Tecle, Najib E. El

Abstract BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm. OBJECTIVE To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT). METHODS HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during follow-up, aneurysm occlusion stability, and clinical outcome at final follow-up. RESULTS A total of 600 patients were randomized (HES, n = 297 and BPC, n = 303), including 28% with ruptured aneurysms. Recurrence occurred in 11 (4.4%) subjects in the HES arm and 44 (15.4%) subjects in the BPC arm ( P = .002). While the initial occlusion rate was higher with BPC, the packing density and both major and minor recurrence rates were in favor of HES. Secondary endpoints including adverse events, retreatment, hemorrhage, mortality, and clinical outcome did not differ between arms. CONCLUSION Coiling of small-to-medium aneurysms with second-generation HES resulted in less recurrence when compared to BPC, without increased harm. These data further support the use of the second-generation HES for the embolization of intracranial aneurysms. Video Abstract

Abstract BACKGROUND For optimizing high-grade glioma resection, 5-aminolevulinic acid is a reliable tool. However, its efficacy in low-grade glioma resection remains unclear. OBJECTIVE To study the role of 5-aminolevulinic acid in low-grade glioma resection and assess positive fluorescence rates and the effect on the extent of resection. METHODS A systematic review of PubMed, Google Scholar, and Cochrane was performed from the date of inception to February 1, 2019. Studies that correlated 5-aminolevulinic acid fluorescence with low-grade glioma in the setting of operative resection were selected. Studies with biopsy only were excluded. Positive fluorescence rates were calculated. The quality index of the selected papers was provided. No patient information was used, so Institutional Review Board approval and patient consent were not required. RESULTS A total of 12 articles met the selection criteria with 244 histologically confirmed low-grade glioma patients who underwent microsurgical resection. All patients received 20 mg/kg body weight of 5-aminolevulinic acid. Only 60 patients (n = 60/244; 24.5%) demonstrated visual intraoperative 5-aminolevulinic acid fluorescence. The extent of resection was reported in 4 studies; however, the data combined low- and high-grade tumors. Only 2 studies reported on tumor location. Only 3 studies reported on clinical outcomes. The Zeiss OPMI Pentero microscope was most commonly used across all studies. The average quality index was 14.58 (range: 10-17), which correlated with an overall good quality. CONCLUSION There is an overall low correlation between 5-aminolevulinic acid fluorescence and low-grade glioma. Advances in visualization technology and using standardized fluorescence quantification methods may further improve the visualization and reliability of 5-aminolevulinic acid fluorescence in low-grade glioma resection.

Abstract BACKGROUND 5-aminolevulinic acid is a reliable tool for optimizing high-grade glioma resection. However, its efficacy in low-grade glioma resection remains unclear. OBJECTIVE To study the role of 5-aminolevulinic acid in low-grade glioma resection and assess positive fluorescence rates and effect on the extent of resection. METHODS A systematic review of PubMed, Google Scholar, and Cochrane was performed from the date of inception to February 1, 2019. Studies that correlated 5-aminolevulinic acid fluorescence with low-grade glioma in the setting of operative resection were selected. Studies with biopsy only were excluded. Positive fluorescence rates were calculated. Quality index of the selected papers using the Downs and Black criteria checklist was provided. RESULTS Twelve articles met the selection criteria with 244 histologically-confirmed low-grade glioma patients who underwent microsurgical resection. All patients received 20 mg/kg body weight of 5-aminolevulinic acid. Only 60 patients (n=60/244; 24.5%) demonstrated visual intra-operative 5-aminolevulinic acid fluorescence. The extent of resection was reported in 4 studies, however, the data combined low- and high-grade tumors. Only 2 studies reported on tumor location. Only 3 studies reported on clinical outcomes. The Zeiss OPMI Pentero microscope was most commonly used across all studies. The average quality index was 14.58 (range: 10–17) which correlated with an overall good quality. CONCLUSION There is an overall low correlation between 5-aminolevulinic acid fluorescence and low-grade glioma. Advances in visualization technology and using standardized fluorescence quantification methods may further improve the visualization and reliability of 5-aminolevulinic acid fluorescence in low-grade glioma resection.

OBJECTIVEThe natural history of complete spinal cord injury (SCI) is poorly studied. The classically quoted rate of improvement or conversion for patients with American Spinal Injury Association (ASIA) grade A (ASIA A) injuries is 15%–20%; however, data supporting this rate are very limited. In this paper, the authors conducted a meta-analysis of modern data reporting on ASIA A patients and evaluated factors affecting the natural history of the disease.METHODSThe authors conducted a systematic literature review of all randomized clinical trials (RCTs) and observational studies of patients with traumatic SCI. The Embase, MEDLINE, PubMed, Scopus, CINAHL, and Cochrane databases were reviewed for all studies reporting on SCI and published after 1992. A meta-analysis was conducted using the DerSimonian and Laird (random-effects) model with a summary odds ratio analysis.RESULTSEleven RCTs and 9 observational studies were included in the final analysis. Overall, the 20 included studies reported on 1162 patients with ASIA A injuries. The overall conversion rate was 28.1%, with 327 of 1162 patients improving to at least ASIA B. The overall rate of conversion noted in cervical spine injuries was 33.3%, whereas that in thoracic injuries was 30.6%. Patients undergoing early surgery had a higher rate of conversion (46.1%) than patients undergoing late surgery (25%) (OR 2.31, 95% CI 1.08–4.96, p = 0.03).CONCLUSIONSThe overall rate of conversion of ASIA A SCIs from pooled data of prospective trials and observational series is 28.1%. This rate of conversion is higher than what is reported in the literature. Early surgery is predictive of a higher conversion rate. However, there are not enough data to provide conclusions pertaining to the efficacy of biological and medical therapies.

Abstract BACKGROUND: The potential for simulation-based learning in neurosurgical training has led the Congress of Neurosurgical Surgeons to develop a series of simulation modules. The Northwestern Objective Microanastomosis Assessment Tool (NOMAT) was created as the corresponding assessment tool for the Congress of Neurosurgical Surgeons Microanastomosis Module. The face and construct validity of the NOMAT have been previously established. OBJECTIVE: To further validate the NOMAT by determining its interrater reliability (IRR) between raters of varying levels of microsurgical expertise. METHODS: The NOMAT was used to assess residents’ performance in a microanastomosis simulation module in 2 settings: Northwestern University and the Society of Neurological Surgeons 2014 Boot Camp at the University of Indiana. At Northwestern University, participants were scored by 2 experienced microsurgeons. At the University of Indiana, participants were scored by 2 postdoctoral fellows and an experienced microsurgeon. The IRR of NOMAT was estimated by computing the intraclass correlation coefficient using SPSS v22.0 (IBM, Armonk, New York). RESULTS: A total of 75 residents were assessed. At Northwestern University, 21 residents each performed microanastomosis on 2 model vessels of different sizes, one 3 mm and one 1 mm. At the University of Indiana, 54 residents performed a single microanastomosis procedure on 3-mm vessels. The intraclass correlation coefficient of the total NOMAT scores was 0.88 at Northwestern University and 0.78 at the University of Indiana. CONCLUSION: This study indicates high IRR for the NOMAT. These results suggest that the use of raters with varying levels of expertise does not compromise the precision or validity of the scale. This allows for a wider adoption of the scale and, hence, a greater potential educational impact.