Surgeon Inserting Tube Into Patient During Surgery

By: Basia Cybart

The islets of Langerhans or islets are irregularly shaped patches of endocrine tissue located in the pancreas, containing insulin producing beta cells. In type 1 diabetes, beta cells stop producing insulin which results in glucose being no longer absorbed from the blood.

There are options available to type 1 diabetes patients to manage this condition such as, insulin injections. Insulin injection lower blood glucose levels and need to be administered at least once a day by syringe, pump, or pen. Though, this method is relatively easy to apply, it necessitates having to insert a needle into a body part, be it the abdomen, arms, legs or buttocks, which is not done without some degree of discomfort. Also, insulin injections may need to be administered in public which can be uncomfortable.  However, this is the only way to control the blood glucose level of type 1 diabetes patients.

Or, it was, until the Edmonton Protocol was introduced.

 

In the 1960’s Paul Lacy developed islet isolation and transplantation. Paul Lacy’s work was then utilized by the doctors at the University of Alberta Hospital and the Surgical-Medical Research Institute; Dr. James  Shapiro (transplant surgeon), Jonathan Lakey Ph.D., Dr. Edmond Ryan (endocrinologist), Gregory Korbutt Ph.D., Dr. Ellen Toth, Dr. Garth Warnock, Dr. Norman Kneteman, and Ray Rajotte Ph.D. whose discoveries were published in the New England Journal of Medicine in the June 2000 issue under the heading: ‘International Trial of the Edmonton Protocol for Islet Transplantation’.

The Edmonton Protocol is the procedure applied when transplanting cadaveric 1 pancreatic islets into type 1 diabetes patients. The islet transplant begins with islets being removed from the donor pancreas through the use of specialized enzymes. As islets are fragile tissues, they must be transplanted soon after removal. Typically, a patient would receive 10 000 islet “equivalents” per kilogram of body weight, extracted from two to three donor pancreases. The transplants are performed by a radiologist, who inserts a catheter 2 into the portal vein of the liver. The islets are then infused into the liver by the catheter and begin to release insulin shortly after transplantation. However, full islet function and the accompanying blood vessel growth take more time. Until full islet function is achieved insulin is administered to the patient. 3 4 Patients generally require two islet transplants to achieve full insulin independence.

In 2005, the researchers of the Edmonton Protocol published 5-year follow-up results for 65 patients who underwent islet transplants and reported that about 10% of the patients remained insulin independent at the 5-year follow-up. The remaining 90% of the islet transplant recipients resumed using insulin because the transplanted islets stopped functioning over time. Although, the researchers noted many were able to reduce their need for glucose, achieve better glucose stability, and reduce problems with hypoglycaemia.

Undergoing the Edmonton Protocol procedure benefits type 1 diabetes patients in a variety of ways. One of the more important advantages is improved glucose control which can prevent the progression of complications associated with diabetes, such as heart disease, kidney disease, and nerve or eye damage.

As with any surgery, there not only benefits associated with an islet transplant but risks as well; rejection of the islets and the dangers of using immunosuppressant drugs (mouth sores, stomach upsets, diarrhoea, increased blood cholesterol levels, hypertension, anemia, fatigue, decreased white blood cell counts, decreased kidney function, and increased susceptibility to bacterial and viral infections, as well as tumours and cancer). Another obstacle, specifically associated with islet transplant surgery is the shortage of islets. Researchers are already working to surmount this complication by attempting to use stem cells to grow islets in laboratories.

Regardless of the risks, the Edmonton Protocol and islet transplant surgery is bringing the world closer to a cure for type 1 diabetes.

To learn more about the Edmonton Protocol please click on the link below.

Edmonton Protocol celebrates 10th anniversary

Notes:

  1. Cadaver: a dead body; especially : one intended for dissection – cadaveric adjective (Merriam Webster
  2. Catheter:  a tubular medical device for insertion into canals, vessels, passageways, or body cavities for diagnostic or therapeutic purposes (as to permit injection or withdrawal of fluids or to keep a passage open) (Merriam Webster)
  3. National Diabetes Information Clearinghouse (NDIC)
  4. Hypoglycemia: abnormal decrease of sugar in the blood

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