The vasohibin (VASH) family consists of two genes, VASH1 and VASH2. VASH1 is mainly expressed in vascular endothelial cells and suppresses angiogenesis in an autocrine manner, whereas VASH2 is mainly expressed in cancer cells and exhibits pro‐angiogenic activity. Employing adenomatous polyposis coli gene mutant mice, we recently reported on the role of Vash2 in the spontaneous formation of intestinal tumors. In this study, we used K19‐Wnt1/C2mE (Gan) mice and examined the role of Vash2 in spontaneous gastric cancer formation. Gan mice spontaneously develop gastric tumors by activation of Wnt and prostaglandin E2 signaling pathways in gastric mucosa after 30 weeks of age. Expression of Vash2 mRNA was significantly increased in gastric tumor tissues compared with normal stomach tissues. When Gan mice were crossed with the Vash2‐deficient (Vash2 LacZ/LacZ) strain, gastric cancer formation was significantly suppressed in Vash2 LacZ/LacZ Gan mice. Normal composition of gastric mucosa was partially maintained in Vash2 LacZ/LacZ Gan mice. Knockout of Vash2 caused minimal reduction of tumor angiogenesis but a significant decrease in cancer‐associated fibroblasts (CAF) in tumor stroma. DNA microarray analysis and real‐time RT‐PCR showed that mRNA levels of epiregulin (Ereg) and interleukin‐11 (Il11) were significantly downregulated in gastric tumors of Vash2 LacZ/LacZ Gan mice. Furthermore, conditioned medium of gastric cancer cells stimulated migration of and α‐smooth muscle actin expression in fibroblasts, whereas conditioned medium of VASH2 knockdown cells attenuated these effects in vitro. These results suggest that VASH2 plays an important role in gastric tumor progression via the accumulation of CAF accompanying upregulation of EREG and IL‐11 expression.

We have developed a new educational approach to microsurgery in which a trainee and supervisor can cooperate with “4 hands” using the exoscope. We evaluated 4-hands surgery for intracranial hemorrhage (ICH) using the exoscope to validate the educational value and ergonomic advantages of this method. Thirty consecutive patients who underwent surgery for ICH using the exoscope between December 2018 and May 2020 were studied retrospectively. All operations were performed by a team comprising a supervisor (assistant) and a trainee (main operator). The assistant set the visual axis of the exoscope, and adjusted focus and magnification as a scopist. After setting the ORBEYE, the supervisor helped retract the brain and withdraw and irrigate the hematoma using suction tubes or brain retractors. Moreover, the trainee evacuated the hematoma with a suction tube and coagulated using bipolar forceps. Patient background and results of treatment were evaluated. Intraoperative postures of the operators were observed, and schemas compared with the use of a conventional microscope were developed. All microsurgical procedures were accomplished by a trainee with a supervisor using only the exoscope. During the surgery, the surgeons could work in a comfortable posture, and the supervisor and trainee could cooperate in microsurgical procedures using their four hands. The results of the present case series concerning evacuation of ICH were not inferior to those described in previous reports. To increase opportunities for education in microsurgery, 4-hands surgery for ICH using the exoscope appears feasible and safe and offered excellent educational value and ergonomic advantages.

Background and Study Aims Various minimally invasive approaches are used in neurosurgery. Surgeons must perform nondynamic fine movements in a narrow corridor, so specially designed surgical devices are essential. Unsophisticated instruments may pose potential hazards. The purpose of this study was to assess the factors associated with muscle fatigue during minimally invasive neurosurgery and to investigate whether physical stress can be reduced by refining the devices used. Material and Methods Four physical aspects of a handpiece were investigated: torque of conduits (0.20, 0.28, and 0.37 kgf*cm), shape of hand grip (five types), angle of the nozzle (0, 20, and 40 degrees), and weight balance (neutral, proximal, and distal). To evaluate muscle fatigue, surface electromyography was recorded from the extensor carpi radialis muscle and flexor carpi radialis muscle during a geometric tracing task. The maximum voluntary contraction (MVC) of each muscle and %MVC (muscle contraction during a task/MVC × 100) were used as the indexes of muscle fatigue. Results The shape of the hand grip significantly reduced %MVC, which is associated with muscle fatigue. The torque of conduits and angle of the nozzle tended to reduce muscle fatigue but not significantly. Weight balance did not affect muscle fatigue. Based on these results, we made two refined models: model α (torque of conduits 0.2 kgf*cm, angle of nozzle 20 degrees, neutral balance, hand grip with a 2.9 × 2.0-cm oval section with angled finger rest), and model β (torque of conduits 0.2 kgf*cm, angle of nozzle 20 degrees, neutral balance, hand grip with a 2.9-cm round section with a curved finger rest). The %MVC was significantly decreased with both types (p < 0.05 and p < 0.01, respectively), indicating reduction of muscle fatigue. Conclusions The geometrically refined surgical device can improve muscle load during surgery and reduce the surgeon's physical stress, thus minimizing the risk of complications.

Background: The midline suboccipital approach with the patient in the prone position is safe and effective for clipping vertebral artery–posterior inferior cerebellar artery (VA–PICA) aneurysms. Using a conventional surgical microscope from the rostral end of the patient for this approach without an extreme head-down position requires the surgeon to overhang the visual axis of the microscope and perform surgical manipulations in an uncomfortable posture. We report performing the midline suboccipital approach from the rostral end with slight head-down position using ORBEYE, a new high-definition (4K) three-dimensional exoscope. Case Description: A 65-year-old woman was admitted for clipping of a right unruptured VA–PICA aneurysm (maximum diameter, 5mm) located medially and ventral to the hypoglossal canal. After induction of general anesthesia, the patient was placed in the prone position with the head titled slightly downward. A midline suboccipital approach was performed from the rostral end of the patient using ORBEYE. Clipping was safely accomplished in a comfortable posture. No operative complications occurred. Postoperative computed tomography angiography showed complete aneurysmal obstruction. Conclusion: Exoscopic surgery using ORBEYE is feasible for a midline suboccipital approach to VA–PICA aneurysms from the rostral end of the patient with the patient in the prone with slight head-down position.

Yamamoto New Scalp Acupuncture (YNSA) has been used in clinical practice for pain symptoms worldwide. However, the safety of YNSA and the role of the diagnosis and stimulation points have never been investigated. This study aimed to investigate the safety of YNSA and the relationship between the diagnosis points, the stimulation points, and changes in shoulder stiffness. YNSA was performed at the shoulder point A, acupuncture at the non-shoulder point D, and no intervention as a control in 15 healthy participants three times with a washout period of 1 week. Adverse reactions (changes in blood pressure, changes in heart rate, or bleeding), objective evaluation of the pressure pain threshold (PPT) and muscle hardness (MH) scores at the shoulder, and subjective evaluation of shoulder stiffness with a visual analog scale (VAS) were recorded before, during, and 20 min after stimulation. In the safety evaluation, no adverse reactions such as hypotension, bradycardia, or bleeding/hematoma were observed. PPT and MH revealed no significant difference between the conditions. There was a significant difference in the VAS between all three conditions (p = 0.039). Post-hoc analysis showed a significant difference between controls and D-point stimulation (p = 0.034), but no significant difference between A- and D-point stimulation. VAS subanalysis and post-hoc analysis in right-LI4-positive subjects (n = 4) showed a significant difference in VAS between A-point stimulation and controls (p = 0.01, 0.015, respectively). Our pilot investigation exhibited the safety of YNSA. Diagnosis and stimulation points may relate to changes in shoulder stiffness; however, further comparative studies with YNSA are required.