Search Results

You are looking at 1 - 3 of 3 items for

  • Author or Editor: Alan S. Boulos x
  • User-accessible content x
Clear All Modify Search
Full access

Eric M. Deshaies, Sandeep Bagla, Celso Agner and Alan S. Boulos


Coil embolization of aneurysms has been shown to be as safe and effective as surgical clip ligation, but has a higher recurrence rate. Advances in coil technology aim to reduce aneurysm recurrence by coating the devices with biological substances. An example of this is MicroVention's HydroCoil, which is a platinum coil coated with hydro-gel that improves filling volumes by swelling when it contacts blood. The goal of this study was to determine whether this new coil type significantly reduced or prevented recurrences of aneurysms.


The authors used three-dimensional computerized tomography angiography to determine aneurysm volumes accurately in 12 patients prior to coil embolization. The percentage filling volume was subsequently calculated for each aneurysm after treatment with HydroCoils and the immediate and 6-month follow-up angiographically confirmed occlusions were evaluated. The data demonstrated that both anterior and posterior intracranial aneurysms with diameters of 3 to 25 mm and volumes of 0.03 to 4.8 ml had filling volumes of 0.02 to 1.36 ml, resulting in filling volumes from 23% in a giant ophthalmic artery aneurysm to 80% in a small anterior communicating artery aneurysm. All of the aneurysms except for the giant one demonstrated stable occlusion on angiographic studies obtained at the 6-month follow-up review.


HydroCoil embolization of intracranial aneurysms is safe and effective for small, large, and very large aneurysms. The percentage filling volume is greater than that reported for bare platinum coils in every case except the giant aneurysm. Nevertheless, angiographically confirmed occlusion is not directly related to percentage filling volume, but rather to the ability to occlude the aneurysm neck.

Full access

Akeel Merchant, Doniel Drazin, John Dalfino, Junichi Yamamoto and Alan S. Boulos

The authors report a case of restenosis in the bilateral internal carotid arteries (ICAs) following angioplasty for cerebral vasospasm. This 53-year-old woman suffering subarachnoid hemorrhage due to a ruptured posterior communicating artery aneurysm had severe vasospasm and underwent angioplasty of the left and right ICAs and middle cerebral arteries. Two months later, a follow-up CT angiogram revealed bilateral ICA stenoses.

Transluminal angioplasty leads to long-term connective tissue damage in the medial and adventitial layers from the disruption of the arrangement of collagen fibers due to stretching and tearing, resulting in loss of transmission of contractile forces. Furthermore, following endothelial cell denudation and stretching and rupture of internal elastic lamina from angioplasty, reendothelialization of the intimal layer composed of smooth muscle cells may also explain the contractile properties of restenosis. Other factors such as macrophage-induced inflammation and reactive oxygen species accumulation may also contribute to restenosis. This is the second reported case of restenosis following angioplasty to treat vasospasm, although restenosis is a known complication of angioplasty for treatment of atherosclerosis. In addition, this is the first case of restenosis in the bilateral ICAs following angioplasty for vasospasm. This report presents an illustrative case study and reviews the pathophysiology of angioplasty and restenosis.

Full access

Ricardo A. Hanel, Alan S. Boulos, Eric G. Sauvageau, Elad I. Levy, Lee R. Guterman and L. Nelson Hopkins

Vertebrobasilar nonsaccular aneurysms represent a small subset of intracranial aneurysms and usually are among the most challenging to be treated. The aim of this article was to review the literature and summarize the experience in the treatment of these lesions with endovascular approaches. The method of stent implantation as it is performed at the authors' institution, including options available for vertebral artery access, is described. Practitioners involved in the treatment of these lesions should be aware of the potential application of intravascular stent placement as well as the associated postprocedure risks and potential complications.