In 1942, Leriche described the first "dolichomégaartères" (or "arteriomegaly" according to the definition subsequently proposed by Anglo-Saxon researchers). We detected 199 cases of arteriomegaly (16.29% of cases examined) during a review of 1,221 translumbar arteriographies of the lower limbs performed from 1980 to 1985 in the vascular radiology department of our hospital. The percentage of associated aneurysms was 33.16%. The possible dysplastic pathogenesis of the affection and the differential diagnosis with atherosclerosis and other vascular affections found in connective tissue diseases is noted. Histopathology showed dystrophic lesions of the media and especially of the elastic fibers as well as occasional associated venous lesions and a familial basis. The peripheral symptomatology was acute, pseudoembolic and severe as revealed by ischemia and cyanosis. There was no collateral circulation. Medical treatment consisted especially in anti-coagulant and hypervolemic hemorrheologic therapy during ischemia. Ultrasonography enabled us to monitor the regular, systematic course of arteriomegaly, to make the diagnosis initially, to measure the exact size of the arteries, to observe the morphology of the wall and, moreover, to determine the presence or not of megaveins capable of reinforcing the dysplastic genesis of arteriomegaly.