Absent left main coronary artery in a case of pulmonary atresia-intact ventricular septum and right ventricle-dependent coronary circulation

Right ventricle-dependent coronary circulation coexisting with left main coronary atresia in the setting of pulmonary atresia-intact ventricular septum is rare. In the case described, the left coronary artery (LCA) origin from the aorta could not be found on conventional angiography or cardiac magnetic resonance imaging. During surgery, multiple LCA branches originating from the finger-like continuum of the primitive right ventricular sinusoidal network were observed. A Damus–Kaye–Stansel anastomosis and an aortopulmonary shunt operation were performed. Shunt takedown and a bidirectional Glenn anastomosis followed at 3 months of age. At 18 months follow-up, the child is thriving with stable hemodynamics and a saturation of 85%. Awareness about this rare coronary artery anomaly is necessary to prevent catastrophic consequences. The challenges, complications, and lessons learned while treating this rare variant are discussed.

Keywords: Coronary anomaly, Damus–Kaye–Stansel, shunt, univentricular heart

How to cite this article:
Krokovay A, Knirsch W, Kelly-Geyer J, Cesnjevar R, Dave H. Absent left main coronary artery in a case of pulmonary atresia-intact ventricular septum and right ventricle-dependent coronary circulation. Ann Pediatr Card 2022;15:425-8
How to cite this URL:
Krokovay A, Knirsch W, Kelly-Geyer J, Cesnjevar R, Dave H. Absent left main coronary artery in a case of pulmonary atresia-intact ventricular septum and right ventricle-dependent coronary circulation. Ann Pediatr Card [serial online] 2022 [cited 2023 Jan 7];15:425-8. Available from: https://www.annalspc.com/text.asp?2022/15/4/425/367295

Introduction

Clinical presentation

A newborn child (birth weight 3.1 kg), with a diagnosis of pulmonary atresia, (hypoplastic right ventricle [RV]) and intact ventricular septum (PA-IVS) was referred to our unit. Left ventricular function and electrocardiogram (ECG) were normal. Echocardiography led to suspicion of a single (normal-sized) coronary origin from the anterior sinus. The anatomy fit the diagnosis of pulmonary atresia-intact septum, with the hypoplastic pulmonary trunk perfused retrogradely through the duct. A coronary arising from the hypoplastic pulmonary trunk was suspected. Previous experience of a similar unknown entity[1] involving the complete absence of coronary perfusion from the aortic root, leading to a lethal outcome, had sensitized us about this dreadful anomaly. Angiocardiography confirmed the presence of a single right coronary artery (RCA) [Figure 1]a and [Figure 1]b, while the left coronary artery (LCA) origin could not be determined. A cardiac magnetic resonance imaging did not help to ascertain the LCA origin.

Figure 1: (a and b) Preoperative aortic root shoot contrasting a single RCA, (c) Aortic root angiogram after DKS operation demonstrating LAD and anterior ventricular branches, (d) Coiling of the RVOT leading to LAD thrombosis, (e) Pre-Glenn angiogram showing well perfused. RCA: Right coronary artery, DKS: Damus–Kaye–Stansel, LAD: Left anterior descending, RVOT: Right ventricular outflow tract

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Surgical exploration

Surgical exploration with a goal of univentricular palliation was undertaken. A finger-like tortuous hypoplastic RV sinusoidal network giving rise to the left anterior descending (LAD), and anterior ventricular branches was observed [Figure 2]a. A separate left circumflex artery was seen arising from the hypoplastic pulmonary trunk [Figure 2b]. An extensive network of epicardial collateral network was visible on the left ventricular (LV) free wall [Figure 2c]. Aortopulmonary groove was carefully dissected to prevent inadvertent damage to a coronary artery arising anywhere from the pulmonary trunk.

Figure 2: (a) The primitive RV giving rise to LAD and multiple LV branches, (b) Left circumflex coronary artery arising from left-ward sinus of the hypoplastic PA, (c) Extensive epicardial collateralization between R and L coronary systems, (d) A single RCA ostium visible arising from the aortic sinus. LAD: Left anterior descending, RV: Right ventricular, LV: Left ventricular, PA: Pulmonary atresia, RCA: Right coronary artery, R & L Right and left

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Cardiopulmonary bypass and cardioplegia

Cardiopulmonary bypass (CPB), myocardial protection, and surgical technique each required to be tailor-made for this unusual anatomy. Conventional CPB was established. The perfusate was not cooled and the heart not emptied initially to avoid ischemia due to unloading of the heart. The ECG did not show any changes, nor was the contractility undermined.[1] Antegrade cold blood cardioplegia was administered in the aortic root since the pulmonary trunk was very small. Immediate effective cardiac standstill was achieved. Had the cardioplegic arrest not been effective, cardioplegia delivery into the pulmonary root would have been administered.

Surgical technique

Transection of the aortic and pulmonary roots was performed. Only RCA ostium arising normally was identified [Figure 2d]. The pulmonary root was small; a single ostium continuing into the tortuous finger-like RV was observed. Direct cardioplegia into this opening showed perfusion of the left coronary system. Damus–Kaye–Stansel (DKS) anastomosis of the dominant aortic and the hypoplastic pulmonary root was performed using double-barrel technique. Atrial septectomy and a 3 mm central aortopulmonary shunt were constructed.

Postoperative recovery

The child recovered well. A diagnostic angiography few weeks postoperatively showed a well-perfused R and L coronary system [Figure 1c]. Coiling of the RV outflow tract was undertaken, to prevent a possible coronary steal (diastolic backflow through the hypoplastic RV – small ventricular septal defect – LV). This led to the proximal progression of thrombus, occluding the LAD [Figure 1d]. The child was shifted to the operating room, coil was removed [Figure 1e]. The child recovered well, ECG and myocardial function were normalized. A bidirectional Glenn was successfully performed at 3 months of age. The left pulmonary artery needed a stent postoperatively. The child was discharged home 2 weeks post-Glenn operation. She is thriving well at 1.5-year follow-up, with a saturation of 85% on room air.

Comment

RV-dependent exclusive perfusion of the left coronary system is rare. Anomalous left coronary origin from the pulmonary arteries has been reported.[2],[3] We came across a rare coronary anomaly[1] when a univentricular heart suddenly became pale and showed severe myocardial dysfunction after instituting CPB and ligation of the patent ductus arteriosus (PDA). This child was later found to have a complete absence of coronaries originating from the aorta. An autopsy showed coronary artery originating from the hypoplastic RV. The child did not survive.[1] This led us to a high index of caution for such a rare coronary artery malformation. Sakurai et al.[4] have reported a successful treatment of a child with PA-IVS having bilateral coronary ostial atresia.

Once an aortic coronary origin is missing, the absent coronary is likely to originate from the hypoplastic RV or the PA branches. Other groups have reported selective coronary origin from the pulmonary arteries in association with various cardiac defects including hypoplastic left heart syndrome.[3],[4],[5] Although anatomically different than our index case, the similarity confines to coronary origin from the right heart architecture. On echocardiographic suspicion of a coronary anomaly, angiography is the obvious modality of choice. If coronary origin cannot be ascertained, RV-dependent coronary perfusion should be anticipated. A cross-sectional imaging may be considered as a supplementary diagnostic modality. Intraoperatively, one should be careful while dissecting the pulmonary side branches to avoid inadvertent injury to an anomalous coronary artery. A small coronary vessel may be mistaken for lymphatics or a nerve from the cardiac plexus. Every such vessel needs to be followed and identified before division. Just unloading the heart with normal CPB, hypothermia, and PDA ligation, may lead to myocardial ischemia with disastrous consequences. Cardioplegia application in both aortic and pulmonary roots may be necessary. Retrograde cardioplegia application in the coronary sinus may also be considered. Once good myocardial protection is established by effective cardioplegia, a DKS anastomosis with shunt can be performed. The only difference here being that the pulmonary root is the less dominant of the two. The complication we encountered, following coiling to prevent the diastolic runoff through a small VSD was a misjudgment.[6] It at all, such an intervention may at best be postponed to a time when the child is bigger.

Consent

A general consent from the parents was undertaken. The Cantonal Ethics Committee waives the need for approval in such case reports.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that name and initials of their child will not be published and due efforts will be made to conceal their child's identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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4.Sakurai H, Sakurai T, Ohashi N, Nishikawa H. Aortic to right ventricular shunt for pulmonary atresia with intact ventricular septum and bilateral coronary ostial atresia. J Thorac Cardiovasc Surg 2018;156:e17-20.

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