Lumbar arteries are in series with the posterior intercostal. arteries. The aim of this study has been to investigate the morphometric data on the abdominal aorta of the human fetus and define different types of origin variations of the Lumbar artery. Initially, the latex solution colored with red ink was injected into the thoracic aorta. The abdominal. aorta and its branches were dissected and examined bilaterally in 120 fetuses (ranging between 16 and 32 post-menstrual. weeks) and the anatomic variations recorded. Fourteen fetuses with variations were studied and photographed. The origins and morphologic variations of the lumbar arteries were defined and classified. The morphological. relationship of the Lumbar arteries to the abdominal. aorta and the Length and width (diameter) of the vessels were investigated by performing measurements using a digital calliper (mm). The frequency and the types of the different variations determined in the present study have been Listed. Abdominal aortic branches and lumbar artery aneurysms are rare lesions with potentially life-threatening consequences and they are difficult to access anatomically and formidable to manage operatively. During the performance of conventional or open surgical. replacement of an abdominal aortic aneurysm with prosthetic grafts, the surgeon needs precise knowledge of the anatomy of the abdominal. aortic branches and immediate retroperitoneal. structures. The variations on the lumbar arteries may have clinical importance. When this region is under diagnostic and/or surgical investigation using computed tomography scan or diagnostic angiography, the possibility of these variations should be take into consideration to avoid complications. (c) 2005 Elsevier GmbH. All rights reserved.