fetal ab wall

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occurs due to failure of the ab wall closing during fetal development and results in protrusion of th ebladder wall through the lower ab wall: bladder exstrophy
sono appearance is a normal urinary bladder not seen but a flattened soft tissue mass with (walls so thick that you cant see fluid w/i, exposed bladder mucosa is seen on the lower ab wall: bladder extrophy
prognosis depends on many factors, incl extent of defect and size of thorax to allow surgery to place heart back in chest; sono, hrt may be seen outside the thorax or bulging thru sternum; may be pericardial and pleural effusion: pentalogy of cantrell
no membrane covering mass; cord insertion to the left of the anomaly; bowel herniate, but stomach can as well; no assoc with other defects but may be associated with GI problems such as bowel obstruction: gastroschisis
ultrasound has proven to be a very effective tool in detecting anterior ab wall defects in utero. these defects occur during the __ trimester as the midgut elongates and migrates into the umbilical cord: 1st
the ___ usually returns to the ab cavity by the 11th wk. when this fails to occur, an ab wall defect is formed. the 2 most common defects are _ and _. less common are ectopia cordis, limb-body wall, cloacal exstrophy, & allantoic cyst: *midgut *omphalocele *gastroschisis
embryo is a flat disk consisting of 3 layers: ectoderm, endoderm, and mesoderm by __ week. in __ week, a process calle dfolding helps the embryo transform itself into a cylindrical shape and becomes becomes critical for ab wall closure: 5th, 6th
as the embryo folds at the cranial end, the base of the yolk sac is partially incorporated as the __, which later develops as the pharynx, lower respiratory system, esophagus, stomach, duodenum, liver, pancreas, gallbladder, and biliary duct system: foregut
growth of neural tube causes embryo to fold at caudally, incorporating part of the ys as the __, which turns into the cloaca (where bowel and urine come out before organs form. also causes the connecting stalk to move __ so allantois becomes part of uc: hindgut, ventrally
the derivative parts of ___are dist parts of trv, desc and sigmoid colon, rectum, sup part of anal canal, epithelium of the ur bld, and most of urethra. the sides of the embryo fold, leading to __and ant wall of embryo: hindgut, lateral
__ is primordium of small intestines(& most of duodenum), cecum, appendix, asc colon, and rt half to two thirds of the trvcolon. fusion of midline begins during __ week and finished by 8th wk: midgut, 7th
__ of the bowel occurs during the 8th wk of development as the midgut extends to the extraembryonic coelom in the prox portion of the uc. the midgut grows faster than the ab cavity at this stage because of the inc size of the liver & kidneys: umbilication hernia
it's very important to image the cord insertion site and the fetal ant. ab wall to evaluate for the presence of defects. the urinary bladder and pelvis are evaluated closely, the dx of bladder and __ exstropby also may be seen with US: cloacal
the following questions for ab wall defects should be answered (4): 1. what is the relation of the umbilical cord to the defect (inside or outside) 2. which organs are eviscerated? 3. is the bowel normal in appearance? 4. are other fetal malformations evident?
defects cause distortion of the normal contour of the ventral surface of the fetal abdomen. ab wall defects are the __ most common cause of AFP values.: 2nd
described as congenital defects that result in protrusion of the stomach or intestines through incomplete closures of the ab wall.: ab wall defects
three common ab wall defects. rarer ab wall defects include ectopia cordis, pentalogy of cantrell, amnion rupture sequence, and bladder and cloacal exstrophy: omphalocele, umbilical hernia(form of omphalocele), gastroschisis
midline defect characterized by the failure of the intestine in the umbilical cord to return to the ab region; occurs when there is a midline defect of the ab muscles, fascia, and skin results in herniation of intraab structures into the base of the u.c.: omphalocele
the AFP level may be slightly elevated or within normal limits if covered by skin; the prognosis varies according to the extent of the primary defect and associated structural and chromosomal abnormalities; isolated is better prognosis: omphalocele
two types of omphaloceles: __ and ___.: liver and bowel
contain liver w/i sac; represent a developmental defect in ab wall closure; affects ab wall muscles, fascia, and skin; may contain bowel and demonstrate a relatively largeab wall defects in comparison to ab diameter; can be linked to anomaly: liver omphalocele
contain a variable amount of bowel but no liver; have a higher risk for chromosomal abnormalities and other anomalies: bowel omphalocele
associated anomalies include complex cardiac disease, and GI, neural tube, GU anomalies, diaphragmatic hernias, and chromosomal anomalies; also associated with pentalogy of cantrell, and b-w syndrome: omphalocele
US : central ab wall defect w/evisceration of bowel or combo of liv and bowel into base of the u.c. color may aid in viewing continuity of u.c. into it; bowel ones appear echogenic and must be distinguished from umb hernia: omphaloceles
an opening in the layers of the ab wall with evisceration (herniation) of the bowel and , infrequentlyl, the stomach and GU organs; it is thought that it is a consequence of atrophy of the right umbilical vein or a disruption of the omphalomesenteric arts: gastroschisis
gastroschisis: defects are small (__ to __ cm) and are located next to the cord insertion; in the majority of cases, the defect is positioned to the __of the umbilical cord: *2-4 *right
small bowel is always found in the herniation; other organs that may be involved in the herniation include the large bowel, the stomach, occasionally portions of the GU system, and rarely the liver; assoc with amniotic band syndrome: gastroschisis
US appearance: right paraumbilical defect of the ab wall, rarely on left-side; free-floating herniated small bowel, large bowel, stomach, gallbladder, urinary bladder, and pelvic organs may be involved: gastroschisis
herniated bowel may be mildly dilated with bowel wall thickening (b/c irritated by af giving it chemical peritonitis); hydronephrosis, bladder deviation, and exstrophy may be observed: gastroschisis
membrane covering mass; cord inserts onto membrane; liver usually herniates, but bowel and stomach can as well; high association with congenital anomalies (trisomy 13 and 18): omphalocele
a group of disorders having in common the coexistence of an omphalocele, macroglossia, and visceromegaly: beckwith-wiedermann syndrome
; most cases are sporadic; sono it appears with omphalocele, macroglossia, diaphragmatic hernia, gigantis, hepatosplenomegaly, pancreatic hyperplasia, nephromegaly, cardiac anomalies, and hydramnios: beckwith-wiedermann syndrome
defect in the lower ab wall and ant wall of the ur bladder; turned inside out; maldevelopment of the lower ab wall leading to a rupture which causes the bladder to communicate with the af; bladder herniated outside wall more in pelvic region: bladder/cloacal exstrophy
rare severe form of bladder exstrophy; severe birth defect in which the bladder and intestines are exposed, causing the splitting of both male and female genitalia and the anus is occasionally sealed: cloacal exstrophy
the diagnosis involves a spectrum of anomalies of the lower ab wall, bladder, ant bony pelvis, and external genitalia; large pelvis because bones are splayed from the mass: cloacal exstrophy
US : similar to bladder exstrohy w/ exception of 2 exstrophied bladder units separated by intestine;2 hemi bladders w/ intestines in center; may be accomp by omphalocele, SUA, ascites, inguinal hernia, undesc testes, wide pelvis, vag/anal probs: cloacal exstrophy
rare; the association of two major defects: omphalocele and ectopic heart; the three other anomalies are the result of the these defects, involving a defect in the lower sternum, ant diaphragm, and diaphragmatic pericardium: pentology of cantrell
a collection of anomalies associatd with large cranial defect(exencephaly or encephalocele), facial cleft, body-wall defect involving the thorax, ab, or both, and limb defects; other anomalies include scoliosis and various internal malformations: limb-body wall complex
lt side body wall defects are 3 times more common than rt-sided ; sono it appears as a defect involving the ab and thorax; the eviscerated organs form a complex, bizarre-appearing mass entangled with membranes: limb-body wall complex
short umb cord can cause placental membranes to tear from ab wall causing __; like raschisis but on ant side: limb-body wall complex
ab organs: liv, biliary, spl, sto, esophagus, kids, &colon are well formed by the 2ndtri; umb arts and vns provide important anatomic __ for ab anatomy and meas. __ is open so allows conduit b/w umb and systemic vns.: *landmarks *ductus venosus
proportions of fetal body differ from adult; the fetal ab is larger compared with body length, and liv occupies larger vol of the ab. lt lobe is larger than rt; pelvic cavity is ___; therefore the ur bld and pelvic organs lie in ab: small
forms during the fourth week of gestation as the dorsal part of the yolk sac and incorporated into the embryo during folding; divided into three sections: primitive gut(foregut, midgut, hindgut)
derivatives of this are the pharynx, lower respiratory system, esophagus, stomach, part of the duodenum, liver and biliary apparatus, and pancreas: foregut
the esophagus is short in the beginning but it rapidly lengthens as the body grows, reaching its final length by the __ week. the ___ septum partitions the trachea from the esophagus: *seventh *tracheoesophageal septum
sto appears as a fusiform dilation of _part of foregut. duodenum devlops from caudal part of foregut & __ part of midgut. the 2parts grow and form a c-shaped loop and rotate to __ where portion of duodenum comes to lie in RP: *caudal *cranial *right
liver, gb, and bile ducts arise as bud from most _ part of the foregut in 4th wk; hematopoiesis begins during __ wk and accounts for large size of liv b/w the 7th and 9th wks. _ form from liv cells at 12 wks: *caudal *6th *bile
the pancreas develops from _ & _ panc buds of endodermal cells that arise caudally from foregut and are seen on each side of the duodenum; the ducts of the 2 buds join and combined duct becomes the main duct, __: *dorsal and ventral *wirsung
the wirsung duct of panc joins with _to enter duodenum: cbd
the spleen is a lymphatic organ that is derived from a mass of ___cells located between teh layers of the dorsal mesogastrium: mesenchymal
the midgut derivatives are the small intestines including most of the duodenum, the cecum and cloaca exstrophy, the ascending and most of trv colon. all of these structures are supplied by the __ and become encased by mesentery: SMA
while small bowel develops, asc and desc colon, duodenum, and pancreas become __. intestines form new line of attachment from duodedum to __: *retroperitoneum *ileocecal junction
the derivatives are the left part of the transverse colon, descending colon, sigmoid colon, rectum, sup portion of the anal canal, epithelium of the urinary bladder, and most of the urethra. all of thses structures are supplied by IMA: hindgut
the detection of the thoracic defect is important because many lesions may compromise fetal breathing and require surgery in the immediate neonatal period. the fetal thorax is examined by the sonographer in both the trv and __ or parasagittal planes.: coronal
lungs are __ so and increase from hypoechoic to hyperechoic with increased GA: homogenous
the ___serve as the lateral borders for the heart and lie superior to the diaphragm; seen sonographically, as an echogenic smooth hypoechoic muscular margin between the fetal liver or slpeen and th elungs: lungs
is normally slightly smaller than ab cavity; should be bell-shaped. int he presence of oligohydramnios, resultant pulmonary hypoplasia may be seen with reduction in overall thoracic size. __ meas are made in trv plane at the hrt level: *thoracic cavity *chest circumference
what is the chest circumference formula?: CC=(CA - HA) X 100/ CA
the central portion of the thorax is occupied by the __ with the majority of the heart positioned in the midline and left chest. the apex of the heart should be directed toward the __, whereas the base of the heart lies horizontal to the ___.: *mediastinum *spleen *diaphragm
the fetal lungs appear on sono as homogeneous and moderately __. early in gestation the lungs are similar to or slightly less echogenic than __. as gestation progresses, there is a trend toward increased pulmonary echogenicity relative to the liver.: *echogenic *liver
fetal breathing becomes most prominent in the 2nd and 3rd tri. mature fetus spends almost _ of its time breathing. breathing movements considered to be present if characteristic seesaw movements of the fetal chest or ab are sustained for _ s: *1/3 *20
most babies beyond_- __ wks should have fluid in sto; if no fluid is apparent, the stomach should be reevaluated in __ to __ minutes to rule out the possibility of cns problem (swallowing disorders), obstruction, oligohydramnios, or esophageal atresia: *14-16 weeks *20-30 minutes
movement of the gastric __ begins in fourth to fifth month; in the second trimester, this movement and fetal swallowing result in the delivery of increased a.f. volume distally into the small bowel and colon where fluid and nutrients are reabsorbed: *musculature
can be visualized in the thorax during the second and third trimesters as two or more parallel echogenic lines ("multilayered pattern"): esophagus
should be identified as a fluid-filled structure in luq; fluid should be anechoic in the normal fetus: stomach
liv, although involved in several congenital anolmalies, is rare affected by isolated hepatic ___. liv parenchyma cysts and _ have been reported; sono, most tumors appear hypoechoic solid masses w/i the liv, but may have cysts or calcs: *lesions *hemangiomas
color may be used to outline the __ pattern w/i the lungs (not a lot of blood there but should still see pulmo vessels. US can't tell if lungs are mature by looking at lungs. must look at _ instead: *vascular *placenta
most common malformation of midgut; remnant of prox part of yolk stalk which fails to degenerate and disappear during the early fetal per; usually smal fingerlike sac, about 5 cm long, and projects from border of the ileum; doesn't cause problems: meckel's diverticulum
duodenal atresia; most cases are found distal to __ and often coexist with __ pancreas (when pancreas wraps around duodenum like a belt): *ampulla *annular
in early gestation (10-20 weeks) the small bowel __is quite difficult to demonstrate; the region of the small bowel can be seen as it is slightly hyperechoic, as compared to the liver, and may appear "__" in the ab and pelvis;: *lumen *mass-like
hyperechoic appearance of small bowel persists thru/o pregnancy; as preg progresses, echogenicity dec adn small bowel located more centrally than colon. _ after 27 wks: peristalsis
when the intestines return normally to ab cavity and then herniate either pre or postnatally thru inadequately closed umbilicus; differs from omphalocele in that the protruding mass (omentum or bowel loop) is covered by subcutaneous tissue &skin: umbilical hernia
anolies may be detected sonographically within this organ; cholelithiasis may be identified when calcifications are found; these stones usually resolve spontaneously in utero or in the childhood period: gallbladder
seen near the end of the second trimester as a long tubular hypoechoic structure with well-defined wall;s the haustral fold help to differentiate it; more peripheral than small bowel; does not have peristalsis: large bowel; colon
the fetal __ is relatively large compared to the other intraabdominal organs. the normal gallbladder may be seen sonographically after __ weeks; both the gallbladder and __ appear as oblong fluid-filled structures on the transverse view: *liver *20 *portal/umbilical vein
__has been seen in utero but is more hard to recognize routinely b/c of lack of fatty tissue w/i gland; the __ is homogeneous in texture, isoechoic to the kids and slightly less echogenic than liv ; inc in size during gestation: *pancreas *spleen
presents as a total reversal of the thoracic and ab organs or as partial reversal (mirror image of some organs);the cause is unclear but it si thought to occur early in embryogenesis before normal laterality determination (before 3 weeks): situs inversus
__ is more severe than total situs inversus and may develop in two different combos of organ reversals; the stomach may or may not be reversed: partial situs inversus
two forms of partial situs inversus: asplenia and polysplenia
occurs with more severe form; absence of the spleen, abnormal positioning of the liver and gb (more midline) and abnormal postitioning fo the aorta and ivc on the same side: aspenia partial situs inversus
is represented as transposition of the liver and stomach, absence of the gb, and disruption of the ivc; at least two spleens are present along the greater curvature of the stomach (which is on the right side): polysplenia partial situs inversus
true kind is identified within the peritoneal recesses, whereas the pseudo kind is always confined to an anterior or anterolateral aspect of the fetal ab: ascites
is abnormal; fluid collections between the two leaves of unfused omentum, resulting in cyst- like appearance in the ab; when associated with fetal hydrops, pleural effusions, and pericardial effusion, integumentary edema is often observed: ascites
really looking at muscles seen along anterior wall or anterolateral wall: pseudoascites
dilation of the bile duct; don't confuse with stomach or mass;may be differentiated when a cystic mass is identified adjacent to the fetal stomach and gallbladder; may be confused with malformation of the stomach or bowel or duodenal atresia: choledochal cyst
a congenital blockage of the esophagus resulting from the faulty separation of the foregut into its respiratory and digestive parts; most common form occurs in conjuction with a fistula communicating b/w trachea and esophagus (tracheoesophageal fistula): esophageal atresia
in some instances, a fistula is not present, and fluid will not reach the stomach; hence the stomach will nor be visualized by u.s.; will not be differentiated int eh majority of cases because of a tracheoesophageal fistula: esophageal atresia
coexisting anomalies are seen; most common is anorectal atresia (others include vert & hrt defects, and renal and limb anomalies VACTERL); tri 18 and 21 are reported in assoc; prog depends on anomalies; VACTERL alone is repairable: esophageal atresia
sonographically absent of the stomach and polyhydramnios is seen: esophageal atresia
what is VACTERL: (more than one) vertebrae, anal atresia, cardiac anomalies, TracheoEsophageal atresia, renal anomalies, limb anomalies
2 cysts must be next to each other in order to dx; blockage of duodenal by a membrane that prohibits the passage of swallowed a.f.; atresia or narrowing of the bowel segment below blockage occurs; the amniotic fluid fails to move beyond blockage: duodenal atresia
two echo-free structures are found in the upper fetal abdomen and communicate; amniotic fluid afp values are commonly elevated in fetuses because of faulty swallowing: duodenal atresia
associated with multiple anomalies including trisomy 21, cardiovascular anomalies, gu anomalies, gi abnormalities, and iugr; prognosis is good, with immediate surgery after birth to connect the stomach to the jejunum, thus bypassing the obstruction: duodenal atresia
sono, a double bubble is seen representing a dilated stomach and duodenum; polyhydramnios is almost always seen later in pregnancy: duodenal atresia
3 or more structures dilated; blockage of the jejunum and ileal bowel segments; the entire length of the bowel is subject to obstruction; thought to be secondary to a vascular accident, either sporadic or secondary to volvulus or gastroschisis: jejunal-ileal atresia
the causes of small bowel obstruction include malrotation, atresias, volvulus, peritoneal bands, and cystic fibrosis; the dilated bowel loops may be isolated or associated with other anomalies, ascites, or meconium peritonitis: jejunal-ileal atresia
sono, it appears as multiple cystic structures (more than 2) within the fetal ab; hydramnios is present; suspected when clear cystic structures are found in pelvis: jejunal-ileal atresia
most common cause is cf; small-bowel disorder marked by thick meconium in dilated distal ileum; mucus built up in body; the earliest manifestation of cf, and is 3rd most common form of neonatal bowel obstruction after atresia and malrotation: meconium ileus
meconium begins to accumulate in the fetal ab int eh second trimester, at which time it can be seen on sonography as tiny echogenic reflections withint he perstaltic small bowel: meconium ileus
sono, echogenic bowel is seen in the lower ab region with dilation of the ileus; pseudocyst may develop: meconium ileus
disorder of bowel and gu tract; imperforate anus is a disorder that occurs when a membrane covers the anus, prohibiting expulsion of meconium; may be part of VACTERL or in caudal regression; prognosis poor b/c bowel and bladder incontinence: anorectal atresia
sono, dilated colon and calcified meconium are seen; amniotic fluid is typically normal or may be decreased when there are assoc. renal problems: anorectal atresia
a congenital disorder in which there is abnormal innervation of the large intestine; difficult to differentiate prenatally but may be suspected when dilated bowel loops are observed; etiology is sporadic or assoc. with trisomy 21: hirschsprung disease
sono, it mimics anorectal atresia; polyhydramnios and dilated bowel loops can help dx: hirschsprung disease
secondary to bowel perforation by some other structure; this condition may arise when the fetus has a sterile chemical peritonitis secondary to in utero bowel perforation: meconium peritonitis
sono, calcs are seen on the peritoneal surfaces or in the scrotum via the processus vaginalis; the ascitic fluid may also be echogenic b/c has meconium in it; dilated bowel loops; hydramnios is present; calcification or thick-walled, irregular cyst: meconium peritonitis
echogenic bowel, typically seen in 2nd tri; causes may be dec water content, alterations to meconium, or both; the dec water content may be 2ndary to hypoperistalsis, given that fluid is normally resorbed by small bowel, assoc w/ tri 21: hyperechoic bowel
the significance varies with its location in the small bowel or colon, menstrual age, and degree of echogenicity: hyperechoic bowel
3 grades of hyperechoic bowel grade 1: mildly echogenic and typically __ grade 2: moderately echogenic and typically ___ grade 3: very echogenic, similar to that of __ structures: *diffuse *focal *bone
occurs w/ fusion of amnion and chorion; the amnion doens't cover uc normally (amn band syndrome)but extends as sheet from cord and in continuous w/ body wall and placenta; severe and lethal: limb-body wall complex
hard to dx becaue you see sto with most common type and gastric secretions contribute to full stomach: esophageal atresia
usually not known to be genetically transmitted, although there is a slight recurrence risk: gastroschisis
may be assic w/ intermittent biliary obstruction and severe biliary cirrhosis; early dxis important: choledochal cyst
swallowing is indicator of __. bpp used by many ob/gyns to assess well-being and uses this as a scoring factor: fetal breathing movements
fetal respiration may vary in response to maternal activities and substance ingestion; is stimulated by inc __ and decreased by __: *sugar *smoking
no peristalsis seen in _ and is located peripherally. will see meconium which is gray: colon
poor prognosis in non-immune hydrops; can be serous or have debris; always check thoracic cavity for fluid: ascites
a number of syndromes may be assoc w/ finding of narrow chest diameter inc thanatophoric dwarfism: asphyxiating thoracic dystrophy
not always intestines that protrude into u.c. can be other organs. can't dx <12 wks: omphalocele
after the 15th to 16th week, __ begins to accumulate in the distal part of the small intestine as a combo of desquamated cells, bile pigments, and mucoproteins: meconium
have been assoc with incest, but not necessarily an outcome; the total kind usually has a normal outcome: situs inversus
AFP levels are significantly higher compared w/ omphalocele b/c of the exposed bowel w/o a membrane; found more in males; prognosis is excellent w/ surgical repair w/i hrs of delivery: gastroschisis
location of the hrt is important to document in a routine sono, as the detection of abn position may indicate the presence of a chest mass, _, or cardiac malformation. r/o diaphragm hernia and pleural effusion, etc if hrt is on __ side. __ means on lt: *pleural effusion *left *dextrocardia
the normal shape of the thoracic cavity symmetrically __ shaped, with the ribs formng the lateral margins, the clavicles forming the upper margins, and the diaphragms forming the lower margin: bell
lutreine and sewer before bowel and bladder forms: cloaca
the duodenum rotates to the __ in order for the two ducts of the pancreas to join together: rigth

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