Psoas Muscle Mass can Predict Postsurgical Outcomes in Patients Who Undergo Radical Cystectomy and Urinary Diversion Reconstruction

Abstract

ObjectiveTo morphometrically measure to muscle mass which may reflect physical components of frailty. Hence, we evaluated the association between L4 total psoas area (TPA) and operative outcome after radical cystectomy (RC) for bladder cancer. MethodsIn a retrospective single-center study, bladder cancer patients who underwent RC and urinary diversion between 2007 and 2012 were enrolled. TPA was evaluated in the cross-sectional imaging. The psoas muscles were normalized with the height. Male patients with a psoas mass index ≤7.4 cm2/m2 and female patients with a psoas mass index ≤5.2 cm2/m2 were classified as sarcopenic. Outcome measures were 30- and 90-day readmission and complications, and survival. Multivariable logistic and Cox proportional-hazards regression models were used to determine relevant predictors. ResultsThe median age of the 441 participants and follow up time was 68 years (IQR 59-75) and 1.2 years (IQR 0.5-1.9), respectively. One hundred forty-three patients (32.4%) were sarcopenic. The 30-day readmission and the complication rates were 13.8% and 44.7%, respectively. The 90-day readmission and complication rates were 23.9% and 53.1%, respectively. The 1-year mortality rate was 11.6% (95%CI 8.7-15.4). Multivariable logistic regression analysis revealed an association between increased TPA and lower odds of 30-day complications after RC (OR 0.95, 95%CI 0.92-0.99, P = .02); similarly, an increase in TPA was of prognostic value, although not statistically significant in the multivariable model (P = .05) once adjusting for other patient factors. ConclusionSarcopenia predicted early complications and showed an informative trend for overall survival after RC, and thus may inform models predicting postsurgical outcomes.