Pre-operative Sarcopenia Predicts Low Islet Cell Yield Following Total Pancreatectomy with Islet Autotransplantation for Chronic Pancreatitis

Background and Aim Sarcopenia defined as degenerative loss of skeletal muscle mass associated with aging, represents an objective parameter to measure frailty and to estimate patient's physiologic reserves. It is a robust predictor of post-operative complications in transplantation and major oncologic surgeries. There is no data regarding the prevalence of sarcopenia in chronic pancreatitis or its impact on the outcome of patients undergoing TPIAT for CP. We sought to estimate the prevalence of sarcopenia, its impact on post-operative morbidity and prediction of islet yield and metabolic outcomes in patients undergoing TPIAT. Methods Adult patients undergoing TPIAT between 2008 and 2018 were identified from our prospectively maintained database and were included if they had CT within 6 months before TPIAT. Skeletal muscle index (SMI) was evaluated by pre-operative CT at the level of L3 vertebra. Sarcopenia was defined as SMI < 52.4 in males and < 38.5 in females. Post-operative morbidity occurring within 90 days after TPIAT was graded as per the validated Clavien-Dindo score. Major post-surgical morbidity was defined as Clavien-Dindo score of IIIa or more. The yield of islets was quantified as islet equivalents (IEQ) and IEQ/kg recipient body weight was calculated. Results One hundred and thirty-eight patients underwent TPIAT, with 46 (one-third) being classified as having pre-operative sarcopenia based on CT. No significant differences were observed in the incidence of any major surgical complications, length of hospital stay (median (range in days) 11(1-8)vs. 12(2-9);p = 0.6) and 30-day readmission rate (7 (15.2%) vs, 2 (2.2%);p = 0.5) between sarcopenic and non-sarcopenic patients. More patients with sarcopenia needed to be discharged to residential rehabilitation facility compared with non-sarcopenic patients (7 (15.2%) vs. 2 (2.2%),p = 0.007). Sarcopenia (OR 7.4 (95% CI 1.32-41.24);p = 0.023) and presence of calcification (OR 5.5 (95% CI 0.94-32.19);p = 0.05) were independent predictors of low islet yield (< 2500 IEQ/kg) on multivariate analysis. Conclusion Sarcopenia is frequent in CP patients undergoing TPIAT, but not readily recognized by standard anthropometric measurement. Sarcopenia was associated with increased chance of discharge to a residential rehabilitation facility and with a poor islet yield during TPIAT. It is therefore critical to optimize nutrition prior to TPIAT surgery in CP patients.