Living-donor liver transplantation (LDLT) using a left lobe (LL) graft was first successfully performed in adults in 1993.1 Adult-to-adult LDLT and the use of LL grafts (S2-3-4 ± 1) was associated with a high incidence of small-for-size syndrome (SFSS). This led to the development of new strategies, such as increasing the size of the LL by adding the caudate lobe and the middle hepatic vein (MHV), the application of graft inflow modulation (GIM) techniques to reduce the portal venous flow and pressure in the small graft, the use of right lobe grafts instead of left, and using a dual graft from 2 donors.
The use of the right graft increased the number of adult LDLTs. However, higher donor morbidity and mortality and the severity of complications related to right liver donations2 prompted the reconsideration of LL LDLT.
The hepatic functional mass necessary to reduce the risk of SFSS should optimally encompass a ratio between graft volume and recipient weight (GV/RW) ≥0.8%3 or should reach a ratio between graft volume and standard hepatic volume (GV/SV) of ≥40%.4
A recipient´s portal pressure <15 mm Hg is a second key factor for successful adult LDLT using small grafts, reaching GW/RW between 0.6% and 0.7% or a GV/SV of 35% to 40%.5,6 Thus, when both left and right hepatectomy can provide a GW/RW >0.6% to 0.7%, we believe a left graft should be preferred7 (Fig. 64-1). However, graft selection is carried out on a case-by-case basis with consideration of other risk factors for severe SFSS, such as donor age ≥48 years and Model for End-Stage Liver Disease (MELD) score ≥19.8
Graft selection: flow chart. GV/RW ratio, graft volume/recipient weight ratio; GV/SV %, graft volume/hepatic standard volume percentage; LDLT, living donor liver transplantation.
Variations in hepatic arterial anatomy are encountered in nearly 45% of cases9 (Fig. 64-2). Identification of cases with 2 left arteries is important, as double arterial anastomoses may be necessary. Reconstructing only 1 of 2 hepatic arteries may result in a greater incidence of anastomotic biliary stricture.9 Thus, in these cases we prefer to perform double anastomoses whenever possible.
Hepatic artery in a left living donor. The black line indicates the section point. The graft in A and B will have 1 artery, whereas in C and D it will have 2 arteries. (A) Around 55% of the cases. (B) About 12% of the cases. (C) Around 30% of the cases. (D) about 8%. LL, left liver; RL, right liver.
The most common portal vein (PV) ...