Interventional Ultrasound - Easy to Learn

1. INTERVENTIONAL
ULTRASOUND
Syed Yousaf Farooq

2. ULTRASOUND GUIDANCE
TRICKS AND TIPS

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
• LOCALANAESTHETIC (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.