In this study, the evaluation of 233 patients who underwent BAE to treat non-massive hemoptysis revealed that BAE is a safe and feasible treatment, a high technical and clinical success rate with low major complication rate. Before BAE, bronchoscopy and/or contrast-enhanced CT examinations were performed to identify the underlying cause and extent of pulmonary diseases, localize possible bleeding foci, and predict the culprit vessels (19). Contrast-enhanced CT examinations were common for diagnosis (95.3%), possibly explaining the high technical success rate. These results are consistent with several studies on BAE (3–9, 13, 19–30), in which the technical success rate ranged from 81 to 100%. In our study, technical failure of BAE occurred in 9 patients whose angiographic catheter could not be inserted into the target arteries due to stenosis of the orifice. Only 1 patient did not clinically improve after BAE due to aberrant arterial supply to the lungs following recruitment of systemic blood supply and chronic inflammation. Previous studies have reported technical failure associated with incomplete embolization of existing arteries, recanalization of embolized arteries, and development of additional collateral blood supply (2, 31).
Various diseases such as pulmonary tuberculosis, bronchiectasis, and lung cancer may cause non-massive hemoptysis, with the geographic location of patients being an influential factor on the hemoptysis cause. For instance, regions of the world with an endemic burden of tuberculosis render it the main cause of hemoptysis. In fact, tuberculosis is the predominant cause of hemoptysis worldwide. In our study, the most frequent cause of non-massive bronchial bleeding was also tuberculosis, being consistent with other studies (27, 30, 32). Furthermore, we found that tuberculosis sequelae and active tuberculosis were significantly related to recurrent bleeding. Therefore, recurrent hemoptysis tends to occur more frequently in tuberculosis patients.
Recurrent bleeding after adequate embolization remains a considerable problem, occurring in 12–57% of patients (3). In our study, rebleeding occurred within 197 days (median) in 27.5% of the patients. A second BAE was performed in 42 patients, with 5 (11.9%) patients presenting rebleeding in the previous bleeder, whereas the others presented bleeding in other arteries, such as non-bronchial systemic collaterals. In 37 patients, additional bronchial or non-bronchial systemic collateral arteries were embolized, resulting in the successful control of hemoptysis, and 5 patients developed recanalization of the previously embolized vessels and underwent surgery. In patients with recurrent hemoptysis, tuberculosis sequelae and active tuberculosis were significantly common etiologies. The success of repeated treatment further indicates the effectiveness of BAE.
Interventional radiologists should be familiarized with prognostic factors related to recurrent bleeding. Early recurrent bleeding, within the first weeks and months after embolization, is caused by incomplete embolization of the abnormal vessels, possibly due to the extensive nature of the underlying disease or incomplete search for all abnormal vessels (5, 25, 26, 28, 30). Advances in embolic materials have improved technical success, and the overall recurrence rates have not significantly changed since the 1970s (2, 22). Thus, there is no consensus on the best embolic material for BAE. For the cases analyzed in this study, various embolic materials were used to perform BAE. In earlier years (2005–2008), Gelfoam-based embolic materials were predominant. In 2009–2012, PVA-based embolic materials were preferred, whereas NBCA-based embolic materials were mostly used after 2013. Gelfoam or PVA particles were most frequently used because they are easy to handle and inexpensive. Recently, the use of NBCA has been related to a significantly lower rate of recurrent bleeding, and there are more reports on the use of the liquid embolizing agent NBCA for BAE. This trend may be explained by various factors. Rapid and complete occlusion of the target vessels improves the effectiveness of embolization and reduces the procedural and fluoroscopic time, and the adjustable ratio of NBCA to iodized oil allows controlling the level of embolization within target vessels and the polymerization time (33, 34). In addition, the use of NBCA enables both complete occlusion of the target artery and filling of the adjacent potential collateral vessels (19). Therefore, more complete embolization is expected in hemoptysis, which usually presents multiple collateral vessels. The use of NBCA-based embolic materials significantly reduced recurrent bleeding events (p < 0.05) in the patients of our study.
Several limitations of this study deserve mention. First, this retrospective study only considered data from a single center, with uncertain homogeneity of data and a specific patient cohort. Nevertheless, the independent review of the database of the department of intervention radiology by three experienced radiologists improved data reliability. Furthermore, 233 consecutive patients from a single center can reduce the bias from possible confounding factors. Randomized controlled trials or prospective studies are needed to confirm the benefits of BAE in patients with non-massive hemoptysis. Second, the embolic material was selected at the discretion of the attending interventional radiologists. Therefore, the reasons for selection remain unclear, possibly biasing the results. Finally, the etiology of hemoptysis may vary among different countries, and caution is required if generalizing our results to different conditions.