Pediatric Imperforate Hymen

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 (see the image below).[6]

The imperforate hymen is a solid membrane interposed between the proximal uterovaginal tract and the introitus. Ambroise Paré first described this condition in 1633.[7] It is classified as a vertical fusion defect. However, it differs from other vertical fusion defects in that it is not derived from the müllerian system. The configuration and normal size of the hymenal orifice in prepubertal girls has received attention in the context of evaluating potential child abuse.[8]

Anatomic variations of the patent hymen exist, with the most common being an anular 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. In some patients, perforations do not become confluent, and a cribriform pattern with multiple small perforations may be observed.[9]

Vaginal abnormalities in the premenarchal patient include hymenal and vaginal cysts, urethral prolapse, labial agglutination, vaginitis, foreign bodies, and lichen sclerosis.

Any obstruction of the vaginal tract during the antenatal, perinatal, or adolescent period results in the entrapment of vaginal and uterine secretions. In patients with imperforate hymen, this obstruction is at the level of the introitus and becomes evident when the distensible membrane bulges between the labia. Various terms, such as mucocolpos, hematocolpos, and pyocolpos, are used to describe this condition, depending on the nature of the retained contents.

In fetal development and in the immediate perinatal period, mucoid secretions from the uterovaginal tract result in mucocolpos under the influence of maternal estrogens. When the diagnosis is made in adolescence, the retained secretions consist of menstrual products, and the resulting mass effects in the vagina and uterus are referred to as hematocolpos and hematometrocolpos, respectively. Reflux of the endometrial tissue through the fallopian tubes (ie, hematosalpinx) may result in secondary endometriosis.

An accumulation of infected material within the vaginal cavity (ie, pyocolpos) may result from an infection that is ascending through microperforations in the membrane.

Specific etiologies for the failure to establish patency are not evident. The cause may be related to 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.[10]

Imperforate hymen is the most frequent cause of vaginal outflow obstruction, occurring in 0.05-0.1% of infant girls.[1]

Outcome after repair of imperforate hymen is excellent. If findings on an appropriate preoperative evaluation are normal, a patient can be reassured that her genital tract is otherwise normal. The incidence of dyspareunia is also low.

Clinical presentations of imperforate hymen range from an incidental finding on physical examination of an asymptomatic patient to findings discovered on an evaluation for primary amenorrhea or abdominal or back pain.[11, 12, 13]

Neonate

Careful evaluation of the perineum of the newborn is essential. Under the influence of maternal estrogens, the female neonate typically has full labia majora. Inspection of the introitus reveals that the hymenal membrane is pink and slightly edematous. The edges of the hymenal membrane may even appear fimbriated.

In the newborn with an imperforate hymen, the membrane is often bulging between the labia because of retained mucoid secretions (see the image below). The membrane may be white because it is distended from trapped mucoid material secreted as a result of stimulation by maternal estrogen. One must distinguish imperforate hymen from a vaginal cyst, which fills the introitus but is attached to only one vaginal aspect.

In severe cases, the distention is in the distal vaginal tract and extends proximally into the uterus. 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. This mucocolpos can lead to urinary tract infections or bladder obstruction. The fact that most patients with imperforate hymen present during early adolescence suggests that the diagnosis is often overlooked during neonatal examination.

Prepubertal child

In the prepubertal child, an imperforate hymen can be mistakenly diagnosed as labial agglutination or a congenitally absent vagina. Differentiation on gross physical examination is often difficult because of the lack of estrogenization of the perineum.

Placing the patient in the knee-chest position aids physical examination in this age group. Have the patient kneel on the examination table with her elbows on the table and her face resting in her hands. Gently spread the buttocks and labia and have the patient exhale or blow.[14] If the examination is still difficult, sedation or anesthesia may be necessary. If an abnormality is suspected, rectal examination or ultrasonography (US) may help in making the proper diagnosis.

Adolescent

The most common clinical presentation includes primary amenorrhea. The adolescent with imperforate hymen typically presents with symptoms of lower abdominal or pelvic pain that may initially be cyclical. A thorough history should be obtained, and the patient and family should be questioned about the patient's abdominal or pelvic pain, with particular reference to the following:

• Cyclical pain
• History of vaginal bleeding (which suggests secondary amenorrhea)
• Family history of genitourinary abnormalities, including imperforate hymen
• Other factors that may help determine if any underlying endocrinologic problem is present

During questioning, the patient and family usually recognize a cyclic pattern to the patient's abdominal symptoms.

When an adolescent presents with primary amenorrhea, careful physical examination is essential. The presence or absence of secondary sexual characteristics should be noted. In the symptomatic female adolescent, genital examination typically reveals a bulging bluish membrane across the vaginal vestibule, which represents the hematocolpos (ie, menstrual products retained in the vagina). If bulging is not noted in the resting state, it may be elicited by having the patient perform a Valsalva maneuver.

Additional presenting symptoms

Additional presenting symptoms of imperforate hymen include back pain, urinary retention[15] (37-60% of patients), and constipation.[16] Urinary retention may be so severe, even in infants, that it can lead to bilateral hydronephrosis[17] or life-threatening renal failure.[18] Although cyclic lower abdominal pain is most frequently reported as the presenting symptom in young women, back pain and urinary retention have also prompted evaluation and resolved after hymenotomy.

Careful physical examination combined with imaging is usually sufficient to establish the diagnosis of imperforate hymen. In certain circumstances related to the child's age and maturity, examination may have to be deferred until it can be performed with the patient under anesthesia.

Laboratory studies are not necessary in the evaluation and treatment of imperforate hymen. Tumor markers CA-125 and CA-19-9 are elevated in imperforate hymen; although these markers suggest the presence of a benign condition, they are not necessary for diagnosis.[21]

The diagnosis should not be confirmed by aspirating secretions beyond the obstruction, because this procedure may result in iatrogenic pyocolpos. Instead, the diagnosis should be confirmed by performing noninvasive imaging studies (eg, ultrasonography [US] or magnetic resonance imaging [MRI]) to determine the extent of the vaginal outflow obstruction and to diagnose other associated anomalies.

Abdominal and pelvic US and MRI are the cornerstones of imaging for uterovaginal anomalies. US provides a reliable means for rapidly diagnosing hematocolpos or hematometrocolpos (see the images below).[22, 23]  If a complex anomaly is suspected, MRI is necessary. In addition, transrectal US may help in delineating complex anatomy. MRI and US also aid in excluding associated congenital anomalies of the urinary tract. Although rare, combined anomalies (ie, imperforate hymen with a transverse vaginal septum) can occur.[24]

Invasive examination is typically unnecessary for diagnosis. However, sedation or general anesthesia may considerably aid in the examination of anxious patients, especially young children. In the optimal situation, the use of anesthesia should be delayed until noninvasive studies are completed and until a surgeon is prepared to proceed with definitive therapy.

Laparoscopy has been recommended in some cases to evacuate pelvic and intra-abdominal endometrial material generated because of retrograde menstruation. This procedure is speculated to reduce the potential for secondary endometriosis. However, most cases of endometriosis regress spontaneously after resection of the obstructing membrane. Most cases do not require concurrent laparoscopy.

Medical therapy has no role in the management of imperforate hymen, because the retained secretions are typically sterile. In addition, the hymen must be surgically resected to relieve the obstruction.

Surgical intervention is most often required in the adolescent who presents with symptomatic vaginal outflow obstruction. Establishing a patent hymen is necessary to eliminate pain and discomfort and to establish a functional genital tract. Avoidance of persistent obstruction preserves the patient's fertility by reducing the risk of secondary endometriosis.

In the infant with a bulging hymenal membrane due to the effects of maternal estrogen, the diagnosis is evident, and surgical therapy can be undertaken promptly.

On occasion, the diagnosis is made serendipitously in asymptomatic premenarchal girls. Intervention can justifiably be delayed until they approach menarche. This delay ensures that a previously nonvisualized orifice, such as an anterior crescentic opening, is absent. The presence of such an opening may obviate surgical intervention.

Surgical intervention is contraindicated only when the evaluating physician is unfamiliar with the condition and the differential diagnoses and when imaging modalities that help in excluding complicated anomalies of vaginal development are unavailable. Because evacuation of hematocolpos rarely requires emergency intervention, referral to a tertiary care center should be considered.

Office CO2 laser therapy has been studied as a means of treating imperforate hymen. In an observational study (N = 49) assessing this approach for managing various benign pathologies and congenital malformations of the female lower genital tract, Frega et al reported rapid, excellent healing among the 13 patients with imperforate hymen, with no wound infection, scarring, stenosis, recurrence, or need for reintervention.[25]

Surgical intervention for imperforate hymen should require only one definitive procedure to evacuate the retained secretions and to ensure the maintenance of patency. Simple drainage of the material confined beyond the hymen is contraindicated, because it does not allow for adequate drainage of the thick fluid, is not definitive, and increases the risk of infection (pyometras).[4]

Two techniques are most commonly advocated: simple incision and small excision of the membrane. Simple incision of the hymen may be associated with postoperative stenosis with strictures, and it is not the method generally preferred at many centers. Use of an X-shaped incision ought to be the method of choice.

An elliptical excision of the membrane is performed close to the hymenal ring, using a needle-tip cautery, followed by evacuation of the obstructed material. This technique is considered to be most effective in definitive treatment. Avoid compressing the uterus and fallopian tubes to speed evacuation of the trapped contents after the hymen is incised.

Procedural details

After the appropriate diagnostic studies are performed, an outpatient procedure to be performed under general anesthesia is scheduled.

Distinguishing an imperforate hymen from a transverse vaginal septum is important because the latter requires a relatively extensive procedure to reconstruct a functional vaginal tract and because it has implications in terms of reduced fertility. The clinical and radiologic distinctions between the conditions are based on the presence of a thin distal membrane in an imperforate hymen versus a thick proximal septum in a transverse vaginal septum. Transverse vaginal septum cannot be treated with a cruciate incision, and imperforate hymen does not require a procedure more extensive than hymenotomy. In contrast to imperforate hymen, transverse vaginal septum poses some concern about future pregnancy outcomes.

The retained secretions are typically sterile unless previous manipulation (eg, needle aspiration) has resulted in infection. Therefore, prophylactic antibiotics are not usually required.

The urethra should be identified first, and a catheter can be placed if the patient has had urinary obstructive symptoms. Various ways of making the incision have been discussed. The incision on the hymenal membrane can be made with a scalpel or with an electrocautery. After the hymenal edges are inspected, the incision is completed, and excess tissue can be resected further, if necessary. To prevent recurrence, absorbable suture is used to perform formal marsupialization by anchoring the incised membrane to the vaginal wall in several locations. Local anesthetic can be injected into the edges of the hymen to achieve postoperative analgesia. As an alternative, lidocaine jelly can be applied topically.

For postoperative analgesia, acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are usually sufficient. The patient should anticipate the continued evacuation of retained material for a week. Uterine or vaginal cramping should also be anticipated and treated with NSAIDs. No further radiologic or surgical evaluation is necessary after a normal menstrual cycle is established.

Incomplete drainage and failure of marsupialization may result in recurrent obstruction and, potentially, an ascending pelvic infection.[26] Although prophylactic antibiotics are not recommended, postoperative fever or abdominal pain must be evaluated and treated promptly. Potential complications include endometritis, salpingitis, or tubo-ovarian abscess—any of which can affect subsequent fertility.

Concern for secondary endometriosis resulting from retrograde menstruation is sufficient for some authors to advocate irrigation of the peritoneal cavity by using a laparoscopic technique. No definitive information regarding the frequency of this condition is available, and most surgeons and gynecologists avoid a concomitant intra-abdominal procedure.

Compared with primary endometriosis, secondary endometriosis generally does not become a chronic condition that impairs fertility. Endometriosis is not a uniformly chronic consequence of hematometrocolpos secondary to imperforate hymen. Retrograde menstruation can occur with secondary endometriosis as a result of vaginal outflow obstruction. However, this condition is believed to be self-limited after the primary condition is corrected.

Postoperative follow-up is deferred for 6-8 weeks to allow the patient to reestablish a menstrual cycle. Findings on evaluation of the patient's menstrual cycle determine the need for further evaluation.