Clinical Variables Associated With Islet Yield and Long-Term Metabolic Outcomes following Total Pancreatectomy With Islet Autotransplantation

OBJECTIVES: Total pancreatectomy with islet autotransplantation (TPIAT) alleviates pain in chronic pancreatitis but is associated with significant metabolic consequences. This study evaluates factors associated with islet yield and their relationship with glycaemic outcomes in a single-centre UK cohort. METHODS: A retrospective analysis was performed of 80 consecutive patients undergoing TPIAT between 1994 and 2024. Variables included age, body mass index (BMI), prior pancreatic surgery, and symptom duration. Islet yield was quantified as islet equivalents (IEQ) and stratified as low (<150,000), intermediate (150,000-300,000), or high (>300,000). Glycaemic outcomes-insulin independence, C-peptide positivity (>0.1 nmol/L), and HbA1c-were assessed at a median follow-up of 36 months (range 24-60). Associations were analysed using Mann-Whitney U and Chi-square tests, with multivariate logistic regression. RESULTS: Median age of the cohort was 43 years (range 16-65). Median islet yield was 203,000 IEQ (range 7,596-1,057,488). Insulin independence was achieved in 73% of high-yield patients, compared with 31% of intermediate- and 10% of low-yield patients (P<0.001). C-peptide positivity was observed in 59% of low-yield, 86% of intermediate-yield, and 86% of high-yield patients. Median HbA1c values were 5.5%, 6.5%, and 7.5% in high-, intermediate-, and low-yield groups, respectively (P<0.001). On multivariate analysis, high islet yield independently predicted insulin independence (odds ratio 7.8, 95% CI 2.6-23.5; P<0.001), together with younger age and lower BMI. CONCLUSIONS: Islet yield is a key determinant of long-term metabolic outcomes following TPIAT. Although the primary indication for surgery remains pain relief, patient factors including age, BMI, prior pancreatic surgery, and duration of symptoms influence islet yield and can help inform expectations for postoperative glycaemic outcomes. Notably, shorter symptom duration was associated with higher islet yield, supporting timely evaluation and referral for TPIAT before further pancreatic interventions that may compromise islet recovery.