The Role of Alginate Hydrogels as a Potential Treatment Modality for Spinal Cord Injury: A Comprehensive Review of the Literature

Objective To comprehensively characterize the utilization of alginate hydrogels as an alternative treatment modality for spinal cord injury (SCI). Methods An extensive review of the published literature on studies using alginate hydrogels to treat SCI was performed. The review of the literature was performed using electronic databases such as PubMed, EMBASE, and OVID MEDLINE electronic databases. The keywords used were “alginate,” “spinal cord injury,” “biomaterial,” and “hydrogel.” Results In the literature, we identified a total of 555 rat models that were treated with alginate scaffolds for regenerative biomarkers. Alginate hydrogels were found to be efficient and promising substrates for tissue engineering, drug delivery, neural regeneration, and cellbased therapies for SCI repair. With its ability to act as a pro-regenerative and antidegenerative agent, the alginate hydrogel has the potential to improve clinical outcomes. Conclusion The emerging developments of alginate hydrogels as treatment modalities may support current and future tissue regenerative strategies for SCI

Abstract 175: Impact of COVID‐19 on Intracranial Aneurysm Treatment and Outcomes: A Nationwide Propensity Score Matched Study.

Introduction The coronavirus disease 2019 (COVID‐19) pandemic has had a global impact on healthcare systems. There is limited data on the influence of COVID‐19 on treatment and outcomes in patients with intracranial aneurysms. We aimed to investigate the impact of COVID‐19 on the overall complications, including ischemic stroke and subarachnoid hemorrhage (SAH) rates in patients treated for intracranial aneurysms (IAs). Methods This national, multicenter, retrospective cohort study included patients diagnosed and treated for IAs from January 2016 to December 2020 in the National Inpatient Sample (NIS). A total of 57,715 admissions were identified. Of these, 45,979 occurred pre‐COVID and 11,736 during the COVID pandemic period. The outcome data points included the occurrence of postprocedural ischemic strokes or SAHs, death, non‐routine discharge, total charges (US dollars), and length of stay (days). A 1:1 propensity score matching protocol was applied using a K‐nearest neighbor approach to evaluate differences in the outcome data points between the pre‐COVID and during COVID periods. The trends during the study period were assessed using piecewise joinpoint regression with the Mann‐Kendall test. Results Overall, the mean age was 65 years, with most of the patients (69.9%) being females. Endovascular interventions were performed in 82.9% of pre‐COVID IAs admissions compared to 82.4% during the COVID period, while open surgical treatment was performed in 17.1% of pre‐COVID and 17.6% of the patients during COVID (p=0.625). After matching, there were no differences in length of stay (p=0.266), non‐home discharge (p=0.475), and in‐hospital mortality rates (p=0.305) between the two periods; however, the overall complication rate was significantly higher during the pandemic (31.1% vs. 28.3%; p<0.001). From 2016 to 2020, an upward trend in hospitalizations for ischemic stroke was seen among patients treated for IAs (6.1% to 7.9%; p=0.04). No trends were observed with respect to the occurrence of SAH or death (p=0.31). Patients hospitalized after treatment of IAs during the COVID pandemic had significantly higher odds of ischemic strokes (OR 1.13; 95% CI 1.05 to 1.22; p=0.03) but not SAH (OR 0.97; 95% CI 0.88 to 1.06; p=0.89). Conclusion The COVID‐19 pandemic has significantly impacted the healthcare system. In patients receiving treatment for IAs, this analysis noted a correlation between the COVID‐19 pandemic and postoperative complications, notably ischemic strokes. Unraveling the pandemic’s “black box” leads to awareness of plausible breaches within the system, which acts as a crucial component in improving situational readiness and preparedness in the event of similar large‐scale crises

Limitations in Evaluating Machine Learning Models for Imbalanced Binary Outcome Classification in Spine Surgery : A Systematic Review

Clinical prediction models for spine surgery applications are on the rise, with an increasing reliance on machine learning (ML) and deep learning (DL). Many of the predicted outcomes are uncommon; therefore, to ensure the models' effectiveness in clinical practice it is crucial to properly evaluate them. This systematic review aims to identify and evaluate current research-based ML and DL models applied for spine surgery, specifically those predicting binary outcomes with a focus on their evaluation metrics. Overall, 60 papers were included, and the findings were reported according to the PRISMA guidelines. A total of 13 papers focused on lengths of stay (LOS), 12 on readmissions, 12 on non-home discharge, 6 on mortality, and 5 on reoperations. The target outcomes exhibited data imbalances ranging from 0.44% to 42.4%. A total of 59 papers reported the model's area under the receiver operating characteristic (AUROC), 28 mentioned accuracies, 33 provided sensitivity, 29 discussed specificity, 28 addressed positive predictive value (PPV), 24 included the negative predictive value (NPV), 25 indicated the Brier score with 10 providing a null model Brier, and 8 detailed the F1 score. Additionally, data visualization varied among the included papers. This review discusses the use of appropriate evaluation schemes in ML and identifies several common errors and potential bias sources in the literature. Embracing these recommendations as the field advances may facilitate the integration of reliable and effective ML models in clinical settings

The Virtual Vision of Neurosurgery: How Augmented Reality and Virtual Reality are Transforming the Neurosurgical Operating Room.

BACKGROUND: In this era of imagination and technological innovation, mixed reality systems such as virtual reality (VR) and augmented reality (AR) are contributing to a wide array of neurosurgical care, from the betterment of surgical planning and surgical comfort to even novel treatments and improved resident education. These systems can augment procedures that require high-level dexterity such as minimally invasive surgery, tumor excisions, as well as peripheral and neurovascular surgery. Herein, the authors will define and compare the technological features, indications, and characterized outcomes of VR and AR systems in the context of neurosurgery through a review of the literature to date. Moreover, this review will discuss the limitations of VR and AR while including an overview of the cost effectiveness of each of these systems. METHODS: An extensive review of published literature on augmented reality and virtual reality was performed utilizing PubMed, OVID Medline, and EMBASE journals from January 1, 2006 to April 2, 2022. Terms used for the search included augmented reality, spinal surgery, virtual reality, and neurosurgery. RESULTS: The search yielded full text English language-related articles regarding virtual and augmented reality application, limitations, and functional outcomes in neurosurgery. An initial set of 121 studies were screened and reviewed for content. There were 13 studies included that involved 162 patients, 550 screw placements, 58 phantom spines, and learning points from simulation training of 276 involved residents. CONCLUSION: This literature review examines recent research into virtual and augmented reality applications in neurosurgical care. The literature establishes there are technological features, indications, outcomes, limitations, and cost effectiveness differences between these systems. Based on ongoing and evolving applications of the VR and AR systems, their innovative potential they make available to the future of neurosurgical patient care makes clear the need for further studies to understand the nuances between their differing technological advances

Percutaneous Closure Device for the Carotid artery: An integrated review and design analysis

Endovascular thrombectomies (EVTs) are the current standard of care therapy for treating acute ischemic strokes. While access through the femoral or radial arteries is routine, up to 20% of EVTs through these sites are unable to access the cerebral vasculature on the first pass. These shortcomings are commonly due to tortuous vasculature, atherosclerotic arteries, and type III aortic arch, seen especially in the elderly population. Recent studies have shown the benefits of accessing the cerebral vasculature through a percutaneous direct carotid puncture (DCP), which can reduce the time of the procedure by half. However, current vascular closure devices (VCDs) designed for the femoral artery are not suited to close the carotid artery due to the anatomical differences. This unmet clinical need further limits a DCP approach. Thus, to foster safe adoption of this potential approach, a VCD designed specifically for the carotid artery is needed. In this review, we outline the major biomechanical properties and shortcomings of current VCDs and propose the requirements necessary to effectively design and develop a carotid closure device

The Use of Ultrasonic Bone Scalpel (UBS) in Unilateral Biportal Endoscopic Spine Surgery (UBESS): Technical Notes and Outcomes

Study Design: Case Series and Technical Note, Objective: UBS has been extensively used in open surgery. However, the use of UBS during UBESS has not been reported in the literature. The aim of this study was to describe a new spinal surgical technique using an ultrasonic bone scalpel (UBS) during unilateral biportal endoscopic spine surgery (UBESS) and to report the preliminary results of this technique. Methods: We enrolled patients diagnosed with lumbar spinal stenosis who underwent single-level UBESS. All patients were followed up for more than 12 months. A unilateral laminotomy was performed after bilateral decompression under endoscopy. We used the UBS system after direct visualization of the target for a bone cut. We evaluated the demographic characteristics, diagnosis, operative time, and estimated blood loss of the patients. Clinical outcomes included the visual analog scale (VAS), the Oswestry Disability Index (ODI), the modified MacNab criteria, and postoperative complications. Results: A total of twenty patients (five males and fifteen females) were enrolled in this study. The mean follow-up period was 13.2 months (range 12&ndash;17 months). The VAS score, ODI, and modified MacNab criteria classification improved after the surgery. A minimal mean blood loss of 22.1 mL was noted during the operation. Only one patient experienced neuropraxia, which resolved within 2 weeks. There was no durotomy, iatrogenic pars fracture, or infection. Conclusions: In conclusion, our study represents the first report of the use of UBS during UBESS. Our findings demonstrate that this technique is safe and efficient, with improved clinical outcomes and minimal complications. These preliminary results warrant further investigation through larger clinical studies with longer follow-up periods to confirm the effectiveness of this technique in the treatment of lumbar spinal stenosis

Impact of the COVID-19 pandemic on intracranial aneurysm treatment and associated Outcomes: A nationwide US-based study

Objective: Limited data on the treatment and outcomes of patients with intracranial aneurysms (ICAs) in the (coronavirus disease 2019) COVID-19 era is available. Our objective was hence to investigate the impact of the pandemic on the overall complication rate and postprocedural ischemic strokes specifically, in patients treated for ICAs. Methods: The National Inpatient sample database was used. The main outcomes were the occurrence of postprocedural ischemic strokes, as well as death, non-routine discharge, total charges (US dollars), and length of stay (days). Propensity score matching was applied to compare the pre- and COVID-19 periods. Trends were assessed using piecewise joinpoint regression with the Mann-Kendall test. Results: A total of 57,715 patients were included in the study. The mean age was 65 years, with most of the patients (69.9 %) being females. After matching, no differences in length of stay (p = 0.266), non-home discharge (p = 0.475), and in-hospital mortality rates (p = 0.305) between the two periods were found. However, the overall complication rate was significantly higher during the pandemic (31.1 % vs. 28.3 %; p < 0.001). Patients hospitalized after treatment of ICAs during the COVID-19 pandemic had significantly higher odds of ischemic strokes (OR 1.13; 95 % CI 1.05 to 1.22; p = 0.03), even when adjusting for other factors. Conclusions: There is no denying that the COVID-19 pandemic has significantly impacted the healthcare system in several aspects. One aspect highlighted in this study, patient outcomes, was especially notable among patients’ receiving treatment for ICAs. Our results suggest a correlation between the COVID-19 pandemic and postprocedural complications, of which ischemic strokes were the most notable

Rathke cleft cyst with size fluctuation: A systematic literature review and case illustration

Background: Rathke cleft cysts (RCCs) are known sellar/suprasellar lesions that can grow and become symptomatic. For most asymptomatic lesions, stability is a typical outcome of surveillance; however, random relapse or cyst size fluctuation may also be observed. The conventional treatment for growing cysts is transsphenoidal removal. Methods: A literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. For significance, all journals were screened. Only records of tissue diagnosed RCCs with changes in size were included. Age and sex at diagnosis, size of the lesion, symptoms (if any), pituitary dysfunction, follow-up period, and size reduction were included in the data items. Results: A total of 4 articles where selected after the second exclusion method. Three articles where case series and one was a case report. Eight total patients where histologically proven to have Rathke cleft cysts which fluctuated in size without intervention. Conclusion: This review shows that RCCs can decrease or fluctuate in size following a dynamic process that is not fully understood. In the absence of symptoms, a larger cyst or an absolute increase in a cyst size, which may traditionally provoke an early surgical intervention, should be assessed and managed carefully to avoid potentially unneeded surgical morbidity

Global Incidence and Risk Factors Associated With Postoperative Urinary Retention Following Elective Inguinal Hernia Repair

Importance Postoperative urinary retention (POUR) is a well-recognized complication of inguinal hernia repair (IHR). A variable incidence of POUR has previously been reported in this context, and contradictory evidence surrounds potential risk factors.Objective To ascertain the incidence of, explore risk factors for, and determine the health service outcomes of POUR following elective IHR.Design, Setting, and Participants The Retention of Urine After Inguinal Hernia Elective Repair (RETAINER I) study, an international, prospective cohort study, recruited participants between March 1 and October 31, 2021. This study was conducted across 209 centers in 32 countries in a consecutive sample of adult patients undergoing elective IHR.Exposure Open or minimally invasive IHR by any surgical technique, under local, neuraxial regional, or general anesthesia.Main Outcomes and Measures The primary outcome was the incidence of POUR following elective IHR. Secondary outcomes were perioperative risk factors, management, clinical consequences, and health service outcomes of POUR. A preoperative International Prostate Symptom Score was measured in male patients.Results In total, 4151 patients (3882 male and 269 female; median [IQR] age, 56 [43-68] years) were studied. Inguinal hernia repair was commenced via an open surgical approach in 82.2% of patients (n = 3414) and minimally invasive surgery in 17.8% (n = 737). The primary form of anesthesia was general in 40.9% of patients (n = 1696), neuraxial regional in 45.8% (n = 1902), and local in 10.7% (n = 446). Postoperative urinary retention occurred in 5.8% of male patients (n = 224), 2.97% of female patients (n = 8), and 9.5% (119 of 1252) of male patients aged 65 years or older. Risk factors for POUR after adjusted analyses included increasing age, anticholinergic medication, history of urinary retention, constipation, out-of-hours surgery, involvement of urinary bladder within the hernia, temporary intraoperative urethral catheterization, and increasing operative duration. Postoperative urinary retention was the primary reason for 27.8% of unplanned day-case surgery admissions (n = 74) and 51.8% of 30-day readmissions (n = 72).Conclusions The findings of this cohort study suggest that 1 in 17 male patients, 1 in 11 male patients aged 65 years or older, and 1 in 34 female patients may develop POUR following IHR. These findings could inform preoperative patient counseling. In addition, awareness of modifiable risk factors may help to identify patients at increased risk of POUR who may benefit from perioperative risk mitigation strategies