7.1 Introduction

Congenital Müllerian anomalies occur in approximately 5% of females. Patients with simple anomalies may be asymptomatic and diagnosed incidentally during investigations for other gynaecological problems or in pregnancy. Others can present in a number of different ways and at different ages depending on the type of anomaly. The most common presentations include primary amenorrhoea, obstructed menstruation, dysmenorrhoea, dyspareunia, difficulty with tampons, infertility and recurrent miscarriage.

Clinical assessment, pelvic ultrasound and magnetic resonance imaging are all useful for investigating anomalies of the Müllerian tract. Trans-vaginal ultrasound is less useful in adolescent girls who may never have been sexually active or may not have a vagina. In these cases and also for more complex anomalies requiring detailed preoperative planning, magnetic resonance imaging (MRI) should be used. This has been found to correlate very well with clinical findings when assessing Müllerian and vaginal anomalies.

Complex Müllerian anomalies should be discussed in a multidisciplinary team comprising specialist gynaecologists, urologists, clinical nurse specialists, radiologists and psychologists. This is an NHS England recommendation for congenital gynaecological anomalies.

There are various different classification systems for Müllerian anomalies, with the most widely used being the American Society of Reproductive Medicine classification [1]. However, this classification system does not describe the vaginal anomalies well. The European Society of Human Reproduction and Embryology (ESHRE) and the European Society for Gynaecological Endoscopy (ESGE) have developed a newer classification system for Müllerian anomalies [Reference Grimbizis, Gordts, Di Spiezio Sardo, Brucker, De Angelis and Gergolet2]. This categorises anomalies based on the anatomical variation with uterine, cervical and vaginal anomalies having independent subgroups.

Müllerian anomalies are frequently associated with renal malformations due to their common embryological development and imaging of the renal tract should be performed in all cases.

7.2 Embryology

An understanding of the development of the Müllerian duct is essential for the diagnosis and management of Müllerian anomalies. Undifferentiated ducts (Müllerian and Wollfian) begin to develop during the sixth week of embryonic development. In the absence of an SRY gene and therefore no anti-Müllerian hormone, the Müllerian ducts continue to develop caudally and medially with midline fusion to create the fallopian tubes, uterus, cervix and upper vagina.

The urogenital sinus forms by week 7. Cells proliferate from the upper portion of the urogenital sinus to form structures called the sinovaginal bulbs. These fuse to form the vaginal plate, which extends from the Müllerian ducts to the urogenital sinus. This plate begins to canalise, starting at the hymen and proceeding upwards to the cervix. This process is complete by 21 weeks of gestation.

7.3 Imperforate Hymen

The hymen is a thin membrane which separates the vaginal lumen from the cavity of the urogenital sinus until late fetal life. It usually becomes perforate before or shortly after birth. The incidence of imperforate hymen is approximately 1:1000 live female births. Classic presentation is that of increasing cyclical pain in the absence of menstruation in adolescence. On clinical examination, there may be a palpable pelvic mass per abdomen or on ultrasound scan. On gently parting the labia, there may be a visible bulging membrane, with a bluish coloration due to the presence of blood in the vagina. Treatment is with incision, drainage of haematocolpos and resection of the hymen. If the hymen is not resected, there is a risk of re-obstruction. However, care must be taken not to resect too close to the vaginal mucosa, which may lead to scarring and stenosis at the vaginal introitus. Vaginal dilation is not usually required and long-term reproductive outcomes are good. Imperforate hymen are not associated with any other Müllerian duct or renal tract anomalies. See Figure 7.1.

Figure 7.1 Imperforate hymen.

7.4 Transverse Vaginal Septum

Transverse vaginal septae (TVS) are a rare type of Müllerian anomaly. The exact incidence is unknown but may be between 1:2100 and 1:72,000 [Reference Williams, Nakhal, Hall-Craggs, Wood, Cutner and Pattison3]. They are thought to result from a failure of canalisation of the vaginal plate at the point where the urogenital sinus meets the Müllerian duct. Septa can be perforate or imperforate and vary in their thickness and location in the vagina. Imperforate septa present in adolescence with obstructed menstruation and haematocolpos. Girls with a perforate septum often have normal menses and usually present with difficulties with intercourse or tampons.

Transverse vaginal septa are classified according to their location in the vagina (low<3 cm from introitus, mid 3–6 cm, high >6 cm), thickness, and presence or absence of a perforation. Accurate classification using clinical examination, USS and MRI is imperative for planning treatment. Treatment involves surgical resection of the septum with anastomosis of the proximal and distal vaginas. It is important that the entire septum is resected to prevent vaginal stenosis and subsequent dyspareunia. Septa can be resected vaginally, laparoscopically or via an abdomino-perineal approach depending on the classification of the septum [Reference Williams, Nakhal, Hall-Craggs, Wood, Cutner and Pattison3].

Thin (<1 cm) perforate septa can be operated on vaginally, with low complication rates and good long-term reproductive outcomes. Occasionally, rotation of perineal skin flaps is required to bridge the vaginal defect and ensure a normal calibre vagina. Septa that are mid or high and <2 cm thick with an adequately distended proximal vagina and no other complex pelvic anomalies are suitable for laparoscopic resection [Reference Williams, Cutner and Creighton4]. These have also been shown to have low complication rates and good long-term reproductive outcomes. More complex septa (>2 cm thick, imperforate septae) will require an abdomino-perineal approach, due to the possibility that a bowel segment may be required to bridge the gap between the proximal and distal vaginas. Skin grafts have also been used for this purpose, but these are often unsuccessful when there is scarring from previous surgery, and there is a risk of scarring and vaginal stenosis in the donor region. More recently buccal mucosa has also been used to bridge the gap between the proximal and distal vaginas. Abdomino-perineal vaginoplasties often involve complex reconstructive surgery and therefore long-term complications such as re-obstruction and fistulae are more common [Reference Williams, Nakhal, Hall-Craggs, Wood, Cutner and Pattison3].

Vaginal dilation is recommended following all laparoscopic and abdomino-perineal vaginoplasties, and where rotational skin flaps are used in vaginal resection. This helps to maintain vaginal capacity and prevent stenosis or re-obstruction, although there is little evidence-base to support this. See Figure 7.2.

Figure 7.2 MRI of transverse vaginal septum with large haematocolpos and haematometra.

7.5 Longitudinal Vaginal Septum

Longitudinal vaginal septa result from a failure of canalisation of the vaginal plate during embryogenesis. Septa can be complete, extending from the cervix to the introitus, or they can be partial involving any part of the vagina. They often present with dyspareunia or difficulty inserting tampons, or they may even be diagnosed during labour. Occasionally, one hemivagina may be obstructed resulting in regular menstruation with a history of gradually worsening pelvic pain, secondary to obstructed menstruation. Examination may reveal a unilateral vaginal wall swelling secondary to haematocolpos. MRI is the imaging modality of choice for these anomalies. In the majority of cases, there is an associated uterine anomaly, most commonly a complete uterine septum or uterus didelphys. Obstructed hemivaginas can be associated with renal anomalies on the same side as the obstruction, as in the OHVIRA (obstructed hemivagina and ipsilateral renal anomaly) syndrome.

Treatment usually involves surgical resection of the septum if the girl is symptomatic. The entire septum must be excised to avoid dyspareunia. This can be performed vaginally, with low complication rates and good long-term outcomes. Care must be taken with haemostasis due to the vascular nature of the vagina. Dilation is rarely required following surgical resection. Obstructed hemivaginas can be surgically more challenging, and therefore should be managed in a centre with expertise in operating on such anomalies.