Details of the pyloromyotomy – open technique are discussed below:
Congenital hypertrophic pyloric stenosis – this condition occurs in infants and is marked by a thickening of the pylorus which is the muscular band of tissue in the stomach that controls the exit of food and gastric juices from the stomach.
Projectile vomiting – this vomiting occurs after feeds and is first seen in infants several weeks after birth. To experienced clinicians this alone is highly suggestive of this condition
Presence of an “olive” on palpation – often the hypertrophic (overgrown) pylorus muscle can be palpated (felt) on exam by an experienced surgeon. It literally feels like an olive in the right upper quadrant beneath the right costal margin (right rib cage) when direct, firm pressure is placed.
Pre-operative Workup and Preparation
Correction of electrolyte imbalance – infants with pyloric stenosis and vomiting typically have derangements of serum electolytes such as low potassium and magnesium.
Correction of fluid balance – this is done through an intravenous line inserted peripherally and an infusion of 5% dextrose in normal saline usually at the rate of 10ml/Kg. This is considered maintenance fluid. Any preceding fluid deficit is then made up by using 5% dextrose in alternating solutions of normal saline and water for 12-24 hours or until adequate urine output has been established.
Correction of acid/base balance – this usually occur with correction of the fluid deficit and potassium loss.
Placement of nasogastric tube – after the diagnosis the infant oral feeds for the infant are suspended. Although prolonged placement of a nasogastric tube is to be avoided, sometimes 6-12 hours is needed to prevent further vomiting.
Surgical Details of Pyloromyotomy
1. A small 3 cm incision is made in the skin with a No. 15 blade just below the right costal margin (the right rib cage) on the anterior abdominal wall, but above the inferior edge of the liver.
2. Care must be taken to place the Â pyloromyotomy incision so that it extends laterally from the outer edge of the rectus muscle.
3. Dissection is done through the subcutaneous tissues with Bovie cautery.
4. The muscle layer is carefully divided using Bovie cautery with the omentum or transverse colon presenting into the wound.
5. Using very gentle traction on the omentum the transverse colon if not already visualized through the wound can be presented up into the wound.
6. Gentle traction on the transverse colon will then deliver the greater curvature of the stomach up into the wound.
7. The anterior wall of the stomach is grasped with a moist sponge and gentle traction on the stomach antrum is applied – this will deliver the pylorus into the wound.
8. The avascular (without blood supply) portion of the anterior wall of the pylorus is identified.
9. The pylorus is held between the surgeons thumb and forefinger and a 1-2 cm longitudinal incision (along the plane of the pylorus) is made.
10. The incision is taken down through the serosal and muscle layers until the mucosa is exposed.
11. Great care must be taken not to incise the mucosa. Extra attention must be given to the duodenal end of the incision as the muscle layer ends abruptly.
12. The incised (cut) muscle is gently spread apart with a hemostat until the mucosa “puffs up” to the level of the cut serosa.
13. The peritoneum and fascia of the transversalis muscle is closed with a running absorbable suture.
14. The remaining fascial layers are closed with either running or interrupted slowly absorbable sutures.
15. The skin is closed with a subcuticular absorbable suture such as Monocryl.
16. Collodian or adhesive Steri-strips are placed on the wound to complete the pyloromyotomy.