Aneurysmal and Perianeurysmal Changes After Endovascular Treatment: from Inflammation to Microbleed. A Case Report.

The advent of flow diverter (FD) stents has deeply changed the endovascular treatment of cerebral aneurysms. Endosac- cular devices have been replaced by endoluminal stents and the management of FD-treated patients differs markedly from that of patients treated with metal coils. Whichever technique or devices are used, a thrombus forms within the aneurysmal sac after treatment. The ensuing events are well known: clot formation and inflammation develop in a physiological healing process that takes from months to years These new devices have also given rise to several unpre- dictable complications, including still unexplained fatal case of spontaneous rupture of treated aneurysms The mechanism of post-flow-diversion haemorrhage remains difficult to clearly understand: aneurysm thrombosis, fol lowed by mural inflammation, leading to autolysis and rupture has been described.Nevertheless thrombosis followed by organization and neo-intimal closure of the neck is required for successful occlusion of treated aneurysms, thus there must be further elements to consider for thrombosis leading to rupture rather than occlusion. This report describes the favourable outcome of a focal wall rupture affecting a large carotid-ophthalmic artery aneurysm treated with FD and coils deployment. It displays the potential interaction between thrombosis, inflammation and residual flow in the aneurysm.