Patent Ductus Arteriosus Associated with Aberrant Right Subclavian Artery: Two Cases, One Successful Interventional Closure of PDA
- Volume 23 - Issue 1 - January, 2011
- Posted on: 1/2/11
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ABSTRACT: Two children were sent to the catheterization laboratory for transcatheter closure of patent ductus arteriosus (PDA). During the intervention, cineangiogram revealed associated aberrant right subclavian artery (ARSA). Both patients had left-sided aortic arch. The first patient was sent to surgery after one unsuccessful attempt to close the PDA due to the proximity of the ARSA and also because of other concomitant cardiac lesions. We successfully treated the second patient by closing the PDA with a Nit-Occlud® PDA occlusion device (Pfm Medical, Carlsbad, California). Similar mirror cases of PDA closure with aberrant left subclavian artery and right aortic arch have been reported. Anatomic features, as well as the technique and management of the procedure, are discussed here.
Patent ductus arteriosus (PDA) is caused by the persistence of the posterior sixth aortic arch.1,3 As a unique pathology, it represents 9–12% of the total cases of congenital heart disease.1 Percutaneous closure using various occluders and coils is a well-established method.14–16 An aberrant origin of the right subclavian artery (ARSA) is an anomaly caused by the regression of the fourth aortic right arch between the right carotid and right subclavian arteries.2,4 The incidence has been estimated to be 0.5–0.8% in the general population.2,5 Associations with other cardiac anomalies have been described, such as Fallot’s syndrome, ventricular septal defect, PDA and coarctation of aorta. Higher rates are found in patients with Down syndrome and other cardiac anomalies.4
We report 2 cases of PDA in association with ARSA. One patient was successfully treated and percutaneous closure of PDA was performed.
Case Report. Patient #1. An 18-month-old female with Down syndrome and failure to gain weight was referred to our hospital. Examination revealed tachycardia and continuous murmur at the left infraclavicular region. Chest x-ray showed increased heart size and pulmonary markings. Echocardiogram reported moderate global cardiac dilation, a small perimembraneous ventricular septal defect (VSD) of 2–3 mm with left-to-right shunt and moderated tricuspid regurgitation, and PDA with left-to-right shunt and left-sided aortic arch.
She was sent to the cardiac catheterization laboratory for PDA closure in order to evaluate the behavior of perimembraneous VSD in the future. The patient was placed under general anesthesia. Right and left heart catheterizations were performed as usual. The intracardiac pressures revealed severe pulmonary hypertension. Pulmonary-to-systemic flow ratio was calculated to be 2.2:1. Cineangiogram data revealed an ARSA originating from the distal transverse aortic arch with a cephalic course from left to right (Figure 1). The PDA arose from the undersurface, very close to the take-off of the ARSA and connected to the pulmonary trunk (Figure 2). Anatomical features were similar to type-A ductus according to Toronto Hospital’s classification.17 Measurement results were 3.2 mm at the narrowest point, 9 mm at the aortic ampulla, and 8 mm in length. We selected a 7/6 mm Nit-Occlud® PDA occlusion device (Pfm Medical, Carlsbad, California). The size of the device was selected in order to avoid the origin of the ARSA. The system consists of: 1) a 5 French (Fr) introducer sheath with a marker ring at its distal tip; 2) a transportation sheath; and 3) a coil attached to a delivery system of flexible material with 2 marks and a disposable handle for release. The system was flushed as usual with heparinized solution. Through the venous approach, the introducer sheath was moved across the ductus using a 0.035 x 260 cm Wholey floppy wire (Mallinckrodt Inc., St. Louis, Missouri) and was positioned distally into the descending aorta. The transportation sheath and introducer sheath were connected. We advanced the coil through the two sheaths by pushing the delivery system until the first mark and both first and second cone of the coil were configured in the descending aorta. Fixing the delivery system to the transportation sheath, we pulled the entire system; no resistance was felt and the device was totally withdrawn to the pulmonary artery. We felt that a larger device could jeopardize the flow across the ARSA and the patient was referred to surgery due to concomitant cardiac lesions. Ductus ligation, VSD closure and tricuspid valvuloplasty were performed and the patient recovered uneventfully. The ARSA was left without treatment.
Patient #2. An 8-month-old, 10 kg female with Down syndrome and repeated episodes of obstructive and infectious pulmonary disease was referred to our hospital. A continuous murmur at the left infraclavicular region was found at physical examination. Chest x-ray revealed increased cardiothoracic ratio and pulmonary markings. Echo Doppler studies revealed PDA with left-to-right shunt, left atrium and ventricle enlargement, and left aortic arch. The patient was placed under general anesthesia in the cardiac catheterization laboratory. Cardiac catheterization data revealed pulmonary pressure 25/10 and estimated Qp/Qs of 1.9. Angiographic studies revealed left aortic arch with ARSA and PDA (Figure 3). PDA measurements were 3.6 mm in diameter at the narrowest point near the pulmonary trunk and 13–14 mm at the aortic ampulla.
PDA morphology corresponded to type A of the Toronto Hospital classification.17 The origin of the PDA at the descending aorta was 4 mm distal to the origin of the ARSA. An 11/6 Nit-Occlud® PDA occlusion device was chosen and deployed in the same fashion as the first case. The transportation sheath was positioned in the descending aorta through the PDA by the venous approach. The first and second cones of the device were configured directly in the origin of the aortic ampulla. After achieving a good position, we successfully released the device. A small passage of contrast to the pulmonary trunk was seen after angiographic control. No flow obstructions to the ARSA or the descending aorta were found by pull-back pressure registration or angiogram (Figure 4). Echocardiogram performed 24 hours post-procedure reported absence of PDA flow, and no gradient through the descending aorta or left pulmonary branch. She was discharged from the hospital without events 24 hours after the intervention.
Discussion. The first case was referred to surgery due to a failed attempt to close the PDA with a small device and for the reasons mentioned above (proximity of ARSA and concomitant cardiac lesions with probable need of surgical repair). In the second case, the ductus was successfully closed using a Nit-Occlud® PDA occlusion device.
ARSA is the most common arch anomaly, occurring in 0.5–0.8% of the general population.2,5 This condition is due to embryological regression of the fourth aortic right arch between the right carotid and right subclavian arteries.2,4 The incidence is higher in Down syndrome patients associated with other congenital heart disease.4 The diagnosis is made while imaging for another condition or at autopsy because most of the time no symptoms are referred, although dysphagia may appear in the young or adult patient (dysphagia lusoria).2,4–6,8,11,12
Left aortic arch with retroesophageal right subclavian artery and diverticulum of Kommerell is rare. A decrease in the caliber or the subclavian artery in this case indicates the presence of a ligament and a complete vascular ring.2,4 The existence of a right ductus or ligament in this case is a rare condition and also forms a vascular ring.2,4,11
In the past, surgical division was performed for treatment of this anomaly.7 Actually, many authors agree that in case surgical repair is needed for ARSA, anterograde flow must be established to avoid right arm ischemia or vertebral steal syndrome.8,11,12 Surgery could be challenging in adult patients with diverticulum of Kommerell.13
PDA plays an important role during fetal life. It constitutes a cardiac anomaly caused by the persistence of the posterior sixth aortic arch after birth, and connects the main pulmonary trunk with the descending aorta.1,3 Depending of the location of the aortic arch, it may be on the left, right and (rarely) bilateral.3 It represents 9–12% of total congenital heart diseases as a unique pathology.1 Higher rates are found in premature babies, those with congenital rubeolla, and births at high altitude.1,3 In some complex cardiac anomalies, the presence of PDA is essential for survival.1
Clinical manifestation depends on age of the patient, size of the defect, left-to-right shunt, pulmonary hypertension, etc. Echocardiographic and Doppler evaluations are essential in the management of PDA. A detailed description of aortic arch anomalies, vascular ring, and PDA exceeds the purpose of this communication and we encourage the reader to review the references.
Transcatheter closure is a standard of treatment for PDA. Different devices have been used for the last years with high rates of success. Anatomic features of the ductus must be considered when the closing device is selected.14–17
The Nit Occlud device used in these 2 cases was selected according to the anatomical features of the ductus, which corresponded to Type A of the angiographic classification presented by Kirchenko et al.17 This type is the most frequent presentation of PDA. The features of the Nit Occlud device, technique, delivery and deployment methods are published elsewhere.16
Two reports of mirror cases (right aortic arch, left aberrant subclavian artery and PDA) were found in the English literature.9,10 Percutaneous closures were performed with coils and procedures were successful in both reports, but in 1 patient the ductus was located on the left side with right aortic arch and aberrant left subclavian artery.9 PDA opposite to the aortic arch originating from a diverticulum of Kommerell and with aberrant subclavian artery forms a complete vascular ring. This anatomical feature may or not be symptomatic but it is more likely to become so.2,4,7,8,11 This is less frequent with left aortic arch and ARSA, because a diverticulum of Kommerell with a right ductus is rare.2,4 Although PDA closure seems to be a safe procedure in left aortic arch with ARSA, right ductus should not be closed and the patient referred to surgery as a vascular ring. Also, the proximity of the ARSA to the PDA (like the first case we reported) was considered to be an unusual intervention for the reasons mentioned above and we declined to close the PDA. We considered it important to communicate our experiences because there are few reports of PDA closure associated with ARSA.