No abstract

No abstract

The proximal part of the posterior communicating artery is often funnelshaped at its origin from the carotid siphon and may vary considerably in size and outline (ref. 4, Fig. I). In some cases in which the posterior communicating artery has not been filled, a broad-based varying bulge in the wall of the carotid siphon may be evident at the site where the posterior communicating artery arises (ref. 4, Fig. 2). A survey ofa normal material of 1020 angiographies (angiographies without evidence of other vascular changes) revealed bulging of the vessel wall at the typical site in 67 cases (SALTZMAN). Approximately the same incidence was established in a material comprising 223 cases of intracranial expansive processes and 118 cases of arterial aneurysm in the carotid region. The figures correspond to ten per cent of the carotid angiographies in which the posterior cerebral artery was not demonstrated. The appearance of the bulge corresponded in many cases with the funnel-shaped proximal part of the posterior com-

Angiographic investigations ( S a l f z m a n ) have demonstrated that the proximal portion of the posterior communicating artery is not infrequently funnel-shaped and appreciably wider than other parts of the vessel. A more or less funnel-shaped bulging of the wall of the carotid artery a t the origin of the posterior communicating artery may sometimes be observed at carotid angiography in patients in whom the latter vessel does not fill with contrast medium. This type of lesion is seen in 10 per cent of all those cases in which the posterior communicating artery is not visible. Rapid serial angiography, as well as repeated conventional angiographic examinations, disclose that these bulges correspond to the proximal, infundibularly enlarged portion of the posterior communicating artery.

No abstract