INTERVENTIONAL ULTRASOUND

1. INTERVENTIONAL ULTRASOUND AN OVERVIEW DR.R.UDAYAKUMAR CHENNAI, INDIA.

2. ULTRASOUND GUIDANCE TRICKS AND TIPS GENESIS SCANS ULTRASOUND TRAINING CENTER

3. 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

4. PRINCIPLES AMNIOCENTESIS C V S CORDOCENTESIS BASICS ARE THE SAME

5. 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

7. 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

9. 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

11. TECHNIQUE Proper planning Good equipment Operator skill CONTINUOUS NEEDLE VISUALISATION IS A MUST.

12. TECHNIQUE Single main operator ( + assistant) Two operators ( sonologist + operator) ONE CEREBELLUM IS BETTER THAN TWO FOR CO-ORDINATION.

13. ARTEFACTS NEAR FIELD BACKSCATTER REVERBERATION( ? Anterior Placenta) RING DOWN (Comet tail)- Needle Tip REFRACTION & MIRROR IMAGE (Wrong location) BEAM THICKNESS- Needle position.

15. Coelocentesis Between 6 -12 weeks Advantage of early Prenatal diagnosis(< 10w) 95% success rate bet 7 - 10weeks Low rate of contamination by maternal cells.

17. Coelocentesis Early amnio and CVS not performed before 10weeks Less traumatic to embryo & placenta Fetal loss = 0r < that in early amnio.

19. 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.

21. Coelocentesis-Procedure EVS + Needle guide + 20g needle Through “Anterior ut.wall” Needle ? ?el to amniotic membrane. Needle afaap from YS and Amn.membrane

23. Coelocentesis-Procedure Low pressure aspiration. Continuous monitoring of needle. Yellow coloured and more viscous than Amniotic fluid (always clear)

25. 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.

27. 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%)

28. 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

29. Umbilical cord catheterization Fetal blood exchange transfusions < 5mins procedure Catheter in vein for 30 - 210 mins

32. Umbilical cord catheterization No haematomas within Wharton’s jelly No chorioamnionitis. Nutrient supplementation / Gene therapy/ treatment of fetal pain and infection.

33. 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

35. Tracheal ligation - exclusion criteria Unwilling patient Presence of major congenital anomalies Abnormal karyotype Ruptured membranes Chorioamnionitis Diagnosis made after 25 weeks gestation

36. EXIT- ex utero intrapartum treatment

37. 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.

38. 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.