Successful transcatheter closure of coronary artery fistula in a patient with anomalous aortic origin of the left main coronary artery from the right aortic sinus

Abstract

Transcatheter closure is an established method to treat coronary artery fistula (CAF). We present transcatheter closure in a 6-year-old girl with CAF and anomalous aortic origin of the left main coronary artery from the right aortic sinus. The CAF originated from the left coronary artery (LCA), coursed through the interventricular septum (intraseptal course) with prominent dilation, and drained into the right ventricular outflow tract. She underwent transcatheter closure and was in a stable condition at the 3-year follow-up with regression of the dilated portion of the intraseptal-type LCA. Hence, transcatheter closure of CAF is feasible in patients with anomalous origins of coronary arteries.

<Learning objective: This report describes the feasibility and safeness of transcatheter closure of a coronary artery fistula in a patient with an anomalous origin of a coronary artery. This is the first report to visualize the regression of the markedly dilated left coronary artery with an intraseptal course.>

Introduction

Congenital anomalies of coronary arteries are uncommon but can cause serious cardiac events including myocardial ischemia or sudden cardiac death. Coronary artery fistula (CAF) is an anomaly of coronary termination, with connections between the coronary artery and the cardiac chambers or any of the large vessels. CAFs are reported in 0.1 to 0.8% of patients undergoing angiography [1], [2]. Clinical symptoms of CAF depend on the amount of left-to-right shunt. Large shunt can lead to pulmonary hypertension, heart failure, myocardial ischemia, or myocardial infarction. Rupture or thromboembolism of CAF-associated arterial aneurysm may also occur [2].

Anomalous aortic origin of the left main coronary artery from the right aortic sinus (AAOLCA) is extremely rare, reported in 0.017 to 0.15% of patients undergoing angiography [1], [3], [4]. The risk of cardiac events in AAOLCA depends on its anatomical course, of which there are four: (1) anterior to the pulmonary artery, (2) posterior to the aorta, (3) through the intraventricular septum inferior to the pulmonary valve (intraseptal, intraconal, or intramyocardial course), or (4) in between the pulmonary artery and aorta superior to the pulmonary valve (interarterial course). The interarterial course carries the highest risk [5]. The reported risk of the intraseptal course varies from benign to malignant [4], [6]. In cases of CAF with AAOLCA, we should consider both risks.

CAF can be managed differently, depending on the morphology. Therapeutic options include surgical or transcatheter closure; recently, the latter is being increasingly used. However, aneurysm regression after intervention is unclear, especially in cases of intraseptal-type AAOLCA. We report our experience of successful transcatheter closure of CAF originating from the left coronary artery (LCA) with anomalous origin, draining into the right ventricular outflow tract (RVOT), using Amplatzer Vascular Plug II (AVP II; St. Jude Medical, Austin, TX, USA) and the angiographic changes to the aneurysm after closure.

Case report

A female neonate born at 41 gestational weeks presented with a cardiac murmur on day 6. She was referred to a pediatric cardiologist on day 10 and diagnosed with CAF. Echocardiography showed a markedly dilated LCA with continuous flow into the right ventricle (RV). She was clinically stable and did not show any signs of ischemia even when she was crying or being fed. At 2 years, she underwent her first cardiac catheterization. Angiography revealed a CAF originating from the LCA and draining into the RVOT. The LCA was dilated to 5.5 mm and development of collateral arteries from the right coronary artery (RCA) was observed. Hemodynamic and oximetry data demonstrated a pulmonary-to-systemic blood flow ratio (Qp/Qs) of 1.2 with normal pulmonary vascular resistance. No intervention was performed at this point. Second cardiac catheterization at 5 years of age revealed that the dilation of the aneurysm increased to 6.5 mm, while Qp/Qs was still 1.2. Antiplatelet therapy with aspirin was initiated, and the attending physician planned for CAF ligation at the age of around 10 years, when she would have gained enough weight to undergo surgery safely.

At 6 years of age, she was referred to our hospital at her family’s request. On physical examination, she had a grade 4/6 continuous murmur with a thrill along the left sternal border. Chest radiography and blood test results were unremarkable, except for slightly elevated brain natriuretic peptide levels (34.4 pg/ml). Electrocardiography showed sinus rhythm, normal axis and intervals, and no ST-segment or T-wave changes. Adenosine stress myocardial perfusion imaging showed no remarkable findings. Transthoracic echocardiography revealed a markedly dilated LCA originating from the right aortic sinus running through the outlet portion of the interventricular septum (intraseptal course), normal origin and dimensions of the RCA, and a fistulous tract originating in the aneurysm and draining into the RVOT (Fig. 1A). Diastolic reverse flow in the descending aorta was also seen. Color flow mapping showed continuous flow in the RVOT below the pulmonary valve. Left ventricle (LV) was dilated to 110% of the normal value and systolic function was preserved. Neither asynergy nor pulmonary hypertension was seen. Computed tomography (CT) angiography revealed the anatomy and course of the CAF, aneurysm, and intraseptal-type AAOLCA (Fig. 1B–E).

Fig. 1.

Echocardiogram and computed tomography (CT) angiogram. (A) Transthoracic echocardiogram shows an aneurysm of the left coronary artery (LCA) measuring 8.1 mm and originating from the right aortic sinus with an intraseptal course (arrow). CT angiogram. (B) Aneurysm of the LCA originating from the right aortic sinus (arrow). (C) Intraseptal course of the LCA (arrow) and coronary fistula (CAF) originating from the aneurysm and draining into the right ventricular outflow tract (RVOT). Three-dimensional reconstruction (D) Frontal image, (E) Cranial image.

Ao, aorta; LCX, left circumflex artery; RCA, right coronary artery; RCC, right coronary cusp.

Informed consent was obtained from the patient’s family for cardiac catheterization and CAF occlusion under general anesthesia. Hemodynamic and oximetry data revealed a Qp/Qs of 1.4 with normal pulmonary vascular resistance. LV volume was increased to 117% of the normal value. Selective LCA and right cusp angiography showed dilation of the LCA measuring 8.3 mm with contrast draining into the RVOT. The left anterior descending (LAD) and left circumflex (LCX) arteries originated in the proximal side of the CAF with two separate orifices. CAF was narrowest just before draining into the RVOT with a minimum lumen diameter of 3.4 mm (Fig. 2A–C). It was a large fistula with high blood flow. We assumed that CAF closure would require high embolization force; thus, we chose AVP Ⅱ for closure. The occlusion site was selected from the entry just after the origin of the normal coronary artery to its narrowest part. The size of AVP Ⅱ was selected to be 1.5 times the size of the minimum lumen diameter and larger than the maximum lumen diameter. Through a femoral approach, 6-Fr venous and 4-Fr arterial sheaths were placed. A 4-Fr JR2.5 catheter with a 0.025-inch angle-tipped guidewire (Terumo Corporation, Tokyo, Japan) was passed to the distal end of the CAF into the RV. To approach the CAF, we used a telescope technique using a 2.8-Fr micro-catheter with a 0.016-in angled and soft-tipped GT wire (Terumo Corporation) in a 4-Fr end-hole catheter deployed through a 6-Fr JR-shaped Vista Bride-tip guiding catheter (Cordis Corporation Bridgewater, NJ, USA). Using a 10 mm Amplatz gooseneck snare kit (Medtronic, Minneapolis, MN, USA) via the retrograde course, we created an arteriovenous loop for trackability of the 6-Fr guiding catheter, and the catheter tip was advanced into the CAF (Fig. 2D). After contrast test injection for determining catheter placement, the 6 mm AVP II was deployed.

Fig. 2.

Angiogram. (A) Frontal view shows markedly dilated left main coronary artery with contrast draining into right ventricular outflow tract (RVOT) and dominant right coronary artery (RCA). (B) Cranially angled right anterior oblique view shows aneurysm measuring 8.3 mm in maximum diameter, left anterior descending artery (LAD), and left circumflex artery (LCX) originating from the proximal side of the coronary fistula (CAF) measuring 3.4 mm in minimum diameter. (C) Caudally angled lateral view shows a tortuous CAF toward the anterior side. (D) Arteriovenous loop provided trackability for the 6-Fr guiding catheter, and the tip of the guiding catheter was advanced into the coronary fistula. (E, F) Post-procedural angiogram showing complete occlusion of coronary fistula with Amplatzer Vascular Plug II and improvement of LAD and LCX filling. (E) Cranially angled right anterior oblique view. (F) Caudally angled lateral view.

RCC, right coronary cusp.

Repeated angiography showed intact native LAD and LCX, and the device was positioned well. The device was released. Ten minutes after deployment, another angiography demonstrated successful complete occlusion of the CAF with improved native LAD and LCX perfusion (Fig. 2E,F). The postprocedural course was uneventful. There were no cardiac murmurs, continuous flow on echocardiography, and ST-segment or T-wave changes on the electrocardiogram. She was discharged 2 days post-procedure and prescribed aspirin and warfarin. Follow-up angiography after 1 and 2 years and CT after 1 year showed complete occlusion of the CAF and LAD and LCX perfusion. Developed collateral arteries from the RCA, and regression of the LCA aneurysm to 2.9 mm was also observed (Fig. 3). There was no sign of ischemia on treadmill and adenosine stress myocardial perfusion imaging. She is on single-antiplatelet therapy with aspirin and is being treated on an outpatient basis in a fairly stable state.

Fig. 3.

Angiogram. An angiogram after 2 years shows complete occlusion of the coronary fistula, regression of the left coronary artery (LCA) aneurysm, and dominant right coronary artery (RCA). (A) Frontal view of the RCA. (B) Frontal view of the LCA. (C) Cranially angled right anterior oblique view of the LCA.

Computed tomography angiogram. 3D reconstruction (D) Frontal image, (E) Cranial image.

LAD, left anterior descending artery; LCX, left circumflex artery.

Discussion

A 6-year-old girl underwent transcatheter closure of CAF with AVP II. In addition to an LCA aneurysm with a tortuous tract draining into the RVOT, the LCA originated from the right aortic sinus with an intraseptal course. After the procedure, the patient had no evidence of ischemia while LCA aneurysm regressed and is currently in an excellent condition.

Transcatheter closure is an effective therapeutic option for CAF in patients with intraseptal-type AAOLCA. Spontaneous closure of CAF is uncommon (1–2% of cases, including asymptomatic patients) [2], [7]. This patient needed closure of CAF due to dilated LV and progressive dilation of aneurysms [8]. The biggest concern in such cases is ischemia. In intraseptal-type AAOLCA, the coronary artery runs remotely from the sinus of Valsalva and is fixed within the intraventricular septum. Thus, therapeutic interventions such as reimplantation and unroofing are impossible [9]. Coronary artery bypass graft (CABG) surgery was considered but had safety concerns due to technical problems related to coronary artery abnormalities (tiny normal coronary artery and aneurysm) and risk of graft failure with bypass grafting in the presence of antegrade coronary blood flow, particularly in children. In this case, the clinical course, including ischemia of the LCA aneurysm with intraseptal-type AAOLCA after closure of CAF, was unpredictable. We assumed that adhesions may become problematic in additional CABG surgery after surgical ligation of CAF. We selected transcatheter closure as a primary strategy and CABG as the secondary strategy in case of ischemia. As our surgeon could perform CABG, we decided on catheter intervention at this time. To our knowledge, this is the first report that describes transcatheter closure of CAF in a patient with intraseptal-type AAOLCA. In this patient, complete occlusion of the CAF and uneventful postprocedural course suggest that transcatheter closure could also be a therapeutic option for CAF combined with other coronary anomalies.

After transcatheter closure of CAF, the dilated LCA with intraseptal course began to regress without any signs of ischemia. This was a different course from that described in a previous report [10], wherein a significantly large distal-type CAF, with a fistula arising from a major distal coronary artery, was reported to have a risk of coronary events due to thrombosis and discrete intimal stenosis. There is no report on regression of aneurysm with intraseptal-type AAOLCA; therefore, the relationship between aneurysm normalization and the intraseptal course was unclear. There is no established treatment for this rare combined disease; hence, we are maintaining close observation and antiplatelet therapy in accordance with the treatment for Kawasaki disease.

In conclusion, transcatheter closure could be a feasible therapeutic option for CAF combined with anomalous origins of coronary arteries, such as intraseptal-type AAOLCA. Further reports are required to better understand the outcome of specific aneurysms in CAF.

Conflict of interest

None.