Embolotherapy of aneurysms under temporary balloon occlusion of the neck -: In vitro study of a newly designed eccentric balloon catheter

RATIONALE AND OBJECTIVES. TO test embolotherapy of aneurysms in an in vitro model using standard and specially designed eccentric occlusion balloon catheters for simultaneous delivery of the embolization agent and occlusion of the neck of the aneurysm. METHODS. Two different in vitro set-ups were used: a bifurcational aneurysm and an aneurysm with a straight parent vessel segment, both made from elastic silicone and glass. Each model was exposed to a pulsating perfusion. The effluent was collected and filtered. For the bifurcational aneurysms, commercially available occlusion balloon catheters with a working channel exiting at the tip were used. For the aneurysms with straight parent vessel, the catheters were modified so that the balloon opened eccentrically. The working channel of the catheter led to a side hole, which was located where the balloon membrane was fixed to the catheter shaft. The aneurysms were filled with coils, ethibloc, or hydrogel, and with coils combined with ethibloc or hydrogel, while the expanded balloon Occluded the neck. RESULTS. Embolization of aneurysms under balloon occlusion of the neck was technically feasible with the catheter devices. Dense packing with coils was possible in all cases without coil dislocation, but unfilled interspaces remained between the coil wires. Best filling was achieved with ethibloc or hydrogel alone or in combination with coils. During the filling procedure, there was no distal embolization of the liquid agents. However, after balloon deflation, considerable amounts of hydrogel or ethibloc were washed out from the aneurysm. CONCLUSIONS. The results suggest that balloon occlusion of the neck allows compact filling and minimizes the risk of dislocation in coil embolotherapy of aneurysms. In nonbifurcational aneurysms, the eccentric balloon catheter seems to be suitable for this treatment concept. Although liquid agents may be safely delivered into the aneurysm under balloon protection, their considerable washout rate after balloon removal requires further refinements of the technique before clinical application is advisable.