Pancreatic Islet Transplantation
When is this procedure indicated?
The indications for pancreatic islet transplantation are the same as those reported for pancreas transplantation, with the following peculiarities:
- Islet transplantation associated with kidney transplantation in type 1 diabetic patients with chronic renal failure on dialysis or pre-dialytic phase or kidney-only transplant recipients who, due to cardiovascular complications, have been contraindicated to simultaneous kidney-pancreas transplantation.
- Isolated islet transplantation in type 1 diabetic patients who meet the characteristics set forth by the Italian Society of Diabetology and the American Diabetes Association, as for full pancreas transplantation: history of frequent and acute complications of diabetes, such as hypoglycemia, hyperglycemia, ketoacidosis requiring medical intervention, reduced sensitivity to hypoglycemia, and consequent difficulty in conducting normal activities of daily living and a high risk of hypoglycemic coma, clear failure of insulin therapy in preventing acute complications of diabetes, in particular hypoglycemia. Pre-transplant assessment: for islet transplantation, cardiovascular issues are not an absolute contraindication. The presence of active liver diseases (e.g. chronic viral or autoimmune hepatitis, cirrhosis) is a contraindication.
How is it performed?
The transplant procedure is a simple infusion of the islets into the liver. The maneuver is performed by the interventional radiologist specialist, in the angiographic room, under local anesthesia combined with mild sedation, according to the following schedule:
insertion under ultrasound guidance of a vascular catheter with a diameter of a few millimeters in the portal vein of the liver through direct puncture of the abdomen, near the right costal arch;
control of the correct positioning of the vascular catheter with injection of contrast medium and execution of portography, which allows to verify the location of the catheter and the absence of vascular abnormalities in the portal circle;
connection of the vascular catheter with the syringe containing the islands diluted in physiological saline;
removal of the vascular catheter and injection of biocompatible material to occlude the passage of the catheter in order to prevent possible bleeding. At the end of the transplant procedure, the patient must remain fasting and in bed for 8 hours; after this short interval of time, the patient can resume normal activities such as walking and eating.
The patient can be discharged on the 8th day in the absence of complications, after some hematochemical control tests for the evaluation of hepatic necrosis and coagulation, and instrumental examinations, such as liver ultrasound and echodoppler of the portal vein to exclude the presence of hematomas or thrombosis. From the moment of discharge, the patient will be checked at the Outpatient Clinic of the Transplant Center according to the following schedule: examination and blood draws in the first 4 weeks after the infusion and monthly until 12 months after the last infusion. Then checks will continue every three months. Metabolic control tests are carried out in the outpatient clinic in 1-3-6-12 months from the last infusion, and then annually. Hospitalization for post-transplant instrumental control of complications of immunosuppressive therapy and diabetes is scheduled on the 12th month after the first infusion and then annually.
The main risks are local bleeding at the injection site and thrombus formation in the portal vein.
The experience gained in the last 20 years in this field has shown that the liver does not develop problems of function after islet transplantation, neither in the short nor in the long term, even in cases of multiple infusions.