title: Endovascular treatment of small intracranial aneurysms: three alternatives to coil occlusion.
abstract: BACKGROUND
  Small intracranial aneurysms with a fundus diameter of 2 - 3 mm may rupture and are therefore potential targets for an endovascular approach in treatment. Currently available coil technology is less than optimal for the treatment of aneurysms within this size range. Even the smallest coils are sometimes too large. If such a minute coil can be introduced into a small aneurysm, the hemodynamic effect and the induced thrombosis are frequently inadequate to occlude the aneurysm sufficiently from the parent artery circulation.
  
  
  METHODS
  Three technical alternatives for the endovascular treatment of small intracranial aneurysms not suitable for coil occlusion are illustrated with the following three case descriptions.
  
  
  RESULTS
  Stent grafts are usable for the intracranial internal carotid artery and for the V4 segment. The stiffness of the stent and the high expansion pressures are the two major drawbacks. Coaxial deployment of two or more self-expanding porous stents can result in sufficient redirection of the blood flow to induce aneurysmal thrombosis. Deployment of multiple stents, however, may require several treatment sessions in order to allow for the integration of the stents into the vessel wall from session to session. A regular microcatheter can block aneurysmal inflow in aneurysms with a very narrow neck. This allows the occlusion of the aneurysm with an appropriate amount of highly concentrated, rapidly polymerizing glue. Polymer emboli may result from excessive or rapid glue injection.
  
  
  CONCLUSIONS
  The available coil technology has inherent limitations in the treatment of very small intracranial aneurysms. Liquid embolic agents and stent-based extrasaccular treatment strategies may provide solutions for these challenging lesions.
authors.affiliation: Robert Janker Klinik, Bonn, Germany. HHHenkes@aol.com
authors.forename: H
authors.initials: H
authors.lastname: Henkes
authors.forename: J
authors.initials: J
authors.lastname: Reinartz
authors.forename: H
authors.initials: H
authors.lastname: Preiss
authors.forename: E
authors.initials: E
authors.lastname: Miloslavski
authors.forename: M
authors.initials: M
authors.lastname: Kirsch
authors.forename: D
authors.initials: D
authors.lastname: Kühne
mesh_terms: D000328:Adult; D017130:Angioplasty; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D015607:Stents