Transcatheter Coil Embolization for Bilateral Coronary- Pulmonary Artery Fistula with Large Saccular Aneurysm: a case report

Whereas coronary artery fistulas (CAF) are the most frequent congenital anomalies influencing hemodynamic parameters of coronary arteries, bilateral coronary-pulmonary artery fistula (CPAF) complicated by a large saccular aneurysm is relatively rare. The optimal treatment of symptomatic patients with CPAF and aneurysm still remains a challenging problem and has been usually considered as an indication for cardiac surgery. The transcatheter coil embolization or covered stent for CPAF is a less invasive procedure and has recently been viewed as an alternative to surgical therapy. In this case, we describe a 61-year-old female with a congenital CPAF, originating from the ostium of the right coronary artery and mid segment LAD and draining into the pulmonary trunk and complicated by a large aneurysm presenting with typical angina pectoris. This patient underwent successful transcatheter closure of the right side fistula using a coil embolization technique, which resulted in improved symptoms and signs. Correspondence Author to: Wen-Hsiung Lin Division of Cardiology, Department of Internal Medicine, Mackay Memorial Hospital, Taitung, Taiwan No. 1, Lane 303, Chang-Sha Street, Taitung 950, Taiwan J Radiol Sci 2014; 39: 43-49 Coronary pulmonary artery fistula 44 J Radiol Sci June 2014 Vol.39 No.2 fatigue, chest tightness, angina pectoris, dyspnea, rupture or thrombosis of the fistula, arrhythmia, pulmonary hypertension, arterial aneurysm, congestive heart failure, infective endocarditis, sudden death and development of myocardial ischemia or infarction (presumably resulting from the coronary steal phenomenon). Frank congestive heart failure is a frequent complication, especially in patients above 40 years of age [9]. However, the optimal strategy to manage symptomatic patients still remains controversial due to the lack of longterm clinical follow-up. Conservative medical treatment remains the major treatment for most CPAF patients with limited symptoms/signs [1]. CASE REPORT A 61-year-old female had a history of regularly controlled hypertension and hyperlipidemia for 2 years. Her health examination of the coronary artery showed a calcium score of 193 indicating a possibly significant narrowing with at least moderate atherosclerotic plaque (90-95%). She suffered from aggravated effort angina and was referred to our cardiovascular clinic to survey coronary artery disease. Her treadmill revealed positive and echocardiography had no obvious regional wall motion abnormality. The patient was placed on a regimen of aspirin, bisoprolol and isosorbide mononitrate, but since her situation did not improve, coronary angiography was indicated for unstable angina. Coronary angiography revealed a few insignificant lesions and two macro-fistulas which originated from the proximal segment near the ostium of the RCA and branch of mid segment of LAD, complicated by a large saccular aneurysm (15 mm x 17 mm in diameter) and draining into the pulmonary trunk (Fig. 1). The right side fistula was larger than the RCA and left side fistula, and the patient’s typical ischemic symptoms were most likely caused by the coronary steal phenomenon secondary to the fistulas. After we discussed the therapeutic strategies with the patient and her family, they chose coil embolization of the right side fistula rather than surgical closure of the bilateral fistulas or cover stent. Before intervention therapy, the chest CT used to perform a detailed survey of the CPFA showed the coronary artery ostium in the normal position. An enlarged arterial fistula was found arising from the proximal RCA connected to a vascular pouch about 1.7cm in size in front of the pulmonary trunk. Another fistula was noted arising from the branches of the LAD to another vascular pouch above the previous one, with both of these vascular structures draining into the pulmonary trunk (Fig. 3a). Transcatheter closure was performed via the right femoral artery access with a 7 French (Fr) sheath, and the RCA ostium to the CPAF was engaged with a 7 Fr JR5 guiding catheter (Medtronic, USA), and a floppy guidewire (Runthrough NS®) was inserted into the aneurysm of the CPAF. We attempted to advance the wire to the pulmonary artery, but it failed to get into the distal small orifice of the large aneurysm. The delivery catheter, a 2.6 Fr x 150 cm Excelsior 1018 microcatheter guide (Boston Scientific, USA), was gently advanced under fluoroscopic guidance over a floppy wire directly to the aneurysm of the fistula in order to occlude the drainage orifice and minimize the risk of embolization. Because of the high resistance force due to the severe distortion of the fistula, the guiding catheter, microcatheter and wire was dislodged three times. The buddy wire technique to the RCA and fistula also failed. Fortunately, the deep seating technique successfully advanced a 5 Fr JR5 guiding catheter (Boston Scientific, USA) to the second curve with good support and the microcatheter was positioned in the aneurysm of the fistula. Two GDCs (Guglielmi detachable coils), 14mm x 30cm coil (Boston Scientific, USA) were first deployed within the aneurysm sac, to secure the distal fistula orifice, in order to prevent future distal coil migration (Fig. 2a, 2b). After delivery of the device, coronary angiography confirmed the partially successful occlusion of the fistula with less visible residual flow from the fistula. Another additional twenty microcoils (stainless steel MWCE® 18S-6/2-TORNADO; 6-2 mm) were deployed sequentially and completely obliterated the RCA fistula vessel (Fig. 2c, 2d). Following the above procedures, the coils were implanted so as to merge together forming a conglomeration. Coronary angiography was repeated to confirm the quality of the occlusion, and heparin (60 U per kg) was given during the procedure. There were no ECG changes noted that might suggest myocardial ischemia following the procedure; no procedural complication occurred and the patient was discharged on the following day. The patient subsequently reported that her earlier clinical symptoms had improved, and that her recovery continued uneventfully. After one year, the chest CT was followed up and revealed the status of the post embolization of the coronary CPFA. There was no obvious shunting flow from the right coronary artery, but there was still some shunting flow from the left coronary artery (Fig. 3b-3d). DISSCUSSION Most CAFs have been reported from studies on Caucasian people. The first report of Oriental CAF patients described incidence (0.4%), observed that 58% of CAFs originated from the left anterior descending artery and 29% from the right coronary artery, and noted that most CAFs (63%) drained to the pulmonary artery [10]. Most CAFs manifest as a single fistula and cases of multiple fistulas are generally rare. The morphologic features of CPAFs are different from CAFs. The origin of CPAFs was 29.4% in the left coronary artery, 11.8% in the right coronary artery and 58.8% in both coronary arteries; and 29.4% cases were associated with aneurysm. Fistulas were located primarily in the left Coronary pulmonary artery fistula 45 J Radiol Sci June 2014 Vol.39 No.2 anterolateral aspect of the pulmonary trunk (82.3%) and mostly the drainage site was the left lateral side of the pulmonary trunk (82.3%) [11]. Coronary-pulmonary artery fistulas may appear as isolated anomalies in most cases, or they are associated with diverse patterns of congenital heart diseases, such as left or right ventricular hypoplasia [12]. In acquired cases, they are associated with the complications developed after