Bifurcation Of Axillary Artery In Its 3rd Part - A Case Report

Transcription

1 166 J Anat. Soc. India 50(2) (2001) Bifurcation Of Axillary Artery In Its 3rd Part - A Case Report *Patnaik, V.V.G.; **Kalsey, G.; **Singla, Rajan K. Department of Anatomy, Government Medical College, *Patiala, **Amritsar, INDIA. Abstract. In the present paper,a case of bifurcation of axillary artery in its 3rd part into radial artery and brachio ulnar artery is being reported. Former branch coursed superficial to median nerve in arm and continued in the forearm as such while later one after giving branches of brachial artery in the arm continued as ulnar artery in forearm and hence named so. Further its ontogeny & elinical implications are discussed in detail. Key words : Axillary artery, Radial artery, ulnar artery. Superficial brachial artery Case report : During the dissections done in the Anatomy Department of Govt. Medical College, Amritsar under the project of Arterial Pattern of Superior Extremity of Human Adult- A Morphological Study, a case of bifurcation of axillary artery in its 3rd part was encountered. The limb belonged to the left side of an approximately 40 years old male cadaver. The axillary artery in its 3rd part at a distance of 7.5 cm from outer border of first rib and 3.0 cm proximal to lower border of teres major (distance between outer border of first rib and lower border of teres major i.e. total extent of axillary artery being 10.5 cm) divided into 2 branches. One of these branches coursed superficial to median nerve from medial to lateral side in the middle one third of the arm and continued in the forearm as radial artery. The other one gave off anterior and posterior circumflex humeral, subscapular and arteria profunda brachii branches, coursed deep to the median nerve from lateral to medial side and continued in the forearm as ulnar artery. (See Photograph 1 & 2). Further course, branches, and termination of radial and ulner arteries in forearm and hand were normal. Discussion : Axillary artery dividing in its 3rd part has been differently named by earlier workers. One of the divisions which passes superficial to median nerve and replaces the main trunk is named superficial brachial artery by Adachi (1928). Treves and Rogers (1947) opined that there are 2 brachial arteries instead of one continuing as radial and ulnar arteries. Keen (1961) christened this variation as high origin of radial artery. Icten and Tuncar (1996) differentiated high origin of radial artery and superficial brachial artery as separate entities saying that the former arises from axillary or brachial artery and continues in the forearm as does a normal radial artery. On the other hand though the persistent superficial brachial artery has same origin as a high origin radial artery, but on reaching the forearm, it usually divides into radial and ulnar arteries while the brachial artery merely supplies the interosseous. Former condition according to them is 13 times more common as compared to the later. We feel that it should be called Bifurcation of axillary artery into radial and brachio ulnar trunks with former continuing in forearm as such while later giving branches of brachial artery in arm and then continuing in forearm as ulnar artery and hence named brachio ulnar. Ontogeny : Arey (1957) is of the view that the anomalous blood vessels may be due to (i) the choice of unusual paths in the primitive vascular plexuses, (ii) the persistence of vessels normally obliterated, (iii) the disappearance of vessels normally retained (iv) incomplete development and (v) fusions and absorption of the parts usually distinct. Ontogenic basis of the present case can be easily made out if we look at Singer Staging of development of brachial artery according to which it develops in the following 5 stages (See Text Fig. I) :

2 Patnaik, V.V.G. et al (I) (II) (III) (IV) (V) Text Fig. 1 Stages of Development of arteries of upper limb sc Subclavian artery ma Median artery aia Anterior interosseous sba Superficial brachial artery artery ua Ulnar artery spa Superficial palmar arch ra radial artery Stage I: Originally the subclavian artery extends to the wrist, where it terminates by dividing into terminal branches for the fingers. The distal portion of the artery becomes the interosseous artery of the adult. Stage II : The median artery arises from the interosseous artery and becomes larger while interosseous artery subsequently undergoes retrogression. During this process the median artery fuses with the lower portion of interosseous artery and ultimately forms the main channel for the digital branches becoming the principle artery of the forearm. Stage III : In embryos of 18 mm, the ulnar artery arises from brachial artery and unites distally with the median artery to form superficial palmar arch. Digital branches arise from this arch. Stage IV: In embryo of 21 mm length, the superficial brachial artery develops in the axillary region and traverses the medial surface of the arm and runs diagonally from the ulnar to the radial side of the forearm to the posterior surface of the wrist. There it divides over the carpus into branches for the dorsum of the thumb and index finger. 167 Stage V: Finally three changes occur. When the embryo reaches the length of 23 mm the median artery undergoes retrogression becoming a small slender structure, now known as arteria comes nervi mediani. The superficial brachial artery gives off a distal branch which anastomoses with the superficial palmar arch already present. At the elbow an anastomotic branch between brachial artery and superficial brachial artery becomes enlarged sufficiently to form with the distal portion of the latter, the radial artery, as a major artery of the forearm; the proximal portion of the superficial brachial artery atrophies correspondingly. (Singer, 1933) In the present case, (See Text fig. II) the third part of axillary artery (e) gave off superficial brachial artery (a) which appeared there in Singer s stage IV and continued downwards as radial artery. Ulnar artery (c) had appeared from axial artery at usual level. The communicating branch between superfiial brachial artery and axial artery at level of elbow failed to develop and so superficial brachial artery did not dissappear but continued as radial artery. On the other hand part of axial artery (d) (distal to origin of ulnar artery) shrunk in size and ultimately it appeared as if axial artery continued as ulnar artery (c) and common interosseous (d) arose as its branch. a - Superficial brachial artery (Radial division of axillary artery) b - Primitive axial artery (brachial part of brachioulnar trunk) c - Trunk of origin of ulnar artery (ulnar part of brachio - ulnar trunk) d - Part of axial artery distal to origin of ulnar artery e - Third part of axillary artery f - Median nerve Text Fig. 2 Ontogenic explanation of Bifurcation of axillary artery

3 168 Baeza et al (1995) look at the normal development of upper limb arteries in a slightly different way (See Text Fig. III). According to them : 1. The superficial brachial artery is a consistent embryonic vessel that plays an important role in the normal arterial morphogenesis of the upper limb. 2. The superficial brachial artery has two terminal branches (Muller; 1903; Vancov, 1961); a medial one which is superficial antebrachial artery and lateral one which continues in the forearm as a part of the definitive radial artery. Text Fig. 3 Modifications by Baeza et al (1995) in development of human brachio-antebrachial system a - Primitive axial artery b - Superficial brachial artery c - Lateral branch of superficial brachial artery d - Medial branch of superficial brachial artery (superficial ante-brachial artery) e - Trunk of deep origin of radial artery f - Radial artery g - Ulnar branch of superficial ante-brachial artery h - Median branch of superficial ante-brachial artery i - Trunk of deep origin of ulnar artery j - Trunk of deep origin of median artery k - Ulnar artery l - Median artery m - Common interosseous artery Bifurcation of Axillary Artetry 3. The superficial antebrachial artery (medial branch of superficial brachial) divides into 2 terminal branches - median and ulnar (Muller, 1903; Lanz and Wachsmuth, 1959; Vancov, 1961). Each of these branches anastomose with a corresponding branch of primitive axial artery which are trunks in origin of the median and ulnar artery respectively. Gradually trunks of deep origin attain a haemodynamic predominance and superficial antebrachial artery together with the pre-anastomotic segment of its terminal branch regresses. Therefore, 2 segments can be distinguished in both the median and ulnar arteries; a proximal or deep one which corresponds to the trunk of origin in the primitive axial artery and another distal or superficial which represents postanastomotic segment of the terminal branch of superficial antebrachial artery. 4. The radial artery usually develops similarl to median and ulnar arteries. Thus the lateral terminal branch of superficial brachial artery anastomoses with a trunk of the deep origin of the radial artery from the primitive axial artery. Deep haemodynamic predominance determines regression of those superficial arterial segments located proximal to the anastomosis, while the distal segments persist as a part of the radial artery. This explanation is in agreement with that given by Senior (1926) and Singer (1933). However, they defined the superficial branch of the anastomosis as the proper superficial brachial artery and not as its lateral terminal branch. This difference may be justified by the fact that once the anastomosis between the trunk for the deep origin of the radial artery and lateral branch of superficial brachial artery is made, the definitive patterns of the median and ulnar arteries have already been established. Baeza et al (1995) s explanation also stands a good stead in the present case. The lateral branch of superficial brachial artery continued as radial artery and trunk of deep origin of radial artery failed to develop, or if it developed, it failed to attain haemodynamic predominance and the lateral branch of superficial brachial artery continued as

4 Patnaik, V.V.G. et al radial. In case of ulnar artery that developed normally with ulnar branch of superficial antebrachial artery (medial branch of superficial brachial artery) failing to attain haemodynamic predominance and trunk of deep origin from primitive axis artery attaining the same so that ultimately whole of the ulnar artery seems to be a continuation of brachial artery with interosseous coming as its branch Vancov, V. (1961) : Une Variete extremement complexe des arteres du membre superieur chez in foetus humain Anatomical Anzeles 109: pp This Article Can be Downloaded / Printed Free from Clinical implications : Compta (1991) highlighted the diagnostic, interventional and surgical significance of such a variation. Diagnostically, it may disturb the evaluation of angiographic images. Interventionally, accidental puncture of superficially placed arteries may occur while attempting venipuncture. Surgically, it is vulnerable in both orthopaedic and plastic surgery operations. References : 1. Adachi, B: Das Arteriensystem des japaner, Kyoto, Vol. 1; pp. 8, 205, 208, 210 (1928). 2. Arey, L.B.: Developmental Anatomy In : Development of the Arteries, 6th Edn, W.B. Saunders co; Philadelphia, pp (1957). 3. Baeza, R.A.; Nebot, J; Ferreira, B; Reina, F; Perez, J; Saundo, J.R. and Roig, M (1995): An anatomical study and ontogenic explanation of 23 cases with variations in main pattern of brachio antebrachial arteries. Journal of Anatomy 187(2): pp Campta, X.G. (1991): Origin of radial artery from the axillary artery and associated hand vascular anomalies. Journal of Hand Surgery 16(A): pp Icten, N; Tuncar, I (1996): Variant high origin of radial artery: A bilateral case. Surgery, Radiology, Anatomy, 18(1): pp Keena, J.A. (1961): A study of arterial variations in the limbs with special references to symmetery of vascular patterns. American Journal of Anatomy, 108: pp Lanz, T; Wachsmuth: Practiche Anatomie Vol. 1: Part 3, Arm Springer, Berlin pp : (1959). 8. Muller (1903): Die Arm-Arterian des Mechshen Anat Hefte; 22: p Senior, H.D. (1926): A note on development of radial artery. Anatomical Record 32: p Singer, E (1933): Embryological patterns persisting in the arteries of the arm. Anatomical Record, 55: pp Treves, F.B.; Rogers, L: Surgical applied anatomy In: The upper extremity. 11th Edn. Cassell & Co. Ltd. London, pp (1947).

5 Opp. 166 Bifurcation of Axillary Artery Photograph 1 Bifurcation of axillary artery (ax) into radial (r) & brachio ulnar (bu). r passed superficial to median nerve (mn) & while bu coursed deep to mn & continued as ulnar artery (u). Photograph 2 Bifurcation of axillary artery (ax) in its 3rd part. pm - Pectoralis minor; a - anterior et p - posterior circumflex humeral arteries. pb - profunda brachii.