Fetal surgery involves procedures performed on fetuses while still in the uterus to treat conditions that could cause irreversible harm if left untreated. For a condition to be considered for fetal surgery, it must cause ongoing damage that can be mitigated by early intervention and occur before the fetus can survive outside the womb. Fetal surgery can be open or minimally invasive. Open fetal surgery requires general anesthesia for the mother and high concentrations of volatile anesthetic agents to achieve uterine relaxation, while minimally invasive techniques use local anesthesia. Proper maternal anesthesia management and fetal monitoring are needed to balance risks to the mother and fetus.

2.  Most fetal anomalies: Not appropriate for in
utero treatment
 Condition appropriate for fetal treatment must:
 Cause ongoing irreversible harm to the fetus
 Mitigated with early treatment &
 Occur before gestational age at which the
fetus could tolerate ex utero neonatal
intervention

3.  Most fetal anomalies are amenable to therapy
after birth however, sometimes therapy before
birth is desirable to prevent permanent organ
damage depending on the natural history and
pathophysiology of malformation
 Fetal surgery is a new and fast moving frontier
of medicine

4.  Procedures on the fetus or the placenta, with the
aim of altering the natural history of the disease
that is diagnosed in utero
 The first operation on a human fetus occurred in
1981 at the University of California San
Francisco

5.  Thorough maternal and fetal evaluation
 Open fetal surgery : GA
 Minimally invasive techniques: Local or neuraxial
anesthesia
 Anesthetic considerations : assoc with
nonobstetric surgery during pregnancy, planning
for fetal anesthesia & analgesia, fetal monitoring,
uterine relaxation, and postop fetal monitoring &
tocolysis

6.  Minimally invasive procedures
 FIGS-IT
 Fetoscopy/ Fetendo procedures
 Intrapartum procedures( EXIT)
 Open fetal surgery

10.  Minimally invasive approaches: Reduced risks
for preterm labor, delivery & uterine rupture
 Unlike in open fetal procedures: vaginal delivery
for this and future pregnancies
 Significant risk for preterm premature rupture of
membrane (PPROM), preterm labour

11.  Balancing the risks to both the mother and fetus
against the potential benefit to only the fetus
 Mother is the innocent bystander in the
endeavour her involvement involves only risk
 Major intervention to save the life of a fetus
warranted ONLY if maternal risks minimized
and good fetal outcomes assured

12.  Typical gestational ages for surgery are between
21 to 27 weeks
 Mid-gestational fetal surgery is performed for
twin-twin transfusion syndrome and the twin
reverse arterial perfusion syndrome (TRAP)

13.  Fetoscopic surgery: minimal insult to the uterus
while obtaining access to the fetus through
surgical trocar insertion or occasionally maternal
minilaparotomy
 LA / Epidural anaesthesia +/- IV sedation
 Used to treat TTTS and TRAP; Injection of
medication into the amniotic cavity or fetal blood
transfusions

14.  FIGS-IT procedures
 MAC with infiltration of LAs into the abdominal wall
 Additional opioid, BZD, or other anesthetic : for
maternal analgesia and anxiolysis
 Titrated to avoid deep sedation and the associated
increased risk for pulmonary aspiration of gastric
contents

15.  EXIT Procedures involves only partially
delivering the fetus, thereby uterine volume,
placental perfusion and oxygenation are
maintained (Placental bypass)
 Allows time to perform direct laryngoscopy,
bronchoscopy, intubation and tracheostomy on
the fetus

16.  For fetuses with known airway compromise or
obstruction, an EXIT procedure allows continued
fetal support by the intact uteroplacental unit
(placental bypass) while the fetal airway is
secured or other procedures completed
 Minimal chances of postnatal respiratory
compromise, hypoxia, & asphyxia

17.  ECMO can be initiated during an EXIT procedure for a
fetus with significant cardiopulmonary disease
 Fetal surgical procedure> 2.5 hours successfully
performed using placental bypass
 Congenital lesions treated with EXIT procedures include
cystic hygroma, lymphangioma, cervical teratomas,
Laryngeal webs and other congenital syndromes with
potential for airway compromise

18.  Complete uterine relaxation is necessary to
expose the operative fetal anatomy; additionally
the fetus has to be maintained inside the uterus
 Unlike open fetal surgery however, the fetus is
delivered at the end of the fetal intervention
resulting in a completely flaccid uterus that must
immediately involute or else massive maternal
hemorrhage will occur

19.  Open Fetal Surgery: Preoperative
management
 Drugs and approaches used to minimize
aspiration of gastric contents
 Uterine tocolytics (i.e., indomethacin) should be
given to the mother preoperatively
 Left displacement of gravid uterus

20. Open foetal surgery: Intraoperative mgmt
 GA with Endotracheal intubation; GA induced with a
rapid sequence technique
 Before maternal skin incision, conventional
concentrations of anesthetics administered to the
mother (∼1 MAC)
 Before skin incision, the inspired concentration of
volatiles is increased, and before uterine incision,
the concentration is further increased (≥2 MAC) to
provide profound uterine relaxation

21.  IV administration of NTG in doses up to 20
μg/kg/min has been used successfully
 This technique may have increased risk for
maternal pulmonary edema
 Use of NTG may affect fetal vascular tone,
resulting in alterations in CBF and increased
likelihood of fetal cerebral ischemia, as well as
intraventricular and periventricular hge

22.  Open foetal surgery: Postoperative mgmt
 Continue tocolytics (MgSO4/Indomethacin)
 Patient-controlled epidural analgesia
 Monitor uterine activity and fetal heart rate
 Ongoing fetal evaluation

23.  Maternal Factors
 CO increases by 50-100% ;BP drops by 15%
 The large uterus increases the risk of supine
hypotension syndrome
 Intravascular blood volume increases by 40%;
more than the RBC volume increase (20%) which
alters the plasma concentration (lower albumin
levels), thus altering the PK/PD of drugs

24.  Maternal Factors
 Higher O2 consumption and a lower FRC results
in rapid desaturation
 Airway mucosa is swollen and bleeds easily
making it difficult to intubate
 MAC values decrease by 40% : deeper level of
anesthesia than predicted during surgery with a
relative over dosage

25.  Maternal Factors
 Elevated gastric acid content, delayed emptying
and lower GE sphincter tone : All pregnant
women treated full stomach
 Epidural space is narrowed by the epidural
venous engorgement increasing the risk of
intravascular catheter placement and a larger
dermatomal spread of injected LAs

26.  Placental Factors
 Lipid soluble inhalation agents are not ionized and
of low molecular weight :readily cross the placenta.
Uptake slower in fetus than mother
 Fortunately ,fetal MAC is less than that of the
mother this is well below that needed to obtain
uterine relaxation: Adequate maternal anesthesia
and uterine relaxation results in adequate fetal
anesthesia

27.  Techniques used to prevent preterm labor
 Avoidance of intraoperative and postoperative uterine
contraction
 Open fetal surgery and the EXIT procedures profound
uterine relaxation required for optimal surgical exposure
 Volatile anesthetic agents at 2 MAC concentrations are
potent uterine relaxants
 These high concentrations leads to reduction in cardiac
output & hypotension

28.  Decreased uteroplacental perfusion and fetal hypoxia
 Appropriate maternal hemodynamic monitoring & use of
fluid boluses or vasopressors may be required
 To avoid high concentrations of volatile anesthetic
agents, short acting but profound uterine relaxants like
IV nitroglycerin
 Intravenous infusion of MgSO4 towards the end of
surgery, subcutaneously turbutaline and indomethacin
postoperatively

29.  Adequate post operative maternal analgesia
results in lower plasma oxytocin levels and also
decreases uterine tone
 Placement of an epidural catheter preoperatively
and local anesthetic initiated postoperatively is
an important measure to prevent preterm labor

30.  Opioids can be transferred to the fetus by
maternal administration or direct IM or IV
umbilical cord administration using USG
guidance
 Fetal intramuscular administration of fentanyl 10
to 20 μg/kg (invasive procedures)
 Prophylactic IM atropine 20 μg/kg with opioids to
minimize the risk for fetal bradycardia

31.  Fetal movement can be prevented by IM or
umbilical vessel administration of muscle
relaxant using USG-guidance
 Vecuronium with doses of 0.3 mg/kg IM or 0.1 to
0.25 mg/kg IV
 Maternal administration and placental transfer of
IV remifentanil provides adequate fetal
immobility during fetoscopic interventions that
involve only the umbilical cord or placenta

32.  For open fetal procedures, placental transfer of
maternally administered general anesthesia with
volatile anesthetics provides fetal anesthesia
 Echocardiography, pulse oximetry, and
ultrasound imaging of umbilical artery flow are
the primary methods for fetal assessment

33.  EXIT procedure: insertion of a fetal scalp
electrode has been used successfully for FHR
monitoring
 Echocardiography, pulse oximetry, and USG
imaging of umbilical artery flow are the primary
methods for fetal assessment
 Intraoperative USG allows imaging of FHR,
cardiac contractility, and cardiac filling, as well as
Doppler assessment of umbilical cord flow

34.  In utero, the fetus is unable to thermoregulate &
depends on maternal body temperature
 Induction of GA, surgical exposure, and
hysterotomy can reduce fetal temperature
 Monitoring of temperature and maintenance of
maternal euthermia with use of forced air
warming likely improves fetal well-being during
minimally invasive procedures

35.  During open fetal surgery, use of warmed fluid
for intrauterine irrigation & maternal core and
amniotic fluid temperature monitoring

36.  Intrauterine transfusion for Anemia
 18-20 weeks gestational age
 Umbilical vein access
 Intraperitoneal transfusion
 LA, with minimal maternal
sedation and analgesia
 FIGS-IT

37.  Aortic balloon valvuloplasty for treatment
of critical AS & evolving HLHS: most common
 Atrial septostomy for highly
restrictive or intact atrial septum
 Maternal local anesthesia infiltration
or neuraxial block
 FIGS-IT

38.  Posterior urethral valves, urethral obstruction
 Percutaneous USG-guided vesicoamniotic
shunt placement( FIGS-IT)
 Fetal bladder decompression in an effort to
improve renal development and reduce the
pulmonary hypoplasia associated with
oligohydramnios

39.  Monozygotic twins
 Nonviable twin perfused with retrograde blood from
other twin with no share in placenta
 Inadequate perfusion of recipient twin: acardia &
acephalus
 High-output congestive heart failure and preterm birth
secondary to the increased uterine volume from
polyhydramnios and increased size of the hydropic
nonviable twin

40.  Treatment : Cessation of flow in the recipient
twin’s umbilical artery & death of nonviable fetus
 Endoscopic laser photocoagulation of vascular
anastomoses/RFA at the base of umbilical cord
within abdomen of the acardiac twin
 Maternal infiltration of LA at the fetoscope
insertion site, & neuraxial anesthesia

41.  Monochorionic twins
 Share the same placenta & have intertwin vascular
connections creating shared blood flow between the
two fetuses
 Chorionic vascular anastomoses can result in
unequal placental blood flow between the two
monochorionic twins, creating a significant degree of
intertwin discordance that can lead to twin-to-twin
transfusion syndrome (TTTS)

42.  Recipient twin: increased blood flow leads to
polycythemia, polyuria, polyhydramnios & can
cause hypertrophic cardiomyopathy, hydrops
fetalis, & fetal death
 Donor or “pump” twin: typically
hypovolemic,IUGR, & oligohydramnios;
primarily at risk for renal failure, cardiac failure,
and hydrops fetalis secondary to the high
cardiac output state

43. Treatment:
 Selective fetoscopic laser photocoagulation
(SFLP) of the vascular anastomoses between
the two twins
 Serial Amnioreductions
 Maternal neuraxial blockade or local anesthesia
infiltration from maternal skin to myometrium

44.  During early gestation, abdominal contents
herniate into the thoracic cavity and compress the
fetal lungs
 Pulmonary hypoplasia, respiratory insufficiency,
and PAH
 Fetal intervention for CDH aims to improve fetal
lung development and prevent the morbidity of
pulmonary hypoplasia

45.  Fetal lungs secrete over 100 mL/kg/day of fluid
that exits the trachea and mouth into the
amniotic cavity
 Minimally invasive approach includes reversible
fetal tracheal occlusion which restricts the
normal outflow of the fetal lung fluid and
provides an increase in pulmonary hydrostatic
pressure

46.  This increased pressure pushes the viscera out
of the thorax, promotes expansion of the
hypoplastic lung, & thereby improves lung
growth & development
 Percutaneous endoscopic endotracheal
intubation used to place a small detachable
occlusive balloon in the fetal trachea ; Later it is
deflated and removed before term with a second
fetal endoscopic surgical techniques procedure

47.  Preoperative:
 Complete maternal history, examination & Complete fetal
workup to exclude other anomalies
 Lumbar epidural placement with test dose
 Prophylactic premedications: Nonparticulate antacid
(aspiration),rectal indomethacin (tocolysis)
 Blood products typed and crossmatched for potential
maternal & fetal transfusion;
 Obtain estimate of fetal weight to aid in weight-based
fetal dosing

48. TAKE HOME POINTS

49.  Intraoperative:

51.  Postoperative

52. Thank You