2. History of fetal surgery
1965-first intrauterine transfusion…. A.W.Liley
1974-fetoscopy …. Hobbin
1981-fetoscopic transfusion…… Rodeck
1982-first open fetal surgery for obstructive uropathy
by Dr. Michael Harrison (father of open fetal surgery),
University of California, San Francisco
3. What is fetal surgery
It is application of established surgical techniques to
the unborn baby
-During gestation
- At the time of delivery
4. Fetal surgery -prerequisites
Lesion
diagnosed accurately
severity is assessed correctly
defined natural history
Associated anomalies are excluded
Maternal risk is acceptably low
Neonatal outcome would be better than with surgery
performed after delivery
5. fetal surgery
contraindicated
Chromosomal and genetic disorders
Other associated life threatening abnormalities
Timing
Usually performed between 24-29 weeks gestation
Requires combined expertise of
Obstetrician
Anaesthesiologist
Neonatologist
Pediatric surgeon
7. Types of fetal surgery
Open surgery
FETENDO-Fetal endoscopic surgery or fetoscopy or
minimally access fetal surgery (MAFS)
FIGS-Fetal image guided surgery
EXIT-Ex-utero intrapartum treatment procedure
8. Open surgery
Most definitive and most invasive
Performed – middle of pregnancy
Mother anaesthetised by GA
Uterus opened similar to LSCS
Intraoperative sonography – locate the placenta
Incision taken close to the area of interest
Fetal part is exteriorized
Surgical repair of fetus done
9. Indication for open fetal surgery
Defect Treatment
CCAM (Congenital cystic adenomatoid
malformation of lung)
Lobectomy
SCT (Sacro-coccygeal teratoma) Resection
MMC (Meningomyelocele) Repair
CDH Temporary tracheal occlusion
Obstructive hydronephrosis Vesicostomy, ureterostomy
10. FETENDO-fetal endoscopic surgery or MAFS
Fetoscopic access to the fetus
During or after the 18th week of pregnancy
Useful for treating placental problems
Technically difficult
Maintains fetal position
Under LA with infiltration of both skin and
peritoneum+/-sedation
Under epidural, spinal or CSE anaesthesia
High risk for urgent C-section: CSE preferred
Sedation required for maternal anxiolysis
11. Fetendo
Advantages
Less invasive
Avoids maternal hysterotomy
Less risk of amniotic fluid leak
Less blood loss
Less preterm labour and uterine rupture
Disadvantages
Uterus irrigated with NS – absorbed to peritoneum
through fallopian tubes – pulmonary oedema as mother
also receives tocolytics. This can be treated with diuretics
12. Defect Treatment
E.g. CDH( Congenital diaphragmatic
hernia)
Balloon occlusion of trachea
TTTS (Twin-twin transfusion
syndrome)
Laser coagulation of vessels
Acardiac twins in TRAP sequence (twin
reverse arterial perfusion)
Cord ligation
ABS-Amniotic band syndrome Division of amniotic bands
BOO-Bladder outlet obstruction Vesicoamniotic shunt
15. FIGS - fetal image guided surgery
Combination of endoscopic and sonographic method
Ultrasound image guided procedure
Done under RA or LA
Advantages
Least invasive
Least risk
of amniotic fluid leak
of preterm labour
16. Both diagnostic and therapeutic uses
Diagnostic Therapeutic
-Chorion villus
sampling
-Amniocentesis
-Cordocentesis
-Fetal skin biopsy
-RFA of
anomalous twins
-Cord cauterization
in twins
-Vesical/pleural
shunts/catheter
-Balloon dilatation
of aortic stenosis
17. Ex-utero intrapartum treatment (EXIT)
procedure
OOPS-operation on placental support
Intervention occurring at the time of delivery
Used in cases where baby’s airway requires surgical
intervention
Provide the baby with patent airway that can provide
oxygen to the lungs after separation of placenta
Starts as a routine LSCS but under GA with maximum
volatile agent(>2 MAC)
Head of the baby is delivered, but placenta is in situ
Baby gets oxygen from placenta via umbilical cord
18. Surgeon removes the
occlusive device
Bronchoscopy of fetal airway
Endotracheal intubation
done
If unsuccessful, then
tracheostomy tube below the
level of airway blockage is
placed
Oxygen delivery to lungs
confirmed
Umbilical cord is clamped
Baby delivered
20. Considerations during EXIT
procedure
Uterus needs to stay relaxed to permit placental
perfusion
Uterus needs to contract at end to limit bleeding
Needs hemostatic hysterotomy
May permit upto 2 hours of ongoing placental
perfusion
21. Challenges before the field of fetal
surgery
Ethical dilemma
Maternal risk
Fetal risk
Maternal anaesthesia
Fetal anaesthesia
Post surgical tocolysis
22. Anaesthesia -basic considerations
Pre operative evaluation and preparation
Relief of anxiety
Avoidance of fetal asphyxia
Adequate analgesia
Uterine relaxation
Prevention of preterm labour
Maternal safety
Avoidance of teratogenic agents
Fetal anaesthesia and monitoring
23. Fetal assessment
Detailed USG to rule out other malformations
Fetal echocardiography
Fetal MRI
3D and 4D examination
Detail examination of affected organ system
Amniocentesis
Localisation of placenta and umbilical cord
Volume of amniotic fluid
24. Pre-operative preparation
Consent for caesarean delivery
Maternal blood cross matched
Availability of O-negative, CMV-negative, irradiated,
cross matched blood against the maternal antibodies
Adequate aspiration prophylaxis
Indomethacin rectal suppository for postoperative
tocolysis
Epidural catheter-postoperative pain control
Operating room temp
25. Avoidance of fetal asphyxia
Avoidance of maternal hypoxia
Avoidance of maternal hypercapnea
Quick treatment of maternal hypotension
Fluid boluses
Vasopressors
Decreasing anaesthetic concentration
26. Adequate analgesia
Local anaesthesia-0.5 ml 1% lidocaine-infiltration of
both skin and peritoneum
Field block
CSE
27. Prevention and treatment of preterm labour
Tocolytic agent
indomethacin (rectal)
magnesium sulfate
terbutaline (subcutaneous)
nitroglycerine
Halogenated agents-halothane, isoflurane,
sevoflurane
Vascular stasis during hysterotomy-special stapling
device
Postoperative pain control-epidural catheter
28. Maternal sedation and local
anaesthesia
Indicated in percutaneous needle aspirations or
catheter insertions
Drug of choice-BZD(diazepam, midazolam),
narcotics(fentanyl, remifentanil) for maternal anxiety
Disadvantages:
increased hypoxia
unprotected airway; aspiration risk
presence of foetal movements
Close monitoring for 3-4 hrs required
29. Regional anaesthesia
Indicated in MAFS(Minimal access fetal surgery)
Lumbar epidural, spinal or CSE anaesthesia
Advantages:
excellent analgesia and good muscle relaxation
avoids GA
keeps mother awake and alert
minimal effects on fetal hemodynamics, uteroplacental
blood flow and uterine activity
Disadvantages:
Hypotension
lack of fetal anaesthesia, difficulty manipulating uterus and
cord while the fetus may be moving
30. General anaesthesia
Aspiration prophylaxis-sodium citrate, ranitidine,
metoclopramide
Prevention of supine hypotensive syndrome-left lateral tilt
Short acting amnestic-thiopentone
Short acting muscle relaxant-succinylcholine for RSI
Maintenance - 100% O2 with low levels of
inhalational(isoflurane) or 50% O2 and 50% N2O with low
inhalational + vecuronium + fentanyl
Maternal and fetal monitoring
31. Uterus opened similar to LSCS
Fetal part is exteriorized
Special stapling device
Surgical repair of fetus done
Warmed Ringer Lactate along with
antibiotics infused to replace amniotic fluid
At the time of closure, i.v. MgSO4 6 gm over
20 minutes
During extubation, coughing or straining
avoided to maintain integrity of uterine
closure
32. General anaesthesia
• Advantages:
• Profound uterine relaxation
• Allowing uterine manipulation with an immobile
anaesthetised fetus
• Disadvantages:
• Fetal cardiac depression
• Decreased uteroplacental blood flow
35. Fetal anaesthetic considerations
Fetal organ systems are immature
Fetal cardiac output is sensitive to HR changes
Fetus has high vagal tone and thus response to stress
with precipitous bradycardia
Fetal circulatory blood volume is low, hence little
intra-operative bleeding can cause hypovolemia, so
trigger for transfusion is low
During prolonged surgery, fetus need to be transfused
O-negative blood
36. Fetal pain
Not possible to assess fetal pain directly
Assessed indirectly by ability of fetus to mount a stress
response to noxious stimulus-increased fetal cortisol,
beta-endorphins and central sparing hemodynamic
changes
Fetal administration of narcotic inhibits cortisol and
beta-endorphin release but does not inhibit central
sparing hemodynamic changes
Fetal stress to pain starts in 8 weeks gestation age and
may cause preterm labour
37. Advantages of fetal surgery
In utero environment supports rapid post-operative
healing
Rapid healing, fostered by fetal growth factor
Infections are combated by passage of maternal
immune factors
Umbilical circulation meets nutritional and
respiratory needs without outside assistance
Medical agents given directly to fetus have greater
efficacy at reduced doses
38. Postsurgical tocolysis
High risk of preterm labour
Pre-operative: rectal indomethacin
MgSO4 is tocolytic of choice and maintained for 2-3
days-3 gm/hr infusion
Adequate maternal analgesia as maternal pain can
cause preterm labour and fetal distress
Epidural analgesia (PCEA) for 24-48 hrs is
recommended to prevent uterine contractility
39. New researches
Remifentanil produces improved fetal immobilization with good
maternal sedation and only minimal effects on maternal
respiration (Anesth Analg, 2005)
Continuous fentanyl infusion with midazolam provides
acceptable maternal analgesia and sedation during
fetoscopy(Masui, 2008)
In fetoscopic interventions under GA, cardiopulmonary
functions remain stable. However, a moderate increase in
extravascular lung water(EVLW) and pulmonary vascular
permeability indicates an increased risk for maternal pulmonary
oedema(Br J Anaesth, 2013)
Future possibilities
Stem cells or DNA to treat sickle cell anaemia or other genetic
conditions
More potent tocolytics to control preterm labour
Improved techniques of fetoscopic visualisation