â– LECTURE OVERVIEW: Infantile Hypertrophic Pyloric Stenosis is a metabolic and mechanical obstruction disorder of the gastric outlet.
â– STENOSIS MECHANISMS:
1. Pyloric Hypertrophy: Hypertrophy and hyperplasia of the circular smooth muscle fibers of the pyloric sphincter.
2. Channel Compression: The pyloric canal is physically elongated and narrowed, completely obstructing gastric emptying.
3. Vomiting Phase: Swallowed milk accumulates in the stomach, leading to non-bilious projectile vomiting.
4. Hydrogen/Chloride Wasting: Agonizing gastric vomiting wastes hydrochloric acid (HCl) and sodium.
5. Compensatory Alkalosis: Loss of acid drives the kidneys to retain bicarbonate, resulting in hypokalemic hypochloremic metabolic alkalosis.
â– RADIOGRAPHIC DIAGNOSTIC CRITERIA:
Imaging modalities (such as high-resolution CT, contrast-enhanced MRI, and point-of-care ultrasound) show characteristic density shifts, enhancement patterns, or structural deviations.
â– SURGICAL COMPASS & ANATOMICAL CORRELATION:
Dissection lines must respect established fascial boundaries to prevent neurovascular traction injuries and secure excellent diagnostic margins.
[HY-BOARD-1197]
🌟 Dynamic Clinical Key:
Presents in first-born male infants between 2 and 6 weeks of age with non-bilious projectile vomiting after feeding. Examination reveals a palpable, firm 'olive-shaped' mass in the epigastrium. Surgical repair with a pyloromyotomy is curative. Always correlate imaging signs with clinical presentation to avoid unnecessary surgical explorations of benign incidentalomas. Verify landmarks dynamically with gentle palpation and specialized intraoperative markers.