Anorectal Malformation.ppt 3n6e2u

Presented By Anu George MSc Nsg(Peadiatrics) Student Supervisor: Dr.(Mrs.) Raman Kalia Lecturer

Imperforate anus Includes agenesis and atresia of the rectum and anus Etiology: unknown Incidence: 1 in 4,500 SEX: 60% male

ARM: Embryology The cloaca

(which is a common chamber into the hindgut and allantois)

Separated into:

The bladder

post-allantoic gut (rectum) Downward growth of a septum

Proctadeum (epiplastic bud)

Fusion during the 3rd month of intrauterine life when there is imperfect fusion

imperforate anus

Imperforate anus Low abnormalities

High abnormalities

Termination of bowel below the pelvic floor

Termination of bowel above the pelvic floor

Easy to Diagnose Simple to R

Often have a fistula into the urinary tract with deficient pelvic floor Difficult to R

Outlook is good 1)Covered anus 2)Ectopic anus 3)Stenosed anus 4)Membranous stenosis

1)Anorectal agenesis 2)Rectal atresia 3)Cloaca

1)Covered anus Anal canal covered by a bar of skin with a track running forwards to the perineal raphe. This track is called “Bucket Handle” midline Raphe fistula.

2)Ectopic anus

Anus situated anteriorly in ♂, it opens in perineum in ♀, it opens in vulva ectopic anus

or vagina

(more commonly)>>

(rare)

vulval

3)Stenosed anus i.e. microscopic anus There is a minute opening that can be seen if examined carefuly

4)Membranous stenosis Rare Anus is

normally sited covered with a thin membrane that bulges with retained meconium

Could be associated with:

a fistulas connection between the blind rectal stump and the bladder or other pelvic structures abnormally

1)Anorectal Agenesis Rare Blind rectal pouch lies just above the pelvic

floor In ♂ anterior aspect attached to the bladder & often there is a rectovesical fistula or rectourethral fistula (manifested by age of gas or meconium in the urine) or perineal fistula In ♀ fistula to the posterior fornix >> rectovestibular (or rectovaginal) low RVF Easy to correct Post-op. Function is good high RVF Difficult to correct Post-op function is poor

2)Rectal atresia Rare Anal canal is normal but ends blindly at the level

of pelvic floor & the rectum also ends blindly above the pelvic floor without a fistulas opening.

3)Cloaca Occurs only in ♀ Bowel, urinary & genital tracts all open into a

common wide cavity Commonly associated with other developmental abnormalities e.g. tracheoesophagial fistula

Approach History >>> the systems involved Examination >>> DDx Investigation >>> Dx Management

History Failure to meconium within the 1st 24

hours of life.

Patients with anterior ectopic anus may

present in childhood or in adulthood. These patients have lifelong histories of constipation and painful defecation and usually have required laxatives or enemas for management.

Examination Inspection alone is sufficient for management plan in 90% of patients. ? Low

•Bucket handle defect •Gas/meconium from perineum •Perineal fistula if skin bridge between vestibule and fistula. •Anterior ectopic anus i.e. normal sized anus surrounded by normal muscle. •Urine free of meconium

(NB average of 20 hrs for meconium to appear in urine).

High

•Flat bottom •Short sacrum •Little muscle contraction •Meconium per urethra •Rectovestibular fistula if within mucosal margin of the vestibule. •Sphincter located close to the scrotum or bifid scrotum often associated with a Prostatic Fistula. •Cloacae are often missed if urethral opening is not identified in female with a “recto-vaginal” fistula. •Furthermore, cloacae often have small openings and may be a cause of referral for ambiguous genitalia.

Investigation Very Important to:

1. Exclude other anomalies!! 2.Determine whether abnormality is high or low!!

1. Exclude other Anomalies!!! Anal atresia may occur as a part of the VACTERL

group of anomalies V Vertebral body segmentation defect A Anal atresia C Cardiovascular (PDA, VSD) TE Tracheo esophagial fistula R unilateral Renal agenesis L Limb anomaly (radial ray hypoplasia)

So, very careful examination of the baby must be made to exclude these anomalies

Exclude other Anomalies!!! (contd…)

Associated abnormality

Investigation

"V" Vertebral Abnormality )butterfly vertebrae, hemi-vertebrae(

Spinal ultrasound, Spinal x-ray

"C" Cardiac, Heart Abnormality Cardiac ECHO )VSD, ASD, PDA(

Cardiac ECHO

"R" Renal, Kidney abnormality )solitary Renal ultrasound, Voiding cystokidney, horse shoe kidney( urethra-gram )VCUG( "TE" tracheoesophogeal abnormality )TEF(

Physical examination

"L" Limb deformity

Physical examination, x-rays

2.Determine whether abnormality is high or low!! 1)Invertogram:

 with a metal button or a coin strapped to the site of the anus or

a metal bougie inserted into the blind anal canal  Infant is held upside down for 3-4 minutes  Then radiograph in the inverted lateral position ( both the greater trochanters should be on the same line)  The gas in the rectum will rise to the top indicates the distance between the site of the metal indicator and the blind end of the rectum >>> if the distance > 2.5 cm, the abnormality is high!!  if the rectum ends above the PC line (pubococcygeal line = from the symphysis pubis to the last vertebra), the abnormality is Low & vise versa or according to ischeal line (between ant.-sup. Iliac spines). When to be done? Although it is a useful method, sometimes vitiated by a plug of meconium in the rectum causing an apparent gap far in excess of that actually present. So, it may be necessary to wait until the baby is 24 hrs old before rectal gas appears

Metal button

PC line gas in the rectum

2)Urine culture: Presence of meconium Presence of proteus or pseudomonas usually signifies that a fistula is present

3)US: To evaluate the lesion type

4)MRI: If we suspected complex malformation

5)Micturating cystourethrogram: By injecting a dye in the urethra

Treatment of Low abnormalities: 1)Covered anus: The track should be opened by scissors Followed by routine dilatation of the anus 2)Ectopic anus: Plastic “cut-back” operation 3)Stenosed anus: Regular dilatation

Treatment of High Abnormalities:

Very difficult problem & each case must be considered on its merits The possibilities are: Two-stage operation: 1st stage laparotomy Division of rectourethral fistula Transverse colostomy 2nd stage rectal “pull-through” operation One-stage operation: laparotomy Division of fistula “pull-through” operation Division of fistula & rectal “pull-down” operation through the perinum ( now rarely used)

Treatment of High abnormalities (contd…) The new technique is post-sagittal anorectoplasty

(PSARP)

Colostomy only ( for cloaca)

Pull-through Operation Lower bowel is mobilized New age is created through the

pelvic floor by ing a pair of curved forceps & through it, keeping close to the urethra, to the site of the future anus. This is dilated by Hegar’s dilator so that the bowel can be pulled down and its mucosa stitched to the skin of the newly formed anus. Daily dilatation will be required for at least 3 months after the operation and it may be necessary for years.

PSARP

The PSARP dissection is along the midline providing excellent exposure with minimal trauma to nerves and musculature. It involves: • Stimulation of muscles to demonstrate the midline and sphincter • Posterior sagittal incision - length depends on severity of abnormality and required extent of dissection • Rectum identified. Abdominal approach may be required in addition in 10% of males and 40% of cloacae • Rectum dissected • Separation from genitourinary tract • Repositioning the neoanus within the sphincteric mechanism

Position for PSARP

Incision in PSARP

Posterior sagittal repair of a rectovestibular fistula.

Prognosis In high % of cases, imperforate anus is associated with other congenital abnormalities especially of the urinary organs & nearly 50% of deaths in cases of imperforate anus are due to other malformations

Nursing Management Identification of ARM at birth and prompt

management/ Referral Prepare for colostomy Demonstrate to the parents the care of colostomy Ensure competent home care and regular follow up Preparation for surgery Post-Op Nursing Management

Nursing Management (contd…) Post-Op Immediate post-op care Prevent Infection and promote healing: Care of

the suture line, antibiotics Nutrition Systematic Dilation Prevention of constipation Bowel training Care of colostomy

In a Summary 1 opening >>> Cloaca 2 openings >>> anorectal agenesis with

rectovaginal fistula 3 openings >>> ectopic anus, stenosed anus, membranous anus, rectal atresia or even normal anus!!! The most important investigation is the invertogram It is very important to rule out other anomalies The best & the newest operation is PSARP

Bibliography 1. Marlow D.R and Redding B.A. Textbook of

Pedatric Nursing. 6th Edition. p: . 2. Donna L Wong. Essentials of Pediatric Nursing. 5th Edition. p: 845-847 3. Kliegman and et al(2007); Nelson Textbook of Pediatrics; 18th edition; pages: 1635-39.

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