Persistent hyperinsulinemic hypoglycemia of infancy: Long-term outcome following subtotal pancreatectomy

Background: Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is the most common cause of persistent hypoglycemia in infants. The current standard treatment is subtotal pancreatectomy (Px). However, the long-term outcome following surgery needs further attention. Methods: We analyzed 10 children (7M, 3F) with PHHI who underwent partial (65-80%) and subtotal (81- 95%) Px. Follow-up ranged from 2 to 9.4 yr (mean = 4.2 yr). We divided them into 2 groups based upon the age at onset of hypoglycemia: early (< 1 mo) and late (≥ 1 mo). Results: The seven patients in the early-onset group underwent 85-95% Px between ages of 18 d and 3 mo. Three of them initially treated by 85-90% Px had persistent hypoglycemia postoperatively. Two out of three required a 2(nd) operation with 95% Px for controlling hypoglycemia, though both still had persistent hypoglycemia and required medication to control blood glucose. The remaining four had 95% Px and had maintained euglycemia postoperatively. One patient developed diabetes 6 yr after surgery. Six of seven patients had delayed development and subnormal IQ. Three patients of the late-onset group (3 mo, 6 mo and 4 yr) underwent partial Px (80%, 65% and 65%, respectively) and maintained euglycemia postoperatively. Despite 65% Px, one developed diabetes 3 yr after surgery. Conclusions: These results suggest that children with early-onset hypoglycemia have more severe hyperinsulinism than those with late-onset hypoglycemia. The former require 95% Px for maintaining euglycemia, but long- term complications with diabetes may be common. In contrast, the latter require lower percentage Px which may reduce the incidence of diabetes in the future.