A Collagen-Based Coil for Embolization of Saccular Aneurysms in a New Zealand White Rabbit Model

Subject 8, aneurysm packed with collagen coil (10-week sample).

A, DSA image, showing aneurysm cavity.

B, Radiograph, showing collagen coils after implantation. Loose packing was present in the aneurysm cavity (long arrow) with a loop of coil present in the parent artery distal to the aneurysm cavity (short arrow).

C, DSA image, immediately after coil implantation, demonstrating large amount of residual flow in the body of the aneurysm cavity. No compromise of flow existed in the parent artery distal to the aneurysm cavity.

D, DSA image, 10 weeks after implantation, showing interval progressive aneurysm occlusion, with no residual flow in the aneurysm cavity and a triangular neck remnant (long arrow). Flow remained unimpeded in the region of the coils in the distal parent artery (short arrow).

Subject 3, aneurysm packed with collagen coil (2-week sample).

A, Histologic specimen showing the neck of the aneurysm covered by a thick layer of tissue consisting of nucleated cells (arrows). (Hematoxylin and eosin stain, original magnification ×40.)

B, Histologic speciment showing dense blue staining indicates collagen deposition within the aneurysm cavity. Vascular channels are also present. (Trichrome stain, original magnification ×100.).

Subject 7, aneurysms packed with collagen-based coil (10-week sample). Histologic specimen showing the aneurysm cavity is filled with dense matrix and spindle cells. (Hematoxylin and eosin stain, original magnification ×20.).

Subject 5, aneurysms packed with platinum coil (2-week sample). Histologic specimen showing the aneurysm cavity is filled with unorganized thrombus. The thrombus in the dome is laminated, suggesting ongoing turnover of unorganized thrombus. (Hematoxylin and eosin stain, original magnification ×20.).