Next-Generation Exoscopic Surgery Featuring a Head-Mounted 3-Dimensional Display for Carotid Endarterectomy: 2-Dimensional Operative Video.

Recent advancements in medical equipment have led to the use of exoscopes in neurosurgery, thereby replacing conventional operating microscopes.1,2 These devices enable surgeons to work comfortably, even in situations requiring a tilted visual axis, and their effectiveness in carotid endarterectomy (CEA) for carotid artery stenosis has been reported.3,4 However, the placement of 3-dimensional (3D) monitoring devices is challenging.3,4 To address this issue, we present a case in which CEA was performed using ORBEYE with a 3D head-mounted display. This device allows continuous 3D observation of the surgical field on the preocular screen. Case: A 79-year-old man who had undergone chemoradiotherapy for left maxillary cancer 5 years earlier was referred to our department to undergo treatment for left internal carotid artery stenosis. Computed tomography angiography revealed severe left internal carotid artery stenosis with hypoechoic vulnerable plaques on carotid ultrasound. Carotid artery stenting was considered to be a better option than CEA. However, CEA yields better outcomes, especially in patients with vulnerable soft plaques.5 Left CEA was performed using ORBEYE with a 3D head-mounted display (HOGY Medical Co., Ltd.). The procedure was successfully performed under the observation of the head-mounted display, from skin incision to closure. Postoperatively, the patient had no neurological deficits but experienced transient hoarseness. Using an exoscope under the guidance of a head-mounted display represents a next-generation surgical technique that overcomes the limitations of traditional exoscopic surgery. The patient consented to the procedure, and the participants and any identifiable individuals consented to publication of his/her image. Our institutional review board approved this publication (#B230184).

Acute morphological changes of impending rupture of vertebral artery dissection: clinical management of symptomatic but unruptured vertebral artery dissection. Illustrative case.

BACKGROUND: The reported actual risk of rupture for vertebral artery dissection (VAD) in patients presenting with headache is very low, ranging from 0.4% to 1.0%. The authors report a case in which the dissection site dilated rapidly within several hours after the dissection occurred resulting in subarachnoid hemorrhage (SAH). OBSERVATIONS: A 49-year-old healthy man who had participated in a marathon noticed a headache while running. Magnetic resonance imaging (MRI) performed 2 days later revealed no findings suspicious for right VAD, but a string sign was observed in the left side, suggesting left VAD. Three hours following MRI, he developed severe headaches and became unconscious at home, prompting emergency services to rush him to the hospital. A computed tomography scan showed diffuse SAH and a rapidly enlarged aneurysmal dilatation in the right vertebral artery. He underwent endovascular internal trapping to prevent rebleeding. He was discharged without any neurological symptoms. No recurrence or new dissection occurred after 2 years of follow-up. LESSONS: Even in the absence of typical imaging findings, strict management, such as blood pressure control, is required when clinical findings strongly suggest VAD, and differentiation of VAD from primary headache is important. https://thejns.org/doi/10.3171/CASE24202.

Stereotactic radiotherapy of radiation-induced meningioma previously irradiated retrobulbar for Graves' ophthalmopathy: A case report.

A 69-year-old woman was diagnosed with an asymptomatic intracranial tumor nine years ago and has been followed with annual MR imaging studies. Two years ago, the tumor had grown in size, requiring treatment. She experienced ophthalmopathy due to hyperthyroidism 27 years ago and was treated with 20 Gy in 10 fractions using parallel opposed beams to her bilateral posterior eyeballs, supplemented with steroid pulse therapy. The tumor originated in the medial aspect of the right sphenoid border and compressed the temporal lobe, while bone infiltration was observed, partially extending to the soft tissue outside the maxillary sinus. The tumor was removed by craniotomy. The pathological diagnosis was atypical meningioma (WHO grade II). Four months postsurgery, the resection cavity's tumor exhibited growth inclination, necessitating Gamma Knife radiosurgery. Radiation planning was executed at a marginal tumor dose of 30 Gy in 5 fractions. Since the optic nerve had been previously exposed to radiation, a plan was devised to minimize radiation exposure. The dose on the optic nerve was limited to 6.9 Gy in 5 fractions. She did not experience any visual or visual field disruptions postradiation. This is a case of radiation-induced meningioma resulting from radiation therapy for Graves' ophthalmopathy and is the first reported case of a grade II meningioma. The patient's condition calls for adjuvant radiation therapy following surgical removal. Accordingly, a radiation treatment plan that safeguards the optic nerve, which was previously exposed to radiation, was deemed indispensable.

A vertebrobasilar junction aneurysm successfully treated with a combination of surgical clipping and flow diverter placement based on the results of computational fluid dynamics analysis: illustrative case.

BACKGROUND: The treatment of vertebrobasilar junction (VBJ) aneurysms is challenging. Although flow diverters (FDs) are a possible treatment option, geometrical conditions hinder intervention. VBJ aneurysms possess dual inflow vessels from the bilateral vertebral arteries (VAs), one of which is ideally occluded prior to FD treatment. However, it remains unclear which VA should be occluded. OBSERVATIONS: A 75-year-old male with a growing VBJ complex aneurysm exhibiting invagination toward the brainstem and causing perifocal edema required intervention. Preoperative computational fluid dynamics (CFD) analysis demonstrated that left VA occlusion would result in more stagnant flow and less impingement of flow than right VA occlusion. According to the simulated strategy, surgical clipping of the left VA just proximal to the aneurysm was performed, followed by FD placement from the basilar artery trunk to the right VA. The patient demonstrated tolerance of the VA occlusion, and follow-up computed tomography angiography at 18 months after FD treatment confirmed the disappearance of the aneurysm. LESSONS: Preoperative flow dynamics simulations using CFD analysis can reveal an optimal treatment strategy involving a hybrid surgery that combines FD placement and direct surgical occlusion for a VBJ complex aneurysm.

Expression of EGFR and p16 in Squamous Cell Carcinoma of External Auditory Canal.

The expression of EGFR and p16 in the external auditory canal squamous cell carcinoma (EACSCC) and their impacts on oncological outcomes were not well studied. Seventeen-one consecutive patients who were treated for EACSCC at Kobe University Hospital from 1995 to 2018 were enrolled in this study. The expression of EGFR, and p16 were evaluated and their impacts on oncological outcomes were statistically analyzed. Positive expression of EGFR was observed in 62 patients (87%). Strong positive expression of p16 were observed in 18 patients (32.4%), and weakly positive expression in 30 patients (42.3%), respectively. While the number of the patients with negative EGFR expression were limited, all the surgically treated patients with negative EGFR expression have been alive without disease. In the patients with T3 & T4a EACSCC, prognosis of the patients with positive p16 expression EACSCC tended to be better than those with negative p16 expression. These results suggest the clinical significance of EGFR and p16 expressions in the patients with advanced EACSCC to predict oncological outcomes.

Predicting impaired cerebrovascular reactivity and risk of hyperperfusion syndrome in carotid artery stenosis using BeamSAT magnetic resonance imaging.

Pencil-beam presaturation (BeamSAT) magnetic resonance imaging (MRI) produces selective magnetic resonance angiography (MRA) images of specific arteries, including the unilateral internal carotid artery (ICA-selective MRA) or vertebral artery (VA-selective MRA). We evaluate the influence of flow pattern, visualized using BeamSAT MRI, on preoperative cerebral hemodynamic status and postoperative hyperperfusion syndrome (HPS). Patients undergoing carotid artery stenting or carotid endarterectomy were categorized into two groups to evaluate flow pattern. Patients with neither crossflow on BeamSAT MRI nor mismatch in middle cerebral artery (MCA) signal intensity between ICA-selective and conventional MRA were classified into Group I, comprising 29 patients. Group II included all other patients comprising 19 patients, who were suspected of experiencing changes in intracranial flow patterns. Cerebral blood flow and cerebrovascular reactivity (CVR) were assessed using single-photon emission computed tomography, and potential HPS symptoms were retrospectively assessed by chart review. Preoperative ipsilateral CVR was significantly lower in Group II than in Group I (18.0% ± 20.0% vs. 48.3% ± 19.5%; P < 0.0001). Group II showed significantly impaired CVR (odds ratio 17.7, 95% confidence interval 1.82-171; P = 0.013) in multivariate analysis. The partial areas under the curve of the BeamSAT logistic model (0.843) were significantly larger than those of the conventional logistic model (0.626) over the range of high sensitivity (0.6-1) (P = 0.04). The incidence of postoperative HPS symptoms was significantly higher in Group II than in Group I (8/19 vs. 1/29; P = 0.001). BeamSAT MRI may be a valuable and non-invasive tool for assessing cerebral hemodynamics and predicting postoperative HPS.

A Case of Olfactory Neuroblastoma Developing Bilateral Retropharyngeal Lymph Node Metastasis 14-years After Skull Base Surgery.

Olfactory neuroblastoma (ONB) is an uncommon malignant tumor and is usually treated by a multidisciplinary approach includes surgery, radiotherapy, and chemotherapy. A 62 years-old male had a tumor in the nasal cavity and diagnosed as ONB with Kadish A stage. Anterior skull base surgery was performed as radical treatment. Since the surgical margin was negative, no postoperative radiotherapy was administered. 14 years after the surgery, bilateral otitis media with effusion (OME) was occurred, we found the recurrence tumor at bilateral retropharyngeal lymph node (RPLN) which surrounded the internal carotid arteries. Since these were unresectable, we planned chemoradiotherapy which was 70Gy of intensity modulated radiotherapy combined with two courses of carboplatin and etoposide. The tumor volume was reduced and bilateral OME were improved. He has been alive for 3 years after salvage treatment. Although ONB has a relatively good prognosis, it is known to often cause cervical lymph node metastasis. Grades III and IV of Hyams classification are considered high risk. This case, initial tumor was limited in the nasal cavity and its clinical classification was early stage, but Hyams classification was grade III. In reference to this case, considering that RPLN metastasis are difficult to radically resect at the salvage surgery, including this area in postoperative radiotherapy was considered an option.