Donor-recipient (D/R) size mismatch has been evaluated for a number of organs but not for pancreas transplantation. 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 14days 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. The mean/median donor and recipient BSAs were 1.63m2 /1.65m2 , and 1.57m2 /1.55m2 , 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 14days 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. D/R size mismatch is associated with graft thrombosis after pancreas transplantation.

Pancreas transplants from expanded criteria donors are performed widely in Japan because there is a shortage of brain-dead donors. However, the effectiveness of this strategy is unknown. We retrospectively studied 371 pancreas transplants to evaluate the possibility of pancreas transplantation from expanded criteria donors by the Pancreas Donor Risk Index (PDRI). Patients were divided into five groups according to quintiles of PDRI values (Q1-Q5). The 1-year pancreas graft survival rates were 94.5% for Q1, 91.9% for Q2, 90.5% for Q3, 89.3% for Q4, and 79.6% for Q5, and were significantly lower with a lower PDRI (p = 0.04). A multivariate analysis showed that the PDRI, donor hemoglobin A1c values, and pancreas transplantation alone significantly predicted 1-year pancreas graft survival (all p < 0.05). Spline curve analysis showed that the PDRI was incrementally associated with an increased risk of 1-year graft failure. In the group with a PDRI ≥ 2.87, 8/56 patients had graft failures within 1month, and all were due to graft thrombosis. The PDRI is a prognostic factor related to the 1-year graft survival rate. However, pancreas transplantation from high-PDRI donors shows acceptable results and could be an alternative when the donor pool is insufficient.

In cases after pancreas transplantation (PTx), the pancreas graft might be lost for various reasons, including a pancreatoduodenal graft-related complication or patient death with a functioning graft. Although the causes seem to have distinct characteristics, the causes of pancreas graft loss have not been characterized. This study aimed to characterize the causes of pancreas graft loss by analyzing data from a Japanese nationwide registry. This study included 391 patients who received simultaneous pancreas-kidney transplantation among 461 patients with PTx during the study period in approved institutions in Japan. We characterized each cause in terms of the timing of the cause-specific graft loss and preoperative factors associated with graft loss based on nationwide data from a Japanese nationwide registry. Among the 391 cases, 113 lost the pancreas graft due to patient death with a functioning graft (DWFG; n = 34, 44.2%), graft thrombus (n = 22, 28.6%), or chronic rejection (CR; n = 7, 9.1%). Average (± standard deviation) time from PTx to graft loss due to DWFG, graft thrombus, and CR was 3.70 ± 4.36, 0.02 ± 0.01, and 2.37 ± 2.08 years, respectively. Duration of type 1 diabetes mellitus and donor body mass index were significantly associated with pancreas graft loss due to DWFG and graft thrombus, respectively. This characterization showed that the timing and preoperative factors associated with pancreas graft loss were significantly different for different causes of graft loss. These results may inform PTx follow-up protocols to ensure that appropriate care is based on the cause of graft loss.

The feasibility of pancreas transplantation (PT) in older recipients remains a matter of debate. We examined the influence of recipient age on PT outcomes and identified the prognostic factors for older recipients. We compared the outcomes of PT in recipients aged < 50years (younger group; n = 285) with those in recipients aged ≥ 50years (older group; n = 94). Prognostic factors in the older group were analyzed by a logistic regression model and the influence of recipient age on survival outcomes were analyzed using propensity score matching. The patient survival rate was significantly worse in the older group (P < 0.001). Patient death from infection or/and multiple organ failure or cardiac/cerebrovascular events was also more frequent in the older group than in the younger group (P = 0.012 and P = 0.045, respectively). A longer duration of diabetes was an independent risk factor of 1-year mortality in the older group. In a propensity score-matched comparison, the older recipients (n = 77) had significantly poorer survival than the younger recipients (n = 77) (P = 0.026). PT should be considered with appropriate caution, especially for older recipients with a long duration of diabetes.

In Japan, it has been about 10years since the revision of the law on donating brain-dead organs. The present study compared the outcomes of pancreatic transplant before and after the revision of the law. The 437 patients who had received pancreas transplantation were divided into two groups according to the time when pancreas transplantation was performed between era 1 (before the revision) and 2 (after the revision), and compared in the patient and pancreas graft survival. While the annual number of brain-dead donors was <10 in era 1, and this number significantly increased in era 2 to >50. This resulted in an increased number of pancreas transplantations: >30 cases per year. The comparison data after a propensity score-matched analysis revealed that the death-censored pancreatic graft survival at 1, 3, and 5years after pancreas transplantation in era 2 was 94.9%, 92.0%, and 92.0%, which, while lacking significance, tended to be better than the values of 90.5%, 83.1%, and 78.2%, respectively, in era 1. The revision of the law on donating brain-dead organs increased the number of pancreas transplantations. Technical improvements in surgery due to increased experience with performing pancreas transplants may help improve pancreatic graft survival.

In Japan, 437 pancreas transplantations (PTx) were carried out between 2000 and 2019. Clinical data for all PTx cases are registered in the Japan Pancreas Transplant Registry of the Japan Society for Pancreas and Islet Transplantation. Here we analyzed the registry data to describe the current status of PTx in Japan. The 437 PTx included 410 from deceased donors (407 from brain‐dead and 3 from non‐heart‐beating donors) and 27 from living donors. We investigated the clinical characteristics of the 410 PTx from deceased donors. The rate of marginal donors using expanded donor criteria was higher in Japan than in other countries. At 1/5/10 years post‐PTx, the overall survival rates were 95.8%/94.2%/88.7%, and the graft survival rates were 85.9%/76.2%/67.4% for pancreas and 93.2%/90.8%/78.2% for kidney (non‐censored for death). These rates were comparable to those in other countries. When stratified by PTx category, survival was significantly better following simultaneous pancreas‐kidney transplantation (SPK) compared to pancreas‐after‐kidney transplantation (PAK) or PTx alone (PTA). Immunological rejection was more frequently the cause of graft loss in PAK/PTA cases than in SPK cases, potentially contributing to the poorer survival in PAK/PTA. These outcomes highlight two main concerns: substantial incidence of pancreas graft loss, and inferior outcomes after PAK/PTA. Overall, PTx outcome is favorable in Japan, despite the high rate of marginal donors. To improve outcomes, it is important to prevent and manage each cause of pancreas graft loss. Overcoming the poorer survival in PAK/PTA may require new immunosuppressive protocols or allogenic islet transplantation.

ObjectivesClinical impact of pancreas donor age on pancreas transplantation (PTx) outcome has not been well investigated. Here we analyzed the nationwide PTx registry in Japan to assess posttransplant outcomes in donor age-stratified groups. MethodsThis study included 410 cases of PTx performed in Japan between 2000 and 2019. Analyses were performed using clinical data from the Japan Pancreas Transplant Registry of Japan Society for Pancreas and Islet Transplantation. ResultsThe 410 PTx cases were classified based on donor age: <10 years (n = 10, 2.4%), 10–19 years (n = 30, 7.3%), 20–29 years (n = 64, 15.6%), 30–39 years (n = 75, 18.3%), 40–49 years (n = 114, 27.8%), 50–59 years (n = 90, 22.0%), and ≥60 years (n = 27, 6.6%). The incidence of early pancreas graft loss (8.9%, 36/410 cases) did not exhibit a significant linear correlation with donor age. Posttransplant pancreas graft survival (1-/3-/5-/10-year rates of 85.9%/80.6%/76.2%/67.4% among all cases) was also not significantly associated with donor age. ConclusionPancreas donor age was not significantly associated with posttransplant outcome. This finding supports the use of expanded criteria donors, with regards to pancreas donor age, for PTx in cases of type 1 diabetes mellitus.

In Japan, the first pancreas transplantation was performed in 1984 from a brain-dead donor; subsequently, however, the concept of brain death became a social issue. Thereafter, the "Organ Transplant Act", which enables brain-dead transplantation, was enacted in 1997, and then revised in 2010 so that donation after brain death became possible only with the consent of the family. Under the recipient selection and registration system developed after the enactment of the "Organ Transplant Act", more than 400 pancreas transplants have been carried out at facilities certified for brain-dead pancreas transplantation in Japan. Of the 410 total cadaveric pancreas transplants performed by the end of 2019, the patient survival and pancreatic and kidney graft survival rates were considered to be comparable to those in the United States and Europe despite the high frequency of marginal donors. Minimally invasive allogenic islet transplantation came to be covered by national health insurance in 2020 following good outcomes of a recent trial. Furthermore, to overcome the serious donor shortage in Japan, development of xenogeneic islet transplantation and regenerative medicine using stem cells is in progress, with xenotransplantation using porcine islets appearing particularly promising.

Background: The impact of pancreas transplantation, including kidney transplantation on patients’ life prognoses, is unclear in Japan. An analysis of the data of the Japan Pancreas Transplant Registry was performed to compare the patient survival between on the waiting list and after pancreas transplantation, and investigate the factors that affect the patient survival after pancreatic transplantation. Methods: The life prognoses of 361 patients who underwent pancreas transplantation from 2000 to December 2018 were examined. Results: The survival rates at 1, 5, and 10 years on the waiting list were 98.4%, 90.3%, and 78.1%, respectively, while those after transplantation were significantly improved (p = 0.029) at 100%, 97.5%, and 88.9%, respectively. Furthermore, the survival rates of patients waiting for simultaneous pancreas and kidney transplantation (SPK) at 1, 5, and 10 years were 98.2%, 89.4%, and 75.4%, respectively, while those after SPK were also significantly improved (p = 0.026) at 100%, 94.6%, and 88.8%. The multivariable analysis revealed that the duration of diabetes before surgery was the only independent risk factor (hazard ratio = 1.095, p = 0.012) that affected the patient survival after SPK. Conclusion: Pancreas transplantation was found to improve the life prognosis of patients with type 1 diabetes, especially those with end-stage renal failure waiting for SPK.

In Japan, about 30% of pancreatic transplant donors are ≥50years old, making them "extended-criteria donors (ECDs)." We analyzed 361 cases of transplantation involving donors from the Japanese pancreas transplantation registry to evaluate the acceptability of ECDs. The patient survival rates at 1, 5, and 10years after transplantation were 96.6%, 94.9%, and 88.3%, respectively. The survival rates of pancreas and kidney grafts at 1, 5, and 10years were 85.3%, 74.8%, and 70.6%, and 94.2%, 90.9%, and 80.9%, respectively. Multivariate analysis revealed that no particular donor factors significantly influenced the pancreatic graft survival. Patients were divided into 2 groups: donors ≥50years old (older group) and those <50years old (younger group). After propensity score matching, the overall pancreatic graft survival at 1, 5, and 10years after transplantation in the older group was 82.8%, 71.8%, and 69.5%, respectively, which was almost the same as in the younger group (84.9%, 70.2%, and 67.4%, respectively). No donor factors markedly influenced the pancreatic graft survival, and the outcomes of pancreas transplantation from ECDs ≥50years old were comparable to those from younger donors.