Acquired Diaphragmatic Hernia Following Pediatric Liver Transplantation: Incidence, Risk Factors and Surgical Outcomes

Introduction: Acquired diaphragmatic hernia (ADH) is an uncommon yet relevant complication after pediatric liver transplantation (pLTx). True incidence and risk factors remain poorly defined, largely due to limited screening, heterogeneous imaging practices, and the absence of validated predictive models. This study aimed to determine incidence, presentation, and risk factors for ADH and to compare surgical repair techniques and short-term outcomes of thoracoscopic versus open approaches. Materials and Methods: We performed a retrospective review of all children undergoing pLTx at our institution (2014 and 2024). Demographic and transplant-related data were analyzed in patients with and without ADH. Operative approach, postoperative recovery, and six-month follow-up were assessed. Findings were placed into context by comparison with published series. Main Results: Among 246 pediatric transplant recipients, 8 children developed ADH (3.3%). Two patients had bilateral defects; each side was repaired electively in separate, staged procedures. Counting each side as a distinct repair event yielded 10 ADH repair procedures for analysis. Children who developed ADH were significantly younger at transplantation (mean 9.7 vs. 64.0 months, p = 0.002) and had lower body weight (7.8 vs. 20.7 kg, p = 0.004). Prior abdominal surgery was common (5/8). Seven patients received a left lateral segment graft (LLS); graft-to-recipient weight ratio was 3.8% versus 3.2% in non-ADH patients (p = 0.107). Most hernias were right-sided, with presentations ranging from respiratory symptoms to incidental imaging findings. Surgical repair was performed via laparotomy in six cases and thoracoscopy in four, with one conversion to thoracotomy. Short-term outcomes were favorable in both groups, with only one recurrence (after laparotomy) and no mortality during follow-up. Conclusions: ADH after pLTx occurred in a minority of recipients and was associated with younger age, low body weight, prior abdominal surgery, and LLS grafts. However, the specific contribution of these variables remains unclear. Persistent research gaps include the lack of standardized screening protocols, uncertainty regarding cumulative long-term risk, and the absence of predictive models to identify high-risk patients. Addressing these issues requires multicenter collaboration and prospective surveillance strategies. Thoracoscopic repair was feasible in selected patients and may be considered when suitable.