Preoperative Preparation and Planning
Diagnosis of urethrovaginal fistula is based on a complete evaluation, including a thorough history, and a full physical examination, including a speculum examination. Cystourethroscopy can be useful to identify fistula location in most cases, and the use of a specialized urethroscope for female patients can be helpful because its shorter beak can better distend the female urethra for optimal visualization. Voiding cystography and an upper tract study are necessary to rule out concomitant vesicovaginal or ureterovaginal fistulas. Associated tests, including a tampon test or double-dye test, can be useful. In patients who also describe stress urinary incontinence, urodynamics can be helpful. It should also be emphasized that if a concomitant sling is considered at the time of fistula, no synthetic material should be used.
The timing of fistula repair is controversial, but tissues should be free of infection, inflammation, and induration. Principles of fistula repair include adequate tissue mobilization and fistula visualization, the use of sharp dissection, and removal of foreign bodies (e.g., a synthetic sling) in their entirety if present. Successful fistula closure is maximized by the use of healthy tissue flaps, multilayer and tension-free closure, consideration of tissue interposition, and adequate postoperative urinary drainage. The fistula tract itself is not excised but rather incorporated into the first layer of closure to prevent creation of a larger defect. That said, care should be taken to debride any tissue edges of marginal quality before closure. The initial attempt to perform fistula repair provides the best opportunity for a durable outcome. Involvement of the bladder neck or proximal urethra represents a further challenge and may require bladder neck reconstruction or concomitant or staged bladder neck sling.
Patient Positioning and Operative Technique
The patient is positioned in the dorsal lithotomy position. Prepare the lower abdomen, perineum, and vagina. Insert a 12-Fr suprapubic punch tube (SPT) via cystostomy under direct visualization and plug it. Perform cystourethroscopy using a female urethroscope to identify the fistula location. If the fistula is difficult to visualize, the fistula tract may be cannulated using a wire or ureteral catheter. An angle-tipped wire can be helpful of the angle of the fistula tract is challenging. Insert a 16-Fr urethral catheter. Obtain exposure using a Lone Star retractor (Cooper Surgical, Stafford, TX) and weighted speculum ( Fig. 84.1 ). In the rare instance of compromised exposure resulting from a narrow introitus, a posterolateral vaginal relaxing incision can be used to enhance visualization ( Fig. 84.2 ).
A circumscribing incision is made around the fistula opening. An inverted U -shaped incision is made in the anterior vaginal wall, extending up to and in continuity with the proximal aspect of the circumscribing incision ( Fig. 84.3 ). Using Metzenbaum scissors, the U -shaped flap is taken down above the glistening surface of the periurethral fascia layer, and the vaginal epithelium is undermined circumferentially around the fistula in a similar fashion ( Fig. 84.4 ). If any tenuous tissue is noted at the edge of the fistula, it is excised; the fistula tract itself is not excised but is closed in a transverse, tension-free fashion using a running 4-0 absorbable suture (Vicryl or Monocryl preferred) ( Fig. 84.5, A ). The repair is tested by injecting saline alongside the Foley catheter using an 18-gauge angiocatheter, and any residual defect is repaired with additional suture. A second reinforcing layer is performed by approximating the periurethral fascia in a vertical fashion using interrupted Lembert stitches of 4-0 absorbable suture ( Fig. 84.5, B ). Consideration of perforation of the endopelvic fascia may be considered to facilitate mobilization of the tissues and decrease tension. If closure of the fistula cannot be performed in a tension-free fashion, the periurethral fascia must be carefully mobilized as a separate layer and then approximated over the initial closure. At this point, a labial fat pad is used as tissue interposition (Martius flap) if desired (see later).