Congenital Hypertrophic Pyloric Stenosis

What are the parts of pylorus?

The incisura angularis divides the stomach into a body to the left and a pyloric portion to the right.

The sulcus intermedius further divides the pyloric portion of the stomach: the pyloric vestibule to the left, denoted by an outward convexity of the greater curvature.

The pyloric antrum or pyloric canal to the right

The pyloric antrum is 2.5 cm and terminates in pyloric orifice into duodenum.

 What happens to the normal anatomical structural in CHPS?

In infants with IHPS, the pyloric ring is no longer identifiable as a clearly definable separation between the normally distensible pyloric antrum and the duodenal cap.

Instead, a channel of variable length (1.5–2.0 cm) corresponding to the pyloric canal separates the normally distensible portion of the antrum from the duodenal cap.

·         Infantile hypertrophic pyloric stenosis was first fully described by Harald Hirschsprung in 1888.

·         IHPS VS CHPS - ?????

IHPS is would be a better terminology as various studies have shown that the stenosis develops postnatally with normal pyloric anatomy at birth.

What is the most common age group for Hypertrophic PS ?

3 weeks but can present from 1st week till 5 months (Nelson 21^st e)

What sex is common?

1st born male child have 4-6 times more risk than female.

Preterm infants are more susceptible.

20% male offspring born to mother with HPS develop HPS while 10% of female develop the condition.

Offspring of mother than father with HPS tend to have higher risk of HPS

Which blood groups tend to have HPS?

O and B

What are the other congenital defects associated with HPS?

TEF and hypoplasia or absence of inferior labial frenulum.

Is HPS present at birth?

NO. It probably develops after birth.

Associated conditions ARE:

a.       Eosinophic gastroenteritis

b.      Apert Syndrome

c.       Zellweger Syndrome

d.      Cornelia De Lange

e.       Trisomy 18

f.       Smith-Lemli-Opitz.

          Any gene mutation identified ?

       APOA1(apolipoprotein A1)

 Etiopathogenesis of CHPS

Helicobacter Pylori infection has also been associated with CHPS

High GASTRIN          HIGH GASTRIC ACIDITY        PERSISTANT PYLORIC CONTRACTION

·        Which macrolides are found to be associated with CHPS?

             Erthromycin and azithromycin but not clarithromycin

             Macrolides taken within 2 weeks of life

             Erythromycin intake by mother during pg and breast feeding has been associated with CHPS.

   Are there any data on expression of growth factors in etiology of CHPS?

  Certain studies show a local increase in expression of growth factors IGF-1 and PDEGF in the     muscularis propria of the hypertrophic pyloric muscle in children with IHPS.

·         What is the initial symptom?

             Non billous vomiting which may be non projectile at the beginning and later progress to be project.

        AKA HAPPY VOMITER

        What is the metabolic abnormality associated ?

               Hypokalemia with Hypochloremic metabolic alkalosis and paradoxical aciduria.

·           What is the cause of paradoxical  aciduria ?

What is icteropyloric syndrome?

HPS with unconjugated hyperbilirubinemia which is due to impaired uridinyl glucoronyl transferase.

How to diagnose?

Physical examination

Imaging

·       What is the characteristic finding in the physical examination ?

      Firm mass which is olive shaped palpable in the mid epigastrium below the edge of liver above and to the right of umbilicus and best palpated after vomiting.

      Visible peristalsis After feed.

·         In what percentage of children olive is palpable?

 40 to 90%

·         What are the USG findings ?

             Pyloric thickness of 3-4 mm

        Length of 15-19 mm

             Diameter of 10-14 mm.

        Target sign in transverse view

        

        The USG has sensitivity of 95%

        What are the barium swallow findings?

         String sign ( due to the presence of contrast material in the elongated pyloric antrum)

         Shoulder sign and

                Double tract sign.

·         What is double tract sign?

        This sign demonstrates the intervening redundant mucosa outlined as a filling defect by the contrast        material.

·         What is Caterpillar sign?

        The stomach appears distended, air-filled and with wave-like contours, resembling the appearance of       a  caterpillar.This sign is produced when the gastric hyperperistaltic waves come to an abrupt stop at       the pylorus.

How is the appetite of a child with CHPS?

Voracious

How do we treat HPS?

 IV fluids for hydration

 Dyselectrolytemia

 Surgery

·        What is the surgery?

 Ramstedt pyloromyotomy which includes incision of pylorus till submucosa and suturing the serosa .

Conrad Ramstedt was born in 1867. He was a german surgeon who performed the Ramstedt pyloromyotomy in 1911 and produced various papers on the procedure

·       What is the associated mortality?

O to 0.5%

·       When to start feeds

12-24 hours reaching to full feeds at 36-48 hours

·        What are the causes of persistent vomiting despite Sx?

              Failed Sx.

        GERD

        Eosinophilic Gastroenteritis

       What are the conservative approaches to CHPS when Sx is not possible?

 NJ tube feeding

 IV and Oral atropine sulphate

How to adminster atropine?

 0.01mg/kg per dose 6 times a day before

start feeds at 10ml/feed for 6 times and gradually increase till 150ml/kg/d is reached