title: Treatment of distal posterior cerebral artery aneurysms: a critical appraisal of the occipital artery-to-posterior cerebral artery bypass.
abstract: OBJECTIVE
  This is the largest contemporary series of distal posterior cerebral artery (PCA) aneurysms treated by use of endovascular coiling and stenting as well as surgical clipping, clip wrapping, and bypass techniques. We propose a new treatment paradigm.
  
  
  METHODS
  The location, size, type of aneurysm, clinical presentation, treatment, complications, and outcomes associated with 34 distal PCA aneurysms in 33 patients (15 females, 18 males; mean age, 44 years) were reviewed retrospectively.
  
  
  RESULTS
  The most common presenting symptom was headache in 19 (58%) followed by contralateral weakness or numbness in 6 (18%) and visual changes in 4 (12%). Eight aneurysms were giant. Of the remaining 26 aneurysms, 17 were fusiform/dissecting, 5 were saccular, and 4 were mycotic. Treatment was primarily endovascular in 22 patients, 12 of whom also had a concomitant surgical bypass procedure. Nine patients underwent microsurgical clipping, and 3 underwent combined treatment of clipping and coiling and/or stenting. There were no significant differences in outcomes between the groups (P=.078). The recurrence rate in patients undergoing coiling was 22% and 0% in patients undergoing clipping. Fourteen aneurysms (41%) involved treatment with an occipital artery-to-PCA bypass or an onlay graft. Compared with their preoperative status, these patients had significantly worse outcomes than those without a bypass (P=.013).
  
  
  CONCLUSIONS
  Bypass techniques for the treatment of distal PCA aneurysms are associated with a higher rate of complications than once thought. In our new treatment paradigm, bypass is a last resort and reserved for patients in whom balloon-test occlusion fails, who refuse parent-vessel sacrifice, and who cannot undergo primary stenting with coiling or clip wrapping.
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013-4496, USA.
authors.forename: Steve W
authors.initials: SW
authors.lastname: Chang
authors.forename: Adib A
authors.initials: AA
authors.lastname: Abla
authors.forename: Udaya K
authors.initials: UK
authors.lastname: Kakarla
authors.forename: Eric
authors.initials: E
authors.lastname: Sauvageau
authors.forename: Shervin R
authors.initials: SR
authors.lastname: Dashti
authors.forename: Peter
authors.initials: P
authors.lastname: Nakaji
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Zabramski
authors.forename: Felipe C
authors.initials: FC
authors.lastname: Albuquerque
authors.forename: Cameron G
authors.initials: CG
authors.lastname: McDougall
authors.forename: Robert F
authors.initials: RF
authors.lastname: Spetzler
mesh_terms: D000328:Adult; D002342:Carotid Artery, External / Q000601:surgery*; D002548:Cerebral Revascularization / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D020769:Posterior Cerebral Artery / Q000601:surgery*; D011859:Radiography; D012189:Retrospective Studies; D016896:Treatment Outcome