Application of the Willis covered stent in the treatment of aneurysm in the cisternal segment of the internal carotid artery: a pilot comparative study with midterm follow-up.

ABSTRACT

PURPOSE: To compare the use of the Willis stent-graft versus coil embolization for complicated aneurysms in the cisternal segment of the internal carotid artery (ICA). METHODS: Thirty-four patients (19 women; mean age 46.7+/-16.8 years, range 3-79) with 36 complicated aneurysms were treated either by Willis covered stents (n = 19) or by coil embolization (n = 17). Follow-up angiography was performed to investigate aneurysm recurrence, endoleak, and parent artery stenosis. Kaplan-Meier curves were constructed to compare the freedom from recurrence and parent artery stenosis rates in both groups. Clinical follow-up data were retrospectively analyzed and categorized as fully recovered, improved, unchanged, or worsened. RESULTS: In the covered stent group, total exclusion was immediately achieved in 13 aneurysms; there were 5 minor endoleaks and 1 delivery failure. In the patients treated with coil embolization, total/near-total occlusion was achieved in 7 aneurysms, subtotal in 8, and partial in 2. Acute thrombosis occurred in 1 patient in each group, while 1 patient experienced recurrent hemorrhage after embolotherapy. Follow-up angiography (mean 14.3+/-9.4, range 3-31) revealed that 16 aneurysms were completely isolated in the stent-graft group, with only 2 mild in-stent stenoses. Eighteen months after the procedure, Kaplan-Meier analysis showed recurrence-free rates of 93.3% and 50% for the stent-graft versus coil groups, respectively; freedom from parent artery stenosis was 87.5% and 100%. Symptoms were fully eliminated in 9 patients in each group; they were improved in 3 and 5, unchanged in 2 and 2, and worsened in 1 and 0, respectively, at the end of the follow-up period. CONCLUSION: Willis stent-graft application is an alternative to treat complicated aneurysms in the cisternal segment of the ICA. In the case of a tortuous parent artery or potential side branch coverage, however, it is still not a first choice therapy.