The incidence of and risk factors for ischemic complications after microsurgical clipping of unruptured middle cerebral artery aneurysms and the efficacy of intraoperative monitoring of somatosensory evoked potentials: A retrospective study

Clin Neurol Neurosurg. 2016 Dec:151:128-135. doi: 10.1016/j.clineuro.2016.10.008. Epub 2016 Oct 14.

Abstract

Objectives: Ischemic complications (ICs) account for 6.7% after microsurgical clipping of unruptured intracranial aneurysms. This study aimed to evaluate the efficacy of somatosensory evoked potential (SSEP) monitoring during microsurgical clipping of unruptured middle cerebral artery (MCA) aneurysms and evaluate the incidence of and risk factors for ischemic complications after clipping of unruptured MCA aneurysms.

Patients and methods: Herein, 1208 patients with cerebral aneurysms and treated with microsurgical clipping between May 2003 and February 2015 were enrolled. Those with multiple aneurysms, history of head trauma, subarachnoid hemorrhage, bypass and/or endovascular treatment, and intraoperative rupture were excluded. Subsequently, 411 patients with single unruptured MCA aneurysms treated with simple microsurgical clipping were enrolled. Patients were divided into two groups based on the application of SSEP monitoring during surgery.

Results: The IC rate was 0.9% and 5.6% in the SSEP and non-SSEP groups, respectively. Univariate analysis revealed that age≥62.5years, aneurysm size≥4.15mm, temporary clipping, history of hyperlipidemia and stroke, and no-SSEP monitoring were risk factors for ICs. Multivariate logistic regression analysis showed that age≥62.5years (odds ratio [OR]=7.7; 95% confidence interval [95% CI]=1.5-37.7; P=0.011), previous stroke (OR=26.8, 95% CI=2.4-289.2, P=0.007), and inversely SSEP monitoring (OR=0.14, 95% CI 0.02-0.72, P=0.019) were independent risk factors for ICs.

Conclusion: Clinicians should consider the possibility of IC during microsurgical clipping of unruptured MCA aneurysms in patient≥62.5years and/or a history of stroke. Intraoperative SSEP monitoring is an effective and feasible tool for preventing IC.

Keywords: Cerebral aneurysm; Ischemic complication; Middle cerebral artery; Somatosensory evoked potential.

MeSH terms

  • Aged
  • Brain Ischemia / epidemiology
  • Brain Ischemia / etiology*
  • Evoked Potentials, Somatosensory / physiology*
  • Female
  • Humans
  • Incidence
  • Intracranial Aneurysm / surgery*
  • Intraoperative Neurophysiological Monitoring / methods*
  • Male
  • Microsurgery / adverse effects*
  • Microsurgery / statistics & numerical data
  • Middle Aged
  • Neurosurgical Procedures / adverse effects*
  • Postoperative Complications / epidemiology
  • Postoperative Complications / etiology*
  • Retrospective Studies
  • Risk Factors
  • Treatment Outcome