Define the fistula by blue dye test if not done prior to OR. It is imperative to confirm that there is only a single tract and that it is well visualized.

Dilate the tract and place a Foley catheter into the tract. This is accomplished using small curved male sounds. Although the tissues of the apex often have limited mobility due to scarring, the Foley catheter can provide some useful traction, especially during the initial dissection (Fig. 17.1b).

Inject vasoconstrictor (epinephrine or vasopressin) around the fistula and make a circumscribing incision (Fig. 17.2).

From the initial circumscribing incision extend an inverted T incision to the lateral side walls and anteriorly as far as needed to achieve good mobilization. Many other authors suggest creating a distal U flap and a proximal inverted U flap. While this works well for the typical simple fistula the author has found it to be cumbersome for larger and more complex fistulae. The secret of adequate mobilization is the lateral dissection; this is emphasized and facilitated by the inverted T incision.

Dissect the proximal flap back to the apex of the vagina (Fig. 17.3)

Dissect the two anterolateral flaps to achieve a minimum 2 cm radius around the tract (Fig. 17.4). The dissection must extend far enough so that the fistula tract can be closed with absolutely no tension. If there is any question, extend the dissection!

Evaluate the edges of the fistula. If there is excessive scar tissue it should be trimmed. There is no evidence, however, that complete excision of the tract back to fresh tissue improves outcome; the author strongly counsels against this approach which tends to increase the size of the fistula and the blood loss. On the contrary, the epithelialization of the edges provides a strong site for suture placement and decreases pull-through.

Close the fistula with a single layer of full-thickness, interrupted absorbable sutures (3–0 Vicryl or similar), 4–5 mm back from the edge and 5 mm apart. Start with the stitches at each end of the repair taking care to ascertain ideal placement with secure placement including bladder mucosa (Fig. 17.5a, b). The closure is typically transverse but should be oriented in the direction of minimal tension.

Repeat the blue dye test after this first layer of suture. The repair should be watertight to 200–250 cc. If not, add additional suture or take the repair down and redo. When the first layer is watertight there is rarely a failure. If the first layer is not watertight there is a high rate of recurrence regardless of catheter drainage, additional layers, or tissue interposition.