Evaluating Radiologic Metrics of Sarcopenia and Body Fat in Parastomal Hernia Development After Cystectomy and Ileal Conduit Urinary Diversion

The role of musculoskeletal metrics on the incidence of radiologic parastomal hernia (PSH) following cystectomy and ileal conduit (IC) urinary diversion is not well understood. We retrospectively reviewed the clinical data and preoperative CT scans of patients from the Prophylactic Use of Biologic Mesh in Ileal Conduit (PUBMIC) trial (#NCT02439060) to assess the relationship between sarcopenia and body fat metrics on the incidence of radiologic PSH following cystectomy and IC urinary diversion. We used Synapse 3D (Fujifilm, Stamford, CT) in a semiautomated fashion to extract visceral fat area (VFA), subcutaneous fat area (SFA), and waist circumference (WC) from CT scans at the levels of upper L3 and umbilicus. The psoas muscle was automatically measured at the level of L3 to assess sarcopenia via the lowest sex-specific quartile of the psoas muscle index (PMI: PMA/Ht²). 137 patients’ data were eligible to be analyzed from the PUBMIC trial for this study. Multivariable analysis indicated that SFA at the level of L3>220cm² (Q3) was significantly associated with an increased risk of PSH (HR: 2.5, 95% CI 1.2-5.2; P=0.01). No other significant associations between PSH development and other clinical and radiologic features were discovered. Nevertheless, utilizing Synapse 3D in a semiautomated fashion offers a method to investigate other radiologic factors that may impact the development of PSH and other oncological and non-oncological patient outcomes.