Jesse J. Liu

Brainstem Opioidergic System Is Involved in Early Response to Experimental SAH

Subarachnoid hemorrhage (SAH) is a form of stroke with high rates of mortality and permanent disability for patients who survive the initial event. Previous research has focused on delayed cerebral vasospasm of large conduit arteries as the cause of poor long-term outcomes after SAH. New evidence suggests that acute failure to restore cerebral blood flow (CBF) after SAH may be setting the stage for delayed ischemic neurological deficits. Our lab previously demonstrated that the rostral ventromedial medulla (RVM), an autonomic and sensorimotor integration center, is important for maintaining CBF after experimental SAH. In this study, we have demonstrated that ablation of μ-opioid receptor containing cells with dermorphin conjugates in the RVM results in a high mortality rate after experimental SAH and, in survivors, causes a dramatic decrease in CBF. Further, locally blocking the μ-opioid receptor with the antagonist naltrexone attenuated the reduction in CBF secondary to experimental SAH. Saturating μ-opioid receptors with the agonist [d-Ala(2),NMe-Phe(4),Gly-ol(5)]-encephalin (DAMGO) had no effect. Taken together, these results suggest that SAH activates opioidergic signaling in the RVM with a resultant reduction in CBF. Further, cells in the RVM that contain μ-opioid receptors are important for survival after acute SAH. We propose that failure of the RVM μ-opioid receptor cells to initiate the compensatory CBF response sets the stage for acute and delayed ischemic injury following SAH.

Timing of deep vein thrombosis formation after aneurysmal subarachnoid hemorrhage

OBJECT Deep vein thrombosis (DVT) is a common complication of aneurysmal subarachnoid hemorrhage (aSAH). The time period of greatest risk for developing DVT after aSAH is not currently known. aSAH induces a prothrombotic state, which may contribute to DVT formation. Using repeated ultrasound screening, the hypothesis that patients would be at greatest risk for developing DVT in the subacute post-rupture period was tested. METHODS One hundred ninety-eight patients with aSAH admitted to the Oregon Health & Science University Neurosciences Intensive Care Unit between April 2008 and March 2012 were included in a retrospective analysis. Ultrasound screening was performed every 5.2 ± 3.3 days between admission and discharge. The chi-square test was used to compare DVT incidence during different time periods of interest. Patient baseline characteristics as well as stroke severity and hospital complications were evaluated in univariate and multivariate analyses. RESULTS Forty-two (21%) of 198 patients were diagnosed with DVT, and 3 (2%) of 198 patients were symptomatic. Twenty-nine (69%) of the 42 cases of DVT were first detected between Days 3 and 14, compared with 3 cases (7%) detected between Days 0 and 3 and 10 cases (24%) detected after Day 14 (p < 0.05). The postrupture 5-day window of highest risk for DVT development was between Days 5 and 9 (40%, p < 0.05). In the multivariate analysis, length of hospital stay and use of mechanical prophylaxis alone were significantly associated with DVT formation. CONCLUSIONS DVT formation most commonly occurs in the first 2 weeks following aSAH, with detection in this cohort peaking between Days 5 and 9. Chemoprophylaxis is associated with a significantly lower incidence of DVT.

The Effect and Use of Milestones in the Assessment of Neurological Surgery Residents and Residency Programs.

OBJECTIVES The purpose of this study was to determine the effect of the Accreditation Council for Graduate Medical Education Milestones on the assessment of neurological surgery residents. The authors sought to determine the feasibility, acceptability, and utility of this new framework in making judgments of progressive competence, its implementation within programs, and the influence on curricula. Residents were also surveyed to elicit the effect of Milestones on their educational experience and professional development. DESIGN, SETTING, AND PARTICIPANTS In 2015, program leadership and residents from 21 neurological surgery residency programs participated in an online survey and telephone interview in which they reflected on their experiences with the Milestones. Survey data were analyzed using descriptive statistics. Interview transcripts were analyzed using grounded theory. RESULTS Response themes were categorized into 2 groups: outcomes of the Milestones implementation process, and facilitators and barriers. Because of Milestones implementation, participants reported changes to the quality of the assessment process, including the ability to identify struggling residents earlier and design individualized improvement plans. Some programs revised their curricula based on training gaps identified using the Milestones. Barriers to implementation included limitations to the adoption of a developmental progression model in the context of rotation block schedules and misalignment between progression targets and clinical experience. The shift from time-based to competency-based evaluation presented an ongoing adjustment for many programs. Organized preparation before clinical competency committee meetings and diverse clinical competency committee composition led to more productive meetings and perceived improvement in promotion decisions. CONCLUSIONS The results of this study can be used by program leadership to help guide further implementation of the Milestones and program improvement. These results also help to guide the evolution of Milestones language and their implementation across specialties.

Minimal Access Posterior Approach for Extrapleural Thoracic Sympathectomy: A Cadaveric Study and Cases.

OBJECTIVE Operatively, video-assisted thoracoscopic sympathectomy (VATS) involves pleural entry and poses risk in small children and patients with pulmonary disease. A conventional posterior sympathectomy is more invasive than VATS. We investigated a cadaveric feasibility study of a minimal access posterior approach for endoscopic extrapleural sympathectomy and discuss this minimal approach in children with cardiac sympathectomy. METHODS A posterior endoscopic extrapleural approach for thoracic sympathectomy was performed using lightly embalmed cadavers; surgical corridor depth, width, and associated pleural violation were recorded. Two pediatric cases undergoing secondary prevention for breakthrough cardiac dysrhythmias using this approach are discussed: case 1, a 9-year-old girl with refractory long QT syndrome; and case 2, a 13-year-old boy with hypertrophic cardiomyopathy. RESULTS The cadaveric study supported 100% identification of a craniocaudal-oriented sympathetic chain using an 18-mm tubular retractor, and a 10% pleural violation rate. There were no clinically significant pneumothoracies in either proof of concept cases. CONCLUSIONS Minimal access posterior extrapleural sympathectomy is feasible to expose the sympathetic chain in the thoracic region with good visualization using either endoscopic or microscopic magnification. Single-position bilateral thoracic sympathectomy can be performed in pediatric patients with life-threatening ventricular arrhythmias. Based on the cadaveric study and the 2 preliminary cases, we believe that a posterior minimal access approach allows safe and effective access to the thoracic sympathetic chain for causes requiring sympathectomy using single positioning, with minimal risk of pneumothorax or Horner syndrome.

Anterior Spinal Reconstruction to the Clivus Using an Expandable Cage After C2 Chordoma Resection Via a Labiomandibular Glossotomy Approach: A Technical Report

INTRODUCTION En bloc resection of high-cervical chordomas is a technically challenging procedure associated with significant morbidity. Two key components of this procedure include the approach and the method of spinal reconstruction. A limited number of reported cases of en bloc resection of high-cervical chordomas have been reported in the literature. CASE PRESENTATION We report a novel case using an expandable cage to reconstruct the anterior spinal column above C2 with fixation to the clivus. We also report a novel anterior approach to the high-cervical spine via a midline labiomandibular glossotomy. We detail the management of complications related to 2 instances of wound dehiscence and hardware exposure requiring two additional operations. The final surgical procedure involved explantation of the anterior cervical plate and use of a vascularized radial graft to close the posterior pharyngeal defect and protect the hardware. At 26-month follow-up, the patient remained disease free without any neurologic deficit. DISCUSSION We report the novel use of the midline labiomandibular glossotomy for surgical approach and reconstruction of the anterior column to the clivus with an expandable cage. The unique features of this operative strategy allowed the surgical team to tailor the construct intraoperatively, resulting in solid arthrodesis without significant neurologic sequelae. CONCLUSIONS Labiomandibular glossotomy for approach to high anterior cervical chordomas followed by craniospinal reconstruction to the clivus with an expandable cage represents a novel technique for managing high cervical chordomas.

Improving Efficiency and Mapping Surgical Procedures Using Lean Methods

Abstract The delivery of high-value and low-cost health care is an increasingly urgent directive of public health institutions. As national health expenditure becomes an increasingly higher proportion of the gross domestic product, governments and health care systems are trying to find ways to reduce the cost of health care without reducing the overall health of the population. Recently, Lean methodologies have been borrowed and adapted from automobile assembly lines to health care delivery. These methods have been used in places ranging from the clinic, to ambulatory surgery centers, to high-volume hospital operating rooms to improve the quality and efficiency of health care delivery while reducing costs.

Eliminating Unnecessary Diagnostic Imaging and Labs

Abstract In the era of value-based health care, reducing waste and decreasing cost is a priority for health care systems. A primary challenge in improving health care value is to maintain or improve outcomes while reducing the cost of care. Lean Production, widely used in manufacturing industries, aims to reduce cost and eliminate waste and can be used to achieve similar ends in medicine. By assimilating these principles, health care systems can identify wasteful processes to further the Triple Aim (improve outcomes, reduce costs, and improve patient experience). At Oregon Health & Science University, an initiative was created to evaluate the efficacy of imaging obtained by the neuroscience service line and limit nonessential images. A single standardized procedure, retrosigmoid craniectomy for microvascular decompression, was analyzed. Retrospective analyses of institutional data were performed prior to prospective changes in clinical practice. Data collected after implementation of the clinical changes demonstrated similar outcomes and reduced cost, thereby increasing value.