Diagnostic ultrasound ( PDFDrive )

CHAPTER 37 The Fetal Heart 1293
Asplenia and Polysplenia:
Associated Findings
ASPLENIA
Absence of spleen
Bilateral right-sidedness
Right atrial isomerism
Bilateral trilobed lungs
Bilateral right bronchi and pulmonary arteries
Ipsilateral location of the aorta and IVC
Bilateral SVC
Situs ambiguous
Midline horizontal liver
POLYSPLENIA
Multiple spleens
Bilateral left-sidedness
Left atrial isomerism
Bilateral bilobed lungs
Bilateral left bronchi and pulmonary arteries
Interruption of IVC
Azygous continuation of IVC
Situs ambiguous
Midline horizontal liver
Congenital heart disease
Complete atrioventricular block
IVC, Inferior vena cava; SVC, superior vena cava.
let ventricle, mitral stenosis, cor triatriatum, dextrocardia, right
atrial hypoplasia, AVSD, truncus arteriosus, and TOF have also
been observed. 184-188 Complete A-V block with an AVSD is
associated with polysplenia. Polysplenia syndrome is the second
most common disease associated with fetal heart block (ater
L-TGA). 186
Cardiosplenic syndromes should be considered when CHD
occurs with an arrhythmia. If these syndromes are suspected, a
careful search is made for the fetal spleen, which has been
visualized at 20 weeks’ gestation, with careful consideration of
the location of the fetal stomach. 186,189 Other abnormal relationships,
such as ipsilateral aorta and IVC (associated with asplenia)
or interruption of the IVC with continuation of the azygous vein
(associated with polysplenia), may be documented prenatally.
he mortality rate with cardiosplenic syndromes is extremely
high. Treatment depends largely on the type and number of
associated anomalies. Because cardiac malformations associated
with polysplenia are oten less severe, they are more amenable
to surgical correction than lesions associated with asplenia. 189,190
Neonates with asplenia have a higher mortality and postoperative
morbidity because of the high frequency of associated complex
cardiac malformations. In polysplenia the greatest attrition occurs
in the prenatal period and is oten related to heart block with
resultant hydrops. 188
Cardiac Tumors
Fetal cardiac tumors are rare. Approximately 10% are malignant.
191,192 Until the infant is 1 year of age, the majority of cardiac
RV
RA
LV
LA
R
FIG. 37.39 Rhabdomyoma. Apical four-chamber view shows an
echogenic mass in the left ventricle (LV), consistent with a rhabdomyoma
(R). LA, Left atrium; RA, right atrium; RV, right ventricle.
and pericardial masses are rhabdomyomas (58%) and teratomas
(19%). Cardiac ibromas account for approximately 12% of the
tumors in this age group. Other, less frequent tumors include
mesothelioma of the A-V node and cardiac hemangioma
(approximately 2% each).
Sonographically, fetal cardiac rhabdomyomas appear as solid,
echogenic masses. Rhabdomyomas (cardiac hamartomas) are
usually multiple, typically arising from the interventricular
septum 193-199 (Fig. 37.39). Rhabdomyomas may develop in utero
ater an initially normal fetal echocardiogram and may increase
in size and number over time. 29,196,200-202 his inding underscores
the importance of serial fetal echocardiograms in fetuses at risk
for rhabdomyomas.
Of patients with cardiac rhabdomyomas, 30% to 78% have
tuberous sclerosis. 193-195 Other signs of tuberous sclerosis are
rarely found in fetal life, with the exception of subependymal
tubers in the brain, which can be detected with fetal MRI or by
mass efect leading to hydrocephalus. 193 Unfortunately, the absence
of cardiac neoplasms in a fetus at risk for tuberous sclerosis does
not exclude this diagnosis. 196
Cardiac tumors become hemodynamically signiicant by
causing obstruction to the outlow tracts or A-V valves, resulting
in congestive heart failure, hydrops, pericardial efusion, and
arrhythmias. 193 Prognosis depends on the size, number,
and location of the tumor as well as associated arrhythmias and
anomalies. A meta-analysis of 138 published cases of fetal cardiac
rhabdomyomas found that size greater than 20 mm, presence
of arrhythmia, and hydrops were signiicantly associated with
increased morbidity. 200 Infants with cardiac rhabdomyomas have
a guarded prognosis. Rhabdomyomas are hormone-sensitive
neoplasms, which explains their tendency to spontaneously
regress. 203 Clinical manifestations associated with fetal cardiac
rhabdomyomas are diverse, ranging from spontaneous regression
of the tumor to sudden death. 192 Ater birth, the cells lose the