Three-dimensional CT volumetry is useful for size matching in cases of living-related orthotopic liver transplantation.

ObjectiveTo evaluate the impact of graft size on recipients in living donor liver transplantation (LDLT) to establish a clinical guideline for the minimum requirement. Summary Background DataAlthough the minimum graft size required for LDLT has been reported to be 30% to 40% of graft volume (GV)/standard liver volume (SLV), the safety limit of the graft size was unknown. MethodsA total of 33 cases of LDLT, excluding auxiliary transplantation, were reviewed with a minimum observation period of 4 months. The 33 patients were divided into three groups according to GV/SLV: medium-size graft group, small-size graft group, and extra-small graft group. The effect of GV/SLV on graft function, graft regeneration, and survival was evaluated. ResultsThe overall patient survival rate was 94% at a mean follow-up of 15 months with a minimum observation period of 4 months. There were no statistically significant differences in postoperative bilirubin clearance, alanine aminotransferase, prothrombin time, and frequency of postoperative complications among the three groups. One week after transplantation, the regeneration rate (GV at 1 week/harvested GV) in the extra-small and small groups was significantly higher than that of the medium group. The graft and patient survival rates were both 100% in the extra-small group, 75% and 88% in the small group, and 90% and 95% in the medium group. ConclusionsSmall-for-size grafts less than 30% of SLV can be used with careful intraoperative and postoperative management until the grafts regenerate.Since the first success in 1989, 1 living donor liver transplantation (LDLT) has been refined and accepted as a valuable treatment for patients with terminal liver disease. 2Although LDLT was originally developed as a response to the shortage of pediatric donors, this procedure has recently been extended to adult patients in countries where the availability of cadaveric donors is severely restricted.3 Accompanying these trends, there has been a move toward increasing the size of harvested grafts, from an extended lateral segment to an extended left lobe, and to right lobe grafts. 4 However, donor safety in LDLT must remain a prerequisite. The major concern in using LDLT for adult patients is the adequacy of the size of the graft that can be safely harvested from the donor. The Shinshu University group accepted a donor-recipient combination that gives an estimated graft volume (GV)/standard liver volume (SLV) ratio of more than 30%.3 Lo et al 5 reported that a graft with GV/SLV of 40% or less should be regarded as a marginal graft that would have a lower success rate. However, experience with adult-to-adult LDLT is limited, and the minimum graft size remains unknown. In the current study, we investigated whether a small GV/SLV ratio was correlated with a poorer outcome in LDLT.

Graft size problems remain the greatest limiting factor for expansion of living donor liver transplantation (LDLT) to the adult population. The result of adult-to-adult LDLT using the left lobe with special reference to graft size has not been fully evaluated to date. In this study, we evaluated the outcome of adult-to-adult LDLT using the left lobe and also analyze the impact of using small-for-size grafts on outcome. Thirty-six recipients who underwent adult-to-adult LDLT using the left lobe (n ‫؍‬ 14) or left lobe plus caudate lobe (n ‫؍‬ 22) were included in the study. Variables including preoperative and operative data, patient and graft survival, complications, and causes of graft loss were studied. Furthermore, the incidence of small-for-size syndrome and its impact on graft survival were studied. Mean graft volume (GV) was 420 ؎ 85 g (range, 260 to 620 g), which resulted in 38.2% ؎ 8.1% (range, 22.8% to 53.8%) of the recipient standard liver volume (SLV). Overall 1-year patient and graft survival rates were 85.7% and 82.9%, respectively. Seven grafts were lost. Small-for-size syndrome occurred in 7 of 16 patients (43.8%) with cirrhosis and only 1 of 20 patients (5.0%) without cirrhosis (P ‫؍‬ .005). Recipients who developed small-for-size syndrome had inferior graft survival to those who did not (P ‫؍‬ .07). In conclusion, adult-to-adult LDLTs were found to be feasible without affecting patient or graft survival. Small-for-size syndrome developed more frequently in patients with cirrhosis. Minimum GV in adult-to-adult LDLT should be 30% less than the recipient's SLV in patients without cirrhosis, whereas 45% less was required in patients with cirrhosis. (Liver Transpl 2003;9:581-586.)

In conclusion, the use of a fatty liver graft up to the moderate level can be justified in LDLT, even though ischemia-reperfusion injury tends to be severe in such grafts.