Graft size-matching in living related partial liver transplantation in relation to tissue oxygenation and metabolic capacity

Abstract

The influence of graft size-matching on tissue oxygenation and metabolic capability was studied in living related partial liver transplantations for 47 pediatric patients. Their age ranged from 4 months to 17 years 3 months, their body weight from 4.0 to 58.0 kg, graft weight from 191 to 440 g, and graft weight/recipient body weight ratio from 0.61% to 6.0%. Tissue oxygenation and its heterogeneity were investigated by measuring oxygen saturation of hemoglobin in the liver sinusoid (SO2), coefficient of variation of SO2, and arterial ketone body ratio. The metabolic capacity of the graft was investigated by measuring bilirubin clearance, recovery of cholesterol esterification, and ketone body production. In infants with a relatively large liver graft, both intra- and extracellular oxygenation remained low soon after reperfusion but recovered to the control value by the end of the operation. In adolescent recipients of a relatively small graft, by contrast, synthetic and detoxification capacities were relatively deficient; however, these improved with time. These results indicate that sufficient tissue oxygenation and liver regeneration are essential for successful liver transplantation with relatively large and small grafts, respectively.

Size mismatch in liver transplantation

“…Consequent to aforementioned physiologic disturbances between the donor and the recipient, metabolic mismatch may contribute to the development of small‐for‐size syndrome. Tanaka et al showed that there is a correlation between graft/recipient size mismatch and bilirubin clearance in post‐transplant day 1. Cholesterol esterification was suppressed compared to preoperative level for 2 weeks in small‐for‐size grafts presumably due to delayed synthesis of acetyltransferase and Apoprotein A1, indicating that graft synthetic function was delayed in small‐for‐size grafts.…”

“…A large graft receives relatively low portal blood flow due to relatively small recipient body size, which impairs hepatic microcirculation . Rangel Moreira Dde et al showed that using a porcine model significantly lowers portal venous flow with a higher level of lactic acid and arteriovenous pCO 2 difference with lower pH, which represents the lower tissue perfusion, in the large‐for‐size group.…”

Living donor liver transplantation

“…It must be accurate, as much as possible, in order to not only guarantee enough graft volume to the recipient but mainly to assure enough residual liver volume to the donor. In general, a graft volume body weight ratio (GVBWR) of 0.8 [43] or 40% of the recipient's standard liver volume [32,44] is recommended as a minimum cut‐off for the recipient, even though successful transplantations have been reported with GVBWR <0.7 [45,46]. The Kyoto group showed a statistically significant correlation between complication, graft loss, and a GVBWR of <0.8 [47].…”

The outcome of primary liver transplantation from deceased donors in children with body weight ≤10 kg

“…After closure of the abdomen the large for size grafts are prone to compression, which can cause partial liver necrosis or compromise the flow in afferent hepatic vessels and result in thrombosis (40). Two studies from Japan showed that graft oxygenation was lower intraoperatively in oversized grafts and these grafts likely suffered dysoxia (41, 42). Other problems that can arise from too tight abdominal closure because of oversized graft include renal failure and respiratory failure.…”