ENDOVASCULAR TREATMENT OF FUSIFORM ANEURYSMS WITH STENTS AND COILS - TECHNICAL FEASIBILITY IN A SWINE MODEL

PURPOSE: To assess the biomechanical feasibility of treating experimen tal Fusiform aneurysms endovascularly with a combination of stents and coils. METHODS: An experimental model was surgically constructed in t he necks of nine swine to simulate intracranial fusiform aneurysms pos sessing important ''perforators'' or side branches. Balloon-expandable metal stents were positioned across the aneurysms in eight swine. In five of these, additional treatment was intraaneurysmal placement of d etachable microcoils. Attempts were made to deposit these coils strate gically away from the origin of the side branch. RESULTS: Stent placem ent was successful in seven swine but failed in one swine because of s tent-aneurysm size mismatch. Two swine treated with only stents showed no significant alterations in blood filling of the aneurysm or side b ranch. Satisfactory coil placement (outside the stent, within the aneu rysm sac, and away from the orifice of the side branch) was achieved i n four of the five swine treated with stents and coils. Careful fluoro scopic monitoring and controlled coil delivery were necessary to avoid covering the side-branch origin. These aneurysms could not be packed densely after detachment of the first coil because of the resultant ra diographic overlap of multiple coil loops on the stent and its lumen i n all projections. In one swine there was inadvertent untoward reentry of the coil tip into the expanded stent lumen during its delivery. CO NCLUSION: Endovascular treatment of experimental fusiforms aneurysms u sing stents and coils is technically feasible. The stent maintains pat ency of the parent artery while allowing strategic coil placement in t he aneurysm sac away from the origin of side branches. This technique may prove useful in the future treatment of intracranial fusiform aneu rysms. However, potential sources of technical difficulties have been identified, and further long-term studies using an appropriate intracr anial stent will be necessary before human application.