general surgery(三) Department of Pediatrics Soochow University Affiliated Children’s Hospital
Pyloric stenosis Definition Infantile hypertrophic pyloric stenosis (IHPS) is a common surgical condition encountered in early infancy, occurring in 2–3 per 1,000 live births.
Pyloric stenosis Definition It is characterized by hypertrophy of the circular muscle, causing pyloric narrowing and elongation and producing partial or complete luminal occlusion. The incidence of the disease varies widely with geographic location, season, and ethnic origin. Boys are affected four times more than girls.
Pyloric stenosis Description The appearance of the pylorus in IHPS is that of an enlarged, pale muscle mass usually measuring 2 to 2.5 cm in length and 1 to 1.5 cm in diameter.
Pyloric stenosis Description Histologically the mucosa and adventitia are normal. There is marked muscle hypertrophy primarily involving the circular layer, which produces partial or complete luminal occlusion
Pyloric stenosis symptoms • The usual onset of symptoms occurs between 2 and 8 weeks of age with peak occurrence at 3–5 weeks of age. • It has been rarely reported in premature infants, especially extremely low birth weight infants, and these premature infants with IHPS present the signs and symptoms 2–4 weeks later as compared to normal term infants.
Pyloric stenosis symptoms • The clinical features vary with the • length of symptoms. Initially the vomiting may not be frequent and forceful, but over several days it progresses to every feeding and becomes forceful nonbilious vomiting described as “projectile”. • The emesis consists of gastric contents, which may become blood tinged with protracted vomiting and likely related to gastritis, with “coffee-ground” appearance (17–18% of cases).
Pyloric stenosis symptoms • Infants with IHPS do not appear ill or febrile in the early stages. • A significant delay in diagnosis leads to severe dehydration and weight loss due to inadequate fluid and calorie intake. • Severe starvation can exacerbate diminished glucoronyl transferase activity and jaundice associated with indirect hyperbilirubimemia as seen in 2–5% of infants with IHPS.
Pyloric stenosis symptoms • It should be possible to diagnose IHPS on clinical features alone in 80–90% of infants. The important diagnostic features are visible gastric peristaltic waves in the left upper abdomen and a palpable enlarged pylorus (“olive” like mass).
Pyloric stenosis Diagnosis cardinal features of IHPS: • no bilious projectile vomiting • visible peristaltic waves in the left upper abdomen • Hypochloremic,hypokalemic metabolic alkalosis
Pyloric stenosis Diagnosis Ultrasonography has become the most common imaging technique for the diagnosis of IHPS under optimal circumstances, this technique can be reliable.
Pyloric stenosis Diagnosis The most commonly used criteria for a positive ultrasound study: • a pyloric muscle thickness of 4 mm or more • a pyloric channel length of 16 mm or more
Pyloric stenosis Diagnosis A barium upper gastrointestinal (UGI) examination is highly effective in making the diagnosis of IHPS and should demonstrate an elongated pyloric channel and indentation on the antral outline, which are indirect findings of pyloric muscle enlargement .
Barium meal study of IHPS. Narrowed elongated pyloric canal giving a “string” or “double track” sign caused by compressed invaginated folds of mucosa in the pyloric canal
Pyloric stenosis Treatment Pyloric stenosis can be cured with a surgical procedure called a pyloromyotomy.
INTUSSUSCEPTIONDEFINITION • Intussusception is the most common cause of intestinal obstruction in children between 3 months and 6 years of age. It occurs when a portion of the bowel "telescopes" into itself, causing intestinal obstruction.
Intussusception occurs most commonly in infants between 15 and 19 months of age with only 10–25% of cases occurring after 2 years of age. • Although 90% of intussusceptions occur in children between 3 months to 3 years of age, it has also been reported in utero, in neonates, and in adults.
INTUSSUSCEPTION EPIDEMIOLOGY • Incidence 2 - 4 / 1000 live births • Usual age group 3 months - 3 years • Greatest incidence 6-12 months • Male predominance (1.5-2 : 1) • No clear hereditary association • No seasonal distribution • Frequently preceded by viral infection • URI, ADENOVIRUS
INTUSSUSCEPTIONPATHOPHYSIOLOGY • Precipitating mechanism unknown • Obstruction of intussusceptum mesentery • Venous and lymphatic obstruction • Third spacing of fluid into bowel wall • Ischemic necrosis occurs in both intussusceptum and intussuscipiens • Pathologic bacterial translocation
When older children develop intussusception, it is usually due to what is referred to as a pathologic lead point. A lead point is a recognizable anatomic abnormality that obstructs the bowel, thus initiating the process of intussusception. Meckel's diverticulum and lymphoma of the intestine are two classic examples of lead points. Intestinal tumors and polyps may also act as lead points. A pathologic lead point
INTUSSUSCEPTIONCLINICAL CHARACTERISTICS • The clinical presentation is more typical in infants and is characterized by episodes of abdominal colic associated with drawing up the legs and crying. • These episodes occur in 15–30 min intervals. In between episodes the infant is quiet. • Initially there may be vomiting of undigested food and streaks of blood in the stools.
INTUSSUSCEPTIONCLINICAL CHARACTERISTICS • Subsequently the child becomes lethargic between episodes, develops increasing abdominal distension, bilious vomiting, and passage of red currant jelly stools. • Often these symptoms are preceded by an episode of diarrheal illness. Sometimes there is a history of change in diet with introduction of weaning foods.
INTUSSUSCEPTIONPHYSICAL EVALUATION • On examination the child may be febrile and dehydrated with signs of shock in case of bowel ischemia. A curved sausage-shaped mass can be palpated anywhere in the abdomen when the infant is quiet. • Rectal exam is positive for blood in 60–90% of cases. Rarely a cervix-shaped mass is seen protruding beyond the anal verge.
INTUSSUSCEPTION • The classic triad of incessant cry due to abdominal colic, red currant jelly stools, and a palpable abdominal mass has been reported in 20–60% of cases.
INTUSSUSCEPTION • Ultrasonography of the abdomen is often diagnostic for intussusception with a reported accuracy of up to 100% (Fig). • The characteristic “target sign” is described as two rings of low echogenicity with an intervening hyperechoic ring similar to a donut. The edematous walls of the intussusception appear as superimposed hyperechoic and hypoechoic layers described as the pseudo-kidney sign.
INTUSSUSCEPTIONTREATMENT • The initial management of children with intussusception begins with fluid resuscitation in the emergency room. • The correction of dehydration is crucial before attempting reduction. • Nasogastric decompression--argued that it is not indicated in children who do not present with vomiting. • Antibiotic prophylaxis including anaerobic coverage is started.