Classification of Left Hepatic Vein Anatomy and Customised Outflow Reconstruction Techniques for Left Lateral Segment Grafts in Paediatric Liver Transplantation

Abstract

Introduction: Anatomical variations of left hepatic vein (LHV) are commonly encountered in paediatric liver transplantation. Meticulous reconstruction is required to prevent hepatic venous outflow obstruction (HVOO). We share our experience of classifying LHV anatomy and customising outflow reconstruction in left lateral segment (LLS) grafts with complex anatomy. Methods: We retrospectively studied 296 paediatric LLS transplants done over a 10 year period. Donor Computed Tomographic images of segment 2 (V2) and 3 (V3) venous drainage, reconstruction techniques used in grafts obtained and surgical outcomes were thoroughly analysed. Results: Three unique variations of LHV were described as in table below and ROC curve analysis (AUC 0.98, p 0.0001) was done to subdivide type 1 LHV. The venous outflow in the LLS graft was classified as graft A with single orifice and graft B with 2 orifices. LHV types 1b, 2 and 3 gave rise to graft B necessitating customised reconstruction techniques as described in table below. We formulated a bespoke algorithm for selecting appropriate reconstruction techniques depending upon donor LHV anatomy (picture). On follow up for a minimum of 1 year, none of the patients developed early or late HVOO. The incidence of early graft dysfunction (p 0.64), acute cellular rejection (p 0.93), intractable ascites (p 0.97), major complications with Clavien-Dindo score ≥3b (p 0.35) and overall survival (p 0.62) were similar between graft A and graft B. Conclusion: Identifying anatomical variations of LHV and tailoring outflow reconstruction, helps to increase the donor pool without compromising surgical outcomes.Tabled 1Type Of LHVn (%)Reconstruction doneType 1a: V2 and V3 join to form a common trunk of length >9mm which joins middle hepatic vein (MHV)Type 1b: V2 and V3 join to form a common trunk of length <9mm which joins middle hepatic vein (MHV)254 (85.8%)16 (5.4%)NoneSimple / extension venoplasty (10), Conjoint Unification venoplasty (6)Type 2: V2 and V3 open separately into IVC6 (2%)Simple / extension venoplasty (2), Conjoint Unification venoplasty (4)Type 3: V2 joins IVC, V3 joins MHV20 (6.8%)Simple / extension venoplasty (2), Conjoint Unification venoplasty (12), Extension unification venoplasty (3), Extension with separate caval anastomosis (3) Open table in a new tab