title: The sheeping technique or how to avoid exchange maneuvers.
abstract: BACKGROUND
  The arteries of bifurcation aneurysms are sometimes so angulated or tortuous that an exchange maneuver is necessary to catheterize them with a balloon or stent delivery catheter. Because of the risk of distal wire perforation associated with exchange maneuvers, we sought to find an alternative technique.
  
  
  METHODS
  Our experience shows that a microcatheter tends to preferentially follow a previously placed microcatheter, even if the initial catheterization might be challenging. Accessing an artery with two microcatheters simultaneously may thus be an alternative to an exchange maneuver. Because of this tendency for catheters to behave like sheep following one another, we named this method the sheeping technique (ST). The ST consists of (a) first placing a 1.7 French microcatheter into the division branch requiring balloon or stent protection to straighten the course of the arteries in order to facilitate and (b) positioning in the same artery of a larger and stiffer balloon or stent microcatheter. Once the second balloon or stent microcatheter is in place, the first microcatheter can be pulled back and used to coil the aneurysm.
  
  
  RESULTS
  Between January 2009 and December 2012, The ST was successfully used in 208/246 procedures (85%). Conversion to an exchange maneuver was necessary in 38/246 (15%). There were no arterial perforations or ischemic events related to the handling of both microcatheters.
  
  
  CONCLUSIONS
  The sheeping technique may improve safety by replacing the need for an exchange maneuver during difficult balloon- or stent-assisted coiling.
authors: Department of Intracranial Endovascular Therapy, Alfried-Krupp Krankenhaus Hospital, Alfried-Krupp Strasse 21, Essen, 45131, Germany. rene.chapot@krupp-krankenhaus.de.
authors: René
authors: R
authors: Chapot
authors: Department of Intracranial Endovascular Therapy, Alfried-Krupp Krankenhaus Hospital, Alfried-Krupp Strasse 21, Essen, 45131, Germany.
authors: Hannes
authors: H
authors: Nordmeyer
authors: Department of Intracranial Endovascular Therapy, Alfried-Krupp Krankenhaus Hospital, Alfried-Krupp Strasse 21, Essen, 45131, Germany.
authors: Markus
authors: M
authors: Heddier
authors: Department of Intracranial Endovascular Therapy, Alfried-Krupp Krankenhaus Hospital, Alfried-Krupp Strasse 21, Essen, 45131, Germany.
authors: Aglaé
authors: A
authors: Velasco
authors: Department of Intracranial Endovascular Therapy, Alfried-Krupp Krankenhaus Hospital, Alfried-Krupp Strasse 21, Essen, 45131, Germany.
authors: Petra
authors: P
authors: Schooss
authors: Department of Intracranial Endovascular Therapy, Alfried-Krupp Krankenhaus Hospital, Alfried-Krupp Strasse 21, Essen, 45131, Germany.
authors: Michael
authors: M
authors: Stauder
authors: Department of Intracranial Endovascular Therapy, Alfried-Krupp Krankenhaus Hospital, Alfried-Krupp Strasse 21, Essen, 45131, Germany.
authors: Paul
authors: P
authors: Stracke
authors: Department of Intracranial Endovascular Therapy, Alfried-Krupp Krankenhaus Hospital, Alfried-Krupp Strasse 21, Essen, 45131, Germany.|Department of Radiology and Neuroradiology, CHUV, University Hospital of Lausanne, Rue du Bugnon 46, Lausanne, Switzerland.
authors: Pascal J
authors: PJ
authors: Mosimann
mesh_terms: D000800:Angioplasty, Balloon / Q000379:methods* / Q000706:statistics & numerical data*; D002404:Catheterization / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D061185:Mechanical Thrombolysis / Q000379:methods* / Q000706:statistics & numerical data*; D008875:Middle Aged; D015995:Prevalence; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
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