Cerebrovascular Surgery Research Articles

Cerebrovascular surgery: from the Wild West through the endovascular revolution. The M. Gazi Yaşargil Lecture at the American Association of Neurological Surgeons 2021 Annual Scientific Meeting.

"Cerebrovascular surgery: from the Wild West through the endovascular revolution. The M. Gazi Yaşargil Lecture at the American Association of Neurological Surgeons 2021 Annual Scientific Meeting" published on 07 Jan 2022 by American Association of Neurological Surgeons.

Clipping versus coiling for treatment of middle cerebral artery aneurysms: a retrospective Italian multicenter experience

Endovascular treatment has emerged as the predominant approach in intracranial aneurysms. However, surgical clipping is still considered the best treatment for middle cerebral artery (MCA) aneurysms in referral centers. Here we compared short- and long-term clinical and neuroradiological outcomes in patients with MCA aneurysms undergoing clipping or coiling in 5 Italian referral centers for cerebrovascular surgery. We retrospectively reviewed 411 consecutive patients admitted between 2015 and 2019 for ruptured and unruptured MCA aneurysm. Univariate and multivariate analyses of the association between demographic, clinical, and radiological parameters and ruptured status, type of surgical treatment, and clinical outcome at discharge and follow-up were performed. Clipping was performed in 340 (83%) cases, coiling in 71 (17%). Clipping was preferred in unruptured aneurysms and in those showing collateral branches originating from neck/dome. Surgery achieved a higher rate of complete occlusion at discharge and follow-up. Clipping and coiling showed no difference in clinical outcome in both ruptured and unruptured cases. In ruptured aneurysms age, presenting clinical status, intracerebral hematoma at onset, and treatment-related complications were significantly associated with outcome at both short- and long-term follow-up. The presence of collaterals/perforators originating from dome/neck of the aneurysms also worsened the short-term clinical outcome. In unruptured cases, only treatment-related complications such as ischemia and hydrocephalus were associated with poor outcome. Clipping still seems superior to coiling in providing better short- and long-term occlusion rates in MCA aneurysms, and at the same time, it appears as safe as coiling in terms of clinical outcome.

Letter to the Editor “Challenges of Meeting Cerebrovascular Surgery Demands in Low-and Middle-Income Countries: An Experience from Iraq”

The endoscopic endonasal approach (EEA) was originally performed to treat thyroid orbitopathy and proptosis. Since then, this approach also has been used to treat other causes of proptosis. This review systematically identifies surgical outcome and complication rates in patients without thyroid proptosis who underwent endoscopic endonasal orbital decompression.Databases were searched using the following search terms: orbital disease, surgical decompression, and endoscopic endonasal approach. Two independent reviewers screened all abstracts and titles for relevance and all articles passing this screen were subjected to full-text review. To assess risk of bias, we used ROBINS-I (Risk Of Bias in Non-randomized Studies–of Interventions).Eight studies with a total of 74 patients with nonthyroid proptosis were included. Pre- and postoperative eye examination was performed in all studies, but the extent of examination was varying. With a mean age of 35.7 years, most patients were adolescent, and most pathologies induced unilateral proptosis Complications to EEA for orbital decompression were transient diplopia (5 patients/6.8%), transient facial dysesthesia (2 patients/2.7%), ptosis (1 patient/1.4%), infarction (1 patient/1.4%), sinus obstruction (1 patient/1.4%), and enophtalmos (1 patient/1.4%). The authors reported successful reduction of proptosis in all but 2 patients (97.2%), and only 2 authors reported a need for secondary decompression.Medial orbital decompression using EEA is a feasible approach for orbital decompression in patients with nonthyroid proptosis. While being comparable in primary outcome to transorbital approaches, the EEA seems superior in terms of complication rates

Preoperative Serum Alkaline Phosphatase and Neurological Outcome of Cerebrovascular Surgery.

This study evaluated the relationship between the preoperative alkaline phosphatase (ALP) level and major postoperative neurological complications in patients undergoing cerebral bypass surgery. This was a retrospective analysis of a prospective database of all patients undergoing cerebral bypass surgery after a diagnosis of cerebrovascular stenosis or occlusion between May 2003 and August 2017. The patients were divided into tertiles based on serum alkaline phosphatase (ALP) levels (low: <63, intermediate: 63~79, and high: ALP > 79 IU/mL). The incidence of neurological events according to ALP level was analyzed. The study analyzed 211 cases. The incidence of acute infarction was highest in the third serum ALP tertile (5.7% vs. 2.9% vs. 16.9% in the first, second, and third tertile, respectively, p = 0.007). Logistic regression analysis showed that the third tertile of serum ALP was an independent predictor of acute cerebral infarction (odds ratio 3.346, 95% confidence interval 1.026–10.984, p = 0.045). On Kaplan–Meier time-to-event curves, the incidence of acute infarction increased significantly with ALP (log rank = 0.048). Preoperative serum ALP level can be used as a biomarker to predict acute cerebral infarction in patients undergoing cerebral bypass surgery for vascular stenosis or occlusion.

Cerebral Bypass Using the Descending Branch of the Lateral Circumflex Femoral Artery: A Case Series.

When performing extracranial to intracranial (EC-IC) and intracranial to intracranial (IC-IC) bypass, the choice of donor vessel and interposition graft depends on several factors: vessel size and accessibility, desired blood flow augmentation, revascularization site anatomy, and pathology. The descending branch of the lateral circumflex femoral artery (DLCFA) is an attractive conduit for cerebrovascular bypass. To present our institutional experience using DLCFA grafts for cerebral revascularization. Retrospective review of perioperative data and outcomes for patients undergoing cerebrovascular bypass surgery using a DLCFA graft from 2016 to 2019. Twenty consecutive patients underwent EC-IC bypass using a DLCFA interposition graft. Bypass indications included 13 (65%) intracranial aneurysms, 4 (20%) medically refractory atherosclerotic large artery occlusions (internal carotid artery or middle cerebral artery), 2 (10%) internal carotid artery dissections, and 1 (5%) patient with moyamoya disease. Most commonly, a donor superior temporal artery was bypassed to a recipient middle cerebral artery (14 of 20; 70%). Two cases demonstrated graft spasm. Graft occlusion occurred in one patient and was asymptomatic. Perioperative bypass surgery-related ischemia occurred in 3 patients: 1 patient with insufficient bypass flow, 1 patient with graft stenosis because of an adventitial band, and 1 patient with focal status epilepticus in the bypassed territory resulting in cortical ischemia. One donor site hematoma occurred. The median (range) modified Rankin scale (mRS) score on follow-up was 1.5 (1-4) at 7.8 (1-27) months, with most patients achieving good functional outcomes (mRS ≤2). The DLCFA is a versatile graft for cerebral revascularization surgery, demonstrating good outcomes with minimal graft harvest site morbidity and an acceptable graft patency rate.

Temporary arterial occlusion (TAO) as independent prognostic factor in unruptured aneurysm surgery: A cohort study

BackgroundTemporary arterial occlusion (TAO) is a technique widely used in cerebrovascular surgery. However, few studies have evaluated the independent long-term effects of TAO or given detailed information about the complications during in-hospital stay. ObjectiveThis study aims to investigate the independent impact of TAO during unruptured intracranial aneurysm surgery on short and long-term outcomes. MethodsThe study included surgical elective patients diagnosed with unruptured aneurysm and indication of microsurgical treatment. Outcome assessment included occurrence of intra-operative (IOC) and post-operative (POC) complications, as well as Glasgow Outcome Scale (GOS) score 6 months after discharge. Results114 patients were included and 36 were followed. TAO was associated with POC (OR = 2.08; CI 95% 1.12–3.96; p = 0.01). The group with TAO and intraoperative rupture (IOR) did not differ from the group with TAO without IOR in terms of POC (p = 0.65) and IOC (p = 0.78). IOR (p = 0.16) and number of occlusions (p = 0.23) did not change GOS, but the total time of occlusion was associated with neurologic worsening (p = 0.034) during follow-up. The TAO group had larger aneurysm size and higher frequency of irregular lesions, when compared to the entire study group. Aneurysm location was not associated with POC (p = 0.25), IOC (0.17) or GOS (p = 0.75). ConclusionThe location of temporary clip placement and the number of clips did not influence the short- and long-term outcomes of patients with unruptured intracranial aneurysms. However, presence of temporary clips was associated with POC regardless of IOR occurrence and increased total time of occlusion was associated with poor outcomes after 6 months.

301 1000 Cases of Surgically Treated Aneurysmal Subarachnoid Haemorrhage: Changes in Practice and Clinical Outcomes

INTRODUCTION: Aneurysmal subarachnoid haemorrhage (aSAH) remains a complex and multidisciplinary pathology. With endovascular methods expanding fewer patients are treated surgically. METHODS: All patients following surgery for aSAH between 2007 - 2019 were included. Baseline characteristics outcomes were analysed. We compared outcomes between experienced (=50 independent cases) and non-experienced surgeons (&lt;50 independent cases), and high-volume (=20 cases/year) and low-volume surgeons (&lt;20 cases/year). RESULTS: 970 patients with 1003 aneurysms were identified with median age 56. 73.8% were WFNS grade 1 or 2. The majority of aneurysm were on the middle cerebral artery (41.4%), anterior communicating artery (27.6%) and posterior communicating artery (17.5%). 37.4% of aneurysm were &lt;7 mm in size. Technical error rate was 6%, resulting in a post-operative infarct in 4.9% of patients. 19 patients (2%) died within 30 days of admission. There were no significant changes in technical error rates or post-operative infarcts or death (p = 0.79 and p = 0.77 respectively) over the study period. There was no difference in post-operative infarctions between experienced and non-experienced surgeons (p = 0.28), but there was a difference when comparing high-volume vs. low-volume surgeons (p = 028). CONCLUSION: We present real world data on surgical indications and outcomes after aSAH. We believe that this constitutes important data demonstrating good retention of skills and good clinical outcomes in a very dynamic field of cerebrovascular surgery. We also demonstrate a relationship between surgical case volume and outcomes.

Multidisciplinary collaboration-based nursing for a patient undergoing percutaneous transluminal coronary angioplasty combined with cerebrovascular interventional surgery

Multidisciplinary collaboration-based nursing for a patient undergoing percutaneous transluminal coronary angioplasty combined with cerebrovascular interventional surgery

Current status of augmented reality in cerebrovascular surgery: a systematic review.

Augmented reality (AR) is an adjuvant tool in neuronavigation to improve spatial and anatomic understanding. The present review aims to describe the current status of intraoperative AR for the treatment of cerebrovascular pathology. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following databases were searched: PubMed, Science Direct, Web of Science, and EMBASE up to December, 2020. The search strategy consisted of "augmented reality," "AR," "cerebrovascular," "navigation," "neurovascular," "neurosurgery," and "endovascular" in both AND and OR combinations. Studies included were original research articles with intraoperative application. The manuscripts were thoroughly examined for study design, outcomes, and results. Sixteen studies were identified describing the use of intraoperative AR in the treatment of cerebrovascular pathology. A total of 172 patients were treated for 190 cerebrovascular lesions using intraoperative AR. The most common treated pathology was intracranial aneurysms. Most studies were cases and there was only a case-control study. A head-up display system in the microscope was the most common AR display. AR was found to be useful for tailoring the craniotomy, dura opening, and proper identification of donor and recipient vessels in vascular bypass. Most AR systems were unable to account for tissue deformation. This systematic review suggests that intraoperative AR is becoming a promising and feasible adjunct in the treatment of cerebrovascular pathology. It has been found to be a useful tool in the preoperative planning and intraoperative guidance. However, its clinical benefits remain to be seen.

A novel method for quantitative evaluation of motor evoked potential monitoring during cerebrovascular surgeries

Transcranial motor evoked potential (MEP) monitoring, intended to assess cerebral cortical ischemia, may produce false negative results when the stimulation inadvertently activates the deep, subcortical motor pathways. This study examined hand MEP onset latency as a potential means to differentiate superficial versus deep stimulus penetration in surgical patients monitored for cerebral ischemia.Intraoperative MEP data were prospectively collected from 40 patients treated for intracranial aneurysm or carotid stenosis. Onset latencies of hand MEP responses were measured over a range of stimulation intensities from both the contralateral and ipsilateral hand (crossover responses). At the threshold for superficial, cortical stimulation of the contralateral hand, the MEP latency was 26.9 ± 0.4 ms. MEP onset latencies measurements became shorter as stimulation intensities were increased. At the maximum intensity (when crossover response was usually generated), the contralateral hand MEP latency of 22.5 ± 0.3 ms was significantly shorter than at threshold stimulation (p < 0.001). Latency-stimulus intensity plots best fit a 3 parameter hyperbolic decay function (r2 = 0.85 ± 0.02) and revealed a narrow window of acceptable MEP stimuli to obtain superficial cortical activation. Our analysis refutes the utility of the crossover response in reliably gauging depth of activation. Additionally, we found that differentiation between long and short MEP onset latency times may serve as a dependable marker for depth of stimulation. Attention to hand MEP onset latency may reduce inadvertent stimulation of the deep corticospinal tract pathways and avoid false negative MEP recordings during cerebrovascular surgeries.

An innovative, reusable, high-fidelity neurosurgical training simulator for cerebrovascular bypass surgery: Iatrotek®didactic platform validation study and systematic Literature review

An innovative, reusable, high-fidelity neurosurgical training simulator for cerebrovascular bypass surgery: Iatrotek®didactic platform validation study and systematic Literature review

Assessment of the incidence and nature of adverse events and their association with human error in neurosurgery. A prospective observation

IntroductionAdverse events in surgery are a relevant cause of costs, disability, or death, and their incidence is a key quality indicator that plays an important role in the future of health care. In neurosurgery, little is known about the frequency of adverse events and the contribution of human error. Research questionTo determine the incidence, nature and severity of adverse events in neurosurgery, and to investigate the contribution of human error. Material and methodsProspective observation of all adverse events occurring at an academic neurosurgery referral center focusing on neuro-oncology, cerebrovascular and spinal surgery. All 4176 inpatients treated between September 2019 and September 2020 were included. Adverse events were recorded daily and their nature, severity and a potential contribution of human error were evaluated weekly by all senior neurosurgeons of the department. Results25.0% of patients had at least one adverse event. In 25.9% of these cases, the major adverse event was associated with human error, mostly with execution (18.3%) or planning (5.6%) deficiencies. 48.8% of cases with adverse events were severe (≥SAVES-v2 grade 3). Patients with multiple adverse events (8.6%) had more severe adverse events (67.6%). Adverse events were more severe in cranial than in spinal neurosurgery (57.6 vs. 39.4%). Discussion and conclusionAdverse events occur frequently in neurosurgery. These data can serve as benchmarks when discussing quality-based accreditation and reimbursement in upcoming health care reforms.The high frequency of human performance deficiencies contributing to adverse events shows that there is potential to further eliminate avoidable patient harm.

Clinical Applications of Additive Manufacturing Models in Neurosurgery: a Systematic Review

Abstract Introduction Three-dimensional (3D) printing technologies provide a practical and anatomical way to reproduce precise tailored-made models of the patients and of the diseases. Those models can allow surgical planning, besides training and surgical simulation in the treatment of neurosurgical diseases. Objective The aim of the present article is to review the scenario of the development of different types of available 3D printing technologies, the processes involved in the creation of biomodels, and the application of those advances in the neurosurgical field. Methods We searched for papers that addressed the clinical application of 3D printing in neurosurgery on the PubMed, Ebsco, Web of Science, Scopus, and Science Direct databases. All papers related to the use of any additive manufacturing technique were included in the present study. Results Studies involving 3D printing in neurosurgery are concentrated on three main areas: (1) creation of anatomical tailored-made models for planning and training; (2) development of devices and materials for the treatment of neurosurgical diseases, and (3) biological implants for tissues engineering. Biomodels are extremely useful in several branches of neurosurgery, and their use in spinal, cerebrovascular, endovascular, neuro-oncological, neuropediatric, and functional surgeries can be highlighted. Conclusions Three-dimensional printing technologies are an exclusive way for direct replication of specific pathologies of the patient. It can identify the anatomical variation and provide a way for rapid construction of training models, allowing the medical resident and the experienced neurosurgeon to practice the surgical steps before the operation.

Three-Dimensional Reconstruction of Cerebrovascular and Algorithm Realization.

Objective In the three-dimensional reconstruction of CT cerebrovascular medical image registration, a new optimization algorithm based on the relative position information between the contours of various blood vessels in the image is proposed. Methods Using the rule that the center of gravity of the vascular tissue structure on the series of slices has continuity, find the registration relationship between the contours of the vessels in the two adjacent slices. Because the shape of cerebrovascular contour is relatively symmetrical, its center of gravity is slightly away from its geometric center. Therefore, the geometric center is used to replace the center of gravity, and the “mass” of each contour is calculated according to the area of each contour to achieve the registration of the blood vessel contour. Results The method has the characteristics of global optimization and stronger robustness. Conclusion The cerebrovascular image obtained by this method is more realistic and can be used for the import of various software, simulation training, and later research, which provides an effective method for preoperative simulation of cerebrovascular intervention surgery.

Needle Parking Interrupted Suturing Technique for Microvascular Anastomosis: A Technical Note.

Interrupted and continuous suturing are 2 common techniques for microvascular anastomosis in cerebrovascular surgery. One of the technical complexities of interrupted suturing includes the risk of losing the needle in between interrupted sutures during knot tying, which may result in unnecessary movements and wasted time. To report a new needle parking technique for microvascular anastomosis that addresses a needle control problem during interrupted suturing. The needle parking technique involves puncturing both vessel walls at the site of the next provisional suture and leaving the needle parked in place while the knots at the first suture are being made. The thread is then cut, the needle is pulled through, and the process is repeated. Illustrative cases in which the needle parking technique was used are presented. We also compared time of anastomosis completion between the conventional interrupted, needle parking interrupted, and continuous suturing techniques during an in vitro study on standardized artificial vessels. This technique is being used successfully by the senior author for various cerebrovascular bypass surgeries. The in vitro study demonstrated that the needle parking technique can be significantly faster than the conventional interrupted suturing technique and may be as fast as continuous suturing. Needle parking technique is a modification of conventional interrupted suturing and solves the problem of losing the needle during knot tying. This technique is simple, prevents unnecessary movements, and may result in a faster anastomosis time.

Symposium 5: Intraoperative Neurophysiological Monitoring (NIOM) SY5.1. Intraoperative neuromonitoring for cerebrovascular surgery

Background and objective . Cerebrovascular diseases are one of the most popular filed of neurosurgery. The most frequent procedure is clipping surgery for intracranial aneurysms (ICAns). Arteriovenous malformation (AVM) is also the lesion for which intraoperative neurmonitoring (IOM) play important role as well as for carotid endoarterectomy (CEA) and carotid artery stenting (CAS). Intraoperative neuromonitoring (IOM) plays indispensable role to reduce the surgical risks. Here, IOM for these cerebrovascular surgeries is presented. IOM of intracranial aneurysms clipping surgery The IOM play a crucial role to preserve neuronal tracts such as corticospinal tract (CST). Motor evoked potential (MEP) is the most sensitive modality for monitoring CST, especially for anterior choroidal artery and lenticulostriate arteries. Somatosensory evoked potential (SSEP) can detect ischemia in broader area of cerebral cortex than MEP. It is important to understand each surgical step, so that neuromonitoring alteration can sometimes be anticipated. Temporary occlusion of proximal parent artery is frequently used, and the safe obliteration time varies case by case. IOM can advise on this issue. Obliteration of aneurysm and preserved patency of the relevant vessels need be confirmed by supportive technique including IOM, intraoperative video angiography and Doppler flowmetry. IOM of AVM surgery . Surgery of AVM is one of the most complicated procedures in neurosurgery. Surgical risk is calculated and classified by Spetzler-Martin grading system (nidus location: eloquent or non- eloquent, size: <3 cm, 3–6 cm, >6 cm, and draining system: superficial only or deep). Surgical resection of the nidus is the primary goal for AVM treatment; however, multimodality treatment strategy is considered for each case. IOM can detect ischemia of normal structure in subcortical and cortical area to reduce surgical risk. IOM in CEA and CAS. IOM includes EEG, SEP, MEP, near infra-red spectroscopy in CEA and CAS, and can detect the ischemia during proximal carotid artery occlusion and may detect embolic ischemia. Some pitfall exists, however, in each modality, so care need to be paid these aspects. Conclusions. IOM in cerebrovascular surgery is reviewed. Sudden IOM alteration indicates ischemia of neural structure, which might lead formidable consequence. The IOM plays a crucial role in cerebrovascular surgery.

Intraoperative indocyanine green video angiography (ICG\u2013VA) with FLOW 800 software in complex intracranial aneurysm surgery

BackgroundIndocyanine green video angiography (ICG–VA) is a safe and effective instrument to assess changes in cerebral blood flow during cerebrovascular surgery. After ICG-VA, FLOW 800 provides a color-coded map to directly observe the dynamic distribution of blood flow and to calculate semiquantitative blood flow parameters later. The purpose of our study is to assess whether FLOW 800 is useful for surgery of complex intracranial aneurysms and to provide reliable evidence for intraoperative decision-making.MethodsWe retrospectively reviewed patients with complex aneurysms that underwent microsurgical and intraoperative evaluation of ICG-VA and FLOW 800 color-coded maps from February 2019 to May 2020. FLOW 800 data were correlated with patient characteristics, clinical outcomes, and intraoperative decision-making.ResultsThe study included 32 patients with 42 complex aneurysms. All patients underwent ICG-VA FLOW 800 data provided semiquantitative data regarding localization, flow status in major feeding arteries; color maps confirmed relative adequate flow in parent, branching, and bypass vessels.ConclusionsFLOW 800 is a useful supplement to ICG-VA for intraoperative cerebral blood flow assessment. ICG-VA and FLOW 800 can help to determine the blood flow status of the parent artery after aneurysm clipping and the bypass vessels after aneurysm bypass surgery.

In Reply: Immersive 3-Dimensional Virtual Reality Modeling for Case-Specific Presurgical Discussions in Cerebrovascular Neurosurgery.

Background Adequate surgical planning includes a precise understanding of patient-specific anatomy and is a necessity for neurosurgeons. Although the use of virtual reality (VR) technology is emerging in surgical planning and education, few studies have examined the effectiveness of immersive VR during surgical planning using a modern head-mounted display. Objective To investigate if and how immersive VR aids presurgical discussions of cerebrovascular surgery. Methods A multiuser immersive VR system, BananaVisionTM, was developed and used during presurgical discussions in a prospective patient cohort undergoing cerebrovascular surgery. A questionnaire/interview was administered to multiple surgeons after the surgeries to evaluate the effectiveness of the VR system compared to conventional imaging modalities. An objective assessment of the surgeon's knowledge of patient-specific anatomy was also conducted by rating surgeons' hand-drawn presurgical illustrations. Results The VR session effectively enhanced surgeons' understanding of patient-specific anatomy in the majority of cases (83.3%). An objective assessment of surgeons' presurgical illustrations was consistent with this result. The VR session also effectively improved the decision-making process regarding minor surgical techniques in 61.1% of cases and even aided surgeons in making critical surgical decisions about cases involving complex and challenging anatomy. The utility of the VR system was rated significantly higher by trainees than by experts. Conclusion Although rated as more useful by trainees than by experts, immersive 3D VR modeling increased surgeons' understanding of patient-specific anatomy and improved surgical strategy in certain cases involving challenging anatomy.

Prophylactic Intra-Arterial Injection of Lidocaine Prevents Trigeminocardiac Reflex During Endovascular Embolization for Dural Arteriovenous Fistula: A Report of 2 Cases

Case seriesPatients: Male, 56-year-old • Male, 57-year-oldFinal Diagnosis: Trigeminocardiac reflexSymptoms: Bradycardia • severe hemodynamic fluctuationMedication: —Clinical Procedure: —Specialty: Anesthesiology • NeurosurgeryObjective:Unusual clinical courseBackground:Trigeminocardiac reflex (TCR) is a unique brain stem reflex that manifests as the sudden onset of hemodynamic perturbation in heart rate and blood pressure as a result of stimulation of any branches of the trigeminal nerve. Onyx™ embolization in cerebrovascular interventional surgery can trigger TCR, leading to severe hemo-dynamic fluctuations and even cardiac arrest. Appropriate prophylactic approaches to prevent Onyx™ embolization-induced TCR are still lacking.Case Reports:We report the cases of 2 patients with recurrent and profound bradycardia due to TCR during endovascular Onyx™ embolization for a dural arteriovenous fistula. Prophylactic intra-arterial injection of lidocaine (10–20 mg) effectively and safely blocked the recurrence and potential occurrence of TCR. These 2 patients had reduced heart rate with either hypotension or hypertension during their TCR episodes, suggesting that stimulating a distinct cerebral artery (occipital artery versus vertebral artery branch) can initiate TCR by provoking the vagus nerve via the common neuronal pathway while simultaneously inhibiting or exciting the sympathetic pathway.Conclusions:Intra-arterial injection of lidocaine during endovascular procedures can be recommended as an effective prophylactic approach for use in the treatment of the cerebrovascular disorder where there is high risk of embolization-induced TCR.

Augmented Reality Fluorescence Imaging in Cerebrovascular Surgery: A Single-Center Experience with Thirty-Nine Cases

Several intraoperative imaging methods exist in cerebrovascular surgery to visualize and analyze the vascular anatomy flow. A new method based on multispectral fluorescence (MFL) imaging of indocyanine green (ICG) video angiography (VA) allows real-time, augmented reality (AR) visualization of blood flow superimposed on white-light microscopic images. We describe our single-center experience using MFL AR in cerebrovascular surgery. Case descriptions are provided of cerebrovascular surgery with intraoperative use of MFL AR images performed at our institution from June 2018 to April 2020. MFL superimposes the blood flow in real time on white-light microscopic images. We used MFL AR imaging as well as standard ICG-VA visualization and intraoperative digital subtraction angiography (DSA) as a control. A total of 39 cases (33 aneurysm clippings, 4 arteriovenous malformations, and 2 external carotid-internal carotid bypass surgeries), were performed using MFL technology-based AR visualization of ICG. MFL AR imaging and DSA showed a high correlation concerning aneurysm occlusion and vessel patency. In arteriovenous malformation resection surgery, MFL AR imaging facilitated early identification of the feeding arteries and draining veins. Because of increased sensitivity of MFL AR, a reduced dose of ICG could be used, allowing repeated intraoperative imaging. There were no postoperative complications, side effects, or technical problems related to the use of MFL AR imaging. MFL AR is an easy-to-use adjunct in cerebrovascular surgery and shows a high correlation with intraoperative DSA. No interruption of the surgery is necessary because MFL AR images of the blood flow are superimposed in real time on white-light microscopic images.