Abdominal Aorta

Variations in the abdominal aorta are not common. According to Quain, in 10 out of every 13 (about 80%) subjects examined, the bifurcation of the aorta occurred within 1.2 cm (~0.5 in) above or below the level of the highest point of the iliac crest, more frequently below the crest than above it. The most common place for its bifurcation, which is opposite the lower border of the body of the fourth lumbar vertebra, but it may divide opposite the disc between L4 and L5 or rarely opposite the body of the fifth lumbar vertebra. Bifurcation of the abdominal aorta occurs in about 75% of cases at this level. A higher division is less common (9%) than a lower division (11%). The artery has been found, however, dividing as high as the origin of the renal arteries, or even as high as the second lumbar vertebra.

The following rare variations of the abdominal aorta have been described:

1) The aorta may pass through the esophageal hiatus (opening) of the diaphragm.

2) It may lie on the right side of the vena cava, the vein passing over the upper part of the aorta to gain access to the caval hiatus.

3) The aorta may have a vena cava on each side, the left vein passing across the upper part of the artery to open into the right vein just below the caval opening.

In some cases the aorta gives rise to a pulmonary branch close to the origin of the celiac artery; the unusual vessel then passes through the esophageal opening and supplies a branch to the lower lobe of each lung.

The aorta may run to the right of the inferior vena cava.

Direct branches of the abdominal aorta sometimes include an accessory inferior phrenic, splenic, hepatic, accessory hepatic, supreme pancreatic, accessory superior mesenteric, inferior suprarenals, accessory gonadal, accessory and fifth lumbar, internal iliac, umbilical, and/or accessory median sacral.

The aorta may have a marked sinuous course throughout the abdomen.

Riferimenti dell’opera originale

Elenco riportato come compare nella fonte, senza normalizzazione dei formati bibliografici.

• Aleksandrowicz, R. (1974) Normal and pathologic dimensions of the abdominal aorta. Folia Morphol., Warsaw 33:309-315.
• Aleksandrowicz, R., Gosek, M. and M. Prorok. (1975) Dimensions of the lumen of the visceral branches of the abdominal aorta under normal and pathologic conditions. Folia Morphol., Warsaw 34:77-84.
• Annan, J.L. (1910) Case of an abnormal sinuous aorta. J. Anat. Physol. 44:241-243.
• Bergman, R.A., Thompson, S.A., Afifi, A.K. and F.A. Saadeh. (1988) Compendium of Human Anatomic Variation: Catalog, Atlas, and World Literature. Urban & Schwarzenberg, Baltimore.
• Broman, I. (1908) über die Entwicklung und "Wanderung" der Zweige der Aorta abdominalis beim Menschen. Anat. Hefte 36:407-549.
• Cauldwell, E.W. and B.J. Anson. (1943) The visceral branches of the abdominal aorta. Topographical relationships. Am. J. Anat. 73:27-57.
• Cole, F.H., Alley, F.H. and R.S. Jones. (1951) Aberrant systemic arteries to the lower lung. Surg., Gynecol. Obstet. 93:589-596.
• Kostinovitch, L.I. (1937) Acase of simultaneous occurrence of a number of variations of the visceral branches of the abdominal aorta. Anat. Rec. 67:399-403.
• Poynter, C.W.M. (1922) Congenital anomalies of the arteries and veins of the human body with bibliography. The University Studies of the University of Nebraska 22:1-106.
• Turner, W. (1863) On the existence of a system of anastomosing arteries between and connecting the visceral and parietal branches of the abdominal aorta. Br. Foreign Med. Rev. 32:222-227.
• Tyrie, C.C.B. (1894) Axial rotation of the abdominal aorta, with associated abnormalities of the branches. J. Anat. Physiol. 28:281-287.
• Variations in the Branches of the Abdominal Aorta The following variations have been recorded in the branches of the abdominal aorta. Inferior Phrenic Artery Lumbar Arteries