Diaphragmatic hernia after pediatric liver transplantation: graft-specific incidence, clinical characteristics, and outcomes

Background – Diaphragmatic hernia (DH) is a rare but clinically important complication following pediatric liver transplantation. Methods – This retrospective single-center study evaluated consecutive pediatric liver transplant episodes. Clinical characteristics, timing, management, and outcomes of DH were assessed. Transplant episodes with and without subsequent DH were compared. The cumulative incidence of DH was estimated using a competing-risk approach, with death before DH diagnosis treated as a competing event. Results – Diaphragmatic hernia occurred in 16 of 112 pediatric liver transplant episodes (14.3%). All cases occurred following left lateral segment (LLS) transplantation, corresponding to an incidence of 25.0% (16/64) among LLS transplant episodes, whereas no cases occurred after other graft types. Recipients who developed DH were younger at transplantation and had higher graft-to-recipient weight ratio (GRWR) values than those without DH. Approximately half of DH cases were diagnosed within the first 3 postoperative months, and most within the first year. In competing-risk analysis, the cumulative incidence of DH was 7.2% at 3 months, 10.0% at 6 months, and 11.9% at 12 months. Respiratory distress was the most common presentation. All patients underwent surgical repair, and dual mesh reinforcement was used in most cases. Severe postoperative complications were frequent, recurrence occurred in two patients, and no deaths were directly attributable to DH. Conclusion – Diaphragmatic hernia is an unexpected and serious complication following pediatric liver transplantation. In our cohort, DH occurred exclusively after LLS transplantation, and affected recipients were younger and had higher GRWR values than those without DH; however, these characteristics are closely interrelated and their independent contributions could not be determined. Most cases were diagnosed early after transplantation, emphasizing the importance of clinical vigilance, timely diagnosis, and prompt surgical management.