Rapid Transcatheter Occlusion of a Coronary Cameral Fistula Using a Three-Lobed Vascular Occlusion Plug

From the Shaare Zedek Medical Center, Jerusalem, Israel. The authors report no conflicts of interest regarding the content herein. Manuscript submitted March 2, 2009, provisional acceptance given March 13, 2009, and final version accepted April 7, 2009. Address for correspondence: David Meerkin, MD, Department of Cardiology, Shaare Zedek Medical Center, POB 3235, Jerusalem, 91031 Israel. E-mail: meerkin@SZMC.org.il

_______________________________________________ ABSTRACT: Transcatheter occlusion of coronary cameral fistulae has been well reported. In large fistulae multiple devices with prolonged procedures are often required for complete occlusion. We present the case of a large right coronary artery-to-right atrial fistula that was rapidly and simply occluded with the three-lobed Amplatzer Vascular Plug 2.

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J INVASIVE CARDIOL 2009;21:E151–E153 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 development. The major sites of origin of fistulae are the right coronary artery (RCA) (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 sinus.1–3 Rarely, they involve the left side of the heart. Catheter-based closure of large fistulae can be a complex and prolonged procedure.4,5 We describe the use of the new triple-lobed Amplatzer Vascular Plug II (AGA Medical Corp., Plymouth, Minnesota) to occlude a large right coronary-to-right atrial fistula in a relatively simple and short procedure. Case Report. A 20 year-old female presented 5 months post partum with recurrent syncope. She underwent extensive investigation and following exclusion of relevant pathologies was diagnosed as suffering from a conversion reaction. During her assessment, however, physical examination revealed a loud 3/6 pancyclical murmur heard best at the right sternal border. There was no evidence of heart failure. Echocardiography demonstrated normal left and right ventricles with no valvular pathology. A huge proximal RCA was noted feeding a fistula that emanated from the RCA approximately 2 cm from its origin (Figure 1). The fistula appeared to take a convoluted path emptying into the right atrium. To further clarify this finding, right and left heart catheterization were performed. Right-sided pressures were normal and a QP:QS of 1.3 was noted. The left coronary system was normal. In order to adequately demonstrate the right coronary system including the fistula, a 5 Fr pigtail catheter was advanced into the fistula from the aorta to a position beyond the continuation of the normal RCA. An 8 ml injection over 2 seconds using the ACIST automatic injector failed (ACIST Medical Systems, Inc., Eden Prairie, Minnesota) to adequately opacify the structure, thus a 10 ml injection of contrast over 1 second was performed. This demonstrated a very large, aneurysmatic and convoluted fistula leaving the RCA approximately 2 cm from its origin and progressing over more than 25 cm to the right atrium (Figure 2). Diameters of 10–13 mm were measured over the initial 5 cm of the fistula proximal to marked aneurysmal dilatation. Due to the fistula’s large diameter and favorable anatomy, the decision was made to attempt closure using the Amplatzer Vascular Plug II (VP II) (Figure 3) approaching the fistula from its arterial origin. An 8 Fr Judkins right 4 Launcher guiding catheter (Medtronic, Inc., Minneapolis, Minnesota) was advanced into the fistula beyond the narrow segment and into the first aneurysmatic portion. The VP II was advanced through the catheter and delivered to the distal catheter end. Due to its flexibility, the device did not result in straightening of the catheter. The plug was initially deployed at the distal end of the narrower fistula segment, but upon release of the third lobe, the entire plug slipped back, such that the proximal device end encroached on the RCA continuation. The device was immediately retrieved and following repositioning, redeployed more distally (Figure 4). Immediate contrast injection demonstrated reduced flow (Figure 5). Within 5 minutes only minimal flow was present. The device was released by unscrewing and reinjection demonstrated total occlusion of the fistula (Figure 6). Flow to the RCA was unimpeded. Two hours of electrocardiographic monitoring showed changes. Transthoracic echocardiography performed the next day and 1 month later demonstrated a patent proximal RCA, with normal flow and no flow to the fistula. The patient was treated with aspirin 100 mg daily for 6 months. Due to the proximal origin of the fistula, following its occlusion, the RCA had normal flow and thus no anticoagulation was prescribed. Had the takeoff of the fistula been at the distal RCA with a long dilated vessel segment and small coronary runoff following occlusion, anticoagulation would have been recommended. Computed tomographic (CT) angiography demonstrated that the device was well positioned the occluded fistula and normal RCA at 4 months post procedure. Discussion. Large coronary cameral fistulae have a variable natural history. A small percentage of cases may undergo spontaneous closure.2 In the remaining patients, indications for closure include increasing right-to-left shunt, left or right ventricular overload, myocardial ischemia from a steal syndrome, congestive cardiac failure and prevention of endocarditis. The treatment options for closure of large fistulae are surgical closure or catheter occlusion techniques. Until relatively recently, catheter-based closure of fistulae of such caliber was a major challenge. The principal technique was to define the narrowest point and attempt to deploy hardware (coils, plugs, balloons) so that a thrombus would be formed and the devices would not migrate.6,7 As such, the approach was almost exclusively venous, as multiple catheters were often required. Typically in a case such as this, the fistula would be occluded at its narrowest point with a balloon catheter and a nest of coils deployed leaning upon the balloon until stable and the balloon withdrawn from left to right without disrupting the nest. Such a procedure necessitates an arteriovenous loop with at least one arterial and probably two venous access sites required. Such a lengthy procedure is also associated with the risk of migration and embolization of one or more of the coils to the pulmonary bed.5 Nonetheless, these devices provided good results while saving the patient from surgery. The development of the initial Amplatzer vascular plug, provided a device that acts as the base for the occlusion. Its use has been reported in such fistulae.4,8 It is much more stable when appropriately sized (50% above the luminal diameter of the fistula), however, it is often not occlusive and residual flow continues. This can be treated with additional coils that are then deployed upstream to the plug, resulting in vessel occlusion. Due to its shape and dimensions, it requires significant upsizing to prevent migration. The new Amplatzer Vascular Plug II potentially offers two advantages over currently available technology. Firstly, due to the increased length of the device, there is significantly less chance of migration and embolism, as it cannot “roll” down the vessel. Upsizing, therefore, is less critical, and 20% above the vessel diameter seems adequate. Secondly, the three lobes of the plug provide for 6 planes of nitinol mesh interfering with flow, as opposed to the two planes of the single-lobed initial Amplatzer vascular plug. This results in rapid reduction of flow and thrombus formation. The disadvantage of this configuration is the requirement of at least 5 cm of vessel for plug deployment. Finally, the new delivery cable allows for delivery of the plug, even through very tortuous anatomy. Due to the tortuosity and aneurysmatic dilation of many coronary fistulae, in particular with relation to the true functional coronary artery, a long stretch of treatable vessel may not be easily approached. In cases such as this, due to the easily treated proximal segment distal enough from the true RCA continuation, the fistula could be approached from the arterial aspect, avoiding exploration of the fistula-right atrial junction and obviating the complexity of performing an arterio-venous loop. In conclusion, the novel Amplatzer Vascular Plug II allows for simple, safe and rapid closure of complex coronary cameral fistulae with appropriate anatomy.

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