Genitourinary and Perineal Reconstruction

Deep Inferior Epigastric Artery-Based Flaps

The VRAM flap should be considered as first choice for patients who are undergoing abdominoperineal resection. This is an ideal flap in total perineal resection, i.e., pelvic exenteration. The perforators of the deep inferior epigastric artery are marked over the abdomen using ultrasound Doppler and/or CT angiogram. Following completion of resection, the perineal defect is re-assessed in terms of the size of skin defect and the volume of pelvic cavity. The deep inferior epigastric vessels can be inspected through the abdominal wound and the required skin paddle is re-marked working out the required length of the pedicle ( Figs. 41.6–41.8 ).

The midline incision is extended superiorly and the lateral incision of the skin paddle is incised down to the rectus sheath. The rectus sheath is incised just laterally to the lateral row of perforators and a strip of the fascia is kept intact all along the rectus muscle. The flap, consisting of muscle, a strip of fascia, and an island of skin, is elevated. The deep inferior vessel is identified and carefully dissected right down to its origin. The lower attachment of the muscle is also divided, which helps in orienting the flap in the pelvic cavity and in delivering the skin paddle through the perineal wound.

The muscle is sutured to the pelvic floor. The skin paddle is usually larger than the defect hence it is de-epithelialized, leaving the exact amount of skin required. The skin paddle is inset keeping two drains, and the abdominal wound is also closed in layers. Postoperatively, the patient is mobilized as soon as possible.

Lateral Circumflex Femoral Profunda Artery-Based Flaps

The ALT flap is now a workhorse in reconstructive surgery, first described by Song et al in 1984 as a septocutaneous flap. The major advantages of this flap are that it provides a large amount of skin for harvest and that the pedicle is close enough to reach the perineum, but far enough to be away from diseased and irradiated areas of the perineum.

The blood supply of the ALT flap is dependent upon the perforators of the descending branch of the lateral circumflex profunda femoral artery. In general, a large skin flap can be raised but a width of up to 8 cm can be closed directly and any wider skin flap requires a skin graft. The perforators are assessed for a visible pulsation and for venae comitantes. Where of septocutaneous type, the vessels traverse the septum between rectus femoris and vastus lateralis muscles. If the perforators are of a muscular type, which usually comes from the vastus lateralis, that part of the muscle may also be included to add bulk to the flap. The flap is passed under the rectus femoris muscle and through the subcutaneous tunnel to reach the perineum, making sure that there is no tension on the pedicle. The perineal wound is closed in layers with a drain and the donor area is either closed directly, or with a skin graft.

Postoperatively, the patient may be nursed in slight flexion and also abduction of the thighs to prevent any compression on the pedicle, although this is rarely necessary. The patient is mobilised after 48 hours.

Gluteal Artery-Based Flaps

The gluteus maximus muscle is a large muscle of the buttock area. It has two dominant blood supplies as a type III muscle flap. The superior and inferior gluteal arteries arise from the internal iliac artery and they emerge on either side of the pyriform muscles. The superior gluteal artery supplies the upper part of the gluteus maximus and the inferior gluteal artery supplies the lower half. The inferior gluteal artery is a direct continuation of the internal iliac artery emerging below the pyrifomis muscle, accompanying the sciatic nerve, inferior gluteal nerve, the internal pudendal vessel, and posterior femoral cutaneous nerves. The cutaneous perforators of the inferior gluteal artery, about 8 ± 4, are concentrated in the middle third of the gluteal region, parallel to the gluteal crease. The SGAP or myocutaneous flaps would be suitable for the sacral part of the defect whilst the IGAP or myocutaneous flaps would be suitable for a large part of the perineum and also in pelvic exenteration ( Figs. 41.9–41.11 ).

These flaps are considered when VRAM or ALT flaps are not possible for reconstruction. When chosen for abdominoperineal reconstruction, the surgery requires two different positions of the patient. Initially, the resecting surgeon will carry out the abdominal part of the operation, including colostomy and urinary conduit, and the abdominal wound is closed. The patient is then positioned in the prone, jack-knife position. Using ultrasound Doppler, the lateral groups of perforators of the IGA are selected in the ellipse of the skin so that the pedicle is long enough to reach without tension. The skin flap is elevated from the lateral aspect and a small portion of the gluteus maximus muscle may be included, which not only adds to the bulk but also includes a number of perforators for the flap. Once the flap is islanded, the pedicle is dissected, ligating all other branches of the IGA. When the flap is transposed over the perineum, the deep layer is sutured with the pelvic floor and the skin is sutured in two layers of the perineum, with two drains.

Posterior Thigh Flap

The blood supply of this flap arises from the descending branch of the IGA. This flap contains the posterior cutaneous nerve of the thigh, which makes it a sensate flap. The course of the artery and the perforators can be mapped out by using ultrasound Doppler or by CT angiography. This helps in planning the required flap. A line is drawn from the ischial tuberosity to the lateral epicondyle of the femur. The skin paddle is centered at the midpoint of this line, with the width of the skin paddle being either the amount that can be closed directly or more if skin grafting is required. It is also possible to take two flaps or to use this in combination with other flaps. The flap is elevated by incising its lateral border and extending it towards the gluteal crease to expose the pedicle and following it up to its origin. Extra length can be obtained by dissecting the IGA. The flap may then be tunneled under the skin to the perineal defect and inset.

The postoperative regime is as described before. The donor scar of the IGAP flap does cause some discomfort for the patient during sitting for about 4–6 weeks postoperatively.

Medial Circumflex Femoral Profunda Artery-Based Flaps

Orticohea in 1972 and McCraw et al in 1976 described the gracilis myocutaneous flap. The gracilis myocutaneous flap is a type II muscle flap, the blood supply of which is from the ascending branch of the medial circumflex femoral artery. The skin flap paddle orientation is usually in the line of the gracilis muscle, but in recent years, following the paper from Yousif et al in 1992, a transverse orientation of the cutaneous paddle has been shown to be more reliable ( Fig. 41.12 ). This is now called a TMG or TUG flap. The muscular artery for the gracilis enters the muscle at about 8–10 cm from the pubic tubercle. The gracilis muscle can be used as a myocutaneous flap, or a muscle flap in combination with other skin flaps.

The gracilis myocutaneous flap is indicated for abdominoperineal resection with surgery carried out in the Lloyd Davies position. A skin paddle is drawn about 1–2 cm below and parallel to the groin crease and the inferior line is drawn depending on the amount of skin available for direct closure. This gives an ellipse measuring 18–20 cm in the anterior posterior direction.

The flap is elevated from anterior to posterior in the subfascial plane until the intramuscular septum between adductor longus and gracilis is encountered. The great saphenous vein is protected and preserved (i.e., not included in the flap). The adductor longus muscle can be identified easily and the fascia over the adductor longus muscle is included with the flap. The gracilis muscle is below adductor longus and the septum between the two can be easily separated by finger dissection, exposing the distal part of gracilis. The pedicle of gracilis, ascending branch of the medial circumflex profunda femoris artery, and the vein can easily be seen under the fascia.

Postoperatively, the patient is kept in a supine position with the legs slightly abducted, with a pillow under the knees to keep them flexed. After 24–48 hours, the drains are removed and the patient is mobilized.

The gracilis muscle may also be considered for functional transposition for perineal reconstruction by preserving the nerve to the muscle.

Introduction

Congenital anomalies of the genitalia result from a variety of genetic and prenatal causes. Abnormal genitalia are seen in patients with 46,XX chromosomes, 46,XY chromosomes, and mixed sex chromosomes. The expressions of these chromosomal abnormalities are the results of complex biological interplay. The manifestations range broadly and can affect multiple areas of human anatomy and physiology. In males, testosterone promotes development of the epididymis, vas deferens, and seminal vesicle; and Müllerian-inhibiting substance (MIS) prevents the maturation of the uterus, cervix, and upper vagina. In females, the absence of MIS allows maturation of the uterus, cervix, and upper vagina. At approximately the 9th week of gestation, normal males have produced enough testosterone to allow synthesis of DHT (dihydrotestosterone). DHT then induces fusion of the genital folds and promotes growth of the genital tubercle.

A defect in any of the genes or environmental milieu that affect this developmental process can result in abnormal genitalia. Certain developmental problems, such as bladder exstrophy, can simply disrupt normally developing anatomy. Other developmental problems, specifically those disrupting gender-specific development, result in anatomy that lies on a spectrum between normal female and male external genitalia. The Prader scale, originally described by Andrea Prader in 1954, is often used to describe this anatomy. It is a 5-level scale where 1 represents normal female external genitalia with clitoromegaly and 5 represents normal male external genitalia.

The type of reconstruction required for each patient varies depending on the cause of ambiguous genitalia and the resulting appearance. The most common causes of anomalous genitalia in those patients undergoing feminization procedures are congenital adrenal hyperplasia and mixed gonadal dysgenesis. Gender assignment in those with anomalous genitalia is crucial although the timing of surgery is a controversial issue. Some have suggested that the birth of ambiguous genitalia is a neonatal emergency and requires immediate intervention. Others have advocated delaying surgery until the patient can give informed consent. Most physicians, however, suggest performing surgery prior to the age of 3. Performing surgery during this earlier time increases compliance with dilatations and decreases parental concern about their child’s gender. The goals in vaginal reconstruction of ambiguous genitalia include preserving fertility, adequate sexual function, and eliminating the risk of malignancy in the intraabdominal gonads.

Nonsurgical Options

In cases of vaginal agenesis where a dimple of vaginal mucosa is present, often nonsurgical techniques are preferred to surgical creation of a neovagina. The Frank procedure involves the use of serial vaginal dilators. Using the dilator, pressure is placed on the vaginal dimple for 30 minutes to 2 hours per day. Over time the width and length of the dilator are increased to allow for a neovagina that is appropriately sized for sexual activity. Some discomfort is expected during dilatations, but after dilatations are complete, only intermittent dilatation is required if sexual activity is frequent enough to maintain patency. Edmonds et al document a 94.9% success rate with dilatation treatment in patients with Mayer–Rokitansky–Küster–Hauser syndrome. Ingram described a modification of the Frank procedure in which the serial dilators are attached to a bicycle seat upon which the patient sits. The modified positioning allows for improved patient comfort during serial dilatations.

Surgical Options

The reconstructive surgeon must consider multiple factors when planning the surgical creation of a neovagina. The location and size of the defect is the most important factor. However, it is also valuable to consider the patient’s position on the operating room table. The oncological surgeon may have completed the procedure with the patient in the prone or supine position. This may influence the options that are available without repositioning the patient. The type of incision, particularly whether a laparotomy incision was performed, and whether the initial incision remains open or has been closed, can alter the operative plan. The desired neovagina length and width should be based on the patient’s postoperative goals for sexual activity. The need for a connection between the neovagina and the uterus, when present, must be considered in congenital reconstruction.

Small defects of the vagina are amenable to primary closure if they do not significantly alter the length or width of the vagina. For larger defects, which are superficial or partial thickness, a skin graft can be considered. A vaginal conformer is often used to help promote take of the skin graft, which provides compression and immobilization of the graft to the underlying wound bed. In the pediatric gynecology literature, the preferred method for surgical creation of a neovagina in patients with vaginal agenesis is the Abbé–McIndoe procedure. First documented in 1938, this involves creating a space between with rectum and bladder and inserting a skin graft-lined mold to create the neovagina. This procedure requires the use of a mold or vaginal conformer for 6–12 months postoperatively and dilatations to maintain a vagina that can be used for sexual activity. Fussey et al. have also described the use of continuous negative pressure therapy to aid in skin graft take during vaginoplasty.

The pedicled rectus abdominis myocutaneous flap is the workhorse of vaginal reconstruction. Cordeiro described the use of the rectus flap for both partial posterior vaginal defects and circumferential upper two-thirds defects. The myocutaneous flap can be designed and harvested with a vertical or transverse skin paddle. The senior author (G.K.L.) prefers the vertical rectus abdominis myocutaneous (VRAM) flap as it is aligned with the midline incision that is most often used for a laparotomy incision, and, therefore, provides the greatest length of flap and greatest reach for the vaginal and perineal defect. The flap is based upon the deep inferior epigastric artery and can be passed directly into the pelvis/vaginal defect. Authors have recently described the harvest of the flap as a perforator flap for vaginal reconstructions noting decreased donor site morbidity. However, incorporation of the rectus muscle provides additional bulk and blood supply, which can be helpful in eliminating pelvic dead space and facilitating healing.

The pedicled gracilis myocutaneous flap , based on the medial femoral circumflex vessels, is another versatile option for vaginal and perineal reconstruction. The flap can be harvested with a transverse or longitudinal skin paddle. Cordeiro favored the longitudinal skin paddle for total circumferential vaginal defects while the transverse skin paddle can be used for labial reconstruction ( Fig. 41.13 ). It is important to note past reports of necrosis of the gracilis skin paddle when designed distally on the muscle down the thigh. Surgeons should note that the gracilis muscle tapers distally and becomes more tendinous, and that the blood supply of an overlying skin paddle at this level becomes less reliable. Hence, a skin paddle that incorporates the proximal major skin perforator, which enters at approximately 8–10 cm below the pubic ramus, is important for maintaining maximal perfusion.

The pudendal thigh flap was first published by Wee and Joseph in 1989, and is often referred to as the “Singapore flap.” The flap is an innervated fasciocutanous flap based off perforators from the internal pudendal artery, which travel from posterior to anterior. The skin flaps are designed over the proximal medial thigh and harvested deep to the fascia of the adductor muscles. Proponents of this flap cite the benefit of an inconspicuous donor site and more reliable blood supply than the gracilis myocutaneous flap. This technique has been used in the reconstruction of both congenital and acquired defects. This flap is of limited bulk, and should be considered for defects that do not require a large amount of dead space obliteration.

Intestinal conduits , including the colon and jejunum, have also been utilized for vaginal reconstruction. This type of reconstruction is more widely documented for congenital defects. Erman Akar et al described their experience with vaginal reconstruction for congenital defects (33 of 34 patients) using a free vascularized jejunal flap. At a mean follow-up of 50 months, the authors noted satisfactory vaginal depth and diameter. However, six patients noted jejunal hypersecretion post-reconstruction and 10 patients required two lengths of jejunum opened along its antimesenteric border in order to increase luminal diameter. In contrast, the benefit of the colon in vaginal reconstruction is its larger diameter in comparison to the jejunum. Lima et al reviewed their 34-year experience treating 46 cases of vaginal agenesis with sigmoid colon interposition. While they noted no cases of excessive mucus production, eight patients had stenosis, six of whom required operative intervention. Of note, 34% of the group was sexually active at a mean follow-up of 12 years. Anecdotally, some patients may report a foul odor with the use of intestinal conduits as a result of mucus secretions.

Omental flaps , which have been used to treat rectovaginal and vesicovaginal fistulas as well as to close off the pelvic inlet after pelvic exenteration, can be modified for vaginal reconstruction. Authors have documented the use of a cylindricized omental flap based off the left gastroepiploic artery with a skin graft for neovaginal creation. The minimal donor site morbidity and ease of flap harvest are among the benefits of this flap. However, like other skin graft-based reconstructions, stenting is necessary for up to 6 months postoperatively to maintain adequate vaginal depth and to prevent strictures and stenoses.

The anterolateral thigh (ALT) flap has emerged as another option for vaginal and perineal reconstruction. Based on the descending branch of the lateral femoral circumflex artery, the ALT flap is a versatile flap for reconstruction. The flap can be harvested as a fasciocutaneous, an adipofascial, or a musculocutaneous flap. This versatility is beneficial for reconstruction in the perineum where dead space obliteration may be required or thinner pliable tissue may be ideal. The flap is tunneled beneath the rectus femoris and sartorius to improve pedicle length.

Complications

The most common complication after vaginal reconstruction is delayed wound healing or dehiscence. Other more devastating complications include: flap necrosis, fistula formation, and pelvic abscesses. Strictures may develop that require dilatations or revision surgery. Donor site infections may also be seen, as vaginal reconstruction is not a clean procedure. It is advised to use a separate clean set of instruments for flap harvest outside of the abdominal cavity if practical. After vaginal reconstruction with a rectus abdominis myocutaneous flap or an intestinal conduit, neovagina prolapse can occur which becomes bothersome to the patient. This may require secondary correction with sacral suspension.