Optimal routes for chronic insulin infusion with portable and implantable devices

The optimal route for chronic insulin infusion via portable or implantable pumps is still a subject of controversy. Through the literature reports and personal experience (representing 70 patient-years of continuous treatment), the authors have found that the subcutaneous route is the ideal route in terms of comfort, safety, and cost. However, owing to sluggish and unpredictable insulin resorption, it appears that subcutaneous infusion is often not more effective than intensive conventional insulin therapy. The intravenous route gives the best diabetic control, but with a high risk of infection and obstruction. The intramuscular route, although more efficient than the subcutaneous, can be envisaged for only short periods because of its poor tolerance. The portal route is still at an experimental stage. The authors chose the intraperitoneal route because of the following advantages: near physiological insulin resorption kinetics; better diabetes control than subcutaneous infusion although comparable to intravenous; a 30% reduction of insulin requirements; and satisfactory local tolerance and acceptability with respect to severe asepsy precautions, patient selection, intensive education, and careful medical follow-up. The intraperitoneal route is feasible for portable insulin pumps, but basically more adaptable to implantable devices.