Abstracts
1998 Digestive Disease Week

#1040

APPLICATION OF LIVING-RELATED AND SPLIT-LIVER TRANSPLANTA-TION TO ADULTS: AN ANATOMIC STUDY. P.R. Reichert, J.F. Renz, R.C. Lim, J.P. Roberts, and N.L. Ascher, University of California, San Francisco, CA.

Extension of living-donor (LRLT) and split-liver (SLT) transplantation techniques to adults is limited by graft size. LRLT in adults utilizing an extended right lobe graft (Couinaud segments IV-VIII) has been demonstrated with significant morbidity in donors and recipients (Annals of Surgery 226: 3; 261-270). This study evaluates utilization of an extended left lateral graft (Couinaud segment II / III / IV) in adult LRLT and SLT. Potential graft size and vascular anatomy of a Couinaud II / III / IV graft was determined in 23 liver autopsy specimens and 75 liver acrylic casts. Segment II / III/ IV graft volumes in 23 autopsy specimens ranged from 19 to 45% of total liver volume (TLV) with a mean ± S.D. of 29 ± 6% and median of 29%. Previous data from our group and others have demonstrated the minimal transplanted hepatic mass necessary for survival to range from 20 to 25% of TLV. Twenty grafts (87%) were _ 25% of TLV and 9 grafts (39%) _ 30% of TLV. Hepatic artery and portal venous anatomy permitted extrahepatic division along a plane separating segment IV from V / VIII in each autopsy specimen and cast. Hepatic venous anatomy with respect to creation of a II / III / IV graft are significant in preservation of hepatic mass post-transplantation by ensuring adequate vascular outflow and preventing hepatic congestion. Evaluation of 75 liver acrylic casts revealed a 90% incidence of left and middle hepatic veins forming a "functional unit" in the supply of segments II / III / IV. Segment IV vascular outflow was principally from the left hepatic vein in 7 casts (9%), from the middle hepatic vein in 41 casts (55%), and a dual distribution from left (posteriorly) and middle hepatic veins (anteriorly) in 27 casts (36%). Furthermore, an accessory right hepatic vein _ 5mm in diameter emptied into the inferior vena cava in 40 casts (54%) necessitating caval dissection in the procurement of an extended right lobe graft. We propose LRLT and SLT performed along a plane which includes the left and middle hepatic veins with segments II / III / IV provides adequate graft volume for larger children and adults (approximately 1:1 donor:recipient weight ratio) and offers distinct advantages over procurement of an extended right graft including: preservation of left and middle hepatic veins as a "functional unit" to maximize post-transplantation graft viability, an anatomically less difficult procedure performed extrahepatically with less hilar dissection, no potential caval dissection, and utilization of the left biliary system exclusively of which the anatomy and anatomical variants have been further defined.

Copyright 1996 - 1998, SSAT, Inc. Revised 29 June 1998.