Pediatric Surgery, AlSadik Hospital, Qatif, Saudi Arabia
Hydrocolpos is the distension of the vagina caused by accumulation of fluid due to congenital vaginal obstruction.
The obstruction is often caused by an imperforate hymen or less commonly a transverse vaginal septum.
The fluid consists of cervical and endometrial mucus.
In rare instances the hydrocolpos is secondary to urine accumulated through a vesicovaginal fistula proximal to the obstruction or due to the presence of urogenital sinus with collection of urine.
The term hydrometrocolpos is when hydrocolpos is associated with fluid accumulation in the uterus.
Vaginal atresia is a congenital abnormality of the female genital system.
It represent a spectrum of malformations ranging from total vaginal agenesis to vaginal atresia.
30.2 Imperforate Hymen
Imperforate hymen is the most common and most distal form of vaginal outflow obstruction.
An imperforate hymen is a congenital malformation characterized by a hymen without an opening which completely obstructs the vagina (Fig. 30.1).
A clinical photograph showing a newborn with imperforate hymen. Note the bulging hymenal membrane
It is caused by a failure of the hymen to perforate during fetal development.
It is most often diagnosed in adolescent girls when menstrual blood accumulates in the vagina (hematocolpos) and sometimes also in the uterus.
In adolescent females:
The most common symptoms of an imperforate hymen are cyclic pelvic pain and amenorrhea.
The cyclic pain is secondary to hematocolpos.
Other symptoms include urinary retention, constipation, back pain, nausea, and diarrhea.
The hymen originates from the embryonic vagina buds from the urogenital sinus.
As a consequence, the hymen is a composite of vaginal epithelium and epithelium of the urogenital sinus interposed by mesoderm.
Once the hymen becomes perforated or forms a central canal, it establishes a communication between the upper vaginal tract and the vestibule of the vagina.
Normally, there are anatomic variations of the patent hymen.
The most common being an annular or circumferential hymen in which the hymen completely surrounds the vaginal orifice and has a central opening.
Other appearances of the hymen include crescentic, fimbriated, septate, cribriform, and microperforate forms.
It is proposed that an imperforate hymen is formed during fetal development when the sinovaginal bulbs fail to canalize with the rest of the vagina. This result is a solid membrane interposed between the proximal uterovaginal tract and the introitus.
The exact cause of imperforate hymen is not known.
Imperforate hymen may result from failure of apoptosis due to a genetically transmitted signal, or it may be related to an inappropriate hormonal milieu.
Familial inheritance in successive generations has been described
Imperforate hymen is the most frequent cause of vaginal outflow obstruction, occurring in 0.1 % of infant girls.
This vaginal outlet obstruction results in the entrapment of vaginal and uterine secretions under the influence of maternal estrogens and this becomes evident when the distensible membrane bulges between the labia.
In adolescence, the retained secretions consist of menstrual products, and the resulting mass effect in the vagina and uterus are referred to as hematocolpos and hematometrocolpos, respectively.
Pyocolpos (infection of a hydrocolpos) may result from an infection that is ascending through microperforations in the hymen membrane.
Clinical presentations of imperforate hymen in newborns include:
An incidental finding on routine physical examination of a newborn.
The neonate with imperforate hymen typically presents with a bulging membrane between the labia.
The membrane may be white or yellow-grey because it is distended from trapped mucoid material secreted as a result of stimulation by maternal estrogen (Figs. 30.2 and 30.3).
Figs. 30.2 and 30.3
Clinical photographs showing a newborn with imperforate hymen. Note the whitish bulging hymenal membrane
In severe cases, the distention extends proximally into the uterus (hydrometrocolpos).
A lower abdominal midline mass may be evident on physical examination because the shallow pelvis of a neonate allows the uterus to be palpated above the pubis symphysis.
Hydrocolpos can lead to urinary tract infections or bladder obstruction and acute urinary retention.
Asymptomatic imperforate hymen should not be confused with labial adhesions (fused labia) (Fig. 30.4)
A clinical photograph showing labial adhesions (fused labia) not to be confused with imperforate hymen
The diagnosis is made clinically and can be confirmed by ultrasonography.
The treatment is hymenotomy in those with evidence of obstruction or urinary symptoms.
Others advocate observation throughout childhood, with a planned hymenotomy after the onset of puberty.
If a patient is diagnosed with an asymptomatic imperforate hymen in infancy or childhood beyond the neonatal period, the optimal time for surgical repair is after the onset of puberty and prior to menarche.
30.3 Vaginal Atresia
This is a birth defect where the vagina is blocked off to varying degrees.
It is often associated with syndromes such as:
Mayer-Rokitansky-Küstner-Hauser (MRKH) syndrome
Mayer-Rokitansky-Küstner-Hauser (MRKH) syndrome: This syndrome is characterized by the followings:
A deformed or absent vagina
Normal external genitalia.
Vaginal atresia is estimated to occur in 1 in 5,000–10,000 live female births.
Vaginal atresia is a congenital developmental defect resulting in uterovaginal outflow obstruction which can present either:
In the neonatal period with hydrocolpos as a result of accumulation of secretions from the normal cervical glands under the influence of maternal hormones. Extension of fluid accumulation to involve the uterus will result in hydrometrocolpos.
Hydrocolpos can be complicated by infection leading to pyocolpos.
In adolescence with hematocolpos as a result of obstruction to the normal menstrual flow or with primary amenorrhea. Vaginal atresia is reported to be the second most common cause of primary amenorrhea.
Vaginal atresia is classified anatomically into three types:
Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome
Proximal vaginal atresia
Distal vaginal atresia
30.5 Associated Anomalies
Vagina atresia and agenesis are congenital anomalies of the female genitourinary tract and may occur as:
An isolated developmental defect
Part of a complex of developmental anomalies such as:
The Rokitansky-Mayer-Küster-Hauser (RMKH) syndrome
The Bardet-Biedl syndrome
The Kaufman-McKusick syndrome
The Fraser syndrome
The Winters syndrome.
Occur in 30 % of patients with RMKH syndrome.
These anomalies include:
Unilateral agenesis of the kidney
Crossed-fused renal ectopia
Anomalies of the ribs and limbs
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Normally there are two pairs of ducts in the embryo, the wollfian and Mullerian ducts.
These are responsible for the development of the male (Wollfian) and female (Mullerian) internal genitalia.
In the female embryo:
The absence of testes which secret testesterone and Mullerian inhibiting substance (MIS) allow development and differentiation of the müllerian duct system and regression of the wolffian ducts.
The müllerian duct elongate and reaches the urogenital sinus by 9 weeks’ gestation, and form the uterovaginal canal.
The two müllerian ducts proceed caudad to cephalad and fuse together to form the uterine cavity and upper two thirds of the vagina.
The fallopian tubes are formed from the cephalic remnants of the müllerian duct.
The sinovaginal bulbs form as bilateral endodermal invaginations.
Cephalic growth of the sinovaginal bulb and their fusion with the vaginal cord forms the vaginal plate.
Canalization of the uterovaginal canal is believed to occur from the caudal to the cephalic aspect, with an epithelial lining derived from the urogenital sinus.
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