Effect of left atrial to left femoral artery bypass and renin-angiotensin system blockade on renal blood flow and function during and after thoracic aortic occlusion.

Temporary thoracic aortic occlusion can result in renal insufficiency with or without adjuncts to avoid distal hypoperfusion. In a canine model of thoracic aortic occlusion, left atrial to left femoral bypass was compared with blockade of the renin-angiotensin system. Renin-angiotensin system blockade with the converting enzyme inhibitor, MK422, resulted in restoration of baseline renal blood flow and glomerular filtration 30 minutes after cross-clamp release. Left atrial to left femoral bypass resulted in significant reduction in both renal blood flow and glomerular filtration 30 minutes after cross-clamp release. Stimulation of the renin-angiotensin system plays a significant role in the altered renal hemodynamics and glomerular filtration rates after thoracic aortic occlusion.