Proposed Thresholds for Pancreatic Tissue-Volume for Safe Intraportal Islet-Autotransplantation after Total-Pancreatectomy

摘要

The simple question of how much tissue volume is really safe to infuse in TP-IAT for chronic pancreatitis precipitated this analysis. We examined a large cohort of CP patients (n=233) to determine major risk factors for elevated portal pressure during islet infusion, using bivariate and multivariate regression modeling. Rates of bleeding requiring operative intervention and portal venous thrombosis were evaluated. The total tissue volume per kg body weight infused intraportally was the best independent predictor of change in portal pressure (ΔPP) (p<0.0001; R²=0.566). Rates of bleeding and PVT were 7.73% and 3.43%, respectively. Both TV/kg and ΔPP are associated with increased complication rates, although ΔPP appears to be more directly relevant. ROC analysis identified an increased risk of PVT above a suggested cut-point of 26 cmH2O (AUC=0.759), which was also dependent on age. This ΔPP threshold was more likely to be exceeded in cases where the total TV >0.25 cc/kg. Based on this analysis, we have recommended targeting a TV <0.25cc/kg during islet manufacturing and to halt intraportal infusion, at least temporarily, if the ΔPP exceeds 25 cmH2O. These models can be used to guide islet manufacturing and clinical decision-making to minimize risks in TP-IAT recipients.