title: Balloon test occlusion with hypotensive challenge for main trunk occlusion of internal carotid artery aneurysms and pseudoaneurysms.
abstract: BACKGROUND
  Balloon test occlusion of carotid artery is a useful procedure in managing patients with internal carotid aneurysms and psuedoaneurysms. Previous studies using intravenous sodium nitroprusside for hypotensive challenge yielded false-negative results for haemodynamic ischaemia, highlighting the difference between pharmacological and compensatory vasodilatory responses. We reviewed our management result of a combined approach of clinical assessment and angiographic assessment of venous drainage using intravenous labetalol for hypotensive challenge.
  
  
  METHODS
  A retrospective review of all balloon test occlusions carried in a single neurosurgical institute between August 1996 and August 2009 was carried out. Patients with internal carotid artery aneurysms and pseudoaneurysms were reviewed accordingly.
  
  
  RESULTS
  The diagnosis at the time of treatment included radiotherapy-induced internal carotid artery pseudoaneurysms in nasopharyngeal carcinoma patients (11/23, 48%), cavernous internal carotid artery giant aneurysm (6/23, 26%) and ophthalmic segment internal carotid artery giant aneurysm (4/23, 17%). Nineteen (79%) patients passed the balloon test occlusion. In the cohort of patients that passed balloon test occlusion and underwent main trunk occlusion, there were no (0/20, 0%) permanent and no (0, 0%) transient neurological complications related to a subsequent parent artery occlusion.
  
  
  CONCLUSIONS
  A combined approach of clinical assessment and angiographic assessment of venous drainage, using intravenous labetalol for hypotensive challenge, is effective in screening out patients who were at a risk for ischaemia after internal carotid artery occlusion and can serve as a guideline for the selection of patients requiring extracranial-intracranial bypass.
authors.affiliation: Division of Neurosurgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China. georgewong@surgery.cuhk.edu.hk
authors.forename: George Kwok Chu
authors.initials: GK
authors.lastname: Wong
authors.forename: Wai Sang
authors.initials: WS
authors.lastname: Poon
authors.forename: Simon
authors.initials: S
authors.lastname: Chun Ho Yu
mesh_terms: D001921:Brain / Q000098:blood supply* / Q000473:pathology; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000628:therapy*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology*; D002404:Catheterization / Q000379:methods*; D002533:Cerebral Angiography; D005260:Female; D006723:Hong Kong; D006801:Humans; D007023:Hypotension, Controlled / Q000379:methods; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000628:therapy*; D007511:Ischemia / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome