Microsurgically produced bifurcation aneurysms in a rabbit model for endovascular coil embolization

Area of Science:

• Neurosurgery
• Vascular Surgery
• Medical Imaging

Background:

• Bifurcation aneurysms are common and challenging cerebrovascular lesions.
• Endovascular coil embolization is a primary treatment modality for aneurysms.
• Accurate assessment of treatment efficacy is crucial for patient outcomes.

Purpose of the Study:

• To develop a reliable animal model of bifurcation aneurysms in rabbits.
• To evaluate the efficacy of endovascular coil embolization using Guglielmi detachable coils (GDCs) and mechanical detachable coils (MDCs).
• To compare angiographic and histopathological findings for assessing aneurysm obliteration.

Main Methods:

• Microsurgical creation of bifurcation aneurysms by performing end-to-side anastomoses of common carotid arteries and attaching a venous pouch.
• Endovascular embolization of 26 aneurysms using GDCs and MDCs.
• Serial angiography and subsequent histopathological examination of embolized aneurysms.

Main Results:

• Angiography initially suggested complete obliteration in 9/26 aneurysms, but only 4/26 showed complete occlusion at follow-up.
• Histopathological examination revealed incomplete obliteration in all 17 analyzed aneurysms, including those deemed completely occluded by angiography.
• A significant overestimation of aneurysm obliteration by radiological assessment was observed.

Conclusions:

• The rabbit bifurcation aneurysm model accurately mimics human cerebral aneurysms.
• Endovascular coil embolization efficacy is often overestimated by angiography.
• Histopathological analysis is essential for accurate assessment of aneurysm treatment success.