4. Epidemiology
• Incidence – 2.2 per 100,000 live births
• M : F = 2.3 : 1
• Risk in offspring of patients – 1 in 70 live births (500
times greater risk)
• Associated anomalies in families – Mid-line defects –
– Neural Tube defects
– Cleft lip & Cleft palate
5. Risk Factors
• Maternal Age – mean 34y
• Maternal 1st trimester Smoking
• Progesterone (large dose) in 1st trimester
• IVF – 7-10 fold increased risk
• Genetic – CASPR3 gene on Chr.-9, Desmin, p63
• Familial – risk of recurrence in a family → 1 in 100
6. EMBRYOLOGY
• Error (not arrest) in embryogenesis of cloacal membrane
1. Cloacal membrane (CM)– bilaminar layer at caudal end
2. Mesenchymal Ingrowth – infraumbilical abdominal wall
muscles & pelvic bones
3. Urorectal Septum – divided cloaca into UGS & Rectum
4. Genital Tubercles – Medial migration & cephalad fusion
• Failure of mesodermal ingrowth of cloacal membrane
7.
8. THEORIES
• Marshall & Muecke (1968) – Abnormal overdevelopment
of CM during 4th week of gestation → prevents medial
migration of mesenchymal tissue
• Failure of lateral body wall fold to meet in midline
• Abnormal fusion of genital hillocks, caudal to CM
• Abnormal caudal insertion of body stalk → failure of
mesenchymal interposition in midline
11. Rotational Anomalies
10° Coronal rotation of the Sacroiliac joints
15° Inferior rotation of the bony pelvis
Rotational anomalies → Short, Pendular Penis
Waddling Gait
12. Pelvic Floor Defects
• Levator ani muscles
– Posterior displacement – 70% behind rectum (normal 50%)
– 15° outward rotation & 30° more flattened
– No decrease in length / thickness of muscles
13. Abdominal Wall Defects
• Triangular defect from umbilicus to intrasymphysael
band, occupied by exstrophied bladder & post. urethra
• Anterior Rectus Sheath fans behind bladder neck &
inserts on intrasymphysael band
• Umbilicus lower
• Indirect Inguinal hernia – M(80%) > F(10%)
• Umbilical hernia (small); Omphalocele (rare)
14. Anorectal Defects
• Anus displaced anteriorly.
• Colorectal anomalies – 1.8% incidence
– Imperforate Anus – most common
– Rectal Stenosis
– Rectal Prolapse
• Divergent levator ani & puborectalis –
– Anal Incontinence
– Rectal Prolapse
15. Male Genital Defects
• Anterior corporeal length 50% shorter
• 30% greater diameter of anterior coporeal segment
• Prostate not circumferentially around urethra –
Urethra anterior to prostate
• Vas, ED, Seminal vesicles – normal
• Flat, wide scrotum
• Undescended testes
16.
17.
18. Female Genital Defects
• Vagina shorter, but of normal caliber
• Vaginal orifice stenotic & displaced anteriorly
• Labia, mons pubis, & clitoris are divergent
19. Urinary Defects
• No e/o bladder muscle dysinnervation – potential for
normal development after closure
• Bladder polyps – Fibrotic or Edematous – associated
with squamous metaplasia in 50%
• Cystitis glandularis – Risk of Adenocarcinoma (8% in
augmented bladders)
• VUR in 100% closed exstrophy – altered course of
distal ureter with loss of oblique entry
20. Variant Anatomy
• Pseudoexstrophy – classic musculoskeletal defects
with no major urinary defect
• Superior Vesical Fissure – CM rupture in upper part
• Covered Exstrophy – Split-symphysis variant – may
contain sequestered ectopic bowel segment
• Duplicate Exstrophy – Antero-posterior bladder
duplication → one bladder exstrophied & one inside.
23. EPISPADIAS
• Rare as an isolated anomaly
• M (1 in Lakh) > F (1 in 5 Lakh)
1. Complete/Penopubic/Subsymphyseal – 70% case
Incontinence
Deficient UV junction – VUR
2. Penile
3. Glanular
• Short pendular penis with dorsal chordee
