Transcript fetal cardiac intervention (FCI)

PRENATAL TREATMENT OF
CONGENITAL HEART DISEASE
By Dr. Bahar Dehghan
Pediatric Cardiologist
Isfahan University of Medical Sciences
Background
• It was postulated for many years prior to the
availability of ultrasound that certain congenital
cardiac malformations evolve through the course of
pregnancy.
• The potential benefits of fetal cardiac intervention
(FCI) have been realized for many years.
• In 1975: intrapartum treatment of fetal V.T
by administering propranolol to the mother.
• As early as 1986: in utero pacing for CHB in a
human fetus.
• Recently, however, interest in FCI has
accelerated.
• In 1992, Allan et al. reported an experience with
a percutaneous technique for fetal aortic
balloon valvuloplasty.
• Four fetuses were subjected to this technique,
with a single long-term survivor.
• That technique was devised against a
background of appalling survival figures for
neonates undergoing surgical treatment for that
lesion at that time.
• For conditions in which the fetus is at high risk
for prenatal or neonatal death, the rationale for
FCI is obvious, to improve survival.
• If death is not imminent but the disease is likely
to have major lifelong morbidity, the rationale is
that FCI will modify the course of cardiac
growth, function, and/or development in utero
sufficiently to alter postnatal outcome and
justify the potential risks of the procedure.
Indications
1. Aortic stenosis
2. Intact or restrictive atrial septum
3. Pulmonary atresia with intact ventricular
septum (PA-IVS)
4. Complete heart block with hydropse
Patient selection
• These defects have a spectrum of severity and
usually progress during gestation, so the ideal time
to treat them is before any additional insult is
incurred.
• The ideal gestational age: when the patient meets
criteria and as soon as possible.
• The ideal gestational age for treatment is therefore:
 between 18 and 30 wks’ gestation for aortic stenosis,
 with 22-30 wk preferred for pulmonary valve
procedures,
 up to 34 wk preferred for an atrial septal procedure
in the presence of left heart obstruction.
• Whether invasive confirmation of a normal
karyotype in the fetus is required is controversial.
• Noninvasive maternal serum testing should be
performed and the fetus found to be euploid before
intervention.
• Additionally, a detailed ultrasound examination should
be performed to define:
 other fetal anomalies
 placental location
 cervical length
 uterine or adnexal masses
that could influence the safety and technical aspects of the
procedure.
• A thorough evaluation of the maternal health and
obstetric history should be undertaken by an
experienced maternofetal medicine specialist to rule
out contraindications.
• The proposed procedure should also be discussed
with the referring obstetrician/perinatologist who
will be caring for the patient after the procedure.
• All patient counseling is preferably done with the
partner or support person(s) present, and every
effort should be made to ensure that there is an
understanding of the issues regarding the
procedure’s safety and efficacy for both the pregnant
woman and the fetus.
Contraindications
• Significant preexisting maternal disease or obstetric
comorbidity that would place the fetus or mother at
higher risk, including:
 anesthesia and the invasive procedure itself;
 a BMI exceeding 35 (relative contraindication);
 maternal communicable diseases such as HIV
infection,
 uncontrolled or pregestational diabetes (relative),
 history of cervical incompetence (relative),
 hematologic disorders that affect coagulation,
 Significant extracardiac pathology in the fetus
(significant chromosomal abnormality and structural
abnormalities other than the cardiac lesion),
 Multiple gestation (relative),
 Inability of the mother to provide informed consent.
Patient Preparation
• Maternal general anesthesia may be considered when a
laparotomy is planned.
• Regional spinal anesthetic is almost always preferred,
with additional IV sedation as needed for maternal
comfort.
• The choices of anesthesia are usually made on an
individual basis and depend on the medical and obstetric
factors present and on the institution's and team's
experience and preference.
• Once maternal anesthesia is achieved, the patient is
usually placed in a slight left lateral orientation.
• An ultrasound-guided technique using high-quality
portable equipment.
• Initially, the obstetric sonographer reassesses the
fetal lie to plan the optimal access site.
• Fetal movement may make these procedures technically
more difficult.
• Maternal anesthesia alone does not result in adequate
suppression of fetal activity; therefore, in most cases,
additional fetal anesthesia is administered:
 The usual choice of fetal anesthetic is fentanyl in
combination with pancuronium bromide injected into
the fetal gluteal region under US guidance.
Complications
• Isolated maternal anesthetic risks, however small,
depend on the mode of anesthetic used include
maternal cardiovascular compromise with
respiratory distress and pulmonary edema.
• Placental abruption and resultant maternal
hemodynamic compromise because of uterine
manipulation to achieve optimal fetal positioning.
• Preterm labor (10%), after the procedure with a
possible need for maternal hospital admission and
monitoring for implications of tocolysis.
• PROM (2% risk) may lead to a uterine infection, for
which maternal antibiotic therapy is required.
• Transient bradycardia (10-40%) due to needle puncture
of the fetal heart and needle manipulation during the
procedure.
• Severe sustained fetal bradycardia and dysfunction have
been noted, requiring intracardiac or IM resuscitative
medications.
• Hemopericardium, occasionally, pericardiocentesis is
necessary for impacting cardiac output.
• Intracardiac thrombus formation and loss of catheter
tip have also been reported.
• Higher incidence of fetal loss (10%) after the
procedure than for pregnancies continuing without
invasive intervention.
• Generally, there is no change in the mode of delivery
after cardiac surgery in utero, and delivery plans are
made on the basis of the usual obstetric indications.
Technical limitations or failures of fetal interventions
• Although it is evident that technical success is
possible for fetal aortic and pulmonary valvuloplasty
and atrial septoplasty, universal adoption of in-utero
treatment for all fetuses is not appropriate.
• The level of care both in the obstetric environment
and for NICU may not be available at all institutions.
• Currently, the practice of FCI is confined to a few
institutions that have invested a great deal of time
and effort in research, development, and refinement
of technical expertise in this area.
• Technical issues related to fetal positioning,
stabilization, and the need for continuous imaging by
specially trained personnel with experience in US
guidance of invasive procedures.
• Equipment-related limitations, including imaging
artifacts caused by the materials used to
manufacture the needles, wires, and catheters,
exacerbated by the diminutive sizes of the cardiac
structures being imaged.
Future directions
• Given the relative rarity of these fetal congenital
heart conditions, more collaborative effort is
necessary in order to improve our procedural
techniques and to achieve an acceptable safety level
for both the mother and fetus.
• It is also essential to continue efforts to improve
equipment technology for diagnostic imaging and in
the procedure room.
• One potentially important advance may come in the
form of sophisticated robot-guided FCI.
• Fetal therapy for congenital heart conditions is an
area that holds great promise in the management of
complex cardiac disease.
“Thank You For Your Attention”