Should temporary extracorporeal continuous portal diversion replace meso/porta-caval shunts in "small-for-size" syndrome in porcine hepatectomy?

Aim: To investigate the feasibility of temporary extracorporeal continuous porta-caval diversion (ECPD) to relieve portal hyperperfusion in "small-for-size" syndrome following massive hepatectomy in pigs.

Methods: Fourteen pigs underwent 85%-90% liver resection and were then randomly divided into the control group (n = 7) and diversion group (n = 7). In the diversion group, portal venous blood was aspirated through the portal catheter and into a tube connected to a centrifugal pump. After filtration, the blood was returned to the pig through a double-lumen catheter inserted into the internal jugular or subclavian vein. With the conversion pump, portal venous inflow was partially diverted to the inferior vena cava through a catheter inserted via the gastroduodenal vein at 100-130 mL/min. Portal hemodynamics, injury, and regeneration in the liver remnant were compared between the two groups.

Results: Compared to the control group, porta-caval diversion via ECPD significantly mitigated excessive portal venous flow and portal vein pressure (PVP); the portal vein flow (PVF), hepatic artery flow (HAF), and PVP in the two groups were not significantly different at baseline; however, the PVF (431.8 ± 36.6 vs 238.8 ± 29.3, P < 0.01; 210.3 ± 23.4 vs 122.3 ± 20.6, P < 0.01) and PVP (13.8 ± 2.6 vs 8.7 ± 1.4, P < 0.01; 15.6 ± 2.1 vs 10.1 ± 1.3, P < 0.05) in the control group were significantly higher than those in the diversion group, respectively. The HAF in the control group was significantly lower than that in the diversion group at 2 h and 48 h post hepatectomy, and ECPD significantly attenuated injury to the sinusoidal lining and hepatocytes, increased the regeneration index of the liver remnant, and relieved damage that the liver remnant suffered due to endotoxin and bacterial translocation.

Conclusion: ECPD, which can dynamically modulate portal inflow, can reduce injury to the liver remnant and facilitate liver regeneration, and therefore should replace permanent meso/porta-caval shunts in "small-for-size" syndrome.