administration. In this paper we review the mechanism of action of ticagrelor and its use in cerebrovascular procedures. We present two cases of ticagrelor non-responsiveness from two high-volume cerebrovascular centers, discuss their management, and propose an algorithm for managing ticagrelor non-responsiveness.

Chiari I malformation and Noonan's syndrome: Shared manifestations of RASopathy.

Neurologic sequalae of Noonan syndrome have been postulated in the literature. A topic of significance is the role of RASopathy in the shared pathophysiology of Noonan Syndrome and Chiari I malformation. In this unique case report, we present a patient with concomitant Noonan Syndrome and Chiari I with 4th ventricular outflow obstruction. The case highlights the importance of close clinical suspicion in this patient population. We utilize the case to delve into intricacies of the known pathophysiology and encourage ongoing investigation.

Preoperative Radiographic Prediction Tool for Early Postoperative Segmental and Lumbar Lordosis Alignment After Transforaminal Lumbar Interbody Fusion.

Objective Transforaminal lumbar interbody fusion (TLIF) is a common approach and results in varying degrees of lordosis correction. The purpose of this study is to determine preoperative radiographic spinopelvic parameters that predict change in postoperative segmental and lumbar lordosis after TLIF. Materials & Methods This study is a single surgeon retrospective review of one-level and two-level TLIFs from L3-S1. All patients underwent bilateral facetectomies, 10 mm TLIF cage (non-lordotic) insertions, and bilateral pedicle screw-rod construct placements. Pre- and post-operative X-rays were assessed for preoperative segmental lordosis (SL), lumbar lordosis (LL), and pelvic incidence (PI). Univariate and multi-predictor linear regression analyses were performed to determine the relationships between preoperative radiographic findings and change in early postoperative segmental and lumbar lordosis. Results Ninety-seven patients contributing 128 intervertebral segments were examined. The mean change in SL after TLIF was 7.3 (range: 0.10-28.9°, SD 6.39°). The mean change in LL after TLIF was 5.5˚ (range: -14.8-39.2°, standard deviation (SD) 7.16°). Greater preoperative LL predicted less postoperative LL correction, while greater preoperative PI predicted more postoperative SL and LL correction. Greater anterior disk height was noted to be associated with a decreased change in SL (∆SL). An annular tear on preoperative magnetic resonance imaging (MRI) predicted a 2.7° decrease in ∆SL. A Schmorl's node on preoperative MRI predicted a 4.0° decrease in change in LL (∆LL). Conclusions A greater preoperative lordosis and a lower spinopelvic mismatch lessen the potential for an increase in the postoperative SL and LL after a TLIF, which is likely due to a 'ceiling' effect of an otherwise optimized spinal alignment. A greater anterior disk height and the presence of an annular tear are associated with decreased ∆SL.

Nuchal thickness and increased risk of surgical site infection in posterior cervical operations.

OBJECTIVE: Surgical site infections (SSI) are a common post-operative complication, which increase cost, length of stay, and morbidity. Many risk factors have been, identified including body mass index (BMI). The purpose of this study was to evaluate, whether nuchal thickness rather than BMI increases risk for post-operative SSI in, posterior approach cervical spine operations. METHODS: A retrospective review of 180 patients who underwent posterior cervical spine, surgery at the University of Florida was performed. Nuchal thickness was measured, from the ventral most point of the spinous process of C5 to the skin on mid-sagittal preoperative, imaging. Diabetes status, BMI, smoking status, duration of anesthesia, prior, operations, and subcutaneous layer thickness was also collected. Infections were, identified according to the Centers for Disease Control (CDC) definitions for SSI. Univariate and multivariate analyses were performed by a biostatistician. RESULTS: Twenty patients (11%) had SSI. Smoking status, nuchal thickness of greater, than 55 mm or less than 29.8 mm, and subcutaneous fat thickness were all associated, with SSI. Age (OR 0.99, p = 0.45), diabetes (OR 0.50, p = 0.37), BMI (OR 1.03, p = 0.35), and use of intraoperative antibiotic powder (OR 0.62, p = 0.35) were not associated with, infection. On multivariate analysis (adjusted for smoking status), nuchal thickness, (p < 0.0001), subcutaneous fat thickness (p < 0.0001), and the ratio of subcutaneous fat to, nuchal thickness (p < 0.0001) all remained associated with SSI. CONCLUSIONS: Nuchal thickness and subcutaneous fat thickness are associated with SSI, in patients undergoing posterior cervical spine surgery. Risk of infection increases with very thin and very thick nuchal measurements.