Arteries transport blood away from the heart and they vary in size. The arteries consist of three layers: tunica adventitia, tunica media and tunica intima. Arteries normally stretch easily or have high compliance with small increases in pressure due to the presence of elastic fibres (Tortora and Derrickson [243]). The brachial artery terminates as the radial and ulnar arteries, and an extensive collateral network of superficial and deep palmar arteries connects the radial and ulnar circulations. This normal pattern is present in 84% of patients. In 5% of cases, the radial artery is derived from the superficial brachial artery while the ulnar and interosseous arteries continue to originate from the brachial artery (Brzezinski et al. [25]).