5. PLANE OF BEAM -TIPS
⢠Varies with different transducers
⢠Unusual to be in precise middle of Tz.
⢠Identify the âsweet spotâ
⢠22g and above needles bend ( get rigid 22)
⢠Use PHANTOM to practise ( Jar of GEL)
⢠Optimize machine setting
6.
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
8.
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
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.
14.
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.
16.
17. COELOCENTESIS
⢠Early amnio and CVS not performed before
10weeks
⢠Less traumatic to embryo & placenta
⢠Fetal loss = 0r < that in early amnio.
18.
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.
20.
21. COELOCENTESIS-PROCEDURE
⢠EVS + Needle guide + 20g needle
⢠Through âAnterior ut.wallâ
⢠Needle ďŻ ďŻel to amniotic membrane.
⢠Needle afaap from YS and Amn.membrane
22.
23. COELOCENTESIS-PROCEDURE
⢠Low pressure aspiration.
⢠Continuous monitoring of needle.
⢠Yellow coloured and more viscous than
Amniotic fluid (always clear)
24.
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.
26.
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
32. UMBILICAL CORD CATHETERIZATION
⢠No haematomas within Whartonâs 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
34.
35. TRACHEAL LIGATION - EXCLUSION
CRITERIA
ďˇ Unwilling patient
ďˇ Presence of major congenital anomalies
ďˇ Abnormal karyotype
ďˇ Ruptured membranes
ďˇ Chorioamnionitis
ďˇ Diagnosis made after 25 weeks gestation
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.