Ghaith, Abdul Karim

Abstract Background Spinal cord injury (SCI) induces complex secondary pathophysiological cascades, including microvascular disruption, glial activation, and chronic neuroinflammation. These vascular changes are dynamic and spatially heterogeneous across acute, subacute, and chronic phases. However, limitations in in vivo imaging resolution have impeded precise, longitudinal evaluation of spinal microcirculation. Objective To quantify post-SCI alterations in spinal cord vessel density, flow speed, and morphology over time using ultrasound localization microscopy (ULM), and to correlate these changes with chronic astrocytic reactivity assessed by GFAP expression. Methods Eleven Sprague-Dawley rats underwent T9–T11 laminectomy; nine received a standardized 200 kdyn contusion using the Infinite Horizons Impactor and were assigned to acute (24h), subacute (7d), and chronic (21d) groups (n = 3/group), while two served as uninjured controls. ULM was performed using a Vevo 3100 high-frequency ultrasound system with a 40 MHz transducer following intravenous Definity® microbubble injection. Vessel density (VD) and flow speed (FS) were quantified at the lesion epicenter and adjacent rostral/caudal regions. Arterial and venous compartments were distinguished by flow direction. Histological sections were stained for glial fibrillary acidic protein (GFAP), and %Area was quantified across phases. One-way ANOVA and Tukey’s test evaluated between-group differences; Pearson correlation identified phase-specific relationships between vascular metrics and chronic GFAP expression. Results ULM provided super-resolved imaging of spinal microvasculature at 5–10 µm resolution. Venous VD significantly declined from 0.92 ± 0.18 (acute) to 0.42 ± 0.23 (subacute) and 0.11 ± 0.07 (chronic, p < 0.001), particularly in dorsal regions. Arterial VD remained stable across timepoints (p > 0.05), while FS demonstrated transient reductions in both arterial and venous systems during the subacute phase. Chronic venous FS partially recovered by Day 21. GFAP-positive area increased significantly in the chronic group (3.3 ± 0.87%) compared to acute (1.52 ± 0.42%) and subacute (1.40 ± 0.05%) (p < 0.05), indicating delayed astrocyte reactivity. Correlation analysis revealed significant inverse associations between chronic GFAP %Area and early ventral venous density (r = − 1.0, p < 0.05), as well as positive correlations with chronic ventral arterial FS (r = 1.0, p < 0.01), suggesting early microvascular deficits may predict long-term gliosis. Conclusion This study demonstrates the feasibility and power of ULM to quantify dynamic microvascular remodeling in SCI with unprecedented resolution. Venous rarefaction precedes chronic astrocytosis, while arterial flow speed partially recovers over time. These findings highlight key spatiotemporal biomarkers of injury progression and support the use of ULM as a noninvasive platform for monitoring SCI pathophysiology and guiding therapeutic timing.

Background/Objectives: Spinal astrocytomas (SA) represent 30–40% of all intramedullary spinal cord tumors (IMSCTs) and present significant clinical challenges due to their aggressive behavior and potential for recurrence. We aimed to pool the evidence on SA and investigate predictors of regrowth or recurrence after surgical resection. Methods: A systematic review and meta-analysis were conducted on peer-reviewed human studies from several databases covering the field of SA. Data were collected including sex, age, tumor location, extent of resection, histopathological diagnosis, and adjuvant therapy to identify predictors of SA recurrence. Recurrence was defined as failure of local tumor control or regrowth after treatment. Results: A total of 53 studies with 1365 patients were included in the meta-analysis. A postoperative deterioration in neurological outcomes, as assessed by the modified McCormick scale, was noted in most of the patients. The overall recurrence rate amounted to 41%. On meta-analysis, high-grade WHO tumors were associated with higher odds of recurrence (OR = 2.65; 95% CI: 1.87, 3.76; p = 0.001). Similarly, GTR was associated with lower odds of recurrence compared to STR (OR = 0.33; 95% CI: 0.18, 0.60; p = 0.0003). Sex (p = 0.5848) and tumor location (p = 0.3693) did not show any significant differences in the odds of recurrence. Intraoperative neurophysiological monitoring was described in 8 studies and adjuvant radiotherapy in 41 studies. Conclusions: The results highlight the significant importance of tumor grade and extent of resection in patient prognosis. The role of adjuvant radiotherapy remains unclear, with most studies suggesting no differences in outcomes, with limitations due to potential confounders.

BACKGROUND AND OBJECTIVES: Epilepsy is considered one of the most prevalent and severe chronic neurological disorders worldwide. Our study aims to analyze the national trends in different treatment modalities for individuals with drug-resistant epilepsy and investigate the outcomes associated with these procedural trends in the United States. METHODS: Using the National Inpatient Sample database from 2010 to 2020, patients with drug-resistant focal epilepsy who underwent laser interstitial thermal therapy (LITT), open surgical resection, vagus nerve stimulation (VNS), or responsive neurostimulation (RNS) were identified. Trend analysis was performed using piecewise joinpoint regression. Propensity score matching was used to compare outcomes between 10 years prepandemic before 2020 and the first peak of the COVID-19 pandemic. RESULTS: This study analyzed a total of 33 969 patients with a diagnosis of drug-resistant epilepsy, with 3343 patients receiving surgical resection (78%), VNS (8.21%), RNS (8%), and LITT (6%). Between 2010 and 2020, there was an increase in the use of invasive electroencephalography monitoring for seizure zone localization ( P = .003). There was an increase in the use of LITT and RNS ( P < .001), while the use of surgical resection and VNS decreased over time ( P < .001). Most of these patients (89%) were treated during the pre-COVID pandemic era (2010-2019), while a minority (11%) underwent treatment during the COVID pandemic (2020). After propensity score matching, the rate of pulmonary complications, postprocedural hematoma formation, and mortality were slightly higher during the pandemic compared with the prepandemic period ( P = .045, P = .033, and P = .026, respectively). CONCLUSION: This study indicates a relative decrease in the use of surgical resections, as a treatment for drug-resistant focal epilepsy. By contrast, newer, minimally invasive surgical approaches including LITT and RNS showed gradual increases in usage.

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.

BACKGROUND AND OBJECTIVES: Nongeneral anesthesia (non-GA) spine surgery is growing in popularity and has facilitated earlier postoperative recovery, reduced cost, and fewer complications compared with spine surgery under general anesthesia (GA). Changes in reimbursement policies have been demonstrated to correlate with clinical practice; however, they have yet to be studied for GA vs non-GA spine procedures. We aimed to investigate trends in physician reimbursement for GA vs non-GA spine surgery in the United States. METHODS: We queried the ACS-NSQIP for GA and non-GA (regional, epidural, spinal, and anesthesia care/intravenous sedation) spine surgeries during 2011–2020. Work relative value units per operative hour (wRVUs/h) were retrieved for decompression or stabilization of the cervical, thoracic, and lumbar spine. Propensity score matching (1:1) was performed using all baseline variables. RESULTS: We included 474 706 patients who underwent spine decompression or stabilization procedures. GA was used in 472 248 operations, whereas 2458 operations were non-GA. The proportion of non-GA spine operations significantly increased during the study period. Operative times ( P < .001) and length of stays ( P < .001) were shorter in non-GA when compared with GA procedures. Non-GA lumbar procedures had significantly higher wRVUs/h when compared with the same procedures performed under GA (decompression; P < .001 and stabilization; P = .039). However, the same could not be said about cervicothoracic procedures. Lumbar decompression surgeries using non-GA witnessed significant yearly increase in wRVUs/h ( P < .01) contrary to GA ( P = .72). Physician reimbursement remained stable for procedures of the cervical or thoracic spine regardless of the anesthesia. CONCLUSION: Non-GA lumbar decompressions and stabilizations are associated with higher and increasing reimbursement trends (wRVUs/h) compared with those under GA. Reimbursement for cervical and thoracic surgeries was equal regardless of the type of anesthesia and being relatively stable during the study period. The adoption of a non-GA technique relative to the GA increased significantly during the study period.

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 12–17 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.