2. Anorectal malformations comprise a wide spectrum of
diseases, which involve the distal anus and rectum as well as
the urinary and genital tracts.
Defects range from the very minor and easily treated with an
excellent functional prognosis, to those that are complex,
difficult to manage, are often associated with other
anomalies, and have a poor functional prognosis.
3. Anorectal malformations occur in approximately 1 : 5000 live
births.
The etiology of such malformations remains unknown and is
likely multifactorial.
Genetic etiology may be a cause
5. EmbryologyDevelopment of Rectum
- The terminal dilated part of the
hindgut distal to allantois is
called cloaca. It is divided into
two parts by urorectal septum:
(a) a broad ventral part called
primitive urogenital sinus and a
narrow dorsal part is called
primitive rectum.
- The urogenital sinus gives rise
to the urinary bladder and
urethra, while the primitive
rectum gives rise to the rectum
and upper part of the anal
canal.
6. The anal canal
develops from two
sources:
(a) hindgut
(endodermal origin)
(b) proctodeum
(Ectodermal origin)
7. Types of ARM
Arm are classified according to
the level of the rectal pouch in
relation to the levator ani
muscle into:
High
Intermediate
Low
others
9. Associated anomalies
VACTERL
vertebral : Predominantly lumbosacral
A – anorectal
C - cardiac : TOF, VSD
T - tracheo
E - esophageal
R – renal: VUR, UDT, Hypospadias
L – limb: Radial ray anomalies
10. Clinical examination
In general, boys with anorectal malformations present with intestinal obstruction
(abd. distension, failure to pass meconium, vomiting) in the newborn period.
Girls present with h/o passing meconium/stools from an abnormal site. (within
the fourchette)
11. Perineum
No opening
Abnormal opening
Anal dimple +/-
Bulge at the site of anus
Buttocks – flat /well developed
Sacral spine – sacral agenesis.
Associated anomalies
12. Management
Resuscitation
N/G tube
IV fluids
Antibiotics
U/S & ECHO
Plain X-Ray in prone lateral position after at least 24 hours
CT scan
MRI
13.
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16.
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18.
19.
20.
21. Surgical treatment
Single stage (Anoplasty)
Multiple stages
Sigmoid colostomy
PSARP
Closure of colostomy
