Pancreas transplantation: 50 years of experience

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.

A New Mouse Model of Whole Pancreas Transplant With Graft Blood Through the Portal Vein

OBJECTIVES

Pancreas transplant is currently the most effective method for maintaining physiological blood sugar levels and reversing small blood vessel injuries. Our team developed a model of whole pancreas transplant based on microsurgical techniques following the investigation of more than 300 mice.

MATERIALS AND METHODS

A mouse pancreatic transplant model is required to investigate the pathophysiological process of pancreas transplant and pancreatic preservation technologies. Recently, the segment-neck pancreas transplant has been the most utilized mouse pancreatic transplant model. The innovative mouse pancreatic transplant modelthat we developed in this study uses the whole pancreas and returns heart blood flow into the liver via the portal vein.

RESULTS

With our mouse pancreatic transplant model, the survivalrate of mice aftertransplant was >80%, and the success rate of pancreatic transplant was >90%.

CONCLUSIONS

The segment-neck and the whole pancreas model can guarantee that the transplanted pancreas functions effectively, and both have excellent postoperative outcomes, survivalrates and pancreatic active rates.

Importance of multiple endocrine cell types in islet organoids for type 1 diabetes treatment

Almost 50 years ago, scientists developed the bi-hormonal abnormality hypothesis, stating that diabetes is not caused merely by the impaired insulin signaling. Instead, the presence of inappropriate level of glucagon is a prerequisite for the development of type 1 diabetes (T1D). It is widely understood that the hormones insulin and glucagon, secreted by healthy β and α cells respectively, operate in a negative feedback loop to maintain the body's blood sugar levels. Despite this fact, traditional T1D treatments rely solely on exogenous insulin injections. Furthermore, research on cell-based therapies and stem-cell derived tissues tends to focus on the replacement of β cells alone. In vivo, the pancreas is made up of 4 major endocrine cell types, that is, insulin-producing β cells, glucagon-producing α cells, somatostatin-producing δ cells, and pancreatic polypeptide-producing γ cells. These distinct cell types are involved synergistically in regulating islet functions. Therefore, it is necessary to produce a pancreatic islet organoid in vitro consisting of all these cell types that adequately replaces the function of the native islets. In this review, we describe the unique function of each pancreatic endocrine cell type and their interactions contributing to the maintenance of normoglycemia. Furthermore, we detail current sources of whole islets and techniques for their long-term expansion and culture. In addition, we highlight a vast potential of the pancreatic islet organoids for transplantation and diabetes research along with updated new approaches for successful transplantation using stem cell-derived islet organoids.

A centennial review of discoveries and advances in diabetes: Children and youth

Diabetes is an increasingly common chronic metabolic disorder in children worldwide. The discovery of insulin in 1921 resulted in unprecedented advancements that improved the lives of children and youth with diabetes. The purpose of this article is to review the history of diabetes in children and youth over the last century and its implications for future developments in the field. We identified 68 relevant events between 1921 and 2021 through literature review and survey of pediatric endocrinologists. Basic research milestones led to the discovery of insulin and other regulatory hormones, established the normal physiology of carbohydrate metabolism and pathophysiology of diabetes, and provided insight into strategies for diabetes prevention. While landmark clinical studies were initially focused on adult diabetes populations, later studies assessed etiologic factors in birth cohort studies, evaluated technology use among children with diabetes, and investigated pharmacologic management of youth type 2 diabetes. Technological innovations culminated in the introduction of continuous glucose monitoring that enabled semi-automated insulin delivery systems. Finally, professional organizations collaborated with patient groups to advocate for the needs of children with diabetes and their families. Together, these advances transformed type 1 diabetes from a terminal illness to a manageable disease with near-normal life expectancy and increased our knowledge of type 2 diabetes and other forms of diabetes in the pediatric population. However, disparities in access to insulin, diabetes technology, education, and care support remain and disproportionately impact minority youth and communities with less resources. The overarching goal of diabetes management remains promoting a high quality of life and improving glycemic management without undermining the psychological health of children and youth living with diabetes.

Breaking the limits of experimental pancreas transplantation: Working toward the clinical ideal graft

Pancreas transplantation is, at present, the only curative treatment for type-1 diabetes that maintains normoglycemia thus avoiding complications arising from poor glycemic control. Despite its great benefits, the number of pancreas transplants has decreased significantly since its inception in the late 1960s, largely due to demographic changes and the consequent suboptimal quality of donors. The selection criteria for pancreas donors mainly depend on morphological variables such as fatty infiltration, fibrosis, or edema, as well as both functional (amylase and lipase) and clinical variables of the donor. However, the final criterion in the decision-making process is the somewhat subjective assessment of a trained surgeon. That being said, the recent incorporation of graft perfusion machines into clinical practice seems to be changing the work dynamics of the donor organ retrieval team, facilitating decision-making based on objective morphological and functional criteria. Normothermic perfusion using perfusate with supplemental oxygen replicates near physiological parameters thus being a promising strategy for organ preservation. Nevertheless, optimum perfusion parameters are difficult to establish in pancreas transplantation given its complex vascular anatomy combined with an intrinsically low blood flow. The objective of this work is to analyze the results published in the recent literature relating to the considerations of ex-vivo normothermic graft perfusion machines and their usefulness in the field of pancreas transplantation.

Current Trends in Organ Preservation Solutions for Pancreas Transplantation: A Single-Center Retrospective Study

Due to the high vulnerability of the pancreas to ischemia-reperfusion injury, choices regarding preservation solution markedly affect pancreas transplant success. A retrospective single-center analysis of 380 pancreas transplants (2000–2019) was performed to correlate current preservation solutions with transplant outcomes. Early graft failure requiring transplantectomy within 30 days post-transplant occurred in 7.5% for University of Wisconsin (UW) group (n = 267), 10.8% of Celsior (CS) group (n = 83), 28.5% of Histidine-Tryptophan-Ketoglutarate (HTK) group (n = 7), and none for Institut Georges Lopez-1 (IGL-1) group (n = 23). The most common causes of technical failures in this cohort included abdominal hemorrhage (8.4%); graft pancreatitis (3.7%); fluid collections (2.6%); intestinal complications (6.6%); and vascular thrombosis (20.5%). Although IGL-1 solution provided lower surgical complication rates, no significant differences were found between studied groups. Nevertheless, HTK solution was associated with elevated pancreatitis rates. The best graft survival was achieved at 1 year using UW and IGL-1, and at 3 and 5 years using IGL-1 (p = 0.017). There were no significant differences in patient survival after a median follow-up of 118.4 months. In this setting therefore, IGL-1 solution appears promising for perfusion and organ preservation in clinical pancreas transplantation, compared to other commonly used solutions.

Results after 13 years of kidney-pancreas transplantation in type 1 diabetic patients in Comunidad Valenciana

INTRODUCTION

Simultaneous pancreas-kidney (SPK) transplant is a proven option of treatment for patients with type 1 diabetes mellitus and related end-stage renal disease, who are candidates for kidney transplantation. The results from the beginning of SPK transplant program in Comunidad Valenciana are presented.

METHODS

Descriptive, retrospective, and single-center study of the pancreas transplant performed at the Hospital Universitari i Politècnic La Fe, from September 2002 to December 2015. Clinical variables from donors and recipients, peri-operative variables, patient survival, and pancreatic graft survival were collected.

RESULTS

Eighty-one patients with type 1 diabetes mellitus (48 males and 33 females, mean age 37.4 ± 5.7 years, mean BMI 24.1 ± 3.4 kg/m², mean duration of diabetes 25.5 ± 6.5 years) received SPK transplantation. The overall patient survival at one, 3, and 5 years were 91.3%, 91.3% and 89.5%, respectively. However, patient survival in the periods 2002-2008 and 2009-2015 were 88.2% and 93.6% at one year, 88.2% and 93.7% at 3 years, and 85.3% and 93.7% at 5 years, respectively (P = 1). The overall pancreatic graft survival at one, 3, and 5 years were 75.2%, 69.1% and 63.2%, respectively. On the other hand, pancreatic graft survival in the periods 2002-2008 and 2009-2015 were 67.5% and 80.6% at one year, 64.7% and 71.8% at 3 years, and 58.8% and 65.3% at 5 years, respectively (P = .0109). Post-transplant complications were: graft rejection 8.6%, venous graft thrombosis 7.4%, graft pancreatitis 4.9%.

CONCLUSIONS

In 13 years' experience of SPK transplantation, patient and pancreatic graft survival and the rate of complications after pancreas transplantation were similar to those of other larger series. The medical-surgical team experience improves pancreatic graft survival without influencing patient survival.

Results after 13 years of kidney-pancreas transplantation in type 1 diabetic patients in Comunidad Valenciana

INTRODUCTION

Simultaneous pancreas-kidney (SPK) transplant is a proven option of treatment for patients with type 1 diabetes mellitus and related end-stage renal disease, who are candidates for kidney transplantation. The results from the beginning of SPK transplant program in Comunidad Valenciana are presented.

METHODS

Descriptive, retrospective, and single-center study of the pancreas transplant performed at the Hospital Universitari i Politècnic La Fe, from September 2002 to December 2015. Clinical variables from donors and recipients, peri-operative variables, patient survival, and pancreatic graft survival were collected.

RESULTS

Eighty-one patients with type 1 diabetes mellitus (48 males and 33 females, mean age 37.4±5.7 years, mean BMI 24.1±3.4kg/m2, mean duration of diabetes 25.5±6.5 years) received SPK transplantation. The overall patient survival at one, 3, and 5 years were 91,3, 91,3 and 89,5%, respectively. However, patient survival in the periods 2002-2008 and 2009-2015 were 88.2 and 93.6% at one year, 88.2 and 93.7% at 3 years, and 85.3 and 93.7% at 5 years, respectively (P=1). The overall pancreatic graft survival at one, 3, and 5 years were 75.2, 69.1 and 63.2%, respectively. On the other hand, pancreatic graft survival in the periods 2002-2008 and 2009-2015 were 67.5 and 80.6% at one year, 64.7 and 71.8% at 3 years, and 58.8% and 65.3% at 5 years, respectively (P=.0109). Postransplant complications were: graft rejection 8.6%, venous graft thrombosis 7.4%, graft pancreatitis 4.9%.

CONCLUSIONS

In 13-year's experience of SPK transplantation, patient and pancreatic graft survival and the rate of complications after pancreas transplantation were similar to those of other larger series. The medical-surgical team experience improves pancreatic graft survival without influencing patient survival.

Regenerative medicine of pancreatic islets

The pancreas became one of the first objects of regenerative medicine, since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted. The number of people living with diabetes mellitus is currently approaching half a billion, hence the crucial relevance of new methods to stimulate regeneration of the insulin-secreting β-cells of the islets of Langerhans. Natural restrictions on the islet regeneration are very tight; nevertheless, the islets are capable of physiological regeneration via β-cell self-replication, direct differentiation of multipotent progenitor cells and spontaneous α- to β- or δ- to β-cell conversion (trans-differentiation). The existing preclinical models of β-cell dysfunction or ablation (induced surgically, chemically or genetically) have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation. The ultimate goal, sufficient level of functional activity of β-cells or their substitutes can be achieved by two prospective broad strategies: β-cell replacement and β-cell regeneration. The “regeneration” strategy aims to maintain a preserved population of β-cells through in situ exposure to biologically active substances that improve β-cell survival, replication and insulin secretion, or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β- to β-cell conversion. The “replacement” strategy implies transplantation of β-cells (as non-disintegrated pancreatic material or isolated donor islets) or β-like cells obtained ex vivo from progenitors or mature somatic cells (for example, hepatocytes or α-cells) under the action of small-molecule inducers or by genetic modification. We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally active β-cells, the innermost hope of millions of people globally.

Machine Perfusion and the Pancreas: Will It Increase the Donor Pool?

PURPOSE OF REVIEW

Pancreas transplantation enables complete patient independence from exogenous insulin administration and increases both patient survival and quality of life. Despite this, there has been a decline in pancreas transplantation for the past 20 years, influenced by changing donor demographics with more high-risk extended criteria (ECD) and donation after cardiac death (DCD) donors. This review discusses whether the advent of machine perfusion (MP), if extended to the pancreas, can increase the pool of suitable donor organs.

RECENT FINDINGS

Hypothermic and normothermic MP, as forms of preservation deemed superior to cold storage for high-risk kidney and liver donor organs, have opened the avenue for translation of this work into the pancreas. Recent experimental models of porcine and human ex-vivo pancreatic MP are promising. Applications of MP to the pancreas however need refinement-focusing on perfusion protocols and viability assessment tools. Emerging research shows pancreatic MP can potentially offer superior preservation capacity, the ability to both resuscitate and manipulate organs, and assess functional and metabolic organ viability. The future of MP will lie in organ assessment and resuscitation after retrieval, where ultimately organs initially considered high risk and unsuitable for transplantation will be optimised and transformed, making them then available for clinical use, thus increasing the pool of suitably viable pancreata for transplantation.