Splanchnic vasoregulation during mesenteric ischemia and reperfusion in pigs

Area of Science:

• Physiology
• Hepatology
• Hemodynamics

Background:

• The hepatic arterial buffer response (HABR) is a critical physiological mechanism regulating liver blood flow.
• Understanding factors affecting HABR is essential for managing hepatic perfusion and function.

Purpose of the Study:

• To evaluate the impact of reduced superior mesenteric arterial blood flow on the hepatic arterial buffer response (HABR) to portal vein (PV) occlusion.
• To assess the recovery of HABR following a period of mesenteric hypoperfusion and subsequent reperfusion.

Main Methods:

• The study involved seven pigs subjected to 2 hours of reduced superior mesenteric arterial blood flow followed by 1 hour of reperfusion.
• Measurements included celiac trunk blood flow (Qtr), hepatic arterial blood flow (Qha), and the response to portal vein (PV) occlusion.
• A control group of seven pigs was used for comparison.

Main Results:

• Reduced mesenteric blood flow led to increased Qtr and Qha during hypoperfusion.
• The HABR was significantly impaired after 120 minutes of reduced mesenteric blood flow, with Qha response to PV occlusion diminishing.
• While HABR showed partial recovery during reperfusion, it remained compromised compared to baseline.

Conclusions:

• Reduced mesenteric perfusion significantly impairs the hepatic arterial buffer response (HABR).
• The HABR demonstrates only partial recovery after reperfusion, indicating potential lasting effects of mesenteric hypoperfusion.
• The study highlights the complex interplay between mesenteric and hepatic blood flow regulation.