Posterior Communicating Artery Aneurysm: Ruptured Aneurysm with Contained Pseudoaneurysm; Clinical Deterioration Due to a Massive Rehemorrhage After Insertion of Bilateral External Ventricular Drains

Abstract

This case concerns a 66-year-old female patient with spontaneous subarachnoid hemorrhage (SAH) (Hunt and Hess grade V) due to a ruptured aneurysm at the origin of the left posterior communicating artery (PcomA). A contained pseudoaneurysm had also formed adjacent to the rupture site. Once bilateral external ventricular drains (EVD) had been inserted, an elevated cerebrospinal fluid (CSF) pressure of up to 85 mmHg was revealed. The computer tomography (CT) performed after the CSF had been drained showed diffuse rebleeding completely filling the whole ventricular system, as well as cortical sulcal effacement. Catheter angiography confirmed a large pseudoaneurysm at the level of the left PcomA with ongoing extravasation of contrast medium into the ventricular system. Due to the patient’s unstable condition and poor prognosis, the aneurysm was not treated, and the patient died 3 h later. The possible association between relieving the CSF pressure and the destabilization of the contained aneurysm rupture resulting in massive rebleeding is the topic of this chapter.