CASE 13226 Published on 17.12.2015

Absent left main pulmonary artery with patent ductus arteriosus

Section

Cardiovascular

Case Type

Clinical Cases

Authors

Ahmed M. Osman, MD.
Ahmed Abdrabou, MD - FRCR.
Asmaa Mahmoud Naguib, Ms.C.

Ain Shams University hospital, Clinical Radiology; 38 Ramsis Street - EL Abbasia, CAIRO, Egypt. Tel: 002/0224821728, Fax:002/0224821728. Website: http://med.shams.edu.eg.
E. mail: dr_aosman@med.asu.edu.eg
Another E. mail: dr_osman80@yahoo.com

Patient

23 years, female

Categories

Area of Interest Cardiovascular system ; Imaging Technique CT-Angiography

Procedure Contrast agent-intravenous, Computer Applications-3D ; Special Focus Congenital ;

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Clinical History

A 23-year-old female patient complained of dyspnoea, fatigue and repeated attacks of chest pain. Physical examination revealed loud P2 cardiac sound and parasternal heave. Echocardiography was done and revealed pulmonary hypertension with patent ductus arteriosus (PDA). CT pulmonary angiography was arranged as pre-operative investigation before PDA correction surgery.

Imaging Findings

The patient underwent CT pulmonary angiography. The images were taken after contrast injection via a cannula inserted inside the cubital vein. Post processing done when many findings were obvious. The main pulmonary trunk as well as the right pulmonary artery were dilated measuring 35 mm and 31 mm in caliber respectively (Figure 1). There was no sign of the left pulmonary artery which was interpreted as completely absent (Figure 1-3). Moreover, there was a right sided aortic arch and wide patent ductus arteriosus that measured 20 mm in caliber and 18 mm in length and connected the aorta distal to the brachiocephalic artery to the right pulmonary artery (Figure 3). Nevertheless, the left lung was hypoplastic, oligemic and was supplied by bronchial and intercostal arteries associated with abnormally elevated left diaphragmatic copula (Figure 1, 2, 4). Minimal mid-dorsal scoliotic deformity was also noted (Figure 4).

Discussion

Unilateral absence of a pulmonary artery (UAPA) is a rare congenital anomaly which was first described by Fraentzel in 1868 [1]. It is frequently associated with other cardio-vascular anomalies, such as Fallot of tetralogy, septal defects, right aortic arch and patent ductus arteriosus [2-4]. Its prevalence is believed to be 1 in 200.000 live births according to Bouros et al. [2].
The exact embryological cause of UAPA is a matter of debate usually secondary to altered development of the six aortic arch segment [5]. The distal intra-pulmonary branches of the affected artery remain intact and can be supplied by collateral vessels from bronchial, intercostals, internal mammary, subclavian or even coronary arteries [6, 7].
Many patients with isolated UAPA may remain asymptomatic until they reach adulthood [2] while others may complain of recurrent respiratory tract infections, dyspnoea on exertion, pulmonary oedema, pulmonary hypertension or hemoptysis in contralateral lung [8].
Pulmonary hypertension occurring as a sequel to UAPA may result from an increase in blood flow to the contralateral unaffected artery. This leads to chronic vasoconstriction of the pulmonary arteries with subsequent pulmonary hypertension [9]. The aetiology of recurrent infection may be due to decrease the blood flow to the affected lung with subsequent poor delivery of the inflammatory cells associated with alveolar hypocapnia leading to bronchoconstriction and mucous trapping [6]. Hemoptysis may occur due to the large collateral circulation [6, 10].
In our case, the patient remained asymptomatic until the age of 23 when she complained of dyspnoea, fatigue and repeated attacks of chest pain. Physical examination revealed loud P2 cardiac sound and parasternal heave. Echocardiography revealed PDA associated with pulmonary hypertension. CT pulmonary angiography was important to exclude pulmonary causes of pulmonary hypertension.
Regarding the treatment, some recommended just follow up and medical treatment of the pulmonary hypertension [5]. Some attempts were made to revascularize the patent peripheral branches of the affected artery with Blalock Taussig shunt between the SCA and branches of the absent PA [11, 12]. In cases with severe hemoptysis, embolization, lobectomy or even pneumonectomy may be required [10].
Although it is a rare disease it must be recognized as an item in the differential diagnosis of unilateral pulmonary oligemia as well as pulmonary hypertension.

Differential Diagnosis List

Unilateral absent left main pulmonary artery with patent ductus arteriosus.

Pulmonary hypoplasia

Pulmonary Thrombosis

Sywer-James-MacLeod syndrome

Final Diagnosis

Unilateral absent left main pulmonary artery with patent ductus arteriosus.

References

[1] Kumar A, Francis E, and Krishna R. (2010) Isolated absence of right pulmonary artery. Ann Pediatr Cardiol 3(2): 119–122 (PMID: 21234189)

[2] Bouros D, Pare P, Panagou P, Tsintiris K, Siafakas N. (1995) The varied manifestation of pulmonary artery agenesis in adulthood. Chest 108:670–676 (PMID: 7656614)

[3] Werber J, Ramilo JL, London R, Harris VJ (1983) Unilateral absence of pulmonary artery. Chest 84:729–732 (PMID: 6641308)

[4] Borgeson E, Vogel J (1980) Congenital unilateral absence of left pulmonary artery. Chest 77:106–107 (PMID: 7351130)

[5] David W, Reading, MS, and Umesh Oza (2012) Unilateral absence of a pulmonary artery: a rare disorder with variable presentation. Proc (Bayl Univ Med Cent) 25(2):115–118 (PMID: 22481838)

[6] Kadir IS, Th ekudan J, Dheodar A, Jones MT, Carroll KB. (2002) Congenital unilateral pulmonary artery agenesis and aspergilloma. Ann Th orac Surg 74(6):2169–2171 (PMID: 12643413)

[7] Bockeria LA, Makhachev OA, Khiriev TK, Abramyan MA (2011) Congenital isolated unilateral absence of pulmonary artery and variants of collateral blood supply of the ipsilateral lung. Interact Cardiovasc Th orac Surg 12(3):509–510 (PMID: 21345836)

[8] De Mello Junior WT, Roberto J, Santos M, Jose W, and Franc P (2008) Case report: Isolated absence of the right pulmonary artery as a cause of massive hemoptysis. Interactive CardioVascular and Thoracic Surgery 7: 1183–1185 (PMID: 18775917)

[9] Shostak E, Sarwar A (2009) A 50-year-old woman with dyspnea, lower extremity edema, and volume loss of the right hemithorax. Chest 136(2): 628–632 (PMID: 19666764)

[10] Bekoe S, Pellegrini RV, DiMarco RF Jr, Grant KJ, Woelfel GF (1993) Pneumonectomy for unremitting hemoptysis in unilateral absence of pulmonary artery. Ann Thorac Surg 55(6):1553–1554 (PMID: 8512411)

[11] Welch K, Hanley F, Johnston T, Cailes C, Shah MJ (2005) Isolated unilateral absence of right proximal pulmonary artery: surgical repair and follow-up. Ann Thorac Surg 79(4):1399–1402 (PMID: 15797092)

[12] Toews WH, Pappas G (1983) Surgical management of absent right pulmonary artery with associated pulmonary hypertension. Chest 84(4): 497–499 (PMID: 6617289)

Case information

URL:	https://www.eurorad.org/case/13226
DOI:	10.1594/EURORAD/CASE.13226
ISSN:	1563-4086

License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Axial CT pulmonary angiography

CT pulmonary angiography, axial MIP image revealed dilatation of the pulmonary trunk and right main pulmonary artery. Note absence of arterial flow to the left lung

CT pulmonary angiography, axial MIP image revealed oligemic left lung which is supplied with dilated intercostal arteries (yellow arrow).

Figure 2

Coronal, sagittal and 3D volume rendering images

a) Coronal, b) Sagittal MIP and c) rotated 3D VRT images. The white arrow refers to a dilated patent ductus aretriosus. Note the absence of the left main pulmonary artery and right sided aortic arch.

Figure 3

Axial MIP and 3D images of the pulmonary vasculature

CT pulmonary angiography, axial MIP image revealed oligemic left lung with absent left pulmonary arterial supply. This is associated with increased right pulmonary vasculature.

3D- MIP of the pulmonary vasculature revealed oligemic left lung with increased right sided pulmonary vasculature.

3D volume rendering image for the pulmonary arterial tree showing absent left main pulmonary artery.

Figure 4

Coronal CT image with 3D VRT of the lung.

CT pulmonary angiography coronal reformatted image showing hypoplastic left lung with abnormally elevated left diaphragmatic copula. Dorsal scoliotic deformity with convexity to the left side noted.