Angiographic infundibular dilation: Is it worth exploring?

Infundibular dilations are generally considered normal anatomical variants devoid of pathogenic significance. However, some of them change in time and show certain characteristics similar to saccular aneurysms. Case Report: A 40-year-old male patient was hospitalized due to subarachnoid hemorrhage, resulting from the rupture of an aneurysm at the level of the anterior communicating artery. Additionally, an infundibular dilation of 6 mm in diameter was detected at the level of the right posterior communicating artery. The patient underwent an open surgery, using the pterional craniotomy approach to the right. The aneurysm of the anterior communicating artery was clipped with some difficulty because previous hemorrhage and hematoma were covering the aneurysmal neck. A mini clip was used to laterally decrease the infundibular dilation. Upon releasing the clip, we evidenced not an infundibulum, but a typical aneurysm, with the posterior communicating artery well attached to its wall, which was released and exposed at the time of clipping. Conclusion: Infundibular dilation is a potential source of bleeding, but it rarely ruptures and is little valued by radiologists and neurosurgeons. The care inherent in the discovery of an infundibular aneurysm, even if it is insidious, must be the same as that applied to classical types of aneurysm. Moreover, the therapeutic approach should be chosen when the infundibular aneurysm is equal to or greater than 4 mm in diameter.