Extreme size mismatch: bronchus compression by an oversized donor heart in small children

Area of Science:

• Cardiology
• Thoracic Surgery
• Pediatric Transplantation

Background:

• Liberal donor-recipient weight ratio (DRWR) criteria may improve waitlist survival in critically ill patients.
• Size matching in pediatric heart transplantation is a critical factor for successful outcomes.
• Left ventricular assist device complications necessitated an urgent heart transplant for a pediatric patient.

Observation:

• A 2-year-old received an adult donor heart (DRWR 4.4), leading to immediate postoperative graft dysfunction due to thoracic space constraints.
• Computed tomography revealed left bronchial compression and left lung collapse caused by the oversized allograft.
• The patient required extracorporeal membrane oxygenation (ECMO) support for initial recovery.

Findings:

• Graft function improved within one month with ECMO support.
• The transplanted heart demonstrated adaptive size remodeling within six months.
• Concomitant left bronchus re-expansion occurred, resolving the initial respiratory compromise.
• The patient was discharged with minimal respiratory sequelae after a complicated recovery.

Implications:

• This case demonstrates a successful strategy for managing early morbidities associated with oversized heart allografts in pediatric recipients.
• Findings support expanding donor size criteria in pediatric heart transplantation to increase donor pool availability.
• Adaptive remodeling of oversized grafts offers a potential pathway to improved outcomes in size-mismatched pediatric heart transplants.