Ectopic origin of bronchial arteries: still a potential pitfall in embolization

Purpose To evaluate the influence of ectopic origin of bronchial arteries (BAs) on bronchial artery embolization (BAE) for hemoptysis. Methods CT and angiography images of 50 consecutive sessions in 39 patients (aged 26-93 years; mean, 70.6 years) who underwent BAE for hemoptysis from April 2010 to December 2019 were reviewed. We defined ectopic BA as a systemic artery originating from other than the T5-T6 vertebral level of the descending aorta with course along the major bronchi. The background of patients, number of BAs, culprit arteries, and treatment outcomes were compared between the cases with and without ectopic BAs. Results Seventeen patients (43.6%) demonstrated 19 ectopic BAs, originating from the subclavian artery (n = 7), aortic arch above the T5-T6 level (n = 6), internal mammary artery (n = 3), brachiocephalic trunk (n = 2) or lower descending thoracic aorta (n = 1). Total number of BAs in the cases with ectopic BA was significantly greater than those in cases without ectopic BA (p = 0.0062). Required sessions of embolization were similar in the two groups. No procedure-related significant complications were noted; however, four ectopic BAs caused unexpected filling of contrast media or migration of the embolic material from the orthotopic BA to ectopic BA originating from the arch vessels via tiny communication. Conclusion Although BAE under the presence of ectopic BA is feasible and safe, detection of BAs with ectopic origin, even of small diameter, is needed to avoid risk of non-target coursing of embolic materials.