title: Peri-stent aneurysm formation following a stent implant for stenotic intracranial vertebral artery dissection: a technical report of two cases successfully treated with coil embolization.
abstract: BACKGROUND
  Although stenting for stenotic vertebral artery dissection (VAD) improves compromised blood flow, subsequent peri-stent aneurysm (PSA) formation is not well-known. We report two cases with PSA successfully treated with coil embolization.
  
  
  METHODS
  Three patients with stenotic intracranial VAD underwent endovascular angioplasty at our institution because they had acute infarction in posterior circulation territory and clinical evidence of hemodynamic insufficiency. In two of three patients balloon angioplasty at first session failed to relieve the stenosis, and a coronary stent was implanted. Angiography immediately after stenting showed no abnormality in case 1 and minimal slit-like projection at proximal portion of the stent in case 2.
  
  
  RESULTS
  Angiography obtained 16 months after the stenting revealed PSA in case 1. In case 2, angiography performed 3 months later showed that the projection at proximal portion enlarged and formed an aneurysm outside the stent. Because follow-up angiographies showed growth of the aneurysm in both cases, endovascular aneurysmal embolization was performed. We advanced a microcatheter into the aneurysm through the strut of existing stent and delivered detachable coils into the aneurysm lumen successfully in both cases. The post-procedural course was uneventful, and complete obliteration of aneurysm was confirmed on angiography in both cases.
  
  
  CONCLUSIONS
  Stenting for stenotic intracranial VAD may result in delayed PSA; therefore, follow-up angiographies would be necessary after stenting for stenotic intracranial arterial dissection. Coil embolization through the stent strut would be a solution for enlarging PSA.
authors.affiliation: Clinical Research Center, National Hospital Organization Nagasaki Medical Center, 2-1001-1 Kubara, Omura 856-8562, Japan. ishi_maru@yahoo.co.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Ishimaru
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Nakashima
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takahata
authors.forename: Yohjiro
authors.initials: Y
authors.lastname: Matsuoka
mesh_terms: D003251:Constriction, Pathologic / Q000150:complications / Q000601:surgery; D004621:Embolization, Therapeutic / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000209:etiology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D015607:Stents / Q000009:adverse effects*; D016896:Treatment Outcome; D020217:Vertebral Artery Dissection / Q000150:complications* / Q000601:surgery*