[Clinical evaluation of micturitional dysfunction after the operation for rectal cancer and effects of mecobalamin on...

Examination including residual urine measurement, cystometry and urethral pressure profile was performed before and 8 weeks, 3 months and 6 months after the operation in 17 patients with rectal cancer who were divided into mecobalamin administered group (8 patients) and non-administered group (9 patients) at random. Administration of mecobalamin (500 gamma i.m., 3 times a week for 4 weeks) was started within 3 weeks after the operation. In the 17 patients, the rate of patients with residual urine over 51 ml was 65% at 8 weeks, 24% at 3 months and 24% at 6 months. The mean value of bladder pressure at maximum capacity after the operation in the 17 patients showed a significant increase compared to that before the operation, while the mean value of maximum urethral pressure after the operation showed a significant decrease compared to that before the operation. The bladder pressure in patients with residual urine less than 50 ml was significantly lower than that in patients with residual urine over than 5 ml. The bladder pressure in patients with residual urine reduced to less than 50 ml at 3 months showed a tendency to decline. The rate of patients with residual urine of less than 50 ml at 8 weeks was 50% in the mecobalamin administered group and 22% in the non-administered group. There was no significant difference in bladder pressure between the two groups, or before and after the administration of mecobalamin.