Pancreas transplantation

Comprehensive review of imaging in pancreas transplantation: a primer for radiologists

Pancreas transplantation is a complex surgical procedure performed to restore normoglycemia in patients with type 1 diabetes and includes whole/segmental organ transplant and islet cell transplantation (ICT). In the United States, simultaneous pancreas-kidney transplant (SPK) is most commonly performed due to the higher occurrence of end-stage renal disease in diabetic patients. Understanding the surgical technique and postoperative anatomy is imperative for effective and accurate surveillance following transplantation. Imaging plays an essential role in patients with pancreatic transplants and is often used to evaluate viability, vascular and parenchymal anatomy, and identify potential complications. Imaging techniques such as ultrasound, color and spectral Doppler, computed tomography (CT), magnetic resonance imaging (MRI), and angiography have a complementary role in the postoperative evaluation following a pancreas transplant. The common complications after a whole organ pancreas transplant include vascular thrombosis, graft rejection, pancreatitis, and infections. Complications can be classified into vascular (partial or complete venous thrombosis, arterial thrombosis, stenosis or pseudoaneurysm), parenchymal (pancreatitis, graft rejection), and bowel-related or miscellaneous causes (bowel obstruction, anastomotic leak, and peripancreatic fluid collections). Islet cell transplantation is an innovative therapy for patients with type 1 diabetes. It involves isolating insulin-producing islet cells from donor pancreas and transplanting into recipients, to provide long-term insulin independence or significantly reduce insulin requirements. In recent years, isolation techniques, immunosuppressive regimens, and post-transplant monitoring advancements have propelled ICT as a viable therapeutic option. This comprehensive review aims to provide insights into the current state-of-the-art imaging techniques discussing both normal and abnormal features following pancreas transplantation.

Donor Blood Tests do Not Predict Pancreas Graft Survival After Simultaneous Pancreas Kidney Transplantation; a National Cohort Study

Simultaneous pancreas-kidney (SPK) transplantation improves quality of life and limits progression of diabetic complications. There is reluctance to accept pancreata from donors with abnormal blood tests, due to concern of inferior outcomes. We investigated whether donor amylase and liver blood tests (markers of visceral ischaemic injury) predict pancreas graft outcome using the UK Transplant Registry (2016-2021). 857 SPK recipients were included (619 following brainstem death, 238 following circulatory death). Peak donor amylase ranged from 8 to 3300 U/L (median = 70), and this had no impact on pancreas graft survival when adjusting for multiple confounders (aHR = 0.944, 95% CI = 0.754-1.81). Peak alanine transaminases also did not influence pancreas graft survival in multivariable models (aHR = 0.967, 95% CI = 0.848-1.102). Restricted cubic splines were used to assess associations between donor blood tests and pancreas graft survival without assuming linear relationships; these confirmed neither amylase, nor transaminases, significantly impact pancreas transplant outcome. This is the largest, most statistically robust study evaluating donor blood tests and transplant outcome. Provided other factors are acceptable, pancreata from donors with mild or moderately raised amylase and transaminases can be accepted with confidence. The use of pancreas grafts from such donors is therefore a safe, immediate, and simple approach to expand the donor pool to reach increasing demands.

Evaluating Global and Temporal Trends in Pancreas and Islet Cell Transplantation: Public Awareness and Engagement

BACKGROUND

Pancreas transplantation is a crucial surgical intervention for managing diabetes, but it faces challenges such as its invasive nature, stringent patient selection criteria, organ scarcity, and centralized expertise. Despite the steadily increasing number of pancreas transplants in the United States, there is a need to understand global trends in interest to increase awareness of and participation in pancreas and islet cell transplantation.

METHODS

We analyzed Google Search trends for "Pancreas Transplantation" and "Islet Cell Transplantation" from 2004 to 14 November 2023, assessing variations in search interest over time and across geographical locations. The Augmented Dickey-Fuller (ADF) test was used to determine the stationarity of the trends (p < 0.05).

RESULTS

Search interest for "Pancreas Transplantation" varied from its 2004 baseline, with a general decline in peak interest over time. The lowest interest was in December 2010, with a slight increase by November 2023. Ecuador, Kuwait, and Saudi Arabia showed the highest search interest. "Islet Cell Transplantation" had its lowest interest in December 2016 and a more pronounced decline over time, with Poland, China, and South Korea having the highest search volumes. In the U.S., "Pancreas Transplantation" ranked 4th in interest, while "Islet Cell Transplantation" ranked 11th. The ADF test confirmed the stationarity of the search trends for both procedures.

CONCLUSIONS

"Pancreas Transplantation" and "Islet Cell Transplantation" showed initial peaks in search interest followed by a general downtrend. The stationary search trends suggest a lack of significant fluctuations or cyclical variations. These findings highlight the need for enhanced educational initiatives to increase the understanding and awareness of these critical transplant procedures among the public and professionals.

The impact of time to death in donors after circulatory death on recipient outcome in simultaneous pancreas-kidney transplantation

The time to arrest donors after circulatory death is unpredictable and can vary. This leads to variable periods of warm ischemic damage prior to pancreas transplantation. There is little evidence supporting procurement team stand-down times based on donor time to death (TTD). We examined what impact TTD had on pancreas graft outcomes following donors after circulatory death (DCD) simultaneous pancreas-kidney transplantation. Data were extracted from the UK transplant registry from 2014 to 2022. Predictors of graft loss were evaluated using a Cox proportional hazards model. Adjusted restricted cubic spline models were generated to further delineate the relationship between TTD and outcome. Three-hundred-and-seventy-five DCD simultaneous kidney-pancreas transplant recipients were included. Increasing TTD was not associated with graft survival (adjusted hazard ratio HR 0.98, 95% confidence interval 0.68-1.41, P = .901). Increasing asystolic time worsened graft survival (adjusted hazard ratio 2.51, 95% confidence interval 1.16-5.43, P = .020). Restricted cubic spline modeling revealed a nonlinear relationship between asystolic time and graft survival and no relationship between TTD and graft survival. We found no evidence that TTD impacts pancreas graft survival after DCD simultaneous pancreas-kidney transplantation; however, increasing asystolic time was a significant predictor of graft loss. Procurement teams should attempt to minimize asystolic time to optimize pancreas graft survival rather than focus on the duration of TTD.

Multi-Centre UK Analysis of Simultaneous Pancreas and Kidney (SPK) Transplant in Recipients With Type 2 Diabetes Mellitus

90% of the UK diabetic population are classified as T2DM. This study aims to compare outcomes after SPK transplant between recipients with T1DM or T2DM. Data on all UK SPK transplants from 2003-2019 were obtained from the NHSBT Registry (n = 2,236). Current SPK transplant selection criteria for T2DM requires insulin treatment and recipient BMI < 30 kg/m2. After exclusions (re-transplants/ambiguous type of diabetes) we had a cohort of n = 2,154. Graft (GS) and patient (PS) survival analyses were conducted using Kaplan-Meier plots and Cox-regression models. Complications were compared using chi-squared analyses. 95.6% of SPK transplants were performed in recipients with T1DM (n = 2,060). Univariate analysis showed comparable outcomes for pancreas GS at 1 year (p = 0.120), 3 years (p = 0.237), and 10 years (p = 0.196) and kidney GS at 1 year (p = 0.438), 3 years (p = 0.548), and 10 years (p = 0.947). PS was comparable at 1 year (p = 0.886) and 3 years (p = 0.237) and at 10 years (p = 0.161). Multi-variate analysis showed comparable outcomes in pancreas GS (p = 0.564, HR 1.221, 95% CI 0.619, 2.406) and PS(p = 0.556, HR 1.280, 95% CI 0.563, 2.911). Comparable rates of common complications were demonstrated. This is the largest series outside of the US evaluating outcomes after SPK transplants and shows similar outcomes between T1DM and T2DM recipients. It is hoped dissemination of this data will lead to increased referral rates and assessment of T2DM patients who could benefit from SPK transplantation.

Challenges and opportunities in the islet transplantation microenvironment: a comprehensive summary of inflammatory cytokine, immune cells, and vascular endothelial cells

It is now understood that islet transplantation serves as a β-cell replacement therapy for type 1 diabetes. Many factors impact the survival of transplanted islets, especially those related to the microenvironment. This review explored microenvironmental components, including vascular endothelial cells, inflammatory cytokines, and immune cells, and their profound effects on post-islet transplantation survival rates. Furthermore, it revealed therapeutic strategies aimed at targeting these elements. Current evidence suggests that vascular endothelial cells are pivotal in facilitating vascularization and nutrient supply and establishing a new microcirculation network for transplanted islets. Consequently, preserving the functionality of vascular endothelial cells emerges as a crucial strategy to enhance the survival of islet transplantation. Release of cytokines will lead to activation of immune cells and production and release of further cytokines. While immune cells hold undeniable significance in regulating immune responses, their activation can result in rejection reactions. Thus, establishing immunological tolerance within the recipient's body is essential for sustaining graft functionality. Indeed, future research endeavors should be directed toward developing precise strategies for modulating the microenvironment to achieve higher survival rates and more sustained transplantation outcomes. While acknowledging certain limitations inherent to this review, it provides valuable insights that can guide further exploration in the field of islet transplantation. In conclusion, the microenvironment plays a paramount role in islet transplantation. Importantly, we discuss novel perspectives that could lead to broader clinical applications and improved patient outcomes in islet transplantation.

The role of efferocytosis and transplant rejection: Strategies in promoting transplantation tolerance using apoptotic cell therapy and/or synthetic particles

Recently, efforts have been made to recognize the precise reason(s) for transplant failure and the process of rejection utilizing the molecular signature. Most transplant recipients do not appreciate the unknown length of survival of allogeneic grafts with the existing standard of care. Two noteworthy immunological pathways occur during allogeneic transplant rejection. A nonspecific innate immune response predominates in the early stages of the immune reaction, and allogeneic antigens initiate a donor-specific adaptive reaction. Though the adaptive response is the major cause of allograft rejection, earlier pro-inflammatory responses that are part of the innate immune response are also regarded as significant in graft loss. The onset of the innate and adaptive immune response causes chronic and acute transplant rejection. Currently employed immunosuppressive medications have shown little or no influence on chronic rejection and, as a result, on overall long-term transplant survival. Furthermore, long-term pharmaceutical immunosuppression is associated with side effects, toxicity, and an increased risk of developing diseases, both infectious and metabolic. As a result, there is a need for the development of innovative donor-specific immunosuppressive medications to regulate the allorecognition pathways that induce graft loss and to reduce the side effects of immunosuppression. Efferocytosis is an immunomodulatory mechanism with fast and efficient clearance of apoptotic cells (ACs). As such, AC therapy strategies have been suggested to limit transplant-related sequelae. Efferocytosis-based medicines/treatments can also decrease the use of immunosuppressive drugs and have no detrimental side effects. Thus, this review aims to investigate the impact of efferocytosis on transplant rejection/tolerance and identify approaches using AC clearance to increase transplant viability.

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.

Mortality assessment for pancreas transplants in the United States over the decade 2008-2018

BACKGROUND

Pancreas transplant is the only treatment that establishes normal glucose levels for patients diagnosed with diabetes. However, since 2005, no comprehensive analysis has compared survival outcomes of: (1) Simultaneous pancreas-kidney (SPK) transplant; (2) Pancreas after kidney (PAK) transplant; and (3) Pancreas transplant alone (PTA) to waitlist survival.

AIM

To explore the outcomes of pancreas transplants in the United States during the decade 2008-2018.

METHODS

Our study utilized the United Network for Organ Sharing Standard Transplant Analysis and Research file. Pre- and post-transplant recipient and waitlist characteristics and the most recent recipient transplant and mortality status were used. We included all patients with type I diabetes listed for pancreas or kidney-pancreas transplant between May 31, 2008 and May 31, 2018. Patients were grouped into one of three transplant types: SPK, PAK, or PTA.

RESULTS

The adjusted Cox proportional hazards models comparing survival between transplanted and non-transplanted patients in each transplant type group showed that patients who underwent an SPK transplant exhibited a significantly reduced hazard of mortality [hazard ratio (HR) = 0.21, 95% confidence intervals (CI): 0.19-0.25] compared to those not transplanted. Neither PAK transplanted patients (HR = 1.68, 95%CI: 0.99-2.87) nor PTA patients (HR = 1.01, 95%CI: 0.53-1.95) experienced significantly different hazards of mortality compared to patients who did not receive a transplant.

CONCLUSION

When assessing each of the three transplant types, only SPK transplant offered a survival advantage compared to patients on the waiting list. PKA and PTA transplanted patients demonstrated no significant differences compared to patients who did not receive a transplant.

Peritransplant Varicosis After Simultaneous Pancreas and Kidney Transplantation Is an Uncommon Cause of Late-Onset and Recurrent Gastrointestinal Bleeding

Ectopic peritransplant varicosis represents an uncommon cause of late-onset gastrointestinal (GI) bleeding after simultaneous pancreas and kidney transplantation (SPK). We report on a 53-year-old female patient who suffered from recurrent upper GI bleeding seven years after SPK with persistent graft function. Upper endoscopy revealed perianastomotic angiodysplasias, treated by clipping and Argon-Plasma-Coagulation. Repeated endoscopy showed no signs of anastomotic ulcer. With persistent symptoms, computed tomography and angiography revealed extensive ectopic varicosis around the pancreas and duodenal graft. With no signs of portal hypertension, pancreas graft venous outflow impairment or arterio-venous fistula, the origin of variceal formation remained unknown. The extended finding did not allow for endovascular treatment by embolization. Surgery with extensive variceal ligation led to persistent cessation of hemorrhage and maintained stable graft function. In patients with unclear recurrent upper GI bleeding after SPK, one should consider ectopic peritransplant varicosis as an exceptional bleeding cause. If endoscopic treatments fail, angiography should be performed to rule out unusual causes of vascular complications. In case of extensive peritransplant varicosis, surgery may remain the only successful therapy, whenever possible including graft preservation in well-functioning grafts.

Metabolic Outcomes After Pancreas Transplant Alone From Donation After Circulatory Death Donors-The UK Transplant Registry Analysis

Extrapolating data from early DCD (donation after circulatory death) kidney transplantation, pancreas transplants from DCD grafts were feared to have worse metabolic outcomes. Hence, we aimed to address the question of pancreas transplant alone (PTA) from DCD donors-are our concerns justified? A UK transplant registry analysis of 185 PTA performed between 2005 and 2018 was done. All early graft losses (<3 months) were excluded to allow focus on the metabolic outcomes (HbA₁c, weight gain and incidence of secondary diabetic macrovascular complications). The aim was to compare the metabolic outcomes, rejection rates (including the need for steroids), patient and graft survival between DBD (Donation after brainstem death) and DCD groups. After excluding early graft losses, data from 162 PTA (DBD = 114 and DCD = 48) were analyzed. Body mass index of the donor was less in DCD group (DBD = 23.40 vs. DCD = 22.25, p = 0.006) and the rest of the baseline transplant characteristics were comparable. There were no significant differences in the HbA₁c, weight gain, rejection rate, and incidence of secondary diabetic macrovascular complications post-transplant between DBD and DCD recipients. The 1-, 5-, and 10-year patient and graft survival were similar in both the groups. PTA from DCD donors have equivalent metabolic outcomes and survival (patient/graft) as that of DBD donors.

Impact of Cytomegalovirus Infection and Disease on Graft Loss After Pancreas Transplantation: A Single-Institution Study in Japan

BACKGROUND

Cytomegalovirus (CMV) is one of the most frequent infections after pancreas transplantation (PTx), and it is unclear whether CMV infection is associated with pancreas graft loss. A limited number of studies about the relationship between CMV infection and pancreas graft loss have been reported from Western countries, but there have been no reports from Japan. This study investigated the relationship between CMV infection and pancreas graft loss after PTx in a single Japanese institution.

METHODS

This study included 58 patients who underwent PTx from deceased donors from April 2000 to March 2021 in our institution. We assessed pancreas graft loss based on CMV infection and disease and investigated the causes of graft loss, the time of onset of CMV disease, and the time of graft loss for each case.

RESULTS

The numbers of patients in the 4 categories of donor (D) and recipient (R) pretransplant anti-CMV antibody status were as follows: 4 (6.9%) in the D-/R- group, 6 (10.3%) in the D-/R+ group, 34 (58.6%) in the D+/R+ group, and 14 (24.1%) in the D+/R- group. Of the 58 patients, 74.1% and 44.1% received diagnoses of CMV infection and disease after PTx, respectively. There were no significant differences in the survival rates of pancreas graft loss stratified by CMV infection (P = .1809) or disease (P = .6241).

CONCLUSIONS

This study suggests that CMV infection and disease had no significant influence on pancreas graft loss in this Japanese institution.

Appraising pancreatic fistula in pancreas transplantation: A comprehensive complication index based analysis of postoperative outcomes and predictors of graft survival

BACKGROUND

A definition of pancreatic fistula specifically addressing pancreas transplantation (PT) is lacking. This study sought to characterize pancreatic fistula in this setting and to define its clinical relevance on the postoperative course and long-term graft survival (GS).

METHODS

Consecutive simultaneous pancreas and kidney transplantations were analysed. The global postoperative course was assessed through the comprehensive complication index (CCI). PF was defined according to the original International Study Group for Pancreatic Surgery (ISGPS) definition. Predictors of poor postoperative course and GS were explored.

RESULTS

Seventy-eight patients were analysed. Surgical morbidity was 48.7%, with severe complications occurring in 39.7%. Ninety-day mortality was 2.6%. PF occurred in 56.6% of patients, although its average clinical burden was low and did not correlate with either early or long-term outcomes. Peri-graft fluid collections, postoperative day (POD) 1 drain fluid amylase (DFA) ≥ 2200 U/L, and POD 5 DFA/serum amylase ratio ≥7.0 independently correlated with poor postoperative course. Perigraft fluid collections were associated with reduced GS.

CONCLUSION

Conventionally defined pancreatic fistula is frequent following PT, although its clinical impact is negligible. To define clinically relevant PF, novel cut-offs for DFA might be pondered in a future series, while perigraft fluid collections should be strongly considered.

Different timing and risk factors of cause-specific pancreas graft loss after simultaneous pancreas kidney transplantation

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.

Establishment of decellularized extracellular matrix scaffold derived from caprine pancreas as a novel alternative template over porcine pancreatic scaffold for prospective biomedical application

In this study, the caprine pancreas has been presented as an alternative to the porcine organ for pancreatic xenotransplantation with lesser risk factors. The obtained caprine pancreas underwent a systematic cycle of detergent perfusion for decellularization. It was perfused using anionic (0.5% w/v sodium dodecyl sulfate) as well as non-ionic (0.1% v/v triton X-100, t-octyl phenoxy polyethoxy ethanol) detergents and washed intermittently with 1XPBS supplemented with 0.1% v/v antibiotic and nucleases in a gravitation-driven set-up. After 48 h, a white decellularized pancreas was obtained, and its extracellular matrix (ECM) content was examined for scaffold-like properties. The ECM content was assessed for removal of cellular content, and nuclear material was evaluated with temporal H&E staining. Quantified DNA was found to be present in a negligible amount in the resultant decellularized pancreas tissue (DPT), thus prohibiting it from triggering any immunogenicity. Collagen and fibronectin were confirmed to be preserved upon trichrome and immunohistochemical staining, respectively. SEM and AFM images reveal interconnected collagen fibril networks in the DPT, confirming that collagen was unaffected. sGAG was visualized using Prussian blue staining and quantified with DMMB assay, where DPT has effectively retained this ECM component. Uniaxial tensile analysis revealed that DPT possesses better elasticity than NPT (native pancreatic tissue). Physical parameters like tensile strength, stiffness, biodegradation, and swelling index were retained in the DPT with negligible loss. The cytocompatibility analysis of DPT has shown no cytotoxic effect for up to 72 h on normal insulin-producing cells (MIN-6) and cancerous glioblastoma (LN229) cells in vitro. The scaffold was recellularized using isolated mouse islets, which have established in vitro cell proliferation for up to 9 days. The scaffold received at the end of the decellularization cycle was found to be non-toxic to the cells, retained biological and physical properties of the native ECM, suitable for recellularization, and can be used as a safer and better alternative as a transplantable organ from a xenogeneic source.

Recurrent Cytomegalovirus Infection Controlled by the Introduction of Everolimus in a Simultaneous Pancreas-Kidney Transplantation Recipient: A Case Report

In simultaneous pancreas-kidney transplantation (SPK) recipients, cytomegalovirus (CMV) infection is a major complication that has been associated with the use of tacrolimus (TAC)-based immunosuppression. As one of the immunosuppressive drug options, the use of mammalian target of rapamycin inhibitors (mTORi) results in reduced rates of CMV infection in the field of solid organ transplantation. However, little is known about mTORi usage in pancreas transplantation. We report a case of recurrent CMV infection that was controlled by the introduction of mTORi (everolimus) in addition to a TAC-based immunosuppression regimen in SPK. A 52-year-old man underwent SPK. Graft duodenal perforation occurred on the 13th day of surgery, and graft duodenal resection was performed after long-term abscess drainage treatment. After graft duodenal resection, he was diagnosed with CMV viremia, and valganciclovir was started. However, because of recurrent febrile neutropenia caused by cytopenia as a side effect of valganciclovir, there was a repeated need for granulocyte-colony stimulating factor treatment. Immunosuppressive drug taper adjustment was attempted to control recurrent CMV viremia, and everolimus was introduced with the aim of reducing the dose of TAC and mycophenolate mofetil. This resulted in a continuously negative CMV antigenemia test and a stable general condition. Understanding the characteristics of various immunosuppressive agents and appropriately controlling and managing infectious diseases is crucial for the good postoperative management of patients with SPK.

Endoscopic visualization of graft status in patients with pancreas transplantation

BACKGROUND

Enteric drainage into the recipient duodenum in pancreas transplantation (PT) can identify the graft duodenum by endoscopy. This study aimed to identify the characteristic endoscopic findings associated with graft failure or acute rejection in patients with PT.

METHODS

We reviewed the medical records of patients who underwent PT with duodenoduodenostomy (DD) between January 2015 and August 2019. During this period, there were 44 PTs with DD in 42 patients; 122 endoscopies were performed and analyzed.

RESULTS

Overall, pancreatic graft survival was 82% at a mean follow-up of 27 months (range 6-55 months). There were 8 graft failures and 10 acute rejections. In all 8 graft failures, a deep ulcer covered with fibrinous exudates of the graft duodenum was confirmed on endoscopy. Diffuse erythema inside the graft duodenum was observed in 8 of 10 acute rejections. The factors associated with acute rejection were elevated serum lipase level (OR 8.5, p = 0.02) and diffuse erythema inside the graft duodenum on endoscopy (OR 20.5, p < 0.01) in multivariate analysis.

CONCLUSIONS

In PT with DD patients, graft failure can be visualized by endoscopy, and diffuse erythema inside the graft duodenum may be a finding of acute rejection.

Comparing Outcomes and Cost Between Pancreas Transplant and Standard of Care in Patients With Type 1 Diabetes

OBJECTIVES

Pancreas transplant is the only treatment that establishes normal glucose levels for patients diagnosed with diabetes. We analyzed the outcome of pancreas transplant alone (PTA) versus standard of care in the United States from 2008 to 2018. We also developed an economic model to analyze the cost-effectiveness of pancreas transplant versus continuing standard of care.

METHODS

We used the Scientific Registry of Transplant Recipients database and analyzed PTA recipient survival. Using those results, we developed a Markov model that followed a cohort of 40-year-old patients with type 1 diabetes over a 10-year time horizon. The primary outcomes were (i) the survival benefit of a pancreas transplant, (ii) quality-adjusted life-years (QALYs), and (iii) total costs.

RESULTS

We found no difference in survival advantage of PTA compared with standard of care (hazard ratio, 1.09; 95% confidence interval, 0.56-2.14). However, pancreas transplant ($172,823, 6.87 QALY) was cost-saving compared with standard of care ($232,897, 6.04 QALY) for type 1 diabetes. Pancreas transplantation was cost-effective in 95% of 10,000 simulations in probabilistic sensitivity analysis, using a $100,000/QALY willingness-to-pay threshold.

CONCLUSIONS

Although there is no difference in survival for PTA compared with standard of care, PTA is a cost-saving therapy for type 1 diabetes.

Evaluation of the Efficacy and Effects of Common Hepatic Artery Reconstruction in Pancreas Transplantation: A Randomized Controlled Trial

Maintenance of postoperative graft flow is important in pancreas transplantation. In Japan, reconstruction of the common hepatic artery is performed primarily to increase perfusion in the pancreatic head. We investigated the effects of common hepatic artery reconstruction on patient and graft survival and endocrine functions. Twenty-nine cases of pancreas transplantation were registered in the clinical trial. Of the 29 cases, four were excluded because of the risk of ischemia without reconstruction or complicated reconstruction due to a narrow artery. A total of 25 cases were randomized into two groups: 13 in the non-reconstructed group and 12 in the reconstructed group. The 1-year patient survival and graft survival rates of the non-reconstructed and reconstructed groups were 92.3% and 83.3%, and 91.7% and 82.5%, respectively. The incidence of complications in the two groups was comparable, with 38.5% (5/13 cases) in the non-reconstructed group and 33.3% (4/12 cases) in the reconstructed group. The results of the glucagon stimulation test and oral glucose tolerance test at 1 month and 1 year post-transplantation were comparable. Common hepatic artery reconstruction is not essential unless there is risk of ischemia. This study was registered at the University Hospital Medical Information Network Clinical Trials Registry under UMIN000027213.

Influence of Intraoperative Hemodynamic Parameters on Outcome in Simultaneous Pancreas-Kidney Transplant Recipients

Objectives: Adequate organ perfusion, as well as appropriate blood pressure levels at the time of unclamping, is crucial for early and long-term graft function and outcome in simultaneous pancreas−kidney transplantation (SPKT). However, the optimal intraoperative mean arterial pressure (MAP) level has not well been defined. Methods: From a prospectively collected database, the medical data of 105 patients undergoing SPKT at our center were retrospectively analyzed. A receiver operating characteristic (ROC) analysis was preliminarily performed for optimal cut-off value for MAP at reperfusion, to predict early pancreatic graft function. Due to these results, we divided the patients according to their MAP values at reperfusion into <91 mmHg (n = 47 patients) and >91 mmHg (n = 58 patients) groups. Clinicopathological characteristics and outcomes, as well as early graft function and long-term survival, were retrospectively analyzed. Results: Donor and recipient characteristics were comparable between both groups. Rates of postoperative complications were significantly higher in the <91 mmHg group than those in the >91 mmHg group (vascular thrombosis of the pancreas: 7 (14%) versus 2 (3%); p = 0.03; pancreatitis/intraabdominal abscess: 10 (21%) versus 4 (7%); p = 0.03; renal delayed graft function (DGF): 11 (23%) versus 5 (9%); p = 0.03; postreperfusion urine output: 106 ± 50 mL versus 195 ± 45 mL; p = 0.04). There were no significant differences in intraoperative volume repletion, central venous pressure (CVP), use of vasoactive inotropic agents, and the metabolic outcome. Five-year pancreas graft survival was significantly higher in the >91 mmHg group (>91 mmHg: 82% versus <91 mmHg: 61%; p < 0.01). No significant differences were observed in patient and kidney graft survival at 5 years between both groups. Multivariate Cox regression analysis affirmed MAP < 91 mmHg as an independent prognostic predictor for renal DGF (HR 3.49, 1.1−10.8, p = 0.03) and pancreas allograft failure (HR 2.26, 1.0−4.8, p = 0.01). Conclusions: A MAP > 91 mmHg at the time point of reperfusion was associated with a reduced rate of postoperative complications, enhancing and recovering long-term graft function and outcome and thus increasing long-term survival in SPKT recipients.

Treating Type 1 Diabetes by Pancreas Transplant Alone: A Cohort Study on Actual Long-term (10 Years) Efficacy and Safety

BACKGROUND

Physiologically regulated insulin secretion and euglycemia are achievable in type 1 diabetes (T1D) by islet or pancreas transplantation. However, pancreas transplant alone (PTA) remains a debated approach, with uncertainties on its relative benefits and risks. We determined the actual long-term (10 y) efficacy and safety of PTA in carefully characterized T1D subjects.

METHODS

This is a single-center, cohort study in 66 consecutive T1D subjects who received a PTA between April 2001 and December 2007, and were then all followed until 10 y since transplant. Main features evaluated were patient survival, pancreas graft function, C-peptide levels, glycemic parameters, and the function of the native kidneys.

RESULTS

Ten-year actual patient survival was 92.4%. Optimal (insulin independence) or good (minimal insulin requirement) graft function was observed in 57.4% and 3.2% of patients, respectively. Six (9.0%) patients developed stage 5 or 4 chronic kidney disease. In the remaining individuals bearing a successful PTA, estimated glomerular filtration rate (eGFR) decline per year was -2.29 ± 2.69 mL/min/1.73 m2. Reduction of eGFR at 1 y post-PTA was higher in those with pre-PTA hyperfiltration and higher HbA1c concentrations; eGFR changes afterward significantly correlated with diabetes duration. In recipients with normoglycemia at 10 y, 74% of normoalbuminuric or microalbuminuric subjects pre-PTA remained stable, and 26% progressed toward a worse stage; conversely, in 62.5% of the macroalbuminuric individuals albuminuria severity regressed.

CONCLUSIONS

These long-term effects of PTA on patient survival, graft function, and the native kidneys support PTA as a suitable approach to treat diabetes in selected T1D patients.

Race does not predict pancreas graft failure after pancreas transplantation in the Modern Era

BACKGROUND

African-American (AA) has historically been associated with inferior graft survival after pancreas transplantation. However, with the improvement of immunosuppression and surgical technique, we hypothesized that the racial disparity has been neutralized.

METHODS

We analyzed data from the Scientific Registry of Transplant Recipients (1989-2018). Using Kaplan-Meier estimation and Cox proportional hazards regression, we examined the influence of race on pancreatic graft survival.

RESULTS

Before 2009, AA recipients had a higher risk of pancreatic graft failure after adjusting for confounding factors (hazard ratio [HR]: 1.16, 95% confidence interval [CI]: 1.08-1.24), but the risks for Hispanic and Asian recipients were both comparable to their Caucasian counterparts. However, the risk of pancreatic graft failure in AA recipients dropped to 1% and was no longer significant since 2009 (HR: 1.01, 95%CI: 0.88-1.16). Interestingly, donor race showed similar results. Furthermore, the concordance statistic of the complete pancreas donor risk index (including donor race) was 0.582, whereas the concordance did not change when donor race was eliminated from the model.

CONCLUSIONS

AA and other races have shown similar pancreatic graft survival in the modern era. Furthermore, donor racial disparity also seems neutralized; thus, donor race should not be considered as an indicator of pancreatic donor quality. This article is protected by copyright. All rights reserved.

Development and Application of a Semi quantitative Scoring Method for Ultrastructural Assessment of Acute Stress in Pancreatic Islets

Background.

Pancreas and islet transplantation outcomes are negatively impacted by injury to the endocrine cells from acute stress during donor death, organ procurement, processing, and transplant procedures. Here, we report a novel electron microscopy scoring system, the Newcastle Pancreas Endocrine Stress Score (NPESS).

Methods.

NPESS was adapted and expanded from our previously validated method for scoring pancreatic exocrine acinar cells, yielding a 4-point scale (0–3) classifying ultrastructural pathology in endocrine cell nuclei, mitochondria, endoplasmic reticulum, cytoplasmic vacuolization, and secretory granule depletion, with a maximum additive score of 15. We applied NPESS in a cohort of deceased organ donors after brainstem (DBD) and circulatory (DCD) death with a wide range of cold ischemic times (3.6–35.9 h) including 3 donors with type 1 and 3 with type 2 diabetes to assess islets in situ (n = 30) in addition to pancreata (n = 3) pre- and postislet isolation.

Results.

In DBD pancreata, NPESS correlated with cold ischemic time (head: r = 0.55; P = 0.02) and mirrored exocrine score (r = 0.48; P = 0.01). When stratified by endocrine phenotype, cells with granules of heterogeneous morphology had higher scores than α, β, and δ cells (P < 0.0001). Cells of mixed endocrine-exocrine morphology were observed in association with increased NPESS (P = 0.02). Islet isolation was associated with improved NPESS (in situ: 8.39 ± 0.77 [Mean ± SD]; postisolation: 5.44 ± 0.31; P = 0.04).

Conclusions.

NPESS provides a robust method for semiquantitative scoring of subcellular ultrastructural changes in human pancreatic endocrine cells in situ and following islet isolation with utility for unbiased evaluation of acute stress in organ transplantation research.

The MHC-characterized Miniature Swine: Lessons Learned From a 40-Year Experience in Transplantation

Over the last 40 y, a specialized herd of miniature swine has been intentionally bred to develop lines of animals homozygous for the swine major histocompatibility complex (MHC), which have facilitated transplantation studies across reproducible MHC and minor antigen mismatch barriers. These MHC-characterized miniature swine (Mc-MS) have been used for the study of novel surgical techniques, various approaches to tolerance induction of solid organ and vascularized composite allografts, as well as studies of the immunobiology of allografts and xenografts. Mc-MS possess characteristics that are highly advantageous to these studies, and their continued use will likely continue to play an important role in bridging "bench-to-cage-to bedside" therapies in the field of transplantation. In this review, we highlight the seminal contributions of the Mc-MS model to the field and analyze their role in the broader context of large animal models in transplantation research.

Effective Technique for Pancreas Transplantation by Iliac Vascular Transposition, Without Heparin-Based Anticoagulation Therapy

BACKGROUND

To evaluate patients undergoing a new procedure, iliac vascular transposition, in pancreas transplantation regarding the risk of thrombosis and graft survival without heparin-based anticoagulation therapy.

METHODS

Iliac vascular transposition (IVT) involves changing the positions of the external iliac artery and vein relative to each other. In this study, this technique was evaluated in patients undergoing the procedure compared with patients not undergoing the procedure (iliac vascular parallel (IVP) group).

RESULTS

No patients received prophylactic heparin therapy. Two patients in the IVP group (n = 26) developed complete thrombosis and six developed partial thrombosis, compared with no patients with complete thrombosis and one with partial thrombosis in the IVT group (n = 29). The cumulative incidence of thrombosis was significantly higher in the IVP group (p < 0.01). Cox regression revealed that not receiving iliac vascular transposition was the only significant risk factor for thrombosis (odds ratio: 10.1, 95% confidence interval: 1.27-81.2; p = 0.03). One-year graft survival was significantly better in the IVT group vs IVP group (p = 0.03).

CONCLUSIONS

IVT in pancreas transplantation is a simple technique that results in a lower thrombosis risk and better graft survival rates without heparin-based anticoagulation therapy.

A bioinspired scaffold for rapid oxygenation of cell encapsulation systems

Inadequate oxygenation is a major challenge in cell encapsulation, a therapy which holds potential to treat many diseases including type I diabetes. In such systems, cellular oxygen (O2) delivery is limited to slow passive diffusion from transplantation sites through the poorly O2-soluble encapsulating matrix, usually a hydrogel. This constrains the maximum permitted distance between the encapsulated cells and host site to within a few hundred micrometers to ensure cellular function. Inspired by the natural gas-phase tracheal O2 delivery system of insects, we present herein the design of a biomimetic scaffold featuring internal continuous air channels endowed with 10,000-fold higher O2 diffusivity than hydrogels. We incorporate the scaffold into a bulk hydrogel containing cells, which facilitates rapid O2 transport through the whole system to cells several millimeters away from the device-host boundary. A computational model, validated by in vitro analysis, predicts that cells and islets maintain high viability even in a thick (6.6 mm) device. Finally, the therapeutic potential of the device is demonstrated through the correction of diabetes in immunocompetent mice using rat islets for over 6 months.

Restoring normal islet mass and function in type 1 diabetes through regenerative medicine and tissue engineering

Type 1 diabetes is characterised by autoimmune-mediated destruction of pancreatic β-cell mass. With the advent of insulin therapy a century ago, type 1 diabetes changed from a progressive, fatal disease to one that requires lifelong complex self-management. Replacing the lost β-cell mass through transplantation has proven successful, but limited donor supply and need for lifelong immunosuppression restricts widespread use. In this Review, we highlight incremental advances over the past 20 years and remaining challenges in regenerative medicine approaches to restoring β-cell mass and function in type 1 diabetes. We begin by summarising the role of endocrine islets in glucose homoeostasis and how this is altered in disease. We then discuss the potential regenerative capacity of the remaining islet cells and the utility of stem cell-derived β-like cells to restore β-cell function. We conclude with tissue engineering approaches that might improve the engraftment, function, and survival of β-cell replacement therapies.

Challenges Associated with Pancreas and Kidney Retransplantation-A Retrospective Analysis

Simultaneous pancreas and kidney transplantation (SPK) is an accepted treatment for diabetic patients with renal failure, and is associated with increased survival and quality of life for recipients. There are only a few publications on the outcomes of simultaneous pancreas–kidney retransplantation (Re-SPK) after previous SPK and the loss of function of both grafts. A total of 55 patients with type 1 diabetes mellitus underwent pancreas retransplantation at our center between January 1994 and March 2021. Twenty-four of these patients underwent Re-SPK after a previous SPK. All 24 operations were technically feasible. Patient survival rate after 3 months, 1 year, and 5 years was 79.2%, 75%, and 66.7%, respectively. The causes of death were septic arterial hemorrhage (n = 3), septic multiorgan failure (n = 2), and was unknown in one patient. Pancreas and kidney graft function after 3 months, 1 year, and 5 years were 70.8% and 66.7%, 66.7% and 62.5%, and 45.8% and 54.2%, respectively. Relaparotomy was performed in 13 out of 24 (54.2%) patients. The results of our study show that Re-SPK, after previously performed SPK, is a technical and immunological challenge, associated with a significantly increased mortality and complication rate; therefore, the indication for Re-SPK should be very strict. Careful preoperative diagnosis is indispensable.

Impact of Early Pancreatic Graft Loss on Outcome after Simultaneous Pancreas-Kidney Transplantation (SPKT)-A Landmark Analysis

(1) Background: Simultaneous pancreas-kidney transplantation (SPKT) is a standard therapeutic option for patients with diabetes mellitus type I and kidney failure. Early pancreas allograft failure is a complication potentially associated with worse outcomes. (2) Methods: We performed a landmark analysis to assess the impact of early pancreas graft loss within 3 months on mortality and kidney graft survival over 10 years. This retrospective single-center study included 114 adult patients who underwent an SPKT between 2005 and 2018. (3) Results: Pancreas graft survival rate was 85.1% at 3 months. The main causes of early pancreas graft loss were thrombosis (6.1%), necrosis (2.6%), and pancreatitis (2.6%). Early pancreas graft loss was not associated with reduced patient survival (p = 0.168) or major adverse cerebral or cardiovascular events over 10 years (p = 0.741) compared to patients with functioning pancreas, after 3 months. Moreover, kidney graft function (p = 0.494) and survival (p = 0.461) were not significantly influenced by early pancreas graft loss. (4) Conclusion: In this study, using the landmark analysis technique, early pancreas graft loss within 3 months did not significantly impact patient or kidney graft survival over 10 years.

Pancreas transplantation perceptions and practice: Results from a national US survey

BACKGROUND

Due to a substantial decline in pancreas transplantation (PT) across the United States over the past 15 years, we sought to understand the perceptions and practices of US PT programs.

METHODS

Surveys were sent to members of the American Society of Transplantation Surgeons and the American Society of Transplantation by email and professional society postings between August 2019 and November 2019.

RESULTS

One hundred twenty three responses were recorded from 56 unique programs. Program characteristics were obtained from the Scientific Registry of Transplant Recipients. Respondents were transplant surgeons (71%), transplant nephrologists (17%), trainees (9%), and allied professionals (3%). Programs were defined according to annual volume as: low (<5 PT/year), intermediate (6-20), or high (>20). High-volume programs reported that these factors were most important for increased PT: expansion of recipient selection, more aggressive donor utilization, and hiring of PT program-specific personnel. At both the program and national level, the vast majority (82% and 79%, respectively) felt the number of PTs currently performed are not in balance with patients' needs.

CONCLUSIONS

Overall, programs reported that the option of PT is not offered adequately to diabetic patients and that strategies to maintain higher PT volume are most evident at intermediate, and especially, high-volume programs.

Current state of pancreas transplantation in Japan based on the nationwide registry

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.

Superporous agarose scaffolds for encapsulation of adult human islets and human stem-cell-derived β cells for intravascular bioartificial pancreas applications

Type 1 diabetic patients with severe hypoglycemia unawareness have benefitted from cellular therapies, such as pancreas or islet transplantation; however, donor shortage and the need for immunosuppression limits widespread clinical application. We previously developed an intravascular bioartificial pancreas (iBAP) using silicon nanopore membranes (SNM) for immunoprotection. To ensure ample nutrient delivery, the iBAP will need a cell scaffold with high hydraulic permeability to provide mechanical support and maintain islet viability and function. Here, we examine the feasibility of superporous agarose (SPA) as a potential cell scaffold in the iBAP. SPA exhibits 66-fold greater hydraulic permeability than the SNM along with a short (<10 μm) diffusion distance to the nearest islet. SPA also supports short-term functionality of both encapsulated human islets and stem-cell-derived enriched β-clusters in a convection-based system, demonstrated by high viability (>95%) and biphasic insulin responses to dynamic glucose stimulus. These findings suggest that the SPA scaffold will not limit nutrient delivery in a convection-based bioartificial pancreas and merits continued investigation.

Metabolic outcomes and renal function after simultaneous kidney/pancreas transplantation compared with kidney transplantation alone for type 2 diabetes mellitus patients

In this study, we aimed to compare the metabolic outcomes, renal function, and survival outcomes of simultaneous pancreas and kidney transplantation (SPK) and kidney transplantation alone (KTA) among end‐stage kidney disease (ESKD) patients with type II diabetes mellitus (T2DM). Patients with ESKD and T2DM who underwent KTA (n = 85) or SPK (n = 71) in a transplant center were retrospectively reviewed. Metabolic profiles, renal function, and survival outcomes were assessed repeatedly at different follow‐up time points. Propensity score procedures were applied to enhance between‐group comparability. The levels of renal and metabolic outcomes between SPK and KTA over time were examined and analyzed using mixed‐model repeated‐measures approaches. The median follow‐up period was 1.8 years. Compared with KTA, SPK resulted in superior metabolic outcomes and renal function, with lower levels of glycated hemoglobin (HbA1c; P = 0.0055), fasting blood glucose (P < 0.001), triglyceride (P = 0.015), cholesterol (P = 0.0134), low‐density lipoprotein (P = 0.0161), and higher estimated glomerular filtration rate (eGFR; P < 0.001). SPK provided better metabolic outcomes and renal function. The survival outcomes of the recipients and grafts were comparable between the two groups.

Impact of Recipient Age on Outcomes After Pancreas Transplantation

BACKGROUND

Few reports have provided the ages of pancreas transplant recipients. The aim of this study was to determine whether recipient age affects survival of pancreatic grafts after transplantation.

METHODS

We analyzed 73 patients who had undergone pancreas transplantation at our institution from August 2001 to March 2020 and assessed the effects of recipient age on pancreas graft survival within 5 years after pancreas transplantation.

RESULTS

The cutoff value for recipient age established by receiver operating characteristic curve was 35 years. The pancreas graft survival rate of recipients aged 35 years or younger (1, 3, and 5 years: 72.9%, 41.7%, and 41.7%, respectively) was significantly lower than that of recipients aged over 35 years (1, 3, and 5 years: 93.2%, 88.4%, and 88.4%, respectively). Multivariate Cox hazard regression analysis showed that recipient age 35 years or younger (hazard ratio = 3.60; 95% confidence interval, 1.04-12.50; P = .044) and solitary pancreas transplantation (hazard ratio = 10.72; 95% confidence interval, 2.72-42.28; P < .001) were significant risk factors for pancreas graft loss within 5 years.

CONCLUSION

Our data suggest that younger recipient age is a risk factor for pancreas graft loss after transplantation.

Pancreas preservation time as a predictor of prolonged hospital stay after pancreas transplantation

Objective

Length of hospital stay is a sensitive indicator of short-term prognosis. In this retrospective study, we investigated how pancreas preservation time affects length of hospital stay after pancreas transplantation.

Methods

Patients receiving pancreas transplantation (1998.7–2018.6) were identified from the Scientific Registry of Transplant Recipients database and grouped according to pancreas preservation time. We analyzed the relationship of pancreas preservation time with graft and patient survival and prolonged length of stay (PLOS; i.e., hospital stay ≥20 days).

Results

We included 18,099 pancreas transplants in the survival analysis. Pancreas preservation time >20 hours had a significantly higher risk of graft failure than 8 to 12 hours. Pancreas preservation time was not significantly associated with patient survival. We included 17,567 pancreas transplants in the analysis for PLOS. Compared with 8 to 12 hours, pancreas preservation time >12 hours had a significantly higher PLOS risk, which increased with increased pancreas preservation time. In simultaneous pancreas–kidney transplantation, we also found that pancreas preservation time was positively associated with PLOS risk with pancreas preservation time >12 hours.

Conclusion

Pancreas preservation time is a sensitive predictor of PLOS. Transplant centers should minimize pancreas preservation time to optimize patient outcomes.

Imaging in whole organ pancreatic transplants and a multimodality review of its complications

This pictorial review will describe the normal anatomy of whole organ pancreatic transplants and the common surgical variants with which the radiologist should be familiar. Complications may be divided into (1) vascular: arterial occlusion and stenosis, venous thrombosis, pseudoaneurysms and arteriovenous fistulae, (2) parenchymal complications such as pancreatitis and the variety of peripancreatic collections, and (3) enteric complications including leak and fistula formation. The radiologist plays a crucial role in the initial assessment of graft anatomy and perfusion, prompt diagnosis, and increasingly, in the management of complications.

The Value of Graft Implantation Sequence in Simultaneous Pancreas-Kidney Transplantation on the Outcome and Graft Survival

BACKGROUND/OBJECTIVES

The sequence of graft implantation in simultaneous pancreas-kidney transplantation (SPKT) warrants additional study and more targeted focus, since little is known about the short- and long-term effects on the outcome and graft survival after transplantation.

MATERIAL AND METHODS

103 patients receiving SPKT in our department between 1999 and 2015 were included in the study. Patients were divided according to the sequence of graft implantation into pancreas-first (PF, n = 61) and kidney-first (KF, n = 42) groups. Clinicopathological characteristics, outcome and survival were reviewed retrospectively.

RESULTS

Donor and recipient characteristics were similar. Rates of post-operative complications and graft dysfunction were significantly higher in the PF group compared with the KF group (episodes of acute rejection within the first year after SPKT: 11 (18%) versus 2 (4.8%); graft pancreatitis: 18 (18%) versus 2 (4.8%), p = 0.04; vascular thrombosis of the pancreas: 9 (14.8%) versus 1 (2.4%), p = 0.03; and delayed graft function of the kidney: 12 (19.6%) versus 2 (4.8%), p = 0.019). The three-month pancreas graft survival was significantly higher in the KF group (PF: 77% versus KF: 92.1%; p = 0.037). No significant difference was observed in pancreas graft survival five years after transplantation (PF: 71.6% versus KF: 84.8%; p = 0.104). Kidney graft survival was similar between the two groups. Multivariate analysis revealed order of graft implantation as an independent prognostic factor for graft survival three months after SPKT (HR 2.6, 1.3-17.1, p = 0.026) and five years (HR 3.7, 2.1-23.4, p = 0.040).

CONCLUSION

Our data indicates that implantation of the pancreas prior to the kidney during SPKT has an influence especially on the early-post-operative outcome and survival rate of pancreas grafts.

Pre-operative ankle-brachial index for cardiovascular risk assessment in simultaneous pancreas-kidney transplant recipients: a simple and elegant strategy!

Background

Patients with insulin-dependent diabetes mellitus type 1 (IDDM1) and end-stage kidney disease (ESKD) undergoing simultaneous pancreas kidney transplantation (SPKT) are a population with diffuse atherosclerosis and elevated risk of cardio- and cerebrovascular morbidity and mortality. We aimed to investigate the feasibility of preoperative screening for peripheral arterial disease (PAD), specifically ankle-brachial index (ABI) testing, to predict peri- and postoperative outcomes in SPKT recipients.

Methods

Medical data (2000–2016) from all patients with IDDM and ESKD undergoing SPKT at our transplant center were retrospectively analyzed. The correlation between PAD (defined by an abnormal ABI before SPKT and graft failure and mortality rates as primary end points, and the occurrence of acute myocardial infarction, cerebrovascular and peripheral vascular complications as secondary end points were investigated after adjustment for known cardiovascular risk factors.

Results

Among 101 SPKT recipients in our transplant population who underwent structured physiological arterial studies, 17 patients (17%) were diagnosed with PAD before transplantation. PAD, as defined by a low ABI index, was an independent and significant predictor of death (HR, 2.99 (95% CI 1.00–8.87), p = 0.049) and pancreas graft failure (HR, 4.3 (95% CI 1.24–14.91), p = 0.022). No significant differences were observed for kidney graft failure (HR 1.85 (95% CI 0.76–4.50), p = 0.178). In terms of the secondary outcomes, patients with PAD were more likely to have myocardial infarction, stroke, limb ischemia, gangrene or amputation (HR, 2.90 (95% CI 1.19–7.04), p = 0.019).

Conclusions

Pre-transplant screening for PAD and cardiovascular risk factors with non-invasive ABI testing may help to reduce perioperative complications in high-risk patients. Future research on long-term outcomes might provide more in depth insights in optimal treatment strategies for PAD among SPKT recipients.

Clinical impact of pancreas donor age on outcomes following pancreas transplantation: Analysis of a nationwide registry in Japan

OBJECTIVES

Clinical 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.

METHODS

This 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.

RESULTS

The 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.

CONCLUSION

Pancreas 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.

Influence of dialysis duration on outcomes of simultaneous pancreas-kidney transplant

OBJECTIVE

The objective of this study was to assess how pre-transplant dialysis duration affects transplant outcomes after simultaneous pancreas-kidney transplant (SPK) in patients with type 1 diabetes mellitus (T1DM).

METHODS

Data of 6887 T1DM patients who underwent SPK transplantation between 2008 and 2018 were obtained from the Scientific Registry of Transplant Recipients database. According to pre-transplant dialysis duration, the patients were divided into the preemptive SPK, 0-2 years, 2-5 years, and >5 years dialysis groups. Kaplan-Meier survival analysis was performed to compare patient and graft survival among the groups. Univariate and multivariate Cox regression analyses were used to identify predictors of transplant outcomes.

RESULTS

The mean follow-up period was 56.7 ± 34.7 months. Compared with no dialysis or preemptive SPK, dialysis for 0-2 years was not significantly associated with patient or kidney graft survival, while long-term dialysis of 2-5 years and >5 years was significantly associated with increased risk of death and kidney graft failure. However, the duration of dialysis was not associated with pancreas graft survival.

CONCLUSION

Long-term dialysis duration before SPK transplant is an independent predictor of patient death and kidney graft failure in T1DM patients.

Serum pancreatic enzymes in the early postoperative period predict complications associated with pancreatic fluid after pancreas transplantation: A retrospective, single-center, observational cohort study

BACKGROUND

Pancreas transplantation (PT) is a radical treatment for diabetes mellitus (DM). Although the results of PT have been improving, surgical complications remain. Few reports have focused on complications associated with pancreatic fluid (CAPF) after PT. We aimed to investigate the risk factors and predictors for CAPF after PT.

METHODS

Sixty-nine patients, who underwent deceased-donor PT for type 1 DM at our institution from August 2001 to May 2020, were retrospectively studied. We identified CAPF from those with Clavien-Dindo Classification ≥grade III and assessed risk factors by univariate and multivariate analyses using logistic regression.

RESULTS

Twenty-one (30.4%) patients had complications with Clavien-Dindo Classification ≥grade III. Eleven (16.0%) patients were diagnosed with CAPF. Median serum pancreatic amylase (P-AMY) levels with CAPF on postoperative day (POD)1 and POD2 were significantly higher than those without CAPF (P = .019 and P = .027, respectively). In multivariable analysis, serum P-AMY levels on POD1 were an independent predictive factor for CAPF (odds ratio 1.83, 95% confidence interval 1.07-3.14, P = .008).

CONCLUSIONS

Complications associated with pancreatic fluid after PT is associated with high serum P-AMY in the early postoperative period. Serum pancreatic enzymes in the first few postoperative days after PT may be a significant predictive factor for CAPF.

First-day plasma amylase detects patients at risk of complications after simultaneous pancreas-kidney transplantation

BACKGROUND

Simultaneous pancreas-kidney transplantation (SPK) carries a high risk of major postoperative complications, but knowledge on early warning signs and surrogate markers for postoperative complications is scarce.

AIMS

Our aim was to analyze the complication-predictive value of different laboratory tests in pancreas transplantation.

MATERIALS & METHODS

All SPKs in Finland between January 2010 and February 2020 were retrospectively analyzed. Levels of first three-day plasma amylase, drain fluid amylase, C-reactive protein, C-peptide, plasma trypsinogen, and white blood cell count were assessed for their performance predicting cumulative postoperative complications (assessed using the Comprehensive Complication Index) within 90 days from transplantation by using ROC analyses.

RESULTS

Of the 164 SPK patients included, 39 suffered at least one complication requiring laparotomy. First-day plasma amylase had the best value in predicting complications based on its high AUC value and easy clinical applicability, with an optimum cutoff of six times the upper normal limit. Negative predictive values (NPVs) and positive predictive values of this cutoff were 0.81 and 0.71 for any relaparotomy, and 0.91 and 0.71 for the Comprehensive Complication Index >47.7 (which equals the morbidity of two relaparotomies), respectively.

CONCLUSION

In conclusion, first-day plasma amylase could be able to detect patients at risk of complications after SPK.

Immunosuppression considerations in simultaneous organ transplant

Solid organ transplantation is a life-saving procedure for patients in the end stage of heart, lung, kidney, and liver failure. For patients with more than one failing organ, simultaneous organ transplantation has emerged as a viable treatment option. Immunosuppression strategies and outcomes for simultaneous organ transplant recipients have been reported, but often involve limited populations. Transplanting dual organs poses challenges in terms of balancing immunosuppression with immunologic risk and allograft damage from surgical complications. Furthermore, transplanting certain organs can impose considerations on the management of immunosuppression. For example, liver allografts may confer immunologic privilege and lower rates of rejection of other allografts. This review article evaluates immunosuppression strategies for simultaneous kidney-pancreas, liver-kidney, heart-kidney, heart-liver, heart-lung, lung-liver, and lung-kidney transplants. To date, no comprehensive review exists to address immunosuppressive strategies in simultaneous organ transplant populations. Our review summarizes the available literature and provides evidence-based recommendations regarding immunosuppression strategies in simultaneous organ transplant recipients.

Exploring new frontiers: Organ transplant anaesthesia or bariatric anaesthesia

Unlike previous years, Anaesthesiology today is a major speciality encompassing many areas of modern medicine. Advent of various surgical sub-specialities resulted into the emergence of anaesthesia sub-specialities, as every group of surgery has specific need. Choosing the best-suited speciality is a complex matter. For that, one needs to have an idea about each one of them. A postgraduate anaesthesiology student does not have adequate exposure to choose the speciality. This article will give an overview of two important sub-specialities i.e., Organ Transplant Anaesthesia and Bariatric Anaesthesia.

Immunosuppression trends in solid organ transplantation: The future of individualization, monitoring, and management

Immunosuppression regimens used in solid organ transplant have evolved significantly over the past 70 years in the United States. Early immunosuppression and targets for allograft success were measured by incidence and severity of allograft rejection and 1-year patient survival. The limited number of agents, infancy of human leukocyte antigen (HLA) matching techniques and lack of understanding of immunoreactivity limited the early development of effective regimens. The 1980s and 1990s saw incredible advancements in these areas, with acute rejection rates halving in a short span of time. However, the constant struggle to achieve the optimal balance between under- and overimmunosuppression is weaved throughout the history of transplant immunosuppression. The aim of this paper is to discuss the different eras of immunosuppression and highlight the important milestones that were achieved while also discussing this in the context of rational agent selection and regimen design. This discussion sets the stage for how we can achieve optimal long-term outcomes during the next era of immunosuppression, which will move from universal protocols to patient-specific optimization.

Sleeve gastrectomy enables simultaneous pancreas and kidney transplantation in severely obese recipients

BACKGROUND

Obesity adversely affects wait-listing and precludes patients with concomitant end-stage renal disease and type 1 diabetes mellitus from getting a simultaneous pancreas and kidney transplantation (SPK).

OBJECTIVE

To analyze safety and efficacy of laparoscopic sleeve gastrectomy (LSG) before SPK in severely obese type I diabetics.

METHODS

We assessed weight curve, complications, and graft function of three patients who underwent LSG before SPK.

RESULTS

LSG was uneventful in all patients. Body mass index dropped from 38.4 (range 35.7 - 39.9) before LSG to 28.5 (26.8 - 30.9) until SPK, with a mean loss of 25.8% (22.4 - 32.3). Interval between LSG and SPK was 364.3 (173 - 587) days. Pancreas and kidney graft function was excellent, with 100% insulin-free and dialysis-free survival over a mean follow-up of 3.6 (2.9 - 4.5) years. A1C dropped from 7% (6.3 - 8.2) before LSG to 4.9% (4.7 - 5.3) and 4.8% (4.5 - 5.1) 1 and 2 years after SPK, respectively.

CONCLUSION

LSG before SPK is safe and effective to enable severely obese type I diabetics to receive a lifesaving transplant. This is the first study analyzing the role of bariatric surgery before simultaneous pancreas and kidney transplantation.

Contrast-Enhanced Ultrasound Versus Doppler Ultrasound for Detection of Early Vascular Complications of Pancreas Grafts

OBJECTIVE. The purpose of this study is to compare conventional duplex ultrasound and contrast-enhanced ultrasound (CEUS) for identifying vascular abnormalities in pancreas allografts in the immediate posttransplant setting. Identification of pancreas allografts at risk of failure may impact patient care because early intervention for vascular insufficiency can lead to graft salvage. MATERIALS AND METHODS. Two radiologists who were blinded to patient outcomes performed a retrospective analysis of the postoperative Doppler ultrasound and CEUS images of 34 pancreas grafts from transplants performed between 2017 and 2019. A total of 28 patients who did not require surgical reexploration were considered the control group. Six patients had surgically proven arterial or venous abnormalities on surgical reexploration. Each radiologist scored grafts as having normal or abnormal vascularity on the basis of image sets obtained using Doppler ultrasound only and CEUS only. Comparisons of both the diagnostic performance of each modality and interobserver agreement were performed. RESULTS. Both readers showed that CEUS had increased sensitivity for detecting vascular abnormalities (83.3% for both readers) compared with Doppler ultrasound (66.7% and 50.0%). For both readers, the specificity of CEUS was similar to that of Doppler imaging (81.6% and 78.9% for reader 1 and reader 2 versus 76.3% and 84.2% for reader 1 and reader 2). For both readers, the negative predictive value of CEUS was higher than that of Doppler ultrasound (96.9% and 96.8% for reader 1 and reader 2 versus 93.5% and 91.4% for reader 1 and reader 2). Interobserver agreement was higher for CEUS than for Doppler ultrasound (κ = 0.54 vs κ = 0.28). CONCLUSION. CEUS may provide radiologists and surgeons with a means of timely and effective evaluation of pancreas graft perfusion after surgery, and it may help identify grafts that could benefit from surgical salvage.

Impact of pre-transplant dialysis modality on the outcome and health-related quality of life of patients after simultaneous pancreas-kidney transplantation

Background

Simultaneous pancreas-kidney transplantation (SPKT) profoundly improves the health-related quality of life (HRQoL) of recipients. However, the influence of the pre-transplant dialysis modality on the success of the SPKT and post-transplant HRQoL remains unknown.

Methods

We analyzed the surgical outcome, long-term survival, as well as HRQoL of 83 SPKTs that were performed in our hospital between 2000 and 2016. Prior to transplant, 64 patients received hemodialysis (HD) and nineteen patients received peritoneal dialysis (PD). Physical and mental quality of life results from eight basic scales and the physical and mental component summaries (PCS and MCS) were measured using the Short Form 36 (SF-36) survey.

Results

Peri- and postoperative complications, as well as patient and graft survival were similar between the two groups. Both groups showed an improvement of HRQoL in all SF-36 domains after transplantation. Compared with patients who received HD before transplantation, PD patients showed significantly better results in four of the eight SF-36 domains: physical functioning (mean difference HD - PD: − 12.4 ± 4.9, P = < 0.01), bodily pain (− 14.2 ± 6.3, P < 0.01), general health (− 6.3 ± 2.8, P = 0.04), vitality (− 6.8 ± 2.6, P = 0.04), and PCS (− 5.2 ± 1.5, P < 0.01) after SPKT. In the overall study population, graft loss was associated with significant worsening of the HRQoL in all physical components (each P < 0.01).

Conclusions

The results of this analysis show that pre-transplant dialysis modality has no influence on the outcome and survival rate after SPKT. Regarding HRQoL, patients receiving PD prior to SPKT seem to have a slight advantage compared with patients with HD before transplantation.

Islet-Like Structures Generated In Vitro from Adult Human Liver Stem Cells Revert Hyperglycemia in Diabetic SCID Mice

A potential therapeutic strategy for diabetes is the transplantation of induced-insulin secreting cells. Based on the common embryonic origin of liver and pancreas, we studied the potential of adult human liver stem-like cells (HLSC) to generate in vitro insulin-producing 3D spheroid structures (HLSC-ILS). HLSC-ILS were generated by a one-step protocol based on charge dependent aggregation of HLSC induced by protamine. 3D aggregation promoted the spontaneous differentiation into cells expressing insulin and several key markers of pancreatic β cells. HLSC-ILS showed endocrine granules similar to those seen in human β cells. In static and dynamic in vitro conditions, such structures produced C-peptide after stimulation with high glucose. HLSC-ILS significantly reduced hyperglycemia and restored a normo-glycemic profile when implanted in streptozotocin-diabetic SCID mice. Diabetic mice expressed human C-peptide and very low or undetectable levels of murine C-peptide. Hyperglycemia and a diabetic profile were restored after HLSC-ISL explant. The gene expression profile of in vitro generated HLSC-ILS showed a differentiation from HLSC profile and an endocrine commitment with the enhanced expression of several markers of β cell differentiation. The comparative analysis of gene expression profiles after 2 and 4 weeks of in vivo implantation showed a further β-cell differentiation, with a genetic profile still immature but closer to that of human islets. In conclusion, protamine-induced spheroid aggregation of HLSC triggers a spontaneous differentiation to an endocrine phenotype. Although the in vitro differentiated HLSC-ILS were immature, they responded to high glucose with insulin secretion and in vivo reversed hyperglycemia in diabetic SCID mice.