An unusual branching pattern of the superficial brachial artery accompanied by an ulnar nerve with two roots

Case report of a new variant of double incomplete superficial palmar arch

A rare, unique and previously non-described form of duplicated incomplete superficial palmar arch is reported in the right hand of a male cadaver. The two incomplete arches were formed from the continuation of two terminal palmar branches of the ulnar artery in the distal third of forearm that were connected by a small transverse artery superficial to the flexor retinaculum. Both arches had no contribution from the radial artery. The palmar digital branches from the lateral arch supplied the lateral two-and-a-half fingers, while those from the medial arch supplied the medial two-and-a-half fingers. The thumb and index had additional blood supply from the princeps pollicis and radialis indicis branches of radial artery. The deep palmar arch was entirely formed by the radial artery with no contribution from the ulnar artery. Previous reports on various patterns of superficial palmar arch are highlighted, and the anatomical and clinical importance of the new pattern are discussed.

Variations of the superficial brachial artery in Korean cadavers

The superficial brachial artery (SBA), a branch of the axillary artery, is one of the most common arterial variations in this area. While it is more vulnerable to accidental arterial injection or injury, it could be useful for the nourishment of a medial arm skin free flap. To analyze the relationship between the SBA of axillary origin and segmental variation of the axillary artery, we dissected 304 arms of Korean cadavers. We found an SBA of axillary origin in 12.2% of cadaveric arms. Unilateral occurrence was detected in 16 cadavers and bilateral in 10. SBAs gave rise to radial and ulnar arteries in the cubital fossa (8.9%), continued in the forearm as the radial artery (2.3%), or ended in the upper arm (1.0%). The SBA ended as ulnar artery was not found in any of the cadavers. The bifurcation of the SBA into the radial and ulnar arteries, presence of an SBA that ends in the upper arm, and the lack of continuation as the ulnar artery are characteristics of SBAs in Korean cadavers.

Median nerve penetration by a muscular branch of the brachial artery

Arterial variations in the distal half of the arm are common (Anagnostopoulou and Venieratos 1999, J. Anat. 195:471-476). We observed a rare variant of a muscular branch of the brachial artery that penetrated the median nerve in the lower part of the arm. After its origin from the posteromedial surface of the brachial artery, the muscular branch passed through a nervous loop in the median nerve to enter and supply the brachialis muscle. At the site of arterial penetration, the nerve displayed perineurial thickening and increased fasciculation and interfascicular connective tissue. Three small branches of the artery supplied the nerve fascicles. We did not observe nerve compression or muscular changes, but the possibility of altered clinical symptoms produced by irritation from arterial pulsation cannot be ruled out. This variation may be clinically important because symptoms of median nerve compression arising from similar variations are often confused with more common causes, such as radiculopathy and carpal tunnel syndrome.

Unique case of trifurcation of the brachial artery: its clinical significance

The variability of the arteries in the upper extremity is considerable. This case is a report of a trifurcation of the brachial artery that divided into radial, ulnar, and superior ulnar collateral arteries high in the arm; the length of the brachial artery was only 4.9 cm. Because the upper extremity is a frequent site of injury, various surgical and invasive procedures are performed in this region; consequently, it is of utmost importance to be aware of arterial variations. For some medical procedures, there may be an increased risk of complications because of variant vessels; however, for other procedures, they may be beneficial. In addition to presenting a detailed anatomic study of the case, the clinical significance of the variation has been addressed.

Variations of the arterial pattern in the upper limb revisited: a morphological and statistical study, with a review of the literature

A total of 192 embalmed cadavers were examined in order to present a detailed study of arterial variations in the upper limb and a meta-analysis of them. The variable terminology previously used was unified into a homogenous and complete classification, with 12 categories covering all the previously reported variant patterns of the arm and forearm.

Development of the arterial pattern in the upper limb of staged human embryos: normal development and anatomic variations

A total of 112 human embryos (224 upper limbs) between stages 12 and 23 of development were examined. It was observed that formation of the arterial system in the upper limb takes place as a dual process. An initial capillary plexus appears from the dorsal aorta during stage 12 and develops at the same rate as the limb. At stage 13, the capillary plexus begins a maturation process involving the enlargement and differentiation of selected parts. This remodelling process starts in the aorta and continues in a proximal to distal sequence. By stage 15 the differentiation has reached the subclavian and axillary arteries, by stage 17 it has reached the brachial artery as far as the elbow, by stage 18 it has reached the forearm arteries except for the distal part of the radial, and finally by stage 21 the whole arterial pattern is present in its definitive morphology. This differentiation process parallels the development of the skeletal system chronologically. A number of arterial variations were observed, and classified as follows: superficial brachial (7.7%), accessory brachial (0.6%). brachioradial (14%), superficial brachioulnar (4.7%), superficial brachioulnoradial (0.7%), palmar pattern of the median (18.7%) and superficial brachiomedian (0.7%) arteries. They were observed in embryos belonging to stages 17-23 and were not related to a specific stage of development. Statistical comparison with the rates of variations reported in adults did not show significant differences. It is suggested that the variations arise through the persistence, enlargement and differentiation of parts of the initial network which would normally remain as capillaries or even regress.