title: Complex middle cerebral artery aneurysms: a new classification based on the angioarchitecture and surgical strategies.
abstract: BACKGROUND
  Because of the diversity of aneurysm morphology, complicated arterial anatomy and hemodynamic characteristics, tailored surgical treatments are required for cases of individual complex middle cerebral artery (MCA) aneurysms.
  
  
  METHODS
  During an 8-year period, 59 complex MCA aneurysms in 58 patients were treated microsurgically in our department. Complex aneurysms were defined as having large (10-24 mm in diameter) or giant (diameter ≥ 25 mm) size or non-saccular morphology (fusiform, dissecting or serpentine).
  
  
  RESULTS
  Direct clipping of the aneurysmal necks was achieved in eight patients, while reconstructive clipping was performed in 25 patients. Indirect aneurysm occlusion was performed in 25 cases, including trapping or resecting the aneurysm in four cases, trapping or resecting the aneurysm with extra-intracranial (EC) or intra-intracranial (IC) bypass in 21 cases and internal carotid artery (ICA) sacrifice with EC-IC bypass in one case. Forty-eight aneurysms (81.4%) were completely obliterated. Graft patency was confirmed in 20 of 21 cases (95.2%) with bypass. A recurrent aneurysm was detected in one case and a re-operation was performed. Two patients with Hunt-Hess grade IV aneurysms died during the perioperative period. Overall, 52 cases (88.1%) had good outcomes (Glasgow Outcome Scale ≥ 4) during the late follow-up period.
  
  
  CONCLUSIONS
  The surgical modality and strategy for treating complex MCA aneurysm are decided according to the morphology of the aneurysm, vascular anatomy and the hemodynamic characteristics of each case. Thus, we developed a new classification based on the angioarchitecture. Favorable outcomes can be achieved by treating complex MCA aneurysms with appropriate surgical modalities, strategies and techniques.
authors.affiliation: Department of Neurosurgery, Huashan Hospital of Fudan University, 12 Wulumuqi zhong Road, Shanghai 200040, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.forename: Peixi
authors.initials: P
authors.lastname: Liu
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Tian
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Gu
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.forename: Liangfu
authors.initials: L
authors.lastname: Zhou
authors.forename: Ying
authors.initials: Y
authors.lastname: Mao
mesh_terms: D000328:Adult; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000601:surgery*; D002533:Cerebral Angiography / Q000379:methods; D002548:Cerebral Revascularization / Q000379:methods; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery*; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult