Whole pediatric liver graft in modified RAPID transplantation for unresectable colorectal liver metastases.

Liver transplantation has re-emerged as a therapeutic option for unresectable colorectal liver metastases (CRLM), but organ shortage and allocation concerns remain major limitations. The RAPID procedure combines auxiliary liver transplantation with delayed total hepatectomy, allowing small-graft use while the native liver provides temporary metabolic support. We report a modified RAPID transplantation, interpreted as a RAPID-derived staged auxiliary orthotopic liver transplantation (AOLT) strategy, using a whole pediatric graft in a 68-year-old woman with liver-only CRLM and sustained response to chemotherapy. The graft, from a 2-year-old donor (280 g; GRWR 0.4), had been declined by all pediatric centers due to non-standard infectious risk and was authorized by the Italian National Transplant Center within a regulated pathway. Favorable arterial anatomy preserved native right liver perfusion, while portal inflow management combined intentional surgical narrowing of the right portal vein with delayed portal vein embolization (PVE). At pre-PVE CT, graft volume was 350 cc (estimated GRWR 0.5); after PVE, it reached 580 cc (estimated GRWR 0.8), enabling completion hepatectomy at four weeks. At eight months, the patient had normal liver function and no recurrence. To our knowledge, this is the first reported use of a whole pediatric liver graft in modified RAPID transplantation.