Development of the vagina
♣Origin:
2 origins: * Upper 3/4 from Mullerian duct.
* Lower 1/4 from urogenital sinus.
◊ When Mullerian tubercle (lower end of Mullerian duct) reaches urogenital sinus,
considerable growth occurs forming vaginal plate (sino-vaginal bulb).
◊ Vaginal plate is solid but undergoes canalization at 18 weeks to form vaginal lumen.
◊ Hymen: * separates Mullerian duct & urogenital sinus.
* consists of vaginal epithelium & urogenital sinus epithelium.
* Later, opening develops to allow escape of menstrual flow.
IV. Development of the vagina
N.B.
◊ Transverse vaginal septum:
Failure of fusion between Mullerian duct & sino-vaginal bulb.
◊ Imperforate hymen:
Failure of canalization of lower end of vaginal plate.
Congenital anomalies:
A. Imperfect development
Vaginal agenesis:
◊ Def.: absence of vagina either completely or partially (upper 3/4 only).
◊ C/P: * Symptoms: lry amenorrhea & delayed menarche.
* Signs : absent vagina.
◊ Investigations:
1) Imaging: *U/S: to confirm presence or absence of the uterus.
*IVP: to exclude renal anomalies.(Common association)
2) Lab.: * testosterone level : to exclude TFS.
*chromosomal analysis: to exclude TFS.
◊ D.D.: other causes of lry amenorrhea.
◊ Treatment:
1. If uterus is present: immediate surgical removal of obstruction to allow
menstrual flow (stent with central opening may be left for 6 weeks).
2. If uterus is absent:
Aim: surgical creation of neovagina to allow satisfactory coitus
Procedures: (BMW)
Baldwin operation: loop of ileum is implanted to be a vagina.
Mc Indoe’s operation:
– Skin graft or Amniotic membrane prepared on a mould is used)
– Steps:*dissect space between bladder & rectum.
*line it with the graft from thigh on a wooden mould.
– Complications: *injury of the rectum.
*implantation dermoid cyst.
William operation:U-shaped incision involving inner
aspects of labia majora & suturing
labia in 2 layers.
B. Imperfect fusion:
1. Transverse vaginal septum
Cause: failure of fusion between MD & urogenital sinus.
Types: Complete: primary amenorrhea, hematocolpos & hematometra.
Incomplete: asymptomatic & may be dyspareunia & dysmenorrhea.
Treatment: removal.
2. Longitudinal vaginal septum
Cause: imperfect fusion between 2 MD.
C/P : Double vagina with dyspareunia.
Treatment: removal of septum (unification of both vaginae).
C. Imperfect canalization:
Imperforate hymen: leads to cryptomenorrhea.
D. Other anomalies:
◊ Congenital vesico-vaginal fistula: very rare.
◊ Congenital recto-vaginal fistula.
◊ Congenital uretro-vaginal fistula.
Development of vulva
♣ Origin:
Furogenital sinus as following.
♣ Stages:
a.Indifferent stage (in both sexes):
◊ 2 thickenings develop on each side of the urogenital membrane:
* Inner genital fold. * Outer genital swelling.
◊ The genital folds meet with each other above urogenital membrane to form
genital tubercle.
b.Differentiation stage: (depend on hormones):
a) Genital Tubercle: clitoris.
b) Genital Swellings: labia majora.
c) Genital Folds : labia minora.
♣ Congenital anomalies:
◊ Congenital dermoid cyst.
◊ Clitoridal cyst.
◊ Congenital hypertrophy of the
clitors or the labia minora.
N.B.
Hymen: Developed at the junction of urogenital sinus & Mullerian duct.
Bartholine gland: Developed as outgrowth from urogenital sinus.