Mesenteric Blood Flow During Cardiopulmonary Bypass In Pigs

Background: Gastrointestinal complications represent a serious problem after cardiopulmonary bypass. Hypoperfusion of the gastrointestinal tract during bypass has been implicated as the cause. We therefore investigated blood flow in the superior mesenteric artery during cardiopulmonary bypass. Methods: Mature female pigs (n = 12) were investigated. While six sham-operated animals served as control (group I), six pigs underwent normothermic cardiopulmonary bypass for 180 minutes (group II). Bypass flow was 2.4 l/m²/minute. Standard regimens for anesthesia and cardiopulmonary bypass were used. Blood flow in the superior mesenteric artery was assessed by Doppler flowmetry. Results: Blood flow in the superior mesenteric artery did not change significantly in group I. In group II, mesenteric blood flow increased significantly from baseline at 120, 150, and 180 minutes. Oxygen consumption in the mesenteric circulation increased significantly in group II at 90 and 180 minutes compared to baseline, as well as oxygen extraction. Lactate content in the mesenteric vein in group II increased compared to control at 30, 90 and 180 minutes. Conclusion: Overall gastrointestinal blood flow is not impaired during cardiopulmonary bypass in this animal model. Instead, gastrointestinal blood flow increased during normothermic cardiopulmonary bypass as well as oxygen consumption.

Cardiopulmonary bypass - Gastrointestinal blood flow

References

• 1 Lazar H L, Hudson H, McCann J. et al . Gastrointestinal complications following cardiac surgery.   Cardiovasc Surg. 1995;  3 341-344
• 2 Ohri S K, Desai J B, Gaer J A. et al . Intraabdominal complications after cardiopulmonary bypass.  Ann Thorac Surg. 1991;  52 826-831
• 3 Tsiotos G G, Mullany C J, Zietlow S, van Heerden J A. Abdominal complications following cardiac surgery.  Am J Surg. 1994;  167 553-557
• 4 Christenson J T, Schmuziger M, Maurice J, Simonet F, Velebit V. Gastrointestinal complications after coronary artery bypass grafting.  J Thorac Cardiovasc Surg. 1994;  108 899-906
• 5 Lawhorne T W, Davis J L, Smith G W. General surgical complications after cardiac surgery.  Am J Surg. 1978;  136 254-256
• 6 Krasna M J, Flancbaum L, Trooskin S Z. et al . Gastrointestinal complications after cardiac surgery.  Surgery. 1988;  104 773-780
• 7 Gennaro M, Ascer E, Matano R, Jacobowitz I J, Cunningham J N, Uceda P. Acute mesenteric ischemia after cardiopulmonary bypass.  Am J Surg. 1993;  166 231-236
• 8 Hanks J B, Curtis S E, Hanks B B, Andersen D K, Cox J L, Jones R S. Gastrointestinal complications after cardiopulmonary bypass.  Surgery. 1982;  92 394-400
• 9 Moneta G L, Misbach G A, Ivey T D. Hypoperfusion as a possible factor in the development of gastrointestinal complications after cardiac surgery.  Am J Surg. 1985;  149 648-650
• 10 Gaer J A, Shaw A D, Wild R. et al . Effect of cardiopulmonary bypass on gastrointestinal perfusion and function.  Ann Thorac Surg. 1994;  57 371-375
• 11 Firmin R K, Boulos P, Allen P, Lime R C, Lincoln L CR. Sympathoadrenal function during cardiac operations in infants with the technique of surface cooling, limited cardiopulmonary bypass, and circulatory arrest.  J Thorac Cardiovasc Surg. 1985;  90 729-735
• 12 Minami K, Körner M M, Vyska K, Kleesiek K, Knobl H, Körfer R. Effects of pulsatile perfusion on plasma catecholamine levels and hemodynamics during and after cardiac operations with cardiopulmonary bypass.  J Thorac Cardiovas Surg. 1990;  99 82-91
• 13 Taylor K M, Bain W H, Russel M, Brannan J J, Morton I J. Peripheral vascular resistance and angiotensin II levels during pulsatile and nonpulsatile cardiopulmonary bypass.  Thorax. 1979;  34 594-598
• 14 Taylor K M, Bain W H, Morton J J. The role of angiotensin II in the development of peripheral vasoconstriction during open-heart surgery.  Am Heart J. 1980;  100 935-937
• 15 Reilly P M, Bulkley G B. Vasoactive mediators and splanchnic perfusion.  Crit Care Med. 1993;  21 S55-S68
• 16 Fiddian Green R G. Gut mucosal ischemia during cardiac surgery.  Semin Thorac Cardiovasc Surg. 1990;  2 389-399
• 17 Lees M H, Herr R H, Hill J D. et al . Distribution of systemic blood flow of the rhesus monkey during cardiopulmonary bypass.  J Thorac Cardiovasc Surg. 1971;  61 570-586
• 18 Ohri S K, Becket J, Brannan J, Keogh B E, Taylor K M. Effects of cardiopulmonary bypass on gut blood flow, oxygen utilization, and intramucosal pH.  Ann Thorac Surg. 1994;  57 1193-1199
• 19 Lazenby W D, Ko W, Zelano J A. et al . Effects of temperature and flow rate on regional blood flow and metabolism during cardiopulmonary bypass.  Ann Thorac Surg. 1992;  53 957-964
• 20 Tao W, Zwischenberger J B, Nguyen T T. et al . Gut mucosal ischemia during normothermic cardiopulmonary bypass results from blood flow redistribution and increased oxygen demand.  J Thorac Cardiovasc Surg. 1995;  110 819-828
• 21 Leitman I M, Paull D E, Barie P S, Isom O W, Shires G T. Intra-abdominal complications of cardiopulmonary bypass operations.  Surg Gynecol Obstet. 1987;  165 251-254
• 22 Ohri S K, Bowles C T, Siddiqui A. et al . The effect of cardiopulmonary bypass on gastric and colonic mucosal perfusion: a tonometric assessment.  Perfusion. 1994;  9 101-108
• 23 Andersen L W, Landow L, Baek L, Jansen E, Baker S. Association becween gastric intramucosal pH and splanchnic endotoxin, antibody to endotoxin, and tumor necrosis factor-alpha concentrations in patients undergoing cardiopulmonary bypass.  Crit Care Med. 1993;  21 210-217