"Pancreatic Calcification and Pathologic Fibrosis Score: Correlation with Islet Yield and Insulin Independence after Total Pancreatectomy with Islet Autotransplantation TPIAT".

Abstract

Objectives: Total pancreatectomy with islet autotransplantation (TPIAT) is offered to patients with advanced chronic pancreatitis even with calcified and fibrotic glands yet rarely are these manifestations of chronic pancreatitis objectively quantified and correlated with subsequent islet yield and endocrine outcomes after surgery.

Methods: All patients who underwent TPIAT at a single-institution between 2018 and 2024 were included. Preoperative computed tomography (CT) imaging was reviewed and scored for the distribution and severity of pancreatic calcification burden. All pathologic specimens were scored based on degree of fibrosis severity. Bivariate linear regression and logistic regression were performed to assess the relationship between clinical, radiographic, and pathologic variables with islet yield and insulin independence.

Results: Thirty two patients met inclusion criteria. Median total fibrosis score was 9. Four patients (13%) had mild (total fibrosis score ≤6), 14 (47%) had moderate (score 7-9), and 12 (40%) had severe (score 10-12) fibrosis. On univariable analysis of factors associated with islet yield (IEQ/kg), increasing calcification burden in the pancreatic head [Linear Estimate (LE): -783 IEQ/kg, 95% Confidence Interval (CI): -1,529, -37, P=0.040] and pancreatic body/tail [LE: -1,152 IEQ/kg, 95% CI: (-1,748, -557), P<0.001] were both associated with reduced islet yield. Increasing total fibrosis score [LE: -426 IEQ/kg, 95% CI (-730, -123), P=0.008] was also associated with reduced islet yield on unadjusted analysis. After adjusting for covariates, only increasing calcification burden in the pancreatic body/tail remained a significant predictor of islet yield [Beta Coefficient: -1,511 IEQ/kg (95% CI: -2,252 - -770, P<0.001). At time of discharge, 15 patients (47%) were insulin independent, and at 1 year, 9 (28%) remained independent.

Conclusion: Increasing severity of calcification burden in the pancreatic body/tail was associated with around 1500 IEQ/kg reduction in islet yield following TPIAT for chronic pancreatitis. The presence of pancreatic head calcifications may be associated with more favorable islet yield.