Splenic artery aneurysms; report of 17 cases showing calcification on plain roentgenograms.

Abstract

Since the first description of splenic artery aneurysm by Beaussier in 1770, only 213 cases have been reported in the literature, so far as we can determine. Winkler, in 1903, was the first to identify splenic artery aneurysms in a living person, and Hoegler, in 1920, made the first preoperative diagnosis. The first diagnosis to be based on roentgen examination alone was made by Lindboe in 1932. In 1950, Evans obtained the first translumbar aortogram demonstrating a splenic artery aneurysm. Owens and Coffey in a review of the literature in 1953 found reports of 198 cases of splenic artery aneurysm, to which they added 6 further examples. Since then, 9 additional instances have been recorded. Of the total of 213 cases in the literature, only 19 were diagnosed roentgenographically or clinically prior to operation. In 11 of the 19, the condition was recognized by the presence of a calcified ring shadow on abdominal roentgenograms, and in 3 of these confirmation was obtained by lumbar aortography. In 1 instance, the diagnosis was made by aortography alone. In the remaining cases, the presence of a pulsating or non-pulsating mass or bruit in the left upper quadrant suggested the diagnosis. In a total of 96,741 autopsy reports collected by Owens and Coffey from various articles, only 37 splenic artery aneurysms were mentioned, an incidence of 0.038 per cent. While aneurysms in general are more common in the male than in the female (a ratio of 5 to 1), aneurysms of the splenic artery occur more frequently in the female (ratio of 2 to 1). Among 186 cases, Owens and Coffey found the average age to be forty-eight years, with a range from fourteen to eightyeight years. Forty-six per cent of the females were in the childbearing age, and of these 53 per cent were pregnant at the time the aneurysm was identified. While the exact cause of aneurysm of the splenic artery is not known, several factors appear to be important. Arteriosclerotic changes in the splenic artery have been found more often than any other pathologic condition. Frequently, the arteriosclerosis involves the splenic artery only, and no other vessel. The artery is tortuous, and the arteriosclerotic changes are most prominent on the convexities of the bends. It is at these sites that aneurysms usually develop. Endocarditis and embolization of the splenic artery may in some instances be responsible for splenic artery aneurysms. Congenital defects in the internal elastic membrane of the intima or congenital fibrotic areas in the media of the artery have also been suggested as possible causes. Unlike aortic aneurysms, aneurysm of the splenic artery is seldom attributable to syphilis. In a few cases it has been ascribed to trauma and infection. In 20 per cent of Owens and Coffey's collected series, portal hypertension was found.