Left coronary to right ventricle fistula in a child: management strategy based on cardiac-gated 64-slice CT

Diagnosis and therapeutic management of coronary artery fistulae is still an open issue. ECHO is the first-line examination for a suspected coronary fistula. Transoesophageal ECHO and invasive angiography are traditionally considered the reference examinations to demonstrate the anatomy of the malformation. However, conventional angiography and transoesophageal ECHO are invasive procedures based on 2-D representation and they sometimes fail to demonstrate the spatial relationship and connections of fistulae. New-generation MSCT is becoming a fundamental tool for evaluation of several coronary artery diseases in adults and children [1]. In our patient, accurate evaluation of the anomaly was achieved using multiplanar and 3-D reconstructions. MSCT findings led us to confirm the diagnosis and plan percutaneous occlusion because of the favourable anatomy and the absence of collateral coronary branches in proximity to the occlusion site. Moreover, MSCT was instrumental in the selection of coils as the modality of occlusion and in providing clear images useful to guide the procedure. Indeed, retrograde closure by plugs was excluded because of the distal position of the fistula, its tortuous course and small diameter. Antegrade closure was considered technically challenging because of the sharp angulation between the coronary fistula and the right ventricular apex.

When diagnosed during infancy or childhood, most isolated coronary fistulae are asymptomatic. The decision to treat or observe during infancy and childhood is controversial. Because several complications may occur in later life, some authors suggest early closure [2]. However, in the absence of symptoms, others advocate conservative management based on the experience that coronary fistulae do not have an adverse clinical outcome in childhood and adolescence [3]. In our patient, we decided to occlude the fistula because although the chest pains were not typical for myocardial ischaemia, their recurrent nature was a handicap for the patient and his family.

Possible treatments of coronary artery fistulae include surgical closure and transcatheter embolization [3]. When surgery is preferred, the majority of patients are treated by surgical ligature under cardiopulmonary bypass; however, in selected patients, an approach without the use of a cardiopulmonary bypass is feasible. Surgical outcome is generally excellent [3]. Other authors advocate transcatheter occlusion as a reasonable alternative to surgery. Indeed, the successful use of different coils and devices is widely reported in the literature [4]. However, in some patients the fistula anatomy may not be favourable for percutaneous treatment [5]. The main criteria that influence the decision as to which treatment option to use are the anatomical features of the malformation. Short angulated fistulae draining close to the tricuspid annulus and giving origin to collateral branches in proximity to the occlusion site may be clear contraindications to percutaneous closure. Based on the anatomical evaluation the management strategy for coronary fistulae should be determined on an individual basis for each patient.

In conclusion, we underline that MSCT is an invaluable tool to confirm the diagnosis of coronary fistula and to provide anatomical information useful to plan the best therapeutic strategy.