A remotely programmable insulin delivery system. Successful short-term implantation in man.
A remotely controlled, programmable insulin delivery system was implanted in a diabetic man and the feasibility of the technique was examined. Specific problems included (1) development of an appropriate surgical approach, (2) identification of methods to assess the integrity of the insulin delivery system following implantation, and (3) assessment of plasma glucose and free-insulin profiles obtained with the implanted system. The insulin pump was implanted submuscularly through a midline abdominal incision. The insulin reservoir was placed subcutaneously to allow percutaneous refilling. The insulin delivery catheter terminated in the peritoneal space. No postoperative wound infection occurred and rapid healing of the surgical site ensued. In vivo assessment of the system included (1) dye contrast roentgenography, (2) vasopressin stimulation, and (3) reservoir volume monitoring. Short-acting insulin was then placed in the implanted reservoir and delivered by the system for one month. Mean plasma glucose concentration declined to normal levels, as did glycosylated hemoglobin. Plasma insulin profiles were normalized with appropriate insulin peaks with each meal. We conclude that implantation of a remotely programmable insulin pump is feasible in type I diabetic man. Additional studies are necessary to define which patients will benefit from this type of insulin delivery system.