Proximal interruption of a pulmonary artery

Proximal Interruption of Pulmonary Artery: Spectrum of Radiological Findings With Emphasis on Chest Radiograph and Contrast-Enhanced Computed Tomography (CECT)

Introduction Proximal interruption of pulmonary artery (PIPA) is a congenital anomaly presenting with aberrant termination of the pulmonary artery at the hilum. It results in a variety of radiological and clinical manifestations. Clinically, isolated PIPA can be asymptomatic till late adulthood or can present with dyspnoea, chest discomfort, hemoptysis and recurrent infections. PIPA can be associated with multiple cardiovascular anomalies such as tetralogy of Fallot (TOF), ventricular septal defects (VSD), and scimitar syndrome. We present a spectrum of cases with both isolated proximal interruption of the pulmonary artery and cases associated with other cardiovascular abnormalities. Typical chest radiographs and chest contrast-enhanced computed tomography (CECT) findings are discussed and demonstrated in detail. Proper and early diagnosis is a crucial step as it can significantly modify the treatment choice, thereby reducing morbidity. Objective To document the different presentations of the proximal arrest of pulmonary arteries, to document associations with cardiovascular and pulmonary manifestations, and to elaborate on and demonstrate the various radiological imaging findings. Material and methods All the cases that were reported with proximal interruption of pulmonary artery on the CECT studies conducted between 2019 and 2022 at a tertiary care hospital in Telangana, India. The demographic data, clinical presentation, chest radiographs, and chest CECT were collected retrospectively. Data analysis was done using Microsoft Excel 2019 to calculate descriptive statistics. A total of 22 cases were identified of which three cases were excluded of as they were previously operated and 19 cases were taken as the study population. Results Nineteen patients were included in the study. Demographic details, clinical history, CECT, and chest radiographs were collected wherever available. The majority of the cases belonged to the ≤ 10 yrs age group with the most common clinical presentation being a previous diagnosis of tuberculosis or recurrent upper respiratory tract infections. The predominant findings on chest radiographs were deviation of the trachea to the affected side, volume loss in the ipsilateral lung field, and compensatory hyperinflation of the contralateral lung field. On the CECT chest, the main findings were interrupted pulmonary artery, hypoplastic lung fields with bronchiectasis, or ground glassing. Associated cardiovascular and pulmonary malformations were identified with notable cases: TOF, right-sided aortic arch and scimitar syndrome. Their typical imaging findings have been elucidated and discussed in detail. Conclusions Patients with recurrent respiratory infections or hemoptysis having hypoplastic lung field with hyperinflation of the contralateral lung on chest radiographs should be evaluated for pulmonary artery interruptions. Chest CECT allows evaluation of the bronchial tree and lung parenchyma at the same time which helps distinguish pulmonary interruption from conditions such as Swyer-James-Macleod syndrome, pulmonary hypoplasia, thromboembolism and arteritis. Cases with PIPA can also be associated with cardiovascular and pulmonary anomalies such as TOF, partial anomalous pulmonary venous connection (PAPVC), and VSD. The knowledge of these associations is essential as they can influence the mode of treatment and can help reduce the long-term morbidity and mortality associated with the condition.

Proximal interruption of the pulmonary artery: A review of radiological findings

OBJECTIVES

Proximal interruption of the pulmonary artery (PIPA) has various clinical manifestations. This review focused on and summarized the clinical and radiological features of PIPA, based on relevant literature studies.

METHODS

The study included a total of 25 PIPA cases in the Guangzhou Women and Children's Medical Center between January 2015 and December 2021. Conventional chest photographs and chest computed tomography angiography (CCTA) of patients with PIPA were analyzed and summarized.

RESULTS

The radiological results showed that 17 cases were right-sided and 8 cases were left-sided PIPA. Additionally, the percentage of pulmonary hypoplasia on the affected side was 44%, 36% for pulmonary hypertension, 28% for the mosaic sign, 20% for subpleural cystic lucency shadow, 20% for subpleural serrated shadow, 20% for collateral vessel thickening, 16% for subpleural band-like parenchyma, 12% for pneumonia, and 56% for patent ductus arteriosus.

CONCLUSION

The clinical manifestations of PIPA are non-specific. Awareness of this anomaly, based on radiological manifestations, particularly those observed on CCTA images, is important for ruling out alternative diagnoses and implementing appropriate management.

Unilateral proximal interruption of pulmonary artery with ipsilateral interstitial lung disease - A rare case report

Unilateral proximal interruption of pulmonary artery with ipsilateral occurrence of lung fibrosis is a very rare entity. This case report is about a 27 year old male who had complaints of progressive dysponea since 1 year. He had past history of recurrent lower respiratory tract infections. On auscultation, velcro crackles are heard on right side. Pulmonary function test showed restrictive pattern. Chest Radiography, High Resolution Computed Tomography and CT Pulmonary angiography were performed.

Congenital isolated unilateral agenesis of pulmonary arteries in adults: case series and review

Congenital, isolated unilateral agenesis of pulmonary arteries (UAPA) has a bimodal clinical presentation. It is either diagnosed in early infancy or during adulthood. Early diagnosis and timely surgical correction at infancy prevent the development of irreversible pulmonary hypertension and enable prolonged survival. Though surgical intervention is a conclusive method of treatment, its outcome depends upon the reversibility of pulmonary hypertension and the adequacy of the pulmonary artery dimension. Adults with UAPA can be asymptomatic (diagnosed incidentally) or symptomatic. They may present clinically with myriads of symptoms like exertional dyspnea, recurrent lung infection, hemoptysis, and atypical chest pain. For cases where definitive surgical treatment is not feasible, interventional and medical management should be carried out as part of palliative therapy. A retrospective analysis of 22 cases of UAPA in adults published in the literature from the years 2017-2020 are presented here, along with our institutional case.

Non-bronchial causes of haemoptysis: imaging and interventions

Purpose

To describe non-bronchial causes of haemoptysis on imaging and the role of interventional radiology in their management from cases of haemoptysis archived from our database at a tertiary care, federally funded institution.

Material and methods

Retrospective analysis of cases that presented with haemoptysis in our institution from 2008 to 2013 was done, and details of cases in which the bleeding was from a non-bronchial source were archived and details of imaging and treatment were recorded.

Results

Retrospective analysis of patients presenting with haemoptysis yielded 24 (n = 24) patients having haemoptysis from non-bronchial sources. Causes of haemoptysis were: Rasmussen aneurysms (n = 12/24), costocervical trunk pseudoaneurysm (n = 1/24), left internal mammillary artery pseudoaneurysm (n = 1/24), left ventricular aneurysms (n = 3/24), pulmonary arteriovenous malformations (AVMs) (n = 5/24), and proximal interruption of pulmonary artery (n = 2/24). Imaging and interventional radiology management are described in detail.

Conclusions

Haemoptysis can be from non-bronchial sources, which may be either from systemic or pulmonary arteries or cardio-pulmonary fistulas. Bronchial computed tomography angiography (CTBA), if feasible, must always be considered before bronchial artery embolisation because it precisely identifies the source of haemorrhage and vascular anatomy that helps the interventional radiologist in pre-procedural planning. This circumvents chances of re-bleed if standard bronchial artery embolisation is done without CTBA.

Pulmonary arteries: imaging of pulmonary embolism and beyond

The pulmonary arteries are not just affected by thrombus. Various acquired and congenital conditions can also affect the pulmonary arteries. In this review we discuss cross sectional imaging modalities utilized for the imaging of the pulmonary arteries. Acquired pulmonary artery entities, including pulmonary artery sarcoma (PAS), vasculitis, aneurysm, and arteriovenous malformations, and congenital anomalies in adults, including proximal interruption of the pulmonary artery, pulmonary sling, pulmonary artery stenosis, and idiopathic dilatation of the pulmonary trunk, are also discussed. An awareness of these entities and their imaging findings is important for radiologists interpreting chest imaging.

Cross-sectional imaging of congenital pulmonary artery anomalies

Congenital pulmonary artery (PA) anomalies comprise a rare and heterogeneous spectrum of disease, ranging from abnormal origins to complete atresia. They may present in early infancy or more insidiously in adulthood, often in association with congenital heart disease such as tetralogy of Fallot or other syndromes. In recent years, cross-sectional imaging, including computed tomography (CT) and magnetic resonance imaging (MRI), has become widely utilized for the noninvasive assessment of congenital PA diseases, supplementing echocardiography and at times supplanting invasive angiography. In this article, modern CT and MRI techniques for imaging congenital PA disorders are summarized. The key clinical features, cross-sectional imaging findings, and treatment options for the most commonly encountered entities are then reviewed. Emphasis is placed on the ever-growing role of cross-sectional imaging options in facilitating early and accurate diagnosis and tailored treatment.

Proximal Interruption of the Pulmonary Artery

Proximal interruption of the pulmonary artery (PIPA) is an uncommon developmental anomaly resulting in underdevelopment of the proximal portion of the pulmonary artery with preservation of the intrapulmonary segments. Clinical presentation ranges between an asymptomatic incidental finding to massive hemoptysis. When findings suggestive of PIPA are present radiographically, the diagnosis of PIPA can be definitively diagnosed with computed tomography or magnetic resonance pulmonary angiography. Other imaging modalities, such as nuclear perfusion scan and catheter angiography can help in the diagnosis.

Proximal Interruption of the Pulmonary Artery: A Case Series

We present a few cases of Proximal Interruption of the Pulmonary Artery, an uncommon developmental anomaly associated with congenital heart disease. The cases had varied clinical presentations. Chest radiograph showed a hypoplastic lung with an ipsilateral small hilum on the side of the interruption and hyperinflation of the contralateral lung. Contrast CT confirmed the diagnosis, demonstrating non-visualization of the left or right pulmonary artery, and other related findings.

Bronchial arteries: anatomy, function, hypertrophy, and anomalies

The two main sources of blood supply to the lungs and their supporting structures are the pulmonary and bronchial arteries. The bronchial arteries account for 1% of the cardiac output but can be recruited to provide additional systemic circulation to the lungs in various acquired and congenital thoracic disorders. An understanding of bronchial artery anatomy and function is important in the identification of bronchial artery dilatation and anomalies and the formulation of an appropriate differential diagnosis. Visualization of dilated bronchial arteries at imaging should alert the radiologist to obstructive disorders that affect the pulmonary circulation and prompt the exclusion of diseases that produce or are associated with pulmonary artery obstruction, including chronic infectious and/or inflammatory processes, chronic thromboembolic disease, and congenital anomalies of the thorax (eg, proximal interruption of the pulmonary artery). Conotruncal abnormalities, such as pulmonary atresia with ventricular septal defect, are associated with systemic pulmonary supply provided by aortic branches known as major aortopulmonary collaterals, which originate in the region of the bronchial arteries. Bronchial artery malformation is a rare left-to-right or left-to-left shunt characterized by an anomalous connection between a bronchial artery and a pulmonary artery or a pulmonary vein, respectively. Bronchial artery interventions can be used successfully in the treatment of hemoptysis, with a low risk of adverse events. Multidetector computed tomography helps provide a vascular road map for the interventional radiologist before bronchial artery embolization.

Imaging diagnosis of isolated proximal interruption of the right pulmonary artery in a patient presenting with respiratory complications following travel to a high-altitude region

Proximal interruption of the pulmonary artery (PA) is a rare congenital vascular anomaly with an estimated prevalence of 1 in 200,000 young adults. Patients with isolated proximal interruption of the right PA are usually asymptomatic but can present with breathlessness, haemoptysis, recurrent chest infections, pulmonary hypertension or respiratory failure. Such symptoms may be unmasked by pregnancy or at high altitude. We present a case of an isolated interruption of the right PA in a 29-year-old male with a history of cough and breathlessness, requiring hospitalization and ventilator support after travel to a hilly region. Laboratory reports showed normal haemogram and normal renal and liver function tests. Screening test for deep vein thrombosis/pulmonary embolism were negative. Echocardiogram was normal and did not show any evidence of elevated PA pressures. All serial X-rays were reviewed and showed one consistent finding: right lung volume loss with transmediastinal herniation of the left lung to the right side. We discuss the radiological and clinical features along with treatment options for the condition.

Looking beyond the thrombus: essentials of pulmonary artery imaging on CT

Background

Pulmonary arteries are not just affected by thrombus. Congenital and acquired conditions can also involve the pulmonary arteries. An awareness of these conditions is important for the radiologist interpreting chest computed tomography (CT).

Methods

The anatomy of the pulmonary arteries was reviewed. CT and magnetic resonance (MR) acquisition protocols for imaging the pulmonary arteries were discussed. The imaging appearances of congenital and acquired anomalies involving the pulmonary arteries, using CT and other modalities, were presented.

Results

Imaging features of congenital anomalies presented include pulmonary agenesis, partial pulmonary artery agenesis, patent ductus arteriosus, pulmonary artery sling, congenital pulmonary artery stenosis and coronary to pulmonary artery fistula. Acquired pulmonary artery anomalies discussed include arteritis, infected aneurysm and sarcoma. Pulmonary artery filling defects besides thromboembolism are also discussed, including foreign body emboli. Imaging features of bronchogenic carcinoma and mediastinal fibrosis demonstrating compression of the pulmonary arteries are presented, followed by a brief discussion of post repair appearance of the pulmonary arteries for congenital heart disease.

Conclusions

Congenital and acquired pulmonary artery anomalies have a characteristic appearance on a variety of imaging modalities. An acquaintance with the imaging features of these anomalies is needed to avoid misinterpretation and reach the correct diagnosis.

Teaching Points

• Discuss a variety of congenital and acquired anomalies of the pulmonary arteries.

• Discuss the imaging appearance of the presented congenital or acquired pulmonary artery anomalies.

• Describe CT and MR acquisition protocols for imaging the pulmonary arteries.

• Review the anatomy of the pulmonary arteries.

Chronic pulmonary emboli and radiologic mimics on CT pulmonary angiography: a diagnostic challenge

Chronic pulmonary thromboembolism (CPE) is a challenging diagnosis for clinicians. It is an often-forgotten diagnosis and can be difficult to detect and easily misdiagnosed. The radiologic features on CT pulmonary angiography are subtle and can be further compounded by pathologic mimics and unusual findings observed with disease progression. Diagnosis is important because CPE can lead to progressive pulmonary hypertension, morbidity, and mortality. Moreover, chronic thromboembolic pulmonary hypertension is the only category of pulmonary hypertension with an effective curative treatment in the form of pulmonary endarterectomy. Therefore, CPE must be considered and recognized early. The features of chronic pulmonary emboli on CT scans can be categorized into vascular or parenchymal findings. Endoluminal signs include totally or partially occlusive thrombi and webs and bands. Parenchymal features such as mosaic attenuation and pulmonary infarction are also noted, in addition to features of pulmonary artery hypertension. Additional findings have been noted, including cavitation of infarcts, microbial colonization of cavities, and bronchopleural fistulae. As CPE can be diagnosed at different stages of its disease pathway, such findings may not necessarily arouse suspicion toward a causative diagnosis of chronic embolism. To aid diagnosis for clinicians, this article describes the characteristic vascular and parenchymal CT scan features of chronic emboli, as well as important ancillary findings. We also provide an illustrative case series focusing on CT pulmonary angiography specifically as an imaging modality to highlight the progressive nature of CPE and its sequelae, as well as important radiologic mimics to consider in the differential diagnosis.

Congenital absence of the right interlobar pulmonary artery: HRCT findings

We report a case of unilateral idiopathic pulmonary fibrosis-like changes in the right middle and lower lobe without lung volume changes and with normal upper lobe owing to congenital absence of the right interlobar pulmonary artery on chest computed tomography.

Congenital and acquired pulmonary artery anomalies in the adult: radiologic overview

Various congenital and acquired anomalies may affect the pulmonary arteries in adult patients. Congenital anomalies (proximal interruption, anomalous origin of the left pulmonary artery [pulmonary artery sling], and idiopathic dilatation of the pulmonary trunk) are usually found incidentally at chest radiography or computed tomography (CT). Acquired anomalies include diffuse or focal enlargement of the arteries because of pulmonary hypertension, aneurysm, and intravascular pulmonary metastasis; decreased arterial diameter because of bronchial carcinoma, mediastinal fibrosis, and Takayasu arteritis; and intraluminal filling defects due to pulmonary thromboembolism and pulmonary artery sarcoma. An awareness of the radiologic manifestations of the disease entities and potential pulmonary artery complications secondary to infection or vasculitis may enable an early diagnosis. CT angiography is becoming the standard method for evaluating patients in whom the presence of pulmonary embolism is suspected. CT assessment of the extent of heart effects in patients with pulmonary hypertension and pulmonary embolism is particularly important because such effects largely determine the prognosis.

Agénésie isolée de l'artère pulmonaire. À propos de huit observations

Unilateral primitive agenesia of pulmonary artery is a rare congenital disorder. Experience of three hospital-based pulmonology pediatric units including eight children (three boys and five girls) with such anomaly is reported (11 years median follow-up, range 6 months to 10 years). Median age at diagnosis was 4 years. Clinical features included recurrent respiratory tract infections (75%), effort dyspnea (50%) and, curiously, asthmatic symptoms (75%). Diagnosis was evoked on chest X rays and confirmed by angiography in all cases. Agenesis of the right pulmonary artery was more frequent (five cases). Abnormal vascular ring was associated in two cases of agenesis of the left pulmonary artery. Pulmonary function tests were performed in six children, with bronchial obstruction in two. Regular clinical follow-up, up to adult age in four cases, showed no complication, such as hemoptysis or pulmonary hypertension in our patients.

HRCT Findings of Proximal Interruption of the Right Pulmonary Artery

The purpose of this study is to present the characteristic HRCT findings of the lung parenchyma in patients with proximal interruption of the right main pulmonary artery. HRCT findings of proximal interruption of the right pulmonary artery demonstrated reticular opacities, septal thickening, subpleural consolidation, cystic lung changes, and pleural thickening in all 5 patients; bronchial dilation and bronchial wall thickening in 4 patients; and subpleural ground glass opacity (GGO) in 3 patients. The changes may be caused by absent pulmonary artery perfusion and development of systemic vessel collateralization.

Unilateral pulmonary oedema in a patient with hypertrophic cardiomyopathy and severe narrowing of the left pulmonary artery

A patient with hypertrophic cardiomyopathy developed unilateral right sided pulmonary oedema. Pulmonary angiography showed a proximal severe narrowing of the left pulmonary artery.

Occult pulmonary artery associated with failure to thrive and recurrent pneumonia--a case report

Occult pulmonary artery is an uncommon cardiovascular defect. Associated symptoms include recurrent pulmonary infections and congestive heart failure. The authors describe a one-year-old boy initially diagnosed as having broncho-pulmonary dysplasia who developed severe failure to thrive, recurrent pneumonias, and pulmonary hypertension. The presence of an occult right pulmonary artery was suspected by lung perfusion scan and diagnosed by cardiac catheterization and angiography. After surgical repair, his clinical course improved and his growth and development were normal. This case demonstrates the importance of including occult pulmonary artery in the differential diagnosis of infants with failure to thrive associated with recurrent pulmonary infection.

Pulmonary artery agenesis presenting as massive hemoptysis--a case report

Massive hemoptysis is the expectoration of approximately 600 ml of blood in twenty-four hours. Major causes of massive hemoptysis are tuberculosis, bronchiectasis, pulmonary neoplasm, fungus ball, bronchial adenomas, lung abscess, intrabronchial rupture of an aortic aneurysm, cystic fibrosis, pulmonary infarction, and pulmonary trauma. Other, less common causes include Goodpasture's syndrome, broncholiths, pulmonary varix, A-V malformation, and bleeding disorders. Agenesis of the pulmonary artery usually occurs in association with congenital cardiac anomalies, and isolated unilateral absence of the pulmonary artery is uncommon. About 10% of the patients with pulmonary artery agenesis develop inconsequential hemoptysis, but massive hemoptysis is a very rare complication of this anomaly. The following is a case report of a twenty-nine-year-old man with agenesis of the left pulmonary artery, who presented with massive hemoptysis requiring embolization and, eventually, pneumonectomy.

Surgical management of absent right pulmonary artery with associated pulmonary hypertension

A critically ill 21-month-old girl with congenital absence of the right pulmonary artery and severe pulmonary hypertension and congestive heart failure underwent conduit restoration of flow to the right lung. This patient had marked clinical improvement and reduction in pulmonary hypertension and represents the second reported surgically-treated case for absent right pulmonary artery. Reestablishment of pulmonary artery continuity is therefore recommended when cardiac failure and pulmonary hypertension occurs.

Effects of mild chronic hypoxia on the pulmonary circulation in calves with reactive pulmonary hypertension

The effects of the mild hypoxia at an altitude of 5280 ft on the pulmonary circulation were examined in normal calves and calves with a preexisting stimulus to maintain a reactive pulmonary vascular bed. In a serial study, 9 calves born at 5280 ft and 9 calves born at sea level underwent left pulmonary artery (LPA) ligation; 3 calves born at 5280 ft and 8 calves born at sea level underwent right pulmonary artery (RPA) ligation within 24 to 48 hours after birth. Progressive pulmonary hypertension and right ventricular heart failure developed in all calves operated on at 5280 ft but not in those with LPA ligation performed at sea level until they were transferred to 5280 ft. In contrast, in some animals with RPA ligation at sea level, progressive pulmonary hypertension was noted. The increased pulmonary blood flow consequent to LPA ligation does not result in progressive pulmonary hypertension at sea level but the addition of the mild hypoxia at 5280 ft appears to provide additional sufficient stimulus to result in progressive pulmonary hypertension. However, the slightly higher pulmonary blood flow subsequent to RPA ligation is capable of producing progressive pulmonary hypertension at sea level. Correlation was found between these results and human patients with congenital unilateral absence of a pulmonary artery, indicating that, in subjects with some stimulus to maintain a reactive pulmonary vascular bed, the mild hypoxia of 5280 ft may exert a significant effect on the pulmonary circulation.