Clinical Practice Variation and Outcomes for Stanford Type A Aortic Dissection Repair Surgery in Maryland: Report from a Statewide Quality Initiative

Abstract

Background Stanford Type A aortic dissection repair surgery is associated with high mortality and clinical practice remains variable among hospitals. Few studies have examined statewide practice variation. Methods Patients who had Stanford Type A aortic dissection repair surgery in Maryland between July 1, 2014 and June 30, 2018 were identified using the Maryland Cardiac Surgery Quality Initiative (MCSQI) database. Patient demographics, comorbidities, surgery details, and outcomes were compared between hospitals. We also explored the impact of arterial cannulation site and brain protection technique on outcome. Results A total of 233 patients were included from eight hospitals during the study period. Seventy-six percent of surgeries were done in two high-volume hospitals (≥10 cases per year), while the remaining 24% were done in low-volume hospitals. Operative mortality was 12.0% and varied between 0 and 25.0% depending on the hospital. Variables that differed significantly between hospitals included patient age, the percentage of patients in shock, left ventricular ejection fraction, creatinine level, arterial cannulation site, brain protection technique, tobacco use, and intraoperative blood transfusion. The percentage of patients who underwent aortic valve repair or replacement procedures differed significantly between hospitals (p < 0.001), although the prevalence of moderate-to-severe aortic insufficiency was not significantly different (p = 0.14). There were no significant differences in clinical outcomes including mortality, renal failure, stroke, or gastrointestinal complications between hospitals or based on arterial cannulation site (all p > 0.05). Patients who had aortic cross-clamping or endovascualr repair had more embolic strokes when compared with patients who had hypothermic circulatory arrest (p = 0.03). Conclusion There remains considerable practice variation in Stanford Type A aortic dissection repair surgery within Maryland including some modifiable factors such as intraoperative blood transfusion, arterial cannulation site, and brain protection technique. Continued efforts are needed within MCSQI and nationally to evaluate and employ the best practices for patients having acute aortic dissection repair surgery.