Living-Donor Liver Transplant Tawfik Ayoub and Nicolas Jabbour L iver transplantation has become mainstream sur- gical therapy for patient with end-stage liver disease with an operative mortality of less then 5% and 1- and 5-year survival rates 85% and 65%, respectively. 1-5 The disproportionate increase in patients awaiting liver transplant compared to the number of available organs 6,7 has led to the devel- opment of new techniques, including “living donor liver transplants” (LDLT), “split liver transplants,” and more recently, the reintroduction of “non-beat- ing-heart liver donors.” 8 In the United States, the total number of liver transplants performed as of today is 58,507, of which 2,065 are from live donors and 56,442 are from cadavers, 9 which is a ratio of 1:27 live-donor to cadaveric liver trans- plants. The first successful living-donor liver transplan- tation was performed in 1989, with transplantation of a left hepatic lobe. Because of cultural beliefs discouraging cadaveric transplants in Asia, exten- sive development in the field of living-donor liver transplant was performed in the early 1990s; al- most all liver transplantations performed in Asia involved living donors, whereas in the United States relatively few living-donor liver transplan- tations were performed until recently. It was mainly performed on children and used a left he- patic lobe (or one or more of its segments) from a parental donor. In the United States, adult left- hepatic-lobe transplantation was attempted in the 1990s, but without much success. The smaller left hepatic lobe provides insufficient hepatic mass for most adult Americans, who are physically larger than most Asians and consequently, the outcome of adult-to-adult left-hepatic-lobe transplantation in the United States was poor, and the procedure was seldom performed. 10 The first successful adult right LDLT was reported by Fan et al in 1997; 11 since then, right LDLT is the preferred adult LDLT. ETHICAL ISSUES RELATED TO LDLT A major ethical dilemma related to LDLT is the possible compromise of a healthy person to save the life of an end-stage liver-failure patient. Pa- tients with end-stage liver disease don’t have the option of dialysis available to renal-failure pa- tients, and without a liver transplant the ultimate result is death. Many issues arise related to that procedure, including organ shortage and the avail- ability of a cadaveric liver for the recipient, the chances of the recipients’ survival, and the risk of morbidity and/or mortality in the healthy donor. Currently, the mortality risk to the donor is much lower then 1% and the morbidity risk is about 5%. This compares to a mortality rate of 11% 20 years ago. 12,13 Blood loss associated with the liver donors var- ies according to the surgeon and the center where it is performed, ranging from 615 mL to 998 mL in different studies. 14-16 Efforts to minimize transfu- sion, including blood salvage, acute isovolumic hemodilution, and/or preoperative autologous do- nation should be performed to avoid the risk asso- ciated with heterologous blood transfusions. HEPATIC HOMEOSTATIC CIRCULATION The total hepatic blood flow is 1,200-1,400 mL/ min (100 mL/min/100 g of tissue), which is 25% of the total cardiac output. The hepatic artery sup- plies 25-30% of total hepatic blood flow and ac- counts for 45-50% of oxygen supply. The rest of the blood supply (70-75%) is provided by the portal vein and accounts for 50-55% of the total oxygen supply. From the Department of Anesthesiology, Keck School of Medicine, LAC+USC Medical Center, University of Southern California, Los Angeles, CA. The data and analyses reported in the 2003 Annual Report of the U.S. Organ Procurement and Transplantation Network and the Scientific Registry of Transplant Recipients have been sup- plied by UNOS and URREA under contract with HHS. The authors alone are responsible for reporting and interpreting these data. Address reprint requests to Tawfik Ayoub, MD, Department of Anesthesiology, LAC-USC Medical Center, 1200 N. State Street, Los Angeles, CA 90033. E-mail: tayoub@usc.edu © 2004 Elsevier Inc. All rights reserved. 0277-0326/04/2301-0009$30.00/0 doi:10.1053/j.sane.2003.12.003 62 Seminars in Anesthesia, Perioperative Medicine and Pain, Vol 23, No 1 (March), 2004: pp 62-65