Pancreas Transplantation in the Modern Era

Single-center retrospective assessment of robotic-assisted simultaneous pancreas-kidney transplants: Exploring clinical utility

The diabetic population is witnessing a rise in obesity rates, creating specific hurdles for individuals seeking pancreas transplantation because they are frequently disqualified due to their elevated body weight. Introducing a robotic-assisted approach to transplantation has been proven to yield improved outcomes, particularly in patients with obesity. A retrospective analysis was conducted between January 2015 and September 2023. The study included a total of 140 patients, with 16 receiving robotic-assisted simultaneous pancreas-kidney transplantation (RSPK) and 124 undergoing open approach simultaneous pancreas-kidney transplantation (OSPK) during the study period. The median age was 45 (36.8-52.7) and 44.5 years (36.8-51.8) (RSPK vs OSPK, P = .487). There were no significant differences in demographics except body mass index (RSPK vs OSPK, 34.9 vs 28.1, P < .001) and a higher percentage of patients with high cardiac risk in the RSPK group. The robotic approach has a lengthier overall operative time and warm ischemia time. Surgical and nonsurgical complications at 30-days and 1-year grafts and patient survival (93.8% vs 96.8%, RSPK vs OSPK, P = .521) were similar. Our findings suggest that employing robotic assistance in simultaneous pancreas-kidney transplantation is safe. Wider adoption and utilization of this technique could potentially improve transplant accessibility for individuals with obesity and diabetes.

Pancreas Transplantation: Current Challenges, Considerations, and Controversies

Pancreas transplantation (PTx) reestablishes an autoregulating source of endogenous insulin responsive to normal feedback controls. In addition to achieving complete β-cell replacement that frees the patient with diabetes from the need to monitor serum glucose and administer exogenous insulin, successful PTx provides counterregulatory hormone secretion and exocrine function. A functioning PTx mitigates glycemic variability, eliminates the daily stigma and burden of diabetes, restores normal glucose homeostasis in patients with complicated diabetes, and improves quality of life and life expectancy. The tradeoff is that it entails a major surgical procedure and requisite long-term immunosuppression. Despite the high likelihood of rendering patients euglycemic independent of exogenous insulin, PTx is considered a treatment rather than a cure. In spite of steadily improving outcomes in each successive era coupled with expansion of recipient selection criteria to include patients with a type 2 diabetes phenotype, a decline in PTx activity has occurred in the new millennium related to a number of factors including: (1) lack of a primary referral source and general acceptance by the diabetes care community; (2) absence of consensus criteria; and (3) access, education, and resource issues within the transplant community. In the author's experience, patients who present as potential candidates for PTx have felt as though they needed to circumvent the conventional diabetes care model to gain access to transplant options. PTx should be featured more prominently in the management algorithms for patients with insulin requiring diabetes who are failing exogenous insulin therapy or experiencing progressive diabetic complications regardless of diabetes type. Furthermore, all patients with diabetes and chronic kidney disease should undergo consideration for simultaneous pancreas-kidney transplantation independent of geography or location.

Modern indications for referral for kidney and pancreas transplantation

PURPOSE OF REVIEW

Pancreas transplantation (PTx) is currently the only therapy that can predictably achieve sustained euglycemia independent of exogenous insulin administration in patients with insulin-dependent diabetes mellitus. This procedure involves a complex abdominal operation and lifetime dependence on immunosuppressive medications. Therefore, PTx is most frequently performed in combination with other organs, usually a kidney transplant for end stage diabetic nephropathy. Less frequently, solitary PTx may be indicated in patients with potentially life-threatening complications of diabetes mellitus. There remains confusion and misperceptions regarding indications and timing of patient referral for PTx.

RECENT FINDINGS

In this review, the referral, evaluation, and listing process for PTx is described, including a detailed discussion of candidate assessment, indications, contraindications, and outcomes.

SUMMARY

Because the progression of diabetic kidney disease may be less predictable than other forms of kidney failure, early referral for planning of renal and/or pancreas transplantation is paramount to optimize patient care and allow for possible preemptive transplantation.

Early Increases in Posttransplant Pancreatic Enzymes Are Associated With Surgical Complications But Not Graft Failure Among Pancreas Transplant Recipients

OBJECTIVES

This study aimed to find the association between immediate postoperative increases in pancreatic enzymes and posttransplant complications among pancreas transplant recipients (PTRs).

METHODS

We analyzed all PTRs transplanted at the University of Wisconsin between June 2009 and September 2018. Enzyme levels were presented as a ratio of absolute numbers to the upper limit of normal value, with value >1 considered as abnormal. We specifically evaluated bleeding, fluid collections, and thrombosis complications based on the amylase or lipase ratios on day 1 (Amylase1, Lipase1) and maximum ratios within 5 days of transplant (Amylasemax, Lipasemax). For early complications, we focused on technical complications that occurred within 90 days of transplant. For long-term outcomes, we assessed patient and graft survival, and rejections.

RESULTS

There were a total of 443 PTRs, 287 were simultaneous pancreas and kidney recipients, and 156 were solitary pancreas recipients. Higher Amylase1, Liplase1, Amylasemax, and Lipasemax were associated with an increase in early complications, mainly need for pancreatectomy, fluid collections, bleeding complications, or graft thrombosis, particularly in the solitary pancreas group.

CONCLUSIONS

Our finding suggests that cases of early perioperative enzyme increase merit consideration for early imaging investigation to mitigate detrimental outcomes.

Improved surgical outcomes following simultaneous pancreas-kidney transplantation in the contemporary era

BACKGROUND

Complications leading to early technical failure have been the Achilles' heel of simultaneous pancreas-kidney transplantation (SPKT). The study purpose was to analyze longitudinally our experience with early surgical complications following SPKT with an emphasis on changes in practice that improved outcomes in the most recent era.

STUDY DESIGN

Single center retrospective review of all SPKTs from 11/1/01 to 8/12/20 with enteric drainage. Early relaparotomy was defined as occurring within 3 months of SPKT. Patients were stratified into two sequential eras: Era 1 (E1): 11/1/01-5/30/13; Era 2 (E2) 6/1/13-8/12/20 based on changes in practice that occurred pursuant to donor age and pancreas cold ischemia time (CIT).

RESULTS

255 consecutive SPKTs were analyzed (E1, n = 165; E2, n = 90). E1 patients received organs from older donors (mean E1 27.3 vs. E2 23.1 years) with longer pancreas cold CITs) (mean E1 16.1 vs. E2 13.3 h, both p < .05). E1 patients had a higher early relaparotomy rate (E1 43.0% vs. E2 14.4%) and were more likely to require allograft pancreatectomy (E1 9.1% vs. E2 2.2%, both p < .05). E2 patients underwent systemic venous drainage more frequently (E1 8% vs. E2 29%) but pancreas venous drainage did not influence either relaparotomy or allograft pancreatectomy rates. The most common indications for early relaparotomy in E1 were allograft thrombosis (11.5%) and peri-pancreatic phlegmon/abscess (8.5%) whereas in E2 were thrombosis, pancreatitis/infection, and bowel obstruction (each 3%).

CONCLUSION

Maximizing donor quality (younger donors) and minimizing pancreas CIT are paramount for reducing early surgical complications following SPKT.

Side-to-Side Duodenojejunal Anastomosis Volvulus After Pancreas Transplant: A Case Report

Pancreas transplant is one of the known most effective treatments for type 1 diabetes mellitus and is associated with improved survival and quality of life for patients. Most centers use a direct side-to-side anastomosis between the donor's duodenum and jejunum, and we describe a rare complication that affected 2 patients. The 2 patients each received a simultaneous kidney-pancreas transplant and presented with side-to-side duodenojejunal anastomosis volvulus. We describe the clinical and radiological presentations and then propose an effective management method. Side-to-side duodenojejunal anastomosis volvulus after pancreas transplant is an exceptional complication, and there are special radiological and surgical manage-ment techniques to allow efficient treatment.

Diabetes in Kidney Transplantation

Diabetes mellitus (DM) is one of the most common complications after kidney transplantation and is associated with unfavorable outcomes including death. DM can be present before transplant but post-transplant DM (PTDM) refers to diabetes that is diagnosed after solid organ transplantation. Despite its high prevalence, optimal treatment to prevent complications of PTDM is unknown. Medical therapy of pre-existent DM or PTDM after transplant is challenging because of frequent interactions between antidiabetic and immunosuppressive agents. There is also frequent need for medication dose adjustments due to residual kidney disease and a higher risk of medication side effects in patients treated with immunosuppressive agents. Sodium-glucose cotransporter 2 inhibitors have demonstrated a favorable cardio-renal profile in patients with DM without a transplant and hence hold great promise in this patient population although there is concern about the higher risk of urinary tract infections. The significant gaps in our understanding of the pathophysiology, diagnosis, and management of DM after kidney transplantation need to be urgently addressed.

Frailty in Pancreas Transplantation

There are a variety of definitions and criteria used in clinical practice to define frailty. In the absence of a gold-standard definition, frailty has been operationally defined as meeting 3 out of 5 phenotypic criteria indicating compromised function: low grip strength, low energy, slowed walking speed, low physical activity, and unintentional weight loss. Frailty is a common problem in solid organ transplant candidates who are in the process of being listed for a transplant, as well as after transplantation. Patients with diabetes or chronic kidney disease (CKD) are known to be at increased risk of being frail. As pancreas transplantation is exclusively performed among patients with diabetes and the majority of them also have CKD, pancreas transplant candidates and recipients are at high risk of being frail. Sarcopenia, fatigue, low walking speed, low physical activity, and unintentional weight loss, which are some of the phenotypes of frailty, are very prevalent in this population. In various solid organs, frail patients are less likely to be listed or transplanted and have high waitlist mortality. Even after a transplant, they have increased risk of prolonged hospitalization, readmission, and delayed graft function. Given the negative impact of frailty on solid organ transplants, we believe that frailty would have a similar or even worse impact on pancreas transplantation. Due to the paucity of data specifically among pancreas transplant recipients, here we include frailty data from patients with CKD, diabetes, and various solid organ transplant recipients.

Single center results of simultaneous pancreas-kidney transplantation in patients with type 2 diabetes

Studies have found similar outcomes of Simultaneous Pancreas-Kidney transplantation (SPKT) in patients with Type 2 (T2D) and Type 1 diabetes (T1D). However, there are scarce data evaluating the association of recipient factors such as age, BMI, or pretransplant insulin requirements with outcomes, thus the criteria for the optimal recipient selection remains unclear. In this study, 284 T1D and 39 T2D patients, who underwent SPKT between 2006 and 2017 with 1 year of follow-up at minimum, were assessed for potential relationship of pretransplant BMI and insulin requirements with posttransplant diabetes and pancreatic graft failure. Kaplan-Meier analysis showed similar rates of freedom from posttransplant diabetes (94.7% T2D vs. 92.3% T1D at 1 yr, and 88.1% T2D vs. 81.1% T1D at 5 yrs) and graft survival (89.7% T2D vs. 90.4% T1D at 1 yr, and 89.7% T2D vs. 81.2% T1D at 5 yrs). There was no significant association between BMI or pretransplant insulin requirements with posttransplant diabetes occurrence in either T1D (p = .10, .43, respectively) or T2D (p = .12, .63) patients in the cohort; or with graft failure (T1D: p = .40, .09; T2D: p = .71, .28). These observations suggest a less restricted approach to selective use of SPKT in patients with T2D.

Successful pancreas allotransplantations after hypothermic machine perfusion in a novel diabetic porcine model: a controlled study

The standard technique for pancreas preservation for transplantation is static cold storage (SCS). In this experimental study, we compare SCS to hypothermic machine perfusion (HMP) of the pancreas to assess if the latter could safely prolong the ischaemia period prior to transplantation. We worked in two phases, first with organ preservation for 24 h and second, preservation for either 2 or 6 h before allotransplantation. In phase 1, exocrine injury markers were found to be nonsignificantly lower, in the HMP group (n = 3) vs. SCS (n = 3) after 24 h of preservation; amylase (P = 0.2), lipase (P = 0.3) and lactate dehydrogenase (P = 0.1). In phase 2, 14 recipient diabetic pigs (after total pancreatectomy) received allotransplantations with n = 4 and n = 4 pancreases after HMP for 2 and 6 h vs. n = 3 and n = 3 pancreases after SCS for 2 and 6 h, respectively. There were no differences in recipient survival (P = 0.7), and mean survival was 14 days (0-53 days). All recipients had allograft function defined as detectable C-peptide and independent normoglycemia. We have not highlighted vascular thrombosis in all allotransplantations. This study reports the first successful pancreas allotransplantation after HMP preservation for up to 6 h with no evidence of graft thrombosis.

A Strategy to Simultaneously Cure Type 1 Diabetes and Diabetic Nephropathy by Transplant of Composite Islet-Kidney Grafts

In recent years islet cell transplant has proven itself to be a viable clinical option for a select group of diabetic patients. Graft loss after transplant however continues to hinder the long-term success of the procedure. Transplanting the islets as a pre-vascularized composite islet-kidney graft has emerged as a relevant solution. Much groundbreaking research has been done utilizing this model in conjunction with strategies aimed towards islet cell survival and prolongation of function in the host. Transplanting the islet cells as a prevascularized graft under the capsule of the donor kidney as a composite islet-kidney graft has been shown to provide long term durable blood glucose control in large animal studies by limiting graft apoptosis as well as providing a physical barrier against the host immune response. While promising, this technique is limited by long term immunosuppression requirements of the host with its well-known adverse sequelae. Research into tolerance inducing strategies of the host to the allogeneic and xenogeneic islet-kidney graft has shown much promise in the avoidance of long-term immunosuppression. In addition, utilizing xenogeneic tissue grafts could provide a near-limitless supply of organs. The islet-kidney model could provide a durable and long-term cure for diabetes. Here we summarize the most recent data, as well as groundbreaking strategies to avoid long term immunosuppression and promote graft acceptance.

Pancreas transplant versus islet transplant versus insulin pump therapy: in which patients and when?

PURPOSE OF REVIEW

The aim of the present review is to gather recent reports on the use of pancreas and islet transplantation and conventional insulin therapy for treating patients experiencing diabetes and its related complications. The present review directs attention to the current status, challenges and perspectives of these therapies and sheds light on potential future cellular therapies.

RECENT FINDINGS

The risks and benefits of diabetes treatment modalities continue to evolve, altering the risk versus benefit calculation for patients. As continuous subcutaneous insulin infusion and monitoring technologies demonstrate increasing effectiveness in achieving better diabetes control and reducing hypoglycemia frequency, so are pancreas and islet transplantation improving and becoming more effective and safer. Both beta-cell replacement therapies, however, are limited by a dependence on immunosuppression and a shortage of cadaver donors, restricting more widespread and safer deployment. Based on the effectiveness of clinical beta-cell replacement for lengthening lifespan and improving quality of life, scientists are aggressively investigating alternative cell sources, transplant platforms, and means of preventing immunological damage of transplanted cells to overcome these principle limitations.

SUMMARY

Essential goals of diabetes therapy are euglycemia, avoidance of hypoglycemia, and prevention or stabilization of end-organ damage. With these goals in mind, all therapeutic options should be considered.

Pancreas preservation: clinical practice and future developments

PURPOSE OF REVIEW

To summarize recently published studies of preservation strategies including machine perfusion in pancreas transplantation.

RECENT FINDINGS

The shortage of conventional donors is leading units to use extended criteria donors (ECDs) and donors after cardiac death (DCD). Static cold storage (SCS) is still the standard method of preservation for pancreases and University of Wisconsin remains the gold standard preservation solution. In experimental studies, oxygen delivered during preservation reduced tissue injury and improved islet cell yield and function. Hypothermic machine perfusion of discarded human pancreases has been shown to improve adenosine triphosphate levels without adversely effect histology and oedema compared with SCS. Normothermic machine perfusion of discarded human organs has so far been challenging and led to increasing injury, rather than preservation. There are currently no clinical studies in pancreas transplant with the exception of a small number of pancreases being transplanted following normothermic regional perfusion.

SUMMARY

The storm of new organ preservation methods is now being more widely studied in the pancreas, with some promising results. These new strategies have the potential to allow expansion of the donor pool and greater utilization of ECD and DCD organs.

Back-table surgery pancreas allograft for transplantation: Implications in complications

To describe the main aspects of back-table surgery in pancreatic graft and the problems arising from poor technique. Back-table surgery for pancreatic graft is a complex, meticulous and laborious technique on which the success of implant surgery and perioperative results depends. The technique can be described in the following steps: Preparation of the sterile table, ex-situ inspection of the pancreas-spleen block, management of the duodenum, identification of the bile duct, preparation of the portal vein, preparation of the own graft arteries and anastomosis to the arterial graft, spleen management and graft preservation prior to implantation in the recipient. A careful inspection of the pancreas-spleen block should be performed. It is important to identify the stump of the main bile duct, the portal vein cuff, and the arrangement of the superior mesenteric artery and splenic artery. The redundant duodenum must be removed. The availability of a good venous cuff facilitates the portal vein anastomosis and the positioning of the graft, two key points to prevent thrombosis. The section line of the arteries must be clean, without atherosclerosis, to prevent arterial thrombosis. The superior and splenic mesenteric arteries are generally separated by dense fibrolymphatic tissue. The artery can be reconstructed by interposing a "Y" graft from the donor iliac artery; or with an end-to-end anastomosis between the splenic artery and the superior mesenteric artery. An exquisite technique of bench work helps to prevent the most feared complications of pancreas transplantation: Thrombosis and graft pancreatitis.

Donor risk factors in pancreas transplantation

The aim of the work was to analyze and expose the donor and recipient risk factors in pancreas transplantation. In the following paper, we exposed the 2018 Spanish Consensus Document on Donor and Recipient Selection Criteria for Pancreas Transplantation. An assessment of the previous Selection Criteria for Donors and Recipients of Pancreas Transplantation, published in 2005 by the Spanish Pancreas Transplant Group (GETP) and the National Transplant Organization (ONT) was performed. A literature review was performed using Cochrane Library, PubMed and Google Scholar databases. Some of the following terms were used for the literature search: “Diabetes Mellitus,” “Pancreas Transplantation,” “Insulin-Secreting Cells,” “Pancreas Allograft Thrombosis,” “Allograft Pancreatitis,” “Donors’ Risk Factors,” “Recipients’ Risk Factors,” “Pancreas Allograft Rejection” and “Pancreas Allograft Survival.” After an extended search, different inclusion criteria were established. Articles and documents with abstracts of full text and in English or Spanish language were selected. Subsequently, different scientific meetings took place during 2015 and 2016 by the GETP. Finally, the updated criteria were published by the GETP and ONT in 2018. Several risk factors have been described in pancreas transplantation that can be divided into donor risk factors: Advanced age (> 50 years); high body mass index (BMI) (> 30 kg/m²); cause of death (e.g., stroke); previous hyperglycemia; hyperamylasemia; cold ischemia time (greater than 8 or 12 h, depending on the type of donation); the use of vasopressors in the intensive care unit or cardiac arrest; and the macroscopic aspect of the pancreas allograft. The following are recipient risk factors: Advanced age (> 50 years); active smoking; high BMI (> 30 kg/m²); and peripheral artery disease or sensorimotor polyneuropathy. Based on the aforementioned parameters, different selection criteria have been established for the recipients depending on the type of pancreas transplantation. Knowledge of the risk factors for pancreas transplantation allows the establishment of reliable selection criteria for choosing donors and recipients.

Single center results of simultaneous pancreas-kidney transplantation in patients with type 2 diabetes

Studies have found similar outcomes of Simultaneous Pancreas-Kidney transplantation (SPKT) in patients with Type 2 (T2D) and Type 1 diabetes (T1D). However, there are scarce data evaluating the association of recipient factors such as age, BMI, or pretransplant insulin requirements with outcomes, thus the criteria for the optimal recipient selection remains unclear. In this study, 284 T1D and 39 T2D patients, who underwent SPKT between 2006 and 2017 with 1 year of follow-up at minimum, were assessed for potential relationship of pretransplant BMI and insulin requirements with posttransplant diabetes and pancreatic graft failure. Kaplan-Meier analysis showed similar rates of freedom from posttransplant diabetes (94.7% T2D vs. 92.3% T1D at 1 yr, and 88.1% T2D vs. 81.1% T1D at 5 yrs) and graft survival (89.7% T2D vs. 90.4% T1D at 1 yr, and 89.7% T2D vs. 81.2% T1D at 5 yrs). There was no significant association between BMI or pretransplant insulin requirements with posttransplant diabetes occurrence in either T1D (p = .10, .43, respectively) or T2D (p = .12, .63) patients in the cohort; or with graft failure (T1D: p = .40, .09; T2D: p = .71, .28). These observations suggest a less restricted approach to selective use of SPKT in patients with T2D.

How Should Pancreas Transplant Rejection Be Treated?

BACKGROUND

Limited published data exist to guide the treatment of pancreas transplant rejection.

METHODS

We reviewed the treatment and outcomes of 158 first episodes of biopsy-proven pancreas rejection between 1 January 1997 and 31 December 2016. Within each Banff grade of rejection, we compared response rates and long-term outcomes with steroids alone versus steroids plus antithymocyte globulin (ATG).

RESULTS

Of 158 pancreas recipients with rejection, 65 were treated with steroids alone. Eighty-three percent of patients with grade I, 60% with grade II, and 33.33% with grade III rejection responded to treatment with steroids alone. Ninety-three patients were treated with steroids plus ATG. The response rates were 69% in grade I, 76% in grade II, and 73% in grade III. Response rates and graft survival were not different with grade I rejection treated with steroids alone versus steroids plus ATG. However, response rates and graft survival were significantly better with grade III rejection treated with the addition of ATG, and graft survival rates were significantly better with grade II rejection treated with the addition of ATG.

CONCLUSIONS

Grade I pancreas rejection can usually be successfully treated with steroids alone, whereas grade II and III rejection should usually be treated with steroids plus ATG, as the addition of ATG improves both response rates and graft survival.

Perioperative considerations for kidney and pancreas-kidney transplantation

Kidney transplantation is the treatment of choice in patients with end-stage renal disease, as it improves survival and quality of life. Living donor kidney transplant prior to pancreas transplantation, or simultaneous pancreas and kidney transplantation are discussed. Patients usually present comorbidities and extensive preoperative workups are recommended, especially cardiac assessment, though type and frequency of surveillance is not established. Nephroprotective strategies include adequate fluid status and goal-directed therapy. The conventional use of diuretics has not demonstrated a real nephroprotective effect at follow-up. Thromboprophylaxis regimes, especially for the pancreatic graft outcome, are of importance. Notably, transplantation in the obese population has increased in recent decades. Strict preoperative evaluation and pulmonary considerations must be kept in mind. Finally, robotic kidney transplant is a recent approach that presents anesthetic challenges, mainly related to steep Trendelenburg position and fluid restriction.

Ex situ Perfusion of Pancreas for Whole-Organ Transplantation: Is it Safe and Feasible? A Systematic Review

INTRODUCTION

Pancreas transplantation is currently one of the best treatments proposed in highly selected patients with unstable and brittle type 1 diabetes. The objective of pancreas transplantation is to restore normoglycemia and avoid the occurrence of complications associated with diabetes. Graft pancreatitis and thrombosis, arising from ischemia reperfusion injuries, are major causes of graft loss in the postoperative period. Ex situ perfusion, in hypothermic or normothermic settings, allowed to improve ischemic reperfusion injury in other organ transplantations (kidney, liver, or lung). The development of pancreatic graft perfusion techniques would limit these ischemic reperfusion injuries.

OBJECTIVE

Evaluation of the safety and feasibility of ex situ perfusion of pancreas for whole-organ transplantation.

METHODS

English literature about pancreas perfusion was analyzed using electronic database Medline via PubMed (1950-2018). Exclusion criteria were studies that did not specify the technical aspects of machine perfusion and studies focused only on pancreas perfusion for islet isolation.

RESULTS

Hypothermic machine perfusion for pancreas preservation has been evaluated in nine studies and normothermic machine perfusion in ten studies. We evaluated machine perfusion model, types of experimental model, anatomy, perfusion parameters, flushing and perfusion solution, length of perfusion, and comparison between static cold storage and perfusion.

CONCLUSIONS

This review compared ex vivo machine perfusion of experimental pancreas for whole-organ transplantation. Pancreas perfusion is feasible and could be a helpful tool to evaluate pancreas prior to transplantation. Pancreas perfusion (in hypothermic or normothermic settings) could reduce ischemic reperfusion injuries, and maybe could avoid pancreas thrombosis and reduce morbidity of pancreas transplantation.

Progression of diabetic nephropathy after successful pancreas transplantation alone: a case report

Pancreas transplantation is the only method that can nearly cure insulin-dependent diabetes mellitus. However, the effect of pancreas transplantation on patients with diabetic nephropathy has recently been considered controversial. In this report, we present a case of abrupt aggravation of proteinuria after successful pancreas transplantation alone without evidence of calcineurin inhibitor (CNI) toxicity. A 22-year-old female patient with type I diabetes mellitus underwent pancreas transplantation alone. The patient already had retinopathy and mild proteinuria, which in this case, may mean diabetic nephropathy. Her glucose levels were managed within the normal range after successful pancreas transplantation. However, the amount of proteinuria fluctuated. Kidney needle biopsy was performed owing to severe elevation of proteinuria, 2 years after the transplantation. Electron microscopy revealed diabetic glomerulosclerosis without evidence of CNI toxicity. This case indicates that diabetic nephropathy can be aggravated after pancreas transplantation, despite well-managed glucose levels and absence of CNI toxicity.

Challenges of pancreas transplantation in developing countries, exploring the Turkey example

Pancreas transplantation significantly improves the quality of life for people with type 1 diabetes, primarily by eliminating the need for insulin and frequent blood glucose measurements. Despite the growing numbers of solid organ transplantations worldwide, number of pancreas transplantations in the developing countries` remain significantly low. This difference of pancreas transplantation practices was striking among the participating countries at the 1st International Transplant Network Meeting which was held in Turkey on 2018. In this meeting more than 40 countries were represented. Most of these counties were developing countries located in Africa, Middle East or Asia. The aim of this article is to identify the challenges and limiting factors for pancreas transplantations in these developing countries, by exploring the Turkish example. The challenges faced by the developing countries are broadly classified in four categories; wait-listing, donor pool, team work and follow up. Under these categorical titles, issues are further discussed in detail, giving examples from Turkish practice of pancreas transplantation. Additionally, several solutions to these challenges have been proposed- some of which have already been undertaken by the Turkish Ministry of Health. With the insight and methods presented in this article, pancreas transplantation should be made possible for the potential recipients in the developing countries.

Delayed Bleeding of the Transplant Duodenum After Simultaneous Kidney-pancreas Transplantation: Case Series

BACKGROUND

In simultaneous pancreas-kidney (SPK) transplant recipients, the majority of complications described in the literature, are early postoperative complications. However, there is growing attention for late complications associated with SPK transplantation.

METHODS

In this case series, we present 3 cases, 2 enterically and 1 bladder-derived SPK transplant patients, with anastomotic hemorrhage of the donor duodenum as a very late complication, >10 years after transplantation (11, 22, and 18 y later, respectively).

RESULTS

In our center, 122 SPK transplantations have been performed between January 1992 and June 2018. The 3 cases reported here are the only patients in our cohort presenting with delayed anastomotic hemorrhage of the donor duodenum (2.5%). In the first 2 patients, reintervention with reconstruction of the anastomosis was performed. A congestive and friable mucosa was seen, and the resection specimen showed enlarged and congestive submucosal veins in both patients. There was no recurrence of bleeding after reintervention. In the third patient, enteric derivation was not possible because of the extremely fragile intestinal tissue perioperatively, and a conservative approach was taken. As possible precipitating factors are concerned, all 3 of our patients were taking low-dose aspirin and/or clopidogrel as secondary cardiovascular prevention.

CONCLUSIONS

Bleeding of the transplanted donor duodenum can present as a late complication, several years after SPK transplantation. The development of enlarged, congestive submucosal veins could play a role in these late bleedings, and antiplatelet therapy could be a precipitating factor. Further research is necessary to investigate the pathophysiology, the prevalence, optimal treatment, and the consequent influence on mortality, morbidity, and graft loss after SPK transplantation.

Pancreatic Islet Transplantation in Humans: Recent Progress and Future Directions

Pancreatic islet transplantation has become an established approach to β-cell replacement therapy for the treatment of insulin-deficient diabetes. Recent progress in techniques for islet isolation, islet culture, and peritransplant management of the islet transplant recipient has resulted in substantial improvements in metabolic and safety outcomes for patients. For patients requiring total or subtotal pancreatectomy for benign disease of the pancreas, isolation of islets from the diseased pancreas with intrahepatic transplantation of autologous islets can prevent or ameliorate postsurgical diabetes, and for patients previously experiencing painful recurrent acute or chronic pancreatitis, quality of life is substantially improved. For patients with type 1 diabetes or insulin-deficient forms of pancreatogenic (type 3c) diabetes, isolation of islets from a deceased donor pancreas with intrahepatic transplantation of allogeneic islets can ameliorate problematic hypoglycemia, stabilize glycemic lability, and maintain on-target glycemic control, consequently with improved quality of life, and often without the requirement for insulin therapy. Because the metabolic benefits are dependent on the numbers of islets transplanted that survive engraftment, recipients of autoislets are limited to receive the number of islets isolated from their own pancreas, whereas recipients of alloislets may receive islets isolated from more than one donor pancreas. The development of alternative sources of islet cells for transplantation, whether from autologous, allogeneic, or xenogeneic tissues, is an active area of investigation that promises to expand access and indications for islet transplantation in the future treatment of diabetes.

Feasibility of Laparoscopic Combined Para-Orthotopic Pancreas and Orthotopic Kidney Transplantation: Initial Research with a Pig Model

BACKGROUND The aim of this study was to investigate the feasibility of laparoscopic combined para-orthotopic pancreas and orthotopic kidney transplantation in a pig model. MATERIAL AND METHODS Twelve white female pigs, (4-5 months old, weight range 40-45 kg) were used as donors and recipients, and 6 laparoscopic-combined pancreas and kidney transplantations were performed. After bilateral nephrectomy, the pancreatic artery and vein were anastomosed to the right renal artery and vein, respectively, and the pancreatic fluid was diverted to the duodenum or jejunum. The renal artery and vein were anastomosed to the left renal artery and vein, respectively. The ureter (or kidney pelvis) was anastomosed to the left native ureter (or kidney pelvis). The data of the operations were recorded, and grafts were inspected at autopsy. RESULTS Four of the 6 recipient pigs underwent the entire procedure. The duodenum-to-duodenum anastomosis was unfinished in 1 case, and both the duodenum-to-duodenum and renal pelvis-to-pelvis anastomoses were left unperformed in another case. The mean recipient operative time was 429±43 minutes. The mean venous and arterial anastomotic times were 69±15 minutes and 37±18 minutes, respectively, for pancreas transplantation and 56±09 minutes and 42±06 minutes, respectively, for kidney transplantation. The time for renal pelvis-to-pelvis anastomosis was 56±13 minutes and for duodenum-to-duodenum anastomosis was 90±13 minutes. The mean blood loss for recipient pigs was 98±35 mL. An immediate viable blood supply was seen in the 4 pancreatic grafts and in the 5 kidney grafts during the operation by the appearance of a bright red color after revascularization. Five pancreatic grafts had autopsy-proven reliable artery anastomoses and 4 reliable vein anastomoses. All 6 kidney grafts had autopsy-proven reliable artery anastomoses; however, 1 had a vein anastomotic stricture. CONCLUSIONS Our study showed that laparoscopic-combined para-orthotopic pancreas and orthotopic kidney transplantation in pigs is surgically possible.

Hypothermic pulsatile perfusion of human pancreas: Preliminary technical feasibility study based on histology

BACKGROUND

There are currently two approaches to hypothermic preservation for most solid organs: static or dynamic. Cold storage is the main method used for static storage (SS), while hypothermic pulsatile perfusion (HPP) and other machine perfusion-based methods, such as normothermic machine perfusion and oxygen persufflation, are the methods used for dynamic preservation. HPP is currently approved for kidney transplantation.

METHODS

We evaluated, for the first time, the feasibility of HPP on 11 human pancreases contraindicated for clinical transplantation because of advanced age and/or history of severe alcoholism and/or abnormal laboratory tests. Two pancreases were used as SS controls, pancreas splitting was performed on 2 other pancreases for SS and HPP and 7 pancreases were tested for HPP. HPP preservation lasted 24 h at 25 mmHg. Resistance index was continuously monitored and pancreas and duodenum histology was evaluated every 6 h.

RESULTS

The main finding was the complete absence of edema of the pancreas and duodenum at all time-points during HPP. Insulin, glucagon and somatostatin staining was normal. Resistance index decreased during the first 12 h and remained stable thereafter.

CONCLUSION

24 h hypothermic pulsatile perfusion of marginal human pancreas-duodenum organs was feasible with no deleterious parenchymal effect. These observations encourage us to further develop this technique and evaluate the safety of HPP after clinical transplantation.

β Cell Replacement Therapy: The Next 10 Years

β cell replacement with either pancreas or islet transplantation has progressed immensely over the last decades with current 1- and 5-year insulin independence rates of approximately 85% and 50%, respectively. Recent advances are largely attributed to improvements in immunosuppressive regimen, donor selection, and surgical technique. However, both strategies are compromised by a scarce donor source. Xenotransplantation offers a potential solution by providing a theoretically unlimited supply of islets, but clinical application has been limited by concerns for a potent immune response against xenogeneic tissue. β cell clusters derived from embryonic or induced pluripotent stem cells represent another promising unlimited source of insulin producing cells, but clinical application is pending further advances in the function of the β cell like clusters. Exciting developments and rapid progress in all areas of β cell replacement prompted a lively debate by members of the young investigator committee of the International Pancreas and Islet Transplant Association at the 15th International Pancreas and Islet Transplant Association Congress in Melbourne and at the 26th international congress of The Transplant Society in Hong Kong. This international group of young investigators debated which modality of β cell replacement would predominate the landscape in 10 years, and their arguments are summarized here.

Extracellular matrix scaffold and hydrogel derived from decellularized and delipidized human pancreas

Extracellular matrix (ECM) plays an important developmental role by regulating cell behaviour through structural and biochemical stimulation. Tissue-specific ECM, attained through decellularization, has been proposed in several strategies for tissue and organ replacement. Decellularization of animal pancreata has been reported, but the same methods applied to human pancreas are less effective due to higher lipid content. Moreover, ECM-derived hydrogels can be obtained from many decellularized tissues, but methods have not been reported to obtain human pancreas-derived hydrogel. Using novel decellularization methods with human pancreas we produced an acellular, 3D biological scaffold (hP-ECM) and hydrogel (hP-HG) amenable to tissue culture, transplantation and proteomic applications. The inclusion of a homogenization step in the decellularization protocol significantly improved lipid removal and gelation capability of the resulting ECM, which was capable of gelation at 37 °C in vitro and in vivo, and is cytocompatible with a variety of cell types and islet-like tissues in vitro. Overall, this study demonstrates the characterisation of a novel protocol for the decellularization and delipidization of human pancreatic tissue for the production of acellular ECM and ECM hydrogel suitable for cell culture and transplantation applications. We also report a list of 120 proteins present within the human pancreatic matrisome.

Pancreas transplant rejection episodes are not revealed by biopsies of the donor duodenum in a prospective study with paired biopsies

The surgical technique with duodeno-duodenal enteroanastomosis of pancreas transplants allows for representative endoscopic ultrasound-guided needle biopsies of the donor duodenum and the pancreas graft. We assessed whether histological findings in transplanted donor duodenal biopsies can indicate rejection in the transplanted pancreas. Since September 2012, a duodeno-duodenal enteroanastomosis has been the default technique for pancreas transplantations at our center. In 67 recipients we prospectively examined 113 endoscopic ultrasound-guided procedures with representative biopsies from the duodenum grafts and the pancreas grafts (97 per protocol and 16 on indication). All graft biopsies were evaluated according to established rejection criteria. A total of 22 biopsy-proven pancreas rejections were detected, with 2 matching duodenal biopsies showing rejection. This gives a sensitivity of 9% for detection of a pancreas rejection by duodenal biopsies. The other matching duodenal biopsies were either normal (n = 13) or indeterminate (n = 7). Rejection of the donor duodenum was found in only 6/113 biopsies, with 2 concurrent pancreas rejections. In conclusion, the donor duodenum is not a useful reporter organ for rejection in the pancreas graft.

Pancreas transplantation in unconventional recipients

PURPOSE OF REVIEW

Advances in surgical technique and immunosuppression have significantly improved outcomes after pancreas transplantation, and as a result pancreas transplants increasingly are being performed for indications other than type 1 diabetes mellitus. This review summarizes the current literature on pancreas transplantation in unconventional recipient populations.

RECENT FINDINGS

An increasing body of work suggests that pancreas transplantation can be performed with good outcomes in patients with type 2 diabetes mellitus and those 50 years of age and older. Obesity appears detrimental to patient and pancreas graft survival, and bariatric surgery prior to transplantation may be of increasing interest and relevance. There are limited data yielding mixed outcomes on pancreas transplantation in patients with HIV or hepatitis C virus. However, rapidly improving antiviral therapies are prolonging survival in patients with HIV and chronic hepatitis C virus infections and may increase the number of candidates available for pancreas transplantation in these populations in the future.

SUMMARY

Despite limited literature in these patient populations, pancreas transplantation may be a viable treatment option for endocrine pancreas failure in appropriately selected patients regardless of disease cause or age.

Significance of steatosis in pancreatic transplantation

The on-going success of whole organ pancreatic transplantation is dependent on overcoming the imbalance between demand and supply of optimal organs as well as tackling the vast comorbidity associated with the procedure. Pancreas steatosis is a common contributing factor to the problem and with obesity pandemics affecting the global population; the size and type of organs received from donors will only make steatosis more of an issue. The aim of this review is to highlight what is known about steatosis in the context of pancreas transplantation identifying potential methods to help its evaluation. Narrative review of literature from inception to June 2017, using OVID interface searching EMBASE and MEDLINE databases as well recent transplant conference data. All studies related to pancreas steatosis examined for clinical relevance with no exclusion criteria. Key ideas extracted and referenced. Pancreatic steatosis is not innocuous and is precariously regarded by transplant surgeons, however its associations with obesity, metabolic syndrome and long list of associated complications clearly show it needs more careful consideration. Radiologic and surgical advances now allow assessment of the fat content of organs, which could be used to quantify organs allowing better optimisation, but there is still much work to be done to refine the optimal method to achieve this.

Pancreas Transplantation After Liver Transplantation: A Case Report

Our aim was to describe the clinical indications, surgical technique, and clinical outcomes of a pancreas transplantation, performed 4 years after liver transplantation, as treatment for new-onset, uncontrolled diabetes mellitus in a 53-year-old man. Liver transplantation was performed for end-stage liver disease secondary to hepatitis B virus infection and hepatocellular carcinoma. The patient had no history of diabetes prior to the liver transplantation. The decision to proceed with a pancreas transplantation was made when the patient's blood sugar levels could not be normalized despite insulin doses >100 IU/d. A modified cadaveric transplantation technique was used, with the recipient's inferior vena cava dissected for anastomosis with the portal vein of the graft, using a diamond-shaped patch procedure. Moreover, the right common iliac artery was anastomosed with a Y-graft in the pancreas graft, and the duodenum remnant of the graft was anastomosed to the recipient's duodenum using a side-to-side procedure. The 6-month postoperative follow-up included repeated endoscopic biopsy of the graft duodenum, with no evidence of thrombosis or rejection of the graft, with glucose level within normal limits without requirement for diabetic drugs. To our knowledge, this is the first reported case of pancreas transplantation after liver transplantation.

Research progress of mesenchymal stem cells combined with islet transplantation in treatment of type I diabetes mellitus

The most significant feature of type I diabetes is β-cell loss, which results in a series of complications. While β-cell loss occurs, β-cells are ultimately damaged by macrophages and T cells in the presence of inflammatory mediators. Because of this characteristic, five kinds of antibodies are commonly used in clinical practice to diagnose and evaluate β-cell loss, including islet cell antibody, insulin antibody, GAD65, IA-2 and IA-2b. In addition to the HLA gene related factors, environmental factors, such as infection, diet and physiological and psychological factors, are suspected to be causes of this disease. At present, there are many treatments for type I diabetes, and the clinical goal is to control blood glucose, prevent further damage of βcells and control patients' own immune response. In 1992, the discovery of insulin, which converts the fatal diabetes into a chronic disease, to some extent, delayed the progression of microvascular complications; however, it is not able to delay the progression of the disease. β-cell transplantation is currently the only minimally invasive means for reasonable control of blood glucose control disease related complications. Although whole pancreas transplantation can achieve a promising effect to some extent, it is accompanied by high incidence and mortality, as well as lifelong mandatory immune suppression. Bone marrow mesenchymal stem cells transplantation, lipopolysaccharideon (LPS) bone marrow mesenchymal stem cell pretreatment and islet cell exendin-4 liquid preservation reduce warm ischemia time damage and provide new avenues for islet cell transplantation.