Hemodynamics and metabolic effects of prolonged and isolated hepatic artery occlusion in dogs

Background

To improve resectability of several hepatobiliopancreatic tumors, the vascular structures with cancer invasion could be resected and reconstructed. The liver is submitted to a global hypoxia during the hepatic artery reconstruction, since almost 50% of oxygen delivery to this organ is maintained through this vessel. This study addresses the initial impact of prolonged hepatic artery occlusion on liver hemodynamics and oxygen metabolism.

Methods

Seven pentobarbital anesthetized mongrel dogs (19.7 ± 1.2 kg) underwent laparotomy. The gastroduodenal artery was ligated and the common hepatic artery was occluded during 60 min, followed by 120 min of reperfusion. Systemic hemodynamics were evaluated through a Swan–Ganz catheter and arterial catheters. Splanchnic perfusion was assessed by portal vein blood flow (ultrasonic flowprobe), hepatic artery blood flow and liver enzymes (ALT, AST, DHL). Systemic and hepatic oxygen delivery (DO₂s and DO₂h, respectively) were calculated using standard formulae.

Results

The results are presented in Table 1.

Table 1

Conclusion

We conclude that temporary hepatic artery occlusion induces a progressive decrease in portal vein blood flow during ischemia, which is maintained during reperfusion. The hepatic artery blood flow was promptly restored after arterial unclamping. This effect was associated with a significant and progressive reduction in hepatic oxygen delivery that could contribute to the development of postoperative hepatic failure in critically ill patients with a borderline of established preoperative hepatic dysfunction.