Ann Thorac Surg 2002;74:2169-2171
© 2002 The Society of Thoracic Surgeons
Case report
Congenital unilateral pulmonary artery agenesis and aspergilloma
Isaac S. Kadir, FRCSa,
Joyce Thekudan, FRCSa,
Anand Dheodar, FRCSa,
Mark T. Jones, FRCSa*,
Kevin B. Carroll, FRCPa
a Department of Cardiothoracic Surgery and Medicine, Wythenshawe Hospital, Wythenshawe, Manchester, England, UK
Accepted for publication June 28, 2002.
* Address reprint requests to Dr Jones, Department of Cardiothoracic Surgery, Wythenshawe Hospital, Southmoor Road, Wythenshawe, Manchester, England M23 9LT, UK
e-mail: mark.jones{at}smuht.nwest.nhs.uk
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Abstract
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Isolated unilateral pulmonary artery agenesis is a rare condition, which in most patients is asymptomatic. Occasionally patients present with symptoms that are nonspecific and not necessarily attributable to disease of the respiratory system. In these individuals the clue to the diagnosis is found in a plain chest roentgenogram, often revealing a hyperlucent contracted hemithorax. We present an unusual case of isolated unilateral pulmonary artery agenesis associated with the opportunistic organism Mycobacterium kansasii and Aspergillus fumigatus in which the diagnosis was made 10 years after initial presentation. Clinicians should be aware of this condition and include it in their differential diagnosis of a hyperlucent lung field on the chest roentgenogram.
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Introduction
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Unilateral pulmonary artery agenesis (UPAA) is a rare condition often associated with other congenital abnormalities. Although isolated UPAA is even rarer and usually asymptomatic, it has been associated with a range of symptoms including hemoptysis, exertional dyspnea, and chest pain [1, 2]. The lack of a pulmonary arterial blood supply coupled with recurrent episodes of chronic bronchitis and bronchiectasis renders the affected lung susceptible to infection. We describe a patient with a slightly unusual bronchial anatomy who presented with an opportunistic Mycobacterium kansasii pneumonia and who ultimately required pneumonectomy for symptom control.
A 22-year-old woman presented in May 1989 with M. kansasii pneumonia for which she was commenced on antituberculous medications. Her chest roentgenogram showed a mediastinum that was shifted to the right, a contracted right hemithorax, and cavitation in the right midzone. She again presented in March 1990 with fever, right-sided pleuritic chest pain, night sweats, and an expectorant cough. In addition to the cavitating lesion in the right midzone noted previously, a new right paratracheal shadow was noted on the chest film. Reactivation of her atypical mycobacterial infection was suspected and antituberculous medications were continued. Her symptoms settled with conservative treatment and in July 1991, in the absence of any microbiological evidence of active tuberculosis, her antituberculous medications were discontinued. She continued to expectorate blood-tinged sputum and by January 1992 she complained of weight loss and exertional dyspnea. In December 1992, while 37 weeks pregnant, she presented with massive hemoptysis with frequent expectoration. Her sputum culture yielded Aspergillus organisms with a high titer of A. precipitins in her blood.
After her successful pregnancy she underwent extensive physical examination. A bronchoscopic examination was normal apart from there being only two subdivisions in the right upper lobe bronchus. Pulmonary function tests revealed slight reduction in lung volumes with little or no reduction in transfer factor. A computed tomography scan showed a slightly contracted right hemithorax with ipsilateral mediastinal shift, hypoplastic right lung and bronchial tree, and a 4.5-cm cavity in the anterior segment of the right upper lobe. There appeared to be a fungus ball within the cavity. Evidence of bronchiectasis was noted in the right middle lobe with generalized interstitial thickening. The left lung was normal. A diagnosis of Macleod’s syndrome was made and conservative treatment was continued.
The patient’s symptoms persisted; moreover, her hemoptysis, although mild, was now more frequent. A nuclear ventilation-perfusion scan (V/Q) scan revealed a complete absence of perfusion to the right lung in the presence of slightly diminished ventilation. Normal ventilation and perfusion to the left lung was noted (Fig 1).
A diagnosis of UPAA was made and a pulmonary angiogram and aortogram was performed. The pulmonary angiogram demonstrated a normal pulmonary trunk, complete atresia of the right pulmonary artery, and a normal left pulmonary artery. The aortogram showed that the blood supply to the right lung was from a large right bronchial artery arising from the undersurface of the aortic arch at the level of the left subclavian artery (the intercostobrachial trunk). This supply was supplemented by large branches from the right internal mammary, inferior phrenic, and lateral thoracic arteries (Fig 2).
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Fig 1. Ventilation-perfusion scan showing reduced ventilation and absent perfusion in the right lung compared with normal ventilation and perfusion in the left lung. Left = perfusion scan; right = ventilation scan.
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Fig 2. Aortogram demonstrating the blood supply to the right lung arising from branches of the right internal thoracic and lateral thoracic arteries. The arterial supply to the Aspergillus-containing cavity is seen as a prominent vascular blush arising from the lateral thoracic arteries.
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Her symptoms did not improve and her quality of life was gradually deteriorating. The demonstration of an aspergilloma within the lung cavity with the risk of a fatal hemoptysis prompted consideration of a pneumonectomy, which was performed July 2000. At surgery, multiple vascular adhesions between the lung and the chest wall and diaphragm were encountered. No pulmonary artery was observed; however, numerous small vessels entered the lung at the hilum. Her postoperative recovery was uncomplicated and the patient was asymptomatic 18 months after surgery. Histology of the resected lung revealed an absent pulmonary artery with prominent bronchial arteries. Mild alveolar duct emphysema was noted, in addition to a 3 x 4 cm cavity containing Aspergillus organisms.
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Comment
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Unilateral pulmonary artery agenesis is a rare congenital abnormality with an incidence estimated at 1 in 300,000. It is frequently associated with other congenital cardiac anomalies such as tetralogy of Fallot, persistent ductus arteriosus, right-sided aortic arch, atrial and ventricular septal defects, aortopulmonary window, and total anomalous pulmonary venous drainage. When associated with these cardiac lesions, the left lung is most frequently affected and the resulting hemodynamic abnormality usually results in presentation and diagnosis within the first year of life [3].
Unilateral pulmonary artery agenesis as an isolated phenomenon is even rarer and patients affected are asymptomatic or present with symptoms that are either nonspecific or are discovered upon investigation after the discovery of an abnormal chest roentgenogram. In this subset of patients, the right lung is predominantly affected and patients usually present in early adulthood, although some present as late as the fifth or sixth decade of life [2, 3].
An important effect of the absence of pulmonary artery blood supply is the development of much increased bronchial artery collateral. Bronchospirometry investigations estimate that 17% instead of the usual 1% of the systemic cardiac output enters the affected lung through the bronchial arteries. An additional source of collateral blood flow is through the intercostals arteries, which usually gain access to the lung through vascular pleural adhesions. These increased ramifications of the bronchial and intercostal collaterals are especially prominent in the lung apices and can be detected on the chest roentgenogram as a finding of pulmonary pseudo-fibrosis. Approximately 10% of patients present with hemoptysis, which is thought to be due to hemorrhage into the lung parenchyma as a result of high arterial pressure in the bronchial arterioles and venules, which are attempting to replace the absent pulmonary circulation [4, 5].
Recurrent pulmonary infections are a frequent symptom of the condition; however, the pathogenesis of such infection is unclear. One proposed mechanism is thought to be due to bronchoconstriction secondary to alveolar hypocapnia. The bronchoconstriction in turn leads to mucus trapping, chronic bronchitis, and bronchiectasis. In addition, as a result of absent pulmonary perfusion, mucociliary clearance is impaired, as is delivery of the bloodborne inflammatory cells that are necessary to deal with inhaled microorganisms [5]. A consequence of these conditions is that the lung is relatively immunodeficient and readily susceptible to infection by the ubiquitous M. kansasii. It is well known that cavitating disease of the lung provides an ideal milieu for colonization by spores of A. fumigatus, which can increase the risk and severity of hemoptysis associated with this condition. The increased propensity for infection with Mycobacteria organisms is associated with cellular immunodeficiency and one case has been reported of UPAA associated with thymic aplasia [6]. Investigations of both T- and B-cell function in our patient, however, were normal.
Despite the absence of a normal pulmonary artery, the bronchial tree is almost always normal. Bronchoscopy frequently reveals the telltale signs of chronic bronchitis and occasional bronchiectasis. As the affected lung has failed to develop to its normal size, the bronchi usually appear smaller and crowded together. To date, no variations have been reported in bronchial anatomy; in our case only 2 subdivisions were noted in the right upper lobe bronchus. The origin of this anomaly, however, remains uncertain.
Routine pulmonary function tests in patients with UPAA are usually unremarkable or show a mild restrictive defect with an increase ratio of physiologic dead space to tidal volume. The diffusing capacity is frequently decreased consistent with the absence of half of the active alveolar capillary units. Roentgenogram findings include a smaller than normal hyperlucent hemithorax, elevation of the diaphragm, and a mediastinal shift to the affected side. Nuclear ventilation-perfusion scans frequently reveal diminished ventilation on the affected side compared with the normal lung, together with absent perfusion. Alternative yet diagnostic investigations include the use of high-resolution computed tomography scanning, magnetic resonance imaging, digital subtraction angiography, and pulmonary angiography [3]. While selective embolization of systemic vessels may control hemoptysis successfully, recurrent hemoptysis or chest infection and bronchiectasis is an acceptable indication for pneumonectomy in these patients [5, 6][7].
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References
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- Bekoe S., Pellegrini R.V., DiMarco R.F., Jr, Grant K.J., Woelfel G.F. Pneumonectomy for unremitting hemoptysis in unilateral absence of pulmonary artery. Ann Thorac Surg 1993;55:1553-1554.[Abstract]
- Vaughan B.F. Syndromes associated with hypoplasia or aplasia of one pulmonary artery. J Faculty Radiol 1958;9:161-167.
- Bouros D., Pare P., Panagou P., Tsintiris K., Siafakas N. The varied manifestation of pulmonary artery agenesis in adulthood. Chest 1995;108:670-676.[Abstract/Free Full Text]
- Werber J., Ramilo J.L., London R., Harris V.J. Unilateral absence of a pulmonary artery. Chest 1983;84:729-732.[Abstract/Free Full Text]
- Sherrick D.W., Kincaid O.W., DuShane J.W. Agenesis of a main branch of the pulmonary artery. Am J Roentgenol 1962;87:917-928.
- DiGeorge syndrome associated with left lung aplasia. British J Radiol 2001;74:764-766.[Abstract/Free Full Text]
- Rene M., Sans J., Dominguez J., Sancho C., Valldeperas J. Unilateral pulmonary artery agenesis presenting with hemoptysis: treatment by embolization of systemic collaterals. Cardiovasc Intervent Radiol 1995;18:251-254.[Medline]
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Abstract
Introduction
