Sueli Hoff Reckziegel

Colaterais do arco aórtico no Gambá (Didelphis albiventris)

In this research 28 specimens of Didelphis albiventris, 10 females and 18 males were used. After performing the injections with neoprene-latex stained with specif pigment, the animals were dissected. The right subclavian artery was originated from the braquiocephalic trunk in 11 cases (39.29%) and afterwards emerged the bicarotid trunk originating the right and left common carotid arteries. The braquiocephalic trunk divided into three branches, the right subclavian and the left and right common carotid arteries in 7 preparations (25%). The left common carotid artery was originated from the braquiocephalic trunk in 5 cases (17.86%), being followed by the right common carotid artery and the right subclavian artery. There was not a braquiocephalic trunk in 4 cases (14.28%), so it was first originated at the right subclavian artery and after the bicarotid trunk. The right subclavian artery and the right common carotid artery were originated from the braquiocephalic trunk in one case (3.57%), being the left common carotid artery originated directly from the aorta artery. The left subclavian artery originated directly from the aortic arch in all cases.

Origem ectópica da artéria subclávia direita e do tronco bicarotídeo no cão

The blood supply to the head, neck, thorax and thoracic limb come from the aorta artery through its two broad branches, the brachiocephalic trunk and the left subclavian artery, which arise from the arch of the aorta. The present report described the abnormal origins of the right subclavian and common carotid arteries observed in eigth dogs, during the last twenty years of dissection in anatomy classes. All these eight cases presented three large arteries that left the aortic arch. The first one to arise was a trunk for both common carotid arteries, then a left subclavian artery and finally a right subclavian artery. The bicarotid trunk was originated from the aortic arch at the left side of the trachea and course cranially towards the first rib, where it bifurcated into the right and left common carotid arteries. Following the left subclavian artery arose and after that the right subclavian artery, which arose directly from the aortic arch. This vessel ran towards the first rib and crossed the median plane at the dorsal aspect of the esophagus and the trachea. Both right and left subclavian arteries emitted the usual branches. Although the esophagus was indented by the anomalous vessel, the absence of a cranial dilatation around the sulcus and the good nutritional condition of the animals lead to a conclusion that the swallowing was not significantly affected.