Excessive Ostial Stent Protrusion: Evaluation of Management Strategies and Clinical Outcomes of the Side Flap Technique

Abstract

Backgrounds: Accurate stent positioning in aorto-ostial lesions remains challenging due to complex three-dimensional anatomy, lack of optimal fluoroscopic projections, and high rates of geographic miss. Stent overhang impairs guide catheter re-engagement and complicates future revascularization. Despite its frequency, no standardized approach exists for managing excessive stent protrusions. Aims: This study systematically evaluated management strategies for excessive aorto-ostial stent protrusion, integrating comprehensive bench testing with clinical case experience, and assessed the feasibility, mechanics, and outcomes of the Side Flap technique. Methods: Bench experiments assessed multiple corrective strategies in two scenarios, guidewire crossing through the central stent lumen and through a side cell, across contemporary DES platforms. Mechanical feasibility, force transmission, stent deformation and expansion, and structural integrity were evaluated using high-pressure ballooning, catheter-assisted maneuvers, and intracoronary imaging. A retrospective multicenter series provided complementary real-world clinical outcomes of the Side Flap technique. Results: Longitudinal stent compression using guide catheters, large balloons, or telescoping maneuvers proved mechanically ineffective and frequently produced severe stent deformation or malapposition. In contrast, intentional side-cell recrossing with creation of a neo-lumen was consistently feasible, structurally stable, and reproducible. All DES platforms tolerated large-diameter side-cell expansion without strut fracture, yielding circular neo-lumens with excellent apposition on OCT. Clinically, the Side Flap technique achieved high procedural success with no technique-related adverse events during follow-up. Conclusions: The Side Flap technique offers a controlled and reproducible alternative strategy when true-lumen access is not achievable or fails, and represents a valuable addition to the interventional armamentarium. Longitudinal stent crush techniques are unreliable for managing excessive aorto-ostial protrusion.