Meconium peritonitis is a condition where perforation of the bowel due to a number of congenital pathologies, leads to the introduction of meconium into the peritoneal cavity. This causes a sterile inflammatory reaction.
Meconium peritonitis (MP) is a rare condition that results from the development of bowel obstruction in a growing fetus within the uterus. This may lead to perforation of the gut wall, which in turn leads to a leakage of meconium into the peritoneal cavity. Aseptic peritonitis ensues, due to a secondary inflammatory response. The outcome of MP depends to some extent on diagnostic and management approaches, which have greatly improved over the years  . Severity and symptomatology of the condition are determined by the gestational age of the fetus, at the time the perforation occurs.
There are many possible causes of bowel obstruction in utero. These range from vascular factors such as mesenteric ischemia, to bowel pathologies such as meconium ileus, intussusception, volvulus, intestinal atresia, Hirschsprung's disease, hernias, and meconium plugs . In addition to these, congenital infections, particularly parvovirus B19, rubella and cytomegalovirus, have been shown to be predisposing factors in the occurrence of MP . There is an established association between MP and cystic fibrosis . Polyhydramnios, jejunoileal atresia, and other gastrointestinal malformations have also been linked to MP.
There are three main classes of MP, the first being fibro-adhesive. This results in calcification and tissue deposition on the area of perforation, producing a mass that seals the defect. Most perforations are closed off before birth. The other types of MP are cystic and generalized. Additional effects of the inflammatory changes that may occur include ascites, fibrosis and intraperitoneal meconium calcifications.
Entire Body System
Neonatal Intestinal Obstruction
The water-soluble enema will also exclude other causes of neonatal intestinal obstruction. [clinicalgate.com]
Recurrent Urinary Tract Infection
After constructing a diversion colostomy, a cutaneous vesicostomy was necessary to prevent recurrent urinary tract infections. [ncbi.nlm.nih.gov]
Biliary atresia, malrotation, meconium peritonitis and transient hypothyroidism are occasionally seen in neonatal infants. [ncbi.nlm.nih.gov]
Six fetuses showed abdominal distension, bilious vomiting, and no normal meconium at birth; they underwent exploratory laparotomies and subsequently, survived and prospered. [ncbi.nlm.nih.gov]
vomiting Imaging Findings On conventional radiographs Meconium, being fluid density, is normally invisible on radiographs In meconium ileus, there may be dilated loops of bowel (small bowel) typically without air-fluid levels because of the viscosity [learningradiology.com]
Failure to pass meconium (stool) may lead to bilious vomiting and abdominal distention. [surgery4children.com]
Clinical presentation included abdominal distension, bilious vomiting, and failure to pass meconium. In two recent cases, prenatal ultrasonography detected a mass with proximal bowel distension indicative of cystic meconium peritonitis. [link.springer.com]
RESULTS: The prenatal US and/or MRI findings showed fetal ascites, a multicystic pelvic mass, oligohydramnios, and bilateral hydronephrosis in 5 of 11 patients with cloacal malformations. [ncbi.nlm.nih.gov]
Reduced Fetal Movement
The clinical utility of this report is the recognition that meconium peritonitis (MP) may be diagnosed in the acute phase with typical ultrasound features, and should be considered in the differential diagnoses of cases presented with reduced fetal movements [ncbi.nlm.nih.gov]
The diagnosis of meconium peritonitis can be made either in utero or after birth. Some features of the disease can spontaneously resolve before birth. It may be beneficial to test for cystic fibrosis, as there is a strong correlation between the two conditions.
During the prenatal period, imaging techniques are used to assess the fetal abdomen. These are:
- Ultrasound: A snowstorm appearance of the abdomen may be visualized, as well as focal calcifications that appear hyperechoic . Some of the other likely findings on ultrasound examination are fetal ascites, wide abdominal circumference and polyhydramnios . Distended bowel loops may also be present. The use of ultrasound may be instrumental in predicting the overall outcome of the newborn. Furthermore, information gained from imaging can predict the likelihood of surgery during the neonatal period. Some literature classifies ultrasound findings in MP into types I to III, which correspond to: massive ascites, giant pseudocysts and small pseudocysts or calcifications  . Types I and II were shown to be predictive of poor outcomes in the neonatal period. In addition, if such features persist, surgery is usually required in the postnatal period .
- Xray: This may show peritoneal or scrotal calcifications (in cases of a patent processus vaginalis), and an intraabdominal mass, which is often a meconium pseudocyst.
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