Keywords anorectal malformation - vaginal agenesis - posterior sagittal anorectoplasty - vaginoplasty
Introduction
Anorectal malformations (ARMs) are rare congenital defects with an estimated worldwide
incidence of 2 to 6 per 10,000 live births.[1 ] They comprise a wide range of pathologies that may involve other parts of the gastrointestinal
tract as well as urinary and genital tracts.[2 ]
[3 ]
[4 ]
[5 ]
[6 ]
[7 ]
[8 ]
[9 ] The most common type of ARM in female patients is a rectovestibular fistula. The
incidence of vaginal agenesis associated with ARM is even lower.[4 ] The approach to this combination was first described by Cohn and Murphy via a combined
laparotomic and perineal operation.[10 ] The use of rectovestibular fistula as a neovagina has also been reported in combination
of a posterior sagittal anorectoplasty (PSARP),[2 ] as described by Levitt et al.[4 ] We describe the case of a 1-year-old girl with ARM and rectovestibular fistula in
whom we chose to leave the rectum-rectovestibular fistula to function as a neovagina,
while the sigmoid colon was relocated via modified PSARP, according to Liem and Hau,
and Liem and Quynh technique.[11 ]
[12 ]
Case Report
The previous term infant (birth weight 3.1 kg) was admitted to the Pediatric Surgery
Service at Saint Damien Pediatric Hospital, Port-au-Prince, Haiti, with a diagnosis
of vaginal agenesis associated to ARM with rectovestibular fistula. Until 10 months
of age, the infant defecated through the rectovestibular fistula that required dilations
even though it had a considerable caliber. Two months prior to clinical admission,
she received a descending colostomy with distal mucous fistula. No other obvious malformations
and a normal sacrum were found. Due to the lack of resources at the local hospital,
no additional diagnostic imaging, for example, magnetic resonance imaging, was performed.
We chose to leave the rectovestibular fistula in situ to function as a neovagina and
to perform a PSARP,[2 ]
[4 ] modified at preserving the anal sphincter as reported by Liem and Hau, and Liem
and Quynh.[11 ]
[12 ] The patient was placed in a prone jackknife position. After locating the anal sphincter
by using a neurostimulator, a posterior sagittal incision of the cutaneous and subcutaneous
planes was made 1 to 2 cm over the coccyx to the superior limit area of the anal dimple.
The dissection was deepened while paying attention to the midline, to avoid injuries
to muscles and nerve fibers, and arrested at the level of the upper limit of the muscle
complex. The muscle complex was identified and its lower part was retracted downward
to expose the posterior wall of the rectum ([Fig. 1 ]). The fibrotic bands between the rectal wall and the coccyx were divided and the
coccyx removed aiming at gaining extra space. The rectum appeared considerably dilated
to the extent that not all its circumferences could be isolated. As a consequence,
it was isolated only from its lateral sides and the anterior surface of the sacrum
until the peritoneal reflection which was opened in view of the subsequent laparotomy.
Fig. 1 The lower part of the muscle complex was retracted down to expose the posterior wall
of the rectum.
After having temporarily closed the posterior sagittal skin incision to minimize the
risk of bacterial contamination, the patient was placed in supine position to open
the abdomen through a Pfannenstiel incision. The rectum, which was abnormally dilated
until 1 to 2 cm beyond the peritoneal reflection, continued as sigmoid colon whose
caliber appeared suddenly normal ([Fig. 2 ]). The rectouterine Douglas' pouch was explored; while ovaries were located with
fallopian tubes presenting cordlike structures, instead no structures resembling vagina
and uterus were found.
Fig. 2 Anatomy of the patient.
The dilated rectum was surgically separated from the sigmoid colon and closed; the
sigmoid colon was only temporarily sutured to avoid fecal contamination ([Fig. 3 ]).
Fig. 3 Sigmoid colon surgically separated from the dilated rectum.
After binding and dissecting some branches of its vascular arcade, the sigmoid colon
was then mobilized, as it needed to be easily passed without traction through the
retrorectal space into the previously opened posterior sagittal space ([Fig. 4 ]), which was reopened at this point.
Fig. 4 Mobilized sigmoid colon passed into the posterior sagittal space.
Once the suprapubic incision was sutured and the patient was again in the same prone
position as before, a second small inverted cutaneous Y-shape incision was made on
the anal dimple, after reconfirming the location of the underlying anal muscle complex
using the neurostimulator ([Fig. 5 ]). Our technique was different from the original technique of PSARP described by
Peña and Devries, which envisages to separate the sphincter muscle complex in the
midline.[2 ] In contrast, we created a tunnel in the center of the sphincter muscle complex through
a gentle and progressive dilation of its muscle fibers using Hegar dilators (size
6–12) ([Fig. 6 ]) until reaching an acceptable diameter to enable the mobilized sigmoid colon to
go through it.
Fig. 5 The center of the sphincter complex is defined using a neurostimulator.
Fig. 6 Progressive dilation of the tunnel created in the center of the sphincter complex.
Consequently, the sigmoid colon, that managed to pass through the dilated tunnel of
the sphincter muscle complex, was sutured to the external sphincter and to the margins
of the small Y-shape cutaneous incision that had already been made in the anal dimple
by using interrupted absorbable stitches ([Fig. 7 ]).The posterior sagittal incision was then closed. Postoperatively, the neoanus was
gradually dilated using Hegar dilators from the second week after the surgery for
a total period of 1 month. The colostomy was closed after 6 months.
Fig. 7 The sigmoid colon is passed through the dilated tunnel of the sphincter complex and
a neoanus is created.
No complications were observed during the early postoperative period. Neither anal
stenosis nor other local and general complications were observed.
Two years after the anoplasty and at the age of 3 years, the parents reported that
a few months earlier the girl stopped using diapers as she had achieved good bowel
control and always evacuated spontaneously. So, no complications occurred such as
fecal incontinence (not even partially), no constipation or mucosal prolapse, nor
urinary incontinence. The rectovestibular fistula, that had become the vagina introitus,
appeared relatively wide and easily to explore ([Fig. 8 ]).
Fig. 8 Neoanus and neovaginal introitus at 2.6 years of age.
Discussion
Our case is a subtype of Mayer–Rokitansky–Kuster–Hauser syndrome,[6 ]
[13 ] caused by embryologic underdevelopment of the Mullerian duct with resultant agenesis
of vagina and uterus. Vaginal agenesis associated with ARM is uncommonly seen.[4 ]
[5 ]
[6 ]
[7 ]
[9 ]
[10 ]
[13 ]
[14 ]
[15 ]
[16 ]
[17 ] Banu et al[18 ] reported 5 patients with a rectovestibular fistula and absence of vagina in their
series of 563 cases.
For what concerns the reconstruction of vaginal agenesis in cases of vaginal agenesis
without ARM, the first-line approach, based on safety reasons, is the primary vaginal
elongation by dilations, sometimes with local estrogen, known as Vecchietti procedure[13 ]
[19 ]; if no satisfactory results are achieved, during adolescence can be indicated an
intra-abdominal traction applied to the perineal membrane, causing invagination over
the course of a week. This technique often produces an inadequate vaginal length that
might interfere with normal sexual life. Due to these reasons, other surgical options
include vaginoplasty using a part of the ileus or sigmoid colon.[5 ]
[6 ]
[7 ]
[9 ]
[13 ]
[15 ]
[16 ]
In 1956, Cohn and Murphy[10 ] proposed for the time to correct vaginal agenesis in ARM rectovestibular fistula
type, using the rectum-rectovestibular fistula in situ as a neovagina. In other reports
on vaginal agenesis, an abdominoperineal approach[14 ]
[17 ] and a PSARP according to Levitt et al were used.[4 ]
[20 ]
This was also our decision: the vaginal agenesis was corrected using the rectum including
the rectovestibular fistula to function as the vagina. The sigmoid colon was pulled
through and relocated to be the neoanus,[2 ] as proposed by Levitt et al,[4 ] including laparotomy, but preserving the anal sphincter, according to Liem and Hau,
and Liem and Quynh.[11 ]
[12 ]
At 3 years of age follow-up, the patient showed good bowel control, which generally
at that age cannot be completely achieved.[21 ] No clinical complications such as constipation or fecal incontinence were reported.
Although it represents a unique case, we believe that such satisfactory functional
results probably also derived from the surgical technique used besides the fact that
no lesions involving the sacrum were observed; unlike what takes place in the Peña
and Devries' PSARP technique, based on an incision of the sphincter muscle complex
in the midline,[2 ] the sphincter muscle complex was not divided and the sigmoid colon was pulled through
a tunnel created at its center. Having left the sphincter muscle complex untouched
leads us to hypothesize that the function of this important structure was preserved;
this technique has already been reported.[11 ]
[12 ]
Differently from our strategy of using the in situ rectum as a neovagina, another
clinical option was to separate the rectum from urethra and relocate it within the
limits of the sphincter mechanism. However, the major disadvantage of this technique
is that later a more time-consuming surgery for vaginal reconstruction is required,
which can also be an intervention of higher complexity. In addition, the separation
of the rectum from the urethra might provoke denervation of the lower urinary tract
as well as risks of denervation involving the rectum.[4 ]
As the rectum shoved a considerable dilation, we added a suprapubic laparotomy before
performing a modified PSARP with preservation of an intact anal sphincter. If the
rectum had a normal caliber, we would have pulled down the proximal rectum to the
neoanus ([Fig. 9 ]).
Fig. 9 Sketch of the one-stage posterosagittal approach, preserving the muscular sphincter
complex (Liem and Hau, and Liem and Quynh technique), to correct vaginal agenesis
and anorectal malformation with rectovestibular fistula.
The final result of our procedure was an introitus situated rather anteriorly in the
vulva probably due to extra space left by the missing vagina whose space might have
been taken.
We hope that the future sexual function and satisfaction will be beneficial as the
terminal nerves to the vulva and rectum involved were not subjected to any surgical
manipulation, unlike a lot of other surgical techniques currently used for vaginal
reconstruction.
Clearly, the diameter of the new vaginal introitus will have to be assessed during
puberty; in the case of insufficient diameter, an event highly expected to occur,
it might be widened using the wide walls of the rectovestibular fistula.
Also, at long-term follow-up, the sensitivity of the new vaginal introitus will have
to be assessed.
Conclusion
Our surgical strategy based on the decision to leave the rectum in situ with its rectovestibular
fistula used as a neovagina before creating a neoanus via a PSARP may provide an effective
alternative to other vaginal reconstruction strategies using more complex reconstruction
techniques.
