Defining the "Cutoff" on the Urethral Caliber in Diagnosing a Female Urethral Stricture

Introduction The rarity in detecting female urethral stricture (FUS) backed by the inconsistency regarding the cutoff on the caliber to direct any treatment for its increase poses a challenge to its existence. Therefore, the present study was conducted to determine the caliber of the urethra that clearly identifies a FUS. Materials and method In this prospective observational study conducted between November 2015 and July 2017, women with obstructive lower urinary tract symptoms (LUTS) and a history of relief on at least a single urethral dilatation were included if the American Urological Association (AUA) score was more than seven and the maximum flow rate (Qmax) was less than 20 mL/sec. Of the 71 women recruited, 10 women had recognizable external causes: caruncle (five), mucosal prolapse (three), and meatal stenosis (two). The remaining 61 underwent voiding cystourethrogram (VCUG) and urodynamics followed by urethrocystoscopy, if the findings suggested a stricture. A definitive diagnosis was sought in those without stricture disease. We categorized all patients as either having a "true" stricture or an alternate etiology. Categorical variables were presented in number and percentage (%) and continuous variables as mean ± standard deviation (SD). Results The mean dilatation ranged between one and six; the mean AUA score, ~17.82 ± 3.59; mean Qmax, ~10.21 ± 3.39 mL/sec; and the mean post-void residue (PVR), 106.65 ± 51 mL. A total of 29 patients were diagnosed to have stricture (dense = 17; flimsy = 12). None of the patients in this group had a urethral caliber of more than 14 French (Fr). Other etiologies were dysfunctional voiding (17), underactive bladder (seven), cystocele (four), and primary bladder neck obstruction (PBNO) (four). Conclusion Women with voiding LUTS should be screened for FUS only if the urethral caliber is ≤14 Fr.