Simultaneous pancreas-kidney and sequential pancreas-after-kidney transplantation

Abstract

Simultaneous pancreas-kidney (SPK) or pancreas-after-kidney (PAK) transplantation has been advocated as an alternative to kidney transplant alone (KTA) for type 1 diabetics with end-stage renal disease. Advocates of combined transplant assert that the procedure reduces, prevents, or mitigates secondary complications of diabetes and improves the quality of life (QOL) of recipients. The combined procedures may be accomplished with a relatively low mortality, but the morbidity significantly exceeds that of KTA. The published data did not provide unambiguous support for the contention that SPK or PAK improved or ameliorated the secondary diabetic complications of retinopathy, neuropathy, and nephropathy, and it cannot be reasonably concluded that such benefit is likely to result. The majority of studies of QOL subsequent to combined transplant had significant methodologic deficiencies which made generalizations problematic. Notwithstanding, improvements in objective measures, such as return to employment or school, reduction in medical care requirements, days spent in hospital, social or physical activity, etc, have not been demonstrated for combined transplant; improvements in subjective measures were inconsistently reported. The United Network for Organ Sharing (UNOS) registry indicated that SPK represents 83 percent, and PAK about 8 percent of all pancreas transplants in the United States. Pancreas graft survival data are limited; UNOS reported 3-year survival rates of approximately 65 percent following SPK, and 35 percent after PAK. Renal graft survival following SPK appears comparable to that reported for most cadaver KTA. However, selection of SPK in lieu of KTA with a living-related donor or HLA-matched cadaver kidney may result in significant reduction in expected renal graft survival, in the range of 40-70 percent to as much as 350 percent. A cost-effectiveness analysis (CEA) model compared SPK with KTA and continued insulin therapy. The model employed a wide range of reported charges/payments, and postulated that SPK would provide significant improvements in quality of life. Sensitivity analyses indicated that SPK was equal in cost effectiveness to KTA only in patients who incurred very high annual costs for the treatment of hyper- or hypoglycemia. The literature does not indicate that such patients comprise the majority of SPK recipients. Additional evidence is necessary to unequivocally demonstrate the risks, costs, and ultimate benefits of combined transplant. Such information should include detailed and unambiguous patient selection criteria, prospective comparative studies of the effects of SPK/PAK upon secondary complications and quality of life, and accurate cost data for the transplant procedures and required followup care.