-Case Reports-

An Unruptured Aneurysm Coexisting with an Infundibular Dilatation: A Case Report

Takao Kitamura, Yasuo Murai, Kazutaka Shirokane, Fumihiro Matano, Takayuki Kitamura and Akio Morita

Department of Neurological Surgery, Nippon Medical School, Tokyo, Japan

Background: Infundibular dilatation (ID) is a funnel-shaped enlargement of the origin of cerebral arteries. The coexistence of an aneurysm and ID is relatively rare. Patients with IDs are rarely followed up. However, some IDs have been reported to develop into aneurysms with subsequent rupture. Here we report on a case of an aneurysm that coexisted with ID of the posterior communicating artery.
Case Presentation: A 51-year-old woman underwent magnetic resonance imaging (MRI) to check for aneurysms and other problems. MRI revealed an unruptured aneurysm of the right internal carotid artery, for which the patient was admitted to our hospital. Three-dimensional computed tomographic angiography revealed an aneurysm, which protruded outward, and ID of the posterior communicating artery, which protruded inward. A right pterional craniotomy was performed with aneurysm clipping. The postoperative course was uneventful. In this report, we demonstrate operative views of the aneurysm and ID with the use of neuroendoscopy.
Conclusion: ID can develop into a true arterial aneurysm and potentially rupture. Therefore, we need to observe the patients with IDs carefully, particularly in young women.

J Nippon Med Sch 2016; 83: 268-271

Keywords
carotid artery, cerebral aneurysm, infundibular dilatation, neuroendoscopy

Correspondence to
Takao Kitamura, MD, Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan
taka-kitamu@nms.ac.jp

Received, June 15, 2016
Accepted, October 19, 2016