It has been reported that Choto-san (diao teng san) is effective for the treatment of patients suffering from hypertension. Narrowing of the retinal arterioles is one of the important findings in hypertension.
The authors examined the pharmacological effects of Choto-san on the blood pressure and narrowing of the retinal arterioles in spontaneously hypertensive rats (SHR) and strokeprone SHR (SHRSP).
SHR and SHRSP rats (nine treatment cases and five control cases) were used. 200mg/kg/day of Choto-san was administered orally to the SHR and SHRSP for 12 weeks. After the 12 weeks of administration, the blood pressure was measured by the tailcuff method. Narrowing of the retinal arterioles was measured by the percentage ratio of the artery to vein caliber.
After three months of administration of Choto-san, the blood pressure of the SHR and SHRSP was shown to be significantly lower than that of the control. The percentage ratio of the artery to vein caliber in the treatment group was shown to be significantly higher than that of the control group SHR and SHRSP.
These findings suggest that Choto-san may lower the blood pressure and inhibit narrowing of the retinal arterioles in SHR and SHRSP.

Recently, with the increase of laparoscopic surgery, there has also been an increase in the number of surgeries that require the head-down position for a long duration and left-right rotation. We have encountered 3 cases of brachial plexus neuropathy that was thought to be caused by such surgical positions in our institute. Currently, we have improved the fixation method and fixtures and created a neuropathy checklist, and we are conducting standardized observation and decompression programs within the team. We examined whether our current programs are effective using a body pressure measuring device for 20 patients undergoing headdown lithotripsy surgery under general anesthesia. The correlation between the mean body pressure on the right shoulder after 30 min and body tilt angle was studied. We also observed changes in body pressure before and after manual decompression every 30 min while the patient was in the head-down position. Before that study, we conducted an experience questionnaire survey of 10 operating room nurses. The results indicated that there was no increase in body pressure in proportion to the body tilt angle (15-20 deg). The body pressure after decompression decreased significantly at 30, 60, and 120 min after placing the patient in the head-down lithotripsy position. There was no significant correlation between body pressure and the headdown positioning time. There was a significant correlation between body mass index (BMI) and body pressure at 30 min (r=0.474, p=0.035). Complaints of trunk displacement, shoulder pain and pressure, and head and neck traction were often noted in the nurse questionnaire. These complaints were more frequently seen in cases with a larger right-down rotation angle and higher BMI. From these results, it was concluded that decompression of the body with the current fixtures and our regular observation and decompression program using the neuropathy checklist is effective for preventing brachial plexus injury in patients undergoing lithotripsy laparoscopic surgery in the head-down position and with left-right rotation.