We report a superficial brachioulnoradial artery (SBURA) presenting as a variant of the normal, originating from the proximal third of the right brachial artery of a 75-year-old female cadaver which bifurcated yielding a brachiointerosseous artery laterally and a SBURA medially, and the latter bifurcating 5 cm proximal to the elbow yielding a brachioradial artery laterally and the superficial brachioulnar artery medially, resulting in the formation of three instead of two brachial arteries as in the classical SBURA said to bifurcate at the elbow into the radial and ulnar arteries. Clinical implications of this variant are discussed.

In the chick embryo the paraxial mesoderm forms about 50-53 pairs of somites, the precise number depending on the extent to which segmentation proceeds along the tail. However, the terminal mesoderm of the tail fails to segment despite the fact that it appears to contain a reservoir of potential somites. Why does this mesoderm not segment? Some clues can be obtained by comparing this non-segmenting region with the segmental plate in the trunk. We and others have shown that in the trunk region of the chick, cell adhesion plays a major role in somitogenesis and that this increased cell adhesion is associated with compaction of segments of mesoderm immediately prior to segmentation. This compaction can be brought about prematurely by fibronectin and by the specific adhesion peptide GRGDS. The terminal mesoderm in the tail resembles the segmental plate mesoderm in the trunk in undergoing compaction in response to fibronectin and GRGDS. The tail mesoderm differs from the segmental plate mesoderm in that it can also respond to peptides closely related to GRGDS. The response suggests that, whereas the integrin receptors for fibronectin and GRGDS appear to be specific in the presomitic trunk mesoderm, responding only to the specific adhesion-peptide GRGDS, the tail mesoderm may contain more heterogeneous sets of receptors within the integrin/VLA family that respond to a wider variety of ligands. Coincident with these differences is the phenomenon of regional cell death in the tail bud mesoderm. All of these factors are thought to play a role in the extent of segmentation in the paraxial mesoderm of the embryonic chick.

SUMMARY: Vascular injuries of the lower limb, especially from penetrating gunshot wounds, and peripheral arterial diseases are on the increase and management of these and many other lower limb injuries involve increasing usage of vascular interventions like by-pass surgery, per-cutaneous transluminal angioplasty, arterial cannulation, arterial bypass graft or minimally invasive measures like percutaneous trans-arterial catheterization, among others. A thorough knowledge of infrapopliteal branching most especially their pathways and luminal diameters are important to surgeons in selecting appropriate surgical interventions or procedures. We report the case in which one of the 3 terminal branches of the popliteal artery (PPA), the anterior tibial artery (ATA) of good caliber size at origin became hypoplastic in the anterior leg region after giving off numerous muscular branches. Continuing as an almost attenuated dorsalis pedis artery (aDPA) in the dorsum of the foot, the latter was reinforced by an enlarged hypertrophied fibular artery. This case illustrates yet the importance of the fibular artery as the dominant of the 3 infrapopliteal branching arteries, reinforcing or replacing the posterior tibial artery (PTA) when it is weak or absent by a strong communicating branch or, reinforcing a weak ATA and dorsalis pedis artery (DPA) by a strong perforating fibular artery as being reported. The PTA however travelled a normal course yielding the medial and lateral plantar arteries posterior to the abductor hallucis muscle. This case demonstrates the importance of collateral communications and reinforcements from other infrapopliteal arteries, whenever one of its members or subsequent branches are absent or hypoplastic. A very sound knowledge of the various branching patterns of the PPA can be gained via pre-operatively vascular angiography, designed to guide the surgeon in the selection of appropriate surgical interventions, adding value to patients care in helping to reduce iatrogenic surgical vascular complications and reduction in total number of limb loss.

SUMMARY:Variants of the median nerve, extra forearm flexor muscles heads are relationships of the persistent median artery (PMA) that have been extensively reported. We report the findings of a PMA (diam. 3.25 mm), a pierced median nerve, and accessory heads of the flexor digitorum profundus (FDP) and flexor policis longus (FPL) muscles coexisting with a brachioradial artery (BRA) (diam.1.8mm) in the left upper limb of a 65 year-old male cadaver. The median nerve provided a ring for the passage of the PMA about the junction of the proximal and middle thirds of the forearm. Both accessory muscles were placed anterior to the ulnar artery, with the brachioradial artery coursing superficially in the brachium and antebrachium. The notable diameter of the PMA may be etiological in the causation of a carpal tunnel syndrome, while the hypoplastic BRA may pose some challenges in its selection as good conduit for catheterization and other surgical interventions like CABG in the upper limb. Additional clinical interest include the possible reduction in blood supply to the hand from the compressive effect of the 2 accessory muscles on the ulnar artery and possible inadvertent drug injection due to the superficial placement of the brachioradial artery close to veins.

Branches of the brachial plexus situated within the flexor compartment of the arm, the musculocutaneous, median and ulnar nerves maintain a predictive topography. The musculocutaneous nerve courses lateralward, the ulnar medial-ward, and the median between these. The present case features bilateral occurrence of ulnar and median transposition in a 74-year-old female cadaver. This transposition is related to dissimilar lengths of the lateral and medial roots of the median nerve. Both lateral roots of the median nerve were found to be unusually longer than usual. In addition, both medial roots coursed infero-medially instead of its usual superolateral coursing from their respective medial cords. These anomalies resulted in the median nerve being placed postero-inferior and medial to the ulnar nerve both lateral roots were observed crossing anterior to and impinging on their respective ulnar nerve. Clinical implications of the observed transposition include possible neurographic or MR ultrasonography misinterpretation of images. In addition such transposition may pose challenges to trauma surgeons engaged in nerve reconstruction following crush or mangled arm injuries. Anesthesiologists engaged in selective median or ulnar nerve blocks may witness increased procedural time and failures, as well as unexplained failure of analgesia in the skin areas normally supplied by their intended blocked nerve, a clinical situation that can be resolved by performing a neurostimulation.