Calibre of the External Urethral Meatus in Indian Population: A Cross-sectional Study

Abstract

Introduction: Transurethral resection instruments are designed as per western standards and are often found to be larger for Indian patients, leading to urethral trauma during instrumentation or higher incidence of urethral strictures postoperatively. Aim: To assess and record the calibre of the External Urethral Meatus (EUM) among Indian male and female population. Materials and Methods: This cross-sectional study was done at a tertiary health care centre over a period of one and half years from July 2016 to December 2017. All male and female patients above the age of 12 years undergoing lower urinary tract instrumentation at the institute underwent assessment for EUM calibre. A total of 1,127 males and 182 females were enrolled in the study. Descriptive statistics (mean, Standard Deviation, and range) were performed for age, height and the EUM in males and females. Linear regression analysis was used to analyse the correlation between EUM calibre and age; and EUM calibre and body height. The correlation was considered statistically significant when p<0.05. Results: The mean EUM calibre of the male population was observed to be 23.23±1.60 Fr and that of the female population was 23.58±2.00 Fr. On linear regression analysis, a significant but weak correlation was found between EUM calibre and body height in male (R2 value: 0.024, p-value<0.0001). On the other hand, no correlation was observed between EUM calibre and body height in females (R2 value: 0.009, p-value= 0.196). Conclusion: The average calibre of the EUM in Indian males was 23.23 Fr which is about 3 Fr smaller than the standard transurethral resectoscope sheath. Thus, use of larger sized sheaths may result in urethral stricture in narrow calibre urethra.