An Unusual Case of Type A Posterior Cloaca Associated with 46XX Disorder of Sexual Differentiation with Y Duplication of Urethra.

We report an infant reared as a girl who presented with ambiguous genitalia and urine coming per rectum. On examination, she had minimal clitoromegaly with labial fusion and Y urethral duplication. On investigations, genetic, metabolic, and endocrine causes for disorder of sexual differentiation were ruled out. This girl was operated via a posterior sagittal approach. This case was unique in that the urogenital sinus was deviated posteriorly and opened in the anterior rectal wall and the accessory urethra opened in clitoris, along with ambiguity of external genitalia, thus making it a rare variant of the posterior cloaca. The diagnosis requires a high index of suspicion in clinician and a meticulous examination of the external genitalia. Very little literature is available for this rare anomaly. Few reports have classified them as female pseudohermaphroditism with cloacal and urogenital sinus defects. Hence, we hereby discuss and review the literature for previously reported cases. Copyright:

INTRODUCTION

Posterior cloaca is a type of persistent cloaca when the common channel of urethra, vagina, and rectum deviates posteriorly and opens at the anal site or just anterior to it or anterior rectal wall. Type A is described as a single perineal opening at the anal site or a little anterior to it. The finding of two perineal orifices, one being the rectum and a second one being the urogenital sinus (UGS) located immediately anterior to the anus, was arbitrarily called posterior cloaca type B.[12] Initial diagnosis may be missed in cases of the posterior cloaca. Only after retraction of labia can one notice a single perineal opening, that too in presence of accessory urethra, diagnosis can only be made after investigating with cystogenitoscopy, as in our case. Peña and Kessler described posterior sagittal transanorectal route for the repair of posterior cloaca.[3]

CASE REPORT

A 4-month infant, reared as a girl, born preterm out of a nonconsanguineous marriage presented with complaints of urinary incontinence and passing urine both from clitoris and rectum, more per rectally since birth. She had a history of recurrent urinary tract infections. The child had a normal anal opening with normal corrugations and urine dribbling per rectum. She had a small introitus with minimal clitoromegaly with a single small opening in the clitoris and absent labia minora [Figure 1]. Ultrasound of the pelvis suggestive of thickened urinary bladder with bifid uterus and hydrocolpos. On evaluating the patient by examination under general anesthesia and cystogenitoscopy, she had a normal anal opening within muscle complex, opening of UGS was 5 mm from anal verge on the anterior wall of the anal canal and 1 cm proximal to opening of UGS were two vaginal openings within the common channel with urethral opening in the septum between vaginae. Opening of the accessory urethra was seen 2 mm distal to the urethral opening which opened distally at the tip of clitorus with around 1 cm length of accessory urethra being hypoplastic. On micturating cystourethrography, she had a grade II reflux on the left side and both dorsal and ventral urethra were seen. Diverting right transverse colostomy was made to prevent recurrent UTI and started on distal stoma washouts while awaiting definitive surgery. Six months later, she underwent definitive surgery after adequate bowel preparation in a prone jackknife position in the form of posterior sagittal anorectovaginurethroplasty. Posterior sagittal incision was taken from coccyx circumscribing posterior cloaca to the vestibule. Cloaca mobilized all around and opening of UGS noticed on the anterior wall of the rectum. After around 1 cm submucosal dissection, UGS separated from the rectum and split in the midline to identify accessory urethral opening, dominant urethral opening, and two vaginal openings [Figure 2]. Accessory urethra was mobilized and distal opening was cored and catheterized with 6 F foley catheter which was negotiated into normal urethral opening in vaginal septum and urethrourethrostomy was done. Total UGS mobilization was done to bring the vaginal opening to the surface [Figure 3]. Rectum placed in sphincter muscle complex (SMC) and SMC closed over it and posterior sagittal incision closed with neoanus formation. Posterior wall of UGS closed and urethra spatulated and neourethra created in vestibule, posterior wall sutured with anterior wall of UGS. Perineal body was created and vaginoplasty done using local skin flaps and introitus was reconstructed. Postoperative catheter was kept for 15 days and there were no wound complications [Figure 4] Stoma closure was done 6 weeks later with good anal continence [Figure 5].

Figure 1

Clinical photo of the perineum

Figure 2

Intraoperative view

Figure 3

Rectum, vaginae, and reconstructed urethra

Figure 4

Postoperative image

Figure 5

Representative diagram

DISCUSSION

When the common channel of urethra, vagina, and rectum deviates posteriorly and opens at the anal site or just anterior to it or anterior rectal wall, it is called a posterior cloaca. There are a few case reports in literature with female pseudohermaphroditism with bicornuate uterus and posterior cloaca.[1] Idiopathic XX disorder of sexual differentiation (DSD) with associated cloacal or UGS anomalies has also been included within the broad group named female pseudohermaphroditism with cloacal and urogenital sinus defects (FPHCD). These anomalies were first described by Broster in 1956 and later Jones classified these anomalies as special types of female pseudohermaphroditism.[24]

The exact incidence of FPHCD is uncertain, although Karlin et al. found 4 such cases among 54 patients with persistent cloaca. Hendren has described these patients as distinct entities within the spectrum of cloacal defects.[56] Peña and Kessler and Hendren have described similar deformities as posterior cloaca in literature.[36] It has been postulated to have exposure to virilizing substances during early fetal life resulting in masculinized external genitalia. Postnatally, they have normal adrenal hormone levels and at puberty feminize normally with regular ovulation and menstruation.[7]

These conditions are associated with malformations of the internal genitalia, urinary, and gastrointestinal systems. In addition, skeletal anomalies such as talipes equinovarus, vertebral defects, and sacral agenesis have been documented in certain cases.[8]

The index case is described as a 46 XX DSD with type A posterior cloaca, as in this case, there was the ambiguity of external genitalia with 46 XX karyotype and UGS was present in the anterior wall of the rectum which was normally placed with an accessory urethra in introitus.

The etiology of this constellation of defects is uncertain. McMullin and Hutson suggested that an early anomaly well before sexual differentiation may prevent the genitalia from acquiring their normal androgen-dependent growth controls.[9] Escobar et al. described this condition as a “urorectal septum malformation sequence” resulting from the failure of migration to or fusion of the urorectal septum with the cloacal membrane.[10] Gardner and Nelson designated this continuum of defects the “cloacal dysgenesis spectrum” and suggested that the defects presumably arise from abnormalities of mesodermal migration and differentiation in the caudal developmental field.[11] Bellinger and Duckett believed that abnormal descent of the Mullerian duct resulted in posterior displacement of the introitus, allowing the accessory urethra to form and resulting in an unusually prominent clitoris.[12]

This rare entity has many similar characteristics, including a prominent clitoris, double urethra with a vaginal and rudimentary phallic urethra, labial anomalies and a posterior-placed vaginal introitus, varying degrees of urinary tract obstruction, and uterine and vaginal abnormalities. The degree of phallic differentiation varies. In some cases, the phallus was enlarged, while in many, its prominence was owed to a lack of caudal curvature due to the ventral development of a phallic urethra. Bellinger and Duckett suggested that complete urethral development without chordee makes the phallus prominent as in erection.[12] Rarely, the phallic body contains corpora cavernosa and corpus spongiosum, while in most of the cases, there will be no corpus spongiosum. The prominent phallic body can be explained by well-formed corpora and complete development of the phallic urethra till the tip of the phallus.

Although complete urethral duplication has been seen in many cases of this anomaly, “Y” type of duplication has also been reported.[7] In the majority of cases, the phallic urethra is severely stenotic and considered nonfunctioning accessory urethra.

These patients require a diverting colostomy followed by definitive management either through a complete primary repair or a staged repair with one stage as of clitoroplasty, disconnection of phallic urethra, anterior transposition of urethrovaginal canal, and relief of obstructive uropathy. In the second stage, the urethra and vagina should be separated and repaired using a perineal skin flap.[7] If the vagina falls short to reach the perineum, then it may have to be substituted with a colonic graft.[13] Conventionally, excision of the accessory urethra has been recommended owing to its functional inadequacy.[3] However, few authors have proposed that the accessory urethra should be preserved and its proximal and midpart used to create a mucosa-lined vestibule, which can be used to bridge the distance between the new urethral opening and the apex of the vaginal introitus, creating a more natural-appearing and functioning vestibule.[14]

The urethral reconstruction involved incorporation of the both limbs of the urethra in the index case. The proximal part of accessory urethra was joined to the other limb of the urethra. This helped in placing the urethra just below the clitoris in its normal position and the distal part of the accessory urethra was laid open to line the vestibule. The vaginoplasty was done utilizing the UGS common channel to reach the perineum and local skin flaps.

CONCLUSION

Posterior cloaca is a rare condition and its association with 46XX DSD with Y duplication of urethra is even rarer. Anatomical variation is the rule rather than exception and the correction should be tailored to individual patients. Creation of a good urethral channel without incontinence and preserving anal continence are the goals of the corrective surgery.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.