Left Main Restenosis Due to a Retained Balloon Shaft: A First Report.

BACKGROUND: Retained intracoronary devices are rare percutaneous coronary intervention complications with thrombotic and mechanical consequences. CASE SUMMARY: A 77-year-old man undergoing preoperative coronary evaluation had left main bifurcation in-stent restenosis. Optical coherence tomography (OCT) showed well-apposed stents, fibrotic restenosis, and marked recoil despite repeated balloon dilatation; excimer laser coronary atherectomy was planned. Reassessment of the OCT pullback revealed a retained balloon catheter shaft extending from the left circumflex artery to the left main ostium, likely explaining refractory restenosis. Laser and cutting/scoring balloon strategies were considered unsafe. After heart team review, conservative management was selected because of prohibitive surgical risk. DISCUSSION: This case highlights the role of OCT in clarifying percutaneous coronary intervention failure and identifying occult retained material before potentially harmful intervention. TAKE-HOME MESSAGES: When restenosis is resistant to balloon preparation, OCT should be reviewed for foreign material. Once endothelialized, retained devices may be difficult to retrieve, and nonintervention may be safest.