Ventricularis Delamination Causing Acute Left Main Obstruction During TAVI: a case report

Abstract

Acute coronary obstruction is a rare but potentially fatal complication of transcatheter aortic valve implantation (TAVI), most commonly resulting from displacement of a calcified native leaflet. We describe an unusual mechanism involving delamination of native aortic leaflet tissue with subsequent coronary ostial obstruction. An 80-year-old woman with severe symptomatic calcific aortic stenosis underwent transfemoral TAVI with a self-expanding valve. During valve deployment, she developed abrupt haemodynamic collapse with marked ST-segment elevation. Emergency angiography demonstrated acute left main coronary obstruction, while transoesophageal echocardiography revealed a newly developed mobile flap-like structure in the ascending aorta, raising concern for acute aortic dissection. Emergency surgical exploration excluded aortic dissection and demonstrated delamination of native aortic leaflet tissue, macroscopically considered to involve the ventricularis layer. The detached tissue had prolapsed into the left coronary ostium, causing mechanical obstruction of coronary inflow. Excision of the obstructing tissue and surgical aortic valve replacement restored coronary perfusion. This case expands the mechanistic spectrum of TAVI-related coronary obstruction and highlights an important diagnostic pitfall. Native leaflet delamination may produce a mobile intra-aortic flap mimicking acute aortic dissection while simultaneously causing catastrophic coronary obstruction. Recognition of this rare mechanism may facilitate prompt diagnosis and appropriate rescue intervention.