When is this procedure indicated?
The indications for pancreas transplantation have been defined by the Italian Diabetes Society (SID) on the basis of the indications of the American Diabetes Association (ADA), and include:
- Pancreas and kidney transplantation advisable in patients with type 1 diabetes and chronic renal failure undergoing dialysis treatment or in the pre-dialytic phase.
- Isolated pancreas transplantation is advisable, after exclusion of the presence of contraindications and verification of a preserved renal function, in people with type 1 diabetes with history of frequent and acute complications of diabetes (hypoglycemia, hyperglycemia, ketoacidosis), reduced sensitivity to hypoglycemia with high risk of hypoglycemic coma, clinical and emotional problems towards insulin therapy, so severe that its leads to disability and evident failure of insulin therapy in preventing acute complications of diabetes. The organ to be transplanted comes from a cadaveric donor and is assigned based on compatibility for blood types (A, B, O, AB).
How is it performed?
Pancreas transplantation can be isolated or combined with kidney transplantation. More rarely, pancreas transplantation is reported following kidney transplantation, often when the latter was obtained from a living donor. Pancreas transplantation is performed under general anesthesia.
After skin disinfection and prior placement of bladder catheter, central venous catheter (CVC), laparotomy, exploration of the peritoneal cavity with choice on the best placement of the organ is performed under general anesthesia. This depends on the anatomical characteristics of recipient and donated organ. The organ is placed in a different site from the natural site (heterotopic transplantation). The artery is anastomosed to the right iliac (common or external) and venous artery with the ipsilateral vena cava or iliac vein. An anastomosis is then packed between the donor's duodenum and the recipient's jejunum to ensure drainage into the intestine of pancreatic juices.
During the procedure, the patient undergoes invasive and continuous blood pressure monitoring, which combined with constant central venous pressure monitoring allows for the best hemodynamic conditions for perfusion of the transplanted organ.
Upon awakening, the patient will have a central venous catheter needed for the administration of intravenous therapy and hydration by drip. A bladder catheter, which will be removed as soon as possible, and, if necessary, one or more abdominal drains will be placed in the operating room. For a few days it will remain connected to a cardiac monitor, which will help medical and nursing staff in monitoring vital parameters. The patient will begin mobilization and feeding as soon as possible, however, always according to the instructions of doctors and nurses. Discharge counseling should indicate monitoring of specific blood counts and urine culture (1 time a week for two weeks then 1 time every 15 days for 1 month then 1 time a month every month). After discharge, the patient performs outpatient follow-up visits at the transplant clinic. The frequency of visits is determined according to clinical progress and the occurrence of any complications. Visits tend to be made in relation to the frequency of blood counts and therefore 2 times a week within the first 15 days after discharge, once a week in the following month, and finally monthly.
Early complications affect 10-15% of patients.
Surgical complications: bleeding with possible intraperitoneal hematoma formation, infection, vascular thrombosis (5-12% of cases), dehiscence of the duodenojejunal anastomosis, cardiovascular or respiratory complications (the latter being characteristic of all major surgery). Vascular thrombosis, diagnosable on echo-color-doppler or CT scan with intravenous contrast medium, may be partial or complete. While anticoagulant therapy is imposed in partial thrombosis, in the second case it may be necessary to explant the transplanted organ in the days following transplantation. Thus, reintervention is reserved for cases in which conservative treatment is not feasible given the complication. Another possible complication of pancreas transplantation is intestinal occlusion, due to the natural formation of postoperative intra-abdominal adhesions. Based on the type of occlusion, a decision is made whether to undertake conservative treatment (with placement of nasogastric tube for detention and intravenous nutritional support) or whether surgical reintervention is necessary. In the case of simultaneous kidney-pancreas transplantation, we also recognize hematuria and urinary fistula as complications. Another common complication of this type of transplantation is lymphocele, which is the collection of lymphatic fluid at the site of vessel preparation. Such collection in most cases has a tendency to spontaneously exhaust itself, while in a limited number of cases it requires keeping surgical drainage in place for a longer time or, even more rarely, surgery using a minimally invasive technique to drain it.
The most common late complications are related to rejection and increased risk of infection. Suspicion of rejection is raised, as in the case of pancreatitis, when there is an increase in plasma amylase and lipase, or hyperglycemia.
Radiologic examinations with contrast medium (e.g., CT) may be necessary to study the pancreas at this stage. The diagnosis of rejection is confirmed by ultrasound-guided biopsy of the transplanted organ. Sometimes a laparoscopic procedure (a surgical procedure that involves small incisions that allow the insertion of instruments to perform the biopsy) is required to perform the biopsy.