Background. Although living donor liver transplantation for small pediatric
patients is increasingly accepted, its expansion to older/larger patients
is still in question because of the lack of sufficient information on the i
mpact of graft size mismatching.
Methods. A total of 276 cases of living donor liver transplantation, exclud
ing ABO-incompatible, auxiliary, or secondary transplants, were reviewed fr
om graft size matching. Forty-three cases were highly urgent cases receivin
g intensive care preoperatively. Cases were categorized into five groups by
graft-to-recipient weight ratio (GRWR): extra-small-for-size (XS; GRWR<0.8
%, 17 elective and 4 urgent cases), small (S; 0.8 less than or equal to GRW
R<1.0%, 21 and 7), medium (M; 1.0 less than or equal to GRWR<3.0%, 119 and
19), large (L; 3.0 less than or equal to GRWR<5.0%, 67 and 10), and extra-l
arge era; GRWR greater than or equal to 5.0%, 9 and 3).
Results. Smaller-for-size grafts were associated not only with larger and o
lder recipients, but also with rather older donors. Posttransplant bilirubi
n clearance was delayed and aspartate aminotransferase corrected by relativ
e graft size was higher in XS and S. Posttransplant hemorrhage and intestin
al perforation were more frequent in XS and S, and vascular complications a
nd acute rejection were more frequent in larger-for-size grafts. Consequent
ly, graft survival in XS (cumulative 58% and actuarial 42% at 1 year) and S
(76% and 74%) was significantly lower compared with that in M (93% and 92%
) in elective cases. Graft survival in L (83% and 82%) and XL (75% and 71%)
did not reach statistical significance.
Conclusions. The use of small-for-size grafts (less than 1% of recipient bo
dy weight) leads to lower graft survival, probably through enhanced parench
ymal cell injury and reduced metabolic and synthetic capacity. Although lar
ge-for-size grafts are associated with some anatomical and immunological di
sadvantages, the negative impact is less pronounced.