We appreciated the paper of Recalde-Zamacona et al., entitled: Bronchial Artery Pseudoaneurysm and Mediastinal Hematoma after EBUS-TBNA.1 The authors have well illustrated the first case of bronchial artery pseudoaneurysm as complication of Endobronchial Ultrasound-Transbronchial Needle Aspiration (EBUS-TBNA) treated by the endovascular embolization. Only limited numbers of cases of bronchial artery aneurysm and pseudoaneurysm have been described in literature using endovascular approaches without an indication/guide line of the various techniques available.1,2
Bronchial artery aneurysm and pseudoaneurysms are a very rare vascular event, but potentially life-threatening.1–3 So, they must be treated as quick as possible in urgent setting. Iatrogenic, vascular wall trauma and inflammation are the main etiologies of bronchial artery aneurysm and pseudoaneurysm.1–3 Nowadays, endovascular approach is considered the first-line method for most aortic branch artery pathology; as performed by Recalde-Zamacona et al. with endovascular embolization in one of the few cases of bronchial artery pseudoaneurysm described in the literature.1–5 Skills in endovascular procedures and good knowledge of materials are mandatory to approach these challenging clinical situations. The various endovascular techniques can be applied individually or in combination with each other, since every case can be different from the other.1–5 Aim of our editorial is to complete and to give a possible indication of the three possible endovascular therapeutic techniques for bronchial artery aneurysm and pseudoaneurysm: (a) isolation embolization, (b) packing embolization and (c) stenting deployment.
- a)
Isolation embolization technique characterized by the complete embolization of efferent (distal) and afferent (proximal) branch arteries of the aneurysm or pseudoaneurysm sac. This method is generally the most commonly used. It is performed when the aneurysm or pseudoaneurysm sac involves the distal tract of the bronchial artery and has multiple vessels involved. Generally coils and micro-plugs are used as embolized agents. But for smaller and distal terminal vessel micro-particles or liquid embolized agents are used. Isolation embolization technique is equivalent to surgical vascular ligation. The main disadvantage of this technique is that occlude the treated artery segment with blood flow interruption. But, the possible risk of ischemic lesion of downstream territory is very low due artery vascular compensation network over time by bronchial, intercostal and mammary collateral artery vessels.3–5
- b)
Packing embolization technique is characterized by filling the aneurysm or pseudoaneurysm sac by metallic coils or liquid embolization agent device. This method can be performed only when the aneurysm or pseudoaneurysm sac involves a straight tract of the bronchial artery without collateral branches and it has a small neck, which guarantees the absence of migration out of the embolized agent from the sac into the main bronchial artery segment. The main advantage of this technique is that guarantee patency of the bronchial artery treated segment.3–5
- c)
Stenting deployment technique, using covered or flow-diverter devices, has the same aim packing embolization of guarantee aneurysm or pseudoaneurysm sac exclusion and to ensure blood perfusion to distal bronchial artery branch vessels. This type of endovascular approach is more theoretical than practical due to two main limitations: tortuosity and small size of bronchial artery that can limits the navigability of stent device, and the need of an adequate bronchial artery distal and proximal neck for stent deployment (no always present).
The main limitation of endovascular embolization is the subsequent imaging follow-up, especially with Multi Detector Computed Tomography (MD-CT). On MD-CT especially coils or high-density liquid embolic devices create artifacts, which may not highlight a possible endoleak at the level of the treated bronchial artery segment. In these case angiography has to be used to evaluate treated aneurysm or pseudoaneurysm over time.
In conclusion, patients affected by bronchial artery aneurysm or pseudoaneurysm are very rare.1 But this potentially life-threatening pathology needs an appropriate multidisciplinary discussion having attention on pseudoaneurysm anatomical location, characteristics, extension, and patient's hemodynamic status to determine the specific treatment for each individual case.
Conflicting interestAuthors do not has any conflicts of interest, financial or otherwise, relating to the content here.