Thrombosed Giant "True" Posterior Communicating Artery Aneurysm Treated by Trapping and Thrombectomy.

Giant "true" posterior communicating artery (PCOM) aneurysms are rare and the best surgical treatment for them is unclear. We present a case of 85-year-old woman with this type of lesion, 35 mm in diameter, successfully treated by trapping and thrombectomy via pterional approach without complications. There were no perforating arteries originating from the aneurysmal wall. The patient had an uneventful postoperative course. The key for successful treatment for such lesions is preservation of perforators, as trapping may result in ischemic complications. However, our case indicates that trapping and thrombectomy might have relatively low risks for development of such complications, supposing that the thrombosis within the giant "true" PCOM aneurysm induced spontaneous obliteration of perforators, arising from the aneurysmal dome, and that collateral flow from the posterior cerebral artery already compensated the corresponding territories.