Occlusion test-guided ligation of an aneurysmal sinus node artery feeding a recanalized fistula

A 23-year-old man presented with one year of exertional dyspnoea. Computed tomography angiography showed an aneurysmal right coronary artery (ostium 10 mm, proximal segment 11 mm) giving rise to a 13-mm sinus node artery aneurysm draining into lateral right atrial wall through a 9-mm fistula; left ventricular ejection fraction was 65%. 4-mm intra-atrial orifice was closed with pledgeted sutures and extracardiac tract ligated, preserving the sinus node artery, he was discharged on postoperative day 7. One year later the fistula had recanalized, with coronary ostium enlarged to 11.8 mm and the aneurysm to 15.6 mm. At reoperation the proximal sinus node artery was snared under continuous electrocardiographic monitoring; P waves persisted at 3 and 5 minutes (70 and 75 beats/min), and definitive ligation and division followed. P waves were absent between 7 and 19 minutes, at 70 to 73 beats/min, and returned spontaneously at 20 minutes. At 6 months he was asymptomatic and in sinus rhythm, with no residual fistula and regression of right coronary artery to 7.4 mm. Temporary occlusion testing guided sinus node artery ligation, but delayed sinus node dysfunction may occur, requiring continuous rhythm monitoring.