Comparing short versus standard-length balloon for intra-aortic counterpulsation: results from a porcine model of myocardial ischaemia-reperfusion.

OBJECTIVES: We compare a short and a standard-size balloon with same filling volumes to verify the differences in terms of visceral flow, coronary circulation and haemodynamic performance during aortic counterpulsation in an animal model of myocardial ischaemia-reperfusion injury.
METHODS: Eighteen healthy pigs underwent 120-min ligation of the left anterior descending coronary artery followed by 6 h of reperfusion, and they were randomly assigned to have intra-aortic balloon counterpulsation (IABP) with a 40-ml short-balloon (n = 6) or a 40-ml standard-length balloon (n = 6), or to undergo no IABP implantation (controls, n = 6). Haemodynamics and visceral and coronary flows were measured at baseline (t0), at 2 h of ischaemia (t1) and every hour thereafter until 6 h of reperfusion (from tR1 to tR6), respectively.
RESULTS: Mesenteric flows increased significantly at tR1 only in the short-balloon group (P < 0.001) and it was constantly higher than in the standard-balloon group regardless of mean arterial pressure, systemic vascular resistance and cardiac output (CO; all, P < 0.001). Renal blood flows were significantly increased during IABP treatment with values constantly and significantly higher in short balloons at any following experimental step (all, P < 0.05). IABP improved CO and coronary blood flow, and reduced afterload, myocardial resistances and myocardial oxygen consumption without differences between the short and the standard-length balloon (all, P > 0.05).
CONCLUSIONS: The short balloon prevents visceral ischaemia and, compared with the standard-size balloon, it does not lose IABP beneficial cardiac and coronary-related effects. Further studies are warranted to confirm our findings.