Endocrine Effects of Simulated Complete and Partial Aortic Occlusion in a Swine Model of Hemorrhagic Shock

• Published in: Military medicine Vol. 184; no. 5-6; pp. e298 - e302
• Main Authors: Hoareau, Guillaume L, Williams, Timothy K, Davidson, Anders J, Russo, Rachel M, Ferencz, Sarah-Ashley E, Neff, Lucas P, Grayson, J Kevin, Stewart, Ian J, Johnson, M Austin
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-05-2019
• Subjects: Aldosterone - analysis; Aldosterone - blood; Angiotensin II - analysis; Angiotensin II - blood; Animals; Aorta - enzymology; Aorta - surgery; Balloon Occlusion - adverse effects; Balloon Occlusion - methods; Coronary vessels; Disease Models, Animal; Endocrine System - blood supply; Endocrine System - enzymology; Hemorrhagic shock; Hydrocortisone - analysis; Hydrocortisone - blood; Renin - analysis; Renin - blood; Statistics, Nonparametric; Swine; angiotensin; cortisol; REBOA; renin; aldosterone
• ISSN: 0026-4075; 1930-613X
• DOI: 10.1093/milmed/usy287

Abstract
Introduction
Low distal aortic flow via partial aortic occlusion (AO) may mitigate ischemia induced by resuscitative endovascular balloon occlusion of the aorta (REBOA). We compared endocrine effects of a novel simulated partial AO strategy, endovascular variable aortic control (EVAC), with simulated REBOA in a swine model.
Materials and methods
Aortic flow in 20 swine was routed from the supraceliac aorta through an automated extracorporeal circuit. Following liver injury-induced hemorrhagic shock, animals were randomized to control (unregulated distal flow), simulated REBOA (no flow, complete AO), or simulated EVAC (distal flow of 100–300 mL/min after 20 minutes of complete AO). After 90 minutes, damage control surgery, resuscitation, and full flow restoration ensued. Critical care was continued for 4.5 hours or until death.
Results
Serum angiotensin II concentration was higher in the simulated EVAC (4,769 ± 624 pg/mL) than the simulated REBOA group (2649 ± 429) (p = 0.01) at 180 minutes. There was no detectable difference in serum renin [simulated REBOA: 231.3 (227.9−261.4) pg/mL; simulated EVAC: 294.1 (231.2−390.7) pg/mL; p = 0.27], aldosterone [simulated EVAC: 629 (454−1098), simulated REBOA: 777 (575−1079) pg/mL, p = 0.53], or cortisol (simulated EVAC: 141 ± 12, simulated REBOA: 127 ± 9 ng/mL, p = 0.34) concentrations between groups.
Conclusions
Simulated EVAC was associated with higher serum angiotensin II, which may have contributed to previously reported cardiovascular benefits. Future studies should evaluate the renal effects of EVAC and the concomitant therapeutic use of angiotensin II.