EXPERIMENTAL-STUDY OF TREATMENT OF ANEURY SM BY VASCULAR ENDOPROSTHESIS

Intracranial aneurysms occur frequently with the risk of major damage. Neurosurgery or endovascular techniques can be used for treatment. Cu rrent techniques are not well adapted for aneurysms with a wide implan tation (or neck), The aim of this experimental work was to study a tec hnique for treating aneurysms which can be used for wide neck aneurysm s. A metal stent is implanted facing the neck of the aneurysm to allow occlusion, In the first part of the study, the stent was inserted alo ne, Ten aneurysms were created surgically in five dogs, The stents wer e positioned facing seven of the ten aneurysms, The stent led to immed iate occlusion of the aneurysm in six of the cases. One aneurysm remai ned patent despite the correct position of the stent, One dog develope d secondary thrombosis of the carotid. Three dogs have been followed f or sixty days after insertion of the stent. Two aneurysms thrombosed a nd one was patent. Since these results were less than satisfactory, a second part of the study was undertaken to cover the stent with a frag ment of the autologous vein. Results in five aneurysms, evaluated thre e and eight weeks after treatment, showed partial or total repermeabil ization of the aneurysms. In the third part of the study, we associate d stents and detachable coils. Twelve aneurysms of the carotid artery in pigs were thrombosed and two aneurysms were completely occluded aft er stent implantation., In the nine other cases, the aneuysms were com pletely occluded after stent implantation. In the nine other cases. th e aneurysms remained patent despite the stent and treatment was then c ompleted with a coil. Six of the animals have been followed fur thirte en weeks. One carotid artery thrombosed. In the five other cases, the carotid arteries were patent and the aneurysms were occluded at the co ntrol angiogram. Histology results showed the presence of a fibromuscu lar endothelialized neointima at the neck of the aneurysm in four of t he five cases. The technique described here could be proposed for the treatment of wide-neck aneurysms implanted low on the carotid artery i n man. Improvements should render the system mofe flexible.