Background: Carotid endarterectomy (CEA) is widely performed under operative microscopes. They provide magnified and stereoscopic vision of operative field suitable for precise maneuver. However, the microscope has some shortcomings, which are a narrow field-of-view, shallow depth-of-field, and the operator's fatigue due to fixed gaze posture through eyepieces. To overcome them, we introduced ORBEYE™ Surgical Microscope, which was 4K ultra high-definition three-dimensional (3D) system. We present our initial experience of the system for CEA and discuss its usefulness compared with the operating microscopes. Methods: A 66-year-old male presented to our department for the treatment of the left internal carotid artery severe stenosis. He underwent CEA using the ORBEYE™ Surgical Microscope. Results: The surgery was successfully completed only under the system without complication. The microscope was set over the operative field. Its wide field-of-view, deep depth of field, and smooth digital zooming allowed minimal repositioning of the microscope. The system provided high quality stereoscopic image of the surgical site, which enables us to perform precise surgery. The 55-inch 4K 3D monitor remarkably contributed to a reduction of the surgeons' fatigue. Conclusions: The ORBEYE™ Surgical Microscope, incorporating 4K 3D video technology, has overcome shortcomings of the operative microscope. This system is highly feasible for CEA and has the certain possibility for other neurovascular surgeries.

Objective: To clarify the safety and efficacy of pre-operative embolization using Onyx liquid embolic agent (Onyx; ev3) compared with N-butyl cyanoacrylate (NBCA; Cordis Neurovascular, Inc.) or coils in cerebral arteriovenous malformation (AVM) surgery.Methods: This was a retrospective review of a prospectively collected clinical database of brain AVMs treated at our institute from January 2005 to March 2021. A total of 38 consecutive patients who underwent AVM resection after pre-operative embolization were included. Based on pre-operative embolization materials, the patients were divided into the pre-Onyx group (n = 16), in which NBCA or coils were used for embolization, and the Onyx group (n = 22). Patient characteristics and treatment results were compared between the two groups.Results: Patient characteristics were comparable between the two groups in terms of age, sex, and rupture status. While the Spetzler–Martin grade was also similar between the two groups, the location of the AVM nidus in the eloquent area was slightly higher in patients in the Onyx group (72.7%) than in patients in the pre-Onyx group (43.8%) (P = 0.09). The embolization rate was higher in the pre-Onyx group (mean: 63.0%; range: 12.7–100%) than in the Onyx group (mean: 50.0%; range: 15.8–100%), but the difference was not statistically significant (P = 0.06). The time needed for surgical removal was shorter in the Onyx group (mean: 354.8 min; range: 144–884 min) than in the pre-Onyx group (mean: 457.9 min; range: 240–1,294 min); however, this difference was not statistically significant (P = 0.13). The amount of intraoperative bleeding was significantly lower in the Onyx group (mean: 129.8 ml; range: 20–540 mL) than in the pre-Onyx group (mean: 448.8 mL; range: 120–1,550 ml) (P = 0.0008). The surgical complication rates were comparable between the two groups (pre-Onyx group, 18.8%; Onyx group, 4.5%; P = 0.29).Conclusions: Pre-operative embolization with Onyx can significantly reduce the amount of intraoperative bleeding in AVM resection and may contribute to safe AVM surgery.

OBJECTIVE: Aneurysm rebleeding is a major cause of death and morbidity in patients with aneurysmal subarachnoid hemorrhage (SAH). Recognizing the predictors of rebleeding might help to identify patients who will benefit from acute management. This study was performed to investigate the predictors of aneurysm rebleeding and their impact on clinical outcomes in the preoperative, intraoperative, and postoperative periods.METHODS: The incidence of rebleeding, demographic data, and clinical data from 4933 patients with aneurysmal SAH beginning in the year 2000 were retrospectively analyzed in the Nagasaki SAH Registry Study. The authors performed multiple logistic regression analyses to identify the risk factors contributing to rebleeding and outcome after SAH.RESULTS: Preoperative rebleeding occurred in 7.2% of patients. Patient age (p = 0.01), multiple aneurysms (p < 0.01), aneurysm size (p < 0.0001), and heart disease (p = 0.03) were significantly associated with preoperative rebleeding. Conversely, intraoperative rebleeding occurred in 11.2% of patients. Aneurysm location (anterior communicating artery [ACoA]), family history (p = 0.02), preoperative rebleeding (p < 0.01), and clipping/coiling (p < 0.0001) were significantly associated with intraoperative rebleeding. Interaction analysis showed that clipping significantly affected intraoperative rebleeding at the ACoA (OR 4.00; 95% CI 1.82–8.80; p < 0.001). Postoperative rebleeding occurred in 2.4% of patients. Coiling/clipping (p < 0.0001) and intraoperative rebleeding (p < 0.01) were significantly associated with postoperative rebleeding. Rebleeding in all time periods examined significantly contributed to the clinical outcome after SAH.CONCLUSIONS: Aneurysm rebleeding after SAH has specific characteristics in the preoperative, intraoperative, and postoperative periods, and all of these characteristics contribute to the clinical outcome. The ACoA has a higher risk of intraoperative rebleeding, and endovascular coiling could be a good candidate in terms of techniques for preventing intraoperative rebleeding, although complete aneurysm obliteration should be accomplished.