Hypertension after pancreas-kidney transplantation: role of bladder versus enteric pancreatic drainage

Long-term Effects of Pancreas Transplantation on Diabetic Retinopathy and Incidence and Predictive Risk Factors for Early Worsening

BACKGROUND

Limited data are available regarding the long-term effects of pancreas transplantation on the progression of diabetic retinopathy (DR) and the incidence and associated risk factors for early worsening of DR.

METHODS

Patients who underwent successful pancreas transplantation between January 2007 and October 2015 and were followed for 1 year or longer were consecutively enrolled. Variables regarding demographic, systemic, metabolic, and surgical factors were reviewed for each patient. DR progression was defined as (i) development or aggravation of macular edema requiring intravitreal anti-VEGF injections and/or (ii) progression of DR severity requiring panretinal photocoagulation (PRP) and/or pars planar vitrectomy (PPV). Early worsening was defined as progression within 1 year of posttransplant.

RESULTS

Three hundred three eyes of 153 patients were included in the analysis. At the pretransplant ocular evaluation, 221 eyes (72.9%) showed advanced DR with history of PRP and/or PPV. During a mean follow-up period of 4.2 years, 62 eyes (20.5%) experienced DR progression, and early worsening was noted in 57 eyes (18.8%). DR with recent PRP within pretransplant 1 year and pancreas transplant alone were significant risk factors for early worsening.

CONCLUSIONS

In 4 of 5 patients who received pancreas transplant, the degree of DR remained stable over time after transplantation. Meanwhile, early worsening of DR could occur in patients at risk, particularly within the first posttransplant year. We suggest that physicians should have a high index of suspicion and carefully monitor for early worsening of DR and timely manage possible ocular deterioration.

Pancreas transplantation: indications and consequences

Pancreas transplantation continues to evolve as a strategy in the management of diabetes mellitus. The first combined pancreas-kidney transplant was reported in 1967, but pancreas transplant now represents a number of procedures, each with different indications, risks, benefits, and outcomes. This review will summarize these procedures, including their risks and outcomes in comparison to kidney transplantation alone, and how or if they affect the consequences of diabetes: hyperglycemia, hypoglycemia, and microvascular and macrovascular complications. In addition, the new risks introduced by immunosuppression will be reviewed, including infections, cancer, osteoporosis, reproductive function, and the impact of immunosuppression medications on blood pressure, lipids, and glucose tolerance. It is imperative that an endocrinologist remain involved in the care of the pancreas transplant recipient, even when glucose is normal, because of the myriad of issues encountered post transplant, including ongoing management of diabetic complications, prevention of bone loss, and screening for failure of the pancreas graft with reinstitution of treatment when indicated. Although long-term patient and graft survival have improved greatly after pancreas transplant, a multidisciplinary team is needed to maximize long-term quality, as well as quantity, of life for the pancreas transplant recipient.

Pancreas and kidney transplantation

Kidney transplantation is preferred over dialysis for management of end-stage renal disease complicating type I or type 2 diabetes, for those who are eligible. Simultaneous pancreas-kidney (SPK) or pancreas after kidney transplantation (PAK) is an important alternative to kidney transplantation alone for type I diabetes patients if the patient is able to withstand the additional risks of these procedures, because of the benefits of glucose control on other diabetic complications. Pancreas transplantation alone (PTA) is most useful for the treatment of debilitating, frequent hypoglycemia complicating type I diabetes, if renal function is adequate. One-year pancreas graft survival is best after SPK (82%) but has significantly improved after both PAK (74%) and PTA (76%). The I-year kidney graft and patient survival rates after SPK are similar to kidney transplantation alone. Pancreas transplantation normalizes glucose beyond what can be achieved with insulin therapy and has been shown to decrease progression of or improve most, if not all, diabetic end-organ complications using current immunosuppression regimens. However, the diabetologist and endocrinologist should remain involved in the care of the pancreas or kidney transplant recipient for treatment of vascular disease risk factors such as dyslipidemia, surveillance of other diabetic complications including foot ulcers, surveillance and treatment of bone loss, and management of hyperglycemia if it recurs.

Trends and perspectives in pancreas and simultaneous pancreas and kidney transplantation

Pancreas transplantation is still the best option to achieve normoglycaemia and insulin independence in patients with type I diabetes. As a result of improvements in surgical techniques, immunosuppression and patient selection, one year survival rates of 95, 83, and 88% for patient, pancreas, and kidney survival, respectively, are reported for patients with simultaneous pancreas and kidney transplantation. The main goals for the future are to reduce postoperative morbidity, to identify the relevant indications for single pancreas transplantation, to adopt the best surgical technique for individual patients' needs (bladder versus enteric drainage with or without portal venous delivery of insulin), and to develop immunosuppressive strategies with low nephrotoxic and diabetogenic potential.