Surgical techniques in living liver donors

The essence of living donor operations can be summarized by an uncompromising emphasis on donor safety in conjunction with the procurement of a viable graft for the recipient. In the adult liver transplant recipient, two major issues determine the balance between donor safety and optimal recipient utility. First, the recipient must receive sufficient liver volume, determined by the mass of viable hepatocytes. It is the hepatocellular requirement in the average-sized Western recipient that has created the necessity for right lobe grafts because neither the left lateral segment nor left lobe grafts appeared to be sufficient in most Western adult recipients. This is in contrast to the vast experience in the Orient, where, as a result of a lack of brain death laws, living donors have been the only source of organs for potential transplant recipients. The great amount of Oriental experience, primarily from Japan, demonstrated that the left lobe sufficed in most cases. Second, the vascular and biliary structures required to supply and drain the appropriate liver segments, which, by nature of their variant anatomy, have received the most attention. Clearly, when the parenchymal division occurs in the middle fissure between the left and right lobes (Cantile's line), the confluence of the hilar structures is at greater risk. In addition, because the middle hepatic vein straddles the major fissure, variably draining the anterior segments of the right lobe as well as the medial segment of the left lobe, it creates certain technical problems related to venous drainage not typically encountered in left segmental hepatectomy. Furthermore, the presence of accessory hepatic veins of the right has created the necessity for multiple hepatic venous anastomoses in the recipient to ensure appropriate venous drainage of the graft. Finally, the consistently variable biliary drainage of the right lobe has resulted in biliary complications in both the donor and recipient and continues to plague the right lobe graft as the "Achilles heel" of this operation, albeit decreasing in frequency with increasing experience. It is becoming clear that the left lateral segment graft should be used almost exclusively for pediatric recipients. The left lobe appears to play a role in either adolescent recipients, or small adult recipients, whereas the right lobe has become the graft of choice for average to full-sized adult recipients. The experience with right lobe grafts remains meager compared with either the left lobe or the left lateral grafts. However, many lessons have been learned from the initial experience, which has resulted in the contemplation of technical modifications of the original descriptions. In this article, we endeavor to review the standard donor procedure for right and left lobes and to highlight any relevant contributions to the recent literature. Because the focus of this article is the adult recipient, we limit our review to right and left lobe donor hepatectomy and omit any detailed discussion on left lateral segmentectomy.