Treatment outcomes of surgical clipping for unruptured anterior circulation aneurysm—single institute experiences in the era of neurophysiologic monitoring and endovascular treatment

Abstract

Recently, the treatment of intracranial aneurysms entered a new phase due to safe surgical tool such as neurophysiologic monitoring and challenged by endovascular treatment. To determine the safety of clipping surgery in the modern era, we reviewed our experiences of simple unruptured anterior circulation aneurysm surgery which is commonly performed in many places. We retrospectively reviewed 610 consecutive patients who were treated with surgical clipping under motor evoked potential (MEP) monitoring for a tiny to large anterior circulation aneurysm in a single institute between 2008 and 2012. MEP changes were identified in 40 cases (6.6 %). MEP deterioration was associated with remote site epidural hematoma (n = 1), anesthesia (n = 2), temporary clipping (n = 21), and permanent clipping (n = 16). Despite that no persistent MEP deterioration was noted after prompt corrective measures, 56 (9.2 %) patients showed symptomatic (n = 14) and asymptomatic (n = 42) radiologic abnormalities. Anterior cerebral artery (ACA) aneurysm was associated with a higher radiologic complication rate (Fisher's exact test, P < 0.05). Two (0.3 %) patients showed severe morbidity (mRS >2) at latest follow-up. MEP monitoring can be helpful in preventing postoperative motor deterioration but seems to have some limitations. Although the permanent morbidity rate was low, a significant clinical (2.3 %) or radiologic (9.2 %) abnormality rate was identified even in simple aneurysm clipping that should be taken into account when performing interdisciplinary treatment planning and patient counseling. Also, direct vascular monitoring or new neurophysiologic monitoring techniques are needed to reduce surgical complications, especially in ACA aneurysm surgery.

The Neuroprotective Effect of Thiopental on the Postoperative Neurological Complications in Patients Undergoing Surgical Clipping of Unruptured Intracranial Aneurysm: A Retrospective Analysis

“…A total of 83.1% of included patients were ≥ 50, thus more patients who are <50 may be needed to show the effect of age on postoperative neurological complications in this study. On the other hand, apart from this disagreement, our finding appears to be well substantiated by several studies reporting insignificant association between age and surgical outcomes [28,39,40].…”

Incidence of Postoperative Hematomas Requiring Surgical Treatment in Neurosurgery: A Retrospective Observational Study

“…The incidence of POH after elective aneurysm surgery varies between 0.1% and 2.6%. 1,[57][58][59][60][61] In our series, there was no POH after elective aneurysm surgery and the reason for such a low rate might be that in our center, elective aneurysm clippings were performed mainly by 1 highly experienced senior surgeon microneurosurgically. Although according to an older study, 8 there was no correlation between the rank of the surgeon and the occurrence of POH after craniotomy, in a newer study, there was a lower rate of surgical complications (15.8% vs. 28.6%) and surgical vascular complications (7.6% vs. 16.7%) among high-volume (clipped >40 aneurysms per annum during the study period) compared with low-volume surgeons (<40 aneurysms), but this was statistically not significant.…”

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

“…Therefore, MEP and SSEP respond better to subcortical and cortical ischemia, respectively, depending on the anatomical differences and characteristics of the pathways of both EPs (36). Additionally, given the location of the motor pathway, a lower extremity SSEP may be more sensitive to ischemia than MEP during anterior choroidal artery or ACA territory UIA clipping (19,37). Case 261 involved PC application for repairing an Acom UIA, where a decrease in lower extremity SSEP amplitude was observed as an ACA infarction.…”