Definition:
the urethro-vaginal fistula is an abnormal communication between the urethra and the vagina with an epithelium-coated pathway.
Etiology:
it can be secondary:
- to obstetric traumas (in which generally more complex fistulas develop);
- to incidental or vascular iatrogenic lesions during gynecological, abdominal or vaginal surgery, and urological surgery;
- at fractures of the pelvis;
- a radiotherapy (this situation generally develops 6-12 months after the termination of the radiation therapy, but can also arise years later);
- to neoplasm of the urethra or genitals.
It can also be observed during tuberculosis.
Exceptionally it is congenital.
Symptoms:
the common symptom is urinary incontinence, for which we must distinguish a form of stress and a “urinary urgency”. Small urine leakage may occur from the vagina resulting in leucorrhea, vaginitis and colpite.
Diagnosis:
it is necessary to highlight or exclude other concomitant causes of urinary incontinence. A vaginal inspection is performed to identify the fistula and any vaginal atrophy that must be treated before the surgery with estrogen administration. A staining test can be performed by instilling in the bladder, through a catheter, a dyeing substance and a vaginal swab in order to observe its coloration. In the case of urethro-vaginal fistula, the outermost part of the swab will be colored.
Confirmation of the diagnosis is generally obtained with urethrocystoscopy; the exam is essential to evaluate the involvement of the bladder neck and the trine.
Urinary cystourethrography with an upright patient may be useful in identifying the urethral defect, excluding the vesico-vaginal fistula and demonstrating a possible loss of contrast medium through the bladder neck.
A urodynamic evaluation can be used in selected cases for the evaluation of the sphincter function.
Therapy:
if small, a urethro-vaginal fistula can also close spontaneously if there is a sufficient urinary derivation (a suprapubic catheterization is preferable). In other cases the therapy is surgical and can be performed under peripheral or general anesthesia. The preferable access is that by vaginal route, certainly burdened by low operating stress, even if abdominal or combined abdominal-vaginal operations have been described.
The intervention, for the closure of the urethral breach, consists in the removal of a strip of vaginal mucosa from the anterior surface that is put back on the orifice of the pathway and sutured. The intervention is followed by the positioning of a suprapubic catheter to guarantee a valid urinary derivation, of a urethral catheter and of a vaginal swab soaked in an antibiotic solution.
Intraoperative complications:
they are negligible; vaginal bleeding is possible.
Postoperative complications:
the most common problems that appear after urethroplasty, especially if an anti-incontinence procedure has been associated, are urinary retention or abundant post-urination residue.
Excessive resection of the vaginal wall may result in vaginal stenosis or a reduction in vaginal length with the appearance of dyspareunia (in any case it is advisable to abstain from sexual intercourse for about three months after surgery).
Complications:
Relapses are possible.