Emergency Leaflet Perforation for Coronary Revascularization Following Delayed Chimney Stent Complete Occlusion: A Case Report

ABSTRACT Coronary obstruction is a rare but potentially fatal complication of transcatheter aortic valve replacement, particularly in patients with high‐risk anatomy. Prophylactic techniques such as chimney stenting and intentional leaflet laceration have been developed to prevent acute coronary obstruction; however, delayed coronary obstruction (DCO) remains a serious concern. We present a 76‐year‐old woman with severe aortic stenosis, low coronary height, and an elongated native left coronary cusp. Preprocedural computed tomography and virtual simulation revealed a near‐zero valve‐to‐sinotubular junction distance, predicting unavoidable obstruction. Despite chimney stenting during self‐expanding valve deployment, progressive valve frame expansion caused late chimney stent occlusion. Emergent revascularization was achieved by mechanically perforating the entrapped native leaflet, followed by fenestration stenting. This case highlights the limitations of conventional coronary protection in preventing DCO. It demonstrates that percutaneous leaflet perforation with fenestration stenting may serve as a potentially feasible bailout strategy in this high‐risk setting.