Impact of Acute Intestinal Ischemia and Reperfusion Injury on Hemodynamics and Remote Organs in a Rat Model

Abstract

Background: Acute mesenteric ischemia following cardiovascular surgery is a rare but fatal complication. We established a new rat model for hemodynamic monitoring during mesenteric ischemia/reperfusion (I/R) and evaluated the impact of mesenteric I/R on hemodynamics and remote organ injury.

Methods: Mesenteric I/R was induced in male Wistar rats by superior mesenteric artery occlusion for 90 minutes, followed by 120 minutes of reperfusion. Before I/R, ventilation and hemodynamic monitoring including mean arterial blood pressure (MAP) and cardiac output (CO) were established. During reperfusion Geloplasma (I/R + Geloplasma, N = 6) and Ringer's solution (I/R + Ringer, N = 6) were titrated according to CO and compared with I/R without volume resuscitation (I/R only, N = 6) and a sham group (sham, N = 6). Blood samples were regularly taken for serum marker measurements. After reperfusion organs were harvested for histology studies.

Results: After acute mesenteric I/R, MAP and CO decreased (p < 0.01) while systemic and pulmonary vascular resistance increased (p < 0.01) continuously in the I/R group. Volume substitution according to CO initially stabilized hemodynamic parameters, but CO declined independently in the late stage. Compared with the I/R + Ringer group, the I/R + Geloplasma group required less volume for resuscitation (p < 0.01), experienced less metabolic acidosis. I/R groups had more organ injuries, more neutrophils sequestration, and higher creatine phosphokinase-MB levels than sham group.

Conclusion: A new model for CO monitoring after mesenteric I/R injury demonstrated severe hypovolemic shock during reperfusion followed by remote myocardial and lung injury. Far less colloid volume is needed for hemodynamic stabilization after I/R compared with crystalloid volume.