Module 8 : Fetal GI Pathology Flashcards
what 7 things should and ultrasound survey of the GI tract include
- intact abdominal wall
- normal situs
- normal cord insertion
- skin thickness
- fluid collections
- appropriate size for dates
- bowel echogenicity
what is special about the abdominal circumference measurement
- it is the most accurate measurement for dates
4 abdominal wall abnormalities
- omphalocele
- gastroschisis
- body stalk anomaly
- bladder and cloacal exstrophy
what is the normal physiological mid gut herniation and when does it occur
- gut herniates outside fetal abdominal cavity and rotates 90º and returns back into the cavity
- starts 8 weeks ends 12 weeks
what is an omphalocele
- defect at the base of the cord
- abdominal contents herniate into the umbilical cord
- covered by a membrane
+ peritoneum and amnion - may contain bowel stomach and liver
what lab value will be increased with an omphalocele
- MSAFP increased
what does a small omphalocele containing only bowel usually have an association with
- a high association with have a chromosomal abnormality
what three things is a large omphalocele associated with
- beckwith Wiedemann
- pentalogy of cantrell
- trisomy 18
what is the prognosis of omphalocele
- depends on associated abnormalities
- would need surgery to correct
what trisomy’s are most commonly associated with omphalocele
- trisomy 18 and 13
what three other diseases are seen with omhpalocele
- trisomy 21
- 45 XO
- triploidy
what 5 things does the monographer need to establish when scanning omphalocelel
- is there a membrane surrounding contents
- is the cord at the center of the fetal abdomen
- contents seen within the omphalocele
- presence of ascites
- other associated anomalies
how to measure AC with omphalocele
- exclude herniation
what is gastroschisis
- a defect in the abdominal wall to the RIGHT of the umbilical cord insertion
- bowel is freely floating in the amniotic fluid
- NO COVERING MEMBRANE
- typically no other associated syndromes
what lab value will be increased with gastroschisis
- MSAFP increased
what is more common omphalocele or gastroschisis
- gastroshcisis
what 5 things increase chance of gastroschisis
- substance abuse
- some medication
- younger women
- smokers
- weed
do gastroschisis have a high stillbirth rate
- yes
- fetal assessments performed regularly
- BPP and NST
+ regardless of the BPP score NST is done
gastroschisis and sonography
- determine contents of herniated structures
- a small hole or defect may affect blood supply to herniated structures
- severe pulling may cause ascites, perforation which can lead to MECONIUM PERITONITIS
- a ruptured omphalocele can mimic gastroschisis
- measure bowel diameter for follow up
how is gastroschisis treated
- silo treatment
+ water in bag pushes the bowel back into the abdomen - no surgery required
what is a body stalk anomaly
- consists of 2/3 of these anomalies
+ myelomeningocele or caudal regression
+ thoraabdominoschisis or abdominoschisis
+ limb defects - aka limb-body-wall complex
7 sonographic features of body stalk anomaly
- missing limbs or club feet
- abdominal contents may be outside body cavity and free or attached to placenta
- myelomeningocele with associated Arnold chiari malformation
- ectopic corgis or other heart defects
- facial cleft may be present
- CORD SHORT OR ABSENT
- low fluid
what is bladder exstrophy
- caused by defect in development of cloacal membrane
- failure of closure of the bladder, lower urinary tract, overlying symphysis pubis, rectus muscles and skin
- sporadic
what lab value will be increased with bladder exstrophy
- MSAFP increased
4 sonographic signs
- ABSENT BLADDER WITH A SOFT TISSUE ANTERIOR MASS
- low umbilical cord insertion
- malformed genitalia
- may be mistaken for omphalocele
what 4 anomalies does cloacal exstrophy include
- bladder exstrophy
- omphalocele
- imperforate anus
- spina bifida
what two structures develop from the cloaca
- the urogenital sinus
- rectum
three fetal GI obstructions
- atresia or stenosis \+ esophageal \+ duodenal - meconium ileus - meconium peritonitis
what is esophageal atresia
- absence of a segment of the esophagus
- usually associated with tracheoesophageal fistula
- unknown etiology
- ESOPHAGUS ACTUALLY STOPS
sonographic features of esophageal atresia
- small or absent stomach \+ depends on if the fistula connects back to stomach - polyhydramnios - dilated proximal esophagus in neck - fetal vomitting
what 3 other anomalies are associated with esophageal atresia
- VACTERL
- trisomy
- heart defects
what is duodenal atresia
- common small bowel obstruction
ultrasound appearance of duodenal atresia
- 2 stomach
+ stomach and first portion of duodenum - double bubble
- polyhradmnios
what 3 other anomalies is 50% duodenal atresia associated with
- cardiovascular
- trisomy 21
- other bowel abnormalities
does dilated small bowel have peristalsis or no
- yes it does
does dilated large bowel have peristalsis or no
- does not have peristalsis
colon diameter in a term fetus
< 18mm
small bowel diameter in a term fetus
< 12mm
what is a Volvos
- bowel twisting on its own blood supply
what is meconium ileus
- obstruction of small bowel with meconium
- almost exclusively due to cystic fibrosis
what is the sonographic appearance of meconium ileus
- echogenic bowel
how do we asses echogenic bowel on ultrasound
- echogenic bowel should be as echogenic as bone
- decrease gains to see which disappears first bowel or bone
- if bowel still visible after bone disappears then diagnosis is made
- WATCH TRANSDUCER FREQUENCY IS OVER 5MHZ THEN NORMAL BOWEL WILL BE HYPERECHOIC
- USE SPLIT SCREEN FOR COMPARISON
what 4 things is echogenic bowel associated with
- cystic fibrosis
- chromosomal abnormalities
- TORCH infection from mother
- meconium peritonitis
what is meconium peritonitis
- a bowel obstruction can lead to perforation of bowel
- perforation leads to contents of fetal bowel (meconium) leaking out into the peritoneum
- this causes inflammation o the peritoneum
- appears as echogenic reflectors throughout the bowel
what is an umbilical vein vary
- dilation of umbilical vein after it enters the fetal abdomen
- increase risk of thrombus in umbilical vein
what is a persistent right umbilical vein
- during early embyrogenisis there are 2 umbilical veins
- right umbilical vein travels along the right side of the gallbladder and turns toward the stomach instead of away
what three things may cause hepatic calcification
- TORCH (maternal infection)
- emboli
- ischemic damage of liver tissue and necrosis
sonographic appearance of hepatic calcification
- echogenic or hyperechoic focus that may have a shadow as well
4 origins of abdominal cysts
- mesenteric or omental
- ovarian if fetus is female
- choledochal cyst on the fetal CBD
- hepatic
sonographic appearance of abdominal cysts
- anechoic structure with through transmission and thin walls
3 other abdominal abnormalities
- echogenic debris within the stomach
- gallstones
- hepatic calcifications
echogenic debris within the stomach characteristics
- usually idiopathic and not ominous sign
- can be seen after amniocentesis (fetus swallowing blood)
- also seen when intrauterine bleeding has occurred
