ANAESTHESIA FOR INTRAUTERINE FETAL SURGERY

PRESENTED BY- Dr. Anupam

MODERATOR- Dr. Yashwant

Fetal surgery is ………..Indicated in conditions which interfere

with the normal development of the fetus in-utero but

Which when corrected will allow the development of the fetus normally.

It is contraindicated in conditions that are incompatible with lifemedical condition in the mother

precluding surgery.

3 types of fetal surgery :-EXIT (Ex-Utero Intrapartum

Treatment Procedure)Mid gestation Open Surgery Minimally invasive mid gestation

procedures FETENDO (Fetal Endoscopic

Surgery)FIGS (Fetal Image Guided

Surgery)

EXIT ( Ex-utero intrapartum treatment ) :- Also know as OOPS.It is the intervention that occurs at

the time of deliveryIt is primarily used in cases where

baby’s airway requires surgical intervention

It starts as a routine LSCS but under GA

Head of the baby is delivered, but the placenta is in situ

The baby gets oxygen from placenta via umbilical cord

Bronchoscopy of the fetal airwayEndotracheal intubation

attemptedIf unsuccessful then

tracheostomy is doneO2 delivery to lungs confirmedCord is cut & Baby is delivered

Indications:- Giant cervical neck mass.CHAOS (Congenital High Airway

Obstruction Syndrome- tracheal atresia)

Removal of balloon after CDHCCAM (Congenital Cystic

Adenomatoid Malformation)

Mid gestational open fetal surgery:-Surgery performed between 18-26

weeks through hysterotomy.Fetus exteriorized for surgery then

placed back in uterus to mature. Indications :- CCAM (Congenital Cystic Adenomatoid

Malformation of Lung)- LobectomySCT (Sacro-coccygeal Teratoma)-

ResectionMMC (Meningo Myelocoele)- Repair

FIGS (Fetal Image Guided Surgery) :-

Ultrasound image guided procedure

Least invasiveLeast risk of

amniotic fluid leak

Least risk of PT labour

Indications :-Diagnostic :-

Chorion Villus Sampling

AmniocentesisCordocentesisFetal skin Biopsy

Therapeutic :-

RFA (Radio Frequency Ablation) of anomalous Twins

Cord cauterization in Twins

Vesical / Pleural Shunts

Balloon Dilatation of Aortic Stenosis

FETENDO (Fetal Endoscopic Surgery) :-Fetoscopic access to

the FetusThe fetal

visualisation is a combination of endoscopic and sonographic on two different screens

Less invasive Less risk of amniotic

fluid leakLess risk of PT

labour

Indications :-CDH (Congenital Diaphragmatic

Hernia)-Balloon Occlusion of trachea

TTTS (Twin to Twin Transfusion Syndrome)- Laser coagulation of vessels

Cord ligation in cases of acardiac Twins

Amniotic bands division

ANAESTHESIA FOR FETAL SURGERY

ANAESTHETIC CHALLENGESThose related to any anaesthetic

technique in a pregnant femaleTechniques used to prevent

preterm labourMaintenance of maternal

hemostasis in face of tocolytic techniques

Maintenance of fetal hemostasisProvision of fetal analgesia.

Anaesthetic considerations :- Maternal FetalUteroplacentalPreoperative assessmentType of anaesthesiaIntraoperative managementPost operative carecomplications

Maternal anesthetic considerations:-

Risk of aspiration pneumonitis Risk of pulmonary edema Risk of hypoxia Risk of supine hypotension

syndrome Risk of massive hemorrhage Myocardial depression,

hypotension

Fetal anaesthetic considerations:-

Fetal anaesthetic considerations:Fetal Cardiac Output is sensitive to heart

rate changesFetus has high vagal tone & low

barorecepter sensitivity ,hence responds to stress with precipitous bradycardia.

Fetal circulating volume is low( 110ml/kg), hence little intra-operative bleeding can cause hypovolemia.

Inhalational agents depressess fetal circulation as well-direct myocardial depression, vasodilatation, changes in arterio-venous shunting.

Fetus tends to lose heat much easily from the exposed skin resulting in hypothermia

Immature coagulation system predispose the fetus to bleeding and difficulty in achieving hemostasis.

Maternal anesthesia reduces placental blood flow, this reduces the amount of O2 delivered to the fetus( hypoxia)

Normal Fetal oxygen saturation is 60-70% and the aim is to maintain it above 40%

Intra-operative fetal distress is manifested by bradycardia, decreased fetal oxygen saturation and reduced stroke output.

Uteroplacental considerations:-

Maternal hyperventilation is avoided as maternal hypocapnia causes fetal placental vasoconstriction and fetal hypoxia.

Maternal BP & myometrial tone correlates with uterine artery blood flow.

Maintenance of patent UA & maintenence of maternal BP with in 10% of baseline is critical.

Pre-operative assessment:-Assessment of the mother for fitness

for anaesthesiaAssessment of the fetus

◦Detailed USG to r/o other malformations◦3D and 4D examination-Detailed

examination of affected organ system◦Detailed Fetal Echocardiography,

Amniocentesis, Localization of placenta◦Fetal MRI Maternal blood cross matched- arrange

blood for mother and fetus.

Anaesthesia for open fetal surgery:- Pre-operative preparation-1. OT warmed2. Blood arranged3. Monitors and syringes4. Prophylaxis for Aspiration 5. Lumber epidural inserted &

tested6. Indomethacin suppository

administered7. Positioning done

The fetus is monitored with Fetal

Echocardiography

Pulse OximetryPO2 from Cord

BloodFetal Hb from

Cord Blood

TYPES OF MATERNAL ANAESTHESIA :-

Regional Anaesthesia-Lumbar Epidural

Deep GA-(Sodium Pentothal + Scoline) + (Isoflurane + Fentanyl+O2 + Vecuronium)

GA with N2O- (Sodium Pentothal + Scoline) + (Isoflurane + N2O + Vecuronium)

Intraoperative management:-

Rapid sequence induction with thiopentone & Sch.

Maintenence – Nitrous plus oxygen plus 0.5 MAC (isoflurane, desflurane)

Invasive arterial line, secure 2nd venous catheter, NG tube & Foley's catheter insertion.

Fetal status monitored by sterile intraop echocardiography.

Restrict fluids in mother ( post op PE )Before hysterotomy, nitrous turned off

& deepen the patient by increasing inhalational agents to 2 MAC

Maintain maternal BP – ephedrine/PEFetus is given I/M opioids b4 incision.Fetal monitoring with Miniature pulse

oximeter & echocardiography done.Blood gas samples help guide therapy

during period of fetal distress.Following closure of uterus, anaesthesia

converted to regional based technique.( LA,opioids through epidural catheter)

Tocolysis instituted via MgSo4 loading dose followed by infusion.

Patient extubated and shifted to recovery.

Post-op management:-Tocolysis for at least 18-24 hours.Adequate maternal pain relief

with epidural.

Anaesthesia for EXIT :-No tocolysisOne additional OT for possible fetal sugeryDesflurane inhalational agent of choice.During hysterotomy, only partial exposure

of fetus done.DL / intubation done by surgeon or

anaesthesiologist.If baby cant be intubated , tracheostomy

done.After assuring adequate fetal oxygenation

cord clamped & fetus delivered.

The timing of cord clamping with respect to administration of oxytocin, methergin and carboprost as well as decreasing volatile agents must be coordinated between anaesthesiologist and surgeon .

Blood loss is monitored and cross matched blood is administered if needed.

If surgery is not required immediately, a neonatology team resuscitates and transports the neonate to NICU.

Fetoscopic surgery:-Epidural anaesthesia:- less effect on fetal

hemodynamics & UP circulation & post op uterine activity but lack of uterine relaxation, lack of fetal anesthesia hence, difficulty manipulating the uterus & cord while baby is still moving.

Balanced inhalation-opioid anaesthesia:- it eliminates anxiety, nausea, emesis and allows immobile anaestheized fetus, less CV effects than deep inhalational, but provides no uterine relaxation.

Deep inhalational anaesthesia:- provides profound uterine relaxation but affect fetal hemodynamics & UPBF

Maternal complications: -Tocolytic therapy can cause pulmonary

edemaSubsequent delivery by LSCSMassive hemorrhageAmniotic fluid leakWound infectionIntra uterine infection“Maternal Mirror Syndrome” in cases of

fetal Hydrops ( mother mirrors the symptoms that fetus is experiencing)

Chorio-amniotic membrane separation

Fetal complications:- PrematurityIntra Uterine InfectionFetal vascular embolic events

◦Intestinal atresia◦Renal agenesis

Premature closure of Ductus ArteriosusCNS injuries due to maternal hypoxia or

fetal circulatory disturbanceBleeding