Abstract
During initial repair of supracardiac total anomalous pulmonary venous connection (TAPVC), the vertical vein (VV) is sometimes left patent (not ligated or divided) in the hope that this strategy may reduce the likelihood or severity of postoperative pulmonary hypertensive crises. We report a case of a 35-year-old pregnant patient with previously repaired supracardiac TAPVC who presented with atrial arrhythmia and right heart dilation. A cardiac magnetic resonance imaging study confirmed the diagnosis of patency of the vertical vein and right heart dilation. The VV was occluded with a catheter-delivered vascular occlusion device through a percutaneous approach, resulting in resolution of right heart dilation and arrhythmia. This case highlights the role of cross-sectional imaging as an adjunct to echocardiography in adults with repaired congenital heart disease.
Keywords
Introduction
Supracardiac total anomalous pulmonary venous connection (TAPVC) is a rare congenital heart defect that requires surgical repair during infancy. Surgical repair includes anastomosis of the pulmonary venous confluence to the back wall of the left atrium and ligation of the vertical vein (VV). An important potential complication of this repair is pulmonary venous obstruction, which typically occurs post-operatively or during early childhood. Patients who survive into adulthood usually have a life span that is similar to the general population. 1 Ligation of the VV at the time of TAPVC repair in patients whose initial presentation includes an element of obstructed pulmonary venous return may lead to right ventricular dysfunction, pulmonary hypertension, and increased risk of sudden death. 2 Leaving the VV patent during TAPVC repair may improve postoperative outcomes and decrease mortality 3 by decompressing the pulmonary veins in patients with downstream obstruction or noncompliant left atrium, and promoting improved cardiac output. 4 Hence, in some cases, the VV is left unligated during the initial repair to prevent pulmonary hypertensive crises. 4 The unligated VV with a hemodynamically significant left-to-right shunt can be closed successfully at a later time with a percutaneous device. 5 In a small series of five patients, the gradual tightening of the unligated VV using a percutaneous approach during the first 24 to 96 hours after the surgery has been reported to be effective in maintaining stable hemodynamics postoperatively with the gradual elimination of the shunt as the patient tolerates. 6 We report our experience in a patient with repaired TAPVC and patent VV who presented with atrial arrhythmia and right heart dilation during pregnancy. It is likely that the atrial arrhythmia was related to right heart volume overload secondary to the left-to-right shunting via the VV, in combination with the physiologic changes during pregnancy such as an increase in plasma volume and cardiac output. Findings of right heart dilation in an adult congenital heart disease patient on routine echocardiography may be subtle, and presence of a patent VV may possibly be missed.
Case
A 35-year-old pregnant female, with a history of supracardiac TAPVC repaired in the neonatal period, was referred to our adult congenital heart center at 27 weeks of gestation for nonsustained atrial arrhythmia. The echocardiogram showed mild dilatation of the right atrium and the right ventricle. Knowing the patient’s anatomy and history of previous surgical repair, a source of left-to-right shunt at the atrial level. including the possibility of a patent VV, was suspected but could not be demonstrated due to poor echocardiographic windows. There had been no history of arrhythmia before this pregnancy. The patient was otherwise asymptomatic, and after discussing the risks and benefits, the patient opted to not start any medications, out of concern for the fetus. Review of the operative note revealed no comment about ligating the VV, and hence, a decision was made to obtain a cardiac magnetic resonance imaging study after pregnancy and delivery, keeping in mind the safety of the fetus and use of a contrast agent such as gadolinium to enhance the venous system during magnetic resonance angiography. Pregnancy itself could be contributing to the right heart dilation, and hence, a waiting period of six to eight weeks was selected. During labor, while being monitored with telemetry, the patient was noted to have frequent episodes of atrial arrhythmia, and she was started on a β-blocker. Cardiac magnetic resonance imaging (MRI) was performed two months after delivery. It confirmed the presence of a large, tortuous VV draining into the innominate vein, along with dilatation of the right ventricle. The estimated ratio of pulmonary blood flow to systemic blood flow (Qp:Qs) was 1.4:1 (Figure 1 and Supplemental Video). The pulmonary venous return to the left atrium was unobstructed. At this point, the patient underwent cardiac catheterization for a hemodynamic assessment and possible device occlusion of the VV. In the catheterization laboratory, the Qp:Qs ratio was 2:1 with normal pulmonary artery pressures (mean 14 mm Hg). Test occlusion of the VV showed no increase in the pulmonary artery or left atrial pressures, indicating that there was no downstream obstruction and VV was not serving to decompress the left atrium or the pulmonary veins, and it could be occluded safely. Angiogram demonstrated mild narrowing of the large VV as it coursed between the proximal descending aorta, left pulmonary artery, and left bronchus (Figure 2A). This is a common site for the obstruction in critically ill infants with supracardiac TAPVC. The diameter of the VV where it joined the left innominate vein was 15 mm. An 18-mm AMPLATZER™ vascular plug II (St Jude Medical Inc, Minnesota) was used to occlude the VV. The device was positioned in the VV above the level of the left pulmonary artery and the left bronchus, to avoid compression or erosion into the adjacent structures (Figure 2B). At three-month follow up, β-blocker was discontinued, and at six-month follow-up, the patient remained asymptomatic. Follow-up Holter monitoring showed no arrhythmia and the follow-up cardiac MRI and echocardiogram showed normalization of the right-sided chambers and complete occlusion of the VV.
Magnetic resonance angiogram (MRA) in a coronal plane showing the vertical vein draining into the left innominate vein.
A, A large vertical vein drains into the left innominate vein. The vertical vein is stenosed (*) as it courses between the left pulmonary artery, the left bronchus, and the aorta. B, The vertical vein is occluded with an AMPLATZER™ vascular plug II, placed above the narrowing so that pressure from the device is not exerted on the surrounding structures. SVC indicates superior vena cava.
Conclusion
Our case highlights the fact that cross-sectional imaging such as cardiac MRI with angiography serves as a useful adjunct to transthoracic echocardiography in the evaluation of posterior structures such as VV and other vessels in the superior mediastinum, especially in adult congenital heart disease patients with poor acoustic windows. Cardiac MRI has an advantage over computed tomography in avoiding radiation and additionally allowing measurement of the right ventricular volume and the ratio of pulmonary blood flow to systemic blood flow. Percutaneous device closure of the VV after confirmation of unobstructed pulmonary venous return to the left atrium is a safe and effective approach in patients with right-sided chamber enlargement. We know that in patients with repaired TAPVC, the VV may be patent in up to 60% of them 7 and ongoing left-to-right shunt may increase the risk of pulmonary vascular disease. Hence, it is essential for clinicians to know whether the vertical vein (VV) was ligated or left patent at the time of surgery.
Footnotes
Authors’ Note
The patient has granted consent for submission and publication of the case report.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
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References
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