Pyloric stenosis is a condition affecting the muscular valve between the stomach and the small intestine in infants. This muscle, called the pylorus, becomes thickened and enlarged, creating a narrowing that prevents food from passing into the intestine. The blockage creates a gastric outlet obstruction, making it impossible for the baby to retain nourishment.
This condition manifests when an infant is between two and eight weeks old, although it can appear anytime up to six months of age. Surgery is the definitive treatment for this obstruction. The modern approach is the laparoscopic pyloromyotomy, a minimally invasive procedure that has become the standard of care.
Recognizing Pyloric Stenosis
Pyloric stenosis presents with progressively worsening episodes of vomiting. This vomiting is non-bilious (lacking bile) and notably projectile, often propelling milk or formula several feet away, distinguishing it from typical infant spit-up.
Since food cannot enter the small intestine, the infant remains hungry and often eagerly feeds again immediately after vomiting. The frequent loss of stomach contents, including acid and electrolytes, leads to dehydration and chemical imbalances. Visible wavelike contractions across the abdomen, known as peristaltic waves, may be observed as the stomach attempts to force food past the obstruction.
Diagnosis often begins with a physical examination, where a clinician may feel the thickened pylorus as a firm, olive-shaped mass in the right upper abdomen. The standard diagnostic tool is an abdominal ultrasound, which allows for precise measurement of the pyloric muscle.
Pyloric stenosis is confirmed when the ultrasound shows a thickened pyloric muscle, typically exceeding three or four millimeters. Before surgery, the infant’s fluid and electrolyte status must be stabilized. Severe vomiting causes a loss of chloride and hydrogen ions, resulting in a metabolic alkalosis that requires intravenous correction.
Fluid resuscitation is necessary to correct dehydration and normalize electrolyte imbalances, which may take up to 24 hours or longer in severe cases. The surgery is carefully planned, executed only after the baby is medically stable to ensure safe general anesthesia.
The Laparoscopic Pyloromyotomy Procedure
The surgical treatment is the pyloromyotomy, a technique originally described by Conrad Ramstedt. This procedure involves longitudinally splitting the outer muscle layer of the pylorus while leaving the inner mucosal lining intact. This action relieves the obstruction by allowing the muscle fibers to spread apart, creating a wider channel for food passage.
The laparoscopic approach uses minimally invasive techniques. Instead of a single, larger incision, the surgeon makes two or three tiny incisions, typically three to five millimeters long. A laparoscope (thin camera) is inserted through one incision, often near the belly button, projecting a magnified view of the internal structures onto a monitor.
Specialized instruments are introduced through the other small incisions. The abdomen is gently inflated with carbon dioxide gas to create a working space, a technique known as pneumoperitoneum. The surgeon uses these instruments to grasp the pylorus and make a precise longitudinal incision through the hypertrophied muscle.
The pyloric muscle is cut from the antrum of the stomach down to the prepyloric vein of Mayo. A blunt instrument, such as a pyloric spreader, is then used to carefully separate the muscle fibers. The muscle is spread until the inner lining (mucosa) bulges slightly through the opening, confirming that the obstruction is relieved.
The laparoscopic method offers reduced trauma compared to traditional open surgery. Smaller incisions result in less post-operative pain and superior cosmetic outcomes, often leaving barely noticeable scars. This minimally invasive technique is associated with a shorter hospital stay and a faster return to oral feeding.
Performing the pyloromyotomy laparoscopically maintains the same effectiveness as the traditional open technique while being less invasive. Specialized equipment and the magnified view assist the surgeon in performing the delicate muscle split, helping to avoid perforation of the mucosa. The entire process often takes less than an hour to complete.
Immediate Post-Surgical Care and Long-Term Outlook
Following the pyloromyotomy, the infant is closely monitored in recovery. Pain management is straightforward, often involving non-opioid medications like acetaminophen. Intravenous fluids continue until the baby can tolerate adequate oral intake.
Feeding is reintroduced gradually through a systematic protocol, sometimes called a “feed ladder.” Oral intake begins a few hours after surgery, starting with small volumes of clear liquids. If tolerated, the volume is slowly increased, progressing to full-strength formula or breast milk over the next 24 to 48 hours.
Some vomiting commonly persists immediately after the operation. This temporary emesis is usually attributed to swelling at the surgical site or the stomach adjusting to normal function. Parents are informed that this post-operative vomiting should decrease in frequency and volume over the first one to three days.
The hospital stay after successful feeding advancement is short, often allowing discharge within 24 to 48 hours once the infant tolerates full feeds. Once discharged, the baby can resume normal activities and feeding without restriction. Follow-up with the surgeon is scheduled within one or two weeks to check incision sites and ensure proper weight gain.
The long-term outlook for infants who undergo a pyloromyotomy is excellent, as the procedure is curative. Once the thickened muscle is split, the blockage is permanently resolved, and normal gastric emptying is restored. Long-term gastrointestinal problems are rare. Although subtle differences in pyloric muscle motility may be detectable years later, the overall rate of gastric emptying remains normal.