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?
It is important to note that the pancreas, in addition to having an "endocrine" function (i.e., the production of hormones such as insulin, which are released into the bloodstream), also has an "exocrine" function, i.e., the production of pancreatic juices necessary for the digestion of foods. Pancreatic juices are released directly into the intestine, more specifically into the part of the intestine known as the duodenum.
The organ is transplanted to a different anatomical location than usual (heterotopic transplantation). The pancreas will be transplanted along with a portion of the donor's duodenum.
The intervention is performed under general anesthesia. After induction (anesthesia), the skin of the abdomen will be disinfected and the bladder catheter will be placed.
The surgical incision will be made on the abdomen. The location of the pancreas in the abdomen will be chosen at the time of surgery, based on the characteristics of the organ to be transplanted and the shape of the patient's abdomen.
The new pancreas will need to be connected to an artery and vein to ensure blood circulation and thus the organ's viability.
There are two options. The most common one is the pancreas positioning in the right flank, "lacing" the organ to the right iliac artery and vein. The second is the placement of the pancreas in the center of the abdomen, so that the venous blood coming out of the transplanted organ goes directly to the liver, as is physiologically the case for the pancreas itself.
In both options, the duodenum of the transplanted pancreas will be joined to the recipient's intestine to deliver pancreatic fluid produced by the exocrine portion of the transplanted pancreas.
At this point, the surgery will conclude with the placement of a drainage tube that will be used in the post-operative period to monitor what is happening in the transplanted pancreas. After a few days, the abdominal drain and bladder catheter will be removed.
Upon awakening, the patient will have a central venous catheter necessary for the administration of intravenous therapy and for hydration by IV. 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, the patient will remain connected to a heart monitor, which will assist medical and nursing staff in monitoring vital parameters. The patient will begin to move and feed himself as soon as possible, always according to the instructions of doctors and nurses. Advice at discharge should indicate monitoring of specific blood tests and urine culture (once a week for two weeks then once every 15 days for 1 month then once a month every month). After discharge, the patient will have outpatient follow-up visits to the transplant clinic. The frequency of visits is established according to clinical progress and the onset of any complications. The visits tend to be carried out in relation to the frequency of blood tests 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 and include: a) early venous thrombosis of the transplanted pancreas with removal of the same, pancreatic fistula, duodenal stump dehiscence, wound infection and dehiscence, macroscopic hematuria, intra-abdominal urinary fistula, reflux pancreatitis, recurrent urinary tract infections, small bowel obstruction, abdominal abscesses (transplant thrombosis).
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.