Increased intestinal permeability: implications for thoracoabdominal aneurysm repair

Area of Science:

• Vascular Surgery
• Gastroenterology
• Coagulation Disorders

Background:

• Coagulopathy and massive bleeding are significant causes of mortality in thoraco-abdominal aneurysm repair.
• Increasing supraceliac aortic cross-clamp time exacerbates disseminated intravascular coagulation due to superior mesenteric artery occlusion and reperfusion.

Purpose of the Study:

• To investigate the mechanism by which superior mesenteric artery reperfusion following aortic clamping induces disseminated intravascular coagulation.
• To assess the impact of varying supraceliac aortic cross-clamp durations on intestinal permeability and related physiological parameters.

Main Methods:

• Twenty dogs were divided into four groups: 30, 60, 90 minutes of aortic cross-clamping, and a control group.
• Intestinal permeability was measured using lactulose/mannitol absorption.
• Venous effluent was analyzed for endotoxin, potassium, bacteria, and pH; urine was collected for six hours.

Main Results:

• Lactulose absorption, indicating increased intestinal permeability, was significantly higher in all experimental groups compared to the control.
• A significant correlation between increased intestinal permeability and longer clamp times (60 and 90 minutes) was observed.
• No significant changes in venous endotoxin, potassium, or bacterial presence were detected; however, the 90-minute group showed a significant decrease in pH.

Conclusions:

• Supraceliac aortic clamping increases intestinal permeability.
• This increased intestinal permeability is time-dependent, becoming significant with clamp durations of 60 minutes or more.
• Maintaining aortic cross-clamp times under one hour may minimize the risk of increased intestinal permeability and associated coagulopathy.