Surgical Procedure
An islet transplant begins with organ donation by someone who has had an accident or medical event that has led to brain death. The donor's family has made the decision to donate the organs of their family member for transplant.
The Islet Transplant Team at Emory receives the donated pancreas and carefully separates the islets from the rest of the pancreas. This process of “islet isolation” takes a team of five highly trained researchers up to 10 hours.
A patient who has been carefully screened by Emory and is eligible to receive an islet transplant is contacted by an Emory “transplant coordinator”. The coordinator provides instructions for coming to Emory University Hospital for the potential transplant. If the islet isolation goes well and there are enough islets to complete the transplant, the patient is prepared for surgery. The islet transplant procedure takes place in the operating room using general anesthesia. Once the patient is anesthetized (put to sleep) the surgeon makes a 2-3 inch incision in the abdomen. A plastic catheter is placed into a vein that leads to the liver. The islets are infused into the vein over a 5-15 minutes period. Once the infusion is completed, the incision is closed, and the recipient is awakened and transported to the recovery room. The islets gradually begin to produce insulin and to regulate the glucose levels in the blood.
Because it is difficult to isolate all of the islets from a pancreas most people will need two transplant procedures in order to become completely free of insulin injections. However, most islet transplant recipients require less daily insulin and experience more stable blood sugar levels after the first transplant.
Preparing the Islets
The isolation procedure must begin within hours after the organ is procured, which can be at any time of the day or night. The processing takes place in the Emory Islet Isolation Laboratory, and requires a team of 4-5 people.
Isolating and preparing the islets for transplant takes 8-12 hours. A catheter is placed into the ductal system of the pancreas and an enzyme is injected into the gland. The enzyme breaks down the connections between the cells of the pancreas. The pancreas is placed into a special chamber with marbles. Fluid is pumped into and out of the chamber as it is shaken. The pancreas is completely broken down into very tiny pieces of tissue. The islet tissue is separated from rest of the pancreatic tissue and the islets are counted. If there are a sufficient number of islets isolated they are prepared for transplant and the patient is prepared for surgery. If there are not enough islets in the final count, the transplant will be cancelled and the patient is sent home. A patient could be called to the hospital several times before receiving a transplant since the number of islets available is not known until the end of the isolation process.
The Transplant
The patient will be given the first dose of immunosuppressants right before the first transplant procedure. The transplant procedure takes place in the operating room and is performed by a transplant surgeon. General anesthesia is used so that the patient is asleep for the entire procedure.
The abdomen is washed with disinfectant and draped with sterile towels. The surgeon makes an incision in the abdomen. A catheter (thin plastic tube) is placed into a vein, and the bag containing the islets is attached to this catheter. The islets flow into the vein and are carried by the blood flow into the liver, where they lodge in smaller veins and capillaries. The infusion takes 5 to 15 minutes; the entire surgery takes only about one hour.
Once the islet infusion is complete, the catheter is removed and the incision is closed using sutures or staples. Once the patient is awake, he or she is transported to the recovery room and monitored for about one hour. After returning to the hospital room, the nursing staff continues to monitor the patient's vital signs and blood sugars frequently. After about six hours blood is drawn for lab work. An abdominal ultrasound is performed within 24 hours after the transplant to check the liver for bleeding around the blood vessel where the islets were infused. If all of the test results are satisfactory, the patient is discharged from the hospital 2 days after the transplant.
