An Overview of Cloacal Malformation and UG Sinus

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An Overview of Cloacal Malformation and UG Sinus

• Stephen Confer, MD
• Ben O. Donovan, MD
• Brad Kropp, MD
• Dominic Frimberger, MD
• University of Oklahoma
• Department of Urology
• Section of Pediatric Urology

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Normal GU Development
The mesonephric (Wolffian) duct descends from the
mesonephros to meet the urogenital sinus. Once
this connection is made, fetal urine drains into
the urogenital sinus. The ureteric bud arises
from the mesonephric duct and progresses
laterally to invade the metanephrogenic blastema
(precursor of the mature kidney). The caudal end
of the mesonephric duct (past the ureteric bud is
called the common excretory duct. As renal
development proceeds, the common excretory duct
is incorporated into the urogenital sinus.
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Normal GU Development
Progressive incorporation of the common excretory
duct eventually leads to separate openings of the
ureter and mesonephric duct into the urogenital
sinus. By 37 days of gestation, the ureter
empties into the urogenital sinus cephalad to the
mesonephric duct. The urogenital sinus is divided
between the orifices of these two tubes. The
cephalad portion of the urogential sinus will
become the bladder while the caudal portion will
become the urethra
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UG Sinus

• Persistent UG Sinus with normal anus and rectum
  2 to adrenogenital syndrome
• Genetic female with varying degrees of
  masculinization of lower GU tract 2 excess
  androgens
• Least severe clitoral hypertrophy and
  labio-scrotal fusion
• Severe phallus resemble penis and a high vagina
  that enters close to bladder neck

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UG Sinus
Normal appearing vulva in an infant Retraction of
labia reveals only a single opening
Karyotype 46 XX. 12 years old girl. Penis-like
clitoris.
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Exam

• Inspect perineum
• anal opening in normal to anterior position
• Single opening anterior to rectum
• Clitoromegaly consider adrenogenital syndrome
• External Genitalia masculinized
• penis scrotum
• no palpable gonads
• Important newborn w/o palpable gonads should
  increase suspicion that the patient could be
  female
• Rectal examination may reveal a uterus

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Work Up

• Exam
• Labs
• U/S
• Genitogram
• Cystosccopy

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Surgical Correction

• Determine level where urethra and vagina converge
• Classical Mobilize vagina and urethra separately
• Mobilize entire UG sinus (Pena)

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Low Confluence

• Mobilize entire UG sinus less devascularization
  of vagina
• Vaginoplasty- with posterior perineum flaps
• Urethroplasty /- use UG sinus create
  neobladder, gives appearance of vagina with
  urethra
• Reconstruction of External Genitalia
• Labia minora UG sinus
• Labia majora
• Clitoral reduction

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High Confluence

• Vagina enters above level of external sphincter
• Vagina separated from urethra
• Vaginoplasty- mobilize vagina and create
  perineum flaps
• Urethroplasty use UG Sinus for distal urethra

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Cloacal Anomalies

• 7 mm embryo cloaca common chamber where GI and
  urinary tract converge
• Latin mean sewer
• 22mm urorectal septum divides cloaca into UG
  sinus and rectum
• Persistent cloaca normal in birds and reptiles
• Interruption of differentiation give a wide range
  of abnormalities

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Cloacal Malformation

• 150,00 births
• Bladder, vagina, and rectum converge above the
  perineum
• When convergence is low can have a normal looking
  female with anteriorly placed or imperforate anus
• Conservation of structures at the bladder neck
• Urine can fill vagina and displace bladder
  anteriorly causing obstruction and hydronephrosis
• Obstruction of colon

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Cloacal Malformation

• Cloaca exists when the rectum, vagina and urinary
  tract meet and fuse into a single common channel.
• If the channel is short (lt3cm), well-developed
  sacrum and good sphincters will likely be
  present.
• A longer channel indicates a more complex defect
  with a poor sphincter mechanism and an abnormal
  sacrum

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Cloacal Malformation

• Preoperative photos show a normal appearing
  external genitalia, but no anus. Examination of
  the vaginal introitus reveals a rectal fistula to
  the posterior vaginal fourchette through which a
  catheter was placed for demonstration

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Prenatal Diagnosis

• A fetal ultrasonogram at 27 weeks' gestation the
  most obvious feature is the large cystic
  structure arising from the fetal pelvis. This is
  a dilated vagina (hydrocolpos) which is
  compressing the bladder inferiorly.

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Prenatal Diagnosis

• A maternal MRI scan with intravenous contrast
  medium at 31 weeks' gestation. The larger cystic
  structure seen in the fetal pelvis is a dilated
  vagina (hydrocolpos) filled with fetal urine the
  other cystic structure situated to the right of
  the view is the bladder

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Other Findings

• Sacral bony abnormalities seen on plain films

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Management

• Decompression with right transverse colostomy
• Resist pull through
• Catheterize probably vagina, seldom vesicostomy
  or vaginotomy
• Treat co-morbid condition
• W/U electrolytes, U/S, genitogram, cystoscopy
  MRI (R/O tethered cord)
• Treat urinary tract abnormality first or at the
  same time

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Management

• VUR 84/135
• Colostomy in neonate to releive colon obstruction
• CIC, seldom vesicostomy or vaginotomy
• Definitive repair until 1 y/o
• Pt with double vaginas can have septum incised
  endoscopically

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Surgical Repair

• Position- total body prep alternating position
• Posterior sagittal approach
• Mobilze rectum and pull through
• Mobilize vagina and separate from UG-sinus or
  bladder neck, rotate 90 prevent fistulas, may
  need perineum flaps or bowel interposition
• Mobilize UG Sinus to create neourethra
• Post need CIC, enemas
• Colostomy closure 6 weeks

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Hendron

• 154 pts
• Voiding
• 83 spontaneous
• 40 CIC , 1 continent diverson, 4 UD, 5 wet, 8 too
  early
• Bowel
• 83 move bowels spontaneously
• 38 enema, 9 colostomy, 7 soil, 5 too early
• Coitus 24 adults,
• 14 married, 7 no coitus ( 2 married)
• 6 conception caesarian section

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