Severe Haemoptysis due to Pulmonary Artery Agenesis, About Two Rare but Threatening Case Reports

Abstract

ABSTRACT

Unilateral pulmonary artery agenesis (UPAA) is a rare condition that may be asymptomatic or present with recurrent infections and haemoptysis. A 17‐year‐old patient with severe haemoptysis who was diagnosed with right pulmonary artery agenesis, associated with hypertrophy of the homolateral bronchial arteries and numerous systemic collaterals. Despite three embolisation procedures, a high‐risk of recurrence required pneumonectomy. A 45‐year‐old patient with tetralogy of Fallot and a known left pulmonary artery agenesis presented with 300 mL haemoptysis. The attempt of embolisation and closure of a communication between the circumflex artery and the bronchial arterial network failed, leading to left pneumonectomy. Every case of haemoptysis requires a chest CT scan, among other reasons, in order to identify potential UPAA. Management must be multidisciplinary, often involving surgery.

Introduction

Unilateral pulmonary artery agenesis (UPAA) is a rare embryonic malformation of the 6th branchial arch, first described by Fraentzel in 1868 [1–3]. Its incidence is approximately 1 in 200,000 in the young adult population and is sometimes associated with other congenital anomalies such as tetralogy of Fallot, atrial septal defect, aortic coarctation, patent ductus arteriosus, or pulmonary atresia [4]. Bockeria et al. [5] reviewed 352 cases of UPAA, finding 115 without congenital heart defects. Agenesis was found to be right-sided in two-thirds of cases, with no gender predominance [5]. UPAA is in most cases discovered incidentally, often presenting with non-specific clinical symptoms, though haemoptysis accounts for 20% of presentations [4]. Similarly, management is not standardised and depends on the patient's symptoms. Here, we report two distinct cases of UPAA admitted for the management of haemoptysis.

Case Report

Case 1

A 17-year-old man, born at term with no history of recurrent infections during childhood, was hospitalised for the management of haemoptysis, with a total volume of 500 mL over 24 h. His medical history included occasional smoking, asthma, and attention deficit hyperactivity disorder treated with methylphenidate. He had no prior functional limitations, and there was no family history of cardiological or respiratory disease. Six months earlier, he experienced an initial episode of haemoptysis, prompting a consultation at the emergency department. A chest x-ray revealed right pulmonary hypoplasia with an ipsilateral mediastinal deviation, but no CT scan was performed. Since the consultation did not take place in our centre, we do not have any additional information regarding the choice of care provided. An echocardiography demonstrated dextroposition without associated interventricular septal defect, pulmonary hypertension, or patent ductus arteriosus.

At hospitalisation, the patient reported no significant symptoms. The clinical cardio-respiratory examination did not reveal any abnormality, with no apparent thoracic or extra-thoracic malformation. An electrocardiogram showed an isolated right bundle branch block. CT scan revealed the agenesis of the right pulmonary artery and confirmed right lung hypoplasia (Figure 1A,B). Vascularisation of the right lung was provided via systemic bronchial collaterals originating from the aorta and the brachiocephalic trunk (Figures 1A and 2C). Anastomoses were identified between the bronchial arteries and the right coronary artery and the right vertebral artery. Given these results explaining the cause of the bleeding, it was decided not to carry out a bronchoscopy. Embolisation of the right bronchial artery was performed using four coils in the aortic origin posteriorly and four in a collateral of the right subclavian artery.

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Four days after, a 50 mL haemoptysis relapse necessitated further embolisation, with two coils placed in a bronchial artery from the descending thoracic aorta and three in the right internal thoracic artery. A third recurrence of 70 mL haemoptysis occurred 6 days later, requiring an additional coil in the collateral between the right coronary and bronchial arteries. Concurrent right heart catheterisation revealed a mild precapillary hypertension (mean pulmonary arterial pressure 22 mmHg, wedge capillary pressure 7 mmHg, cardiac output 6 L/min, cardiac index 3.5 L/min/m², and pulmonary vascular resistance 2.5 UW).

Due to recurrent episodes and the lack of additional embolisation targets, a right pneumonectomy was performed a few weeks later. The explant revealed an upper lobe (15 × 8 cm), middle lobe (13 × 6 cm) and lower lobe (14 × 13 cm) with no tumour formation. Microvascular examination showed no significant remodelling, but slightly ecstatic bronchial arteries with localised wall thickening were observed (Figure 2A). Postoperative recovery was favourable, and the chest x-ray 1 month later showed normal hydric and aeric filling of the cavity with mediastinal shift to the right.

Ten months after pneumonectomy, the patient reported no haemoptysis or dyspnoea. Pulmonary function tests indicated a mild restrictive ventilatory defect with a total lung capacity of 4.9 L (75% of the normal value) without diffusion impairment (diffusing capacity of lung for carbon monoxide/alveolar volume = 92%). There were no clinical (no dizziness, syncope or right heart failure), biological (BNP 14 pg/mL) or echocardiographic signs of pulmonary hypertension (estimated systolic pulmonary artery pressure 20 + 5 mmHg, tricuspid regurgitation velocity 2.2 m/s). Given these findings, right heart catheterisation was deemed unnecessary, and an annual follow-up was planned.

Case 2

A 45-year-old man was referred for persistent haemoptysis following unsuccessful bronchial arterial embolisation. He had a history of surgical repair for tetralogy of Fallot diagnosed at birth, and agenesis of the left pulmonary artery with major aorto-pulmonary collateral arteries was known. Until then, he had an almost normal life. He was hospitalised with 300 mL of haemoptysis. CT imaging revealed a large collateral artery from the left descending aorta and another from an arterial trunk originating at the aortic arch (Figure 1D,E). No bronchoscopy was performed. On day 2, distal embolisation of the left bronchial artery was performed using two syringes of 700–900 μm particles. However, he experienced a relapse with 250 mL haemoptysis 7 days later, prompting a second intervention. Coronary angiography confirmed a communication between the circumflex artery and the bronchial arterial, which could not be occluded. After multidisciplinary consultation, a left pneumonectomy was performed. The explant measured 17 × 13 cm, with no tumour identified. Findings included tortuous bronchial arteries with thickened walls and occasional calcifications. Cystic lesions and areas of subpleural fibrosis were also found (Figure 2B,C). Three months post-surgery, the patient's recovery was favourable, and he reported no symptoms.

Discussion

Unilateral pulmonary artery agenesis is a rare malformation, typically associated with a normal pulmonary artery trunk. Systemic collaterals develop, sometimes involving coronary arteries, as seen in our first patient [5–7]. Clinical presentation varies depending on associated cardiac anomalies such as tetralogy of Fallot, atrial septal defect, coarctation of the aorta, right aortic arch, truncus arteriosus, and pulmonary atresia. Unilateral agenesis may remain asymptomatic for years or may be discovered during pulmonary infections, haemoptysis, or pulmonary hypertension investigations, which occur in about 25% of cases [3, 7, 8]. Pulmonary hypertension results from increased blood flow in the remaining lung, compounded by chronic vasoconstriction, secretion of vasoconstrictive agents (endothelin), and vascular remodelling [2, 7]. Ipsilateral lung hypoplasia contributes to poor mucociliary clearance, leading to recurrent infections. Haemoptysis typically arises from systemic hypervascularisation, involving bronchial arteries or chest wall vessels such as intercostal, phrenic, or subclavian artery [9]. As in this case, diagnosis is suggested by a chest x-ray showing pulmonary hypoplasia and an elevated diaphragmatic cupola, and confirmed with contrast-enhanced CT, MRI, or echocardiography [8].

Management depends on clinical presentation, with no established consensus. For haemoptysis, selective embolisation may be attempted, though challenging due to collateral diversity [7, 10]. Surgery is often required and optimally delayed until bleeding ceases [4, 11]. Overall mortality is estimated at 7%, primarily due to massive haemoptysis, cardiac failure, or respiratory failure [4]. Regular echocardiographic monitoring helps detect pulmonary hypertension early [7].

Finally, these two cases highlight the varied presentations and diagnostic circumstances of pulmonary artery agenesis. A multidisciplinary approach is essential for management.

Author Contributions

Marina Gueçamburu: writing, original draft. Anne-Claire Toublanc: manuscript drafting. Michel Montaudon: manuscript drafting. Jacques Jougon: manuscript drafting. Léo Grassion: manuscript drafting. Hugues Bégueret: manuscript drafting. Maéva Zysman: manuscript drafting. Arnaud Maurac: data interpretation, manuscript drafting.

Ethics Statement

The authors declare that appropriate written informed consent was obtained for the publication of this manuscript and accompanying images.

Conflicts of Interest

Léo Grassion reports grants from AADAIRC, AVAD, payment for lectures, presentations, speakers bureaus, manuscript writing or educational events from SOS Oxygène, ANTADIR, RESMED, ASV Santé, Chiesi, Boerhinger Inheleim, AstraZeneca, ASTEN, support for attending meetings and/or travel from ALIZE, ISIS Medical, SOS Oxygène, Asten, participation on a Data Safety Monitoring Board or Advisory Board from VIVISOL, ALMS, RESMED. Maéva Zysman reports grants and personal fees from Boehringer Ingelheim, personal fees from Novartis, personal fees from Chiesi, personal fees from Astra Zeneca, personal fees from CSLBehringand personal fees from GSK outside the submitted work, as well as grants from AVAD and grants from FRM. The other authors declare no conflicts of interest.

Data Availability Statement

The data used are available from the corresponding author on reasonable request.

References

O. Fraentzel, “Ein Fall Von Abnormer Communication Der Aorta Mit Der Arteria Pulmonalis,” Archiv für Pathologische Anatomie und Physiologie und für Klinische Medizin 43, no. 3 (1868): 420–426.

P. E. Pool, J. H. Vogel, and S. G. Blount, “Congenital Unilateral Absence of a Pulmonary Artery. The Importance of Flow in Pulmonary Hypertension,” American Journal of Cardiology 10 (1962): 706–732, [DOI: https://dx.doi.org/10.1016/0002-9149(62)90248-5].

J. Jougon, M. Ballester, F. Delcambre, et al., “Massive Hemoptysis: What Place for Medical and Surgical Treatment,” European Journal of Cardio‐Thoracic Surgery 22, no. 3 (2002): 345–351.