Two Cases of Very Late Dislodgement and Transcatheter Retrieval of Pediatric Aortic Isthmus Stents During Re-Intervention.

Endovascular stent implantation is an established treatment for native and recurrent aortic coarctation in children. Stents are generally assumed to become endothelialized by neointima within months after implantation. Reported late complications include restenosis, aneurysm formation, and stent fracture. Very late complete stent dislodgement, however, has not been reported to date. We report two pediatric patients who experienced very late dislodgement of previously implanted aortic isthmus stents - each nearly seven years after implantation. In the first case, a stent implanted in infancy for recoarctation dislodged completely during technically difficult retrograde catheterization of the aortic valve in a child with Shone complex. In the second case, the majority of a fractured stent migrated into the ascending aorta during advancement of a long sheath for re-stenting of the isthmus. In both patients, the displaced stents were successfully retrieved percutaneously using snare systems, and definitive re-stenting was performed. Notably, displacement occurred without major aortic wall injury, suggesting limited long-term biological fixation. These cases demonstrate that even years after implantation, aortic isthmus stents placed in early childhood may not be firmly integrated into the vessel wall. Growth-related vascular remodeling, reduced wall apposition, and aneurysmal changes may contribute to progressive loss of anchoring. Catheter manipulation or sheath advancement can act as triggering events. Awareness of potential whole-stent mobilization is essential during re-interventions in pediatric patients with longstanding isthmus stents.