Coil embolization for giant left anterior descending artery aneurysm with coronary pulmonary artery fistula in an elderly patient: a case report.

Background: Giant coronary artery aneurysms (CAAs), defined as dilatations exceeding 20 mm or four times the reference vessel diameter, are rare and risk rupture or thrombosis. Coronary pulmonary artery fistulas may lead to grow aneurysm formation via chronic high-flow shunting. Their coexistence is rare in elderly patients without prior Kawasaki disease. Case summary: An 83-year-old woman with hypertension, dyslipidaemia, and type 2 diabetes mellitus was referred for evaluation of an abnormal mediastinal contour. Chest computed tomography showed a 43 × 33 mm left anterior descending artery aneurysm with a fistulous to the pulmonary artery, grown from 30 × 20 mm over 10 years. Right heart cardiac catheterization showed no evidence of pulmonary artery hypertension with a mild shunt flow (Qp/Qs: 1.15). Despite being asymptomatic, the aneurysm's size and growth warranted intervention. Considering her age and comorbidities, transcatheter coil embolization was selected over surgical or stent-based therapies. Coils were deployed using intravascular ultrasound (IVUS) and a balloon-assisted technique, successfully occluding the aneurysm without compromising distal flow. Follow-up angiography at 6 months and echocardiography up to 3 years confirmed sustained occlusion. Discussion: This case highlights that even in asymptomatic elderly patients, large and expanding CAAs with fistulas warrant careful evaluation due to the risk of rupture. Transcatheter coil embolization provided a safe and effective treatment alternative to surgery, especially in high-risk anatomical and clinical settings. IVUS and balloon assistance were critical to procedural success, and long-term follow-up demonstrated sustained aneurysm exclusion.