title: Microsurgical clipping of unruptured middle cerebral artery bifurcation aneurysms: incidence of and risk factors for procedure-related complications.
abstract: OBJECTIVE
  To report our experiences in microsurgical clipping of unruptured middle cerebral artery (MCA) bifurcation aneurysms and to evaluate the incidence of and risk factors for procedure-related complications.
  
  
  METHODS
  The study comprised 416 patients treated between March 2003 and February 2014. All patients met the following criteria: 1) microsurgical clipping of an unruptured MCA bifurcation aneurysm was performed, and 2) clinical and radiographic follow-up data were available including preoperative digital subtraction angiography. The incidence of and risk factors for procedure-related complications were retrospectively evaluated.
  
  
  RESULTS
  Procedure-related complications occurred in 15 (3.6%) patients, including asymptomatic complications in 10 (2.4%) patients and symptomatic complications in 5 (1.2%) patients. Multivariate logistic regression analysis showed that posteroinferior projection of the aneurysm (odds ratio = 2.814, 95% confidence interval = 0.995-6.471, P = 0.042), distance between the internal carotid artery bifurcation and the MCA bifurcation (Dt) in a linear line (odds ratio = 1.813, 95% confidence interval = 0.808-6.173, P = 0.043), and horizontal angle between the vertical line to the base of the skull and Dt (odds ratio = 2.046, 95% confidence interval = 1.048-10.822, P = 0.048) were independent risk factors for procedure-related complications.
  
  
  CONCLUSIONS
  When performing clipping of unruptured MCA bifurcation aneurysms, the procedure-related complication rate was 3.6%. Patients with MCA bifurcation aneurysms with posteroinferior projection, shorter Dt, and larger horizontal angle may be at a higher risk of procedure-related complications when performing microsurgical clipping.
authors: Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Joonho
authors: J
authors: Chung
authors: Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Chang-Ki
authors: CK
authors: Hong
authors: Department of Neurosurgery, Inha University School of Medicine, Incheon, Republic of Korea.
authors: Yu Shik
authors: YS
authors: Shim
authors: Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Jin-Yang
authors: JY
authors: Joo
authors: Department of Neurosurgery, Ajou University School of Medicine, Suwon, Republic of Korea.
authors: Yong Cheol
authors: YC
authors: Lim
authors: Department of Neurosurgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
authors: Yong Sam
authors: YS
authors: Shin
authors: Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address: ybkim69@yuhs.ac.
authors: Yong Bae
authors: YB
authors: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D002548:Cerebral Revascularization / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D002532:Intracranial Aneurysm / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Complications; Intracranial aneurysm; Microsurgical clipping; Middle cerebral artery; Predictors; Unruptured aneurysm