Urogenital Sinus and Cloacal Anomalies
RICHARD C. RINK
JEFFREY A. LESLIE
MARTIN KAEFER
Anomalies of the urogenital sinus occur on a spectrum ranging from a mild distal communication between the urethra and vagina to a very complex confluence between the urethra, vagina, and rectum. For this last-mentioned complex group, a distal common channel for all of these structures drains to a single perineal opening (Fig. 104.1A). The clinical presentation of this single opening results from persistence of the cloaca and is essentially a severe urogenital sinus abnormality with a high imperforate anus (Fig. 104.1B). In addition to a more bizarre and diverse internal anatomy, patients with cloacal anomalies have a high incidence of other serious midline congenital anomalies. Important elements of baseline evaluation and surgical management of urogenital sinus and cloacal anomalies are discussed in detail in this chapter.
 FIGURE 104.1 A: Urogenital sinus. The confluence of the vagina with the urethra is near the bladder neck and thus “high.” A Fogarty catheter is in the vagina. B: Cloacal anomaly with the urethra, vagina, and rectum all exiting a single perineal opening. (From Indiana University School of Medicine, Office of Visual Media, with permission.) |
Urogenital sinus abnormalities (no rectal involvement) in general occur in one of two forms: pure urogenital sinus anomalies and females with disorders of sexual development (DSD) conditions. The latter group is much more common.
In these children, surgical management must address not only the urinary and vaginal communication but also the virilization of the clitoris and labia.
DIAGNOSIS
The majority of children with urogenital sinus abnormalities are detected at birth due to genital ambiguity. The initial evaluation in this group of children requires a team approach to rapidly identify the etiology and requires rapid chromosomal and endocrinologic studies. The history and physical examination are often helpful in establishing a correct diagnosis. Congenital adrenal hyperplasia (CAH) secondary to 21-hydroxylase deficiency is by far the most common etiology. Some children may be identified antenatally on ultrasound by noting a fluid-filled mass (distended vagina) posterior to the bladder and indeterminant genitalia. Persistence of the cloaca is suspected in utero when large fluid-filled pelvic structures are noted associated with bilateral hydroureteronephrosis, oligohydramnios, and ascites. A 46XX karyotype is found. Hydrocolpos due to retention of urine and secretions results in upper tract distention, and ascites occurs due to retrograde flow through the genital tract into the peritoneum. The rectum and bladder may also be filled with urine, giving rise to the other fluid-filled structures.
Prematurity and multiple congenital defects are common in children with cloacal anomalies. Initial evaluation of these children should therefore include medical stabilization and evaluation for midline abnormalities. Abdominal distention is common and may result in respiratory embarrassment. Cardiac, renal, and upper gastrointestinal anomalies and spinal dysraphism are frequently identified. Although these infants are uniformly female, ambiguity of the genitalia may occur and should be investigated. A single perineal opening is noted anteriorly, and the anus is absent. The perineum is in general flat with variable amounts of labial tissue mounded around the anterior orifice. Occasionally, a prominent phallic structure is found. The buttocks are often poorly developed, and the sacrum may be deficient on abdominal plain film.
Renal ultrasound reveals anomalies of number and fusion. Magnetic resonance imaging (MRI) clarifies the complex pelvic relationships, evaluates the structural quality of the sphincter complex, and defines the anatomy of the lumbosacral spine and distal spinal cord. A gender assignment committee is convened for all children with genital ambiguity. This committee includes an endocrinologist, geneticist, pediatric urologist, neonatologist, psychiatrist/psychologist, and the family. The child must be stabilized. Genitography to help determine the anatomy (i.e., length of common sinus, location of vaginal confluence, status of bladder, presence or absence of vesicoureteral reflux, or vaginal duplication) has routinely been used in urogenital sinus and cloacal anomalies. We have recently shown that the anatomy is delineated correctly in only 72% of CAH patients (1). Patients with cloacal anomalies have a communication between the urogenital tract and rectum, and vesicoureteral reflux is commonly identified. Endoscopy is imperative to understand this complex anatomy. Ultrasonography of the pelvis and kidneys is also of help to identify the uterus, ovaries, and any vaginal distention, or, in the case of cloacal anomalies, it may reveal hydronephrosis or increased echogenicity suggestive of renal dysplasia. The adrenal glands in CAH may be prominent with a cerebriform appearance (2). MRI of the pelvis is an excellent tool to determine pelvic anatomy and note the presence of lumbosacral spinal cord anomalies that may be present.
Pure urogenital sinus anomalies are in general not detected early because of normal external genitalia. These patients are usually found at puberty with hydrometrocolpos or difficulty with tampon insertion. Some children are identified earlier with incontinence and urinary tract infection (UTI) from urine pooling within the vagina. Those with pure urogenital sinus anomalies are also more likely to have other organ system abnormalities than those with a urogenital sinus associated with DSD.
INDICATIONS FOR SURGERY
It is very important for the reader to understand that there are many controversies associated with the care of children with genital ambiguity. The controversies primarily involve the role of surgical management including timing, types of repairs, outcomes—particularly sensory loss, and lack of patient consent. Ideal surgical timing for those with DSD is yet to be defined (3). Surgery for DSD generally involves clitoroplasty, labioplasty, and vaginoplasty. The timing of the surgery is the most controversial with proponents falling into one of four groups: (a) all components done in infancy, (b) clitoroplasty and labioplasty in infancy with delayed pubertal vaginoplasty, (c) all components done at puberty, and (d) no surgery unless the patient is of age to request it. There are advantages and disadvantages to each of these options. For CAH and cloacal anomalies, surgery is most often performed in infancy. We believe strongly that no family should be talked into surgery but should rather be given all advantages and disadvantages of the various options and support in their decision-making process. Creighton et al. (3) have noted that the idea of “doing nothing” can be a stressful concept for the parents. Clearly, gender assignment when the individual’s ultimate gender identity is unknown is a challenge and is at the core of this controversy (4). The family should also be given access to support groups such as the CARES Foundation, Accord Alliance, and MAGIC Foundation to aid in this complex decision.
For the purposes of this presentation, we will assume that the family and the gender assignment team agree to proceed with surgery. Although the majority in the United States elect surgery as an infant, it is imperative for the family to know that this “single stage surgery” may require secondary vaginal surgery at puberty most commonly due to introital or vaginal stenosis. This is usually a minor procedure. Even among proponents of early clitoroplasty, labioplasty, and vaginoplasty, it is understood that in the child with a very high, very small vagina, it may be more appropriate to postpone vaginoplasty until puberty. All techniques described herein are applicable to the infant or pubertal child. We are in agreement with others that these procedures are technically more challenging after the onset of puberty (5).
DECOMPRESSION THERAPY
While most of those with a urogenital sinus undergo reconstruction in the first few months, the complex nature of cloacal anomalies and their high incidence of other congenital defects may necessitate a delay in formal reconstruction while the
child is stabilized. Certainly, temporary diversion of the gastrointestinal tract by colostomy is essential, and decompression of the urinary tract may be required. This may be done by clean intermittent catheterization, but if this is not adequate, a temporary cutaneous vesicostomy or vaginostomy may be needed. There has been concern historically that vaginostomy may tether the vagina to the abdominal wall making later vaginoplasty more difficult. However, this has more recently been challenged by Levitt and Pena (6,7), and vaginostomy has been valuable in some patients in our hands. In the current era of Malone antegrade continence enema (MACE appendicocecostomy) procedures to achieve fecal continence, nearly all will ultimately undergo complete reconstruction, including a rectal pull-through.
child is stabilized. Certainly, temporary diversion of the gastrointestinal tract by colostomy is essential, and decompression of the urinary tract may be required. This may be done by clean intermittent catheterization, but if this is not adequate, a temporary cutaneous vesicostomy or vaginostomy may be needed. There has been concern historically that vaginostomy may tether the vagina to the abdominal wall making later vaginoplasty more difficult. However, this has more recently been challenged by Levitt and Pena (6,7), and vaginostomy has been valuable in some patients in our hands. In the current era of Malone antegrade continence enema (MACE appendicocecostomy) procedures to achieve fecal continence, nearly all will ultimately undergo complete reconstruction, including a rectal pull-through.
 FIGURE 104.2 Total lower body preparation. A: Supine position allows access to perineum and abdomen. B: Child has been rotated prone, allowing access for a posterior sagittal approach. |
SURGICAL TECHNIQUE
All children with a very high vaginal confluence or a cloacal anomaly receive a polyethylene glycol electrolyte solution bowel preparation and prophylactic parenteral antibiotics preoperatively. Those with a low to midlevel confluence and most CAH patients receive only a preoperative enema and broadspectrum antibiotics. CAH children must receive “stress dose” steroids prior to surgery.
Endoscopy is performed with the child in the lithotomy position. This is one of the most important steps in reconstruction, as it defines the level of vaginal confluence and allows identification of any other lower genitourinary pathology, such as vaginal duplication, ectopic ureter, and so forth. We believe that the distance of the vagina from the bladder neck is the most critical aspect and dictates the type of vaginoplasty. Endoscopy also allows placement of a Fogarty catheter into the vagina, which is left indwelling with the balloon inflated. Correct placement is confirmed by repeating endoscopy. The Fogarty balloon will aid in identification of the vagina during the reconstruction. A separate small Foley catheter is passed into the bladder.
Historically, urogenital sinus surgery has been performed with the child in the lithotomy position. While this position is acceptable, we have found it much easier to prepare the entire lower portion of the body circumferentially to allow access to the abdomen and perineum and to allow the child to be supine or prone (Fig. 104.2A and B). The supine portion of the procedure is done with the child “frog-legged,” with the buttocks elevated on towels. This position dramatically improves visualization for the surgical assistants and does not hinder the surgeon. By far the most common group of patients with a urogenital sinus anomaly to require surgical reconstruction is the group with CAH, who have not only a urogenital sinus but also virilization of their external genitalia. This includes clitoral hypertrophy, absence of the labia minora, and anteriorly placed labia majora. Therefore, most patients will undergo clitoroplasty, labioplasty, and vaginoplasty.
Clitoroplasty
In cases of genital ambiguity, the operation begins with placement of a traction suture in the glans clitoris. Using a skin scribe, the proposed incisions are outlined as shown in Fig. 104.3. Historically, a very wide-based inverted U-shaped perineal flap has been created. Improved cosmesis occurs, however, if the flap has a narrower base similar to an omega (8), avoiding the appearance of a triangular introitus. After injecting 0.5% lidocaine
with 1:200,000 epinephrine subcutaneously along the proposed suture lines, the clitoroplasty is begun. The initial incision is carried out dorsally at the junction of the inner preputial surface with the outer clitoral skin. This preserves the inner preputial skin for a clitoral hood and maximizes sexual sensitivity. The entire clitoris is degloved by creating a plane between the Buck fascia and the dartos circumferentially. Ventrally, the incision is carried around the urogenital sinus meatus. The rounded apex of the perineal flap should extend to near the meatus. In situations where the urogenital sinus meatus is at the base of the clitoris, parallel incisions on either side of the urogenital sinus plate will allow its preservation for later use in the reconstruction.
with 1:200,000 epinephrine subcutaneously along the proposed suture lines, the clitoroplasty is begun. The initial incision is carried out dorsally at the junction of the inner preputial surface with the outer clitoral skin. This preserves the inner preputial skin for a clitoral hood and maximizes sexual sensitivity. The entire clitoris is degloved by creating a plane between the Buck fascia and the dartos circumferentially. Ventrally, the incision is carried around the urogenital sinus meatus. The rounded apex of the perineal flap should extend to near the meatus. In situations where the urogenital sinus meatus is at the base of the clitoris, parallel incisions on either side of the urogenital sinus plate will allow its preservation for later use in the reconstruction.
 FIGURE 104.3 Proposed initial incisions. Notice the omega-shaped perineal flap. The meatus is encircled. (From Indiana University School of Medicine, Office of Visual Media, with permission.) |
The perineal flap is elevated with its underlying subcutaneous and adipose tissue to expose the urogenital sinus. Dorsally, the suspensory ligament is divided and the bifurcation of the corporal bodies is exposed ventrally. With the entire clitoris now exposed, a tourniquet is placed at its base. A vertical ventral midline incision is made along the entire length of each corporal body to the glans (9) (Fig. 104.4A). The erectile tissue is exposed and excised, with care taken not to injure the Buck fascia, the tunica albuginea, the neurovascular bundle, or glans. This is performed bilaterally from the glans to the level of the bifurcation (Fig. 104.4B). The proximal end of each corporal body is oversewn with 5-0 polyglycolic acid sutures to prevent bleeding. With the Buck fascia folded, the glans is now secured to the corporal stumps with 5-0 polydioxanone sutures. We had previously sutured the glans to the pubis but found that this technique prevents appropriate concealment of the glans. At times, the glans is quite large, but one should resist aggressive glans reduction. If any reduction is done, it should only occur on the ventral aspect of the glans to prevent loss of sensation (10).
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