Distribution pattern of sudanophilic plaques in the descending thoracic and proximal abdominal human aorta.

The localization of sudanophilic plaques around the intercostal ostia and the origin of the superior mesenteric and coeliac artery was examined in 38 human aortae. The perimeter of the opened aorta and the outline of each sudanophilic plaque were digitized and computerized. By means of a special program the results were displayed as progressive contour lines connecting points with an equal frequency of plaques. This study shows that the sudanophilic plaques have a distinct spatial distribution both in the thoracic and abdominal aorta. Around the intercostal ostia peak frequency of plaques is found just proximal to the lower lip of the ostia. In the bifurcation of both the superior mesenteric and coeliac artery the plaques are present on the outer walls while the inner walls and the apex itself are free of plaques.