IMPLANTED PROGRAMMABLE INSULIN PUMPS - 153 PATIENT YEARS OF SURGICAL EXPERIENCE

Background. Implanted insulin pumps (IIPs) are an alternative treatmen t for diabetes mellitus. To maintain good glycemic control, patients w ith an IIP require frequent surgical interventions. Methods, Since Nov ember 1986, 21 patients with insulin-dependent diabetes mellitus at th e Johns Hopkins Hospital have undergone implantation of pumps subcutan eously with a catheter delivering insulin into the peritoneal space. P atients were followed up with self-monitoring of blood glucose levels two to four times daily and percutaneous refills of the pump with U-40 0 insulin every 6 to 12 weeks. Results. In 153 patient-years, 77 pumps were placed. The mean pump life was 29 +/- 2 months. Morbidity was li mited to pump site infections (3.9%) and one small bowel obstruction. Inadvertent insulin overdelivery has never occurred. Episodes of insul in underdelivery were caused by backflow anomalies (n = 67), which wer e cleared by percutaneous rinses, or catheter obstructions (n = 12), w hich required catheter replacements. Ninety-one operations were requir ed to maintain pump function. All patients are alive and report improv ements in quality of life. Significant reductions in hemoglobin A1C an d plasma glucose levels were also seen. Conclusions. Long-term use of IIPs results in significant improvements in clinical parameters and qu ality of life for individuals with insulin-dependent diabetes mellitus . Relatively frequent operations are required for maintaining pump fun ction, which are done with a local anesthetic with minimal morbidity.