O2172: Inguinal Hernia Recurrence in Premature Infants is Not Affected by Timing of Repair

Background: While previous studies suggest that delaying inguinal hernia repair in premature infants reduces the risk of anesthesia-related complications, the optimal timing for surgery in relation to hernia recurrence remains unclear. Our study aims to compare recurrence rates of inguinal hernias repaired before and after 55 weeks postmenstrual age (PMA).

Methods: A retrospective chart review was conducted on premature infants who underwent inguinal hernia repair at < 1 year of age between 1/2017-12/2019 across 21 Children’s Hospitals. Demographics, clinical characteristics, perioperative details and postoperative outcomes were collected. Patients with cryptorchidism were excluded. Our primary outcome measure was inguinal hernia recurrence, defined as recurrence requiring surgical re-repair. Data was analyzed using descriptive and inferential statistics with significance defined as p< 0.05. Event count was determined by hernia rather than patient, counting unilateral hernias as one and bilateral hernias as two. Multivariable logistic regression was performed to identify factors associated with recurrence.

Results: A total of 3,812 hernias met inclusion criteria: 3,296 (86.5%) hernias underwent early repair before 55 weeks PMA and 516 (13.5%) hernias underwent late repair after 55 weeks PMA. Median PMA at the time of repair was 43.0 weeks [IQR 39.6, 46.7] for the early group and 61.4 weeks [IQR 57.7, 66.8] for the late group (p < 0.001). The early group weighed significantly less than the late group (4.0 kg vs. 7.1 kg, p< 0.001). Majority of patients were male in both groups (Table 1). A lower percentage of the early group had comorbid conditions at the time of repair compared to the late group. There were no differences in hernia laterality, preoperative hernia reducibility, operative approach or need for bowel resection between the two groups (Table 2). In the early repair group, 264 (9.4%) were incarcerated compared to 38 (8.2%) for the late group (p=0.427). Hernias repaired early were more frequently admitted postoperatively (81.2% vs. 27.2%, p< 0.001). There were no differences in hernia recurrence between early (1.2%) and late (0.8%) hernia repairs (1.2% vs. 0.8%, p=0.359). The median time to recurrence was 3 months [IQR 2.0, 9.0] for early repairs and 9 months [IQR 4.3, 11.5] for late hernia repairs (p=0.218). On multivariable logistic regression, having a comorbid condition (Odds ratio (OR) 2.679 [CI 1.412, 5.082], p=0.003) and inguinal hernia repair performed laparoscopically (OR 2.068 [CI 1.122, 3.811], p=0.020) were associated with a higher risk of recurrence, while early repair was not (OR 1.659 [CI 0.587, 4.688], p=0.340).

Conclusion: Early inguinal hernia repair in preterm infants before 55 weeks postmenstrual age is more common and does not appear to be associated with an increased risk of hernia recurrence compared to delayed repair.