Operative procedure

The rectus abdominis flap

The flap is dissected with the patient supine or in the lithotomy position. Skin islands may be designed in a wide variety of shapes and orientations as long as a significant portion of the skin and subcutaneous tissues are centered over the muscle. In most cases an elliptical skin island is oriented vertically over the muscle (Figure 2). For vaginal reconstruction, a more transversely oriented skin island may be designed above or below the level of the umbilicus, depending on the placement of ostomy sites. The skin islands should approximate the dimensions of the defect to be covered.

The skin incision is carried down to the level of the anterior rectus sheath; subcutaneous tissue and skin are then elevated off the sheath to allow an incision through the fascia to be made 1 cm from the lateral edge of the muscle (Figure 2). The dissection is then carried around the anterior and lateral surfaces of the muscle to the posterior surface. Care is taken to minimize injury to the tendinous intersections while mobilizing the muscle. The muscle can be divided above the level of the costal margin if needed. The muscle is then dissected away from the abdominal wall in a distal to proximal direction along the posterior rectus sheath towards the inferior epigastric pedicle. Several large intercostal perforators are ligated laterally and the deep inferior epigastric pedicle (artery and two venae comitantes) is then identified and dissected out of its origin from the iliac vessels (Figure 3). The insertion of the muscle into the pubic symphysis can be left intact or detached, depending on the arc of rotation that is required. For vaginal reconstruction the skin island can be tubed and shaped into a pouch. It is then sutured to the remaining vaginal cuff from above. If perineal coverage is necessary, the flap can be tunneled in the subcutaneous plane over the inguinal ligament into the perineum or groin as needed (Figure 4). The donor site is closed primarily by approximating the remaining 1 cm cuff of anterior rectus sheath to itself with a large, non-absorbable suture. If necessary, skin and subcutaneous tissue flaps can be mobilized to reapproximate the skin flaps in the abdominal donor site.

The gracilis flap

The patient is usually placed in the lithotomy position for resections in this area. The hips are flexed and abducted. The medial thigh is prepared circumferentially down to the knee allowing access to the medial group of muscles. Figure 5 shows the underlying anatomy

An elliptical skin island measuring up to 6 cm 3 20 cm is outlined over the proximal two-thirds of the muscle (Figure 6). The anterior border of the incision lies on a line drawn between the pubic tubercle and the semitendinosus tendon. A separate, small access incision may be made distally if needed to identify the muscle tendon.

The skin is incised anteriorly down to the medial group of muscles. The sartorius muscle is identified and retracted superiorly. The gracilis tendon can now be identified distally, usually through a separate short distal incision, and the tendinous insertion divided (Figure 7). The posterior incision is made down to the muscle, taking care not to undermine perforators from the muscle to the skin or to shear the cutaneous aspect of the flap off the muscle. The flap is then elevated from distal to proximal on the thigh. One or two large perforators to the muscle are ligated distally. The main pedicle is identified entering the proximal third of the gracilis muscle in the space between the adductor longus and adductor magnus muscles (Figure 8), approximately 8-10 cm below the pubic tubercle. Once the pedicle is identified and preserved, the proximal muscle can be dissected and, if necessary, the origin from the pubic symphysis may be divided. The entire myocutaneous flap can then be tunneled through the subcutaneous skin bridge into the vaginal defect (Figure 9) and exteriorized through the introitus (Figure 10). The bilateral flaps are sutured to each other in the midline (Figure 11). The neovagina is shaped into a pouch by approximating the anterior, posterior, and distal skin edges of the flaps (Figure 12); this can then be inserted into the pelvic space that is left after the exenteration. The proximal end of the neovagina is sutured to the introitus (Figure 13).

Fasciocutaneous neurovascular pudendal thigh flaps

The fasciocutaneous flap is based on the posterior labial arteries, which are a continuation of the perineal artery. The posterior aspect of this flap is innervated by the posterior labial branches of the pudendal nerve and the perineal branches of the posterior cutaneous nerve of the thigh.

The patient is placed in the lithotomy position. A flap 3-6 cm wide and 10-15 cm long can be designed within the medial groin crease just lateral to the labia majora and the defect. Bilateral flaps can be designed for total vaginal reconstruction. The perineal defect is partially closed anteriorly and posteriorly leaving an entrance of suitable size into which the neovagina will be inserted (Figure 14).

The skin and subcutaneous tissues are incised as well as the deep fascia overlying the muscles of the medial thigh compartment as they insert onto the pubis and ischium (Figure 15). The flap is then elevated from distal to proximal in the subfascial plane over the adductor muscles in order to avoid injury to the neurovascular pedicle (Figure 16). The large distal branches of the perineal and pudendal vessels are identified and preserved. Often the dissection is carried into the fat of the ischiorectal fossa in order to achieve adequate rotation and mobilization of the flap. The flap can then be rotated into the defect. The donor site is closed primarily in layers. A neovaginal pouch can be reconstructed by suturing the lateral margins of bilateral flaps to each other (Figure 17); the neovagina is then transposed into the rectovesical space and the proximal ends sutured into the new vaginal introitus.

Virginal Introitus

Rectus abdominis myocutaneous flap elevated. Note the inferior epigastric pedicle entering the caudal aspect of the flap

Figure 3

Rectus abdominis myocutaneous flap elevated. Note the inferior epigastric pedicle entering the caudal aspect of the flap

The bulbocavernosus flap

The procedure is performed with the patient in the lithotomy position. An elliptical skin island, usually oriented vertically, is created over either labium majus (Figure 18). The skin incision over the labium majus is carried down to the bulbocavernosus muscle in the anterior vulva. Skin, subcutaneous tissue, and muscle are then mobilized on a posterior vulvar pedicle (Figure 19). A tunnel is created from the vaginal wall to the base of the myocutaneous flap and the flap is pulled through the tunnel to the fistula site (Figure 20). The skin edges of the flap are sutured to the vaginal mucosa with the muscle of the pedicle projecting into the bladder or rectum, where it will develop an epithelial lining. The labial incision is then closed (Figure 21).

Full-thickness cutaneous advancement flaps

Cutaneous advancement flaps (V-Y procedure, Z-plasty) are useful to close wounds under tension, where mobilization of adjacent skin and subcutaneous tissue can reduce skin tension and allow adequate skin approximation.

The procedure is performed with the patient in the lithotomy position. Skin islands of varying sizes and shapes can be created adjacent to the defect as long as the patient has a good microvasculature (Figure 22). The skin and subcutaneous tissue are mobilized from the underlying fascia of the transverse perineal muscle

Deep Transverse Perineal Muscle
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Figure 4

The anterior rectus fascia is approximated

(Figure 23). The size of the pedicle graft is tailored to the size of the defect. The pedicle flap is undermined and in a Z-plasty is rotated through 90° to fill the defect (Figure 24). Once the flap is rotated, the remaining skin edges are united (Figure 25). In a V-Y procedure the initial wedge (Figure 26) is advanced to fill the gap and then closed as a Y (Figure 27). Prolene 4- 0 sutures should be used for these closures.

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