Y-Stent Technique Using Dual Comaneci Embolization Assist Devices for Coil Embolization of a Ruptured Wide-Necked Anterior Communicating Artery Aneurysm: A Technical Case Report.

BACKGROUND AND IMPORTANCE: Despite technological advances, ruptured wide-necked aneurysms continue to pose a challenge for endovascular management. Comaneci (Rapid Medical) is a relatively new temporary aneurysm neck bridging device to assist in coiling of wide-necked aneurysms without the need for dual antiplatelet therapy or parent vessel flow interruption. Y configuration is often necessary to prevent coil migration in cases of wide-necked aneurysms. Thus far, there have been no reports of using Comaneci device in Y configuration to aid anterior circulation aneurysm treatment. CLINICAL PRESENTATION: A 60-year-old man presented with a Hunt-Hess grade 5, modified Fisher grade 4 subarachnoid hemorrhage from a ruptured wide-necked anterior communicating artery aneurysm with a dome-to-neck ratio of 1:2. Two Comaneci devices were used in a Y configuration to prevent coil prolapse into the contralateral A2 branch. After successful coiling of the aneurysm, both Comaneci devices were collapsed and removed without incident; the coil catheter was also removed without incident. Follow-up angiogram demonstrated successful occlusion of the wide-necked anterior communicating artery aneurysm without the use of a permanent stent or balloon assistance. CONCLUSION: This case represents a first-time report of successfully using 2 Comaneci devices in a Y configuration for the treatment of a ruptured wide-necked anterior circulation aneurysm. This knowledge can potentially further expand the use of double Comaneci devices in Y configuration for the treatment of both anterior and posterior circulation aneurysms.

Spontaneous development and involution of a de novo pseudoaneurysm at the superficial temporal artery-middle cerebral artery bypass anastomotic site in a patient with moyamoya disease: illustrative case.

BACKGROUND: De novo pseudoaneurysm formation is a rare complication of extracranial-intracranial bypass surgery. OBSERVATIONS: The authors report the case of a 28-year-old male who presented with new-onset right temporal and occipital ischemia who was found to have bilateral proximal internal carotid artery occlusion with collateral vasculature formation consistent with moyamoya disease. The patient underwent bilateral superficial temporal artery-middle cerebral artery bypasses. A de novo pseudoaneurysm was found at the left-sided bypass distal anastomotic site recipient vessel 1 month after the surgery. The pseudoaneurysm demonstrated a progressive reduction in size and eventual complete involution at 6 months after surgery. LESSONS: Limited literature reports extracranial-intracranial bypass-associated aneurysms treated primarily with either clipping or resection and reanastomosis. The authors demonstrate, for the first time, a progressively benign natural history course of an extracranial-intracranial bypass distal anastomotic site pseudoaneurysm.

Endovascular treatment of a ruptured pure arterial malformation and associated dysplastic middle cerebral artery dissecting aneurysm: illustrative case.

BACKGROUND: Pure arterial malformations are characterized as unique cerebrovascular lesions with a dilated, coil-like appearance and tortuous arteries without early venous drainage. Historically, these lesions have been described as incidental findings with a benign natural history. However, pure arterial malformations can rarely demonstrate radiographic progression and develop associated focal aneurysms with an unclear risk of rupture. Whether radiographic progression of these lesions or the presence of an associated aneurysm warrants treatment remains controversial. OBSERVATIONS: A 58-year-old male presented with sudden-onset left hemiparesis. Computed tomography revealed a large, acute, right frontotemporoparietal intraparenchymal hemorrhage with underlying irregular curvilinear calcifications. Diagnostic cerebral angiography revealed a dysplastic right middle cerebral artery dissecting aneurysm along the M2 segment associated with a pure arterial malformation, which was treated with endovascular flow diversion in a delayed fashion. LESSONS: Pure arterial malformations with associated focal aneurysms may not exhibit a benign natural history as once thought. Intervention should be considered for ruptured pure arterial malformations to mitigate the risk of rerupture. Asymptomatic patients with a pure arterial malformation with an associated aneurysm should at least be followed closely with interval radiographic imaging to evaluate for malformation progression or changes in aneurysmal morphology.

Conical drill bit for optimized external ventricular drain placement: a proof-of-concept study.

OBJECTIVE: Despite external ventricular drain (EVD) procedures being commonplace in neurosurgical practice, suboptimal placement rates remain high, and complications are not uncommon. The angle of the EVD catheter insertion and the accuracy of the drill hole placement are major factors determining successful EVD placement that are dependent on the drill bit morphology. The standard cylindrical 2-fluted twist drill bit creates a relatively deep and narrow drill hole that requires precise positioning, has limited visibility of the drill hole bottom and restricted catheter angular adjustment range, and poses the risk of inadvertent dural puncture. To overcome the standard problems associated with EVD drill bit morphology, the authors propose novel cone-shaped drill bits for EVD placement. METHODS: Conical drill bits of 30° and 45° were designed, manufactured, and tested in a simulated laboratory setting as well as in three human cadavers with intact skull, dura mater, and brain. Drill bit performance was rated by neurosurgical trainees across various domains using Likert scale-type questions. RESULTS: In the laboratory, maximum drilling temperatures adjacent to the drill hole were recorded and compared for the standard drill bit and the 30° and 45° conical drill bits and were not significantly different (p = 0.631 and p = 0.326, respectively). The maximum temperature recorded directly underneath the drilling site for the 45° drill bit was significantly higher than the temperature of the standard drill bit (p = 0.043). The differences between the standard and 30° drill bits were not significant (p = 0.783). Upon cadaver testing, the drilling times with 30° and 45° conical drill bits were significantly longer than those with the standard drill bit (p = 0.036 and p = 0.002, respectively). Likert scale scores were significantly higher for the conical 30° (median [IQR] 4.7 [3.3-5]) and 45° (4 [2-5]) drill bits than for the standard drill bit (1.7 [1-2.5], p < 0.0001), indicating significantly better performance. Conical drill bits used as a "rescue" strategy allowed for an EVD catheter angular adjustment range 6 to 9 times greater than that for the standard drill bit and resulted in a zero inadvertent dural puncture rate. CONCLUSIONS: The 30° conical drill bit can be safely used on its own or as a rescue tool to potentially achieve improved confidence, visualization, targeting, and precision of EVD placement while essentially eliminating the possibility of unintentional dural puncture with minimal increase in the total procedure time.

Primary intracranial extraosseous Ewing's sarcoma of the skull base in an elderly adult: illustrative case.

BACKGROUND: Primary extraosseous intracranial Ewing's sarcoma, also known as a peripheral primitive neuroectodermal tumor or "small round blue cell tumor," is an extremely rare entity with limited representation in the literature beyond the pediatric population. OBSERVATIONS: A 67-year-old male suffering occipital headache, nausea, and gait disturbance was found to have a large, avidly contrast-enhancing cerebellopontine angle mass extending into the cervical spinal canal with associated mass effect on medulla, cerebellum, fourth ventricle, and cervical spinal cord. This mass was not present on the imaging from 8 years prior. He underwent surgical debulking and pathology results demonstrated a malignant small round cell tumor showing diffuse immunopositivity for cytokeratins, CD99 and NKX2.2 with EWRS1-FLI1 rearrangement in 84% of the nuclei confirmatory of Ewing's sarcoma. After 14 cycles of chemotherapy and 6 weeks of radiotherapy, 22 months after discovery, the patient remains in clinical and radiographic remission with complete return to his baseline functioning. LESSONS: Primary skull base extraosseous Ewing's sarcoma should be considered in the differential diagnosis even in the elderly population when imaging studies demonstrate aggressive tumor growth patterns. Tumor debulking to establish a diagnosis followed by adjuvant chemoradiation therapy can result in clinical improvement with remission.

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

BACKGROUND: 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. OBJECTIVE: To present our institutional experience using DLCFA grafts for cerebral revascularization. METHODS: Retrospective review of perioperative data and outcomes for patients undergoing cerebrovascular bypass surgery using a DLCFA graft from 2016 to 2019. RESULTS: 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). CONCLUSION: 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.

Anomalous Frontal Extra-Axial Midline Traversing Vein as the Potential Source of Subarachnoid Hemorrhage.

Extra-axial developmental venous anomalies (DVAs) are important anatomic structures that contribute to supplemental venous drainage of intracranial contents into the extracranial veins. We present the case of a 35-year-old woman with a sudden-onset severe headache, nausea, and vomiting who was found to have an atraumatic subarachnoid hemorrhage of left frontal convexity. Workup revealed a large anomalous extra-axial vein originating in the right frontal area, traversing the left frontal region, penetrating the left frontal bone just above the supraorbital foramen with likely drainage into the left external jugular vein. This vein could not be classified as an emissary vein given the lack of direct communication with the superior sagittal sinus anterior portion, which was found to be hypoplastic. This case report adds to the literature a description of a previously unreported midline traversing frontal extra-axial vein directly draining frontal lobes with a potential implication in an atraumatic subarachnoid hemorrhage of frontal convexity.

Altered adult neurogenesis and gliogenesis in patients with mesial temporal lobe epilepsy.

The hippocampus is the most common seizure focus in people. In the hippocampus, aberrant neurogenesis plays a critical role in the initiation and progression of epilepsy in rodent models, but it is unknown whether this also holds true in humans. To address this question, we used immunofluorescence on control healthy hippocampus and surgical resections from mesial temporal lobe epilepsy (MTLE), plus neural stem-cell cultures and multi-electrode recordings of ex vivo hippocampal slices. We found that a longer duration of epilepsy is associated with a sharp decline in neuronal production and persistent numbers in astrogenesis. Further, immature neurons in MTLE are mostly inactive, and are not observed in cases with local epileptiform-like activity. However, immature astroglia are present in every MTLE case and their location and activity are dependent on epileptiform-like activity. Immature astroglia, rather than newborn neurons, therefore represent a potential target to continually modulate adult human neuronal hyperactivity.

"Craniotomy Within Craniotomy" Technique for Safe Resection of an Intracranial Arteriovenous Malformation With Frontal Bony Erosion: 2-Dimensional Operative Video.

Surgical resection is one option in the treatment of large high-grade brain arteriovenous malformations (AVMs). Resection of AVMs with skull-eroding components can be challenging due to the risk of excessive bleeding from these components during craniotomy and bone flap removal. We present a case of a 25-yr-old woman who presented with an acute onset right-sided frontal headache. She was found to have a large, frontal Spetzler-Martin grade IV AVM with an associated dural AVM. The AVM had caused focal erosions of the right frontal bone by a venous varix traversing the region of the calvarial defect. An elective staged endovascular embolization followed by surgical resection was recommended considering the patient's young age and the large size of the AVM located in a noneloquent area. Given the high risk of intraoperative hemorrhage during the craniotomy portion of the procedure, a "craniotomy within craniotomy" approach was planned. During this approach, a small rectangle of bone, including the portion eroded by the venous varix, was left in place, while the larger bone flap surrounding it was removed for an initial approach to the AVM. The small bony piece was safely removed at later stages of resection once the arterial feeders had been reasonably obliterated. Immediate postoperative catheter angiogram demonstrated good filling of the intracranial vascular territories with no residual AVM. The patient developed mild left facial and left hand weakness postoperatively, which resolved after 2 wk of follow-up. The patient remained neurologically intact on further follow-up.

Cerebrovascular bypass for ruptured aneurysms: A case series.

In patients with aneurysmal subarachnoid hemorrhage (aSAH) unfavorable for endovascular or traditional open surgical techniques, surgical revascularization strategies comprise one of remaining limited options. There is nonetheless a paucity of data on the safety and efficacy of bypass in aSAH. In this study, we aimed to investigate complications and outcomes in a cohort of patients with aSAH treated with bypass. A prospective single-surgeon database of consecutive patients treated for aSAH between 2013 and 2018 was retrospectively analyzed. Complications and functional status at discharge were recorded and analyzed for the patients that underwent bypass surgery. Forty patients with aSAH were treated with bypass surgery (23 extracranial-intracranial; 17 intracranial-intracranial). All-cause perioperative mortality was 13% (6 patients). At discharge and at mean 14-month follow up, respectively, 16/40 (40%) and 16/25 (64%) of patients achieved a Glasgow Outcome Score of 4-5. All-cause, in-hospital complications occurred in 28 patients (70%), of which any ischemic complication occurred in 20 patients (50%), 7 (18%) being open surgical complications. This work represents the largest modern series of bypass for aSAH to date. In cases of aSAH unfavorable for endovascular intervention or traditional open surgical techniques, bypass remains a viable option in this complex group of patients.

External Carotid Artery-to-Middle Cerebral Artery Bypass Using a Saphenous Vein Graft With 3-Vessel Anastomosis for the Treatment of a Large, Ruptured Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video.

Cerebral revascularization is the treatment of choice for select complex intracranial aneurysms unamenable to traditional approaches.1 Complex middle cerebral artery (MCA) bifurcation aneurysms can include the origins of 1 or both M2 branches and may benefit from a revascularization strategy.2,3 A novel 3-vessel anastomosis technique combining side-to-side and end-to-side anastomoses, allowing for bihemispheric anterior cerebral artery revascularization, was recently reported.4 This 2-dimensional operative video presents the case of a 73-yr-old woman who presented as a Hunt-Hess grade 4 subarachnoid hemorrhage due to the rupture of a large right MCA bifurcation aneurysm. The aneurysm incorporated the origins of the frontal and temporal M2 branches and was deemed unfavorable for endovascular treatment. A strategy using a high-flow bypass from the external carotid artery to the MCA with a saphenous vein (SV) graft was planned to revascularize both M2 branches simultaneously, followed by clip-trapping of the aneurysm. Intraoperatively, the back walls of both M2 segments distal to the aneurysm were connected with a standard running suture, and the SV graft was then attached to the side-to-side construct in an end-to-side fashion. Catheter angiograms on postoperative days 1 and 6 demonstrated sustained patency of the anastomosis and good filling through the bypass. The patient's clinical course was complicated by vasospasm-related right MCA territory strokes, resulting in left-sided weakness, which significantly improved upon 3-mo follow-up with no new ischemia. The patient consented for inclusion in a prospective Institutional Review Board (IRB)-approved database from which this IRB-approved retrospective report was created.

Comparative Assessment of Extracranial-to-Intracranial and Intracranial-to-Intracranial In Situ Bypass for Complex Intracranial Aneurysm Treatment Based on Rupture Status: A Case Series.

BACKGROUND: Comparative outcomes of extracranial-to-intracranial (EC-IC) and intracranial-to-intracranial (IC-IC) bypass for complex aneurysm treatment based on rupture status are not well described in the literature. In this study, we compare outcomes of EC-IC and IC-IC bypass for complex intracranial aneurysm treatment based on rupture status. METHODS: A prospective neurosurgical patient database was retrospectively reviewed. Sixty-three consecutive patients with aneurysm managed with revascularization were identified between July 2014 and December 2018. RESULTS: During the study period, 41 patients with aneurysm underwent EC-IC bypass (65%; 24 [58.5%] ruptured, 17 [41.5%] unruptured) and 22 patients with aneurysm underwent IC-IC bypass (34.9%; 13 [59.1%] ruptured, 9 [40.9%] unruptured). Graft spasm occurred in 4 patients (9.8%) in the EC-IC group (all ruptured aneurysms) and all anastomoses were patent on immediate postoperative imaging. Perioperative mortality occurred in 5 patients who underwent EC-IC bypass (12.2%; 3 ruptured, 2 unruptured) EC-IC and 2 patients who underwent IC-IC bypass (9.1%; both ruptured); (P = 0.709). Bypass-related complications occurred only in patients with ruptured aneurysm (2 [8.3%] in the EC-IC group and 0 [0%] in the IC-IC group; P = 0.285). For unruptured aneurysms, the overall complication rate was lower in IC-IC compared with the EC-IC group (P = 0.006). Modified Rankin Scale scores on discharge were significantly lower in IC-IC compared with EC-IC bypass for unruptured aneurysms (P = 0.008). There was a trend for shorter temporary occlusion and hospitalization times and overall better outcomes with IC-IC compared with EC-IC bypass. CONCLUSIONS: Although often considered riskier than EC-IC bypass, IC-IC in situ bypass showd a favorable technical and safety profile for the treatment of complex, unruptured aneurysms.

An Expedited Transition to the Back Wall Suturing for Side-to-Side In Situ Microvascular Anastomosis: A Technique Update.

BACKGROUND: The side-to-side in situ microvascular anastomosis is an important tool in the cerebrovascular neurosurgeon's armamentarium. The execution of the side-to-side anastomosis, however, can be limited by the inability to acquire sufficient visualization and approximation of the recipient and donor vessels. OBJECTIVE: To expedite the transition to the back wall suturing of the donor and recipient vessels during side-to-side in situ microvascular anastomosis. METHODS: Incorporation of the first suture throw from the outside to the inside of the vessel lumen with the initial stay suture at the proximal apex of the arteriotomy is described. The apical knot is tied between one limb of the resultant loop and the free end of the suture. The remainder of side-to-side anastomosis can then be completed in a standard fashion starting from the inside of the lumen. RESULTS: This modification allows for an expedited transition to the back wall suturing of the 2 arterial segments and avoids difficulties associated with taking the first bite from behind the knot at the proximal apex of the arteriotomy or the transfer of the needle between the approximated vessels. This updated technique is illustrated with a case example, illustration, and video. CONCLUSION: This technical modification for the side-to-side anastomosis helps optimize microsurgical efficiency by limiting needle, suture, and vessel handling after the initial suture placement, which has classically been a challenge of this bypass.

Intentional Subtotal Resection of Vestibular Schwannoma: A Reexamination.

Background Treatment of vestibular schwannomas (VS) remains controversial. Historical surgical series prioritized gross total resections (GTR); however, near total resections (NTR) and intentional subtotal resections (STR) aiming at improving cranial nerve outcomes are becoming more popular. Objective The main purpose of this article is to assess the tumor control and facial nerve outcomes in VS patients treated with STR or NTR. Methods VS patients undergoing STR or NTR at our institution between 1984 and 2016 were retrospectively reviewed. Patient demographics, extent of tumor resection, facial nerve injury, tumor recurrence, and need for Gamma Knife radiosurgery were analyzed. Facial nerve outcomes were quantified using House-Brackmann (HB) scores. Tumor regrowth was defined by the San Francisco criteria. Results Four-hundred fifty-seven VS resections were performed in a 32-year period. Sixty cases met inclusion criteria. The mean (range) follow-up duration was 30.9 (12-103) months. The STR cohort ( n = 33) demonstrated regrowth in 12 patients (36.3%) at an average of 23.6 months. The NTR cohort ( n = 27) did not experience tumor recurrence. Risk of tumor recurrence was positively correlated with preoperative tumor size ( p = 0.002), size of residual tumor ( p < 0.001), and STR ( p < 0.001). Facial nerve outcomes of HB1-2 were observed in the majority of patients in both cohorts (74.1% NTR, 56% STR), though NTR was associated with a higher likelihood of facial nerve recovery ( p = 0.003). Conclusion GTR remains the gold standard as long as facial nerve outcomes remain acceptable. NTR achieved superior tumor control and higher likelihood of facial nerve recovery compared with STR.

Discrepancy in Neurologic Outcomes Following Aneurysmal Subarachnoid Hemorrhage as a Function of Socioeconomic Class.

OBJECTIVE: To investigate potential health care discrepancies in patients with ruptured cerebral aneurysms undergoing microsurgical intervention. METHODS: We retrospectively reviewed patients with ruptured intracranial aneurysms treated at our tertiary referral university hospital (UH) and safety net county hospital (CH) from 2010 to 2015. We identified 73 UH patients and 58 CH patients. RESULTS: UH patients had shorter time duration between rupture and intervention (P < 0.001) and higher rates of intubation on admission (P = 0.01). Verapamil was more frequently used for clinical vasospasm in UH patients, at 0.13 (95% confidence interval [CI], 0.09-0.18) treatments per patient per day versus 0.077 (95% CI, 0.047-0.12) treatments per patient per day in CH patients, though there was no difference in delayed cerebral ischemia (P = 0.15). The majority of the CH cohort was uninsured (26.3%; UH 0%) or had Medicaid (59.7%; UH 35.2%) (P < 0.001). The UH had more dispositions to home or rehabilitation centers than the CH (82% vs. 67.3%; P = 0.04). After adjusting for disease severity, hospital stay, and insurance status, CH patients were 3.73 (95% CI, 1.25-12.14) times more likely to be discharged with a poor modified Rankin Scale score and 3.08 (95% CI, 1.04-9.61) times more likely to be discharged with a poor Glasgow Outcome Scale score compared with UH patients (P = 0.02 and P = 0.04, respectively). CONCLUSIONS: Limited resource availability in a safety net hospital system could be a major driving force behind the health care discrepancy identified in our ruptured cerebral aneurysm population. Reallocation of resources to supplement advanced inpatient acute care technologies and, more importantly, post-acute care environments can narrow the outcomes gap.

Bypass and Deconstructive Technique for Hunt and Hess Grade 3-5 Aneurysmal Subarachnoid Hemorrhage Deemed Unfavorable for Endovascular Treatment: Case Series of Outcomes and Comparison with Clipping.

BACKGROUND: Intracranial bypass to treat ruptured aneurysms has been well described in the literature but is largely deferred in patients with higher Hunt and Hess (H & H) grades due to complexity and length of surgery, risk of inducing vasospasm, and poor prognosis. However, there is a paucity of data and no direct comparison with more traditional open surgical techniques. This study investigated outcomes in patients with H & H grade 3-5 aneurysmal subarachnoid hemorrhage (aSAH) unfavorable for stand-alone endovascular treatment managed with bypass compared with direct surgical clipping. METHODS: A prospective database of patients treated for aSAH with H & H grade 3-5 between 2013 and 2018 was retrospectively analyzed. Complications and functional status at discharge and latest follow-up were compared between patients who underwent bypass surgery versus direct clipping. RESULTS: Twenty-three patients underwent revascularization, and 60 underwent clipping alone. There were no significant differences in all-cause 30-day mortality (15% vs. 16%; P = 0.97) or Glasgow Outcome Scale and modified Rankin Scale at discharge or median 8-month follow-up (P > 0.67). There was a higher overall stroke rate with revascularization (P = 0.004), specifically endovascular treatment-related stroke (P = 0.049), with no difference in surgical (P = 0.47) or vasospasm-related stroke (P = 0.53). There were no differences in overall complications, medical complications, seizures, reruptures, hydrocephalus, or perioperative death (P > 0.05). CONCLUSIONS: Bypass is a viable option for patients presenting with higher H & H grade aSAH deemed unfavorable for stand-alone endovascular therapy. Despite obvious differences in aneurysm complexity and a higher risk of stroke, functional outcomes with revascularization can be comparable with clipping in this high-risk patient cohort.

The Use of a Novel Perfusion-Based Human Cadaveric Model for Simulation of Dural Venous Sinus Injury and Repair.

BACKGROUND: Dural sinus injuries are potentially serious complications associated with acute blood loss. It is imperative that neurosurgery trainees are able to recognize and manage this challenging scenario. OBJECTIVE: To assess the feasibility of a novel perfusion-based cadaveric simulation model to provide the fundamentals of dural sinus repair to neurosurgical trainees. METHODS: A total of 10 perfusion-based human cadaveric models underwent superior sagittal sinus (SSS) laceration. Neurosurgery residents were instructed to achieve hemostasis by any method in the first trial and then repeated the trial after watching the instructional dural flap technique video. Trials were timed until hemostasis and control of the region of injury was achieved. Pre- and post-trial questionnaires were administered to assess trainee confidence levels. RESULTS: The high-flow extravasation of the perfusion-based cadaveric model mimicked similar conditions and challenges encountered during acute SSS injury. Mean ± standard deviation time to hemostasis was 341.3 ± 65 s in the first trial and 196.9 ± 41.8 s in the second trial (P < .0001). Mean trainee improvement time was 144.4 s (42.3%). Of the least-experienced trainees with longest repair times in the initial trial, a mean improvement time of 188.3 s (44.8%) was recorded. All participants reported increased confidence on post-trial questionnaires following the simulation (median pretrial confidence of 2 vs post-trial confidence of 4, P = .002). CONCLUSION: A perfusion-based human cadaveric model accurately simulates acute dural venous sinus injury, affording neurosurgical trainees the opportunity to hone management skills in a simulated and realistic environment.

Transblepharo-Preseptal Modified Orbitozygomatic Approach for Resection of Giant Frontal Cavernous Malformation: 3-Dimensional Operative Video.

A previously healthy 44-year-old woman presented with a first-time seizure. Magnetic resonance imaging (MRI) revealed a right frontal intraaxial mass extending from the orbitofrontal gyri and gyrus rectus to the head of the caudate (Video 1). The mass demonstrated heterogeneous signal intensity on precontrast T1-weighted MRI, minimal contrast enhancement, and mixed intensity on gradient echo MRI sequence consistent with a likely cavernous malformation. Given the location above the orbital roof with cranial-caudal extension to the level of the caudate, a transblepharo-preseptal modified orbitozygomatic craniotomy was recommended. With the assistance of plastic surgery, the lesion was approached through an eyelid incision that extended laterally to expose the keyhole. A McCarty burr hole was made, followed by a tailored orbitozygomatic craniotomy with osteotomies extending through the superolateral orbit and greater sphenoid wing to expose the proximal sylvian fissure. Dura was opened in a C-shaped fashion over the periorbital fat to allow for mild downward retraction of the globe, exposing the subfrontal trajectory. The opticocarotid cistern was opened to allow for cerebrospinal fluid egress and relaxation, and the lesion was readily identified through the use of stereotactic neuronavigation and presence of a faint hemosiderin blush within the underlying parenchyma. The standard microsurgical technique was used to perform a gross total resection of the pathologically confirmed cavernous malformation. The orbitozygomatic bone flap was replaced and plated, and the wound was closed in multiple layers. The patient was seen at a 3-month follow-up without further seizures.