[ rare case report of the Thyroidea Ima and the thymic arteries common trunk, arising from the brachiocephalic artery]

ABSTRACT

The Thyroidea Ima artery [The artery of Neubauer], was recognized and described by Neubauer in 1786. This artery which was described in the all anatomical textbooks may arise from the arch of aorta, brachiocephalic trunk or other arteries in the upper mediastina. It is considered as a compensatory artery when the other thyroidal vessels showed deficiencies. This artery showed greatly variation in size and gave some anastomotic branches to the thymic artery. The thymic artery arised from the anterior mediastinal branch of the internal thoracic artery but, may also arise from the brachiocephalic trunk, arch of aorta, common carotid or the main trunk of the internal thoracic artery. Its origin from the thyroidea ima is rare. This rare case was seen in a 65 years old male cadaver, the common trunk of the thyroida ima and the thymic arteries originated from the brachiocephalic artery. After a short course it divided into two branches an ascending [thyroida ima] and descending [thymic] branches. The thyroidea ima artery turned to left and upward to the lower border of the isthmus of thyroid gland. At this point it sent a branch to the lower part of the left lobe of the thyroid which penetrated it deeply and ended in the left inferior parathyroid gland. The main branch continued its course upward to the upper border of the thyroidal isthmus and divided into right and left branches. Each of these branches, after sending a great anastomotic branch to the superior thyroidal artery of their own side, terminated as several small branches in the upper part of the right and left lobes of the thyroid gland. The thymic artery continued its course downward for about three centimeters and ended as two branches in the right and left lobes of thymus. The thyroid gland of this cadaver was larger than the normal ones and the thymus was also clearly noticeable with right and left bobs. According to the embryonic origin and the developmental processes of the inferior parathyroid glands and the Thymus from the neighboring pharyngeal pouches, their blood supply from a common trunk will be acceptable especially when these two glands show some degree of enlargement as shown in this case. In the cases of thyroidectomies, when a surgeon is going to resect an enlarged thyroid gland, the presence of thyroidea ima artery and its branches to the lower part of lobes of thyroid gland would be a useful guidance to identify the inferior parathyroid glands an save them for the prevention of the next hypocalcemia