Stent deformation and dislodgment into the aorta during mini-crush bifurcation PCI: a rare complication leading to emergency CABG.

BACKGROUND: Stent dislodgment during percutaneous coronary intervention (PCI) has become exceedingly rare with modern stent designs; however, it may still occur in complex bifurcation interventions. When the event involves the left main coronary artery (LMCA), the consequences may be catastrophic. A 65-year-old woman presented with anterolateral myocardial infarction. Coronary angiography revealed severe LAD-D1 bifurcation disease (LAD 90% after D1, D1 total occlusion) without significant calcification (Fig. 1). A mini-crush technique was planned using a 7 F JL4 guiding catheter. Following predilatation, a 2.75 × 13 mm DES was successfully deployed in D1, while a 2.75 × 18 mm DES had been pre-positioned ("parked") in the LAD at the D1 level (Fig. 2). During withdrawal of the D1 stent balloon, the pre-positioned LAD stent became deformed, slipped from the balloon, and partially dislodged, hanging from the LMCA into the aorta (Fig. 3). Multiple retrieval attempts using LCB, EBU4, EBU3.5, and JL3.5 guide catheters and micro and macro snare systems were unsuccessful (Fig. 4). Heart team consultation recommended emergency coronary artery bypass grafting (CABG). The patient underwent LIMA-LAD, Ao-saphenous vein graft (SVG) to OM2, and Ao-SVG to D1. Intraoperative findings revealed that the slipped LAD stent was tightly embedded within the D1 stent and fractured during removal attempts. At 7-month follow-up, the patient remained asymptomatic with preserved LV function (EF 55%).

DISCUSSION: This case highlights an important complication of bifurcation PCI. Pre-positioning ("parking") of the main-vessel stent during mini-crush may carry an underrecognized risk of deformation and loss during side-branch balloon withdrawal, even in the absence of calcification or tortuosity.

CONCLUSION: Operators should be aware that stent parking in bifurcation PCI can predispose to balloon-stent interactions that may result in deformation, dislodgment, or embolization.