Usefulness of Intraoperative Neurophysiological Monitoring During the Clipping of Unruptured Intracranial Aneurysm: Diagnostic Efficacy and Detailed Protocol

Abstract

Background: Intraoperative neurophysiological monitoring (IONM) has been widely applied in brain vascular surgeries to reduce postoperative neurologic deficit (PND). This study aimed to investigate the effect of IONM during clipping of unruptured intracranial aneurysms (UIAs).Methods: Between January 2013 and August 2020, we enrolled 193 patients with 202 UIAs in the N group (clipping without IONM) and 319 patients with 343 UIAs in the M group (clipping with IONM). Patients in the M group were intraoperatively monitored for motor evoked potentials (MEPs) and somatosensory evoked potentials (SSEPs). Irreversible evoked potential (EP) change was defined as EP deterioration that did not recover until surgery completion. Sustained PND was defined as neurological symptoms lasting for more than one postoperative month.Results: Ten (3.1%) and 13 (6.7%) in the M and N groups, respectively, presented with PND. Compared with the N group, the M group had significantly lower occurrence rates of sustained PND [odds ratio (OR) = 0.36, 95% confidence interval (CI) = 0.13–0.98, p = 0.04], ischemic complications (OR = 0.39, 95% CI = 0.15–0.98, p = 0.04), and radiologic complications (OR = 0.40, 95% CI = 0.19–0.82, p = 0.01). Temporary clipping was an independent risk factor for ischemic complications (ICs) in the total patient group (OR = 6.18, 95% CI = 1.75–21.83, p = 0.005), but not in the M group (OR = 5.53, 95% CI = 0.76–41.92, p = 0.09). Regarding PND prediction, considering any EP changes (MEP and/or SSEP) showed the best diagnostic efficiency with a sensitivity of 0.900, specificity of 0.940, positive predictive value of 0.321, negative predictive value (NPV) of 0.997, and a negative likelihood ratio (LR) of 0.11.Conclusion: IONM application during UIA clipping can reduce PND and radiological complications. The diagnostic effectiveness of IONM, specifically the NPV and LR negative values, was optimal upon consideration of changes in any EP modality.

Clinical Usage of Different Doses of Cis-Atracurium in Intracranial Aneurysm Surgery and Its Effect on Motor-Evoked Potentials

“…Unfortunately, these conventional treatments all have many difficulties for giant intracranial aneurysms, such as huge aneurysm, thin wall, easy rupture and bleeding, wide aneurysm neck, difficult or impossible to clip. It is not suitable for tamponade, or the pituitary gland is still compressed after tamponade, and it is difficult to improve the symptoms of patients [ 17 , 18 ].…”

Can Evoked Potential Changes during the Superficial Temporal Artery-Middle Cerebral Artery Bypass Surgery Predict Postoperative Improvement of Cerebral Perfusion and Functional Status?

“…The EP modalities applied to IONM differ slightly in their coverage area. MEP is more sensitive to subcortical ischemia; on the other hand, SSEP is more sensitive to cortical ischemia [ 13 , 29 ]. The recipient vessel in STA-MCA bypass surgery is the M4 branch.…”

“…Intraoperative neurophysiological monitoring (IONM) is widely used in open cranial surgeries, mainly as a precautionary measure to detect adverse events during surgery and to minimize the neural insult through subsequent rescue interventions [ 12 , 13 ]. Many previous studies have demonstrated its efficacy in reducing instances of postoperative neurologic deficits (PND) and in the attainment of better outcomes with open cranial surgeries [ 14 , 15 , 16 ].…”

Deterioration of non-lesional side evoked potential during unilateral single unruptured intracranial aneurysm clipping: incidental finding or true warning signal?

“…In the case of EP deterioration, we performed rescue interventions according to our protocol, as des-cribed in detail previously [13]. The basic principles of rescue intervention are fast evaluation and a multidisciplinary approach when an EP change meets the warning criteria [5,14,15].…”