Microsurgically induced aneurysm models in rats, part II:: Clipping, shrinking and micro-Doppler sonography

Introduction: To adapt to the changed approach in the treatment of aneurysms, the authors have developed three different experimental aneurysm models for teaching clipping, microvascular Doppler sonography and shrinking. Methods: 39 microaneurysms were created in 22 animals in three different locations at the carotid, femoral and iliac arteries and treated by neurosurgical clipping. Additionally, shrinking was accomplished in selected cases. Microvascular Doppler sonography with a 20-MHz microprobe was performed prior to and after clipping to assess the achieved result of the clipping manoeuvre. Multiple clip applications in different techniques were performed for optimisation of clip placement and additional training. Results: All created aneurysms could be clipped successfully. The mean duration for clipping and control of clipping results by the micro-Doppler was 8:51 4:41 minutes at all aneurysms. The aneurysm clip was repositioned in 16 of 39 (41 %) cases, on the basis of the Doppler findings in 14 aneurysms (36%). A relevant stenosis was detected in 10 (25.7%) and incomplete occlusion in 4 (10.2%) attempts. In one aneurysm vasospasm was detected at the distal part of the parent artery. Complete clipping was achieved in all cases. During the entire procedure three unexpected complications involving rupture and bleeding impeded the training. Conclusion: Surgically induced aneurysms in rats allow the possibility of multiple clipping, shrinking and micro-Doppler sonography for the simulation of aneurysm treatment.