121. Urinary Tract Fistulae **PART 3** скачать в хорошем качестве

121. Urinary Tract Fistulae **PART 3**

Martius flap: For VVF in the mid-to-distal vagina, the labia are a useful source of well-vascularized tissue. The Martius flap was first described in 1928 and consists of fibrofatty tissue supplied by the internal pudendal artery inferiorly and the external pudendal artery superiorly, as well as with lateral connections derived from the obturator artery . The superior and inferior pedicles lend to the versatility of this flap, as it can be harvested in one of two directions to access the trigone, bladder neck, or urethra, as needed. Step 1 Labial Incision After the closure of the first two layers of the VVF, but before advancing the final vaginal epithelial flap, the Martius flap is har- vested. Before incision, the labium can be marked and injected with local anesthetic mixed with epinephrine for added he- mostasis. The labium is incised vertically, usually ,4–7 cm in length. The borders of the dissection are the labiocrural fold laterally, the bulbocavernosus muscle and labium minora medially, and the Colles fascia overlying the urogenital diaphragm posteriorly. Step 2 Dissection of the Fat Pad The yellow fibrofatty tissue is grasped with a Babcock or Allis clamp and can be maneuvered to aid with dissection along the medial and lateral aspects of the fat pad. There are natural surgical planes that are relatively hemostatic, and dis- section within this areolar layer in an anteroposterior direction can be performed with a combination of blunt and sharp dissection, and hemostasis with cautery. Care should be taken to remain lateral to the bulbocavernosus and ischiocav- ernosus muscles. The posterior aspect of the pad is freed from the underlying tissue by dissecting down to the adduc- tors on the lateral aspect and then coming underneath the pad either bluntly or with a clamp, which can be moved in parallel with the pad. Step 3 Creating the Flap Depending on the location of the fistula in question (e.g., rectovaginal or VVF), the superior or inferior blood supply can be maintained, whereas the opposite is ligated to allow rotation of the flap to the desired point of fixation. With VVF, the superior blood supply is often maintained, whereas the inferior aspect is ligated and separated to enable far- ther reach to the anterior vagina. This is accomplished by clamping the most posterior aspect of the fibrofatty graft and suture, ligating both ends to ensure hemostasis. At this point, the flap is freed from its inferior attachment and is supplied entirely by the superior blood supply (labial vessels from the external pudendal artery). Typically, a graft of 8–15 cm is achievable. Step 4 Tunneling the Graft A clamp and fingers are then used to create a tunnel approximately 2 cm wide under the epithelium between the flap dissec- tion and the fistula repair so that the flap can be rotated and fed through this tunnel to lie over the VVF closure. This is done by feeding a clamp from the vaginal side of the tunnel back to the labia and feeding the fibrofatty pad back through the tunnel with the clamp. Step 5 Fixing the Graft in Place The flap is positioned over the layered closure, and reinforcing sutures fix the flap into place, often in three to four places with 2-0 or 3-0 absorbable interrupted sutures. The flap should lie in place in a tension-free manner. The vaginal epithelium, which is the final layer of closure, is subsequently advanced over the tissue as previously outlined and closed in a running fashion, covering all layers of the VVF repair. Step 6 Labial Closure The bed of the labial dissection is inspected, and hemostasis achieved with cautery. The incision is closed in a layered fashion to minimize dead space. The epithelium is reapproximated with monofilament absorbable suture and/or skin glue. Most will leave a Penrose drain in place for 48 hours to minimize hematoma formation. A pressure bandage is placed to minimize hematoma formation, which can be removed with the drain.