Common Vascular Source of hemoptysis: Orthotopic bronchial arteries

Orthotopic bronchial arteries have their origins in the proximal descending aorta between the superior endplate of T5 and the inferior endplate of T6. The right bronchial artery can share an origin with an intercostal artery, forming an intercostal-bronchial artery trunk. A common bronchial trunk may be seen occasionally. The branching patterns of bronchial arteries, as outlined by Cauldwell et al., exhibit significant variability [3].  

Fig 1: Cauldwell et al. classification of bronchial artery anatomy. Type I: one right bronchial artery from the right intercostobronchial trunk (ICBT), two left bronchial arteries (40.6%). Type II: one on the right from ICBT, one on the left (21.3%). Type III: has two from the right (one from an ICBT) and two from the left (20.6%) Type IV : has two from the right (one from an ICBT) and one from the left (9.7%).

Fig 2: Non-enhanced CT axial image (A) of a 53-year-old male who presented with haemoptysis shows fibrosis and volume reduction of the left lower lobe. Axial and sagittal Contrast-enhanced CT images (B & C) and catheter angiogram (D) showed a left bronchial artery with orthotopic origin from the mid-thoracic aorta, which was subsequently embolised with PVA particles (E&F).

Fig 3: Non-enhanced CT axial images (A&B) of a 43-year-old male who presented with haemoptysis show fibrosis in the right upper lobe. Contrast-enhanced CT images (C&D) and catheter angiogram (E&G) showing the right bronchial artery and intercostal-bronchial trunk (red arrows in C&D) with orthotopic origin from the mid-thoracic aorta, which were subsequently embolised with PVA particles (F&G).

Fig 4: CT images (A-C) of a 22-year-old male who presented with recurrent episodes of haemoptysis and fever show bronchiectasis in the left upper lobe (A), patchy ground glassing opacities involving the right middle lobe (B) and a common bronchial artery originating from the mid-thoracic aorta (C), which was selectively cannulated (D) and embolised with PVA particles (E&F).

Uncommon Vascular Sources of hemoptysis

The uncommon vascular sources of hemoptysis can be divided into those arising from systemic and pulmonary circulations.

Fig 5: Table showing the classification of the atypical vascular sources of haemoptysis.

Fig 6: Diagram illustrating the various systemic and pulmonary sources of hemoptysis. A - orthotopic bronchial arteries arising at T5-T6 level, B - posterior intercostal arteries, C - vertebral artery, D - thyrocervical trunk, E - internal mammary artery, F - costocervical trunk, G - lateral thoracic artery, H - ectopic bronchial artery from the undersurface of the aortic arch, I - inferior phrenic artery from the abdominal aorta or as branches from the celiac axis, J - brachiocephalic artery pseudoaneurysm, K - descending aortic aneurysm, L - pulmonary sequestration with systemic supply, M - Rasmussen aneurysm, N - pulmonary embolism, O - pulmonary arteriovenous malformation

1. Systemic Sources:

1a. Ectopic bronchial arteries

Any bronchial artery that originates from locations other than the proximal descending aorta is referred to as an ectopic bronchial artery. The common vessels from which they arise include [4-7]:

1. Elsewhere along the aorta - aortic arch, abdominal aorta
2. Subclavian artery and its branches
3. Brachiocephalic trunk
4. Coronary artery (rarely)

Fig 7: CT images (A-C) of a 69-year-old male with a history of pulmonary tuberculosis, show a thick-walled cavity with a fungal ball in the left upper lobe and an ectopic bronchial artery arising from the undersurface of the aortic arch (yellow arrow in C). Selective catheter angiogram after cannulation of the ectopic bronchial artery was done (D) and was subsequently embolised with PVA particles (E&F).

Fig 8: CT images (A & B) of a 53-year-old male who presented with haemoptysis show bronchiectasis in the left lower lobe (A) and an ectopic bronchial artery arising from the proximal left subclavian artery (yellow arrow in B). Selective catheter angiogram after cannulation of the ectopic bronchial artery was done (C) and was subsequently embolised with PVA particles (D).

Fig 9: CT images (A-C) of a 49-year-old male with a history of pulmonary tuberculosis who presented with hemoptysis show fibrosis, volume loss, and traction bronchiectasis in the right upper lobe (A&B) and an ectopic bronchial artery arising from the proximal right subclavian artery (yellow arrow in C). Selective catheter angiogram after cannulation of the ectopic bronchial artery was done (D&E) and was subsequently embolised with PVA particles (F).

Fig 10: Axial and coronal CT images (A & B) of a 68-year-old female, with bronchial asthma, who presented with recurrent hemoptysis show cystic bronchiectasis in the left lower lobe. Contrast-enhanced CT image (C) and coronary angiography (D) revealed an ectopic bronchial artery originating from the left circumflex coronary artery and supplying to the aforementioned lesion (yellow arrows in C & D).

Ectopic bronchial arteries, akin to their orthotopic counterparts, eventually reach the hila, course along the bronchial tree and are deemed hypertrophied if their proximal diameter surpasses 2mm.

1b. Non-bronchial systemic collaterals

Non-bronchial systemic arteries develop in the setting of chronic hypoxia and inflammation in the lungs and are implicated in haemoptysis. They usually arise from [8]:

1. Subclavian artery and its branches
   • Internal mammary artery
   • Thyrocervical trunk
   • Costocervical trunk
   • Lateral thoracic artery
2. Intercostal artery
3. Branches of abdominal aorta
   • Inferior phrenic artery
   • Celiac trunk
4. Carotid and vertebral arteries
5. Coronary artery

Unlike ectopic bronchial arteries, non-bronchial systemic arteries do not follow bronchial anatomy and enter the lung parenchyma by traversing the pulmonary ligaments and pleural adhesions. The mere presence of these vessels is pathological, with no specific diameter threshold. CT may show associated pleural thickening and hypertrophy of the extra-pleural fat.

On catheter angiography, both ectopic bronchial and non-bronchial systemic arteries show:

1. Abnormal contrast blush in lung parenchyma
2. Vessel hypertrophy and tortuosity
3. Contrast extravasation (rarely)

Ectopic bronchial and non-bronchial systemic arteries are amenable to endovascular embolisation, with polyvinyl alcohol (PVA) particles (355–500 μm) being the recommended embolic agent [9].

Fig 11: CT images (A-D) of a 52-year-old female who presented with cough, fever, and hemoptysis show bilateral upper lobe disease with cavitation and fungal ball (A&B) and systemic arterial collateral arising from bilateral internal mammary arteries (red arrows in C&D). Selective catheter angiogram after cannulation of these arteries was done (E&G) and was subsequently embolised with PVA particles (F&H).

Fig 12: CT images of a 38-year-old male, a known case of recurrent tuberculosis who presented with multiple episodes of hemoptysis, show multiple irregular thick wall fibro-cavitary lesions in the bilateral upper lobes (A) and systemic arterial collaterals arising from bilateral thyrocervical trunks (red arrows in B&C). A selective catheter angiogram after cannulation of these arteries was done (D) and was subsequently embolised with PVA particles (E&F).

Fig 13: CT images (A&B) of a 43-year-old male with pulmonary tuberculosis who presented with haemoptysis show consolidation and cavitary changes in the superior segment of the right lower lobe with systemic arterial collaterals arising from the right intercostal artery (yellow arrow in B). Selective catheter angiogram after cannulation of the artery was done (C) and was subsequently embolised with PVA particles (D).

Fig 14: CT images (A&B) of a 42-year-old female who presented with cough, fever, and hemoptysis show volume loss of the left hemithorax with collapse-consolidatory changes (A) and systemic arterial collateral arising from the left inferior phrenic artery (yellow arrow in B). Selective catheter angiogram after cannulation of the artery was done (C) and was subsequently embolised with PVA particles (D).

Difficult configurations of the aortic arch, aortic arch variants, and tortuous anatomy of the aortic branches like the subclavian artery may pose challenges in the cannulation and embolisation of these vessels. Radial access may be an effective alternative in these scenarios.

Fig 15: CT (A&B) and VR (C) images of a 79-year-old female, who presented with hemoptysis, show fibrotic and emphysematous changes in bilateral upper lobes (A), type III aortic arch (B) and tortuous right subclavian artery (C), making the cannulation of the right internal mammary artery difficult via femoral approach. A catheter angiogram of the right subclavian artery shows exaggerated tortuosity (D). Hence the patient underwent an angiogram and embolization of the right internal mammary artery via radial approach (E&F).

Spinal cord infraction is the most feared complication of bronchial artery embolisation, which can also occur when embolising ectopic bronchial and non-bronchial systemic arteries. Therefore, particular care must be taken to identify segmental feeders to the anterior spinal artery, especially from the intercostal arteries.

Fig 16: CT image of a 63-year-old male who presented with massive hemoptysis shows patchy consolidation involving the right lung (A). The patient underwent embolisation of bronchial arteries and systemic arterial collateral arising from the left intercostal-bronchial trunk, after which he developed paraparesis. MRI spine was done (B-D) which revealed T2 signal hyperintensity (C&D) and diffusion restriction (E) from D2 to D7 levels involving the anterior cord suggestive of anterior spinal artery infarction. The catheter angiogram images were retrospectively analysed, which revealed segmental supply to the anterior spinal artery from the embolised left intercostal-bronchial trunk (E&F).

1c. Aneurysm/pseudoaneurysm of systemic arteries

Systemic arterial aneurysms and pseudoaneurysms are rare causes of haemoptysis. Aneurysm of any systemic vessel in proximity to the thorax, commonly the thoracic aorta and its branches, can result in haemoptysis. Pseudoaneurysms usually arise following infection, trauma or iatrogenic injury and are at an increased risk of rupture, as they are not contained by all layers of the vessel.

MDCT findings include:

1. Focal dilatation or saccular outpouching of vessel
2. Irregular wall (pseudoaneurysm)
3. Rounded or irregular focus of contrast material (in small lesions)
4. Contrast material extravasation (uncommon)
5. Direct contact with an airway - suggestive of artery-to-airway fistula

Endovascular treatment options depend on the size, shape, and location, and include:

1. Embolisation (coils, liquid embolic agents)
2. Stent graft placement
3. Thoracic endovascular aortic repair (descending thoracic aortic aneurysms)

Fig 17: Contrast-enhanced CT (A-C) images of a 77-year-old male who presented with fever and hemoptysis show a saccular pseudoaneurysm arising from the posterior wall of the brachiocephalic artery (red arrows in A&B) with venous phase showing peripheral non enhancing area with peripheral enhancement surrounding the pseudoaneurysm (red arrow in C) suggestive of mediastinal abscess. DSA images of the aortic angiogram of the patient show a pseudoaneurysm of the brachiocephalic artery (red arrow in D) for which a stent graft was placed (E) which resulted in the exclusion of the aneurysm (F).

Fig 18: CT images of a 46-year-old male, who presented with dysphagia and one episode of haemoptysis show aspirated blood in the form of centrilobular nodules with a tree in bud appearance in the right upper lobe (A), a large aneurysm with mural thrombus arising from the ascending aorta (B&C) abutting the tracheal bifurcation (red arrow in B). CT image of the patient post-surgical repair of the aneurysm (D).

1d. Systemic supply in sequestration

Pulmonary sequestration is a type of congenital bronchopulmonary vascular malformation in which the involved lung parenchyma is not connected to the bronchial tree or pulmonary arteries. It derives blood supply from systemic circulation, commonly from branches of the thoracic or abdominal aorta [10-12]. These patients may develop haemoptysis due to the higher systemic pressures of the feeding artery. Sequestration may be seen as part of scimitar syndrome, which also includes an anomalous right pulmonary venous return to the inferior vena cava [13].

Endovascular embolisation of the feeding systemic artery using coils or vascular plugs is the treatment of choice for hemoptysis in these patients [14].

Fig 19: CT images (A-C) of a 34-year-old male who presented with recurrent episodes of haemoptysis show multiple well-defined soft tissue density lesions in the right lower lobe in the posterior basal segment (A) with systemic arterial supply from a branch arising from the descending thoracic aorta suggestive of sequestration (red arrows in B&C). The patient underwent DSA with a selective angiogram of the systemic artery supplying the sequestered right lower lobe (D), followed by endovascular embolization with multiple coils (E) which resulted in complete occlusion of the feeding systemic artery (F).

Fig 20: Contrast-enhanced axial, coronal, and VR-CT images of an infant with Scimitar syndrome who presented with expiratory wheeze and hemoptysis show hypoplastic right pulmonary artery (red arrow in A), hypoplastic right lung with dextroposition of the heart (B). The right superior and inferior pulmonary veins are seen to drain into the IVC (yellow arrow in C&D), with systemic supply to the right lower lobe from a branch of the celiac trunk (red arrow in C&D). - s/o Scimitar syndrome.)

1e. Atypical configurations of bronchial arteries and non-bronchial systemic collaterals

Bronchial artery aneurysms and bronchopulmonary shunts may be rarely encountered during MDCTA and catheter angiography of bronchial and non-bronchial arteries in patients with hemoptysis. Notably, these patients tend to present with more severe episodes of hemoptysis.

Both of these conditions can be treated by endovascular embolisation of the diseased vessel using PVA particles. However, larger particles (700–900 μm) or coils are preferred in patients with bronchopulmonary shunts to avoid non-target systemic and pulmonary embolisation [9].

Fig 21: Axial and coronal CT images (A & B) of a 68-year-old male, a documented case of pulmonary tuberculosis, who presented with recurrent episodes of hemoptysis, shows fibrosis, cavitation, and traction bronchiectasis in bilateral upper lobes (A), with systemic arterial collaterals arising from the intercostal artery (yellow arrow in B). Serial angiographic images (C-E) obtained after selective cannulation of the artery show abnormal communication between these vessels and a branch of the pulmonary artery suggestive of bronchopulmonary shunt (yellow arrows in C-E), which was subsequently embolised with PVA particles (F).

Fig 22: CT images (A-C) of a 24-year-old female, with a history of pulmonary tuberculosis and presenting with hemoptysis, reveal the presence of a cavitary lesion with surrounding fibrosis in the left upper lobe and systemic arterial collaterals arising from the left intercostal artery (yellow arrows in B&C). Selective catheter angiogram after cannulation of the artery was done which showed broncho pulmonary shunt (D&E) and was subsequently embolised with PVA particles (E&F).

1f. Aortopulmonary Collateral Arteries

Aortopulmonary collaterals are embryologic connections from the aorta or its branches to the pulmonary arterial vasculature which persists to augment pulmonary blood flow. They are usually associated with several congenital heart diseases with compromised pulmonary blood flow, such as pulmonary atresia with ventricular septal defect and tetralogy of Fallot. Haemoptysis may occur as these vessels are at a higher systemic pressure [15].

The treatment modalities for MAPCAs include unifocalization, surgical ligation, and endovascular interventions, such as coil embolisation [15].

Fig 23: Contrast-enhanced CT images of a boy with tetralogy of Fallot who presented with exertional dyspnoea and haemoptysis show ventricular septal defect with overriding of the aorta (red arrows in A&B), subvalvular and valvular pulmonary stenosis (C) and multiple aorto-pulmonary collaterals arising from the thoracic aorta (red arrows in D). The aorto-pulmonary collaterals were subsequently embolised.

2. Pulmonary sources

2a. Pulmonary arteriovenous malformation (PAVM)

PAVMs are characterised by direct communication of the pulmonary artery with the pulmonary vein, devoid of the connecting capillaries. Patients may be asymptomatic or can present with dyspnoea, cyanosis, haemoptysis, stroke, and brain abscess [16].

PAVMs can be classified into simple or complex based on the number of feeding arteries. A simple PAVM is supplied by one feeding artery, whereas complex PAVMs have multiple feeding arteries. PAVM is a characteristic finding in patients with hereditary hemorrhagic telangiectasia or Osler-Weber-Rendu syndrome. These patients usually have complex and bilateral lesions

Transcatheter embolisation using coils or vascular plugs is the recommended intervention for these cases [17].

Fig 24: Contrast-enhanced CT images (A&B) of a 24-year-old male who presented with hemoptysis and desaturation show avidly contrast-enhancing serpiginous mass in the right middle lobe which is fed by multiple branches of the right pulmonary artery and drains into the right lower pulmonary vein (A&B) suggestive of complex pulmonary arteriovenous malformation(PAVM), with volume rendered image depicting the same (C). The DSA image shows the PAVM in the right middle lobe (D). The feeding pulmonary arteries were embolized using an Amplatzer vascular plug (E) resulting in complete occlusion of the PAVM (F).

Fig 25: Contrast-enhanced CT and VR images (A-C) of a 30-year-old female, who presented with dyspnea and hemoptysis, reveal an enhancing lesion in the left lingular segment supplied by multiple branches of the left pulmonary artery and draining into the left lower pulmonary vein (yellow arrows in A-C), suggestive of a complex pulmonary arteriovenous malformation (PAVM). A catheter angiogram shows the PAVM, the feeding pulmonary artery, and the draining pulmonary vein (D). The feeding pulmonary artery of the PAVM was embolised with an Amplatzer vascular plug (E), resulting in the complete closure of the PAVM (F).

Fig 26: Contrast-enhanced CT and VR images (A-C) of a young female with Hereditary hemorrhagic telangiectasia, who presented with dyspnea and hemoptysis, reveal bilateral pulmonary arteriovenous malformations (PAVM) (A&B) and multiple hepatic telangiectasias (C). A catheter angiogram shows a PAVM in the left lung (D). The feeding pulmonary artery of the PAVM was embolised with an Amplatzer vascular plug and coils (E), resulting in the complete closure of the PAVM (F).

2b. Pulmonary artery pseudoaneurysms (PAP)

PAPs are focal dilations of a segment of a pulmonary artery and are a rare cause of haemoptysis. They are commonly adjacent to foci of lung infection and can result in life-threatening hemoptysis [18]. Other rare causes include vasculitis, tumoral invasion, trauma, and iatrogenic injury. MDCTA is the imaging modality of choice for diagnosis.

Rasmussen's aneurysm is a type of PAP characterised by an inflammatory dilatation of a branch of a pulmonary artery adjacent to a tubercular cavity [19].

These lesions may be treated by endovascular embolisation using coils or liquid embolic agents [20].

Fig 27: CT images (A-C) of a 56-year-old male with pulmonary tuberculosis who presented with fever and hemoptysis show consolidation with cavitary necrosis in the lower lobe of the left lung (A). Focal dilatation of the segmental artery seen within the lesion, suggestive of Rasmussen's aneurysms (red arrows in B&C). DSA images of the left pulmonary angiogram depict the pseudoaneurysm (D) which was subsequently embolized (E) with N-butyl cyanoacrylate resulting in its complete occlusion (F).

2c. Pulmonary thromboembolism (PTE)

Patients with a PTE may present with haemoptysis secondary to pulmonary infarcts. Most clinically significant PTE originate from embolisation of venous thrombus in the lower extremities or pelvic veins.

MDCTA shows filling defects in the main pulmonary artery or its branches with features of pulmonary infarcts and hemorrhage in the lung parenchyma. Features of right heart strain in the form of right ventricular dilatation and reflux of contrast into the inferior vena cava may also be seen.

Catheter-directed thrombolysis and thrombectomy is an effective treatment option in haemodynamically unstable with PTE.

Fig 28: CT images (A & B) of a 28-year-old male who presented with shortness of breath, haemodynamic instability, and multiple episodes of haemoptysis show consolidation in the right upper lobe (A), with filling defects in the right pulmonary artery (B), suggestive of pulmonary thromboembolism. The patient underwent a pulmonary angiogram which confirmed these findings (C), followed by catheter-directed thrombolysis and thrombectomy which resulted in improved lung perfusion (D).