Alternatives to left lateral sector in paediatric liver transplantation—a systematic review on monosegmental and reduced grafts

BACKGROUND: Paediatric liver transplantation (pLT) is the treatment of choice for many liver conditions. However, it still poses relevant challenges, mainly related to the size of the recipients. Unlike in adults, excessive graft volume might represent an issue when the estimated graft-recipient-weight-ratio (GRWR) is significantly disproportionate. In this situation, the traditional left lateral sector (LLS) grafts are too big and other alternatives are required, such as monosegmental or reduced (including hyper-reduced) grafts (RLLS/HRLLS). Results with conventional LLS-pLT are excellent and replicating them with monosegmental or RLLS is challenging given (I) the technical complexity and (II) the need to overcome the large-for-size scenario. This article is to review the existing experience with monosegmental, RLLS/HRLLS grafts and appraise its results. METHODS: Systematic search of the electronic databases, conducted from their inception until May 2020. RESULTS: After scrutiny of the available literature, 16 studies were included reporting 330 patients transplanted with monosegmental and RLLS/HRLLS grafts. There were 10 re-grafts (6 of them <90 days); 90% of grafts were LDLT. Overall, median recipient’s age and weight were 7 months (range, 5 days–22 months) and 5.8 kg (range, 2.6–8 kg) respectively. Median graft weight was 209 grams (range, 124–264 grams) and median GRWR was 3.5% (range, 2.7–5.6%). Hepatic artery and portal vein thrombosis overall incidence were 1.5% and 4.2%; 120 out of the 330 pLT were monosegmental (37%) producing a smaller graft (median of 164 grams) and accordingly a lower GRWR (median 3.2%) compared to reduced LLS. With a median follow-up of 39 months (range, 6–87 months), the overall graft and patient survival were 84% (285/340) and 89% (295/330). DISCUSSION: Monosegmental and RLLS/HRLLS grafts provide access to liver transplantation for very small recipients with excellent results comparable to the standard LLS.