[Selective continuous coronary perfusion via an angioplasty catheter following acute vascular occlusion]

Since surgical revascularisation after PTCA-induced acute coronary occlusion in the majority of cases is delayed by at least 2 hours, we assessed the possibility of selective, volume-controlled coronary perfusion via the still indwelling angioplasty catheter for such a prolonged period using an external pump. Because of the high pressures required to provide adequate flow through many of the currently used catheters, an AC independent, pressure and volume controlled pump was developed which does not cause substantial hemolysis even at pressures beyond 10 atm. During in vitro tests the pressure-flow-rate relations and the degree of hemolysis and blood count changes were determined for various catheters. The previous catheters with a fixed wire tip caused excessive hemolysis which rendered prolonged coronary perfusion prohibitive. But even with the more recent catheters the presence of side holes near the catheter tip may at times cause significant hemolysis. In 20 out of 22 dogs the anterior descending (n = 18) or circumflex (n = 2) coronary artery was selectively perfused for 2 hours following balloon occlusion. The perfusion rate was adjusted according to the occurrence of ischemic signs in the ECG and for a drop in the coronary venous oxygen saturation which was monitored with a fiberoptic catheter. The intraluminal pressure within the selectively perfused vessel was recorded continuously but not used for adjustment of the perfusion rate. In no case was there a critical pressure increase in the selectively perfused vessel. When perfusion of the occluded vessel was stopped after 2 hours, massive myocardial ischemia developed which was reversible with resumption of perfusion. Using an adequate pump and the more recent, steerable angioplasty catheters which should not have side holes near the tip, selective coronary perfusion can be performed for at least 2 hours and is capable of preventing myocardial ischemia.