👁️ Classic Clinical Signs of CHPS — Examiner's Favourites
Visible Gastric Peristalsis
Left-to-right peristaltic wave seen through abdominal wall after a feed — pathognomonic when present
Olive-Shaped Tumour
Palpable pyloric mass in the right hypochondrium / epigastrium — firm, mobile, felt best after vomiting. Present in ~60–80% of cases
Projectile Vomiting
Non-bilious (above ampulla of Vater), forceful, may hit across the room. Immediately hungry after vomiting — 'hungry vomiter'
Test Feed
Examination after a feed — best time to demonstrate all three signs: visible peristalsis, palpable olive, and the vomiting episode itself
⚗️ The Classic Metabolic Derangement in CHPS
Hypochloraemic Metabolic Alkalosis
Loss of HCl in vomit → ↓Cl⁻, ↑HCO₃⁻, ↑pH — the hallmark biochemical finding
Hypokalaemia
K⁺ shifts intracellularly in alkalosis; renal K⁺ wasting (aldosterone-driven); direct loss in gastric juice
Paradoxical Aciduria
Despite systemic alkalosis, urine becomes acidic — kidneys preferentially conserve Na⁺ at expense of H⁺ excretion (volume depletion overrides alkalosis correction)
Hyponatraemia (late)
Occurs in severe/prolonged cases — dilutional or due to ADH release from hypovolaemia
🔪 Ramstedt's Pyloromyotomy — Surgical Pearls
Procedure (Ramstedt, 1912)
Longitudinal incision through serosa and circular muscle of pylorus — WITHOUT cutting the mucosa. Muscle splits apart, mucosa bulges up, relieving obstruction
Approaches
Open (right upper quadrant / periumbilical / transverse) or Laparoscopic (3-port). Laparoscopic is now preferred — faster recovery, better cosmesis, equivalent outcomes
Feared Intraoperative Complication
Mucosal perforation — especially at duodenal end where mucosa is thinnest. If suspected, repair + return to theatre; test with methylene blue or air insufflation
Post-op Feeding Protocol
Early feeding (4–6 hours post-op): clear fluids → breast/formula milk. Mild post-op vomiting is expected for 24–48 hours due to oedema; not a sign of failed myotomy
📚 Historical Note & Eponym: Congenital Hypertrophic Pyloric Stenosis was first described anatomically by Beardsley in 1788. The first successful surgical treatment — pyloromyotomy — was performed by Conrad Ramstedt in 1912 in Münster, Germany. Before Ramstedt's operation, mortality was near 100%. The operation remains essentially unchanged over a century later, a testament to its elegance. Earlier surgical attempts (e.g., gastrojejunostomy by Loreta and others) were largely unsuccessful. Hirschsprung incorrectly attributed the vomiting to spasm rather than mechanical obstruction in some early descriptions.