Hypertrophic Pyloric Stenosis

Hypertrophic Pyloric Stenosis is a disorder of GI System in infants.

1. Kelly, a 6-month old infant, has been vomiting whenever she is fed. Her parents thought that she is just overfed, but this has continued for 2 weeks already. They also noticed an olive-shaped mass whenever her abdomen is gently palpated. They consulted at their local pediatrician. What may be the problem?

2. Hypertrophic Pyloric Stenosis Presented by- N/ Cdt P. Soorya Suresh Guided by- Maj Kavita Rajwar

3. INTRODUCTION Pyloric stenosis, also known as infantile hypertrophic pyloric stenosis (IHPS), is the most common cause of intestinal obstruction in infancy.

4. Anatomy

5. DEFINITION Hypertrophic pyloric stenosis is the marked or progressive overgrowth or enlargement of circular muscle fibers of pylorus causing partial or total obstruction of the stomach outlet due to narrowing of the lumen.

6. EPIDEMIOLOGY Occurs in 1-3 per 1,000 infants. More common in whites of Northern Europe, less in blacks and rare in Asians. Males (especially first borns ) are affected approximately 4-6 times as compared to females. 20% of male child and 10% of female child of affected mother develops pyloric stenosis. Increased incidence is seen in blood groups B and O Monozygotic twins are more affected than the dizygotic twins.

7. ETIOLOGY AND PATHOPHYSIOLOGY Exact cause is unknown. Initially thought to be a congenital condition, but it is an acquired condition. Risk factors for development of Hypertrophic Pyloric Stenosis- Erythromycin exposure in neonates with highest risk if medication is given within the first 2wks of life.

8. Female infants of mothers treated with macrolide antibiotics ( e.g ,. Azithromycin ) during pregnancy and breastfeeding. Abnormal muscle innervation Increased serum prostglandin level ETIOLOGY AND PATHOPHYSIOLOGY (Contd..)

9. Decreased level of neuronal nitric oxide synthase Decreased expression of neuronal nitric oxide synthase exon 1c regulatory region Affects expression of neuronal nitric oxide synthase gene Decreased nitric oxide levels Development of Hypertrophic Pyloric Stenosis. ETIOLOGY AND PATHOPHYSIOLOGY (Contd..)

10. CLINICAL MANIFESTATIONS Vomiting Non bilious May or may not be projectile Immediately after feeding May occur after each feeds or may be intermittent Starts after 3 wks of age but can develop as soon as 1 wk or as late as 5 months After vomiting infant is hungry and wants to feed again. Leads to progressive loss of fluids, H+ and Cl - hypochloremic metabolic alkalosis.

11. CLINICAL MANIFESTATIONS Hyperbilirubinemia Most common clinical association also known as icteropyloric syndrome Unconjugated > conjugated hyperbilirubinemia ; corrects by surgery Associated with decreased levels of glucuronyl transferase (5% of patients) due to mutation in bilirubin uridine diphosphate glucuronosyl - transferase gene (UGT1A1)

12. CLINICAL MANIFESTATIONS Pyloric Mass Firm Movable Approximately 2cm Olive shaped Best palpated from left side Located above and to the right of the umbilicus in midepigastrium beneath the liver’s edge Easily palpated after vomiting

13. CLINICAL MANIFESTATIONS Visible gastric peristalsis after feeding

14. DIAGNOSIS History & physical examination Clinical findings USG (criteria for diagnosis) Pyloric- thickness 3-4cm length 15-17cm diameter- >13cm Contrast studies- String sign- -elongated pyloric channel Shoulder sign- -bulge of pyloric muscle into antrum Double tract sign- -parallel streaks of barium seen in narrow channel

15. RADIOGRAPHIC FEATURES Plain radiograph Abdominal x-ray findings are non-specific but may show a distended stomach with minimal distal intestinal bowel gas.

16. 2) Fluoroscopy An UGI (barium meal) excludes other, more serious causes of pathology, but the findings of an upper gastrointestinal series infer, rather than directly visualize, the hypertrophied muscle.  On upper gastrointestinal fluoroscopy: delayed gastric emptying peristaltic waves ( caterpillar sign )  elongated  pylorus with a narrow lumen ( string sign ) which may appear duplicated due to puckering of the mucosa ( double-track sign ) the pylorus indents the contrast-filled antrum ( shoulder sign ) and ( tit sign ) or base of the duodenal bulb ( mushroom sign ) the entrance to the pylorus may be beak-shaped ( beak sign ) RADIOGRAPHIC FEATURES ( contd …)

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

18. RADIOGRAPHIC FEATURES ( contd …) 3) Ultrasound Ultrasound is the modality of choice Advantages over a barium meal are- it directly visualizes the pyloric muscle, does not use ionizing radiation. Disadvantages- it is incapable of excluding other diagnoses such as midgut volvulus . The hypertrophied muscle is hypoechoic , and the central mucosa is hyperechoic . Diagnostic measurements include: pyloric muscle thickness (diameter of a single muscular wall on a transverse image): >3 mm length: >15-17 mm pyloric volume: >1.5 cm 3 pyloric transverse diameter: >13 mm

19. DIFFERENTIAL DIAGNOSIS GERD with/ without hiatal hernia. Adrenal insufficiency from adreno -genital syndrome can stimulate pyloric stenosis. – absence of metabolic acidosis – increased serum K+ – urinary Na+ concentration of adrenal insufficiency Inborn errors of metabolism can cause recurrent episodes of emesis with alkalosis( urea cycle) or acidosis( organic acidemia ) & lethargy, coma, seizures.

20. DIFFERENTIAL DIAGNOSIS (CONTD…) Pyloric membrane/ pyloric duplication -projectile vomiting -visible peristalsis and -palpable mass Duodenal stenosis proximal to ampulla of Vater Clinical features of HPS Differentiate by physical examination or USG (absence of mass). In duplication

21. COMPLICATIONS Post-op complications include- infections fluid-electrolyte imbalances persistent obstruction duodenal perforation

22. PROGNOSIS Prognosis is excellent, unless diagnosis is delayed and prolonged severe dehydration occurs. Mortality rare is after pyloromytomy .

23. MANAGEMENT

24. PREOPERATIVE MANAGEMENT Correcting imbalances of- Fluid Acid-base Electrolyes Correction of alkalosis is essential to prevent post operative apnea due to anesthesia

25. SURGICAL MANAGEMENT Ramstedt’s Pyloromytomy Through a short transverse skin incision Underlying pyloric mass is cut longitudinally to the layer of submucosa Incision is closed

26. Laparoscopic pyloromyotomy Equally successful Shorter time to full feeding, discharge & great parental satisfaction. Success depends on surgeon’s skills SURGICAL MANAGEMENT (contd..)

27. Post- op vomiting occurs in half of the infants; maybe because of edema at the incision in the pylorus. Feedings can be started in 12-24 hrs after surgery Persistent vomiting indicates incomplete surgery, gastritis, GERD or any other obstruction Endoscopic balloon dilation is done for incomplete pyloromyotomy SURGICAL MANAGEMENT (contd..)

28. CONSERVATIVE MANAGEMENT Nasoduodenal feedings in patients who aren’t good candidates for surgery Oral & IV atropine sulphate (pyloric muscle relaxant); 80% success rate. IV atropine Dose- 0.01 mg/kg 6 times a day 5min before feeding Monitor HR & ECG Oral feeding- Started at a volume of 10ml, 6 times/day Volume is increased until patient tolerates 150ml/kg/day unless vomiting occurs > 2 times/day. When feeds are tolerated without vomiting not more than 2 times/day; 0.02mg/kg oral atropine is started before feeding.

29. NURSING MANAGEMENT Pre-Op: Maintenance of fluid & electrolyte along with nutritional intake of breastfeeding (if not contraindicated). Relief of parental anxiety Nasogastric aspiration of gastric distension for vomiting relief. During feeding, baby should be on upright position, slightly towards right. Small; frequent feedings Prevention of HAI Continuous monitoring Vitals, hydration, body weight, vomiting, stool, urine, signs of compications . Parental involvement in care of the baby.

30. NURSING MANAGEMENT (contd..) II. Post-Op : Basic anesthesia care and post-op care to be provided with warmth, feeding, wound care, medications, hygienic care, emotional support to the parents and health education with discharge advice and follow-up. Special attention on oral feeds, usually after 8-12 hrs of surgery, small frequent feeds with EBM. Initially, feedings can be started in a stepwise manner with 1-2 tsp of clear solution (5% glucose) q12hrly for 8 hrs, after anesthesia effect. After feeding, baby should be placed in an upright position towards the right for 45-60 min. Usually discharged on 3 rd -4 th post-op day.

31. Thank you