Published online Sep 28, 2019. doi: 10.3748/wjg.v25.i36.5559
Peer-review started: May 15, 2019
First decision: June 16, 2019
Revised: June 27, 2019
Accepted: August 7, 2019
Article in press: August 7, 2019
Published online: September 28, 2019
Left side donor hepatectomy has become more popular given the paramount importance of donor safety. There is limited understanding concerning the medium-term and long-term effect of small-for-size grafts (SFSGs), which is commonly encountered in living donor liver transplantation (LDLT). This study aims to provide more evidence concerning this issue.
The objective is to see if SFSG imposes a negative effect on graft survival. This will help future decision making on performing left donor hepatectomy.
The research objective is to answer whether SFSG is associated with an inferior graft survival through meta-analysis.
Literature comparing the survival outcomes between SFSGs and normal-for-size grafts were limited. In addition, most studies were of small sample size. Meta-analysis allows pooling of the results from these studies. This is the first meta-analysis performed on this important topic.
After extensive literature review following the preset search protocol, there were seven studies comprising of over 1800 LDLT recipients eligible to be included for meta-analysis. It was demonstrated that SFSG is associated with inferior medium-term (3-year) graft survival, but no significant effect on long-term (5-year) graft survival. This result would support the use of SFSG and potentially help promoting left shifting. However, it is beyond the capacity of this study to define what is the smallest graft size that is safe for LDLT.
This is the first study trying to illustrate the effect of SFSG on graft survival using meta-analysis. With the results in this study, SFSG is associated with inferior medium-term but not long-term graft survival. Therefore, for patients who receive a SFSG, graft function should be followed more vigilantly by means of biochemical and radiological investigations. However, SFSG should not be considered an “inferior graft” when compared to normal-for-size grafts judging from the comparable long-term outcome.
The result from this study seems to suggest that left lobe donor hepatectomy should be considered even if it is a SFSG to the transplant recipient for the benefit of better donor safety margin. Due to the heterogeneity of the patients in this study, whether this statement is valid in all liver transplantation indications (i.e., hepatocellular carcinoma) remains to be answered. In addition, the smallest graft size that is safe for LDLT is yet to be defined.