Size-mismatched transplantation from large donors to small recipients is associated with pancreas graft thrombosis: A retrospective national observational study

Introduction: Donor–recipient (D/R) size mismatch has been evaluated for a number of organs but not for pancreas transplantation. Methods: We retrospectively evaluated 438 patients who had undergone pancreas transplantation. The D/R body surface area (BSA) ratio was calculated, and the relationship between the ratio and graft prognosis was evaluated. We divided the patients into two groups and evaluated graft survival. The incidence of pancreas graft thrombosis resulting in graft failure within 14 days and 1-year graft survival were compared using Kaplan–Meier curves, and the prognostic factors associated with graft thrombosis were identified by univariate and multivariate analyses. Results: The mean/median donor and recipient BSAs were 1.63 m²/1.65 m², and 1.57 m²/1.55 m², respectively; the mean and median D/R BSAs were both 1.05. The receiver operating characteristic curve cutoff for the D/R BSA ratio was 1.09, and significant differences were identified between patients with ratios of ≥1.09 (high group) versus <1.09 (low group). The incidence of graft thrombosis resulting in pancreas graft failure within 14 days was significantly higher in the high group than in the low group (p <.01). One-year overall and death-censored pancreas graft survival were significantly higher in the low group than in the high group (p <.01). Multivariate analysis identified recipient height, donor BSA, and donor hemoglobin A1c as significant independent factors for graft thrombosis. Cubic spline curve analysis indicated an increased risk of graft thrombosis with increasing D/R BSA ratio. Conclusion: D/R size mismatch is associated with graft thrombosis after pancreas transplantation.