Prenatal diagnosis of a coronary-to-pulmonary artery fistula in a fetus with pulmonary atresia and ventricular septal defect
- Ryo Ishii ,
- Hidekazu Ishida ,
- Jun Narita and
- Keiichi Ozono
- Department of Pediatrics, School of Medicine Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
- Correspondence to Dr Ryo Ishii; i-ryo@ped.med.osaka-u.ac.jp
Abstract
Pulmonary atresia and ventricular septal defect (PA/VSD) demonstrate a wide variety of pulmonary and coronary artery abnormalities; additionally, coronary-to-pulmonary artery fistula (CPAF) is a rare manifestation of PA/VSD and is seldom detected during pregnancy. In this report, we present a case of prenatal diagnosis of CPAF in PA/VSD and impactful images in a neonate, which were obtained using fetal echocardiography and postnatal electrocardiography-gated 320-row CT. Prenatal diagnosis of CPAF can facilitate the provision of better therapeutic strategies after birth.
Background
Patients with pulmonary atresia and ventricular septal defect (PA/VSD) show a variety of pulmonary and coronary artery anatomies.1 Additionally, a coronary-to-pulmonary artery fistula (CPAF) occurs in 1.3%–10% of patients with PA/VSD.2 Various types of CPAF associated with PA/VSD have been reported; however, to the best of our knowledge, there is no report of prenatal diagnosis of CPAF with PA/VSD, probably due to the rarity of the condition and the technical difficulty of the imaging method. In this report, we demonstrated clear images of CPAF associated with PA/VSD using fetal echocardiography and confirmed the exact morphology of CPAF in a neonate using electrocardiography (ECG)-gated 320-row CT in neonate.
Case presentation
The patient’s mother, gravida 1, para 0, was referred to our hospital after being suspected of a fetal cardiac malformation detected on a fetal screening at 24 weeks of gestation. She was in good health, without any maternal complications or high-risk factors. There was no family history of heart disease. Fetal echocardiography (Voluson E8; GE Healthcare) revealed a subaortic VSD (4 mm in diameter), with over-riding aorta (over-riding ratio of 40%–50%) on the five-chamber view, pulmonary valve atresia and major aortopulmonary collateral artery (MAPCA) arising from the descending aorta (dAo) on the three-vessel view and right ventricular outflow tract view at 28 weeks of gestation (figure 1, videos 1A,B). Follow-up fetal echocardiography detected a coronary-to-pulmonary artery fistula communicating to the central pulmonary artery (PA) without ductus arteriosus at 35 weeks of gestation (figure 2, video 2). According to these results, we diagnosed PA/VSD and CPAF and talked about the possible therapeutic strategies after birth and the potential risk of coronary steal to the parents. Finally, a male infant was delivered at 41 weeks of gestation. On physical examination, the neonate weighed 3.7 kg with oxygen saturation of 80%–90%, respiratory rate around 50 breaths/min, heart rate around 130 beats/min and no extracardiac malformations. The patient had tachypnea (100/min) and required nasal high-flow therapy and nitrogen inhalation therapy from 11 days of age until the operation. No abnormal electrocardiographic findings were observed. His chromosomal test showed normal after birth.
(A) Two-dimensional image of fetal echocardiography showing the five-chamber view. The perimembranous VSD and aAo over-riding interventricular septum is seen. (B) Two-dimensional and colour Doppler image of fetal echocardiography showing the three vessels view. The stenotic pulmonary artery is seen on normal position, but pulmonary valve and pulmonary forward blood flow from the right ventricle is not detected. (C) Two-dimensional and colour Doppler image of fetal echocardiography showing RV outflow view. MAPCA originates from dAo connects PA without DA. aAo, ascending aorta; DA, ductus arteriosus; dAo, descending aorta; LV, left ventricle; MAPCA, major aortopulmonary collateral artery; PA, pulmonary artery; RV, right ventricle; VSD, ventricular septum defect.
Disclaimer: this video summarises a scientific article published by BMJ Publishing Group Limited (BMJ). The content of this video has not been peer-reviewed and does not constitute medical advice. Any opinions expressed are solely those of the contributors. Viewers should be aware that professionals in the field may have different opinions. BMJ does not endorse any opinions expressed or recommendations discussed. Viewers should not use the content of the video as the basis for any medical treatment. BMJ disclaims all liability and responsibility arising from any reliance placed on the content.
Disclaimer: this video summarises a scientific article published by BMJ Publishing Group Limited (BMJ). The content of this video has not been peer-reviewed and does not constitute medical advice. Any opinions expressed are solely those of the contributors. Viewers should be aware that professionals in the field may have different opinions. BMJ does not endorse any opinions expressed or recommendations discussed. Viewers should not use the content of the video as the basis for any medical treatment. BMJ disclaims all liability and responsibility arising from any reliance placed on the content.
(A) Two-dimensional image of fetal echocardiography showing three vessels, tracheal view. A CPAF originates from aAo and communicates with mPA. (B) Colour Doppler image of fetal echocardiography shows a CPAF supplies blood flow toward mPA. (C) Schema of the fetal echocardiography, which was created by RI (corresponding author), is shown in Figure2A and 2B. aAo, ascending aorta; CPAF, coronary-to-pulmonary artery fistula; LPA, left pulmonary artery; mPA, main pulmonary artery; RPA, right pulmonary artery.
Disclaimer: this video summarises a scientific article published by BMJ Publishing Group Limited (BMJ). The content of this video has not been peer-reviewed and does not constitute medical advice. Any opinions expressed are solely those of the contributors. Viewers should be aware that professionals in the field may have different opinions. BMJ does not endorse any opinions expressed or recommendations discussed. Viewers should not use the content of the video as the basis for any medical treatment. BMJ disclaims all liability and responsibility arising from any reliance placed on the content.
Investigations
On transthoracic echocardiography (TTE) performed immediately after birth, we observed findings consistent with previous fetal echocardiography. The notable finding was that the right coronary artery (RCA) and left coronary artery originated from normal valsalva sinuses, with the CPAF arising from the proximal RCA connected to the central PA. To observe the appearance of CPAF in detail immediately after birth, cardiac catheterisation on day 0 and ECG-gated 320-row CT (Aquilion ONE GENESIS Edition; Toshiba Medical Systems) on day 3 were performed respectively, and the images of CPAF were consistent with fetal echocardiography findings. CPAF originating from the proximal RCA and the right ventricular branch was connected to the central PA. Two MAPCAs derived from the dAo supplied blood to the bilateral lung lobes, indicating a dual supply of pulmonary blood from the central PA and MAPCAs (figure 3, video 3).
(A) Aortography shows CPAF originates from RCA and subsequently is connected to the mPA. (B) Electrocardiogram (ECG)-gated 320-row CT angiography (CTA) shows the RCA and LCA originating from normal valsalva sinuses. (C) ECG-gated 320-row CTA especially shows the positional relationship of RCA and CPAF. RCA and LCA originate from the normal valsalva sinuses. CPAF originates from the RCA and subsequently is connected to the mPA. The central PA and two MAPCAs supply blood to the same lung field. aAo, ascending aorta; CPAF, coronary-to-pulmonary artery fistula; dAo, descending aorta; LCA, left coronary artery; LPA, left pulmonary artery; MAPCA, major aortopulmonary collateral artery; MPA, main pulmonary artery, RCA, right coronary artery; RPA, right pulmonary artery; RVB, right ventricular branch.
Disclaimer: this video summarises a scientific article published by BMJ Publishing Group Limited (BMJ). The content of this video has not been peer-reviewed and does not constitute medical advice. Any opinions expressed are solely those of the contributors. Viewers should be aware that professionals in the field may have different opinions. BMJ does not endorse any opinions expressed or recommendations discussed. Viewers should not use the content of the video as the basis for any medical treatment. BMJ disclaims all liability and responsibility arising from any reliance placed on the content.
Differential diagnosis
In the case of atretic right ventricular outflow and pulmonary annulus detected using fetal echocardiography or TTE, CPAF with PA/VSD and truncus arteriosus must be considered as differential diagnoses. They are the spectrum of congenital anomalies that result from failed septation of the embryonic truncus arteriosus or conotruncus. In our case, TTE showed that the aortic valve was a normal tricuspid valve with no regurgitation. Moreover, intraoperative findings showed that the wall of the vessel communicating the RCA to the central PA was thinner and had a different colour than the that of the pulmonary trunk. Therefore, we identified this vessel as CPAF (figure 4).
The intraoperative view shows the pulmonary artery trunk originates from the RCA, and the vascular wall of CPAF, which seems to be thinner than that of PA, and likely to be white. aAo, ascending aorta; CPAF, coronary-to-pulmonary artery fistula; LCA, left coronary artery; LPA, left pulmonary artery; MPA, main pulmonary artery; RCA, right coronary artery; RPA, right pulmonary artery; RVB, right ventricular branch.
Treatment
We performed a central shunt operation (left innominate artery to central PA) using a 3.5 mm Gore-Tex graft, division of CPAF and ligation of MAPCAs at 16 days after birth (figure 4). Thereafter, palliative right ventricular outflow tract reconstruction (RVOTR) using a 12 mm Gore-Tex conduit with tricuspid valve was performed at 5 months of age, and intracardiac repair with RVOTR using a 16 mm Gore-Tex conduit at 21 months of age.
Outcome and follow-up
Cardiac echocardiography and catheterisation showed good left and right ventricular function without pulmonary hypertension at 33 months of age. The patient demonstrated good growth and neurological development and showed no complications at 36 months of age.
Discussion
To the best of our knowledge, this is the first case of detection of CPAF with PA/VSD using fetal echocardiography. Previous reports demonstrated various types of CPAF with PA/VSD, which were diagnosed after birth.3 Our case presents with the CPAF originating from proximal RCA connected to the central PA. We present the ECG-gated CT images, which confirmed the accuracy of prenatal fetal echocardiography and provided much information that would be useful for surgical treatment. Currently, the evaluation of coronary and PA anomalies is essential for surgical planning in patients with PA/VSD. Therefore, high-resolution images of fetal echocardiography and CT play pivotal roles in strategising therapy after birth. Fetal MRI might improve diagnostic accuracy of the prenatal imaging and the pregnancy management. But fetal MRI might be limited in the evaluation of the congenital heart disease because of small size of the heart and rapid heart rate. On the other hand, fetal echocardiography might be useful to evaluate both anatomy and function of the heart.4 Because of the rarity of coronary artery anomalies with congenital heart disease, it is difficult to prenatally diagnose CPAF by fetal echocardiography.5 Reports of CPAF with PA/VSD in the fetus are unavailable. It is challenging for sonographers to detect CPAF. The CPAF might remain unnoticed if its blood flow is too small or with low velocity during the fetal period. In our case, colour Doppler flow imaging could detect a high-velocity flow and dilated blood flow of CPAF toward main PA; therefore, we could diagnose CPAF accurately in the fetus. Previous studies reported CPAF with PA/VSD was effectively diagnosed by cardiac catheterisation in the postnatal heart.3 Cardiac catheterisation is a standard for evaluating coronary arteries with congenital heart disease, but it is an invasive procedure in infants. Previous studies in younger children with lower body weights showed lower resolution images of the coronary arteries by CT because patients were scanned using a prospective ECG-gated target CTA volume during one cardiac cycle.6 However, recent CT images were effectively reconstructed, which enabled the coronary assessment, after data from all cardiac phases were obtained with retrospective ECG-gated scanning. Therefore, CT, which is less invasive than catheterisation, can be used to identify coronary artery anatomy in neonates compared with a higher diagnostic accuracy than TTE. Furthermore, it not only provides the origin and course of the coronary arteries but also their relationships with the surrounding cardiovascular anatomy.7 In our case, retrospective scanning by a three-cardiac cycle was performed to visualise the relationship between the coronary artery, CPAF and main PA at the best motion-free phase, despite the low body weight. Some reports of CPAF with PA/VSD demonstrated that pulmonary vascular obstructive change might occur as early as in infancy before surgical palliation and might lead to bad prognosis.3 Therefore, it is valuable that prenatal diagnosis of CPAF with PA/VSD can help to decide the timing of early surgical intervention to properly control the pulmonary blood flow after birth. In conclusion, careful fetal echocardiography can demonstrate CPAF and the ECG-gated 320-row CT can be a powerful and less-invasive diagnostic modality to make a definitive diagnosis. The accuracy of prenatal diagnosis using fetal echocardiography benefits perinatal counselling and decision-making during planning of therapeutic strategy after birth.
Patient’s perspective
I am the patient’s mother. I would like to talk about my feelings before and after my son’s birth, because my son is still too young to talk about his own feelings. I was very upset when I heard from my obstetrician during a prenatal check-up that my baby might have a congenital heart disease. In addition, I was even more anxious when, after undergoing a fetal echocardiogram at the specialty hospital, I learnt my baby’s heart disease was a very rare one. However, I gradually became more informed of the nature of my baby’s heart disease as I underwent repeated fetal echocardiography. I remember being very relieved when the doctor gave me an easy-to-understand, thorough explanation of the results of the tests as well as the proposed treatments for my baby antenatally. After my son’s birth, the examinations and treatments went as planned and as explained before the birth. Fortunately, all the step-by-step cardiac surgeries were successful and my son is now doing well with us. Our family feels so happy that we were able to get the correct diagnosis prenatally and have an effective treatment done. We hope that this case report will be visible to many people and will be useful to medical staff and patients or family who are in the same situation as we were.
Learning points
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It is important to detect the source of pulmonary blood flow by fetal echocardiography in the case of pulmonary atresia without patent ductus arteriosus in order to determine therapeutic strategy after birth.
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It is important to observe the characteristics of aortic valve, the origin of the common pulmonary trunk and its branches by fetal echocardiography to establish a correct differential diagnosis between truncus arteriosus and coronary-to-pulmonary artery fistula (CPAF) with pulmonary atresia and ventricular septal defect (PA/VSD).
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The electrocardiography-gated 320-row CT can be a powerful and less-invasive diagnostic modality to make a definitive diagnosis of CPAF.
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It is valuable that prenatal diagnosis of CPAF with PA/VSD can help to decide the timing of early surgical intervention to properly control the pulmonary blood flow after birth.
Ethics statements
Patient consent for publication
Footnotes
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Contributors RI contributed to research, writing and editing . HI, JN and KO contributed to overall guidance, direction and editing. All authors read, edited and approved the final document prior to submission.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.
References
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