Pyloric Stenosis
Study guide:
Definition:
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Congenital hypertrophy of the pyloric muscles at the end of the stomach causing gastric outlet obstruction.
Epidemiology:
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2-4 per 1000 live births in the US.
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Incidence is 1.4 cases per 10,000 live births according to a study done from
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1990-2008 by Riyadh Military Hospital.
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More common in males with M: F ratio of (5:1).
Etiology:
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Most common cause is idiopathic.
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Other causes:
Pyloric stenosis is the disease of firsts (1st):
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In 1st born child (30%).
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Presents in the 1st month.
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Vomiting is the 1st event to happen after feeding.
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1st thing in management is correcting the electrolyte disturbance.
Environmental:
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Maternal smoking
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Bottle feeding
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Formula milk
Genetic:
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200-fold higher rate among monozygotic twins and a 20-fold increase among dizygotic twins or siblings.
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Associated with Turner and Edwards syndromes.
Others:
Macrolide antibiotic use (erythromycin, and clarithromycin) during the first two weeks of age.
Clinical Presentation:
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The hallmark characteristic is non-bilious projectile vomiting:
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Dehydration, and weight loss.
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Usually present during the first month (3-6 weeks of age):
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But can present late up to 6 month of age.
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Because of vomiting:
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They usually have hypochloremic, hypokalemic metabolic alkalosis.
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During physical exam:
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Succussion splash during Auscultation.
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Olive sign on palpation of the epigastric area.
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Visible gastric peristaltic waves in the left lower quadrant.
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Diagnosis:
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Blood laboratory electrolytes show ↓K+, ↓Cl- with metabolic alklasosis
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Best initial test is abdominal ultrasound:
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Thickening of the pyloric sphincter
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Most accurate diagnostic test is upper GI barium series showing:
Sign
String sign
Picture
Figure 1: Thin column of barium leaking.
Sign
Mushroom (Umbrella) sign
Picture
Figure 3: Impression made by the hypertrophic pylorus against the duodenum.
Sign
Shoulder sign
Picture
Figure 2: Filling defect in the antrum due to inward displacement of the muscle.
Sign
Railroad track sign
Picture
Figure 4:Excess mucosa will lead to formation of two barium columns.
Management:
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Stabilize the patient and assess rehydration (half NS with 5%D and KCl):
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Assess the benefit of immediate fluid restriction.
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Electrolyte replacement.
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NGT to decompress the bowel.
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Surgical pyloromytotomy is the definitive treatment:
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Oral feeding should be restarted after 12-24 hours post surgery.
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References:
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Le, Tao, and Kendall Krause. First Aid For The Basic Sciences. New York: McGraw-Hill Medical, 2012. Print.
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Lissauer, Tom, Graham Clayden, and Alan Craft. Illustrated Textbook Of Paediatrics. Edinburgh: Mosby, 2012. Print.
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Cvetnic, William G, Eduardo Pino, and Christine E Koerner. USMLE Step 2 CK Pediatrics. [New York]: Kaplan, 2011. Print.
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Fischer, Conrad. Master The Boards. Print.
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Uptodate.com,. 'Infantile Hypertrophic Pyloric Stenosis'. N.p., 2015. Web. 15 Nov. 2015.
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al-Salem AH, et al. 'Infantile Hypertrophic Pyloric Stenosis And Congenital Diaphragmatic Hernia. - Pubmed - NCBI'. Ncbi.nlm.nih.gov. N.p., 2015. Web. 15 Nov. 2015.
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Kliegman, Robert. Nelson Textbook Of Pediatrics. Print.
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Med.cmu.ac.th,. 'Infants With Vomitting'. N.p., 2015. Web. 15 Nov. 2015. (Figure 1).
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Tdo.sagepub.com,. 'Sign In'. N.p., 2015. Web. 15 Nov. 2015. (Figure 2).
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Med-ed.virginia.edu,. 'Pediatric Radiology'. N.p., 2015. Web. 15 Nov. 2015. (Figure 3).
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Learningradiology.com,. 'Learningradiology-Hypertrophic, Pyloric Stenosis'. N.p., 2015. Web. 15 Nov. 2015. (Figure 4).
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Shah, Samir S, Jeanine C Ronan, and Brian Alverson. Step-Up To Pediatrics. Print.
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Kaplan Step 1 video, Pathology, 2015.
Written by: Roaa Amer
Reviewed by: Adel Yasky
Lama Al Luhidan
Web publisher: Adel Yasky
Bayan Alzomaili
Audio recording:
Read by: Bayan Alzomaili
Directed by: Rana Alzahrani
Audio production: Bayan Alzomaili