Critical graft size and functional recovery in living donor liver transplantation

With a high prevalence of chronic hepatitis B and a low cadaveric organ donation rate, living donor liver transplantation (LDLT) remains the only option for many patients in Hong Kong. In such cases, the liver graft volume is smaller owing to a partial liver graft; therefore, a problem of small-for-size grafts often occurs. Between September 1999 and April 2003, 25 cadaveric, 16 living related, and 1 auto-LTs were performed at our center. The outcomes of LDLT were analyzed to assess the critical graft size and functional recovery. Among the 16 LDLT recipients (mean age, 44.4 +/- 14.4 years; mean weight, 61.9 +/- 11.4 kg), 1 patient received a graft from a donor left lobe (weight, 400 g) in an auxillary partial orthotopic LT (APOLT), 12 received right lobes, and 3 received left lobes. Besides the APOLT case, the overall graft/recipient weight ratio (GRWR) for the 15 LDLTs was 1.11 (0.76 to 1.75). The GRWR in the 25 cadaveric LTs was 1.92 (1.05 to 3.69) (P < .001). Among the 12 successful LDLTs, there were 5 (41.7%) cases of small-for-size graft syndrome: 3 of 3 (100%) in GRWR < or = 0.8%; 5 of 6 (83.3%) in GRWR < 1%; and 0 of 6 with GRWR > 1%. The initial post-LT graft function parameters were significantly higher among the LDLT group: International normalized ratio (INR), 1.42 vs 1.24, P = .03; alanine aminotransferase (ALT, 387 vs 201 IU/L, P = .005, and bilirubin, 170 vs 48 micromol/L, P < .001 as compared to the cadaveric transplant group). Small-for-size graft syndrome can be avoided if GRWR > 1%, but often occurs when GRWR < 0.8%. Graft function in LDLT recovers more slowly than in cadaveric liver transplant.