Crossed Pulmonary Arteries with Double Aortic Arch

Crossed Pulmonary arteries with Double Aortic Arch:

A rare Association

Abstract

Crossed pulmonary arteries are a rare benign congenital anomalies. In this anomaly, the left pulmonary artery originates from the pulmonary trunk superiorly and to the right of the origin of the right pulmonary artery. Both pulmonary arteries cross each other on their course to each respective lung, thus forming a crisscross pattern.This rare pathology is generally accompanied by other congenital heart defects and certain genetic problems. We report on echocardiography an infant with crossed pulmonary arteries and a complete vascular ring formed by double aortic arch, which was confirmed by computed tomography angiography.

Keywordscrossed pulmonary arteries, Double aortic arch, vascular ring, computed tomography angiograhy.

Case Report

An 8-month-old male infant was referred to our department for cardiac evaluation due to recurrent wheezy chest and inspiratory stridor. The patient had normal vital signs, normal laboratory workup and was hemodynamically stable. He is a product of full term, Caesarian section delivery due to obstructed labor and weak contractility, birth weight of 3.2 kg. The antenatal and family histories were not contributory. Recurrent hospitalization due to wheezy chest and strider. He has normal growth, his present body weight is 8 kg. No dysmorphic features. Femoral pulses were well palpable. Auscultation of the heart revealed grade II systolic ejection murmur over the 2 intercostal space at the left sternal border. Electrocardiography was normal.Transthoracic echocardiography showed no intracardiac defects. The pulmonary valve was normal, the bifurcation of pulmonary arteries was not visualized, but the left pulmonary artery (LPA) originatedfrom the right portion of the main pulmonary artery (MPA) superior to the right pulmonary artery(RPA) with mild ostial stenosis,while the RPA originated from the left portion of MPA, inferior to the LPA (FIG1-2).Double aortic arch was also detected. Computed tomography angiogram (CTA) confirmed the crossed pulmonary arteries with double aortic arch forming a complete vascular ring(FIG 3-4). The patient was sent for surgical correction.

Discussion

Crossed pulmonary arteries, also called anomalous origin of the pulmonary arteries from the pulmonary trunk or crisscross pulmonary arteries, is a rare abnormality in which the LPA originates from the pulmonary trunk to the right and usually above the origin of the RPA1.Both pulmonary arteries crisscross along their course to each respective lung. The etiology of crossed pulmonary arteries is unknown, but it is suggested that the phenomenon may result from faulty differential growth within the pulmonary trunk causing the two branches to lose normal relationships and to cross over each other. Few cases have been reported in the literature. The first description of this anomaly was reported in 1966 1. Most patients have associated conotruncal anomalies, such as truncusarteriosus, interrupted aortic arch, tetralogy of Fallot2 ,3, and other congenital and chromosomal abnormalities including trisomy 18 and 22q11 deletions 1. Our research in English literature showed only one case of crossed pulmonary arteries with double aortic arch 4. However our case was diagnosed during infancy .Crossed pulmonary arteries must be distinguished from LPA sling, in which the LPA courses between the trachea and the esophagus, thus causing mechanical compression5. In our case the LPA courses anterior to the trachea and there is no mechanical compression and hemodynamic compromise. Carful echocardiographic examination will help in diagnosis this rare anomaly 6as well as antenatally7.Three-dimensional CT provided a noninvasive approach to clearly recognize these malformations and the related anatomic structures. The prognosis of this rare anomaly is relatively good unless is accompanied by other structural heart or chromosomal abnormalities. In our case the crossed pulmonary arteries were associated with double aortic arch.

References

1. Jue KL, Lockman LA, Edwards JE. Anomalous origins of pulmonary arteries from pulmonary trunk (“crossed pulmonary arteries”). Am Heart J 1966; 71: 807–812.

2.Wolf AJ, Casta A, Nichols M. Anomalous origin and malposition of the pulmonary arteries (crisscross pulmonary arteries) associated with complex congenital heart disease. PediatrCardiol1986; 6: 287–291.

3.Chaturvedi R, Mikailian H, Freedom RM. Images in congenital heart disease: crossed pulmonary arteries in tetralogy of Fallot. Cardiol Young2005; 15: 537.

4. Shunmugasundaram P, Bijulal S, Titus T, TharakanJA.Crisscross pulmonary artery with double aortic arch: an unusual association. PediatrCardiol. 2012 Jun;33(5):857-8. doi: 10.1007/s00246-012-0259-y. Epub 2012 Mar 13.

5. Bamman JL, Ward BH, Woodrum DE. Aberrant left pulmonary artery. Clinical and embryologic factors. Chest. 1977 Jul;72(1):67-71.

6. Babaoğlu K, Altun G, Binnetoğlu K, Dönmez M, Kayabey Ö, Anık Y.Crossed pulmonary arteries: a report on 20 cases with an emphasis on the clinical features and the genetic and cardiac abnormalities.PediatrCardiol. 2013 Dec;34(8):1785-90.

7. Xiong Y, Gan HJ, Liu T, Tao F, Wang HF, Wu Y.Prenatal diagnosis of crossed pulmonary arteries.UltrasoundObstet Gynecol. 2010 Dec;36(6):776-7. doi: 10.1002/uog.8828