Stent collapse caused by balloon occlusion and aspiration system in saphenous vein graft intervention.

We present the case of an 82-year-old male patient with unstable angina pectoris referred for percutaneous coronary intervention in the saphenous vein graft (SVG) to left circumflex coronary artery. An everolimus-eluting cobalt chrome stent was successfully deployed, using an embolic protection device with balloon occlusion and aspiration system. During the procedure of aspiration thrombectomy, the deployed stent unexpectedly collapsed. We re-dilated the collapsed stent using the same distal protection and aspiration system. However, the stent collapsed again during the aspiration procedure. As we could successfully re-dilate the collapsed stent using the same balloon occlusion and aspiration system after pulling the guide catheter out from the ostium of SVG, we concluded that the collapse of the stent was caused by the excess negative pressure generated by the distal occlusion and aspiration procedure under the completely wedged guide catheter into the ostium of SVG. We believe this is the first report of stent collapse due to excess negative pressure during aspiration thrombectomy. < Since the radial strength of coronary stents is high enough, deployed stent collapse is a rare complication. This case report describes a novel mechanism of stent collapse, which was caused by the excess negative pressure generated by the distal occlusion and aspiration procedure in saphenous vein graft intervention. To avoid this type of complication, in using distal protection devices, the side-hole guide catheter should be used, or the guide catheter should be carefully manipulated not to be wedged.>.