The reproductive system or genital system is a system of sex organs within an organism involved in producing offspring. In men, the genital system includes the prostate, testes, and penis. In women, it includes the ovaries, fallopian tubes, uterus, and vagina. A basic understanding of the embryology of the reproductive tract is essential to restore reproductive and sexual functioning and normalize genital anatomy whenever possible.

The vagina is the elastic, muscular part of the female genital tract, which extends from the vulva to the cervix. In humans, the vagina receives sperms during sexual intercourse, is the channel for the birth canal during the birth process, and also functions as an excretory channel for menstrual flow. Congenital vaginal agenesis is a rare malformation estimated to occur among 1 in 4,000–5,000 female births. The McIndoe technique was first described in 1938 by Bainster and McIndoe as a surgical procedure that improves quality of life and sexual satisfaction and provides a functional vagina with minimal complications for most patients with vaginal agenesis. Congenital and acquired genital anomalies in the adolescent population may lead to difficulties in carrying a pregnancy to term, infertility, and recurrent pregnancy loss, which lead to a great amount of social inhibition and psychological distress for the affected individuals. Such abnormalities are a challenging group of conditions for the reproductive surgeon and need surgical experience and skill. They also require a basic knowledge of the embryology of the reproductive tract to increase the success of diagnostic evaluations and surgical approaches to the region. Accordingly, the aim of this study was to evaluate congenital uterovaginal abnormalities, and their embryogenesis, surgical management, and clinical implications.

Between 1980 and 2015, 8 patients with congenital uterovaginal malformation were diagnosed in our clinics.

An unusual Mullerian duct anomaly, uterus bicornis (double uterus) acollis (absence of cervix), was successfully corrected by uteroplasty and a new cervix was constructed. Complete vaginal agenesis in 7 patients was corrected by a modified McIndoe vaginoplasty technique. Clinical examination performed postoperatively revealed a neovagina of adequate length and caliber. None of the 7 patients had any significant post-operative complications.

The genital system is concerned with the maintenance and propagation of the species. In women, the internal genitalia include ovaries, fallopian tubes, the uterus, and the vagina; the external genitalia include mons pubis, labia majora and minora, the clitoris, the vestibule, and the perineum. Gonads initially develop in females (ovaries) and males (testes) from the undifferentiated genital ridge at approximately the 5th week of development, and gonadal differentiation becomes apparent at approximately the 7th week of embryonic life. In embryos of both sexes, the primitive sex ducts are indifferent and consist of 2 paired ducts—mesonephric (Wolffian) and paramesonephric (Mullerian). With the development of the testis from the genital ridge, the mesonephric duct is retained in males as the duct system of the testis and the paramesonephric duct mostly degenerates. In females, however, the paramesonephric duct plays an important role in the development of reproductive organs and the mesonephric duct and its tubules mostly regress.

At first, these paired bilateral Mullerian ducts pass caudally (through the cranial vertical part), lateral to the mesonephric duct. In the pelvis, they cross (through the intermediate horizontal part) ventral to the mesonephric duct and grow medially. During the 8th week, they reach the caudal end of the mesonephric duct and to contact and fuse with their counterparts (caudal vertical part) to form a Y shaped uterovaginal bulb or tubercle that bulges into the dorsal of the urogenital sinus. Caudal vertical parts of both Mullerian ducts fuse in the caudo-cranial direction, which normally occurs between the 6th and 11th weeks of gestation. The partition between them completely disappears and forms a single duct uterovaginal canal by the end of 3rd month. The cranial part of the utero-vaginal canal forms the entire uterus, and points of fusion of the 2 ducts represent the site of the future fundus. The cranial vertical parts and most of the intermediate horizontal parts of each Mullerian duct form the respective fallopian tubes. Any disruption of Mullerian duct development and fusion during embryogenesis can result in a broad and complex spectrum of congenital abnormalities, termed Mullerian duct anomalies. A uterus is absent in 2% to 7% of patients with vaginal agenesis [1]. Congenital anomalies of the uterus result from varying degrees of failure of fusion of the Mullerian ducts but may occasionally arise from true duplication of the ducts [2]. The incidence reported in the literature ranges between 0.13–0.4% among the general population [3,4]. Unilateral suppression of Mullerian ducts results in an unicornuate uterus, which is unique among Mullerian abnormalities and is the rarest of the uterine abnormalities, accounting for 0.3–4% of uterine abnormalities [5]. Simón et al. [6] also reported that approximately 3.2 percent of fertile women have a bicornuate uterus. In our study (caseI), a unique case of an unusual Mullerian duct anomaly, horseshoe shaped uterus bicornis (double uterus) acollis (absence of cervix) along agenesis of the vagina was noted. This type of abnormality may be due to failure of Mullerian duct fusion in the caudo-cranial direction. To the best of our knowledge, such a unique and unusual Mullerian duct anomaly observed in this study has not been cited in modern literature.

The upper four-fifth of the vagina above the hymen develops from the lower part of the utero-vaginal canal and the lower one fifth develops below the hymen from the ectoderm of the genital folds. The vagina opens into the exterior through the vestibule, which is derived from the ectoderm of genital folds after the rupture of the urogenital membrane. Vaginal agenesis (absence of the vagina) is one of the most significant congenital anomalies of the female reproductive tract from a physical and psychological perspective. Vaginal agenesis is estimated to occur in 1 in 4,000–5,000 live female births. The purpose of vaginal agenesis treatment and appropriate management is not only to create an adequate passageway for penetration but also to facilitate satisfactory sexual intercourse and normalize genital anatomy where possible, and to alleviate her psychological concerns. To treat vaginal agenesis, the McIndoe technique is the preferred method for vaginal reconstruction, and several authors have documented satisfactory sexual relationships using the McIndoe method in over 75% of patients [7]. Mayer-Rokitansky-Kuster Hauser syndrome is a congenital malformation characterized by the failure of the Mullerian duct to develop, resulting vaginal agenesis and absence or hypoplasia of the uterus. Ovaries are normal in the majority of cases, which are more frequently associated with renal and vertebral malformations. Vaginal agenesis is associated with malformations in the urinary tract in 17–56% of patients [8-10]. In our study, urinary tract malformations were absent. Buss and Lee [11] reported an 80–90% graft take in 94% of their patients. Complete graft take 10 days postoperatively was described by Garcia and Jones [12] in 73% of their patients, with an 80–90% graft take in a further 20% of patients. The degree of failure of graft take was not recorded in our present study.

The sex-determining region Y (SRY) gene is located on the short arm of the Y chromosome. During the 6th week of male fetal development, the SRY gene provides instructions for making a protein called the SRY protein (testis determining factor) that influences the development of male phenotypes, such as testes from the genital ridges at the medial posterior abdominal cavity. Complete androgen insensitivity syndrome (testicular feminization) is a syndrome when a male, genetically XY, because of various abnormalities of the X chromosome, is resistant to the actions of androgen hormones, which in turn stops the forming of the male genitalia and gives a female phenotype. This syndrome occurs in one out of 20,000 live births and can be incomplete (various sexual ambiguities) or complete (the person appears to be a woman).Testicular feminization, or androgen insensitivity, is a rare syndrome that is characterized by primary amenorrhea, a 46, XY karyotype, a female phenotype, and the presence of testes rather than ovaries [13-15]. Patients have a congenital resistance to the effects of androgens, which results in an absence of Wolffian duct derivatives and the development of a female phenotype. However, production of the Mullerian inhibitory factor persists, which accounts for the complete regression of the Mullerian duct system. Therefore, patients with testicular feminization have no uterus or fallopian tubes and are without the upper third of the vagina [16]. In approximately one third of these individuals undescended testes have a well-recognized propensity for tumoral proliferation, and the risk of gonadal malignancies increases with age. Hence, it is essential that all women with primary amenorrhea should undergo a complete investigation of the genital tract and endocrine system quickly and accurately to allow clinical and psychologic input.

In conclusion, the findings suggested that a modified McIndoe vaginoplasty technique is a simple, effective procedure for the treatment of vaginal agenesis. We believe that the present study has provided some important data that will contribute to the scientific literature, providing the data of embryogenesis, surgical management, and clinical implications of uterovaginal congenital abnormalities. Awareness of the rare congenital abnormalities noted in our study is essential for surgeons, clinical anatomists, radiologists, and morphologists to increase the success of reproductive diagnostic evaluation and surgical approaches to the region.