Canadian surgeons transplanted islet cells from a pancreas perfused with blood for 124 minutes after circulatory arrest

Canadian surgeons transplanted islet cells from a pancreas perfused with blood for 124 minutes after circulatory arrest

On July 24, a Canadian team reported a single clinical case. After confirming the donor's circulatory death, the team restored blood flow to the abdominal organs, isolated 400 thousand islet equivalents from the pancreas, and infused them into a 69-year-old patient with type 1 diabetes.

Pancreatic islets produce insulin. Clinicians isolate them from a donor pancreas and infuse them into people with type 1 diabetes who can no longer detect dangerously low glucose levels. After circulation stops, the tissue rapidly depletes its energy reserves. The islets must then survive enzymatic digestion and mechanical processing in the laboratory.

In a paper published on July 24, physicians in Vancouver described how they connected the donor's aorta and inferior vena cava to a normothermic regional perfusion system after the mandatory five-minute waiting period. For 124 minutes, the system circulated oxygenated blood through the abdominal organs at body temperature. The surgeons occluded the section of the aorta supplying the brain.

This restored blood flow to the tissues before the pancreas was cooled. The donor's lactate level, which rises when oxygen is scarce, declined, while glucose remained stable. The pancreas was then cooled and transferred to the laboratory.

The team obtained 400 thousand islet equivalents from the pancreas. This is the standard measure of islet tissue volume. The cells retained 92% viability, and the yield was sufficient for one infusion. The donor had a low body mass index, which usually reduces the yield of islet tissue.

Four weeks after transplantation, the patient had reduced her daily insulin dose from approximately 21 to 6–7 units. Her time within the safe glucose range increased from 74% to 96%, while her time below 3.9 mmol/L fell from 24% to 3%. Her blood C-peptide level increased from 184 to 832 pmol/L. C-peptide is released together with insulin produced by the transplanted tissue.

Normothermic regional perfusion is already used when recovering livers and kidneys after circulatory death. In Vancouver, physicians applied it to the pancreas. They restored oxygen delivery to the organ before cooling it, isolated its islet cells, and transplanted them into a patient.