Large vessel occlusions (LVOs), variably defined as blockages of the proximal intracranial anterior and posterior circulation, account for approximately 24% to 46% of acute ischemic strokes. Commonly refractory to intravenous tissue plasminogen activator (tPA), LVOs place large cerebral territories at ischemic risk and cause high rates of morbidity and mortality without further treatment. Over the past few years, an abundance of high-quality data has demonstrated the efficacy of endovascular thrombectomy for improving clinical outcomes in patients with LVOs, transforming the treatment algorithm for affected patients. In this review, we discuss the epidemiology, pathophysiology, natural history, and clinical presentation of LVOs as a framework for understanding the recent clinical strides of the endovascular era.

OBJECTIVE In vivo and in vitro studies have demonstrated histological evidence of iatrogenic endothelial injury after stent retriever thrombectomy. However, noncontrast vessel wall (VW)–MRI is insufficient to demonstrate vessel injury. Authors of this study prospectively evaluated iatrogenic endothelial damage after stent retriever thrombectomy in humans by utilizing high-resolution contrast-enhanced VW-MRI. Characterization of VW-MRI changes in vessels subject to mechanical injury from thrombectomy may allow better understanding of the biological effects of this intervention. METHODS The authors prospectively recruited 11 patients for this study. The treatment group included 6 postthrombectomy patients and the control group included 5 subjects undergoing MRI for nonvascular indications. All subjects were evaluated on a Signa HD× 3.0-T MRI scanner with an 8-channel head coil. Both pre- and postcontrast T1-weighted Cube VW images as well as MR angiograms were acquired. Sequences obtained for evaluation of the brain parenchyma included diffusion-weighted, gradient echo, and T2-FLAIR imaging. Two independent neuroradiologists, who were blinded to the treatment status of each patient, determined the presence of VW enhancement. Patient age, National Institutes of Health Stroke Scale score on presentation, location of occlusion, stroke etiology, type of device used, number of device deployments, Thrombolysis in Cerebral Infarction (TICI) reperfusion score, stroke volume, and 90-day modified Rankin Scale score were also noted. RESULTS Postcontrast T1-weighted VW enhancement was detected in the M2 segment in 100% of the thrombectomy patients, in the M1 segment in 83%, and in the internal carotid artery in 50%. One patient also demonstrated A1 segment enhancement, which was attributable to thrombectomy treatment of that vessel segment during the same procedure. None of the control patients demonstrated VW enhancement of their intracranial vasculature on T1-weighted images. CONCLUSIONS The study findings suggest that VW injury incurred during stent retriever thrombectomy can be reliably detected utilizing contrast-enhanced 3-T VW-MRI. The results further demonstrate that endothelial injury is associated with oversizing of stent retrievers relative to the treated vessel. Further studies are needed to evaluate the clinical significance of endothelial injury and to characterize the differential effects of various devices.

BACKGROUND Effective decompression, arthrodesis, and correction of spinal conditions frequently utilize operative approaches that expose both the anterior and posterior spinal column. Until now, circumferential spinal column access often requires the surgeon to reposition and drape the patient multiple times or utilize a posterior only approach that has limited anterior correction capability or to utilize a lateral-only approach that complicates otherwise traditional posterior surgical maneuvers. OBJECTIVE To describe a technique utilizing a single surgical position that enables minimally disruptive anterior column correction with simultaneous access to the posterior spinal column. METHODS The operative technique for accessing the lateral lumbar interbody space from a prone transpsoas (PTP) approach is described. The rationale for this approach and a representative case example are reviewed. RESULTS The PTP approach was used to perform an L3-4 and L4-5 interbody fusion in a 71-yr-old female with spondylolisthesis, severe stenosis, and locked facets. The PTP approach enabled efficient completion of an anterior column correction, direct posterior decompression, multi-segment pedicle fixation, and maintenance of alignment, all while in a single prone position. There were no intraoperative or postoperative complications. CONCLUSION The authors’ early experience with the described PTP technique suggests it is not only feasible but offers some advantages, as it allows for single-position surgery maximizing both anterior and posterior column access and corrective techniques. Further follow-up studies of this technique are ongoing.

ObjectiveTo evaluate the cost-effectiveness of neuromuscular ultrasound (NMUS) for the evaluation of focal neuropathies.MethodsA prior prospective, randomized, double-blind controlled trial demonstrated that NMUS, when added to electrodiagnostic testing, resulted in improved clinical outcomes after 6 months of follow-up. From this study, we abstracted quality-adjusted life-years (QALYs) from the 36-item Short Form Health Survey and entered this health-utility estimate into a mixed trial and model-based cost-effectiveness analysis from the societal perspective. Costs of intervention (NMUS) were estimated from Medicare payment rates for Current Procedural Terminology codes. Health care use was otherwise estimated to be equal, but sensitivity analyses further examined this and other key assumptions. Incremental cost-effectiveness ratio (ICER) was used as the primary outcome with a willingness-to-pay threshold of $50,000 per QALY.ResultsThe predicted mean health outcome associated with use of NMUS was 0.079 QALY, and the mean cost was $37, resulting in an ICER of $463 per QALY. Results and conclusions remained robust across all sensitivity analyses, including variations in time horizon, initial distribution of health states, costs, and effectiveness.ConclusionsFrom a societal perspective, the addition of NMUS to electrodiagnostic testing when evaluating a focal neuropathy is cost-effective. A study of longer follow-up incorporating total health care use would further quantify the value of NMUS.ClinicalTrials.gov identifier:NCT01394822.