Impact of Total Psoas Area and Lean Muscular Area on Mortality after Endovascular Aortic Aneurysm Repair

Abstract

Sarcopenia has assumed growing relevance as a morbimortality predictor after major abdominal surgery. The aim of this study is to access total psoas muscle area (TPA) and lean muscle area (LMA) impact in morbimortality after elective endovascular abdominal aortic aneurysm repair (EVAR). Asymptomatic patients submitted to aortic endoprosthesis implantation between January 1, 2014 and December 31, 2018 at our vascular surgery department were retrospectively evaluated. After exclusion criteria were applied, 105 patients were included in the study; preoperative computed tomography scans were evaluated using OSIRIX software (Bernex, Switzerland). Two observers independently calculated TPA at the most caudal level of the L3 vertebra and respective density, therefore calculating LMA. Patients were separated by tertiles with the lowest being considered sarcopenic and with higher muscle steatosis and compared with the higher tertiles. Patient demographics and intraoperative and postoperative period variables were collected. Charlson comorbidity index was calculated and surgical complications classified according to Clavien-Dindo. The intraclass correlation coefficient and Bland-Altman plot were made to characterize interobserver variability. Survival analysis was performed with the Kaplan-Meier method, and differences between survival curves were tested with the log-rank test. The effect of sarcopenia on patient survival was assessed using Cox proportional hazard models. Considering TPA, univariate analyses revealed that patients in the lower tertile had inferior survival (P=0.03), whereas multivariate analyses showed increased likelihood of mortality (P=0.039, hazard ratio (HR) 3.829). For LMA, univariate analyses revealed that patients in the lower tertile had inferior survival (P=0.013), whereas multivariate analyses showed increased likelihood of mortality (P=0.026, HR 4.153). When analyzing patients in the lowest tertile of both TPA and LMA, both univariate (P=0.002) and multivariate (P=0.018, HR 4.166) analyses reveled inferior survival. Our study reveals reduced survival in patients with low TPA and low LMA submitted to elective EVAR; these factors should probably be taken into consideration in the future for preoperative risk evaluation and surgical planning.