Background: The accessory brachial artery (arteria brachialis accessoria) is a rare upper limb vascular abnormality, reported in less than one percent of cases. It is the artery originating from the axillary artery or the brachial artery, which rejoins the brachial artery further along its distal course within the arm or cubital fossa. Its detailed knowledge is necessary in transradial transulnar catheterization during coronary procedures, mainly due to its narrow caliber, which is responsible for the failure of the intervention performance.
Objectives: Present a case of uncharacteristic branching pattern of the accessory brachial artery.
Method: The case was observed during a routine dissection in the left axilla of a female cadaver at the Department of Anatomy at the Third Faculty of Medicine, Charles University in Prague.
Results: The infrapectoral part of the axillary artery gave rise to a branch that descended distally along the medial side of the arm. This artery accompanied firstly the ulnar nerve, then it diverted laterally towards the median nerve and coursed hidden behind it to re-enter the brachial artery within the distal part of the arm, next to the biceps brachii muscle. The calibre of the accessory brachial artery was two mm only.
Conclusion: The accessory brachial artery is a rare variant of the upper limb vascular system and its prevailingly narrow lumen can cause a failure of the transradial/transulnar catheterization intervention.