Preoperative Assessment of Muscle Mass Using Computerized Tomography Scans to Predict Outcomes Following Orthotopic Liver Transplantation.

Background: Sarcopenia is an established risk factor predicting survival in chronically ill and trauma patients. We herein examine the assessment and clinical implication of sarcopenia in liver transplantation (LT).

Methods: Computerized tomography scans from 172 patients waitlisted for LT were analyzed by applying 6 morphometric muscle scores, including 2 density indices (psoas density [PD] and skeletal muscle density [SMD]) and 4 scores based on muscle area (total psoas area, psoas muscle index, skeletal muscle area, and skeletal muscle index).

Results: The prevalence of sarcopenia in our cohort ranged from 7.0% to 37.8%, depending on the score applied. Only sarcopenia as defined by the density indices PD and SMD (but not total psoas area, psoas muscle index, skeletal muscle area, or skeletal muscle index) revealed clinical relevance since it correlates significantly with postoperative complications (≥Grade III, Clavien-Dindo classification) and sepsis. Furthermore, sarcopenia predicted inferior patient and graft survival, with low muscle density (PD: <38.5 HU or SMD: <30 HU) representing an independent risk factor in a multivariate regression model (P < 0.05). Importantly, the widely used Eurotransplant donor risk index had a predictive value in nonsarcopenic patients but failed to predict graft survival in patients with sarcopenia.

Conclusions: Sarcopenia revealed by low muscle density correlates with major complications following LT and acts as an independent predictor for patient and graft survival. Therefore, the application of a simple computerized tomography-morphologic index can refine an individual recipient's risk estimate in a personalized approach to transplantation.