A 9-year experience with 126 pancreas transplants with portal enteric drainage

Are there still roles for exocrine bladder drainage and portal venous drainage for pancreatic allografts?

PURPOSE OF REVIEW

Controversy remains regarding the best methodology of handling exocrine pancreatic fluid and pancreatic venous effluent. Bladder drainage has given way to enteric drainage. However, is there an instance in which bladder drainage is preferable? Also, hyperinsulinemia, as a result of systemic venous drainage (SVD), is claimed to be proatherosclerotic, whereas portal venous drainage (PVD) is more physiologic and less atherosclerotic.

RECENT FINDINGS

Bladder drainage remains a viable method of exocrine pancreas drainage, but evidence is sparse that measuring urinary amylase has a substantial benefit in the early detection of acute rejection in all types of pancreas transplants. Currently, there is no incontrovertible evidence that systemic hyperinsulinemia is proatherosclerotic, whereas recent metabolic studies on SVD and PVD showed that there was no benefit to PVD.

SUMMARY

Given the advent of newer immunosuppressive agents and overall lower acute rejection rates, the perceived benefit of bladder drainage as a means to measure urinary amylase as an early marker of rejection has not been substantiated. However, there may be a selective role for bladder drainage in 'high risk' pancreases. Also, without a clear-cut metabolic benefit to PVD over SVD, it remains the surgeon's choice as to which method to use.

Functional and morphological study of cultured pancreatic islets treated with cyclosporine

Cyclosporine A (CsA), a potent immunosuppressive drug, has been found to induce glucose intolerance through its toxic effect on the endocrine pancreas. It is not exactly known whether CsA has a direct effect on the endocrine pancreas or induces its effect indirectly. The present study was therefore undertaken to examine the function and morphology of isolated pancreatic islets when they are directly exposed in vitro to CsA. Pancreatic islets were isolated from adult male Lewis rats using collagenase ductal perfusion technique. The islets were separated with the discontinuous Ficoll gradient technique and further purified by hand picking of the non-islet tissue. The islets were cultured in RPMI-1640, pH 7.4 and maintained at 37 degrees C in a humid atmosphere of 5% (v/v) carbon dioxide in air. Cyclosporine was added to the culture medium to give a final concentration of 1 microg/ml (therapeutic dose), 5 microg/ml (toxic dose), or vehicle (control). Islets were harvested at 1, 4 and 10 days of culture and processed for functional or histological study. The functional study of the islets cultured with 1 microg/ml CsA showed insulin and C-peptide contents similar to those of the control islets. The islets cultured with 5 microg/ml CsA showed a marked decrease in insulin and C-peptide contents. Glucose-dependent insulin release was variable. C-peptide release was lower than that of the control following both the therapeutic and toxic doses of CsA. Phase contrast microscopy showed that the islets cultured with 1 microg/ml CsA were mostly normal looking with a well-defined regular periphery; a few islets had ill-defined or irregular peripheries. The islets cultured with 5 microg/ml CsA had ill-defined irregular peripheries at 1 day, and were dense and forming clumps at 4 and 10 days following culture. There was a decrease in the islet number following the therapeutic dose; the decrease was more following the toxic dose of CsA. The islet diameters increased after the therapeutic dose, but slightly decreased following the toxic dose of CsA. Islets showed a weakly positive immunoperoxidase reaction for insulin that was weaker following the toxic dose of CsA. It is concluded that CsA has a direct effect on B-cells that was proved by the functional and morphological changes seen in the pancreatic islets cultured in vitro.

The long-term management of pancreas transplantation

Diabetes mellitus (DM) is a major health problem worldwide, which affects 18.2 million individuals (6.3% of the population) in the United States. Currently, the prevalence of Type 1 DM in the United States is estimated to be 1,000,000 individuals, and 30,000 new cases are diagnosed each year. In addition to end-stage renal disease (ESRD), DM is associated with blindness, accelerated atherosclerosis, dyslipidemia, cardio- and cerebrovascular disease, amputation, poor quality of life, and overall lifespan reduction. It accounts for more than 160,000 deaths per year in the United States alone. In 2002, the annual national direct and indirect costs of Types 1 and 2 DM exceeded $130 billion, which included hospital and physician care, laboratory tests, pharmaceutical products, and patient workdays lost because of disability or premature death. Hyperglycemia alone or in concert with hypertension is the primary factor influencing the development of major diabetic complications. From 1990 to 2001, the number of existing ESRD cases to DM increased by more than 300%, while the rate per million populations increased from 167% to 491%. The number is expected to grow 10-fold by 2030 to 1.3 million accounting for 60% of ESRD population. To date, DM is the leading indication for transplantation and is the cause of ESRD in more than 40% of all transplant recipients each year.

[Diabetes Type I therapy through transplantation]

Diabetes is one of the most common chronic diseases in our society. While insulin treatment for diabetes type I could delay and reduce the incidence of diabetic complications, it is associated with an increased risk of severe hypoglycemia. To restore physiologic insulin metabolism, transplantation of insulin producing cells (pancreatic Beta cells) represent the sole available therapy. It could be done either through pancreas or islet of Langerhans transplantation. In this paper, we review actual knowledge regarding these two types of transplantations.

[Pancreatic Transplantation: 2. Surgical technique and post-operative complications]

Since the first pancreatic allograft in 1966, pancreatic transplantations have been performed by numerous surgical teams throughout the world. Initial results were disappointing with a high percentage of technical failures and rejection. Over-optimistic enthusiasm for islet-cell allografts also retarded the development of pancreatic transplantation. Despite this slow start, results of pancreatic transplantation from 1995 onward have been very satisfactory and equivalent to or even better than the results of other solid organ transplants. This success has been due to better graft selection, improved surgical techniques and preservation solutions, and especially to improvements in immunosuppressive protocols. More than 19,000 pancreatic transplantations have now been performed throughout the world including both combined kidney-pancreas transplantations and pancreas-only transplantations. The most satisfactory results occur in the setting of dialysis-dependent renal failure due to diabetes; simultaneous combined kidney and pancreas transplantation is performed with the total pancreas implanted into the bowel and with venous drainage into the portal system. The long-term risks and constraints of chronic diabetes with renal failure must be weighed against the risks of a complex surgical procedure, significant post-operative complications, and the need for long-term immunosuppressive therapy.

Simultaneous pancreas-kidney transplantation utilizing a common arterial conduit: early experience and potential applications

Simultaneous pancreas-kidney transplantation has gained acceptance as a therapeutic modality for patients with end-stage renal disease secondary to diabetes mellitus. In some instances, performing the procedure as conventionally described with renal revascularization from the left iliac vessels and pancreatic arterial inflow from the right iliac vessels may be difficult or undesirable. We describe our experience with an alternate operative technique utilizing a single arterial conduit to vascularize both organs. We believe that this technique may be of use in certain patients undergoing simultaneous pancreas-kidney transplantation.