Middle Hepatic Vein (MHV)anatomy and its effect on the outcomes in Modified Right Lobe(MRL) grafts in Living donor Liver transplant(LDLT)

Abstract

Introduction: Right lobe is the usual graft of choice in LDLT. The anatomy of the MHV(V5,V8) is an important determinant of the venous outflow of the anterior segment. Modified Right lobe grafts are commonly used grafts which usually require the reconstruction of the MHV. This Neo MHV is also prone to thrombosis which could be early or late in the post operative period. We reviewed the impact of MHV reconstruction and the effect of late MHV thrombosis on outcome after transplantation. Method: All the 287 patients who underwent MRL -LDLT between February 2017 to November 2018 were enrolled in the study.MHV anatomy was classified according to number of Segment 5 (V5) and Segment 8 (V8) vein present in the graft into, MHV type 1 (V5-1,V8-1,n=133 ), type 2 (V5-2,V8-1, n=47), type 3 (V5-1,V8-2, n=51), type 4 (MH2= V5-2,V8-2, n=25 ), type 5A (V5≥3,V8-any number,n=10 ), type 5B (V5-any number, V8≥3,n= 12), type 6 (X5= V5-0, V8- any number,n=4), type 7 (X8=V5-any number,V8-0,n=4 ). Statistical analysis was done using chi-square test for nominal variables and wilcoxon test for continuous variables. Result: There was no difference in any of the patient demographics or pre-op parameters. Cold ischemic time was significantly prolonged in MHV5A type (136.5 ±11.6) and least in Type 7 (75.7 ±18.4) F (7,278) = 4.2,p= 0.0002). All other intraoperative and postoperative parameters were comparable among the groups. MHV thrombosis was seen in 33.1% of all patients and they had a higher morbidity(51.57% vs 19.79%). Postoperatively, the incidence of MHV thrombosis was similar between the groups (p=0.56). Conclusion: None of the MHV types affected the outcome in our cohort. Thus, if proper outflow is given during benching all graft can function well irrespective number of veins. However, late MHV thrombosis has a significant effect on the morbidity and re admission rates.