Hypothesis / aims of study
Female urinary continence has a multitude of contributing factors. The pathophysiology behind the continence mechanism in females is far from unraveled. Female urethral surgeries like bladder neck resection (BNR) and urethroplasty carry a risk of incontinence, precluding their active utilization in clinical practice. We present our experience of two significant complications associated with female urethroplasty and their successful management. We have also tried to demonstrate that the risk of incontinence should not hinder the surgeon from offering surgical management for the underlying female urethral pathology.
Study design, materials and methods
Case one: Total urinary incontinence post female urethroplasty in post-radiation urethral stricture
A 55-year-old lady known case of carcinoma cervix(IIIb) post chemoradiotherapy underwent buccal mucosal graft dorsal onlay urethroplasty for radiation-induced female urethral stricture disease two years back. She presented with a history of urine leak on sneezing and coughing for one year, which progressed to continuous urinary incontinence. On examination, there was a narrow and fibrosed vagina with dry, atrophic periurethral tissue. Urinary incontinence was demonstrated on the stress test. She was treated on conservative measures initially for six months, but her symptoms worsened in the next six months. Her Medical, Epidemiologic, and Social Aspects of Aging (MESA) score was 26 for stress (question 1-9), and her Urogenital Distress Inventory (UDI-6) score was 62.5. Q-tip test was positive suggestive of stress urinary incontinence. On video-urodynamic study (VUDS), she demonstrated multiple stress leak (the first leak came at around 60 ml filling) and abdominal leak point pressure (ALPP) less than 50 cm of H2O with insignificant postvoid residual (PVR). Urethroscopy showed a patulous bladder neck. She was planned for an autologous pubovaginal sling. During surgery, lateral pockets were developed to the level of the bladder neck. An 8X2 cm rectus sheath sling was harvested and placed at the level of the bladder neck with both ends tied in a tension-free manner and taken out through two incisions made two cm lateral to pubic symphysis. She had a smooth postoperative course. The per urethral catheter was removed after one week. She voided normally with no episode of incontinence with voided volume (VV) 170 ml, maximum urinary flow (Qmax) of 31.5 ml/sec with negligible PVR on uroflowmetry. She remained dry after more than one year of follow-up. (Image 1)
Case two: Primary bladder neck obstruction misdiagnosed as female urethral stricture disease post vaginal graft urethroplasty managed successfully with bladder neck resection
34 years old female patient presented with straining to void, incomplete emptying and poor flow. She was managed with regular urethral dilatation and clean intermittent catheterization (CIC) outside with mild improvement. The local examination was unremarkable. Uroflowmetry showed plateau shaped curve with voided volume of 180 ml, Qmax 7.8 ml/sec with PVR of 200 ml. VUDS study was suggestive of bladder outlet obstruction(BOO). Bladder neck funneling was poor, with constriction was seen at the level of the proximal urethra. A streak of contrast was seen coming till the proximal urethra. On urethroscopy, dense fibrous whitish ring was encountered at the level of proximal to the mid urethra. A diagnosis of female urethral stricture disease was made because of urethroscopy findings, and the patient was subjected to dorsal onlay vaginal graft urethroplasty. However, her Qmax was 9 ml/sec in the immediate post-operative period, which was decreased gradually. She continued to have voiding lower urinary tract symptoms (LUTS) after the removal of the catheter with high PVR. She was subsequently managed with CIC for one more year. A repeat VUDS study showed bladder outlet obstruction with no funneling of the bladder neck. Finally, a diagnosis of primary bladder neck obstruction (PBNO) was made, and she underwent bladder neck resection (BNR). During surgery, circumferential resection was done between 5 and 7 O'clock position from the bladder neck to the end of the proximal urethra, and a good channel was created. Postoperatively Trial without catheter (TWOC) was successful after one week of surgery with Qmax of 22 ml/sec, voided volume of 360 ml, and negligible PVR on uroflowmetry. She is now voiding with good flow after six months of follow-up. (Image 2)
Interpretation of results
Besides the Hammock and Integral theories, new evidence like active reflex urethral closing mechanism has emerged recently to understand the pathophysiology of female urinary continence (1). The factors behind continence have both extrinsic and intrinsic components like contraction of the periurethral striated pelvic muscles, the tone of the smooth muscles at the bladder neck, the length of the female urethra, the centripetal force by both rhabdosphincter and lissosphincter, the hormone-sensitive cushioning vascular channel in the submucosa and the transference of intra-abdominal pressure, especially in moments of stress (2). Besides these, age, body mass index, parity, ethnicity, and comorbidities like diabetes, smoking, previous surgery, malignancy, and radiation are the other contributing factors.
In the first case, the outcome of urethroplasty was successful as the patient was voiding well for one year with good flow without the need for additional dilatation. However, her incontinence became bothersome to the extent of total incontinence. The possible reasons are the proximal location of the stricture with long urethrotomy during urethroplasty along with post-radiation changes in carcinoma cervix, which led to the poor periurethral supporting tissue and poor vascularity due to fibrosis along with a narrow atrophic vagina. Initially, conservative management was tried but failed. Poor quality of tissue bed and restricted mobility of the urethra led us to take autologous fascia as pubovaginal sling as the rescue measure in this case (3). The patient ultimately had a satisfactory outcome with the good urinary flow without any leak. So, in a case of post-radiation urethral stricture where the chance of stress incontinence is more due to multiple factors, we should not shy away from giving surgical management in the form of urethroplasty as an anti-incontinence procedure can be performed subsequently for a satisfactory end result.
Inadvertent dilatation for BOO in women can lead to anatomical and functional changes that can create a diagnostic dilemma. In the second case, although initial VUDS was suggestive of the possibility of PBNO, but the history of regular dilation and urethroscopy led us in the wrong direction of urethral stricture disease. The unrestored urinary flow in the post-operative period of urethroplasty questioned the diagnosis. There was a possibility that part of the sphincter might have been damaged while performing the dorsal onlay vaginal graft urethroplasty. Yet, BNR came to the rescue without any further complications like incontinence. Contrary to the first case, young age, healthy periurethral supporting tissue, and adequate waiting time for sphincter healing might have provided the continence mechanism.