Blood flow reconstruction in portal vein anatomical variations in right lobe living donor liver transplantation

Background. Adequate restoration of blood flow through the portal vein in the graft is only possible with a clear understanding of its anatomy in the donor.The aim was to describe new and extend current data on the portal vein anatomy in a donor of the right liver lobe, to describe variants and formulate principles of portal reconstruction in right lobe living donor liver transplantation.Material and methods. 306 living donor liver transplantations were performed from 2009 to 2021 in the State Research Center – Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency. The vascular anatomy of 518 potential donors was analyzed. Portal vein variants of the anatomy of right lobe graft were assessed.Results. Nine types and 3 subtypes of portal vein branching were evaluated. A, B, C, D, E types match the types described earlier in Nakamura classification. Subtypes B1, B2 и D1 are specifications of types B and D. Types F, G, H, I have been described additionally. The incidence of types and subtypes where reconstruction was made: type A (82%), B (4.6%), B1 (3.9%), B2 (1.3%), C (3.9%), D (3.9%). The incidence of E, G, H, I types among 518 potential donors was 0.4%, 0.6%, 0.2%, 0.4%, respectively. The recipient portal vein complications were detected in 12 cases (3.9%), where 3(25%) were Class 3b according to Clavien-Dindo and 9(75%) of Clavien-Dindo Class 2. There were no correlations between portal vein complications and the method of portal vein reconstruction. (p<0.05). No complications occurred with portal vein in donors.Conclusion. The existing classification of right liver graft portal vein has been updated and detailed. A certain way of reconstruction has been proposed for each portal vein type. Anatomical types in which donation and transplantation are contraindicated have been specified.