pyloric stenosis (redirected from Congenital Hypertropic Pyloric Stenosis)

Pyloric Stenosis 

Definition

Pyloric stenosis refers to a narrowing of the passage between the stomach and the small intestine. The condition, which affects infants during the first several weeks of life, can be corrected effectively with surgery.

Description

Frequent vomiting may be an indication of pyloric stenosis. The pylorus is the passage between the stomach and the small intestine. During the digestive process food passes through the pylorus, which is located near the bottom of the stomach, on its way to the intestines. In pyloric stenosis, the muscular wall of the passage becomes abnormally thickened. This causes the pylorus to become too narrow, which prevents food from emptying out of the stomach in a normal fashion. The partially digested contents of the stomach are forced upwards into the mouth. As a result, a baby with pyloric stenosis often vomits after feedings.

The condition affects one in 4,000 infants. Most are diagnosed between three and five weeks old, though some babies may show symptoms during the first or second week of life. Infants with a family history of pyloric stenosis are more at risk for the condition, which tends to occur less often in females, blacks, and Asians. Pyloric stenosis is also referred to as hypertrophic pyloric stenosis.

Causes and symptoms

The cause of pyloric stenosis is not known. The main symptom is vomiting after feedings. These episodes of vomiting usually get worse over time, happening more often and becoming more forceful (forceful vomiting is often called "projectile" vomiting). Other symptoms include increased appetite, weight loss, infrequent bowel movements, belching, and diarrhea. Due to dehydration, the infant may also have fewer wet diapers.

Diagnosis

The clinician will examine the baby and talk with the parents about their infant's symptoms. If a child has the condition, the doctor should be able to feel a hard mass (about 2 cm wide and olive shaped) in the area above the bellybutton. If the doctor cannot detect the mass, ultrasonography will be done to confirm the diagnosis. A blood test may also be performed to see if the infant is dehydrated, in which case intravenous fluids can be used to correct the problem.

Treatment

Pyloric stenosis can be cured with a surgical procedure called a pyloromyotomy. In this operation, the surgeon makes an incision in the baby's abdomen. Then a small cut is made in the thickened muscle of the pylorus and it is spread apart. In this manner, the passage can be widened without removing any tissue. (The procedure may be performed with the aid of a laparoscope.) After surgery, the pylorus will heal itself. The thickening gradually goes away and the passage resumes a normal shape. The whole procedure (including anesthesia) takes about an hour.

Most babies go home one or two days after surgery. Any mild discomfort can be controlled with Tylenol. The infant may still vomit occasionally after surgery, but this is not usually a cause for alarm. However, if vomiting occurs three or more times a day, or for several consecutive days, the baby's pediatrician should be notified.

Alternative treatment

None known.

Prognosis

Surgery is often a complete cure. Most infants do not experience complications or long-term effects.

Prevention

It is not known how to prevent pyloric stenosis.

Resources

Books

Behrman, Richard E., et al., Nelson Textbook of Pediatrics. Philadelphia: WB Saunders, 2000.

Periodicals

Yoshizawa J, et al. Ultrasonographic Features of Normalizationof the Pylorus after Pyloromyotomy for Hypertrophic Pyloric Stenosis. "Journal of PediatricSurgery" 36 (April 2001): 582-6.

Organizations

American Academy of Family Physicians. 11400 Tomahawk Creek Parkway, Leawood, KS 66211-2672. (913) 906-6000. http://www.aafp.org/. fp@aafp.org.

American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007-1098. (847) 434-4000. http://www.aap.org.

Key terms

Laparoscope — A thin, camera-fitted tube that can be inserted into the abdomen in order to view internal organs.

Stenosis — The narrowing of a passage (such as the pylorus).

Ultrasonography — A non-invasive imaging procedure that uses high-frequency sound waves.

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stenosis /ste·no·sis/ (stĕ-no´sis) pl. steno´ses   [Gr.] stricture; an abnormal narrowing or contraction of a duct or canal.

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aortic stenosis  (AS) a narrowing of the aortic orifice of the heart or of the aorta near the valve.

hypertrophic pyloric stenosis  narrowing of the pyloric canal due to muscular hypertrophy and mucosal edema, usually in infants.

hypertrophic subaortic stenosis , idiopathic hypertrophic subaortic stenosis (IHSS) a form of hypertrophic cardiomyopathy in which the left ventricle is hypertrophied and the cavity is small; it is marked by obstruction to left ventricular outflow.

infantile hypertrophic gastric stenosis  congenital hypertrophy and hyperplasia of the musculature of the pyloric sphincter, leading to partial obstruction of the gastric outlet.

mitral stenosis  a narrowing of the left atrioventricular orifice.

pulmonary stenosis  (PS) narrowing of the opening between the pulmonary artery and the right ventricle, usually at the level of the valve leaflets.

pyloric stenosis  obstruction of the pyloric orifice of the stomach; it may be congenital or acquired.

renal artery stenosis  narrowing of one or both renal arteries, so that renal function is impaired, resulting in renal hypertension and, if stenosis is bilateral, chronic renal failure.

subaortic stenosis  aortic stenosis due to an obstructive lesion in the left ventricle below the aortic valve, causing a pressure gradient across the obstruction within the ventricle.

tricuspid stenosis  (TS) narrowing or stricture of the tricuspid orifice of the heart.

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pyloric stenosis

n.

Narrowing of the gastric pylorus, especially by congenital muscular hypertrophy or by scarring resulting from a peptic ulcer.

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pyloric stenosis,

a narrowing of the pyloric sphincter at the outlet of the stomach, causing an obstruction that blocks the flow of food into the small intestine. The condition occurs as a congenital defect in 1 of 200 newborns and occasionally in older adults secondary to an ulcer or fibrosis at the outlet. Diagnosis is made in infants by the presence of forceful projectile vomiting and palpation of a hard, prominent pylorus and in adults by x-ray examinations after a barium meal. Surgical correction is done with the patient under light general anesthesia after the stomach is emptied. The muscle fibers of the outlet are cut, without severing the mucosa, to widen the opening. After surgery in adults, a stomach tube remains in place and observation is maintained for signs of hemorrhage or of blockage of the tube. See also pyloromyotomy.

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pyloric [pi-lor´ik]

pertaining to the pylorus or to the pyloric part of the stomach.

pyloric stenosis obstruction of the pyloric orifice of the stomach; it may be congenital, as in hypertrophic pyloric stenosis, or acquired, due to peptic ulceration or prepyloric carcinoma.

The initial symptom is vomiting, mild at first but becoming increasingly more forceful. It can occur both during and after feedings. Diagnosis may be confirmed by x-ray examination using a barium meal.

Treatment is usually surgical, involving longitudinal splitting of the muscle (pyloromyotomy).

Congenital pyloric stenosis. The abnormal narrowing of the opening of the pylorus causes episodes of projectile vomiting. From Frazier et al., 2000.

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stenosis

stĕ-no´sis

steno´ses

an abnormal narrowing or contraction of a body passage or opening; called also arctation, coarctation, and stricture.

aortic stenosis obstruction to the outflow of blood from the left ventricle into the aorta; in the majority of adult cases the etiology is degenerative calcific disease of the valve.

hypertrophic subaortic stenosis (idiopathic hypertrophic subaortic stenosis) a cardiomyopathy of unknown cause, in which the left ventricle is hypertrophied and the cavity is small; it is marked by obstruction to left ventricular outflow.

mitral stenosis a narrowing of the left atrioventricular orifice (mitral valve) due to inflammation and scarring; the cause is almost always rheumatic heart disease. Normally the leaflets open with each pulsation of the heart, allowing blood to flow from the left atrium into the left ventricle, and close as the ventricle fills again so that they prevent a backward flow of blood. In mitral stenosis there is a resultant increase of pressure in the pulmonary artery and hypertrophy of the left ventricle. The usual treatment is surgical replacement of the valve.

pulmonary stenosis (PS) narrowing of the opening between the pulmonary artery and the right ventricle.

pyloric stenosis see pyloric stenosis.

renal artery stenosis narrowing of one or both renal arteries by atherosclerosis or by fibrous dysplasia or hyperplasia, so that renal function is impaired (see ischemic nephropathy). Increased renin release by the affected kidney causes renovascular hypertension, and bilateral stenosis may result in chronic renal failure.

spinal stenosis narrowing of the vertebral canal, nerve root canals, or intervertebral foramina of the lumbar spine, caused by encroachment of bone upon the space; symptoms are caused by compression of the cauda equina and include pain, paresthesias, and neurogenic claudication. The condition may be either congenital or due to spinal degeneration.

subaortic stenosis aortic stenosis due to an obstructive lesion in the left ventricle below the aortic valve, causing a pressure gradient across the obstruction within the ventricle. See also idiopathic hypertrophic subaortic stenosis.

subglottic stenosis stenosis of the trachea below the glottis. A congenital form results in neonatal stridor or laryngotracheitis, often requiring tracheotomy but resolving with age. An acquired form is caused by repeated intubations.

tracheal stenosis scarring of the trachea with narrowing, usually as a result of injury from an artificial airway or trauma.

tricuspid stenosis (TS) narrowing or stricture of the tricuspid orifice of the heart, a condition often seen in patients with severe congestive heart failure, usually the result of volume overload and pulmonary hypertension with right ventricular and tricuspid annular dilation.

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pyloric stenosis

Congenital hypertrophic pyloric stenosis, hypertrophic pyloric stenosis GI disease A narrowing of the gastric outlet into the duodenum due to thickening of pyloric muscle, which controls gastric flow to the duodenum; PS is more common in ♂; Sx appear shortly after birth.