Coil Occlusion of Coronary Cameral Fistula: A Case Report

Introduction :

Coronary artery fistulas (CAFs) are the communication between a coronary artery and the system (artery or vein) or the pulmonary artery (including the coronary sinus) or any of the four cardiac chambers of the heart. If the connection is to one or multiple chambers of the heart, it is termed a coronary-cameral fistula.1 It constitutes 0.2-0.4% of all congenital cardiac defects. The incidence is similar between males and females. Most of the patients with coronary artery fistula are asymptomatic. On the other hand shunt through fistula can be so large that congestive heart failure occurs. In young adults, symptoms like atrial fibrillation, fatigue, exertional dyspnoea or ischaemic chest pain may appear but symptoms are usually rare before 20 years of age.2,3 Angina pectoris is seen in 80% of these patients after 50 years of age. Color Doppler Echocardiography is the diagnostic test by which dilated coronary artery and the fistula including its entry point can be visualized. Most of the fistula including small ones should be closed to prevent infective endocarditis, congestive cardiac failure, and myocardial ischemia. Surgical ligation of fistula has long been established. Percutaneous coil embolization or closure with vascular plug is gaining rapid popularity as these are safe, effective and a patient can avoid thoracotomy scar and long invasive procedure as well.

Case report:

‘T’, a two years old male child was diagnosed as a case of coronary cameral fistula from a right coronary artery (RCA) to the right atrium (RA) since twenty third month of his age. He had a history of recurrent respiratory tract infection since early infancy along with failure to thrive. In one occasion of respiratory infection one month ago, he was seen by a pediatrician and murmur was detected. He was referred to pediatric cardiologist of Combined Military Hospital (CMH) Dhaka and cardiac workup was done. His ECG showed left ventricular hypertrophy (LVH) and chest X-ray showed mild cardiomegaly with plethoric lungs field. Echocardiography of ‘T’ with color Doppler detected a fistulous communication between a right coronary artery and right Atrium with a left to right shunt. He was treated initially with anti-failure medicines for about a month and then he was taken into the catheterization laboratory of Combined Military Hospital (CMH) Dhaka on 15th August 2010 with an intention of trans catheter closure of fistula with
detachable PDA coil.

Procedure Equipment:

1. JR, Cook, Multipurpose and Pigtail catheter.
2. Normal pediatric drape and puncture set.
3. PDA coil, size 5×4, coil delivery system.
The procedure was performed under deep sedation with injection Ketamine and Diazepam. After draping, right femoral artery and vein were cannulated with 5F and

6F sheath. Aortogram was performed in different views to bring the entire course of fistula in a good profile. RCA was engaged with a JR-4 catheter and was exchanged with Cook 5F multipurpose catheter. The narrowest point of the fistula was 2.5 mm. So a 5×4 mm coil (Cook coil) was loaded in the delivery cable. Delivery cable was then forwarded through the catheter and the narrowest point was crossed. The appropriate position was checked by dye injection using Manifold. Two of the coils were delivered distal to the narrowest part towards the right atrium and rest two coils were released proximal to the narrowest part and towards RCA. Precaution was taken not to occlude any of the branches of the right coronary artery and to hamper coronary circulation. Coil was than released from the delivery cable by unscrewing. Aortogram performed with pigtail showed total occlusion of the fistula and patency of the right coronary system. ECG and cardiac enzymes were done 6 hours and 12 hours after the procedure and were normal. Echocardiogram showed no residual fistulous communication. A patient was discharged 48 hours after the procedure.

Discussion:

A coronary cameral fistula is a rare anomaly involving a vascular communication between a coronary artery
and a cardiac chamber. They are often caused by aberrancies of normal embryological development4. The major sites of fistula are the right coronary artery (55%), left coronary artery (35%), and a combination of both coronary arteries (5%). Termination sites are the right ventricle (40%), right atrium (26%), pulmonary arteries (17%) and less frequently, the superior vena cava or coronary sinus5-7. Most coronary fistulae are congenital, and these are the most haemodynamically significant primary coronary anomalies5. The clinical features depend on the size and site of the fistula which ranges from a continuous murmur in asymptomatic children to congestive heart failure in symptomatic infants. Coronary fistula can be closed either surgically or by trans catheter approach. The transcatheter approach has a definite advantage over surgical ligation. The transcatheter approach is a low-cost procedure with less morbidity and hospital stay and moreover, a thoracotomy can be avoided13. There are various techniques for trans catheter closure which includes coil embolization and vascular plug etc14,15. If fistula left untreated then there will be a chance of myocardial ischemia, thromboembolization, aneurismal dilatation, endarteritis, congestive cardiac failure, arrhythmia, and rupture16,17. Though most of the fistula can be closed by interventional technique, complications like distal embolization of coil or dissection have been reported18,19. Amplatzer vascular plug is a very good device for closing coronary fistula, but considering the small diameter of the narrowest part of the fistula in this case near the right atrium, PDA detachable coil was used. The successful outcome of this case suggests that coil embolization is a safe and cost elective mean for closing coronary cameral fistula.

Conclusion:

Interventional occlusion of coronary artery fistula has become a well-accepted alternative to surgical therapy in many centers. In the present case myocardial enzyme analysis, electrocardiography and wall motion in echocardiography was completely within a normal limit with 48 hours of the procedure. So this procedure has proved itself as the effective one in our center also.