Thoracic · IR Playbook

Bronchial Artery and Nonbronchial Systemic Artery Embolization (BAE/NBSAE)

Bronchial artery and nonbronchial systemic artery embolization is the first-line endovascular treatment for life-threatening or recurrent hemoptysis arising from the systemic circulation. It combines superselective embolization of abnormal bronchial arteries with an active search for ectopic bronchial and nonbronchial systemic collaterals, which are important causes of technical failure and recurrence. Contemporary pooled technical and immediate clinical success rates are approximately 97% and 93%, respectively, although recurrent hemoptysis remains common because of incomplete embolization, recanalization, collateral recruitment or progression of the underlying disease.

Learning objectives

• Differentiate orthotopic and ectopic bronchial arteries from nonbronchial systemic arteries on CT angiography and catheter angiography.
• Recognize angiographic targets including arterial hypertrophy, tortuosity, hypervascularity, systemic-to-pulmonary shunting, extravasation and pseudoaneurysm.
• Perform superselective embolization while protecting spinal, cerebral, coronary, esophageal and other critical arterial branches.
• Select an embolic agent according to vessel anatomy, shunt severity, bleeding mechanism and likelihood of future reintervention.
• Identify causes of persistent or recurrent hemoptysis after technically successful systemic arterial embolization.

Indications

• Life-threatening hemoptysis, defined by airway obstruction, respiratory failure or hemodynamic instability rather than by an arbitrary expectorated blood volume.
• Moderate hemoptysis, commonly considered approximately 100–300 mL in 24 hours, particularly when ongoing or associated with reduced respiratory reserve.
• Recurrent or chronic hemoptysis that interferes with daily activities, causes anemia or persists despite appropriate treatment of the underlying disease.
• Hemoptysis from post-tubercular sequelae, bronchiectasis, chronic pulmonary aspergillosis, active infection, malignancy, cystic fibrosis, trauma or systemic-to-pulmonary vascular shunts.
• CTA or bronchoscopy demonstrating a high-risk vascular lesion such as a bronchial artery aneurysm, pseudoaneurysm or hypertrophied systemic arterial supply.
• Recurrent hemoptysis after previous embolization, with reassessment for recanalized arteries, missed ectopic bronchial arteries and newly recruited nonbronchial systemic collaterals.

Absolute contraindications

• A target artery supplying the spinal cord, brain or heart when the critical branch cannot be safely bypassed or protected.

Relative contraindications

• Severe uncorrectable coagulopathy or thrombocytopenia, balanced against the urgency of life-threatening hemorrhage.
• Severe iodinated-contrast hypersensitivity when adequate premedication or an alternative strategy is not possible.
• Severe renal dysfunction, especially when extensive angiography is anticipated; minimize contrast and proceed if the lifesaving benefit outweighs the risk.
• Unprotected airway in a patient with active life-threatening bleeding; airway stabilization should occur concurrently and must not unnecessarily delay embolization.
• Extensive systemic-to-pulmonary or systemic-to-systemic shunting that cannot be controlled using larger particles, coils or another protective strategy.

Equipment

• Ultrasound-guided arterial access set with 21 G micropuncture needle, 0.018-inch wire and 4–6 Fr introducer sheath.
• 4–5 Fr diagnostic catheters selected for anatomy: RDC, Cobra 1 or 2, Simmons 1, shepherd hook, multipurpose, Mikaelsson, vertebral or internal mammary catheter.
• Optional 5–6 Fr long guiding sheath or guide catheter for arch vessels, tortuous aorta or unstable catheter position.
• 2.0–2.8 Fr, 130–150 cm microcatheter compatible with the intended embolic agent.
• 0.014–0.021-inch steerable hydrophilic microwires and a 0.035-inch hydrophilic guidewire.
• 300–500 μm PVA particles or calibrated microspheres as the usual particulate embolic; 500–700 μm or larger particles for significant systemic-to-pulmonary shunting.
• Detachable or pushable microcoils sized approximately 20–30% larger than the target artery for pseudoaneurysm, protection of a critical branch or selected high-flow shunts.
• NBCA with iodized oil and 5% dextrose for experienced operators requiring durable distal embolization or treatment of recanalized, tortuous or rapidly flowing vessels.
• Gelfoam slurry for selected temporary embolization when a permanent agent is unsuitable, recognizing the higher potential for recanalization.
• Nonionic iodinated contrast, pressure tubing, three-way stopcocks, 1–10 mL syringes and heparinized saline for catheter flushing.
• Digital subtraction angiography with road-mapping and optional cone-beam CT for difficult culprit-vessel localization.

Procedure steps

1. Secure oxygenation, venous access and blood products and obtain airway control when indicated. Correlate the bleeding side from CTA, bronchoscopy and chest radiography, and position the bleeding lung dependently when feasible.Pearl: Hemoptysis is usually fatal through asphyxiation rather than exsanguination; airway protection takes priority.
2. Map every orthotopic and ectopic bronchial artery, suspicious nonbronchial systemic collateral and pulmonary arterial abnormality. Note pleural thickening, extrapleural vessels, prior coils and potential spinal, vertebral or coronary communications.Pearl: CTA reduces blind catheter searching, radiation exposure and contrast use and improves identification of ectopic and nonbronchial sources.
3. Use ultrasound guidance to obtain common femoral or radial access and place a 4–6 Fr sheath. Select access according to the dominant arterial origins identified on CTA.
4. Use a shaped 4–5 Fr catheter to select CTA-mapped bronchial arteries, beginning with the suspected bleeding side. A flush thoracic aortogram may be used when CTA is unavailable or the origins cannot be identified, but is not routinely necessary after diagnostic-quality CTA.Pearl: Orthotopic bronchial arteries are sought around T5–T6, with the right intercostobronchial trunk commonly arising from the posterolateral aorta.
5. Inject gently under DSA and assess arterial size, tortuosity, parenchymal blush, neovascularity, shunting, extravasation and pseudoaneurysm. Examine the entire run for spinal, esophageal, coronary or other critical branches.Pearl: A pathologic blush or shunt is far more common than active contrast extravasation.
6. Advance a coaxial microcatheter into the abnormal bronchial branch and, when present, beyond the origin of any spinal or other critical branch. Confirm a stable free-flow position with a repeat microcatheter angiogram before embolization.Pearl: Superselective catheterization reduces nontarget embolization and preserves uninvolved bronchial and mediastinal branches.
7. Slowly inject well-suspended 300–500 μm particles under continuous fluoroscopy, pausing to prevent sedimentation and reflux. Use larger particles when a significant systemic-to-pulmonary shunt is present. Stop at marked slowing or near-stasis with disappearance of abnormal blush and shunting.Pearl: Periodic small contrast checks can reveal a spinal or other branch that becomes visible after redistribution of flow.
8. Assess other bronchial arteries supplying the involved lung and clearly abnormal contralateral arteries when disease is bilateral. Treat all safe contributors rather than relying on a single culprit artery.
9. Select CTA-suspicious subclavian, internal thoracic, intercostal, inferior phrenic, thyrocervical, costocervical, lateral thoracic and other systemic arteries. Confirm that the vessel reaches the pulmonary lesion through pleural or extrapleural pathways rather than following the bronchial tree.Pearl: Nonbronchial systemic arteries should be actively sought during the initial procedure when CTA shows pleural disease or extrapleural vascularity.
10. Advance the microcatheter as close as safely possible to the pulmonary target and beyond branches supplying chest wall, diaphragm, spinal cord, upper limb or abdominal viscera. Embolize using particles, NBCA or coils selected according to vessel caliber, shunting and the required level of occlusion.Pearl: For an intercostal artery, embolize only after excluding a radiculomedullary branch and achieving a distal stable position.
11. For a bronchial or nonbronchial pseudoaneurysm, exclude the lesion with distal and proximal coils when anatomy permits or use carefully controlled NBCA. For rapid systemic-to-pulmonary shunting, use larger particles and consider coil protection before particulate or liquid embolization.Pearl: NBCA may provide durable distal occlusion in recurrent or recanalized vessels but should be used only by operators experienced with dilution, catheter preparation and reflux control.
12. Perform a final selective angiogram showing elimination or marked reduction of abnormal hypervascularity and shunting without nontarget occlusion. Remove the catheter and sheath and obtain hemostasis by manual compression, radial compression device or an appropriate closure device.Pearl: Document every embolized artery, embolic agent and size, endpoint, residual abnormal arteries and any visualized critical branches.

Complications

• Transient chest or back pain, approximately 24–91%
• Transient dysphagia, approximately 0.7–18%
• Spinal cord ischemia or infarction, approximately 0.19% in a large nationwide study
• Cerebral or coronary nontarget embolization, very rare
• Bronchial or esophageal ischemia and necrosis, rare
• Pulmonary infarction or systemic embolization through a shunt, rare
• Arterial access complication
• Recurrent hemoptysis, approximately 10–50% or higher with long follow-up

Exam pearls

• Life-threatening hemoptysis is defined physiologically by airway, respiratory or hemodynamic compromise, not solely by blood volume.
• Orthotopic bronchial arteries arise between T5 and T6; an origin outside this range is ectopic.
• The right bronchial artery most commonly arises as part of an intercostobronchial trunk.
• Pleural thickening greater than 3 mm with extrapleural enhancing vessels predicts nonbronchial systemic supply.
• Absence of a spinal artery on the initial angiogram does not guarantee safety, because it may appear after flow redistribution.
• The usual particulate embolic size is 300–500 μm; avoid routine use of particles smaller than 300 μm.
• Do not wait for active extravasation: abnormal hypertrophy, blush, neovascularity or shunting is sufficient.
• Persistent bleeding after complete systemic embolization mandates evaluation of the pulmonary arterial circulation, particularly for a Rasmussen aneurysm.

Viva questions

What is the commonest arterial source of life-threatening hemoptysis?

Approximately **90% arises from the bronchial circulation** because hypertrophied bronchial arteries are exposed to systemic pressure. Pulmonary arteries and nonbronchial systemic arteries account for most remaining cases.

How do you distinguish an ectopic bronchial artery from a nonbronchial systemic collateral?

An ectopic bronchial artery has an origin outside the T5–T6 level but follows the bronchial tree toward the hilum. A nonbronchial systemic artery enters through pleural adhesions, extrapleural tissues or the pulmonary ligament and does not parallel the bronchi.

What CT findings predict a nonbronchial systemic arterial supply?

**Pleural thickening greater than 3 mm** adjacent to the pulmonary lesion and tortuous enhancing vessels in hypertrophied extrapleural fat are classic predictors. Asymmetric enlargement of an intercostal, internal thoracic or other systemic artery is another clue.

What angiographic abnormalities indicate embolization?

Hypertrophy, tortuosity, abnormal parenchymal blush, neovascularity, systemic-to-pulmonary shunting, active extravasation and aneurysm or pseudoaneurysm are indications. Extravasation is uncommon and is not required.

What is the preferred particle size for bronchial artery embolization?

**PVA particles or calibrated microspheres of 300–500 μm** are commonly used. Larger particles such as 500–700 μm are preferred when a significant systemic-to-pulmonary shunt is present; particles smaller than 300 μm are not routinely recommended.

How do you prevent spinal cord infarction during BAE?

Review CTA, perform careful selective angiography, identify radiculomedullary branches, advance the microcatheter beyond their origin and repeat angiography as flow changes. Never inject particles or liquid embolic when a spinal branch cannot be safely bypassed.

Why are coils not routinely used for every bronchial artery?

Proximal coil occlusion may prevent future distal access despite persistent collateral supply and can complicate repeat embolization. Coils are best reserved for pseudoaneurysm, selected high-flow shunts, protection of a critical branch or other specific anatomy.

What are the main causes of recurrent hemoptysis after BAE?

Early recurrence results from incomplete embolization, a missed ectopic or nonbronchial artery or an untreated pulmonary arterial source. Late recurrence results from recanalization, recruitment of new collaterals and progression or reactivation of the underlying disease.

References