Urogenital Devt N Anomalies

DEVELOPMENT OF THE UROGENITAL SYTEM AND MALFORMATIONS - Dr Kabare • PREVIEW Embryo has three layers

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Endoderm - forms the lining of primitive gut, part of the urinary apparatus Ectoderm – covers the outer surface of the embryo. Some of the lower genital tract. Mesoderm – muscles, skeleton connective tissues, vascular systems, major portions of the urogenital system.

URINARY SYSTEM

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The first precursor of urogenital system appears at 3 weeks. Cells sprout from the nephrogenic cord to form the pronephros. These cells further unite to form the pronephric (wolffian) duct. The duct Lumen establishes connection with hindgut lumen and this area dilates to form the cloaca. Pronephros is rudimentary and non functional and quickly disappear. The pronephric duct persists and is used by the second excretory organ, it becomes the mesonephric duct. Mesonephric stage: As pronephros disappears nephrogenic cord divides into cell masses; which becomes vesicles which form the cellular membrane of mesonephric glomeruli. Mesonephric duct forms the ureteric bud which gives origin to distal ureter. The major portion of genital system in the male is of mesonephric duct. In the female the mesonephric duct makes pathway for paramesonephric ducts which form most of the genenital tract mucosa. Mesenchyme around the mesonephric duct proliferates to form the urogenital ridges. At maturity each mesonephric unit has a functional glomerulus and a tubule which empty into the mesonephric duct METANEPHROS (Permanent Kidney): The mesonephros regresses cranial caudally and is replaced by metanephros. This appears on the fifth week, same time as the gonads. Collecting ducts. Ureteric bud forms on the caudal part of mesonephric duct. It gives rise to; collecting tubules, calices renal pelvis and ureter. The expanded tip of the bud becomes the ampulla which subdivides and eventually makes 12-15 generations of collecting tibules. Dilation of the tubular branches produce renal pelvis, major and minor calices. Middle generations form the medullary collecting tibules.

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Nephrons: Ureteric bud cranially grows into the dorsal end of the nephrogenenic cord, thus the bud gets into contact with the metanephric blastema.

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Blastema becomes cap – like structure over the ampullated end of the bud. Blastema cells are influenced by the ampulla to form cell clusters which elogate and differentiate into metanephric tubules. Mid portion of

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the tubules produce proximal and distal convoluted tubules. Central – mid portion forms the loop of henle The cup shaped end of the metanephric tubule becomes the Bowman’s capsule. Its invaginated by a tuft of capillaries forming the glomerulus. Formation of urine is thought to begin at 10-13 weeks when 20% of nephrous are morphologically mature. There are positional changes of the kidney due to 90o medial rotation of the kidney. Midline structures growth and differential growth of the lumbosacral area and reduction of curvature of the embryo

CONGENITAL ANOMALIES OF THE FEMALE GENITALIA • Most developmental defects of the perineum, vulva and vagina are discovered when premenarchal child is examined. • Those of the uterus, tubes and ovaries are rarely found before menarche. THE VULVA • Position variations, contour size and texture. • Vulva detrousse – deeply set vulva between bulging sides of perineum associated with narrow pubic arch and a narrow perineal body. Firm perineal muscles and more than normal hair growth on thighs, body and arms • Duplication of the vulva – very rare more an indication of imperfect twining. Also associated with two vaginal and uterus. • Labia – Hypertrophy – commonest occurrence of both labia minor and majora in most cases no treatment is necessary. • Ambiguous genitalia – occur in congenital adrenacortical hyperplasia female and male pseudohermaphroditism etc. • They reveal – enlargement of the phallus labio – scrotal folds and hypospadic urethra emptying into the urogenital sinus. CLITORIS • Hypertrophy variable sizes • Splitting or cleavage of clitoris. Usually a part of a major abnormality consisting of extrophy of the bladder hyposperdia or splitting of urethra. Anterior portion of labia majora are widely separated and pubic hair when it appears on mons pubic is abscent on the midline. • Agenesis of the clitoris is very rare

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Caudal Appendage - Tail like caudal appendage – rare

PROLAPSE OF UTERUS AND VAGINA Extremely rare condition and associated with lack of development of perineal floor. ANOMALITIES OF CLOACAL DIVISION Ano-rectal malformations: • Imperforate anus • Fistula – urorectal communications

ANOMALIES OF THE URETHRA BLADDER AND URETER • Epispadias • Hypospadias – associated – incontinence of urine • Urethral duplication – complete, partial CONGENITAL ANOMALIES OF URETHRAL STRUCTURES • Relatively Common • Most of them at the external meatus obstruction of the urethra causes distortion of the urinary tract above § UTI § Hydro – ureter § Hydronephrosis •

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discomfort. Inspection of vulva – bulging dome – shaped tense hymenal membrane • May have: o Hematocolpos o Hematometra o Tubes may be involved also DDx:

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Symptoms – difficult in urinating, bacturia, enuresis, dribbling incontinence, frequent terminal haematuria, abdominal or flank pain. Extreme – loss of renal function

1. Congenital Urethral Contratures - Occurs at 2. 3. 4.

vesicourethral juncture, may have serious consequence if untreated. Congenital Urethral Cysts. Congenital Urethral Diverticulum Extrophy of the bladder

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ANOMALIES OF THE URACHUS This may present as umbilicovesical fistula or urachal cyst. Rx is surgical excision URETERAL ECTOPY Position anomalies of ureteral orifices may be formed urogenital cleft, urethra, vagina, cervix, uterus, it can be one cause of urine incontinence. ANOMALIES OF THE HYMEN • Anterior displacement • Hymenal septum. Thick median septum creating two orifices may have possibility of septate vagina and duplication of internal genitalia. • Cribriform hymen – may lead to frequent vaginities. • Almost imperforate hymen • Imperforate hymen • Large hymenal orifice Imperforate hymen • This may produce mucocolpos in infancy and hematocolpos when the girl starts to menstruate. • The imperforate hymen is thought to be a remnant of urogenital membrane. Imperforate hymen results when mesoderm of primitive streak abnormality invades the urogenital portion of the cloacal membrane. Dx: • Infants – may present with abdominal pelvic mass due to mucoid distension of the vagina displacing the small uterus up-wards. • Often diagnosis is made in early adolescence when menstrual flow fails to appear despite recurrent cyclic menstrual symptoms, may also present with urinary difficulties, lower abdominal pain and vaginal

labial adhesion :This rarely occurs at birth. Its as a result of vulva inflammation. The adherent labia hides the introitus and urethra vaginal agenesis • Perineum is not distorted • There is dimpled depression where the introitus should be • The hymen is marked by a rugged or corrugated fold. • Rectal exam – thickened cord of tissue usually palpable when vagina is present is not felt. • Vaginogram – no hollow cavity NOTE: place a 18 gauge hypodermic needle between the urethra and anal opening. A catheter is placed in the urethra and the examiners finger in the rectum guiding the needle. A large vaginal cyst – bulging through the introitus • Cyst does not have grayish white coluor. • Small instrument can be passed on the side of the tumuor into the vagina

ANOMALIES OF VAGINA May result from failure of fusion of paramesonephrric ducts or faulty growth of urogenital sinus. Most of the anomalies of the vagina do not cause symptoms during infancy and childhood. Diagnosis thus can easily be missed till late adolescence. • Double vagina – rare May be confused with septum. In true doubling each vagina has separate mucosa, lumbria propria and muscular coat. Often accompanied by double vulva urethra, bladders and two uteri •

Septate Vagina Occurs because the lower potion of paramesonephric ducts fail to fuse properly thus a longitudinal saggital septum partially or completely divides the vagina. • Often uterus is bicornuate or separate • Cervix usually one in incomplete septum of the vagina opening into each halve of the vagina. DX – Can be coincidental, may have dysparunea especially when septum lies against one side of the vagina or one cavity is much smaller than the other RX – Not required but information is necessary. In most cases one side of the vagina is adequate for normal coitus and delivery

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Transverse vaginal septum Usually due to failure of canalization of the vaginal plate. DX – Due to dysperunia or coincidental gyn exam, Cryptomenorrhea

RX – Vaginal plastic operation to create a vaginal canal adequate for coitus, elective C\S is indicated in such cases. •

Vaginal Hypoplasia Usually associated to other urogenital anomalies opens in the perineum, cloaca – like urogenital sinus or in the urethra.

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Vagina Atresia Complete or partial failure of canalization of vaginal plate. DX made on infant exam at birth or if the uterus has fully formed when menstruation begins, they have symptoms like those of imperforate hymen. RX; surgical approach both via the abdominal and vagina routes

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Vagina Agenesis Failure of proliferation of uterovaginal plate Atresia of the vaginal plate. DX; at birth on examination – no vaginal opening. In most cases there is concomitant aplasia of upper part of the paramesonephric ducts, thus the uterus and uterine tubes are rudimentary. The ovaries are normal (different origin) DDX • Imperforate hymen • Labial adhehesion • Large vaginal cyst • Intersex anamalies RX – In absence of the uterus objective is to create functionally satisfactory coital canal. Congenital vaginal cysts Usually develop from occluded persistent fragments of the mesonephric ducts; from unfused portions of the paramesonephric ducts or obstructed paraurethral ducts. RX – For big ones excision but note injury to urethra bladder, ureter or bowel may occur

UTERINE ANOMALIES Rarely present in childhood. Most of the problem they create is infertility or complications of pregnancy and labour.

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Cervical stenosis – rare

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Atresia of the cervix – Due to failure of development and canalization of the cervical portion of the fused paramesonephric ducts. Its rare . When menstruation begins may cause hematometra

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Hypoplasia of the uterus Lesser degrees are of no consequence Severe hypoplasia – uterus is small cord of tissue, usually without a cavity. Causes 1o amenorrhea but the ovaries may be normal functionary – well developed , thus normal female

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Aplasia of the uterus True aplasia is rare In most cases accompanied by aplasia of the uterine tubes. Vagina agenesis is always present in true uterine aplasia.

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Failure of Paramesonephric duct Fusion § Bicornuate uterus § Arcuate uterus § Partially septate uterus § Unicormate uterus with rudimentary horn § Septate uterus with single cervix § Unicornuate uterus § Complete septate uterus

ANOMALIES OF THE UTERINE TUBES • Important in terms of fertility purposes. • Small supernumerary or accessory tubes attached to the fabriated ends or communicating with the isthumus or ampulla portions. OVARIAN ANOMALIES

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Failure of normal ovarian descent – remains in the fetal position above the pelvic inlet.

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Ovarian Aplasia rare DDX – Undescended testis in a male, gonads are inguinal or external genitalia Torsion, necrosis and resorption rather that of aplasia. May occur

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Accessory Ovaries Forms a third ovary, lie along the path of ovarian descent. Accessory ovarian tissue may exist extraperitoneally.

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Ovarian Hypoplasia Ovary poorly developed due to: • Intersex problem • Rudimentary gonad (turmers) • General endocrine disturbances

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Ovarian Agenesis