How is an islet tranplant performed?
Islets transplanted into people with diabetes come from the pancreas of a deceased organ donor. An overview of the process is shown below. The islets are isolated from a decreased donor's pancreas and infused into the recipient's liver via the portal vein. The transplanted islets then produce insulin in response to sugars found in the blood as it flows through the liver.
A number of critical steps must be taken in a timely fashion to complete an islet transplant.
- The donor pancreas is obtained by a highly skilled group of physicians. The University of Minnesota has a dedicated team on call to obtain pancreases.
- The pancreas is brought to a facility the University of Minnesota whose purpose is to make biological products such as human islets. At this facility, staff members isolate and purify the islets. This process takes more than six hours.
- The pancreas is cut into small pieces and put in a special container with steel marbles. The container is shaken, and enzymes are added to break down the tissue so the islets are freed from the rest of the tissue.
- The islet tissue cells are removed, washed, counted and checked to be sure they are not damaged. On average, approximately 500,000 of the 1 million islets in a pancreas can be retrieved. This number of islets can usually maintain normal blood sugar levels. If the number or quality of islets is not satisfactory, the transplant must be cancelled.
If the number or quality of islets is satisfactory, the islets are cultured for two days before transplant.
Islet transplantation is a usually done in the radiology (X-ray) department and it takes 30 minutes to 2 hours. The recipient receives some sedation but remains awake. Islets are put into the body through a catheter (tube) in a vein of the liver. This vein is called the portal vein. The catheter can be placed in two different ways. The study doctors will decide which way would be safest for you. The two possible ways are:
- Placement of islets through a needle going through the skin into the liver. If you have this procedure it will be done in an x-ray room. You will receive medication to sedate you and medication to numb an area on your right side between two ribs. The doctor will insert a needle into your liver. A computed tomography (CT) scan or an ultrasound will be used to help the doctor get the needle into the portal vein. A kind of dye will be injected to make sure that the catheter is in this vein.
- Placement of the islets through a small cut in the skin. If you have this small operation, you will receive a medication to sedate you and a local anesthetic (numbing medicine) will be injected into your upper abdomen. A cut (no longer than two inches) will be made and the catheter will be inserted into a branch of the portal vein. If you receive your islets in this way, after all the islets have been given, the catheter will be removed and the cut will be closed with stitches that will dissolve when the cut is healed.
Recipients recover quickly from the procedure and are typically discharged from the hospital 2-3 days after the infusion. To monitor the patient's health status and to determine how the islets are functioning, the islet transplant recipient will have to visit the University of Minnesota numerous times in the first year post-transplant as an outpatient. A second or third islet transplant is considered if the first does not stop the need for insulin injections or if blood glucose control is not well managed.
What are the risks associated with islet transplantation?
There are two main types of risks: 1) those associated with the procedure itself and 2) those associated with the use of anti-rejection drugs, which can weaken the immune system. We are, however, working on an immunosuppression protocol that minimizes these negative effects.
What is the success rate of islet transplatation over management of Type 1 Diabetes with insulin injection?
Islet transplantation is primarily for those whose diabetes cannot be managed with insulin injection. Of our islet transplant recipients, all had suffered from hypoglycemia unawareness that persisted despite intensive efforts to control the episodes. None of our islet transplant recipients have experienced a serious, unexpected adverse event related to the transplant procedure or the immunosuppression protocol. 90% of recipients were insulin-independent post-transplant, and 50% were insulin-independent after 5 years.
What if I'm not eligible for an islet transplant?
Please call the Schulze Diabetes Institute for further screening. We are continually working on expanding our criteria so that this treatment can be available to all who need it. If you are not eligible for an islet transplant at this time, you may want to consider a pancreas transplant.
Is this treatment available to children?
Currently, you must be age 18 or older to receive an allo-islet transplant (islets from a donor pancreas). However, auto-islet transplants (transplantation of a patient's own islets into the liver) are used to treat children suffering from chronic pancreatitis.
How many follow-up visits are required and must they be conducted at the University of Minnesota?
Between 13 and 16 follow-up visits are necessary after transplantation. Currently these must be performed at the University of Minnesota, but in the future it is possible that a portion of these visits may be conducted by your own physician.
What do follow-up visits entail?
The Islet Transplant Research team provides care for blood glucose management and immunosuppression dosing. All other medical care, including potential side effects of drugs, will be provided by your primary care physician, endocrinologist, and/or other specialists.
Does insurance cover this procedure?
At this time, islet transplantation is considered an experimental treatment, so you will need to check with your individual insurance provider. Our experienced staff at Schulze Diabetes Institute can walk you through this process. Specifically, the anti-rejection drugs are paid for during the length of the clinical trial. You will need to check with your insurance carrier to find out if the drugs are covered after the trial period.