Dr Mutuna Chiwele, general surgeon specialist from Livingstone Central Hospital, Zambia gives a lecture to Cavendish University medical students on hypertrophic pyloric stenosis. The following are discussed: 1. Aetiological factors 2. Pathological features 3. Clinical manifestation Investigations & Diagnosis 4. Management 5. Surgical Intervention 6. Postoperative Care

1. Hypertrophic Pyloric Stenosis
Dr Mutuna Chiwele
General Surgeon Specialist
Livingstone Central Hospital

2. Aetiological Factors
• Family history
• Male to female ratio is 5:1.
• Incidence – 3/1000

3. Pathological Features
• Condition characterized by hypertrophy of
smooth muscles of the stomach.
• Usually becomes apparent after 3-4 weeks of
birth.

4. Clinical Manifestation
• Usually starts 3-4 weeks after birth
• Persistent projectile vomiting may be
associated with gastro-oesophageal reflux.
• At the beginning of disease baby appears well
but the weight gain is poor.
• Small green quantities of stool are
infrequently passed.

5. • Gradually baby starts to develop dehydration
with hypochloraemic alkalosis with pallor.
• Left to right gastric peristaltic waves often
appear.
• A small pyloric tumour may be felt- olive sized,
firm & mobile in right hypochondrium
(contracted pyloric muscles).

6. Investigations & Diagnosis
• Blood gas analysis- hypochloraemic alkalosis
with hyponatraemia, hypokalaemia &
decreased chloride.
• Ultrasound may show a thickened elongated
pyloric muscle with increased muscle to
lumen ratio & decreased fluid movement.
• Diluted gastrograffin meal shows enlarged
stomach & elongated narrow pyloric canal.

7. Management
• Intravenous rehydration according to fluid
regime adopted.
• Hypovolaemia if present is corrected using
0.9% saline.
• Electrolytes & alkalosis should be corrected
over 48hrs using 0.45% sodium chloride & 5%
dextrose with potassium 1-2mmol/kg at a rate
of 100-120ml/kg/day.

8. • Nasogastric tube should be inserted to
prevent aspiration of vomited secretion thus
eliminating aspiration complications.

9. Surgical Intervention
• Through a right upper quadrant incision
pylorus is exposed & hypertrophic muscle
fibers are divided cautiously taking care not to
open the mucosa (using 15 blade knife & fine
mosquito forceps for dissection).
• When muscles are divided mucosa bulges
through divided muscles.
• Avoid injury of pre-pyloric vein or Mayo vein

10. Postoperative Care
• Start feeding 4 hours postoperatively &
increase amount gradually over next 24-36
hours.