| Discussion: HETEROTAXY SYNDROME - Also known as situs ambiguous - Refers to visceral malposition and dysmorphism associated with indeterminate atrial arrangement - Associated with mutations in CFC1 gene, encoding CRYPTIC protein, on chromosome 2
TYPES - Heterotaxy with asplenia (ie, right isomerism or bilateral right-sidedness) Both lungs have three lobes and eparterial bronchi [main bronchus located superior to ipsilateral main pulmonary artery]
- Heterotaxy with polysplenia (ie, left isomerism or bilateral left-sidedness) Both lungs have two lobes and hyparterial bronchi [main bronchus passes inferior to ipsilateral main pulmonary artery]
Incidence of associated anomalies include: - congenital heart disease in patients with heterotaxy ranges from 50% to nearly 100% - Malrotation is a frequent finding (89% in one study); 60% present by 1 month, 90% by 1 year Therefore, imaging evaluation should include chest radiography, echocardiography, abdominal US, and upper GI series Avoid delays when malrotation is diagnosed even if patient is asymptomatic
MALROTATION Occurs in 1 in 500 live births Male predominance of at least 2:1 Approximately 75% will eventually develop volvulus, and 75% of those will present within the first month of life Mortality of rate for malrotation with volvulus is between 3% and 15%
PATHOPHYSIOLOGY - Normal intestinal rotation - duodenojejunal junction rotates to Left, 270° counterclockwise - results in retroperitoneal duodenum anchored in LUQ at ligament of Treitz - cecum rotates to Right, 270° counterclockwise - results in RLQ cecum
Malrotation = incomplete rotation - interruption at any point in process
CLINICAL PRESENTATION - Hallmark of presentation: bilious emesis - Classic: infant with sudden onset bilious emesis and abdominal distention - Atypical/chronic: unimpressive vague abdominal pain or intermittent nonbilious vomiting - Late: chronic abdominal pain, acute duodenal obstruction, chronic diarrhea, malabsorption, FTT - Adults: long history of intermittent abdominal pain, acute severe abdominal pain, bowel obstruction
DIFFERENTIAL DIAGNOSIS - Malrotation with volvulus - Duodenal atresia - Jejunoileal atresia - Necrotizing enterocolitis (NEC) - Meconium ileus - Hypertrophic pyloric stenosis (HPS)
DIAGNOSTIC RADIOLOGY - Abdominal plain film Upper GI is the examination of choice Barium enema
Diagnosis can sometimes be made on Ultrasound and CT, however these are not the indicated studies
COMPLICATIONS OF MALROTATION - Obstruction - Midgut volvulus - Peritoneal (Ladd) bands - Internal hernia - Hypoproteinemic gastroenteropathy - Melena secondary to bleeding from mesenteric intramural varices - Sepsis secondary to mucosal necrosis
RISK FACTORS FOR MALROTATION - Congenital diaphragmatic hernia -Abdominal wall defects -Duodenal atresia -Prune-belly syndrome -Heterotaxy syndrome with asplenia/polysplenia
TREATMENT - Emergent consult with pediatric surgeon
PROGNOSIS - Excellent when operation performed in timely manner - Short gut syndrome = high morbidity
Operation - Ladd’s procedure with appendectomy |