<h1>Hypertrophic pyloric stenosis</h1>

Congenital disease, characterized by a thickening (hypertrophy) of the pyloric muscular layer, forming a obstacle in the way of the alimentary bolus between the stomach and duodenum

Incidence vary between countries: In Europe and North America there are 1-3 cases of hypertrophic pylric stenosis in1000 births. For the Asian and African populations the incidence is 1case of hypertrophic pyloric stenosis in 2000 births. There are 4 males affected by the disease for every 1 female affected. Also 1 in every 14 children whose parents suffered from the disease develop the disease. Given the data it results that the disease has a sex related genetic transmission pattern. 

What causes hypertrophic pyloric stenosis?

There are multiple theories as to what causes the disease:

1. Malformation theory: it states that the disease is caused by a delay in the development of the myenteric plexus, the pyloric tumor being present since birth
2. Spastic hypertrophy theory: the hypertrophy is caused by an abnormally increased  contraction of the pyloric muscle fibers. The increased contraction may be caused by an increased adrenaline secretion.
3. The endocrine theory: the disease is caused by an abnormal secretion of the suprarenal gland

Morphological changes in hypertrophic pyloric stenosis

The pylorus is enlarged with marked vascularization. Inside the lumen the mucosa is folded, edematous.
Section trough the pyloric region reveals a thickened pyloric musculature
 

Singns and symptoms of pyloric stenosis

Emesis at 3 weeks after birth, that are white and don't contain bile. Initial the emesis is in small amounts but after a few days explosive emesis that is projected over distance is present.
There is a growth stagnation and a decrese in body weight
Constipation and hyperchromatic urine are also present
The children is anxious and has a superficial respiration.
Signs of dehydration are also present: depresed fontanel, persistent skin folds, dry eyes
Abdominal examination is generally supple, with no pain upon palpation. Epigastric distention with visible peristaltic waves and palpation of the pyloric olive in the right hypochondriac region

Laboratory tests in pyloric stenosis

1. Increased hematocrit
2. Leucocytosis 
3. Increased levels of urea in blood
4. Metabolic alkalosis with: hypochloremia, hypokalemia and hyponatremia

Paraclinical investigations for pyloric stenosis

Ultrasonography of the abdomen with measurement of the pylorus wall length and wall thickness
Eso-gastric barium examination shows:

1. Filiform, elongated and medially situated pyloric canal 
2. Dilated stomach with increased peristalsis and excessive content
3. Persistence of barium in the stomach for more than 24 hours despite emesis

Clinical forms of pyloric stenosis

1. With manifestation within the first days after being born
2. Classic form, the most frequent,with onset 15-21 days after birth 
3. With late onset of symptoms 2-3 months after birth
4. Hemorrhagic form
5. Roviralta Syndrome

Differential diagnosis of pyloric stenosis

1. Regurgitation
2. Feeding mistakes
3. Intolerance to certain milk-derived products
4. Pyloric spasm
5. Debre-Fibije syndrome
6. Incomplete pre-pyloric diaphragm
7. Pyloric duplication
8. Emesis caused by infectious disease: septicemia, pneumonia, gastroenteritis, meningitis
9. Duodenal stenosis due to an incomplet diaphragm
10. Extrinsic stenosis situated either superior or inferior to the Vater's ampulla
11. Cardio-tuberositary malposition

Treatment of pyloric stenosis

Medical treatment

1. Frequent ingestion of milk in reduced amounts
2. Gastric lavage
3. Endovenous perfusion with glucose, physiological serum and vitamin K 
4. Antiseptics

Surgical treatment

Preoperatve reatment

1. Hydroelectrolitique and acido-basic reequlibration
2. Antibiotics
3. Gastric lavage 
4. Nasogastric intubation and aspiration

Surgery

1. General anesthesia with orotracheal intubation
2. Extramucosal pylorotomy Fedet-Weber_Ramstedt 
3. In case of lesion to the pyloric mucosa a Lamson procedure may be required 

Postoperative treatment

1. The toddler is put in an heated incubator, in lateral decubitus
2. Endovenous perfusion with glucose and electrolytes 
3. Hemogram
4. Resume of alimentation after 6-8 hours from the procedure
5. After3-4 growth normal growth is resumed 
6. Remove of the sutures in day 7 

Complications

1. Incomplete pylorotomy
2. Perforation of the stomach or duodenum
3. Pulmonary complications which lead to death of 1 in every 200 chilldren that have the disease

Followup

The main criteria are:

1. Resume of the normal digestive transit 
2. Resume of alimentary tolerance
3. Healing of the surgical wound 
4. Increase in body mass and resume of normal growth