1. Trans catheter closure of Preterm Ductus Arteriosus
Dr.Sajit Augustine
TnECHO Fellow, Children’s Hospital of Eastern Ontario, Ottawa, ON, Canada.

2. Patent ductus arteriosus
Persistent patent ductus arteriosus is associated with earlier gestational age and lower birth weight.
Rates of patent ductus arteriosus in preterm infants range from 29 to 80%, depending on the population studied.
PS Shah et al: Outcomes of preterm infants <29 weeks gestation over 10-year period in Canada: a cause for concern?

3. PDA Management: A continuing conundrum

5. Surgical Ligation Hemodynamically significant PDA + medical Rx failed
Unstable babies
Contraindications to medical Rx
NEC
IVH
ARF

6. Surgical Ligation-Complications
Little :Texas
212 babies Median GA 26wks,
72 babies ligated
Afif
30 babies Mean GA 25.3wks
Solid line: Low LVO
Dotted line: High LVO

7. Surgical Ligation-Long term outcomes
g TIPP study ( )
Journal of Peds 2007 Post hoc analysis
426 with symptomatic PDA
316 Medical therapy
110 PDA ligation

8. Surgical Ligation-Long term outcomes
Pediatrics 2009
NICHD Neonatal Research Network: , 23-28wks, <1000g
N=2838
Supportive: 403
Indo: 1525
Indo+Surgery: 775
Primary surgery: 135
Primary surgery: Increased odds for NDI/BPD Secondary surgery: Increased odds for NDI/BPD

9. Surgical Ligation-Long term outcomes
JAMA Peds
Retrospective cohort
N=754, <28wks HSPDA
184 ligations
Adjusted for pre ligation morbidities: No difference in the odds of death or NDI, CLD, ROP

10. Surgical ligation- Variability of Practice
Diagnosis rate for each state determined by the number of PDA diagnoses per preterm infant in that state.
Ligation rate for each state determined by the number of PDA ligations per preterm infant with a PDA in that state.
States of California, Colarado, New Mexico, Nevada, Oklahoma: Highest rate of diagnosis
High Ligation rates: Hawaii, Minnesota, Oregon, Oklahoma
Weinberg et al, 2016

11. Surgical Ligation-Summary
Surgical ligation is associated with significant procedural morbidity and may or may not be associated with adverse long term outcomes.
Is there an alternative?

12. Transcatheter closure of PDA

13. Percutaneous Ligation-Proof of Concept
Portsmann’s Ivalon plug
Rashkind PDA Occluder system
Portsmann et al. 1966, 1st transcatheter closure of a PDA without thoracotomy in a 17-year-old boy.
The device used was an Ivalon plug, introduced through an 18 F femoral arterial sheath and travelling on a percutaneously laid transductal arteriovenous guide wire.
Rashkind: First in Infants (<3500g). Two polyurethane discs mounted on opposing three- or four-arm spines were assembled, resembling two umbrellas. The 146 patients treated in 1987.
Success rate: 66%
Device embolization:15%
Disadvantage: Large & bulky size of the arterial delivery sheath.
Portsmann Ivalon plug 13F-28F femoral arterial access
Rashkind double disc 8F-11F femoral venous access

14. Percutaneous Ligation-Proof of Concept
Sideris-1993
Clamshell septal umbrella
Sideris: Buttoned device. 7F
Lock Clamshell device

15. Premature enthusiasm? High incidence of residual leak
Problems
Desirable
High incidence of residual leak
Risk of endarteritis
Device instability
Major complications
Delivery via a small-sized catheter.
Repositioning of the device multiple times
Easy retrieval of the device.
Ability to allow for complete closure without causing any aortic/pulmonary artery obstruction or damage.
Gradually abandoned because of a high incidence of residual leak and subsequent persistent risk of endarteritis, device instability or other major complications.
Thus, despite initial widespread enthusiasm, reproducible and safe percutaneous PDA closure proved to be more difficult than initially estimated.

16. Embolization coils Immediate success rate 75-95%
Rate of closure inversely related to the size of the ductus.
Operator dependent
Inexpensive & feasible via small catheter.
Unacceptably high rate of coil embolization

17. Amplatzer Duct Occluder
Self expandable repositionable mushroom-shaped device
inch-thick nitinol wire mesh with Dacron patches within.
Masura et al.(1998) reported the initial successful experience with the ADO in 24 patients using an antegrade approach and a transvenous 6F delivery sheath.
Masura: Median age of 3.8 years (range 0.4 to 48) and a median weight of 15.5 kg (range 6 to 70). The mean PDA diameter at its narrowest segment was 3.7 +/- 1.5 mm.

18. The Present: daily practice in the Cath lab
Treatment of choice for most PDAs in term infants, children and adults.
Timing: Delayed if feasible, until later in the 1st year of life (peripheral vascular injury risk)
Pre catheterization care
Rule out infection
ECHO: Associated lesions, LV volume diameters, Function, PDA size, Pulm art pressure, hemodynamic significance of PDA.

19. Angiographic classification
Krichenko et al described ductal anatomy in lateral projection
Type A: Conical ductus
Type B: Large and very short ductus
Type C: Tubular duct
Type D: Multiple constrictions on the ductus.
Type E: Elongated ductus.
Angiography with 4F/5F pigtail catheter in proximal descending Ao
Type A: Well defined Ao ampulla & constriction at pulmonary end.
Type B: Mimicks AoPulmonary window.
Type C: Varying length, no constriction at pulmonary end.

20. Coil occlusion Safe & effective for small PDA (<1.5-2mm)
3:1 principle
Krichenko type A1 or E
Technique: Most common: Arterial retrograde.
Indication: 3:1 principle, the coil is the chosen strategy if the total ductal length is more than three times the narrowest diameter of the PDA.
Or minimal ductal diameter < 1.5—2 mm as an indication for coil implantation, as device implantation in such small PDAs can be challenging.
Shorter ducts/>3mm ducts: Residual shunts or coil embolization.
Steps
Femoral access
4F/5F pigtail cath in Prox Desc Ao- Angiography
PDA is crossed by a inch wire and a delivery catheter is then advanced over the wire into the main pulmonary artery (MPA)
Rule of thumb, a coil is chosen with a loop diameter that is a minimum of two times the diameter of the narrowest segment of the ductus and the length of coil is suitable to allow for four or five coil loops.
Non-ferromagnetic coils (e.g. MREYE) are more commonly used than the prior stainless steel variety.

21. Device Occlusion ADO most commonly used device worldwide.
Approved for >6months & >6kg
Antegrade approach
PDA >2mm+ sufficient aortic ampulla
0.035-inch wire is passed anterograde from the MPA, across the ductus to the abdominal aorta.
Delivery sheath
ADO device is positioned
Retention skirt deployed first in Desc Ao

22. Transcatheter-Results and complications
Incomplete closure
High-velocity residual shunting: Endocarditis, hemolysis.
Embolization: Pulmonary arteries, systemic artery.
LPA stenosis or coarctation of aorta: LBW, Large PDA with large device.
Pass et al: ADO: Successful implantation 99%, Acute angiographic occlusion: 76%, Post cath Day 1: 89%, 1yr: 99.7%
Incomplete Closure: Needs Repeated procedures.
Embolization: 1% occurrence rate
Device closure: Acceptable to leave Cath lab with residual shunting.
PDA coil embolization: Leave cath lab only after documentation of angiographical closure.

23. Post catheterization care
Prophylactic antibiotics
Post op CXR and ECHO
Follow up
No residual shunt, normal LV and pulm artery pressure: None after 6 months.
LV dysfunction & PAH: q1-3yrs
CXR:/ECHO: Confirm position of device/coil, absent of residual shunt.

24. How rigorous is the evidence regarding technical success and safety?

25. Search Date Dec 2015
Outcomes:
Technical success
Safey
38 studies included
Significant heterogeneity
Publication Bias

26. Overall adverse Events

27. Clinically significant adverse events

28. Transcatheter closure in Preterm & LBW
Challenges: Sheath size, stiffness of delivery system, protrusion risk of device in LPA or Ao, technical difficulties for device retrieval.
Off-label ADO.

29. French Muticentre study
58 infants <6kg
Success rate 89.7%
Procedure related mortality 1.7%
Major complication rate: 6.9%
Minor complication rate 31%
Conclusion: Recommend surgery over percutaneous closure in LBW

30. 62 patients
Success rate: 94%
No deaths

31. 8 infants <2kg ( g)
Coil
Case selection: Patient’s weight, PDA size, size of ampulla,
and the anticipated coil mass required for complete closure (determined through echocardiography).
Success rate: 100%
No major procedure or access related complications

33. The future: new devices and perspectives
Growing experience
Miniaturization of materials
Newer devices: Amplatzer Duct Occluder II

34. Perspectives
Trancatheter closure of PDA remains a challenge in preterm and LBW infants
New generation of devices
Shorter
Large choice of available diameters
Suitable for 3F or 4F sheath.
Which preterm and how?
Fluoroscopic radiation dose or no fluoroscopy (ECHO guided?)

35. Thank you
Questions?