Background and Purpose: The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level. Methods: All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded. Results: We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0–2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3–5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year. Conclusions: The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT03245866.

Radicular pain is characterized by radiating buttock and leg pain in a lumbar nerve root distribution, which may be accompanied by neurosensory and motor deficits. Radicular pain caused by lumbar disc herniation improves in most patients with conservative treatment only. Yet, 1 in 5 individuals will experience persistent symptoms and/or neurological deficit^1,2 such that lumbar discectomy may be indicated to surgically remove the herniated disc material. Recurrent herniation occurs in 7% to 18% of patients following discectomy^3-5 and a large defect in the annulus fibrosus after surgery is a major risk factor for reherniation.⁶ In a meta-analysis involving more than 1600 patients undergoing lumbar discectomy, the risk of symptom recurrence (odds ratio, 2.5; P = .004) and reoperation (odds ratio, 2.3; P < .001) was higher in patients with large vs small annular defects.⁶ Reoperations for lumbar disc herniation are more costly,⁴ less effective,^7,8 and are associated with higher risk of disability⁹ than primary procedures. Therefore, intraoperative strategies intended to close or occlude large annular defects may lower the clinical and economic burden related to surgery for recurrent herniation. This randomized clinical trial evaluated the 5-year clinical and radiographic outcomes of patients with large annular defects after lumbar microdiscectomy treated with or without a bone-anchored annular closure device.

Background and Purpose: Endovascular aneurysm treatment relies on a biological process, including cell migration for thrombus organization and growth of a neointima. To better understand aneurysm healing, our study explores the origin of neointima-forming and thrombus-organizing cells in a rat saccular sidewall aneurysm model. Methods: Saccular aneurysms were transplanted onto the abdominal aorta of male Lewis rats and endovascularly treated with coils (n=28) or stents (n=26). In 34 cases, GFP+ (green fluorescent protein)-expressing vital aneurysms were sutured on wild-type rats, and in 23 cases, decellularized wild-type aneurysms were sutured on GFP+ rats. Follow-up at 3, 7, 14, 21, and 28 days evaluated aneurysms by fluorescence angiography, macroscopic inspection, and microscopy for healing and inflammation status. Furthermore, the origin of cells was tracked with fluorescence histology. Results: In animals with successful functional healing, histological studies showed a gradually advancing thrombus organization over time characterized by progressively growing neointima from the periphery of the aneurysm toward the center. Cell counts revealed similar distributions of GFP+ cells for coil or stent treatment in the aneurysm wall (54.4% versus 48.7%) and inside the thrombus (20.5% versus 20.2%) but significantly more GFP+ cells in the neointima of coiled (27.2 %) than stented aneurysms (10.4%; P =0.008). Conclusions: Neointima formation and thrombus organization are concurrent processes during aneurysm healing. Thrombus-organizing cells originate predominantly in the parent artery. Neointima formation relies more on cell migration from the aneurysm wall in coiled aneurysms but receives greater contributions from cells originating in the parent artery in stent-treated aneurysms. Cell migration, which allows for a continuous endothelial lining along the parent artery’s lumen, may be a prerequisite for complete aneurysm healing after endovascular therapy. In terms of translation into clinical practice, these findings may explain the variability in achieving complete aneurysm healing after coil treatment and the improved healing rate in stent-assisted coiling.

Animal models make an important contribution to our basic understanding of the pathobiology of human brain aneurysms, are indispensable in testing novel treatment approaches, and are essential for training interventional neuroradiologists and neurosurgeons. Researchers are confronted with a broad diversity of models and techniques in various species. This systematic review aims to summarize and categorize extracranial aneurysm models and their characteristics, discuss advantages and disadvantages, and suggest the best use of each model. We searched the electronical Medline/PubMed database between 1950 and 2020 to identify main models and their refinements and technical modifications for creation of extracranial aneurysms. Each study included was assessed for aneurysm-specific characteristics, technical details of aneurysm creation, and histological findings. Among more than 4000 titles and abstracts screened, 473 studies underwent full-text analysis. From those, 68 different techniques/models in five different species were identified, analyzed in detail, and then grouped into one of the five main groups of experimental models as sidewall, terminal, stump, bifurcation, or complex aneurysm models. This systematic review provides a compact guide for investigators in selecting the most appropriate model from a range of techniques to best suit their experimental goals, practical considerations, and laboratory environment.

Background: Favorable outcomes are seen in up to 50% of patients with World Federation of Neurosurgical Societies (WFNS) grade V aneurysmal subarachnoid hemorrhage. Therefore, the usefulness of the current WFNS grading system for identifying the worst scenarios for clinical studies and for making treatment decisions is limited. We previously modified the WFNS scale by requiring positive signs of brain stem dysfunction to assign grade V. This study aimed to validate the new herniation WFNS grading system in an independent prospective cohort. Methods: We conducted an international prospective multicentre study in poor-grade aneurysmal subarachnoid hemorrhage patients comparing the WFNS classification with a modified version—the herniation WFNS scale (hWFNS). Here, only patients who showed positive signs of brain stem dysfunction (posturing, anisocoric, or bilateral dilated pupils) were assigned hWFNS grade V. Outcome was assessed by modified Rankin Scale score 6 months after hemorrhage. The primary end point was the difference in specificity of the WFNS and hWFNS grading with respect to poor outcomes (modified Rankin Scale score 4–6). Results: Of the 250 patients included, 237 reached the primary end point. Comparing the WFNS and hWFNS scale after neurological resuscitation, the specificity to predict poor outcome increased from 0.19 (WFNS) to 0.93 (hWFNS) (McNemar, P <0.001) whereas the sensitivity decreased from 0.88 to 0.37 ( P <0.001), and the positive predictive value from 61.9 to 88.3 (weighted generalized score statistic, P <0.001). For mortality, the specificity increased from 0.19 to 0.93 (McNemar, P <0.001), and the positive predictive value from 52.5 to 86.7 (weighted generalized score statistic, P <0.001). Conclusions: The identification of objective positive signs of brain stem dysfunction significantly improves the specificity and positive predictive value with respect to poor outcome in grade V patients. Therefore, a simple modification—presence of brain stem signs is required for grade V—should be added to the WFNS classification. Registration: URL: https://clinicaltrials.gov ; Unique identifier: NCT02304328.