pyloric stenosis

1. INFANTILE
HYPERTROPHIC
PYLORIC STENOSIS

2. CASE
28 days old infant with repeated projectile vomiting
Dehydrated
? Tumor felt in right hypochondrium

3. 1.What is it?
Hypertrophy of the smooth muscle of the
pylorus, resulting in the obstruction of
outflow
2. Risk Factors?
Family Hx,firstborn males,decreased
incidence in African-American population.
3. Average Age
Usually from 2 weeks after birth to about 2
months.
CHPS

4. INCIDENCE
2- 4 in 1,000 live births
more commonly in males
30 percent of cases occur in firstborn
genetic predisposition
Sibling has 5 times more incidence
environmental factors
Neonatal hypergastrinemia and gastric
hyperacidity may have a role

5. HISTORICAL PERSPECTIVE
First described by Hirschsprung in 1888
Ramstedt described an operative procedure to alleviate the condition
in 1907 – the procedure used to this day to treat pyloric stenosis

6. ETIOLOGY
Abnormal muscle innervation
Nitric oxide synthetase defect
Neonatal hypergastrinemia
Gastric hyperacidity
Erythromycin
Milk curd theory

8. NORMAL PYLORUS

9. IHPS

10. PATHOLOGY
Thickened and elongated Pyloric channel
Hypertrophied and redundant pyloric mucosa
Gastritis
Decreased nerve cells, NO syntetase activity in the muscle

11. MUCOSAL THICKNESS

12. PATHOPHYSIOLOGY
Failure of pylorus relaxation, Absence, reduction, or delayed maturation of Interstitial
cells of canal ( Intestinal pacemaker)
Increased gastric acid secretion and an increased parietal cell mass with enhanced
release of secretin and cholecystokinin have been described
Prostaglandin E2 was increased in the gastric juice
Increased amounts of insulin-like growth factor, transforming growth factor, platelet
derived growth factor, epidermal growth factor, as well as growth factor receptors in
hypertrophied circular and longitudinal smooth muscle of patients with pyloric
stenosis.
Abnormal innervation of smooth muscle cells of the pylorus in pyloric stenosis.
Recently, interest has been directed at the role of nitric oxide in pyloric stenosis, It
mediates relaxation of smooth muscle,

13. CLINICAL
MANIFESTATIONS
The classic presentation of IHPS is the
three- to six-week-old baby who
develops immediate postprandial,
non-bilious, often projectile
VOMITING and demands to be
re-fed soon afterwards
(a "hungry vomiter").

14. PALPABLE MASS
The mass is most easily felt immediately
after emesis because it may otherwise be
obscured by a distended antrum and/or
tensed abdominal muscles

15. VGP(VISIBLE GASTRIC
PARISTALSIS)
Peristaltic waves may be seen progressing
across the child's upper abdomen from left
to right just before emesis.

16. METABOLIC CHANGES
Repeated vomiting: loss of water, sodium, potassium, chloride, and
hydrogen ions; develops hypochloremic metabolic alkalosis with
hyponatremia and hypokalemia
Sodium Conservation: The urine is initially alkalotic from excreted
bicarbonate, Sodium is mostly reabsorbed in an attempt to maintain
extracellular volume, but there is some obligatory sodium loss
accompanying bicarbonate in the urine, result in paradoxical
aciduria in the presence of a systemic metabolic alkalosis
Metabolic alkalosis from pyloric stenosis can cause hypoventilation
with a resultant hypercapnia.
As dehydration progresses, metabolic acidosis, starvation ketosis,
and possibly hyperkalemia from prerenal failure may be seen

17. METABOLIC CHANGES
Bicarbonate > 29 mEq/l and serum chloride
< 98 mEq/l are considered indicative of
hypochloremic metabolic alkalosis in pyloric
stenosis.
The severity of dehydration and metabolic
alkalosis
□Mild: serum bicarbonate < 32 mEq/l, serum
chloride > 100 mEq/l,
□Moderate: serum bicarbonate 32-42 mEq/l, serum
chloride 90-100 mEq/1,
□Severe: serum bicarbonate > 42 mEq/l, serum
chloride < 90 mEq/l,

18. D/D
GER (Gastroesophageal reflex)
Hiatal hernia
Pylorospasm
Preampulary duodenal obstruction

19. DIAGNOSIS
History collection
Physical examination
ultrasound or upper gastrointestinal (UGI)
contrast study
pyloric muscle length (PML), and pyloric
diameter (PD). Published criteria have ranged
from 3 to 4 mm for PMT, 15 to 19 mm for PML,
and 10 to 14 mm for PD

21. BARIUM STUDIES

24. DOUBLE TRACK SIGN

25. NON-SURGICAL
MANAGEMENT
Balloon catheter dilatation of the stenotic pylorus,
Injection of botulinum toxin,
Antispasmodics to relieve pylorospasm,
Transpyloric nasoduodenal feeding
Atropine:Oral or intravenous atropine has been used
successfully in patients with pyloric stenosis.
Atropine temporarily suppresses spastic
contractions of pyloric muscle in pyloric stenosis,
and it resulted in cessation of vomiting and eventual
regression of pyloric hypertrophy.

26. RAMSTEDT
PYLOROMYOTOMY

27. OPERATIVE TECHNIQUE
Open approach
□Transverse RUQ(right upper quadrant)
incision
□Supraumbilical curvilinear incision with
midline fascial opening
Laparoscopic
□Decreased post-op emesis
□Less post-op pain and analgesic use

28. NURSING MANAGEMENT
The timing of surgery depends upon the clinical status of
the infant. If the diagnosis is made early and the child is
well-hydrated with normal electrolytes, surgery may take
place on the day of diagnosis. Surgery should be delayed
in the setting of dehydration and/or electrolyte
derangements

29. HIGH ANAESTHETIC RISK
Small infant
Metabolic derangements
Full stomach

30. PRE-OP MANAGEMENT
Rehydration:
□May require initial saline bolus
□45% DNS twice the maintanance
□Add potassium 20 meq/L after infant passes urine
□Correction of alkalosis is important: serum chloride of
100 mEq/l and higher generally reflects satisfactory
rehydration,

31. POST-OP MANAGEMENT
Watch for apnea
Intravenous administration of 5% dextrose in 0.25 to 0.45%
NaCl solution at a maintenance rate
Blood sugar levels may be checked intermittently

32. COMPLICATIONS OF
SURGERY
Most frequent complications as GER (11 percent), duodenal
perforation (8 percent), and wound infection (5 percent). The
incidence of wound dehiscence and bleeding is very low .