the bronchial arterial circulation is the source of bleeding in nearly 90% of cases of massive hemoptysis . bronchial artery embolization ( bae ) has become an established procedure for the treatment of massive hemoptysis with proven efficacy and safety . a thorough knowledge of bronchial artery anatomy , including the possible locations of anomalous origin , is an integral component of a successful procedure . the anatomy of the bronchial arteries has been previously reported in considerable detail , outlining variations in origin , course , and branching pattern . we report a case of a common trunk bronchial artery arising from the left vertebral artery and review standard and variant bronchial artery anatomy relevant to complete evaluation of the bronchial arterial supply . an 89-year - old female with a past medical history of hypertension and chronic obstructive pulmonary disease presented to the emergency department with new onset of dizziness and gait instability that had been progressive over the prior 7 months . she was admitted to the neurology service , and during her evaluation for these complaints , she developed symptoms of shortness of breath , tachycardia , and chest fullness . computed tomographic pulmonary angiography ( cta ) was performed for evaluation of pulmonary embolism using a 16-detector scanner ( lightspeed 16 , ge medical systems , milwaukee , wi ) . images through the thorax were acquired at 1.25 mm collimation ( 120 kvp , 441 ma , pitch 1.375:1 , rotation time 0.8s ) after bolus tracking at the main pulmonary artery during the administration of 100 ml of iopamidol nonionic contrast media ( isovue 370 , bracco diagnostics inc . ) at 5 ml / s . while pulmonary embolism was not present , incidental finding was made of an anomalous bronchial artery arising from the proximal aspect of a left vertebral artery originating from the aortic arch between the left common carotid and left subclavian arteries [ figures 1a  c ] . this single bronchial artery arose from the right posterior aspect of the left vertebral artery approximately 1.5 cm distal to the aortic arch . the bronchial artery coursed along the left aspect of the trachea prior to bifurcating into right and left bronchial arteries approximately 1 cm above the carina . single bronchial arteries then coursed along the bilateral mainstem bronchi until subdividing into smaller tributary branches distally . no additional bronchial arteries were identified despite meticulous review of the source axial , reconstructed multiplanar , and 3d volume rendered images [ figure 2a  c ] . ( a ) a common trunk anomalous bronchial artery arises from the left vertebral artery . ( c ) bifurcation of the bronchial artery into left and right branches , which supply the respective lungs . ( a ) curved multiplanar reconstruction demonstrates the course of the bronchial artery within the mediastinum . ( b ) 3d volume rendered image demonstrates origin of the bronchial artery from the left vertebral artery ( the right brachiocephalic artery has been excluded ) . ( c ) note the close approximation of the bronchial artery with the adjacent tracheobronchial tree . [ lsca : left subclavian artery ; lcca : left common carotid artery ; l vertebral art : left vertebral artery ; rbca : right brachiocephalic artery ] . secondary to this finding the possibility of steal phenomena was explored via transcranial doppler evaluation , which was negative . an etiology for the patient 's neurological symptoms was not identified and the patient was discharged and advised outpatient physical and occupational therapy . numerous earlier investigations have evaluated the anatomy of the bronchial arteries describing variation in their origin , branching patterns and course . the bronchial arteries most commonly arise from the descending thoracic aorta between the lower margin of the t4 vertebral body and the upper margin of the t6 vertebral body ( 70  83.3% ) . the reported incidence of anomalous bronchial arteries varies widely , ranging from 8.3 to 35% . in 1948 , caudwell et al reported their anatomical findings after dissection of 150 human cadavers . this landmark study revealed 25 anomalous bronchial arteries ( 16.7% ) , 22 arising directly from the aortic arch ( 14.7% ) , 1 from the right subclavian artery , and 2 from the left subclavian artery . a review of the literature demonstrates general agreement with these initial findings , with an anomalous origin from the aortic arch being most common and an origin from the subclavian arteries second most common . since caudwell et al 's initial extensive study , anomalous bronchial arteries have also been reported to arise from the thyrocervical trunk , internal mammary artery , costocervical trunk , lateral thoracic artery , and the inferior aspect of the descending thoracic aorta.[39 ] additionally , battal et al recently described the origin of an anomalous bronchial artery from the right coronary artery via multidetector computed tomography ( mdct ) [ table 1 ] . reported anomalous bronchial arteries mdct angiography is a proven method for the evaluation of the bronchial arteries . in their retrospective study comparing conventional angiography with thin - section mdct angiography , remy - jardin et al found concordant identification of the number and origin of bronchial arteries in 86% of cases . use of mdct angiography prior to attempted bae may provide assistance in directing selective catheterization , particularly in the setting of an anomalous origin of the bronchial arteries , possibly reducing procedure time . further , mdct has the added benefit of providing an opportunity to identify non - bronchial artery bleeding sources such as non - bronchial systemic arteries , bronchiectasis , bronchogenic carcinomas , and aspergillomas . the normal adult bronchial arteries measure less than 1.5 mm in diameter at their origin and 0.5 mm at their point of entry into a bronchopulmonary segment . abnormal or hypertrophic bronchial arteries measure greater than 2 mm in diameter on mdct . we believe that this case represented a true bronchial artery , rather than a non - bronchial systemic collateral artery for several reasons . first , the 1-mm vessel diameter is well within the normal range for a native bronchial artery . second , there was no evidence of pleural thickening , significant pulmonary disease , or associated systemic collateralization to suggest that this vessel had arisen secondary to an underlying pathologic process . third , the patient had no prior history of bronchial artery embolization that would have lead to the recruitment of abnormal collateral vessels . finally , and most importantly , this vessel coursed along the tracheobronchial tree , which is the main distinguishing characteristic of a bronchial artery [ figure 2c ] . a complete knowledge of bronchial artery anatomy , including the locations of their common aberrant origin , is a prerequisite for successful complete angiographic assessment of the bronchial artery distribution as well as for successful embolization procedures . failure to identify a causative bronchial artery arising from the descending aorta should prompt a search for an aberrant origin , including an evaluation of the aortic arch and of the bilateral subclavian arteries and their branch vessels . in light of the case presented here , consideration of an origin from the vertebral artery should be entertained in cases of persistent failed identification .
knowledge of bronchial artery anatomy , including the possible locations of anomalous origin , is essential for complete catheter directed embolization for massive hemoptysis . 
 undetected anomalous bronchial arteries can be a source of failed bronchial artery embolization . 
 we report a case of a common trunk bronchial artery arising from the left vertebral artery and review standard and variant bronchial artery anatomy .