Anorectal Malformations
Also known as . . . imperforate anus, covered anus, ectopic anus
What is it?
During early development of a baby in the womb, the urinary tract, the
reproductive tract and the digestive tract all exit the pelvis through a common opening.
Normally, separation of these structures occurs. In females there is complete separation
of the three systems so that the urinary tract opening is farthest forward (the urethra),
the reproductive tract exits in the middle (the vagina) and the digestive tract exits
farthest back (the anus). In males the urinary tract and the reproductive tract exit
through a single opening (the male urethra) in front, while the digestive tract exits
through the anus. An anorectal malformation is a condition in which the rectum fails to
separate properly during development and does not migrate into its proper position on the
perineum. The anus and rectum lie in front of their normal location and are not located
properly in the sphincter muscles of the pelvis. Anorectal malformations occur as a
spectrum of abnormalities that ranges from very mild conditions in which the anus is
situated only a few millimeters in front of its normal location, to severe anomalies with
no visible anus. In the more severe abnormalities, there may be an abnormal emptying of
rectum into the genitourinary tract, and associated malformations of the spine, genitalia,
and kidneys.
Diagnosis and treatment
Anorectal malformations occur in both boys and girls. The diagnosis of
an anorectal malformation can usually be made by inspection. When the baby is examined,
the anus is absent or abnormally positioned. Ultrasound and x-ray tests may be used to
help in the diagnosis. Additional tests will be obtained to look for associated
abnormalities. Spine x-rays, kidney and spinal cord ultrasound, and occasionally
echocardiography are all routine tests obtained in patients with anorectal malformations.
The nature and severity of the anorectal malformation, as well as the
presence of any associated conditions will determine the surgical treatment that is
required. Some patients may be treated with a single operation as a newborn, while others
will require operations in several stages. For patients with relatively minor
abnormalities, a small procedure such as a cut back anoplasty may be all that is
required prior to going home. For other patients, initial treatment consists of a
colostomy and reconstruction is performed at a later date. A second operation is performed
that separates the abnormal communication with the genito-urinary tract, and properly
relocates the rectum within the sphincter muscles in the pelvis. Depending on the type of
abnormality present, children may have this operation performed utilizing minimally
invasive surgical techniques. Alternatively, a PSARP (posterior saggital
anorectoplasty)
procedure may be performed. Several months after definitive surgery, the colostomy is
taken down, re-establishing gastrointestinal tract continuity.
Following reconstruction, patients born with anorectal malformations
must be followed frequently by their pediatric surgeons. For the more severe
abnormalities, long-term continence issues are the major reasons for follow-up, while in
the more mild conditions, patients and their families must work to insure that worsening
constipation does not lead to poor continence. Many patients must be managed with bowel
program designed to promote regular evacuations of the rectum to avoid ongoing soiling
from chronic fecal retention. With attentive management, and rigorous compliance with
prescribed regimens, most patients achieve social continence. Many patients will have
normal continence. The Pediatric Surgeons at Penn State Children’s Hospital treat
patients with anorectal malformations and provide long-term follow-up and management for
patients and their families. We have a support group called The AnoRectal MalformationS
network (A.R.M.S.).
Glossary of Terms
Ectopic anus: a type of anorectal malformation where the anus is slightly anterior to
(in front of) its normal position
PSARP: posterior saggital anorectoplasty (pronounced
"pee-sarp"), a method of surgically correcting anorectal malformations
Fecal retention: the failure to completely evacuate/empty the rectum on
a regular basis; this term is used in contrast to constipation, since many patients with
fecal retention chronically pass small amounts of soft or liquid stool around a large,
retained fecal mass
Normal continence: regular, voluntary passage of a bowel movement that
completely empties the rectum without accidents or soiling.
Social continence: regular, complete emptying of the rectum using a
bowel program so that fecal retention, soiling and accidents are avoided
Physician's Who Treat Anorectal Malformations
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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