Using a 13-year nationwide database, a cohort of 1,568 children younger than 5 years of age who received VPS were followed up for IH. Of these, 194 received IH repair. Kaplan-Meier analysis and Cox regression were conducted.
Overall incidence of IH after VPS in children younger than 5 years old was 22.9 per 1,000 person-years. The average follow-up time was 5.41 years, and the mean time interval between VPS and IH repair was 1.14 years. Age-specific incidences were 45.0, 21.3, 18.5, and 4.1 per 1000 person-years for neonates, infants, toddlers, and preschool children, respectively. Compared with preschool children, neonates, infants, and toddlers, were more likely to have IH (crude hazard ratio = 9.8, 5.3, and 4.4; p < 0.001, p = 0.001, and p = 0.006, respectively). Sex and age were significantly different in children with and without IH (both, p < 0.001). Differences of cumulative incidence rates in the 4 age groups were significant in both male and female patients (p < 0.001 and p = 0.023, respectively).
The patient's age on VPS surgery significantly affects the likelihood of subsequent IH development. IH is more likely to develop in neonates after VPS than in infants, toddlers, and preschool-aged children. This age-related effect is more prominent in boys than in girls.