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Background and Objectives: Neurosurgeons need a profound knowledge of the surgical anatomy of the cerebral arteries to safely treat patients. This is a challenge because of numerous branches, segments, and tortuosity of the main blood vessels that supply the brain. The objective of this study was to create high-quality three-dimensional (3D) anatomic photorealistic models based on dissections of the brain arterial anatomy and to incorporate this data into a virtual reality (VR) environment., Methods: Two formaldehyde-fixed heads were used. The vessels were injected with radiopaque material and colored silicone and latex. Before the dissections, the specimens were computed tomography scanned. Stratigraphical anatomic dissection of the neck and brain was performed to present the relevant vascular anatomy. A simplified surface scanning method using a mobile phone-based photogrammetry application was used, and the data were incorporated into a VR 3D modeling software for post-processing and presentation., Results: Fifteen detailed layered photorealistic and two computed tomography angiography-based 3D models were generated. The models allow manipulation in VR environment with sufficient photographic detail to present the structures of interest. Topographical relevant anatomic structures and landmarks were annotated and uploaded for web-viewing and in VR. Despite that the VR application is a dedicated 3D modeling platform, it provided all necessary tools to be suitable for self-VR study and multiplayer scenarios with several participants in one immersive environment., Conclusion: Cerebral vascular anatomy presented with photogrammetry surface scanning method allows sufficient detail to present individual vessel's course and even small perforating arteries in photorealistic 3D models. These features, including VR visualization, provide new teaching prospects. The whole study was done with simplified algorithms and free or open-source software platforms allowing creation of 3D databases especially useful in cases with limited body donor-based dissection training availability., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Background: The use of thrombectomy in patients with acute stroke and a large infarct of unrestricted size has not been well studied., Methods: We assigned, in a 1:1 ratio, patients with proximal cerebral vessel occlusion in the anterior circulation and a large infarct (as defined by an Alberta Stroke Program Early Computed Tomographic Score of ≤5; values range from 0 to 10) detected on magnetic resonance imaging or computed tomography within 6.5 hours after symptom onset to undergo endovascular thrombectomy and receive medical care (thrombectomy group) or to receive medical care alone (control group). The primary outcome was the score on the modified Rankin scale at 90 days (scores range from 0 to 6, with higher scores indicating greater disability). The primary safety outcome was death from any cause at 90 days, and an ancillary safety outcome was symptomatic intracerebral hemorrhage., Results: A total of 333 patients were assigned to either the thrombectomy group (166 patients) or the control group (167 patients); 9 were excluded from the analysis because of consent withdrawal or legal reasons. The trial was stopped early because results of similar trials favored thrombectomy. Approximately 35% of the patients received thrombolysis therapy. The median modified Rankin scale score at 90 days was 4 in the thrombectomy group and 6 in the control group (generalized odds ratio, 1.63; 95% confidence interval [CI], 1.29 to 2.06; P<0.001). Death from any cause at 90 days occurred in 36.1% of the patients in the thrombectomy group and in 55.5% of those in the control group (adjusted relative risk, 0.65; 95% CI, 0.50 to 0.84), and the percentage of patients with symptomatic intracerebral hemorrhage was 9.6% and 5.7%, respectively (adjusted relative risk, 1.73; 95% CI, 0.78 to 4.68). Eleven procedure-related complications occurred in the thrombectomy group., Conclusions: In patients with acute stroke and a large infarct of unrestricted size, thrombectomy plus medical care resulted in better functional outcomes and lower mortality than medical care alone but led to a higher incidence of symptomatic intracerebral hemorrhage. (Funded by Montpellier University Hospital; LASTE ClinicalTrials.gov number, NCT03811769.)., (Copyright © 2024 Massachusetts Medical Society.)

Background: The posterior cerebral arteries (PCAs) are terminal branches of the basilar artery (BA) and are responsible for the primary supply of the occipital lobe. Saccular aneurysm is most commonly seen close to the bifurcation of the BA. Various surgical interventions are performed for aneurysms. Therefore, the anatomy and localization of the BA and PCA are crucial. The aim of this study was to determine the characteristics of these arteries in a large Anatolian population., Methods: The study included 170 Anatolian fresh cadavers. The diameters of the BA and PCA were measured. Correlations according to sex and age groups were analyzed. The Q1, Q2, and Q3 angles between the right and left PCA, between the right PCA and BA, and between the left PCA and BA, respectively, were measured. The location of the PCA relative to the sulcus pontocruralis (pontocrural groove) was also evaluated., Results: The diameter of the artery increased with age and was higher in males than in females. Q1 and Q2 diameters were larger in males, while the Q3 diameter was larger in females. The Q1 angle between the right and left PCAs was found to be higher in age range 40-59 years with a mean of 87.33 ± 17.91 mm. Finally, the bifurcation point of the PCA was most frequently located above the sulcus pontocruralis (pontocrural groove) and least frequently located on the sulcus pontocruralis (pontocrural groove)., Conclusions: The findings of our study will contribute to the planning of surgical approaches, the development of endovascular devices, the success of invasive procedures, and the reduction of complications., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: The anatomical association between the lesion and the perforating arteries supplying the pyramidal tract in insulo-opercular glioma resection should be evaluated. This study reported a novel method combining the intra-arterial administration of contrast medium and ultrahigh-resolution computed tomography angiography (UHR-IA-CTA) for visualizing the lenticulostriate arteries (LSAs), long insular arteries (LIAs), and long medullary arteries (LMAs) that supply the pyramidal tract in two patients with insulo-opercular glioma., Methods: This method was performed by introducing a catheter to the cervical segment of the internal carotid artery. The infusion rate was set at 3 mL/s for 3 s, and the delay time from injection to scanning was determined based on the time-to-peak on angiography. On 2- and 20-mm-thick UHR-IA-CTA slab images and fusion with magnetic resonance images, the anatomical associations between the perforating arteries and the tumor and pyramidal tract were evaluated., Results: This novel method clearly showed the relationship between the perforators that supply the pyramidal tract and tumor. It showed that LIAs and LMAs were far from the lesion but that the proximal LSAs were involved in both cases. Based on these results, subtotal resection was achieved without complications caused by injury of perforators., Conclusion: UHR-IA-CTA can be used to visualize the LSAs, LIAs, and LMAs clearly and provide useful preoperative information for insulo-opercular glioma resection., (© 2023. The Author(s).)

Rationale: A persistent primitive trigeminal artery (PPTA) is a rare embryonic cerebrovascular anomaly. Hemifacial spasm (HFS) refers to involuntary contractions of facial muscles caused by the compression of blood vessels against the root exit zone of the facial nerve. There have been no reported cases of PPTA causing neurovascular contact and HFS. Microvascular decompression surgery effectively treats HFS, but operating on strong PPTA vessels poses challenges. We aim to introduce a more efficient approach for overcomes these difficulties and facilitates surgery., Patient Concerns: A 44-year-old male patient without any underlying medical conditions presented to our hospital with involuntary movements of the left side of his face accompanied by numbness in the left maxilla (V2 area)., Diagnosis: Brain magnetic resonance imaging and magnetic resonance angiography showed that PPTA was in contact with the left facial nerve., Interventions and Outcomes: Following a retro-sigmoid craniotomy, we attempted to interpose the facial nerve and the PPTA as an offender vessel, but the decompression was not sufficient. However, after transposing the vessel using the proximal Teflon transposition with interposition technique, the strength of the involuntary movements was reduced. Following surgery, there was no more lateral spreading response, and the patient symptoms improved., Lessions: In cases where the vessel causing HFS is particularly strong and thick, the proximal Teflon transposition with interposition technique for transposition may be advantageous. This method could simplify and enhance the efficacy of microvascular decompression, without compromising the quality of surgical outcomes., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: When treating intracranial aneurysms with open microsurgery, rare cases arise in which an ipsilateral approach leads to poor visualization, lack of proximal control, or potential damage to nearby vital structures due to the anatomy of the aneurysm., Case Description: We describe a patient with a small, unruptured aneurysm arising from the medial aspect of the distal supraclinoid internal carotid artery (ICA), just below the ICA bifurcation. A contralateral surgical approach was chosen because our view of the aneurysm from an ipsilateral approach would have been obstructed by the ICA. The contralateral approach provided excellent exposure of the aneurysm and allowed for precise clip placement without complications., Conclusions: Contralateral approaches may be a good option for some small medially pointing aneurysm of large proximal cerebral arteries.

Background: The basal ganglia, a group of subcortical nuclei located deep in the insular cortex, are responsible for many functions such as motor learning, emotion, and behavior control. Nowadays, because it has been shown that deep brain stimulation and insular tumor surgery can be performed by endovascular treatment, the importance of the vascular anatomy of the basal ganglia is being increasingly recognized., Objective: To explain the arterial blood supply of the basal ganglia using white matter dissection., Methods: The Klingler protocol was used to prepare 12 silicone-injected human hemispheres. The dissections were performed from lateral to medial with the fiber dissection technique to preserve arteries., Results: The globus pallidus blood supply came from the medial lenticulostriate, lateral lenticulostriate, and anterior choroidal arteries; the substantia nigra and subthalamic nucleus were supplied by the branches of posterior cerebral artery; the putamen was supplied by the lateral and medial lenticulostriate arteries; and the caudate nucleus was supplied by the lateral lenticulostriate and medial lenticulostriate arteries and the recurrent artery of Heubner., Conclusion: Knowledge of the detailed anatomy of the basal ganglia and its vascular supply is essential for avoiding postoperative ischemic complications in surgeries related to the insula. In addition, knowledge of this anatomy and vascular relationship opens the doors to endovascular deep brain stimulation treatment. This study provides a 3-dimensional understanding of the blood supply to the basal ganglia by examining it using the fiber dissection technique. Further studies could use advanced imaging modalities to explore the vascular relationships with critical structures in the brain., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Background: Intracranial aneurysms (IAs) are dilatations of the cerebral arteries, whose treatment is commonly based on the implant of a metallic clip on the aneurysm neck. Despite the dissection and understanding of the surgical anatomy of the IA when often only parts of it are visible, the choice of the ideal clip to be used is one of the surgical difficulties. Although current imaging tests guarantee IA visualization, currently there is no planning method that allows for a real three-dimensional (3D) visualization for optimal choice of clip prior to surgery. The aim of this study is to evaluate whether IA biomodels generated by additive manufacturing methods are useful for surgical clip selection in microsurgeries for IA., Methods: Three-dimensional (3D) IA biomodels of 10 patients with IA were evaluated using computerized tomography, surgical microscope, and 3D printer. The research was divided into 4 phases as follows: development of the 3D biomodels, evaluation of the biomodel dimensional characteristics, surgical planning evaluation with the biomodel and its clipping effectiveness, and evaluation of the actual surgical simulation process within the models., Results: Ten 3D biomodels were obtained, made of a malleable and hollow part, formed by the IA and related arteries, and another rigid part, mimicking the skull and other arteries of the skull base. Based on these 3D models, 10 clips were chosen during the surgical planning, and all exactly matched the clip characteristics used during the actual surgeries. The surgical simulation with the biomodels performed by 2 neurosurgeons still in training obtained 100% accuracy in the identification of the clips that were eventually used during the actual surgeries., Conclusions: 3D biomodels generated by additive manufacturing methods were effective for surgical clip selection in microsurgeries for IA, reducing surgical time, increasing cerebral angioarchitecture understanding, and providing more safety in this type of surgery., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: An anomalous subarcuate loop (SL) of the anteroinferior cerebellar artery (AICA) is a rare anatomic variation, which increases the complexity and risk of vestibular schwannoma (VS) removal. However, preoperative diagnosis of this anomaly remains difficult. The aim of this study was to report three types of anomalous SLs encountered during VS removal and to describe the "Deep Subarcuate Fossa (SF)" sign and its significance in the diagnosis and treatment of an osseous-penetrating SL., Methods: We prospectively observed 963 patients with newly/recently diagnosed VS who underwent surgical treatment performed by the senior author (P.Z.) from 2012 to 2021 and identified 16 patients with an anomalous SL. The SF was retrospectively measured on preoperative thin-slice temporal bone computed tomography in 963 patients., Results: Three types of anomalous SLs were encountered during VS removal: the apex of the SL was embedded in the dorsal tumor capsule (type I, 1 case), the dura (type II, 8 cases), or the dura and bone (type III, 7 cases) surrounding the SF. The depth of the SF in 7 patients with a type III anomalous SL ranged from 2.3 to 7.0 mm (3.56 ± 1.56 mm), which was significantly larger than that in 845 patients without an osseous-penetrating SL (1.23 ± 0.43 mm) (p = 0.008). When the depth of the SF exceeded 2 mm, the sensitivity and precision of the diagnosis of a type III anomalous SL were 100% (7/7) and 31.8% (7/22), respectively., Conclusion: Three types of anomalous SLs may be encountered during VS removal, and AICA displacement is recommended before tumor removal. The "Deep SF" sign may indicate the existence of a type III anomalous SL and it can predict the depth of the AICA in the bone and guide the drilling of the bone around the vessel loop., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: The preservation of the anterior choroidal artery (AChA) is essential for avoiding neurological sequelae after mesial temporal lobe epilepsy (mTLE) surgery. The purpose of this study is to reveal the anatomical variation in which the perforating branches arise from the plexal segment of the AChA by using a modern neuroimaging modality., Methods: This study analyzed 3D rotational angiography (3DRA) images from 56 subjects. The AChA and perforating branches were visualized using slab MIP. We analyzed branching patterns, courses of the perforating arteries arising from the plexal segment of the AChA, and the anastomosis of the AChA with other cerebral arteries., Results: The slab MIP applied to 3DRA visualized one or more perforating branches from the AChA in 92.9% of cases. The presence of perforating branches arising from the AChA plexal segment was 17.3%. Most of the branching points of plexal perforators were likely located in the operative field during hippocampal resection. The course of the AChA plexal perforators included the posterior limb of the internal capsule. Anastomosis with other cerebral arteries was visualized in 25% of the AChA with plexal perforators., Conclusions: 3DRA slab MIP was useful for visualizing the perforating branches of the AChA. Our results showed the possibility that surgical manipulation of the choroid plexus may cause infarction in the AChA territory. We suggest that the existence of the AChA plexal perforators should be recognized to further enhance the safety of hippocampal resection for mTLE., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: In surgeries involving resection of the amygdala, despite clear relations established with the medial, lateral, anterior, posterior, and inferior segments, the upper limit remains controversial. The optic tract (OT) has been anatomically considered as a good landmark immediately inferior to the striatopallidal region. This anatomic structure has barely been explored by microsurgical study, generating uncertainty about the exact relationship with the surrounding structures., Objective: To describe the OT in its entire length through microsurgical study, showing its superior, inferior, medial, and lateral relationships and highlighting its value as a landmark in superior amygdala resection., Methods: Microsurgical anatomic dissection of the OT, from its origin in the chiasm to the lateral geniculate nucleus was performed in 8 alcohol-fixed human hemispheres, showing its different segments and relations. Photographs were taken from different angles to facilitate surgical orientation., Results: We performed a dissection of the OT, showing its position relative to caudate and hippocampal formations. We exposed the structures related to the OT superiorly (striatopallidal region and superior caudate fasciculus), inferiorly (head of the hippocampus, amygdala, anterior choroidal artery, perforating artery branch of the anterior choroidal artery, terminal stria, and basal vein), medially (internal capsule and midbrain), and laterally (temporal stem [uncinate and inferior fronto-occipital fascicle], anterior perforated substance, and superior caudate fasciculus)., Conclusion: To date, there is a paucity of articles describing the anatomy of the OT from a neurosurgery perspective. In this study, we describe the microsurgical anatomic path of the OT, as a reliable upper limit landmark for amygdala resection., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Background and Purpose: Aspiration thrombectomy has become a preferred approach to recanalize large-vessel occlusion in stroke with a growing trend toward using larger-bore catheters and stronger vacuum pumps. However, the mechanical response of the delicate cerebral arteries to aspiration force has not been evaluated. Here, we provide preclinical and clinical evidence of intracranial arterial collapse in aspiration thrombectomy., Materials and Methods: We presented a clinical case of arterial collapse with previously implanted flow diverters. We then evaluated the effect of vacuum with conventional aspiration catheters (with and without stent retrievers) in a rabbit model ( n  = 3) using fluoroscopy and intravascular optical coherence tomography. Then, in a validated human cadaveric brain model, we conducted 168 tests of direct aspiration thrombectomy following an experimental design modifying the catheter inner diameter (0.064 inch, 0.068 inch, and 0.070 inch), cerebral perfusion pressures (mean around 60 and 90 mm Hg), and anterior-versus-posterior circulation. Arterial wall response was recorded and graded via direct transluminal observation., Results: Arterial collapse was observed in both the patient and preclinical experimental models. In the human brain model, arterial collapse was observed in 98% of cases in the M2 and in all the cases with complete proximal flow arrest. A larger bore size of the aspiration catheter, a lower cerebral perfusion pressure, and the posterior circulation in comparison with the anterior circulation were associated with a higher probability of arterial collapse., Conclusions: Arterial collapse does occur during aspiration thrombectomy and is more likely to happen with larger catheters, lower perfusion pressure, and smaller arteries., (© 2022 by American Journal of Neuroradiology.)

A persistent stapedial artery originates from the petrous segment of the internal carotid artery due to failure of the regression of the embryonic stapedial artery. During embryologic development, the stapedial artery supplies the middle meningeal artery through the ventral pharyngeal artery. The presence of a persistent stapedial artery can result in direct communication between the basilar and middle meningeal arteries. We present a cerebral angiogram image of an adult patient that shows a right-sided persistent stapedial artery with communication between the right middle meningeal and basilar arteries. It is important to recognize such rare anatomic variants during endovascular interventions to avoid catastrophic complications such as nontarget embolization of the posterior circulation., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: The most common cause of trigeminal neuralgia is neurovascular conflict, particularly arterial compression of the trigeminal nerve (ACTN). It is possible to show this condition preoperatively on fine-cut constructive interference in steady state magnetic resonance imaging (MRI), supplemented by time-of-flight magnetic resonance angiography. We have noticed significant variability in the interpretation of these studies between radiologists and the treating neurosurgeon. We have assessed the sensitivity and specificity of these 2 styles of interpretation compared with the intraoperative observations., Methods: We studied 68 patients who underwent de novo microvascular decompression from 2011 to 2018 under the care of a single neurosurgeon in Melbourne, Australia. Data was recorded prospectively in the radiology reports, operation reports, hospital admission records and neurosurgeon correspondence from the perioperative clinic reviews. In particular, the surgical interpretation of the MRI was clearly described prospectively and preoperatively in the correspondence. The presence or absence of ACTN was recorded prospectively in the operation report. These data were collated retrospectively by the first author., Results: Of patients, 83.8% (57/68) had clear ACTN confirmed at surgery. Radiologists detected this abnormality in 50.9% (29/57) of these patients, with a sensitivity of 50.9% and specificity of 81.8%. The operating neurosurgeon detected ACTN in 87.7% (50/57) of the positive cases with a sensitivity of 87.7% and a specificity of 72.7%. Statistical analysis showed a significant disagreement between both styles of interpretation, with a radiologic accuracy of 55.9% compared with 85.3% neurosurgically (P < 0.0001). Follow-up review of the patient's response to surgery further supported the neurosurgical diagnosis of ACTN., Conclusions: There was a strong tendency for radiologists to underreport ACTN on the preoperative MRI compared with the intraoperative findings. In this series, the neurosurgeon was able to accurately detect ACTN in 88% of patients preoperatively. However, the diagnosis of absent ACTN was still associated with a false-negative rate of 46.7% when the neurosurgeon performed the interpretation. At the current standard of fine-cut constructive interference in steady state MRI in Melbourne, underdetection of ACTN remains common. Clinicians using this test need to be acutely aware of its limitations in deciding whether to proceed to microvascular decompression., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: To present a retrospective review of a single-institute experience with bypass surgery of complex anterior cerebral artery aneurysm., Methods: Eight patients (5 females and 3 males; mean age, 34.2 years) with complex anterior cerebral artery aneurysms were treated with bypass. There were 3 precommunicating aneurysms, 1 communicating artery aneurysm, and 4 postcommunicating aneurysms (2 in A2 and 2 in A3). A3-A3 side-to-side in situ bypass was performed in 6 cases. A3-radial artery-A3 interpositional bypass was performed in 1 case with A3 segments located far apart, and A3-A3 transplantation was performed in 1 case with nonparallel aligned A3 segments. Of the 8 aneurysms, 3 were secured with proximal clipping, 1 was secured with distal clipping, 1 was secured with direct clipping, 1 was secured with isolation, and 2 were secured with embolization., Results: Aneurysm obliteration was achieved in all cases. Only 1 in situ bypass from a smaller donor artery to a larger recipient artery failed with minor postoperative infarction. Intraoperative bleeding from the site of anastomosis occurred in 1 case during embolization. All patients had complete recovery with normal neurological function during follow-up at outpatient clinics., Conclusions: We established a simplified surgical algorithm for complex anterior cerebral artery aneurysms based on the geometrical and spatial relationship between efferent arteries. The reasons for bypass failure and hemorrhagic complication were also discussed., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Surgical planning for treating brain arteriovenous malformations (bAVMs) is challenging because it entails visualizing 3-dimensional (3D) relationships between the nidus, its feeding and en passage arteries, and draining veins. Surgical experience in developing the capacity to mentally visualize pathological bAVM angioarchitecture could be complemented by this software, and thus potentially lower the steep learning curve for understanding complex bAVM angioarchitecture. We evaluated the clinical application of freely available online 3D reconstruction software in facilitating visualization of AVM angioarchitecture for presurgical planning., Methods: Preoperative Digital Imaging and Communications in Medicine magnetic resonance imaging/magnetic resonance angiography images of 56 superficial bAVMs from 2013 to 2018 were processed using open-source software Horos. 3D rendered images were compared with the surgical view to evaluate software accuracy and determine its value as a preoperative tool. 3D reconstructed images were compared with intraoperative recordings., Results: A useful image identifying both the main feeding artery and draining vein was achieved in 35 of 56 cases (62.5%). Reconstructions of small AVMs (nidus ≤2 cm) and those located within the temporal or cerebellar cortex were less useful due to soft tissue artifacts. Frontal and parietal lobe lesions had significantly higher rates of identifying feeding arteries and draining veins (P < 0.05)., Conclusion: Presurgical planning for resection of superficial bAVMs using Horos software allows for a comprehensive 3D analysis of the bAVM angioarchitecture. This technique is most useful for frontal and parietal lobe lesions, and aids the surgeon in formulating an optimal surgical strategy. The 3D reconstruction of the brain surface offers a surgical map not influenced by brain shift., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Fenestrations of cerebral arteries are congenital variants that develop when primitive vessels fuse incompletely. An association between the incidence of aneurysm and a fenestrated artery has been noted in the radiological literature. However, technical limitations of radiological studies may hamper visualization of small fenestrations and aneurysms. We sought to analyze a large, postmortem collection of human brains to assess the association between aneurysm formation and the presence of fenestrations., Methods: This study included 333 formalin-fixed brains. The arachnoid was dissected under a microscope, the cerebral arteries were completely exposed, and fenestrations and aneurysms were identified and measured. For each specimen, age, sex, and all vascular abnormalities and variations were recorded for analysis., Results: Fenestrations were present in 41% of the specimens, and 37% of these were multiple. Fenestrations were 3.1 ± 2.5 mm long and most commonly occurred in the anterior communicating artery (63%). Aneurysms were present in 8% of the specimens, usually in the anterior communicating artery or the middle cerebral artery. An aneurysm correlated with a fenestration was detected in 2% of all specimens (n = 4) and was not statistically significant (P = 0.18)., Conclusions: Fenestrations of the intracranial arteries are a common anatomical finding. They are present most often in the anterior communicating artery. Most aneurysms were detected in the anterior communicating artery and middle cerebral artery. We conclude that the existence of an aneurysm in a fenestrated artery is an incidental, rather than causal, relationship., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Aneurysm clipping simulation models are needed to provide tactile feedback of biological vessels in a nonhazardous but surgically relevant environment., Objective: To describe a novel system of simulation models for aneurysm clipping training and assess its validity., Methods: Craniotomy models were fabricated to mimic actual tissues and movement restrictions experienced during actual surgery. Turkey wing vessels were used to create aneurysm models with patient-specific geometry. Three simulation models (middle cerebral artery aneurysm clipping via a pterional approach, anterior cerebral artery aneurysm clipping via an interhemispheric approach, and basilar artery aneurysm clipping via an orbitozygomatic pretemporal approach) were subjected to face, content, and construct validity assessments by experienced neurosurgeons (n = 8) and neurosurgery trainees (n = 8)., Results: Most participants scored the model as replicating actual aneurysm clipping well and scored the difficulty of clipping as being comparable to that of real surgery, confirming face validity. Most participants responded that the model could improve clip-applier-handling skills when working with patients, which confirms content validity. Experienced neurosurgeons performed significantly better than trainees on all 3 models based on subjective (P = .003) and objective (P < .01) ratings and on time to complete the task (P = .04), which confirms construct validity. Simulations were used to discuss clip application strategies and compare them to prototype clinical cases., Conclusion: This novel aneurysm clipping model can be used safely outside the wet laboratory; it has high face, content, and construct validity; and it can be an effective training tool for microneurosurgery training during aneurysm surgery courses., (© Congress of Neurological Surgeons 2021.)

Background: Endoscopic endonasal surgery has proved to offer a practical route to treat suprasellar lesions, including tumors and vascular pathologies. Understanding the different configurations of the anterior cerebral communicating artery (ACoA) complex (ACoA-C) is crucial to properly navigate the suprachiasmatic space and decrease any vascular injury while approaching this region through an endonasal approach., Methods: An endoscopic endonasal transplanum-transtubercular approach was performed on 36 cadaveric heads (72 sides). The variations of the ACoA-C and feasibility of reaching its different components were analyzed. The surgical area exposure of the lamina terminalis was also quantified before and after mobilization of the ACoA-C., Results: The typical ACoA-C configuration was found in 41.6% of specimens. The following 2 main variations were identified: accessory anterior cerebral artery segment 2 (5, 13.9%) and common trunk of anterior cerebral artery with absence of ACoA (5, 13.9%). Of 101 recurrent arteries of Heubner, 96 (95.0%) were identified within 4 mm proximal or distal to the ACoA. The mean lamina terminalis exposure area was 33.1 ± 16.7 mm 2 , which increased to 59.9 ± 11.9 mm 2 after elevating the ACoA., Conclusions: A considerable amount of variation of the ACoA-C can be found through an endoscopic endonasal transplanum-transtubercular approach. These configurations determine the feasibility of lamina terminalis exposure and the complexity of reaching the ACoA. Assessment of ACoA morphology and its adjacent structures is crucial while approaching the suprachiasmatic through a transnasal corridor., (Copyright © 2021. Published by Elsevier Inc.)