Pylorus | Find Me A Cure

Alternative Name : Infantile hypertrophic pyloric stenosis

Definition:
Pyloric stenosis is a condition that causes severe vomiting in the first few months of life. There is narrowing (stenosis) of the opening from the stomach to the intestines, due to enlargement (hypertrophy) of the muscle surrounding this opening (the pylorus, meaning “gate”), which spasms when the stomach empties. It is uncertain whether there is a real congenital narrowing or whether there is a functional hypertrophy of the muscle which develops in the first few weeks of life. Babies with this condition may seem to always be hungry
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Pyloric stenosis also occurs in adults where the cause is usually a narrowed pylorus due to scarring from chronic peptic ulceration. This is a different condition from the infantile form.

Prompt treatment of pyloric stenosis is important for preventing complications. Pyloric stenosis can be corrected with surgery.

Males are more commonly affected than females, with firstborn males affected about four times as often, and there is a genetic predisposition for the disease. It is commonly associated with people of Jewish ancestry, and has multifactorial inheritance patterns. Pyloric stenosis is more common in Caucasians than Hispanics, Blacks, or Asians. The incidence is 2.4 per 1000 live births in Caucasians , 1.8 in Hispanics, 0.7 in Blacks, and 0.6 in Asians. It is also less common amongst children of mixed race parents. Caucasian babies with blood type B or O are more likely than other types to be affected

Symptoms:
Signs of pyloric stenosis usually appear within three to five weeks after birth. Pyloric stenosis is rare in babies older than age 3 months.

Signs and symptoms are:
*Frequent projectile vomiting. Pyloric stenosis often causes projectile vomiting — the forceful ejection of milk or formula up to several feet away — within 30 minutes after your baby eats. Vomiting may be mild at first and gradually become more severe. The vomit may sometimes contain blood.

*Persistent hunger. Babies who have pyloric stenosis often want to eat soon after vomiting.

*Stomach contractions. You may notice wave-like contractions that move across your baby’s upper abdomen (peristalsis) soon after feeding but before vomiting. This is caused by stomach muscles trying to force food past the outlet of the pylorus.

*Dehydration. Your baby may cry without tears or become lethargic. You may find yourself changing fewer wet diapers or diapers that aren’t as wet as you expect.

*Changes in bowel movements. Since pyloric stenosis prevents food from reaching the intestines, babies with this condition may be constipated.

*Weight problems. Pyloric stenosis can prevent a baby from gaining weight, and can sometimes even cause weight loss.

*Less active or seems unusually irritable

*Urinating much less frequently or is having noticeably fewer bowel movements

Causes:
The cause of the thickening is unknown, although genetic factors may play a role. Children of parents who had pyloric stenosis are more likely to have this problem.

Normally, food passes easily from the stomach into the duodenum (the first part of the small intestine) through a valve called the pylorus. In pyloric stenosis, the muscles of the pylorus are thickened. This thickening prevents the stomach from emptying into the small intestine.

Risk Factors:
Risk factors for pyloric stenosis include:

*Sex. Pyloric stenosis occurs more often in males than in females.

*Birth order. About one-third of babies affected by pyloric stenosis are firstborns.

*Family history. More than 1 in 10 babies with pyloric stenosis has a family member who had the disorder.

*Early antibiotic use. Babies given certain antibiotics, such as erythromycin, in the first weeks of life for whooping cough (pertussis) have an increased risk of pyloric stenosis. In addition, babies born to mothers who were given certain antibiotics in late pregnancy also may have an increased risk of pyloric stenosis.

Complications:
Pyloric stenosis can lead to:

*An electrolyte imbalance. Electrolytes are minerals, such as chloride and potassium, that circulate in the body’s fluids to help regulate many vital functions, such as heartbeat. When a baby vomits every time he or she eats, dehydration and an imbalance of electrolytes eventually occurs

*Stomach irritation. Repeated vomiting can irritate your baby’s stomach. This irritation may even cause mild bleeding.

*Jaundice. Rarely, infants who have pyloric stenosis develop jaundice — a yellowish discoloration of the skin and eyes caused by a buildup of a substance secreted by the liver called bilirubin.

Diagnosis:
Diagnosis is via a careful history and physical examination, often supplemented by radiographic studies. There should be suspicion for pyloric stenosis in any young infant with severe vomiting. On exam, palpation of the abdomen may reveal a mass in the epigastrium. This mass, which consists of the enlarged pylorus, is referred to as the ‘olive,’ and is sometimes evident after the infant is given formula to drink. It is an elusive diagnostic skill requiring much patience and experience. There are often palpable (or even visible) peristaltic waves due to the stomach trying to force its contents past the narrowed pyloric outlet.

At this point, most cases of pyloric stenosis are diagnosed/confirmed with ultrasound, if available, showing the thickened pylorus. Although somewhat less useful, an upper GI series (x-rays taken after the baby drinks a special contrast agent) can be diagnostic by showing the narrowed pyloric outlet filled with a thin stream of contrast material; a “string sign” or the “railroad track sign”. For either type of study, there are specific measurement criteria used to identify the abnormal results. Plain x-rays of the abdomen are not useful, except when needed to rule out other problems.

Blood tests will reveal hypokalemic, hypochloremic metabolic alkalosis due to loss of gastric acid (which contain hydrochloric acid and potassium) via persistent vomiting; these findings can be seen with severe vomiting from any cause. The potassium is decreased further by the body’s release of aldosterone, in an attempt to compensate for the hypovolaemia due to the severe vomiting.

Pathophysiology
The gastric outlet obstruction due to the hypertrophic pylorus impairs emptying of gastric contents into the duodenum. As a consequence, all ingested food and gastric secretions can only exit via vomiting, which can be of a projectile nature. The vomited material does not contain bile because the pyloric obstruction prevents entry of duodenal contents (containing bile) into the stomach.

This results in loss of gastric acid (hydrochloric acid). The chloride loss results in hypochloremia which impairs the kidney’s ability to excrete bicarbonate. This is the significant factor that prevents correction of the alkalosis.

A secondary hyperaldosteronism develops due to the hypovolemia. The high aldosterone levels causes the kidneys to:

*avidly retain Na+ (to correct the intravascular volume depletion)

*excrete increased amounts of K+ into the urine (resulting in hypokalaemia).

The body’s compensatory response to the metabolic alkalosis is hypoventilation resulting in an elevated arterial pCO2.=[pp\][[\=0808i[po9il;

Treatment:
Infantile pyloric stenosis is typically managed with surgery; very few cases are mild enough to be treated medically.

Prior to surgery and surgery alternatives:
The danger of pyloric stenosis comes from the dehydration and electrolyte disturbance rather than the underlying problem itself. Therefore, the baby must be initially stabilized by correcting the dehydration and hypochloremic alkalosis with IV fluids. This can usually be accomplished in about 24–48 hours.

Intravenous and oral atropine may be used to treat pyloric stenosis. It has a success rate of 85-89% compared to nearly 100% for pyloromyotomy, however it requires prolonged hospitalization, skilled nursing and careful follow up during treatment. It might be an alternative to surgery in children who have contraindications for anesthesia or surgery.

Surgery
The definitive treatment of pyloric stenosis is with surgical pyloromyotomy known as Ramstedt’s procedure (dividing the muscle of the pylorus to open up the gastric outlet). This is a relatively straightforward surgery that can possibly be done through a single incision (usually 3–4 cm long) or laparoscopically (through several tiny incisions), depending on the surgeon’s experience and preference.
CLICK & SEE THE PICTURES
Today, the laparoscopic technique has largely supplanted the traditional open repairs which involved either a tiny circular incision around the navel or the Ramstedt procedure. Compared to the older open techniques, the complication rate is equivalent, except for a markedly lower risk of wound infection.[9] This is now considered the standard of care at the majority of Children Hospitals across the US, although some surgeons still perform the open technique. Following repair, the small 3mm incisions are hard to see.

The vertical incision, pictured and listed above, is no longer usually required. Though many incisions have been horizontal in the past years.

Once the stomach can empty into the duodenum, feeding can commence. Some vomiting may be expected during the first days after surgery as the gastro-intestinal tract settles. Very occasionally the myotomy was incomplete and projectile vomiting continues, requiring repeat surgery. But the condition generally has no long term side-effects or impact on the child’s future.

Prognosis:
Surgery usually provides complete relief of symptoms. The infant can usually tolerate small, frequent feedings several hours after surgery.

Prevention
There are no known ways of preventing pyloric stenosis, although it is possible that breastfeeding might reduce the risk.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://en.wikipedia.org/wiki/Pyloric_stenosis
http://www.mayoclinic.com/health/pyloric-stenosis/DS00815
http://www.nlm.nih.gov/medlineplus/ency/article/000970.htm
http://www.bbc.co.uk/health/physical_health/conditions/pyloricstenosis.shtml
http://www.empowher.com/media/reference/pyloric-stenosis