Clopidogrel versus newer P2Y12 inhibitors in the dual antiplatelet therapy for stent-assisted coil embolization of intracranial aneurysms: A meta-analysis.

INTRODUCTION: Stent-assisted coil embolization (SACE) for cerebral aneurysms requires dual antiplatelet therapy (DAPT), commonly clopidogrel plus aspirin is preferable to ticagrelor or prasugrel plus aspirin. However, there are few studies assessing the safety of the association of ticagrelor or prasugrel plus aspirin. OBJECTIVES: Compare the safety of newer P2Y12 inhibitors with clopidogrel in patients that underwent a SACE for cerebral aneurysms. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, we searched PubMed and Embase for studies comparing newer P2Y12 inhibitors with clopidogrel in patients undergoing DAPT for SACE. Outcomes were total number of complications, number of hemorrhagic complications, and number of thromboembolic complications both intraoperative and follow-up. A random effects model was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: We included 1026 patients from six studies. Newer P2Y12 inhibitors were used in 562 (54,77%) patients. There were no significant differences between groups in total number of complications (OR 0.80; 95% CI 0.32, 1.99; p < 0.01; I2 = 78%), in intraoperative hemorrhagic complications (OR 0.66; 95% CI 0.09, 4.71; p = 0.68; I2 = 0%), follow-up hemorrhagic complications (OR 1.23; 95% CI 0.70, 2.15; p = 0.49; I2 = 0%), intraoperative thromboembolic complications (OR 0.43; 95% CI 0.14, 1.35; p = 0.25; I2 = 24%), and in follow-up thromboembolic complications (OR 0.89; 95% CI 0.33, 2.39; p = 0.03; I2 = 59%). CONCLUSION: In patients who underwent a SACE, newer P2Y12 inhibitors showed no differences in intraoperative and follow-up complications compared with clopidogrel.

Troubleshooting the bypass: intraoperative management of initially failed anastomosis in direct cerebral revascularization surgery.

OBJECTIVE: Direct cerebral revascularization is considered as one of the most technically challenging operations in neurosurgery. Technical errors are often not identified during the case, but only after the recirculation stage, making management crucial at that time of the procedure. In this study, the authors sought to describe troubleshooting of the technical errors encountered in initially failed bypass cases. METHODS: A retrospective analysis describing a single-surgeon, single-institution experience between 2014 and 2021 was performed, based on operative reports and videos, including a 30-day follow-up period. Initially failed bypass was defined if the bypass was not patent or had a significant leak after recirculation, irrespective of the final result. RESULTS: One hundred thirty-eight bypass cases were reviewed for complex aneurysms (n = 49), moyamoya disease (n = 59), and atherosclerosis (n = 30). Fifty-one initially failed anastomoses were identified; 43 of these were the result of a technical error. Etiologies of these failed anastomoses included a clot (n = 14), vessel kinking (n = 4), spasm (n = 5), suture-related cause (n = 5), inappropriate donor or recipient (n = 3), or lack of demand (n = 8). A major leak was attributed to an uncoagulated side branch (n = 4), vessel injury due to suture/clip placement (n = 1), or inadequate suture line coverage (n = 7). Thirty-seven (86%) of 43 cases were troubleshot successfully, as salvage maneuvers included papaverine vessel massage, donor repositioning, re-anastomosis for occlusion in select cases, local hemostatic agents, and suturing or coagulating side branches in a leak. Thirty-day follow-up revealed similar rates of patency between successfully troubleshot patients (35/37) and the rest of the cases (80/87, p = 0.6). CONCLUSIONS: Three major patterns of a noncompatible bypass were found: a major leak, an acute occlusion, or a delayed occlusion. Based on the authors' experience, salvage strategies proved successful, showing an eventual high patency rate. The authors suggest a gradual, structured algorithm to address this stage in surgery that may contribute specifically to cerebrovascular neurosurgeons at the beginning of their careers.

Improvement in visual outcomes of patients with base of skull meningioma as a result of evolution in the treatment techniques in the last three decades: a systematic review.

PURPOSE: We systematically reviewed visual outcomes over the last three decades in patients undergoing treatment for base of skull (BOS) meningiomas and provide recommendations to preserve vision. METHODS: In accordance with the PRISMA guidelines for systematic reviews, a search was conducted from 6/1/2022-9/1/2022 using PubMed and Web of Science. Inclusion criteria included (1) patients treated for BOS meningiomas (2) treatment modality specified (3) specifics of surgical techniques and/or dose/fractions of radiotherapy (4) individual patient outcomes of treatment. Each study was assessed for bias based on study design and heterogeneity of results. RESULTS: A total of 50 studies were included (N = 2911). When comparing improved vision versus unchanged or worsened vision, studies investigating surgery alone published from 2006 and onward had significantly better visual outcomes compared to pre-2006 studies (p = 0.02). When comparing improved vision versus unchanged or worsened vision, studies investigating combined therapy with surgery and radiation published from 2008 and onward had significantly better visual outcomes compared to pre-2008 studies (p < 0.01). Combined modality therapy was less likely to worsen vision compared to either surgery or radiation monotherapy (p < 0.01). However, surgery and radiation monotherapy were more likely to actually improve outcomes compared to combination therapy (p < 0.01). CONCLUSION: For over a decade we have observed improvement in visual outcomes in patients managed for meningioma of BOS, likely attributing the innovation in microsurgical and more targeted and conformal radiation techniques. Combination therapy may be the safest option for preventing worsening of vision, but the highest rates of improving visual function are achieved through monotherapy when indicated.

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.

Optimization of novel exoscopic blue light filter during fluorescence-guided resection of Glioblastoma.

PURPOSE: Operative guidelines and use optimization for new surgical exoscopes are not well described in the literature. In this study, we evaluated use of the ORBEYE (Olympus) surgical exoscope system during 5-ALA fluorescence-guided resection of GBMs to optimize workflow and exoscope settings. METHODS: The ORBEYE exoscope system was fitted with a blue light filter for 5-ALA mediated fluorescence-guided surgery (FGS). Intraoperative images were obtained during 5-ALA FGS in 9 patients with primary or recurrent GBM. The exoscope was set up at constant, increasing focal distances from the target tissue, and light source intensity varied. High-resolution 4 K images were captured and analyzed. Comparisons of fluorescence to background were then generated for use optimization. RESULTS: Light intensity did not significantly influence tumor fluorescence (P = 0.878). However, focal distance significantly impacted relative fluorescent intensity (P = 0.007). Maximum average fluorescence was seen consistently at a focal length of 220 mm and a light intensity of approximately 75% maximum. Decreasing focal distance from 400 mm to 220 mm significantly increased visualized fluorescence (P = 0.0038). CONCLUSIONS: The ORBEYE surgical exoscope system with blue light filter is a powerful imaging tool for 5-ALA FGS in GBM. The ORBEYE blue filter performs optimally at shorter focal distance with moderate light intensity. Similar to microscope systems, decreasing focal distance significantly influences visualized fluorescence.

Short and long-term prognostic value of intraoperative motor evoked potentials in brain tumor patients: a case series of 121 brain tumor patients.

PURPOSE: Iatrogenic neurologic deficits adversely affect patient outcomes following brain tumor resection. Motor evoked potential (MEP) monitoring allows surgeons to assess the integrity of motor-eloquent areas in real-time during tumor resection to lessen the risk of iatrogenic insult. We retrospectively associate intraoperative transcranial and direct cortical MEPs (TC-MEPs, DC-MEPs) to early and late post-operative motor function to prognosticate short- and long-term motor recovery in brain tumor patients undergoing surgical resection in peri-eloquent regions. METHODS: We reviewed 121 brain tumor patients undergoing craniotomies with DC-MEP and/or TC-MEP monitoring. Motor function scores were recorded at multiple time-points up to 1 year postoperatively. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were calculated at each time point. RESULTS: The sensitivity, specificity, PPV, and NPV of TC-MEP in the immediate postoperative period was 17.5%, 100%, 100%, and 69.4%, respectively. For DC-MEP monitoring, the respective values were 25.0%, 100%, 100%, and 68.8%. By discharge, sensitivity had increased for both TC-MEP and DC MEPs to 43.8%, and 50.0% respectively. Subset analysis on patients without tumor recurrence/progression at long term follow-up (n = 62 pts, 51.2%) found that all patients with stable monitoring maintained or improved from preoperative status. One patient with transient intraoperative TC-MEP loss and permanent DC-MEP loss suffered a permanent deficit. CONCLUSION: Brain tumor patients who undergo surgery with intact MEP monitoring and experience new postoperative deficits likely suffer transient deficits that will improve over the postoperative course in the absence of disease progression.

Reconstruction of the Anterior Skull Base Using the Nasoseptal Flap: A Review.

The nasoseptal flap is a workhorse reconstructive option for anterior skull base defects during endonasal surgery. This paper highlights the versatility of the nasoseptal flap. After providing a brief historical perspective, this review will focus on the relevant primary literature published in the last ten years. We will touch upon new applications of the flap, how the flap has been modified to expand its reach and robustness, and some of the current limitations. We will conclude by discussing what the future holds for improving upon the design and use of the nasoseptal flap in anterior skull base reconstruction.

Exoscopic Cerebrovascular Neurosurgery.

The exoscope is the technological successor to the operating microscope in cerebrovascular neurosurgery. It offers advantages including improved operative field magnification, resolution, lighting, ergonomics, team cohesiveness, and microsurgical training However, these advantages of using the exoscope must be weighed against the learning curve during its adoption, especially for senior microneurosurgeons. As exoscope technology is refined, seamless integration of robotics, automation, augmented reality, and hands-free real-time neuronavigation is anticipated.

Deliberate Parent Artery Sacrifice Guided by Intraoperative Neurophysiological Monitoring During Complex Surgical Clipping of a Ruptured Anterior Communicating Artery Aneurysm.

Aneurysms arising from the anterior communicating artery (ACOA) are the most common intracranial aneurysms encountered. Most aneurysms can be treated with surgical clipping or endovascular coiling; however, there are times when parent vessel sacrifice (PVS) is necessary such as aneurysms with fragile necks or large/giant aneurysms. Application of intraoperative neurophysiological monitoring (IONM) can assist in guiding permissive temporary vessel occlusion during complex aneurysm clippings. However, to-date there is no literature that describes how IONM can be used as a predictor of post-operative neurological status when PVS is employed or as a guide to determine whether PVS is safe. We present a case where IONM guided the sacrifice of the A1 and anterior communicating arteries after 2 hours and 25 min of temporary vessel occlusion. No attenuation was noted in the IONM at any point during the procedure, and the IONM predicted the patient would awake neurologically intact.

Stimulated Raman histology facilitates accurate diagnosis in neurosurgical patients: a one-to-one noninferiority study.

OBJECTIVE: Stimulated Raman histology (SRH) offers efficient and accurate intraoperative neuropathological tissue analysis without procedural alteration to the diagnostic specimen. However, there are limited data demonstrating one-to-one tissue comparisons between SRH and traditional frozen sectioning. This study explores the non-inferiority of SRH as compared to frozen section on the same piece of tissue in neurosurgical patients. METHODS: Tissue was collected over a 1-month period from 18 patients who underwent resection of central nervous system lesions. SRH and frozen section analyses were compared for diagnostic capabilities as well as assessed for quality and condition of tissue via a survey completed by pathologists. RESULTS: SRH was sufficient for diagnosis in 78% of specimens as compared to 94% of specimens by frozen section of the same specimen. A Fisher's exact test determined there was no significant difference in diagnostic capability between the two groups. Additionally, both quality of SRH and condition of tissue after SRH were deemed to be non-inferior to frozen section. CONCLUSIONS: This study provides further evidence for the non-inferiority of SRH techniques. It is also the first study to demonstrate SRH accuracy using one-to-one tissue analysis in neuropathological specimens.

Complete Resolution of Skull Base Solitary Plasmacytoma Using Proton-Beam Radiotherapy: A Case Report.

Cranial solitary plasmacytomas are uncommon lesions, and localization to the skull base is rare. Here we present a case in a 36-year-old woman who complained of dizziness and mild headaches. Radiographic imaging indicated the presence of a solitary skull base lesion in the posterior cranial fossa. Laboratory tests and imaging excluded systemic disease. A biopsy of the lesion confirmed the diagnosis of plasmacytoma. The patient was treated with proton-beam radiation and had a complete clinical and radiographic resolution, demonstrating the previously unreported utility of monotherapy with proton-beam radiation in such cases.

Enhanced Recovery After Surgery (ERAS) for Cranial Tumor Resection: A Review.

Enhanced Recovery After Surgery (ERAS) protocols describe a standardized method of preoperative, perioperative, and postoperative care to enhance outcomes and minimize complication risks surrounding elective surgical intervention. A growing body of evidence is being generated as we learn to apply principles of ERAS standardization to neurosurgical patients. First applied in spinal surgery, ERAS protocols have been extended to cranial neuro-oncologic procedures. This review synthesizes recent findings to generate evidence-based guidelines to manage neurosurgical oncology patients with standardized systems and assess ability of these systems to coordinate multidisciplinary, patient-centric care efforts. Furthermore, we highlight the potential usefulness of multimedia, app-based communication platforms to facilitate patient education, autonomy, and team communication within each of the 3 settings.

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

BACKGROUND: Temporary clipping is an important tool in the vascular neurosurgeon's armamentarium. We routinely utilize intraoperative neurophysiological monitoring (IONM) for complex brain aneurysm surgery cases, relying on direct cortical motor evoked potential (DCMEP) alerts to guide the duration of temporary clipping. Previous studies have argued for relatively short and intermittent temporary clipping strategies. In this study, we sought to assess the maximal permissive temporary clipping time during complex aneurysm surgery. To do this, we assessed patient outcome in relation to temporary clip duration guided by DCMEP. METHODS: We queried our prospectively collected neuromonitoring database for anterior circulation aneurysm cases where temporary clipping was utilized by a single cerebrovascular surgeon between 2018 and 2021. Operative and IONM reports were reviewed. Patients in whom the duration of temporary clipping could not be determined were excluded. The operative strategy permissively allowed continuous temporary clipping as long as no neuromonitoring alerts were encountered. Maximal permissive parent artery occlusion time (Clipmax) was recorded as the longest duration of tolerated temporary vessel clipping without decrement in DCMEP. RESULTS: A total of 41 complex anterior circulation aneurysm clipping cases met criteria for this study. The mean Clipmax for all cases was just over 19 min and did not differ between ruptured and unruptured aneurysms. Initial alert times were not found to be predictive of final permissive temporary clip duration after re-perfusion. In 100% (41/41) of cases, the aneurysm was completely clip occluded without residual on catheter angiogram. Stable or improved modified Rankin Score was achieved in 98% (40/41) of cases at 3-month follow-up. CONCLUSIONS: This study demonstrates that using DCMEP can facilitate relatively long but safe temporary clipping durations in complex anterior circulation aneurysm surgery. In the endovascular era with only a limited subset of technically challenging aneurysms needing open surgical treatment, extended permissive temporary clipping guided by DCMEPs can significantly enhance a surgeon's ability to achieve excellent technical and clinical outcomes.

Femoral nerve neuromonitoring for lateral lumbar interbody fusion surgery.

BACKGROUND CONTEXT: The transpsoas lateral lumbar interbody fusion (LLIF) technique is an effective alternative to traditional anterior and posterior approaches to the lumbar spine; however, nerve injuries are the most reported postoperative complication. Commonly used strategies to avoid nerve injury (eg, limiting retraction duration) have not been effective in detecting or preventing femoral nerve injuries. PURPOSE: To evaluate the efficacy of emerging intraoperative femoral nerve monitoring techniques and the importance of employing prompt surgical countermeasures when degraded femoral nerve function is detected. STUDY DESIGN/SETTING: We present the results from a retrospective analysis of a multi-center study conducted over the course of 3 years. PATIENT SAMPLE: One hundred and seventy-two lateral lumbar interbody fusion procedures were reviewed. OUTCOME MEASURES: Intraoperative femoral nerve monitoring data was correlated to immediate postoperative neurologic examinations. METHODS: Femoral nerve evoked potentials (FNEP) including saphenous nerve somatosensory evoked potentials (snSSEP) and motor evoked potentials with quadriceps recordings were used to detect evidence of degraded femoral nerve function during the time of surgical retraction. RESULTS: In 89% (n=153) of the surgeries, there were no surgeon alerts as the FNEP response amplitudes remained relatively unchanged throughout the surgery (negative group). The positive group included 11% of the cases (n=19) where the surgeon was alerted to a deterioration of the FNEP amplitudes during surgical retraction. Prompt surgical countermeasures to an FNEP alert included loosening, adjusting, or removing surgical retraction, and/or requesting an increase in blood pressure from the anesthesiologist. All the cases where prompt surgical countermeasures were employed resulted in recovery of the degraded FNEP amplitudes and no postoperative femoral nerve injuries. In two cases, the surgeons were given verbal alerts of degraded FNEPs but did not employ prompt surgical countermeasures. In both cases, the degraded FNEP amplitudes did not recover by the time of surgical closure, and both patients exhibited postoperative signs of sensorimotor femoral nerve injury including anterior thigh numbness and weakened knee extension. CONCLUSIONS: Multimodal femoral nerve monitoring can provide surgeons with a timely alert to hyperacute femoral nerve conduction failure, enabling prompt surgical countermeasures to be employed that can mitigate or avoid femoral nerve injury. Our data also suggests that the common strategy of limiting retraction duration may not be effective in preventing iatrogenic femoral nerve injuries.

Middle Meningeal Artery Embolization and the Treatment of a Chronic Subdural Hematoma.

Chronic subdural hematoma (cSDH) is a common pathology that typically affects the elderly. It is believed to occur due to injury to the dural border cells, which creates an inflammation/proliferation reaction. Ineffective repair leads to the formation of a new external layer of cells and fragile capillaries, which damage easily and can worsen the condition. Conventionally, asymptomatic cSDH is managed by observation, and symptomatic cases are treated by surgical evacuation. Unfortunately, recurrence rates of the SDH following surgical evacuation can be high. One treatment option for SDH involves embolization of the middle meningeal artery (MMA). The MMA provides blood supply to the dura mater and feeds the membrane capillaries covering the SDH. MMA embolization blocks the blood flow to this system and can promote hematoma resolution. In this paper, we review the existing literature on MMA embolization and discuss the underlying pathophysiology of cSDH.

Technical aspects and operative nuances using a high-definition 4K-3-dimensional exoscope for carotid endarterectomy surgery.

PURPOSE: Carotid endarterectomy (CEA) is effective in treating carotid artery stenosis to prevent stroke. Historically, this operation has been performed utilizing loupe magnification with or without the operating microscope (OM). However, there remains a need for continued improvement in operative visualization and surgical ergonomics. Recently, newly developed digital 'exoscope' has provided the surgeon with unique lighting and magnification as well as improvements in surgical ergonomics and working angle. We sought to review our cumulative experience using a novel 4K high-definition (4K-HD) 3-dimensional (3D) exoscope (EX) for CEA surgery. METHODS: All CEA surgery cases at our institution between 2013 and 2019 using the 4K-HD 3D EX were reviewed. Operative parameters, patient outcome and operator's assessment of the EX compared to OM-assisted cases was conducted. RESULTS: 28 patients were treated, 10 of which were operated using the EX. All procedures were performed without perioperative complications, or significant differences in operative parameters (blood loss <20 cm3 and 164 ± 49.5 minutes) compared to OM-assisted cases. Operators reported improved level of comfort performing 'high' bifurcation surgery and improved visualization and posture during inspection of the distal ICA lumen as primary advantages of EX-assisted CEA over OM-assisted CEA. CONCLUSIONS: The ORBEYE EX, albeit a learning curve necessitating a short period of the OR team, provided safety and outcome comparable to OM-assisted surgery. Potential advantages noted were improved visualization and ergonomics specifically for when extreme working angles were required. Our experience suggests that the exoscope may become a valuable alternative to standard magnification tools in CEA surgery.

Electrophysiologic Mapping of the Extraocular Motor Nuclei.

Mapping the floor of the fourth ventricle to identify the motonuclei of cranial nerves VII-XII has been well-described. Though there are some reports of stimulating the pontomesencephalic surface to identify the extraocular motor nuclei, there is a debate as to its efficacy and utility in helping to identify safe entry zones for medullary incision in an intra-axial resection. We present two cases where we positively and negatively mapped the surface of the midbrain and rostral pons to assist in surgical decision-making. Both patients had gross total resections of cavernomas, and both awoke without any new onset extraocular motor deficits.

Tarlov Cyst Rupture and Intradural Hemorrhage Mimicking Intraspinal Carcinomatosis.

Lumbosacral Tarlov cysts (TCs) have rarely been seen to rupture. Here, we report an unusual presentation of a ruptured TC with intraspinal hemorrhage mimicking carcinomatosis. Pathological diagnosis was obtained using percutaneous biopsy. A conservative approach was utilized and an excellent outcome was achieved. Thus, in cases such as this, a ruptured hemorrhagic TC should be on the differential diagnosis to drive appropriate clinical management decisions.

Asleep Speech Mapping Using Orofacial Muscles as Surrogates for Motor Speech in Patients Who Cannot Tolerate Awake Surgery: A Case Series.

Background Bi-polar electrical cortical stimulation during awake craniotomy has been the gold standard for mapping eloquent cortex to preserve speech. Unfortunately, not all patients can tolerate awake surgery. Monopolar hi-frequency electrical stimulation can be conducted while a patient is under general anesthesia. Utilizing this technique and targeting the orofacial muscles as surrogates for motor speech may provide a limited alternative to awake cortical mapping in patients unable to undergo surgery awake. Objective To evaluate the utility of asleep motor speech mapping during dominant hemisphere craniotomy for lesion resection in patients who cannot tolerate awake surgery. Methods We describe a series of seven patients who underwent craniotomy for resection of intra-axial lesion in eloquent cortex for whom a novel "asleep speech" cortical stimulation paradigm was used for motor speech preservation. Results Compound muscle action potentials (CMAPs) from orofacial muscles involved in motor speech were recorded during direct cortical stimulation of eloquent cortex prior to and during lesion resection. Planned resections proceeded in all cases with no adverse neuromonitoring events. Speech was preserved in all patients. Conclusions To preserve motor speech functionality in patients unable to tolerate awake speech mapping, we employed a technique in which asleep neurophysiological mapping is specifically applied to motor cortex controlling the orofacial muscles of phonation and articulation. Further study is necessary regarding the safety and efficacy of this technique for motor speech preservation when awake surgery cannot be performed.