Congenital visceral malformations

Question 1

Anal atresia

Answer 1

Definition: sporadically occurring malformation of the rectum with absence of an anal opening
Epidemiology
Associated conditions
Down syndrome, VACTERL syndrome
Clinical features
Flat bottom (no or poorly developed midline groove between buttocks), absence of anal opening
Thin anal membrane in place of anal opening through which meconium is visible
obstipation and ileus; fistulas
Diagnosis
Clinical diagnosis
Lateral pelvic radiography to determine position of the rectal pouch
Fistula screening
Examination of the genital area and the urethra
Investigation of additional malformations (e.g., spinal ultrasonography, sacral x-ray)
Treatment
IV hydration, no oral feeding
Anal reconstructive surgery

Question 2

Omphalocele

Answer 2

Definition: congenital herniation of abdominal viscera through the abdominal wall at the umbilicus; the hernia sac is covered by the amniotic membrane and the peritoneum
Pathophysiology: failed return of the midgut to the abdominal cavity
Epidemiology
♂ > ♀
trisomies (trisomy 21, trisomy 13); Beckwith-Wiedemann syndrome; often associated with additional malformations (cardiac, gastrointestinal)
Clinical features
premature infants
Umbilical hernia sac (may contain intestine, liver, and gall bladder)
Diagnosis
clinical diagnosis at birth!
Can be detected prenatally
Ultrasonography: polyhydramnios in utero
Elevation of maternal serum alpha-fetoprotein (MSAFP)
Complications: rupture of hernia sac with infection (peritonitis)
Treatment
Cesarean section to prevent rupture of the sac
Wrapping of the hernia sac with sterile saline dressings covered with plastic wrap
Nasogastric suction; IV fluids
Surgery (within the first 24 h of life)

Question 3

Gastroschisis

Answer 3

Definition: paraumbilical herniation of the intestine through the abdominal wall without formation of a hernia sac
Pathophysiology
bowel sections
additional anomalies are rarely present (in contrast to omphalocele)
Clinical features
Protrusion of intestinal content usually on the right side of the umbilicus; intestine not contained in a hernia sac
malabsorption
Peritonitis
especially in premature infants; associated with cryptorchidism and gastrointestinal stenoses or atresia
Diagnosis
clinical diagnosis
Can be detected prenatally (see “Diagnosis” of omphalocele above)
Treatment
Cesarean delivery has no advantage over vaginal delivery
Emergency surgery

Question 4

Biliary atresia

Answer 4

Definition: obliteration or discontinuity of the extrahepatic biliary system, most commonly of the common bile duct
Pathophysiology: obliteration or discontinuity of the biliary system → obstruction to bile flow (cholestasis) → secondary biliary cirrhosis and portal hypertension
Clinical features
Prolonged neonatal jaundice
Acholic stools, dark urine
Hepatomegaly
Diagnosis
conjugated hyperbilirubinemia; mild/moderate increase in aminotransferases and alkaline phosphatase, increased GGTP
Ultrasonography: absence of the gallbladder; no dilatation of the biliary tree
intraoperative cholangiography
Treatment
In cases of liver cirrhosis → liver transplantation (primary reason for liver transplantation in children)
Complications
If undetected: early biliary liver cirrhosis (at approx. 9 weeks of age!)