Intravascular ultrasound-guided tip-detection antegrade dissection and re-entry as a bailout strategy for calcification-induced side-branch occlusion during complex percutaneous coronary intervention: a case report.

Background: Percutaneous coronary intervention (PCI) for heavily calcified bifurcation lesions presents unique challenges, side-branch occlusion representing a serious complication. Tip-detection antegrade dissection and re-entry (TD-ADR), originally developed for chronic total occlusion, enables true lumen re-entry when guidewires advance subintimally. We report its novel application as an effective bailout technique for calcification-induced side-branch occlusion. Case summary: A 67-year-old man with prior inferior myocardial infarction underwent PCI of a heavily calcified mid-left anterior descending (LAD) artery stenosis with ostial narrowing of diagonal branches D1 and D2. Rotational atherectomy and modified balloon dilation fragmented the calcific plaque, abruptly displacing fragments that occluded the D2 ostium. Conventional re-crossing attempts with multiple wires resulted in subintimal tracking. Intravascular ultrasound (IVUS) confirmed the guidewire entered the false lumen at D2 origin. Using a double-guide catheter setup and IVUS guidance, TD-ADR with a Conquest Pro 12 ST guidewire targeted the true lumen point, achieving precise re-entry and restoring TIMI 3 flow to D2. Culotte stenting of LAD and D2 was subsequently performed. Discussion: In calcified bifurcation interventions, plaque fracture during lesion preparation can directly obstruct side-branch ostia and render conventional guidewire re-crossing techniques ineffective. When guidewires enter the subintimal space and angiography-guided re-entry fails, IVUS-guided TD-ADR can pinpoint and penetrate the true lumen vertically, minimizing subintimal tracking, preserving side-branch perfusion, and providing a reliable bailout. This case demonstrates the utility of IVUS-guided TD-ADR as a targeted bailout strategy for achieving true lumen access in difficult side-branch occlusions during complex bifurcation PCI.