This document provides information on infantile hypertrophic pyloric stenosis (IHPS). It summarizes that IHPS is a condition characterized by hypertrophy of the pyloric muscle which causes gastric outlet obstruction. It most commonly affects young infants, especially males. Surgical pyloromyotomy is the treatment of choice and has excellent outcomes when performed after resuscitation from dehydration caused by projectile vomiting from gastric outlet obstruction.

1. INFANTILEHYPERTROPHIC
PYLORICSTENOSIS

2. INTRODUCTION
⚫A condition characterised
by hypertrophy of the two
circular muscle layers of
the pylorus.
⚫Resulting in constriction
and obstruction of gastric
outlet.
⚫Described by
Hirschprung in 1888

3. EPIDEMIOLOGY AND ETIOLOGY
 INCIDENCE - 1.5 to 4 per 1000 live births
 EPIDEMIOLOGY - Male : female ratio = 4:1
Increased risk in first born boys
 ETIOLOGY
 IDIOPATHIC
 GENETIC-11q14-22 and Xq23
 Rarely autosomal dominant
 FAMILIAL
 ETHNIC ORIGIN (more in whites): more commonly seen in
Caucasians
 ENVIRONMENTAL

 Erythromycin or azithromycin exposure
Transpyloric feeding of premature babies

4. ETIOLOGY (contd.)
EMERGING NEW THEORIES
GI hormones like gastrin, substance P (could produce chronic
pylorospasm and stenosis) , Epidermal growth factor, deficiency
of NO (can induce muscle spasm preventing smooth muscle
relaxation in stomach).
 Muscle layer deficient in
 quantity of nerve terminals
 markers for nerve supporting cells
 peptide containing nerve fibres

This abnormal innervation of muscular layer
leads to failure of relaxation of pyloric muscle,
increased synthesis of growth factors

5. Associations
⚫Turner syndrome
⚫Tracheo-oesophageal
fistula
⚫Oesophageal atresia
⚫Trisomy18

6. PATHOPHYSIOLOGY
⚫Hypertrophied muscles
⚫Gastric outlet
obstruction
⚫Non bilious projectile
vomiting
⚫Gastric fluid loss
⚫Hypochloraemic
hypokalaemic alkalosis
⚫Paradoxical aciduria

7. PATHOPHYSIOLOGY contd
Vomiting
•Loss of water -----> DEHYDRATION
• Loss of gastric acid from stomach
(HYPOCHLORAEMIA) -----> Impairment
of kidney’s ability to excrete bicarbonate
ion ----> prevents correction of alkalosis
HYPOVOLAEMIA Secondary
Hyperaldosteronism
Acts on kidneys

8. PATHOPHYSIOLOGY contd
• Retains Na+ to correct intravascular volume depletion
•Excretes increased amount of K+ in urine
---->HYPOKALAEMIA ----> hypomagnesemia and hypocalcemia
•Excretion of H+ leading to aciduria
Body’s compensatory response to metabolic alkalosis is
HYPOVENTILATION ---> increased arterial pCO2
(SECONDARY RESPIRATORY ACIDOSIS)
Initial alkalotic urine becomes acidic - PARADOXICAL
ACIDURIA

9. CLINICAL PRESENTATION
 ONSET at 2 to 8 weeks of age
(commonly at around one
month of age)
 SYMPTOMS
 Projectile ,forcible,
frequent episodes of non-
bilious coffee ground
vomiting 30 to 60
minutes after feeding.
 Weight loss
 Persistent hunger
 Lethargy
 Constipation or
hunger diarrhoea

10. CLINICAL PRESENTATION(contd)
SIGNS
 Palpable,olive shaped,
mobile, smooth, firm
mass (1.5 to 2 cm) with
all borders well made
out, moves with
respiration, with
impaired resonance on
percussion to right of
epigastric area.(95%
cases)

11. CLINICAL PRESENTATION(contd)
SIGNS (contd.)
 Visible gastric peristalsis from left upper
quadrant to epigastrium (golf ball waves)
Signs of dehydration
 Jaundice (2%) (due to decreased hepatic
glucuronosyl transferase associated with
starvation)

12. DIAGNOSIS
⚫ ABDOMEN X RAY (erect
posture)
upper abdominal gas bubble in
the stomach.

⚫ ABDOMINAL
ULTRASONOGRAPHY
(Gold standard at present)
Doughnut sign or cervical
pyloric sign
pyloric muscle thickeness >4
mm
 pyloric length >16mm
 in presence of functional
gastric outlet obstruction

13. DIAGNOSIS (contd.)
⚫ BARIUM MEAL/ Fluoroscopy
Peristaltic waves (caterpillar sign)
Delayed gastric emptying
Elongated and narrow pyloric canal-
String sign / Railroad track sign
The pylorus indents the contrast-filled antrum
(shoulder sign) or base of the duodenal bulb
(mushroom sign)

14. The barium may
outline crowded
mucosal folds as
parallel lines - DOUBLE
TRACT SIGN
Bulge in the distal
antrum with streak of
barium pointing towards
pyloric canal- BEAK SIGN
Double tract sign Beak sign

16. DIAGNOSIS ( contd.)
 BIOCHEMICAL CHANGES
 Dehydration
 Malnutrition
 Hypochloraemic hypokalaemic metabolic alkalosis
 Paradoxical aciduria
 Hyperbilirubinemia
ARTERIAL BLOOD GAS ANALYSIS
 Low serum levels of potassium and chloride
 Increased blood pH and high blood bicarbonate level

17. MANAGEMENT
⚫Medical but not a surgical emergency
⚫RESUSCITATION
⚫MEDICAL TREATMENT –
Atropine methyl nitrate orally is tried to relax the
pylorus muscle.

18. PRE OPERATIVE PREPARATION
⚫Resuscitation with IV rehydration.
⚫Correct hypovolaemia with 10 ml/kg 0.9 % saline.
⚫Correct hypochloraemic alkalosis and
hypokalaemia (over 24-48 hrs): 0.45% NaCl in 5%
dextrose with added KCl at a rate of 120-150
mL/kg/24hr.
⚫Nasogastric tube drainage to prevent aspiration of
vomited secretions.

19. Surgery should take place
when:
⚫Dehydration corrected
⚫Normal serum Na and K
⚫Chloride ion >90mmol/l
⚫Bicarbonate ion < 28
mmol/l

20. Surgery
⚫FREDET-RAMSTEDT’s PYLOROMYOTOMY>>>
conventional open procedure
⚫LAPARASCOPIC PYLOROMYOTOMY>
⚫DOUBLE –Y PYLOROMYOTOMY>

21. PYLOROMYOTOMY
FREDET-RAMSTEDT’s
PYLOROMYOTOMY
 Division of pyloric muscle fibres
without opening of bowel lumen.
 Done via right upper quadrant
incision or laparoscopically.
 Caution not to open mucosa and
avoid the prepyloric vein of Mayo.

22. LAPARASCOPIC
PYLOROMYOTOMY
⚫ Effective alternative
⚫ Time to achieve full enteral feeding is significantly
shorter ( 18.5hrs) in those treated laparoscopically
vs those having open pyloromyotomy(23.9 hrs)
⚫ Better cosmesis

23. A, Laparoscopic
pyloromyotomy is
started using a
retractable blade.
B, A spreader with
grooves on the outer
surface is used to
complete the
pyloromyotomy. Intact
mucosal bulging along
with independent
muscular wall motion is
confirmed.

24. DOUBLE –Y PYLOROMYOTOMY
⚫Has also been safely and effectively performed .

25. ⚫The double-Y pyloromyotomy (Alayet's pyloromyotomy)
seems to be a good technique for the surgical
management of IHPS.
⚫It offered a better functional outcome in terms of
postoperative vomiting during the first postoperative
week and weight gain during the first 10 days in our
initial series while having a safety profile similar to
Ramstedt's pyloromyotomy.

26. POST OPERATIVE CARE
⚫Patient started on feedings of glucose and water or an
electrolyte infant formula ( eg - pedialyte) 4-6 hrs after
surgery.
Gradual increase in oral fluids till feeds are accepted
without emesis. Full feedings reached after 24 hrs from
surgery.
⚫Antibiotic prophylaxis not required.
⚫Postoperative monitoring for 12 hrs required in patients
with
 Hypoglycemia
 Hypothermia
 Respiratory depression and apnoea(due to CSF alkalosis and
intraoperative hyperventilation)

27. COMPLICATIONS
 Duodenal perforation – may go undetected especially in
laparoscopic RAMSTEDT’s.
 Continued postoperative bleeding
 Persistent vomiting (due to incomplete pyloromyotomy )
dehydration, weight loss and severe electrolyte imbalance .
If persists >1 week, redo surgery.
 Foveolarcell hyperplasia (FCH), a rare cause of persistent
gastric outlet obstruction.(This requires an extended
pyloromyotomy) .

28. PROGNOSIS
⚫Excellent unless diagnosis is delayed and
prolonged severe dehydration occurs.
⚫Once adequately treated, pyloric stenosis does
not recur.
⚫Mortality is rare after pyloromyotomy.

29. Thank You