II. Epidemiology
- Ages 3-6 weeks old (mean 3 weeks, up to 12 weeks of age)
III. Pathophysiology
- Hypertrophy of pylorus of the Stomach causing a gastric outlet obstruction
IV. Risk factors
- Family History of Pyloric Stenosis (especially northern european)
- Male gender (4 times more common than in girls)
- Other possible risk factors
- Bottle Feeding (Formula Feeding)
- Prematurity
- Maternal Tobacco Abuse
- Maternal Hyperthyroidism
- Macrolide Antibiotic use in the first 2 weeks of life
V. Symptoms: Vomiting
- Non-Bilious Vomiting that is more forceful than Spitting Up
- Starts intermittently
- Progressively increases in frequency and severity
- Infant remains hungry despite Vomiting
- Projectile Vomiting in up to 70% of cases
VI. Signs
- Typically, otherwise well appearing infant with benign Abdomen
- Palpable swelling ("olive") present in >60% of cases in past when delayed presentation was common
- In 2016 olive is rare due to early presentations
- Inferior to xiphoid process and inferior or deep to left liver edge
VII. Labs
- Basic metabolic panel
- Hypochloremic hypokalemic Metabolic Alkalosis
- Rarely seen due to early presentations in U.S.
- Other findings
- Hyponatremia
- Hypoglycemia
- Increased Renal Function tests (Serum Creatinine, Blood Urea Nitrogen)
- Hypochloremic hypokalemic Metabolic Alkalosis
VIII. Imaging: Pyloric Ultrasound
- Technique
- Linear probe in subxiphoid location, horizontal probe
- Look for gastric rugae, smooth outer serosal surface, slightly thicker wall
- Trace the outer surface of the Stomach down to the pylorus and duodenum
- Duodenal wall is much thinner than pylorus
- Diagnosis
- Thickened and elongated pylorus
- Pylorus wall thickness >3 mm
- Pylorus diameter >13 mm
- Pylorus length >15 mm (variable)
- No relaxation
- No fluid passage within channel
- May see very minimal flow (string sign)
- Thickened and elongated pylorus
- Efficacy
- Test Sensitivity and Test Specificity approach 100%
IX. Differential Diagnosis
X. Complications
- Pediatric Dehydration
- Hypochloremic hypokalemic Metabolic Alkalosis
- Rarely seen due to early presentations in U.S.
XI. Management
- Correct fluid and Electrolyte abnormalities
- Risk of postoperative apnea if not corrected
- Surgery (pyloromyotomy)
- Loosens pyloric Muscle
XII. Resources
- Pyloric Stenosis Ultrasound
XIII. References
- Bukata (2013) Pediatric Emergencies, EM Bootcamp, CEME
- Nazer (2013) Pediatric Hypertrophic Pyloric Stenosis, EMedicine
- Nirappil (2021) Crit Dec Emerg Med 35(8):12-3
Images: Related links to external sites (from Bing)
Related Studies
| Definition (NCI) | Narrowing of the pyloric lumen caused either by hypertrophy of the surrounding muscles or tissue scarring due to a chronic peptic ulcer. |
| Definition (MSH) | Narrowing of the pyloric canal with varied etiology. A common form is due to muscle hypertrophy (PYLORIC STENOSIS, HYPERTROPHIC) seen in infants. |
| Concepts | Finding (T033) |
| MSH | D011707 |
| ICD10 | K31.1 |
| SnomedCT | 367403001 |
| English | Pyloric Stenosis, PYLORIC STENOSIS, pyloric stenosis (diagnosis), pyloric stenosis, Pyloric Stenosis [Disease/Finding], gastric outflow obstruction, pyloric stenoses, pyloric stenosi, gastric outlet obstruction, pyloric obstruction, Gastric Outlet Obstruction, Pylorus--Stenosis, Pyloric stenosis, PS - Pyloric stenosis, Pyloric stenosis (disorder), pylorus; stenosis, pylorus; stricture, stenosis; pylorus, stricture; pylorus, Stenosis, Pyloric, Pyloric stenosis NOS, Stenosis pyloric |
| Portuguese | ESTENOSE PILORICA, Estenose pilórica, Estenose pilórica NE, Estenose Pilórica |
| Spanish | ESTENOSIS PILORICA, Estenosis pilórica, Estenosis pilórica NEOM, estenosis pilórica (trastorno), estenosis pilórica, Estenosis Pilórica |
| German | PYLORUSSTENOSE, Pylorusstenose NNB, Pylorusstenose |
| Dutch | pylorusstenose, stenose pylorus, pylorusstenose NAO, pylorus; stenose, pylorus; strictuur, stenose; pylorus, strictuur; pylorus, Pylorusstenose, Stenose, pylorus- |
| Italian | Stenosi del piloro, Stenosi del piloro NAS, Stenosi pilorica |
| French | Sténose du pylore SAI, STENOSE DU PYLORE, Sténose pylorique, Sténose du pylore |
| Japanese | 幽門狭窄ＮＯＳ, ﾕｳﾓﾝｷｮｳｻｸNOS, ﾕｳﾓﾝｷｮｳｻｸ, 幽門狭窄, 幽門狭窄症 |
| Swedish | Pylorusförträngning |
| Czech | pylorus - stenóza, Pylorostenóza, Pylorostenóza NOS |
| Finnish | Mahanportin ahtauma |
| Russian | PILOROSTENOZ, ПИЛОРОСТЕНОЗ |
| Polish | Zwężenie odźwiernika |
| Hungarian | Pylorus stenosis k.m.n., Stenosis pylorikus, Pylorus stenosis |
| Norwegian | Pylorusstenose, Magemunnsforsnevring |
Ontology: Pyloric Stenosis, Hypertrophic (C0700639)
| Definition (NCI) | An abnormality characterized by thickening of the muscle in the wall of the pylorus. It results in the narrowing of the pyloric channel. The overlying mucosa may appear hypertrophic as well. Clinical signs and symptoms appear early in life and include projectile vomiting and dehydration. |
| Definition (MSH) | Narrowing of the pyloric canal due to HYPERTROPHY of the surrounding circular muscle. It is usually seen in infants or young children. |
| Concepts | Congenital Abnormality (T019) , Disease or Syndrome (T047) |
| MSH | D046248 |
| ICD9 | 750.5 |
| ICD10 | Q40.0 |
| SnomedCT | 48644003 |
| English | Cong hypertroph pylor stenosis, Pyloric stenosis, hypertrophic, Cong pyloric stenosis, Pyloric Stenosis, Hypertrophic [Disease/Finding], hypertrophic pyloric stenosis, pyloric hypertrophic stenosis, Hypertrophic pyloric stenosis, Congenital hypertrophic pyloric stenosis, Congenital hypertrophic pyloric stenosis (disorder), hypertrophy; pylorus, infantile, infantile; pyloric obstruction, pylorus; hypertrophy, infantile, Hypertrophic Pyloric Stenosis, Pyloric Stenosis, Hypertrophic, Stenosis, Hypertrophic Pyloric, Stenosis pyloric hypertrophic congenital, Congenital or infantile constriction of pylorus, Congenital or infantile hypertrophy of pylorus, Congenital or infantile stenosis of pylorus, Congenital or infantile stricture of pylorus |
| Dutch | congenitale hypertrofe pylorusstenose, hypertrofie; pylorus, infantiel, infantiel; pylorusobstructie, pylorus; hypertrofie, infantiel, Congenitale hypertrofische pylorusstenose, Hypertrofische pylorusstenose, Pylorusstenose, hypertrofische, Stenose, hypertrofische pylorus- |
| French | Sténose hypertrophique congénitale du pylore, Sténose pylorique hypertrophique congénitale, Sténose hypertrophique du pylore, Sténose pylorique hypertrophique |
| German | Pylorusstenose hypertrophisch kongenital, kongenitale hypertrophische Pylorusstenose, Angeborene hypertrophische Pylorusstenose, Hypertrophische Pylorusstenose, Pylorusstenose, hypertrophische, Stenose des Pylorus, hypertrophische |
| Italian | Stenosi ipertrofica congenita del piloro, Stenosi pilorica ipertrofica congenita, Stenosi pilorica ipertrofica |
| Portuguese | Estenose congénita hipertrófica do piloro, Estenose hipertrófica congénita do piloro, Estenose Pilórica Hipertrófica |
| Spanish | Estenosis hipertrófica del píloro congénita, Estenosis pilórica hipertrófica congénita, estenosis hipertrófica del píloro congénita (trastorno), estenosis hipertrófica del píloro congénita, estenosis pilórica hipertrófica congénita, Estenosis Hipertrofica de Piloro |
| Japanese | 先天性肥厚性幽門狭窄症, ｾﾝﾃﾝｾｲﾋｺｳｾｲﾕｳﾓﾝｷｮｳｻｸｼｮｳ, 肥厚性幽門狭窄症, 幽門狭窄症-肥厚性 |
| Swedish | Pylorusstenos, hypertrofisk |
| Czech | pylorus - stenóza hypertrofická, Kongenitální hypertrofická pylorostenóza, Vrozená hypertrofická stenóza pyloru |
| Finnish | Hypertrofinen mahanportin ahtauma |
| Russian | PRIVRATNIKA STENOZ GIPERTROFICHESKII, PILOROSTENOZ GIPERTROFICHESKII, ПИЛОРОСТЕНОЗ ГИПЕРТРОФИЧЕСКИЙ, ПРИВРАТНИКА СТЕНОЗ ГИПЕРТРОФИЧЕСКИЙ |
| Korean | 선천 비대성 날문협착(유문협착) |
| Polish | Zwężenie odźwiernika przerostowe |
| Hungarian | Veleszületett stenosis pylorikus hypertrophiás, Veleszületett hypertrophiás pylorikus szűkület |
| Norwegian | Hypertrofisk pylorusstenose |
