Published online Aug 21, 2013. doi: 10.3748/wjg.v19.i31.5076
Revised: June 28, 2013
Accepted: July 9, 2013
Published online: August 21, 2013
AIM: To investigate the capacity of shunts to relieve portal hypertension and decrease the safe minimal liver remnant in pigs.
METHODS: A subtotal hepatectomy with < 60 mL blood loss and without hepatic pedicle occlusion was performed. The mesenteric venous inflow was diverted through a mesocaval shunt (MCS) constructed using the prepared left renal vein with an end-to-side running suture of 5-0 proline. All 21 animals that underwent subtotal hepatectomy and/or MCS were divided into three groups. In the 15% group, the residual volume was 14%-19% of total liver volume (TLV); in the 15%+ S group, the residual volume was also 14%-19% of TLV with a mesocaval shunt (MCS); and in the 10%+ S group, the residual volume was 8%-13% of TLV with an MCS. In the three groups, the intraoperative portal vein pressure (PVP) and portal vein flow (PVF) were monitored and compared at laparotomy and 1 h post-hepatectomy. The survival rate, sinusoidal endothelial damage, tissue analysis, and serum analysis were investigated among the three groups.
RESULTS: The percentage residual liver volume was 15.9%, 16.1% and 11.8% in the 15%, 15%+ S, 10%+ S groups, respectively. After hepatectomy, PVF and portal-to-arterial flow ratio in the 15%+ S group significantly decreased and hepatic artery flow (HAF) per unit volume significantly increased, compared to those in the 15% group. The PVP in the 15%+ S group and 10%+ S group increased slightly from that measured at laparotomy; however, in the 15% group, the PVP increased immediately and significantly above that observed in the other two groups. The 14-d survival rates were 28.5%, 85.6%, and 14.2% in the 15%, 15%+ S, and 10%+ S groups, respectively. In the 15%+ S group, the shunts effectively attenuated injury to the sinusoidal endothelium, and the changes in the serum and tissue analysis results were significantly reduced compared to those in the 15% and 10%+ S groups.
CONCLUSION: MCS can decompress the portal vein and so attenuate liver injury from hyperperfusion, and make extreme or marginal hepatectomy safer.
Core tip: When the residual liver volume is extremely small after extended hepatectomy or living-donor liver transplantation, postoperative hepatic failure (PHF) or small-for-size syndrome (SFSS) may result from portal hypertension or hyperperfusion. We demonstrated that mesocaval shunt attenuated portal overflow injury, however, it is unknown how much the shunt can decrease, and whether the shunt can do the same for small liver remnants following subtotal hepatectomy. We showed that the residual volume was the determinant factor of PHF or SFSS after subtotal hepatectomy, and the shunt attenuated injury from hyperperfusion, and made marginal hepatectomy safer.