Posterior Communicating Artery Aneurysm: Progressively Enlarging, Symptomatic, and Partially Thrombosed Fusiform True Posterior Communicating Artery Aneurysm, Treated by Coil Occlusion of the Parent Artery and Disconnection of the Posterior Communicating Artery by Parallel Flow Diversion in Two Treatment Sessions; Complete Aneurysm Occlusion, Aneurysm Shrinkage, and Good Clinical Recovery

Abstract

Back in 1998, a then 44-year-old male patient presented with a left hemispheric minor ischemic stroke of undefined cause and was diagnosed by DSA with a small, right-hand asymptomatic yet partially thrombosed true posterior communicating artery (TPcomA) aneurysm. The patient failed to regularly attend the assigned follow-up clinical and crosssectional imaging examinations. In 2016, 18 years after the first DSA examination, the patient presented with progressive left-hand hemiparesis and mild fluctuating central facial nerve palsy. Cranial non-contrast-enhanced computed tomography (NCCT) revealed the presence of a large lobulated and partially thrombosed right-hand TPcomA aneurysm. The thrombotic material in the aneurysmal sac was exerting a local mass effect on the thalamus and brainstem. Contralateral ischemic changes in the left-hand capsular region were also noted. Diagnostic angiography confirmed that the lobulated aneurysm originated from the right-hand "fetal" PcomA itself. In 1998, as well as in 2016, the patient clearly rejected all the treatment options offered. Another 2 years later, the patient presented with a worsening of his left-hand hemiparesis. A cranial MRI and the following DSA examination confirmed that the aneurysm had been progressively growing over the past two