Effect of Low Skeletal Muscle Mass on Post-operative Survival of Patients With Abdominal Aortic Aneurysm: A Prognostic Factor Review and Meta-Analysis of Time-to-Event Data.

Abstract

OBJECTIVE/BACKGROUND\nLow psoas muscle mass is associated with increased mortality and morbidity after surgery. Recent evidence has linked low psoas muscle mass with survival after abdominal aortic aneurysm (AAA) repair. The aim of this study was to investigate the prognostic role of low skeletal muscle mass in survival of patients with AAA undergoing open or endovascular aneurysm repair (EVAR).\n\n\nMETHODS\nA review of the literature was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO registration number: CRD42018107793). The prognostic factor of interest was degenerative loss of skeletal muscle. A time-to-event data meta-analysis was performed for all cause mortality using the inverse variance method and the results were reported as summary hazard ratio (HR) and 95% confidence interval (CI). Pooled estimates of peri-operative outcome data were calculated using the odds ratio (OR) or risk difference (RD) and 95% CI. Random-effects models of meta-analysis were applied.\n\n\nRESULTS\nSeven observational cohort studies reporting a total of 1,440 patients were eligible for quantitative synthesis. Patients with low skeletal muscle mass had a significantly higher hazard of mortality than those without low skeletal muscle mass (HR 1.66, 95% CI 1.15-2.40; p\xa0=\xa0.007). Subgroup analysis including only patients who underwent EVAR showed a marginal survival benefit for patients without low skeletal muscle mass (HR 1.86, 95% CI 1.00-3.43; p\xa0=\xa0.05). Meta-analysis of two studies found no significant difference in peri-operative mortality (RD 0.04, 95% CI -0.13 to 0.21) and morbidity (OR 1.58, 95% CI 0.90-2.76; p\xa0=\xa0.11) between patients with and without low skeletal muscle mass.\n\n\nCONCLUSION\nThere is a significant link between low skeletal muscle mass and mortality in patients undergoing AAA repair. Prospective studies validating the use of body composition for risk prediction after aortic surgery are required before this tool can be used to support decision making and patient selection.