Rayhan Jhanji

Background: Normothermic machine perfusion (NMP) is an emerging strategy for pediatric liver transplantation, but pediatric‐specific viability criteria remain undefined. Lactate clearance, extrapolated from adult protocols, is a central marker of allograft function. In our pediatric NMP (pNMP) experience, we observed a novel pattern: initial clearance followed by secondary rise, termed rebound lactic acidosis. Methods: We retrospectively reviewed pediatric liver allografts preserved on the TransMedics Organ Care System at two centers (January 2025 through June 2026). After excluding donors > 35 kg, 18 perfusions (17 transplants) were classified as rebound lactic acidosis (lactate rise > 0.5 mmol/L after initial clearance) or sustained clearance. Rebound cases were characterized by lactate kinetics, perfusion parameters, acid–base status, bile production, histology, and recipient outcomes. Results: Six allografts demonstrated rebound, with onset 1.0–6.6 h into perfusion. All sustained bile production throughout perfusion. Circuit alkalosis temporally correlated with rebound in three cases and improved with gas flow reduction. The first allograft was discarded; the remaining five were transplanted, including one perfused for 35.5 h. Recipients had elevated POD1 transaminases and INR that normalized by POD7; three are discharged home and two remain hospitalized, all with functioning allografts (follow‐up up to 312 days). Conclusions: Rebound lactic acidosis during pNMP may not indicate allograft nonviability and may be ameliorated by modifying circuit perfusion or pH. Lactate kinetics should be interpreted within a multiparametric viability framework incorporating perfusion adequacy, acid–base status, bile production, liver function, and histology. Pediatric‐specific criteria are needed to safely expand the donor pool.

Background: Gestational alloimmune liver disease is the most common cause of acute liver failure in neonates. Treatment includes exchange transfusion and IVIG, though a subset of neonates requires liver transplantation for survival. Methods: We conducted a retrospective study using the Organ Procurement and Transplantation Network database and an institutional case series to characterize waitlist outcomes and patient survival among transplanted patients with gestational alloimmune liver disease. Results: 81 candidates were registered on the liver transplant waitlist with a neonatal hemochromatosis diagnosis code from October 1987 through March 2025. Of these, 36 (44.4%) received a liver transplant. Re‐transplantation was required in 6 (16.7%) patients. Four patients developed graft failure within the first year of transplant, 3 (75%) of which were due to hepatic artery thrombosis. Patient survival was 88.8% at 30 days, 82.7% at 1 year, and 79.5% at 5 years. Of the 45 candidates (55.6%) who did not receive a transplant, 20 (24.7% of all listed) died on the waitlist, 15 (18.5%) experienced improvement and ultimately did not need transplant, 8 (9.9%) were too sick to transplant, 1 (1.2%) was removed for other reasons, and 1 (1.2%) was transferred to another center. Among the institutional case series, three neonates presented with acute liver failure with workup consistent with GALD. All three were listed as status 1A, underwent successful liver transplant, and are alive present day. Conclusions: Liver transplant should be offered without hesitation for treatment‐refractory GALD. Early referral to a transplant center should occur simultaneously with initiation of medical therapy.