Congenital Anomalies and Creation of the Neovagina



Congenital Anomalies and Creation of the Neovagina


Cassandra K. Kisby

Assia Stepanian

John B. Gebhart



Introduction

Female genital malformations are common. They are seen in 5.5% to 6.7% of the general population, 7.3% of the females with infertility, and 16.7% of patients with recurrent miscarriages.1,2 This chapter briefly explores the embryology of the female genital system and reviews the diagnosis and management of congenital anomalies, with a focus on vaginal agenesis and creation of the neovagina.


EMBRYOLOGY OF THE FEMALE REPRODUCTIVE TRACT

At birth, the urologic and genital system are functionally separate; however, embryologically, they are interconnected due to their common mesodermal origin. The urogenital system differentiates through complex epithelial-mesenchymal interactions in the presence of promoting or inhibiting factors. Anomalies arise when these processes fail to occur normally. Anomalies of the urogenital system are common and knowledge of the embryologic origins is imperative to understanding the causes and treatments of these conditions.

The cloacal membrane is located on the ventral embryo and becomes partitioned into the urogenital sinus and anorectal canal by the urorectal septum, the eventual perineal body (Fig. 5.1A). The mesonephric ducts attach to the urogenital sinus around the fourth to seventh week of development as the urinary bladder is expanding. A pair of each of the mesonephric (wolffian) and paramesonephric ducts (müllerian) is present in male and female embryos. The paired paramesonephric ducts form the bilateral fallopian tubes and broad ligaments cephalad and fuse to form the uterus, cervix, and upper vagina caudally. In the absence of müllerian inhibiting substance, the mesonephric ducts regress in the female (Fig. 5.1B). The distal vagina forms from the urogenital sinus, from which the sinovaginal bulbs emanate and form the vaginal plate. The vaginal plate canalizes by the fifth month of development to form the vaginal lumen. Given the interconnectedness of the embryologic pathways, error in formation, fusion, or resorption pathways often results in combined congenital anomalies.


CONGENITAL ANOMALIES OF THE FEMALE REPRODUCTIVE TRACT

Müllerian anomalies and malformation of the genitalia can impart significant consequences for sexual function and reproductive potential. The prevalence of female congenital anomalies is estimated to be as high as 5.5% in an unselected population and 24.5% in women who have experienced miscarriage and/or infertility.2 Patients often seek care for primary amenorrhea or for workup of pregnancy loss or infertility; however, many congenital anomalies may go undiagnosed if the patient is asymptomatic.

No one classification system exists for female reproductive tract anomalies given the number of variations and combinations of variations that exist. The American Society of Reproductive Medicine has a naming convention specific to uterine anomalies (Fig. 5.2).3 Dr. Leila Adamyan authored a morphologic-functional classification of müllerian anomalies targeted at creating protocols for treatment and rehabilitation of each class of malformation; the 2014 version contains 10 classes and 25 groups of malformations (Table 5.1).4,5 Common anomalies and syndromes of the female reproductive tract are presented in Table 5.2. The remainder of this chapter focuses on diagnosis and management of vaginal agenesis.


DIAGNOSIS AND WORKUP OF SUSPECTED VAGINAL AGENESIS

Although vaginal agenesis can arise from sex-steroid pathway defects, a majority of cases are of unknown etiology and suspected to result from multifactorial inheritance. The most common clinical presentation of vaginal agenesis is with Mayer-Rokitansky-Küster-Hauser

syndrome (MRKH). The incidence of MRKH is estimated to be 1 per 4,500 to 5,000 female births.6 So as not to make assumptions regarding concomitant anomalies or etiologies, the following sections on workup and management focus generically on absence of the vagina and refer to it as vaginal agenesis.











Patients with vaginal agenesis typically present at the time of puberty for primary amenorrhea or at coitarche due to their inability to have penetrative intercourse. Depending on the presence or absence of the rudimentary uterine horns and functional endometrium, presenting symptoms may also include cyclic abdominal pain due to hematometra of the uterine remnants, which are present in 90% of patients. Concomitant anomalies of the urinary and gastrointestinal tracts are present in 53% of patients and skeletal anomalies in 12%.

The patient presenting with vaginal agenesis is reliant on the physician to guide her, determine the extent of the pathology, offer support and reassurance, and provide guidance on options to achieve penetrative sexual function and, possibly, reproductive potential. It is imperative to have a kind and open discussion with the patient regarding her goals and expectations because these will direct counseling and management. A thorough history should be collected to evaluate the degree of psychological and sexual development, identify prior interventions and additional pathology, guide further investigation, and select the best approach to address the needs of the patient. Surgical histories may reveal neonatal intervention, which may suggest history of more extensive anomalies such as bladder or cloacal exstrophy. Depending on the patient’s comfort, the exam may be performed in the clinic or deferred to the operating room to be conducted under anesthesia. The latter option allows for more complete assessment with cystoscopy, vaginoscopy, and diagnostic
laparoscopy, as appropriate. An exam should include evaluation of the perineum for the presence of a vaginal dimple or pouch. If a pouch is present, the apex may contain a palpable longitudinal band, which represents the rudimentary uterosacral ligament. The uterine remnants and adnexa are often not palpable unless hematometra is present. It is important to distinguish vaginal agenesis from obstructive anomalies such as a distal transverse septum or imperforate hymen, where the patient may present with pain and hematocolpos. To do this, imaging is beneficial. Transperineal and transabdominal imaging may be performed to delineate pelvic anatomy. Alternatively, magnetic resonance imaging may be preferred due to the ability to concurrently assess for uterovaginal, urologic, and spinal anomalies. Figure 5.3 demonstrates common concomitant anomalies found on imaging in patients with vaginal agenesis.









SURGICAL PROCEDURES FOR CREATION OF A NEOVAGINA

After defining the patient’s anatomy, the clinician should, through shared decision-making, decide if penetrative intercourse is a goal and if creation of a neovagina is an appropriate next step. Diagnosis of vaginal agenesis is often distressing and can significantly impact a patient’s self-esteem and future intimacy. Psychological support should be provided and interventions only undertaken when the patient is psychologically ready and willing to participate in the care and maintenance of her neovagina. Finally, management of the uterine remnants should be discussed. Although the majority are rudimentary and nonfunctional, a small number may require menstrual suppression or surgical excision if active endometrium or pain is present.


Nonsurgical Management

The primary and least invasive means to create a neovagina is by use of vaginal dilators. In 1938, Frank7 first described a nonoperative means of creating a neovagina by applying pressure to the vaginal dimple with progressively longer and wider dilators to elongate the vagina. Ingram8 subsequently described a technique of passive dilation by instructing patients to sit on a dilator that had been affixed to a bicycle seat. Dilation should be performed by applying firm pressure (with a slight posterior angle) on the vaginal dimple three times daily for at least 20 minutes. With consistent dilation, anatomic and functional success can be achieved. In a multicenter study of 131 patients, a mean vaginal depth of 9.6 cm was achieved with the dilator method, compared to 11 cm with surgical intervention.9


McIndoe Neovagina

If, following counseling, the patient desires surgical intervention or if she has failed nonsurgical management, she should be presented with options for neovagina creation. The most widely used operation for neovagina creation is the Abbe-Wharton-McIndoe operation, commonly known as the McIndoe operation.10 This method was first described by Wharton, in 1938, as a combination of simple dissection of the vaginal space and maintenance with a form. It was not until later that Sir Archibald McIndoe incorporated a split-thickness graft and achieved excellent success in clinical trials. The McIndoe technique has three main principles:



  • Dissection of the space between the rectum and bladder


  • Inlay of a graft and temporary mold


  • Dilation with dilators and/or intercourse to maintain patency


















Technique of the McIndoe operation (Video 5.1)

With the patient in lithotomy position, a 3- to 4-cm transverse incision is made in the apex of the vaginal pouch, if present. In the absence of a pouch, the transverse incision is made just beneath the urethral meatus. The neovaginal space is then sharply and bluntly dissected cephalad, with the guidance of a finger in the rectum, to the level of the peritoneal reflection (Fig. 5.4). The dissection space should easily accommodate two fingerbreadths. If necessary, the levator muscles can be divided laterally to provide sufficient space. Meticulous hemostasis is then achieved. Next, the foam rubber vaginal form is shaped with scissors (Fig. 5.5A). The form is placed into a sterile condom and compressed. The compressed form is then inserted into the vagina and allowed to expand for 1 to 2 minutes. The distal end of the condom is tied, the form removed, and a second condom is placed over the form and the end tied.

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May 1, 2023 | Posted by in GYNECOLOGY | Comments Off on Congenital Anomalies and Creation of the Neovagina

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