Ann Thorac Surg 2004;78:e26-e27
© 2004 The Society of Thoracic Surgeons
Case report
Coronary artery to the left atrial fistula after resection of atrial appendages
Phong Nguyen-Do, MBBSa,
Paul Bannon, FRACS, PhDb,
Dominic Y. Leung, FRACP, PhD*a
a Department of Cardiology, Liverpool Hospital, University of New South Wales, Liverpool, Australia
b Department of Cardiothoracic Surgery, Liverpool Hospital, University of New South Wales, Liverpool, Australia
Accepted for publication October 24, 2003.
* Address reprint requests to Dr Leung, Liverpool Hospital, Locked Bag 7017, Liverpool BC NSW 1871, Australia
e-mail: d.leung{at}unsw.edu.au
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Abstract
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We report the case of a fistula formation between the left circumflex coronary artery draining into the left atrium as a complication of radiofrequency cardio-ablation and resection of the atrial appendages. This complication was diagnosed with the use of transesophageal echocardiography and was subsequently confirmed on coronary angiography.
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Introduction
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Radiofrequency cardio-ablation of the left atrium (Cox-Maze technique) during valve surgery is increasingly being used to treat atrial fibrillation. It is associated with a high cure rate for atrial fibrillation and a low incidence of complications [1, 2]. We report the case of a fistula between a left atrial branch of the left circumflex coronary artery and the left atrium after aortic and mitral valve replacement and radiofrequency cardio-ablation with resection of the atrial appendages. This complication was diagnosed with the use of transesophageal echocardiography and was confirmed subsequently on coronary angiography.
A 55-year-old man was admitted electively for aortic and mitral valve replacement and radiofrequency cardio-ablation for atrial fibrillation. He was known to have severe aortic regurgitation, moderate mitral regurgitation and moderate tricuspid regurgitation on the basis of chronic rheumatic heart disease. Preoperative transthoracic echocardiography revealed a grossly dilated left atrium, moderate mitral and tricuspid regurgitation, and severe aortic regurgitation. The left ventricular function was normal with mild concentric hypertrophy. Preoperative coronary angiography revealed normal coronary arteries. Intraoperatively, the patient underwent standard cardiopulmonary bypass. Radiofrequency cardio-ablation was performed with standard techniques through separate right and left atriotomies (Fig 1). The radiofrequency probe was irrigated with normal saline. Both the left and right atrial appendages were excised and oversewn. The mitral and aortic valves were then replaced with bi-leaflet tilting disc valves. Cardiopulmonary bypass was weaned uneventfully, and the patient was converted to a junctional rhythm. However, he reverted back into atrial fibrillation with controlled ventricular response on postoperative day 5.
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Fig 1. The pattern of cardio-ablation within the left atrium (dotted line). The location of the mitral annulus is indicated.
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Transthoracic and transesophageal echocardiograms were performed in the second week after the operation. A high velocity (3 m/s), continuous jet was seen in the left atrium near the orifice of the truncated left atrial appendage. The appearance of the jet is suggestive of a coronary artery to the left atrial fistula with the origin of the jet near the vicinity of the course of the left circumflex coronary artery along the left atrial-ventricular groove (Fig 2). Both prosthetic valves were functioning normally. A provisional diagnosis of coronary artery fistula was made. It was subsequently confirmed by coronary angiography, which revealed a fistulous tract arising from an enlarged left atrial branch of the circumflex coronary artery and draining into the left atrium (Fig 3). We elected to treat the patient conservatively with regular follow-up. Our patient underwent direct current cardioversion 1 week postoperatively, which restored his sinus rhythm. He had symptomatic junctional bradycardia 2 weeks postoperatively, which required the insertion of a dual chamber permanent pacemaker. He was subsequently discharged. A follow-up at 6 months after his discharge revealed that he was in sinus rhythm. At another follow-up 9 months after discharge, a transesophageal echocardiogram revealed that the fistula flow into the left atrium was no longer visible.
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Fig 2. (A) Color Doppler transesophageal echocardiography shows a continuous, high velocity flow (arrows) into the left atrium near the truncated left atrial appendage suggestive of coronary artery fistula. (LA = left atrium; MV = mitral valve; PV = left pulmonary vein.) (B) Continuous wave Doppler revealed a high velocity continuous jet draining into the left atrium.
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Fig 3. Angiographic study of the left coronary artery showing contrast flow into the left atrium (white arrows) through a left atrial branch (black arrows) of the left circumflex artery.
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Comment
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Coronary artery fistulae have been reported as complications of cardiac surgery such as cardiac transplantation. The reported angiographic incidence ranges from 5.4% to 14%. These complications may occur as a result of multiple endomyocardial biopsies. Fistulae from an atrial branch of the circumflex coronary artery to the left atrium after heart transplantation have been reported [3]. These fistulae were believed to be a result from surgical technique. Similar to our patients, these fistulae were initially diagnosed by transesophageal echocardiography with color and pulsed-wave Doppler. These patients remained asymptomatic after 1-year follow-up, with no treatment required.
Mohr and colleagues [1] described development of atrio-esophageal fistula in 3 of 188 patients (1.3%) who underwent radiofrequency cardio-ablation with and without valvular surgery. The cause of this complication was believed to be due to thermal injury during radiofrequency application in combination with mechanical trauma by the echocardiographic probes. There have been no reported complications of atrio-coronary fistula as a result of radiofrequency cardio-ablation and resection of atrial appendages. Sie and colleagues [2] described a series of 30 patients with chronic atrial fibrillation who underwent radiofrequency ablation during single or double-valve surgery. They used radiofrequency energy to create long linear lesions in both atria as a modification of the MAZE III procedure. There were no reported complications of atrio-coronary fistula.
The diagnosis in our patient was first made with transesophageal echocardiography. On color flow Doppler, a high velocity continuous jet was noted flowing into the left atrium near the orifice of the left atrial appendage, the body of which has been resected. This anatomical position, as well as the velocity and continuous nature of the jet, raised the suspicion of a coronary artery fistula from the left circumflex coronary artery rather than flow from the pulmonary vein. This led to the provisional diagnosis, which was later confirmed by coronary angiography.
The natural history and therefore the treatment needed for this complication are unclear. Most coronary artery fistulae can be closed with percutaneous transcatheter techniques. There have been reports describing the use of coils, double-umbrella [4], detachable balloons, and polyvinyl foam [5] to close congenital or iatrogenic coronary fistulae. We elected to observe our patient as the shunt did not appear to be significant, and follow-up transesophageal echocardiography demonstrated resolution of the fistula flow. The exact mechanism of the creation of the fistula in our patient was unclear, but we postulated that it was more likely to be related to the resection of the left atrial appendage rather than the cardio-ablation.
This case illustrates a possible complication of coronary-atrial fistula formation in patients undergoing radiofrequency cardio-ablation with resection of atrial appendages. Transesophageal echocardiography has been a useful tool to diagnose the circumflex coronary artery to the left atrial fistula in our patient.
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References
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- Mohr F.W., Fabricius A.M., Falk V., et al. Curative treatment of atrial fibrillation with intraoperative radiofrequency ablation: short-term and midterm results. J Thorac Cardiovasc Surg 2002;123(5):919-927.[Abstract/Free Full Text]
- Sie H.T., Beukema W.P., Misier A.R. Radiofrequency ablation of atrial fibrillation in patients undergoing valve surgery. Circulation 1997;96(Suppl):I-450.
- Gascuena R., Lombera F., Fernandez S., et al. Left circumflex coronary artery-to-left atrium fistulae detected by transesophageal echocardiography in heart transplant recipients. Echocardiography 2000;17(5):443-445.[Medline]
- Perry S.B., Rome J., Keane J.F., et al. Transcatheter closure of coronary artery fistulae. J Am Coll Cardiol 1992;20(1):205-209.[Abstract]
- Hartnell G.G., Jordan S.C. Balloon embolization of a coronary arterial fistula. Int J Cardiol 1990;29:381-383.[Medline]
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Abstract
Introduction
