Frailty is a critical determinant of surgical outcomes in patients undergoing radical cystectomy for bladder cancer. Traditional frailty assessments rely on subjective clinical tools, whereas psoas muscle thickness (PMT), an imaging-based biomarker, offers an objective alternative. This study evaluates the association between preoperative PMT and postoperative outcomes in patients undergoing radical cystectomy.

This retrospective study included 18 patients who underwent cystectomy over a 2-year period. PMT was measured at the level of the fourth lumbar vertebra (L4) using preoperative CT scans. Patients were categorized into two groups based on PMT: ≤ 12 mm and > 12 mm. Frailty was assessed using the Comprehensive Geriatric Assessment or Charlson Comorbidity Index. Postoperative outcomes, including complications, length of stay, and 30-day mortality, were compared between groups. Data was analysed using Pearson’s correlation coefficient, independent t-tests, chi-square tests, and multivariate logistic regression.

The mean age of patients was 72 years, with a mean PMT of 14.2 mm. A significant negative correlation was found between PMT and frailty scores (r = -0.65, p = 0.03). Patients with PMT ≤ 12 mm had a higher incidence of postoperative complications (60% vs. 30%, p = 0.04) and longer hospital stays (12 vs. 7 days, p = 0.01). No significant difference was observed in 30-day mortality between groups. Multivariate analysis showed that lower PMT was independently associated with increased risk of postoperative complications (OR 3.5, 95% CI 1.2–10.4).

PMT ≤ 12 mm is a significant marker of frailty and is associated with worse postoperative outcomes in cystectomy patients. These findings suggest that PMT could be used as a preoperative tool to guide patient management in high-risk surgical populations.