Acute Human Histopathology of an Intracranial Aneurysm Treated Using Guglielmi Detachable Coils: Case Report and Review of the Literature

Abstract

This case represents one of the first examples in humans of the formation of a membrane over the aneurysm orifice after GDC therapy. The formation of this membrane, shown to be composed of fibrin, was found at 36 hours after coiling, which is the earliest time frame at which membrane formation has been noted in either humans or animal models. This fibrin membrane may function both as a scaffold for subsequent endothelialization across the aneurysm neck as well as to isolate the aneurysm from the parent circulation, permitting thrombus within the aneurysm sac to mature to an endovascular scar. The factors contributing to the formation of this membrane and its clinical implications are discussed.

Endovascular Treatment of Asymptomatic Cerebral Aneurysms: Anatomic and Technical Factors Related to Ischemic Events and Coil Stabilization

“…Natural history of cerebral aneurysms treated with GDCs Post-treatment progressive thrombosis, and regrowth and recanalization of neck remnants are strongly dependent on arterial inflow. 12,39,40) Direct arterial inflow is reduced in aneurysms with a small neck. However, the geometric mismatch between the convex margin of the GDC surface and the neck allows continuous arterial inflow in aneurysms with a wide neck and large aneurysms that carry a high risk of parent artery compromise.…”

“…There are few histopathological studies on human GDC-treated aneurysms. 27,40) In an experimental model, only 23-26% of the aneurysm sac volume was replaced by coils, 41) and radiologic and histopathologic findings on obliteration were variable. 34,39) Complete aneurysm occlusion with GDCs is difficult to unequivocally determine despite multiple angiographic projections and completeness of initial packing.…”

Usefulness of the Behavior of Fibroblast Attachment to Coils in Thermoreversible Gelation Polymer for Aneurysmal Coil Treatment

“…In vivo however, endothelial overgrowth from the aneurysm orifice margins progressively covered the already fibrotically organised parts of the cloth inspite the presence of fresh thrombus in some parts of the occluded aneurysm [12]. In endothelialization a fibrin membrane across the orifice of aneurysm appeared 36 hours after embolization [29] and afterward endothelial cells seemed to elongate on that membrane [30]. This endothelialization is the final stage of aneurysm exclusion from the parent vessel circulation [11].…”

Cerebral Aneurysm Regrowth and Coil Unraveling After Incomplete Guglielmi Detachable Coil Embolization: Serial Angiographical and Histological Findings-Case Report-

“…18) Only a few cases of histological examination of human intracranial aneurysm have been reported. 8,12,13,17) Endothelialization of the GDC-treated aneurysm in humans is controversial. The final cure caused by GDC embolization is complete elimination of the aneurysm from blood flow by a newly formed endothelial membrane over the aneurysm orifice.…”