INTERVENTIONAL INTERVENTIONAL ULTRASOUNDULTRASOUND

AN AN

OVERVIEWOVERVIEW

DR.R.UDAYAKUMARDR.R.UDAYAKUMAR

CHENNAI, INDIA.

ULTRASOUND GUIDANCEULTRASOUND GUIDANCE

TRICKS AND TIPSTRICKS AND TIPS

GENESIS SCANS ULTRASOUND TRAINING CENTER

PROCEDURES

• AMNIOCENTESIS-diagnostic / therapeutic

• C V S

• CORDOCENTESIS-sampling / transfusion

• BIOPSY- fetal skin / liver

• SHUNTS-vesicoamniotic / thoracoamniotic

• FETOSCOPY -usg guided

• FETAL GENE Rx- stem cell transplants

PRINCIPLES

• AMNIOCENTESIS

• C V S

• CORDOCENTESIS

• BASICS ARE THE SAME

PLANE OF BEAM - tips

• Varies with different transducers

• Unusual to be in precise middle of Tz.

• Identify the ‘sweet spot’

• 22g and above needles bend ( get rigid 22)

• Use PHANTOM to practise ( Jar of GEL)

• Optimize machine setting

FREE HAND TECHNIQUE

• PERPENDICULAR OFFSET ( 90º ) needle too far away

• PARALLEL or SIDE ON only needle tip is visualized

• END ON APPROACH ( 45º) variable angle / probe can be rocked

targetSEEN - targetNEEDLED

• SONOENHANCED needles ( ??)

• STERILE ZONE -double glove, shroud

• LOCAL ANAESTHETIC (amnio??) initial marker for needle path

• ANTIBIOTICS ( for high risk cases)

• COLOUR DOPPLER

• DETAILED INFORMED CONSENT

TECHNIQUE

• Proper planning

• Good equipment

• Operator skill

• CONTINUOUS NEEDLE VISUALISATION IS A MUST.

TECHNIQUE

• Single main operator ( + assistant)

• Two operators ( sonologist + operator)

• ONE CEREBELLUM IS BETTER THAN TWO FOR CO-ORDINATION.

ARTEFACTS

• NEAR FIELD BACKSCATTER REVERBERATION( ? Anterior Placenta)

• RING DOWN (Comet tail)- Needle Tip

• REFRACTION & MIRROR IMAGE (Wrong location)

• BEAM THICKNESS- Needle position.

Coelocentesis• Between 6 -12 weeks

• Advantage of early Prenatal diagnosis(< 10w)

• 95% success rate bet 7 - 10weeks

• Low rate of contamination by maternal cells.

Coelocentesis

• Early amnio and CVS not performed before 10weeks

• Less traumatic to embryo & placenta

• Fetal loss = 0r < that in early amnio.

Coelocentesis• Biochem. different from early Amniotic

fluid and maternal serum.

• Study materno-fetal exchange when FBS cannot be obtained.

• Prenatal diagnosis of chromosomal and genetic disorders.

Coelocentesis-Procedure

• EVS + Needle guide + 20g needle

• Through “Anterior ut.wall”

• Needle el to amniotic membrane.

• Needle afaap from YS and Amn.membrane

Coelocentesis-Procedure

• Low pressure aspiration.

• Continuous monitoring of needle.

• Yellow coloured and more viscous than Amniotic fluid (always clear)

Coelocentesis

• 5 to 6 ml volume by 9weeks

• 1 to 2.5ml required for diagnostic purpose.

• 90% of cells are viable (before 7weeks)

• Cells : mostly of haemotopoietic origin.

Coelocentesis (vs)

Placental DNA

• Complete concordance in results for

• (1) Diagnosis of single gene disorders (sickle cell)

• (2) PCR with Y centromeric primers for Sex prediction ( 100%)

Coelocentesis

• Easy to learn, new invasive approach to prenatal diagnosis.

• Using FISH probes it appears Karyotyping is possible at 6weeks gestation.

• Further work is necessary to improve culture success later in gestation

Umbilical cord catheterization

• Fetal blood exchange transfusions

• < 5mins procedure

• Catheter in vein for 30 - 210 mins

Umbilical cord catheterization

• No haematomas within Wharton’s jelly

• No chorioamnionitis.

• Nutrient supplementation / Gene therapy/ treatment of fetal pain and infection.

Tracheal Ligation in CDH

• Purposeful occlusion of the fetal airway results in lung growth avoiding pulmonary hypoplasia, which is the main complication in fetuses with CDH.

• The hernia is then repaired after birth

Tracheal ligation - exclusion criteria

Unwilling patient Presence of major congenital anomalies Abnormal karyotype Ruptured membranes Chorioamnionitis Diagnosis made after 25 weeks gestation

EXIT- ex utero intrapartum treatment

What is an Amniopatch?

• ONE unit of maternal blood.

• Blood Bank obtains platelets and cryoprecipitate (cryo) in 2 days

• USG guided injection of these into amniotic cavity takes only a few minutes.

Amniopatch

• Platelets activate the clotting mechanism and the cryo acts like a cement to hold the platelets in place.

• It can take 2 weeks for the membrane to reattach.