NEW YORK (Reuters Health) - In a study of living donor liver transplantations with left side grafts, no significant difference in survival was seen when grafts <35% of the recipient's standard liver volume (SLV) were used versus larger grafts. Being able to use smaller grafts can reduce the risks to the donor.
In a previous study, Dr. Shinichi Miyagawa and colleagues from Shinshu University School of Medicine, Matsumoto, Japan, had shown that a recipient's metabolic demands can be met using grafts as low as 30% of the recipient's SLV. In the current study, the team examined the impact of graft size on several clinical outcomes, including survival.
The study, reported in the November issue of Liver Transplantation, featured 120 adult recipients of left side liver grafts (either the left lobe alone, or the left lobe with the caudate lobe). Thirty-three received grafts <35% of their SLV and 87 received larger grafts. The recipient and donor characteristics for the two groups were comparable, except that mean pretransplant prothrombin time and INR were higher and mean body weight was greater in the group that received the relatively smaller grafts.
The average graft volume/recipient SLV ratio was 31.8% in the smaller graft group and 42.5% in the larger graft group, the report indicates.
Pretransplant Model for End-Stage Liver Disease (MELD) scores were similar in the two groups, as were postoperative serum total bilirubin levels, prothrombin time, INR, and hospital stay, the report indicates. Likewise, the 1-year patient and graft survival rates in the smaller and larger graft groups were not significantly different (80.7% vs. 90.8%), nor were the 5-year survival rates (64.2% vs. 84.9%).
The rate of small-for-size graft syndrome, which is defined by various parameters of graft dysfunction, was "very low" and similar for each group.
Seven deaths were logged from 1 to 5 years posttransplantation and the causes included stroke, recurrent liver cancer, uterine cancer, and sepsis. "These deaths," co-author Dr. Toshihiko Ikegami said in a statement, "occurred in patients with good liver function who had resumed their normal lives. The causes of death were not related to insufficient graft size."
Although the study did not include right lobe grafts, based on their own experience and that of others, the authors believe that left side grafts are preferable.
"We feel that left side grafts should be used more frequently in adult-to-adult living donor liver transplantation because of the lower risk to donors in comparison with right lobe grafts."
