This section is from the book "Anatomy Of The Arteries Of The Human Body", by John Hatch Power. Also available from Amazon: Anatomy of the Arteries of the Human Body, with the Descriptive Anatomy of the Heart.
The aorta sometimes bifurcates at the third lumbar vertebra, or as high as the second,* or immediately after giving off the renal arteries. Dr. Green met with the following varieties in this vessel:In a child born with imperforate anus, the aorta divided in the lumbar region into two branches; one of which gave off the inferior mesenteric, then crossed to the back of the bladder, and ascended along the median line to bifurcate at the umbilicus: the other branch, situated behind the former, was reflected towards the right sacro-iliac symphysis: having supplied the left side of the pelvis and left lower extremity, the continuation of it became the right femoral: the arch of the aorta gave off three branches: first, a trunk common to both carotids; secondly, a left subclavian; thirdly, a right subclavian, which crossed behind the oesophagus. The left kidney and renal artery were wanting. A case of obliteration of the aorta immediately below its arch is related by Dessault.* It appeared, from examination of the body, that during life the blood which was expelled from the heart must have been transmitted into the trunk of the aorta below the constriction, by passing through the subclavian, axillary, and cervical arteries. From these latter it passed into the vessels of the thoracic and abdominal viscera, and those of the lower extremities. Dr. Graham, of Glasgow, published another example of complete obstruction of the aorta just below the ductus arteriosus. There are several other cases of this kind recorded.
* " Anatom. Societ. a. g. Mars," 1835.
Journal des Progres, 1828, vol. viii. p. 191.
The following instances, having occurred in the abdominal region, are more to our present purpose. M. A. Severin speaks of an obstruction of the aorta beneath the emulgent arteries. Monro describes an obliteration of this vessel above the common iliac arteries. Crampton also saw it obliterated in the abdominal region; and Larrey and Key have described similar cases. Dr. Goodison, of Wicklow, examined at Paris the body of a woman in whom the aorta was obliterated immediately beneath the inferior mesenteric artery. The left common iliac artery was impervious in its entire length, and the right common iliac in one-half: the limbs did not appear at all emaciated. The history of this case could not be ascertained. The late Sir P. Crampton examined the preparation, and was of opinion that the obliteration was the effect of a process by which an aneurism had been spontaneously cured. In all the above cases, the circulation had been established below the obstruction; and in none, except the cases of Larrey and Key, did there appear to have been any weakness in the limbs.
* Dessault's Journal, vol. ii.
Med. Chir. Trans., vol. v. p. 287.
Dub. Hosp. Rep., vol. ii. p. 193.
The Cceliac axis may be deficient; or it may give off only the hepatic and splenic arteries; or the hepatic, splenic, and capsular; or it may, in addition to its usual branches, give off the phrenic and gastro-epiploica dextra, or the superior mesenteric.
This artery has been found arising from the aorta, in common with one of the phrenics; and it frequently gives a branch to the liver.
This has been said to be wanting. There may be two hepatic arteries; one from the cceliac axis, and the other from the aorta, or from the gastric artery. The hepatic artery may come directly from the aorta or from the superior mesenteric artery. Accessary branches from the renal, or from other sources, may be expended in the liver.