Coronary artery fistulae account for about 0.2–0.3% of all congenital heart defects, and are observed in about 0.2–4.9% of coronary angiograms. Most commonly, the fistulae involve the right coronary artery (55%), the left coronary (35–44%) or both arteries (5–10%). They may drain into the right ventricle (41%), right atrium (26%), pulmonary artery (17%) and coronary sinus (7%). We report how transoesophageal echocardiography (TOE) facilitates surgical fistulae closure.
A 56-year-old man was referred for closure of bilateral coronary artery fistulae. He had a 6-month history of exertional dyspnoea accompanied by atrial fibrillation. Pre-operative catheter examination showed coronary artery fistulae arising from a dilated right coronary artery (11.5 mm) and left circumflex artery (6 mm), and these arteries were suspected to drain into the coronary sinus. Analysis of oxygen saturation indicated a 59% left-to-right shunt at the atrial level. Surgery was planned to stop the shunt by closing the origin and drainage sites of both coronary artery fistulae, and placing bypass grafts to the proximal normal coronary arteries.
Intra-operative TOE confirmed both coronary artery fistulae drained into the coronary sinus. Turbulent flow created a mosaic echo in the dilated coronary sinus (15 mm) seen on the pre-operative mid-oesophageal TOE view of the coronary sinus (Fig. 1). After coronary bypass grafts to the proximal normal right coronary artery and circumflex branch of the left coronary artery, the origins of both aneurysms were ligated using an off-pump procedure. No regional wall-motion abnormalities were detected on TOE, and ST segment elevation was seen only briefly. Additional occlusion procedures were performed by banding the drainage site with patches. Coronary sinus flow decreased to normal levels (maximum 30 cm.s−1). Turbulent flow (mosaic echo) around coronary sinus was diminished on the postoperative TOE mid-oesophageal view (Fig. 2).
This case illustrates how TOE examination can facilitate intra-operative evaluation of coronary artery fistulae, especially when performing surgery ‘off-pump’.