Temporary vessel occlusion in cerebral aneurysm surgery guided by direct cortical motor evoked potentials

Pilot Trial on Awake Surgery for Low-Grade Arteriovenous Malformations in Speech Area and Systematic Review of the Literature

OBJECTIVE

One of the pressing constraints in the treatment of arteriovenous malformations (AVM) is the potential development of new neurologic deficits, mainly when the AVM is in an eloquent area. The risk of ischemia when an en passage arterial supply is present is not negligible. In this regard, awake surgery holds promise in increasing the safety of low-grade AVM resection.

METHODS

We conducted a pilot trial on 3 patients with low-grade AVMs affecting speech areas to evaluate the safety of awake craniotomy using Conscious Sedation. Each feeder was temporarily clipped before the section. Also, we performed a systematic review to analyze the existing data about the impact of awake surgery in eloquent AVM resection.

RESULTS

None of the 3 patients presented with neurologic deficits after the procedure. Awake craniotomy was useful in 1 case, as it allowed the detection of speech arrest during the temporal clipping of 1 of the feeders. This vessel was identified as an en passage vessel, closer to the nidus. The second attempt revealed the feeder of the AVM, which was sectioned. Systematic review yielded 7 studies meeting our inclusion criteria. Twenty-six of 33 patients included in these studies presented with AVM affecting speech area. Only 2 studies included the motor evoked potentials. Six studies used direct cortical and subcortical stimulation. In all studies the asleep-awake-asleep technique was used.

CONCLUSIONS

Awake craniotomies are safe procedures and may be helpful in avoiding ischemic complications in low-grade AVMs, either affecting eloquent areas and/or when en passage feeders are present.

Acute evacuation of 54 intracerebral hematomas (aICH) during the microsurgical clipping of a ruptured middle cerebral artery bifurcation aneurysm-illustration of the individual clinical courses and outcomes with a serial brain CT/MRI panel until 12 months

PURPOSE

In aneurysmal intracerebral hemorrhage (aICH), our review showed the lack of the patient's individual (i) timeline panels and (ii) serial brain CT/MRI slice panels through the aICH evacuation and neurointensive care until the final brain tissue outcome.

METHODS

Our retrospective cohort consists of 54 consecutive aICH patients from a defined population who acutely underwent the clipping of a middle cerebral artery bifurcation saccular aneurysm (Mbif sIA) with the aICH evacuation at Kuopio University Hospital (KUH) from 2010 to 2019. We constructed the patient's individual timeline panels since the emergency call and serial brain CT/MRI slice panels through the aICH evacuation and neurointensive care until the final brain tissue outcome. The patients were indicated by numbers (1.-54.) in the pseudonymized panels, tables, results, and discussion.

RESULTS

The aICH volumes on KUH admission (median 46 cm3) plotted against the time from the emergency call to the evacuation (median 8 hours) associated significantly with the rebleeds (n=25) and the deaths (n=12). The serial CT/MRI slice panels illustrated the aICHs, intraventricular hemorrhages (aIVHs), residuals after the aICH evacuations, perihematomal edema (PHE), delayed cerebral injury (DCI), and in the 42 survivors, the clinical outcome (mRS) and the brain tissue outcome.

CONCLUSIONS

Regarding aICH evacuations, serial brain CT/MRI panels present more information than words, figures, and graphs. Re-bleeds associated with larger aICH volumes and worse outcomes. Swift logistics until the sIA occlusion with aICH evacuation is required, also in duty hours and weekends. Intraoperative CT is needed to illustrate the degree of aICH evacuation. PHE may evoke uncontrollable intracranial pressure (ICP) in spite of the acute aICH volume reduction.

Length of Survival, Outcome, and Potential Predictors in Poor-Grade Aneurysmal Subarachnoid Hemorrhage Patients Treated with Microsurgical Clipping

BACKGROUND

Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) has been associated with severe morbidity and high mortality. It has been demonstrated that early intervention is of paramount importance. The aim of our study is to evaluate the functional outcome and the overall survival of early microsurgically treated patients.

MATERIAL AND METHODS

Poor-grade aSAH patients admitted at our institution over fifteen years (January 2008 - December 2022) were included in our retrospective study. All participants underwent brain Computed Tomography Angiography (CTA). Fisher scale was used to assess the severity of hemorrhage. All our study participants underwent microsurgical clipping, and their functional outcome was assessed with the Glasgow Outcome Scale (GOS). We used logistic regression analysis to identify any parameters associated with a favorable outcome at 12 months. Cox proportional hazard analysis was also performed, identifying factors affecting the length of survival.

RESULTS

Our study included 39 patients with a mean age of 54 years. Thirty of our participants (76.9%) were Hunt and Hess grade V, while the vast majority (94.9%) were Fisher grade 4. The observed six-month mortality rate was 48.6%. The mean follow-up time was 18.6 months. The functional outcome at six months was favorable in 6 patients (16.2%), increased to 23.5% at 12 months. Our data analysis showed that the age, as well as the employment of temporary clipping during surgery, affected the overall outcome.

CONCLUSION

Management of poor-grade aSAH patients has been dramatically changed. Microsurgical clipping provides promising results in carefully selected younger patients.

Neuromonitoring Guided Vessel Identification in Iatrogenic Arterial Injury During Meningioma Resection

Neuromonitoring is commonly used in neurosurgery and allows intraoperative assessment of functional pathways in the brain during surgery. Monitoring alerts can guide surgical decision making in real-time allowing surgeons to mitigate or avoid potential iatrogenic injury and subsequent postoperative neurologic sequelae that may result from cerebral ischemia or malperfusion. Here we present a case of a patient undergoing a right pterional craniotomy for the resection of a tumor which crosses midline with multimodal intraoperative neuromonitoring including somatosensory evoked potentials, transcranial motor evoked potentials, and visual evoked potentials. During the final portion of tumor resection, arterial bleeding was noted of unknown origin shortly followed by loss of right lower extremity motor evoked potential recordings. Motor evoked potential recordings in the right upper, and left upper and lower extremities were stable, as well as all somatosensory evoked potentials and visual evoked potentials. This distinct pattern of right lower extremity motor-evoked potential loss suggested compromise of the contralateral anterior cerebral artery and guided the surgeons to a rapid intervention. The patient awoke from surgery with moderate postoperative weakness in the affected limb that resolved to preoperative status by postoperative day 2, and back to normal strength prior to three-month follow-up. In this case the neuromonitoring data suggested compromise to the contralateral anterior cerebral artery which guided the surgeons to investigate and identify the site of vascular injury. The present case reinforces the utility of neuromonitoring in emergent surgical situations to guide surgical decision making.