title: 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: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Diagnostic and Interventional Radiology, The Sixth Affiliated People's Hospital, Medical School of Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yue-Qi
authors.initials: YQ
authors.lastname: Zhu
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Li
authors.forename: Chun
authors.initials: C
authors.lastname: Fang
authors.forename: Hua-Qiao
authors.initials: HQ
authors.lastname: Tan
authors.forename: Wu
authors.initials: W
authors.lastname: Wang
authors.forename: Pei-Lei
authors.initials: PL
authors.lastname: Zhang
authors.forename: Ying-Sheng
authors.initials: YS
authors.lastname: Cheng
authors.forename: Jian-Bo
authors.initials: JB
authors.lastname: Wang
authors.forename: Lian-Ting
authors.initials: LT
authors.lastname: Ma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000601:surgery*; D002533:Cerebral Angiography; D002648:Child; D002675:Child, Preschool; D004621:Embolization, Therapeutic / Q000009:adverse effects; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D010865:Pilot Projects; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult