A radial artery originating from the thoracoacromial artery.

PURPOSE: The purpose of this case report is to report a rare vascular variation in the upper limbs because of its clinical importance and embryological implication. METHODS: During the educational dissection of a 73-year-old Korean male cadaver`s right upper limb, we found a variant branch which is originated from the thoracoacromial artery. RESULTS: The variant branch from the thoracoacromial artery ran to the distal forearm in the deep fascia. Because it finally coursed like the radial artery in the forearm and the palm, we defined the variant artery as superficial brachioradial artery (SBRA). In the cubital region a little below the intercondylar line, the brachial artery gave off a small communicating branch to SBRA, and continued as the ulnar artery. CONCLUSIONS: We reported this unique variation and discussed its clinical and embryological implication.

A rare conglomeration of neurovascular variations in the brachium-antebrachium: clinico-embryological elucidation.

During routine dissection in left upper limb in an elderly male cadaver, variations in the arterial and neural pattern were noticed. The undersized brachial artery divided terminally into radial and ulnar artery at a distance of 15.4 cm from the tip of coracoid process, proximal to its usual division in cubital fossa. Additionally, the superior and inferior ulnar collateral artery instead of arising from the brachial artery, emanated from ulnar artery. The course of the median nerve also deserves a brief mention as it crossed the brachial artery from medial to lateral side to position itself laterally in the midbrachium. Coursing further, it shifted from lateral to medial side over the ulnar artery in the distal third of arm, thus placing itself medial to ulnar artery in the cubital fossa. There was also a communication between a medial offshoot of the musculocutaneous nerve and the median nerve 3 cm from the bifurcation of the brachial artery. Although the variations in the origin, termination, course and branching pattern of upper limb vessels and nerves are well documented, but the multitude of disparity in morphology with confusing neurovascular assembly put together in the same limb denotes an outstanding case. An attempt has been made to correlate the present anatomical variations with embryological aspects. Moreover, the clinical inferences of such variations are discussed for planning, performing and analyzing invasive and noninvasive clinical procedures in this region.

Unilateral anomalous antebrachial vasculature--a clinico-embryological insight.

OBJECTIVES: An important and frequently reported arterial variant of the upper extremity is the superficial ulnar artery (SUA). Although SUA is not an uncommon variation, its presence should be detected timely as any surgical procedure in this region could put this unnaturally present superficial vessel to risk. Therefore, we sought to report this anomaly relating to the brachial arterial branching pattern. MATERIALS AND METHODS: Through the course of a usual instructive gross anatomy class an arterial variant of the brachial artery was noted. A scrupulous dissection was carried out and the specimen photographed. RESULTS: The present study reports the unilateral presence of abnormal branching pattern and disposition of antebrachial blood vessels. The brachial artery is seen to branch off into superficial ulnar artery (SUA) and usual radial artery. Interestingly, common interosseous artery (CIA) springs from the radial artery instead of the ulnar artery which is the usual case. CONCLUSIONS: Simple procedures such as venepuncture and intra arterial injections may become cumbersome and complication prone. The study is a humble attempt to caution the radiologists before interpreting angiographic films and the surgeons before performing reconstructions in this region.

An unusual ulnar artery: its embryological basis and clinical significance.

The principal arteries of the upper limb show a wide range of variation that is of considerable interest to orthopaedic surgeons, plastic surgeons, radiologists and anatomists. The superficial and high origin of the ulnar artery is a well known but rarely encountered abnormality. In a routine dissection of the left upper limb of an adult male cadaver, a superficial ulnar artery was noted. The ulnar artery had a high origin from the brachial artery in the proximal part of the arm and had a superficial course in the forearm. It had a normal termination in the hand. The common interosseous artery and radial artery arose as a terminal branch of the brachial artery at the level of neck of radius. The superficial position of the artery makes it more vulnerable to trauma, haemorrhage and intra-arterial injection but at the same time, more accessible for cannulation. The embryological basis and clinical significance of such course and origin has been explained.

Persistent median artery in the carpal tunnel: anatomy, embryology, clinical significance, and review of the literature.

The median artery usually regresses after the eighth week of intrauterine life, but in some cases it persists into adulthood. The persistent median artery (PMA) passes through the carpal tunnel of the wrist, accompanying the median nerve. During anatomical dissection in our department, we found two unilateral cases of PMA originating from the ulnar artery. In both cases the PMA passed through the carpal tunnel, reached the palm, and anastomosed with the ulnar artery, forming a medio-ulnar type of superficial palmar arch. In addition, in both cases we observed a high division of the median nerve before entering the carpal tunnel. Such an artery may result in several complications such as carpal tunnel syndrome, pronator syndrome, or compression of the anterior interosseous nerve. Therefore, the presence of a PMA should be taken into consideration in clinical practice. This study presents two cases of PMA along with an embryological explanation, analysis of its clinical significance, and a review of the literature. The review of the literature includes cases observed during surgical procedures or anatomical dissections. Cases observed by means of imaging techniques were not included in the study.

A rare case of bilateral variations of upper limb arteries: brief review of nomenclature, embryology and clinical applications.

We present a rare case of bilateral variations of upper limb arteries, namely, the superficial brachioulnoradial artery and the superficial brachioradial artery in a female cadaver. The superficial brachioulnoradial artery presented here is a variant of classical accounts. The superficial arteries replaced the typical arteries and were not additional vessels.

High origin of a superficial ulnar artery arising from the axillary artery: anatomy, embryology, clinical significance and a review of the literature.

The superficial ulnar artery (SUA) is an ulnar artery of high origin that lies superficially in the forearm. Its reported frequency ranges from 0.17% to 2%. During anatomical dissection in our department we observed a unilateral case of SUA in a 75-year-old white male human cadaver. It originated from the right axillary artery at the level of the junction of the two median nerve roots and followed a looping course, crossing over the lateral root of the median nerve and running lateral to it in the upper and middle thirds of the arm, whereas in the inferior third of the arm the SUA crossed over the median nerve and ran medially to it. In the cubital fossa, it passed superficially over the medial side of the ulnar aponeurosis and coursed subcutaneously in the ulnar side of the forearm superficially to the forearm flexor muscles. In the hand the SUA anastomosed with the superficial palmar branch of the radial artery, creating the superficial palmar arch. Additionally, it participated in the development of the deep palmar arch. The axillary artery, after the origin of the SUA, continued as the brachial artery and divided into the radial and common interosseous arteries in the cubital fossa. The normal ulnar artery was absent. No muscular or other arterial variations were observed in this cadaver. The embryological interpretation of this variation is difficult and it may arise as a result of modifications to the normal pattern of capillary vessel maintenance and regression. The existence of a SUA is undoubtedly of interest to the clinician as well as to the anatomist. This report presents a case of unilateral SUA along with a review of the literature, embryological explanation and analysis of its clinical significance.

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.

Superficial ulnar artery: embryology, case report, and clinical significance in reconstructive microsurgery.

In this paper the authors describe and illustrate a rare anatomic variation of the ulnar artery, a superficial ulnar artery. The possible embryologic events responsible for this variation are discussed. In addition, they describe the surgical considerations that should be kept in mind when this abnormality is encountered in the clinical setting of free-tissue transfer and vascularized nerve grafting.

An unusual variation of the superficial ulnar artery.

Anomalous superficial ulnar arteries were found bilaterally during routine dissection of the upper limbs of a 60-year-old male cadaver. In the left arm, the superficial ulnar artery originated from the axillary artery. It crossed the median nerve anteriorly and ran anteromedial to this nerve and the brachial artery. The superficial ulnar artery was also rudimentary and gave rise to only a narrow muscular branch to the biceps brachii. In the hand, it anastomosed with the radial artery, completing the superficial palmar arch. The radial artery was larger than usual and the deep palmar arch was formed only by the radial artery. In the right arm, the superficial ulnar artery originated from the brachial artery at the level of the inter-epicondylar line. Additionally there were "inverse palmaris longus muscles" bilaterally. This was a rare case in which the superficially ulnar artery originated from a different source on each side accompanied by anomalies of the palmar arches on one side.

An anatomical study and ontogenetic explanation of 23 cases with variations in the main pattern of the human brachio-antebrachial arteries.

Twenty-three cases with variations in the brachio-antebrachial arterial pattern of the human upper limb are reported. According to the artery which showed a variation, 4 groups were recognised: (1) isolated persistence of the median artery; (2) high origin of the ulnar artery; (3) high origin of the radial artery; and (4) duplication of the brachial artery, either with or without anastomosis at the cubital fossa. In addition, in groups 2, 3 and 4 the median artery may have persisted. Based on these arterial variations an anatomical and embryological correlation was established from a morphogenetic pattern which is proposed as being normal. Thus the terminal branches of the superficial brachial artery take part in the development of the radial, ulnar and median arteries, joining with the trunks of deep origin of these arteries in the primitive axial artery. Regression of the superficial arterial segments located proximal to this anastomosis gives rise to the definitive arterial pattern. Either the total or partial persistence of the superficial arterial segments explains those cases of high origin of either the radial or ulnar arteries as well as the duplications of the brachial artery. We postulate that the persistence of the median artery is independent of the presence or absence of any other variation in the arterial pattern.

Embryological development of the arterial system of the forelimb in Tupaia.

BACKGROUND: The arterial system of the upper extremities in man shows drastic developmental changes and many individual variations related to interspecific variations in primates. The ontogenetic development in Tupaia was examined from the viewpoint of comparative embryology. METHODS: Histological specimens of 39 embryos were observed and reconstructed in three dimensions using a computer program. Four adult animals were dissected and examined with angiography to ascertain the end stage of development. RESULTS: At the proximal end of the upper arm the deep brachial artery appears first as a concomitant vessel with the radial nerve. It becomes reduced in size and is succeeded by the posterior circumflex humeral artery, which is accompanied initially by the axillary nerve and finally by the radial nerve. The main arterial passageway to the fingers consists of the brachial and interosseous arteries during early development. The superficial brachial artery and median artery are formed later, and their connection becomes the main route of blood supply for the finger arteries up to the adult stage. The ulnar artery is formed at the end of arterial development to form the ulnar end of the superficial palmar arch. The superficial antebrachial arteries are also recognized. CONCLUSIONS: All the arterial elements of the forelimb in Tupaia are observed in a variety of primates, including man, and the characteristics of Tupaia are thought to represent the primitive conditions of the common ancestor of tree shrews and primates.