1. Patent Ductus Arteriosus Occlusion Device
Christina Mathieson
Trung Nguyen
Advisor: Dr. Tom Doyle
BME 273 – Senior Design Project

2. Patent Ductus Arteriosus: General Information
Connection of aorta and pulmonary artery
Functionally beneficial prior to birth
Maintained by low oxygen and high prostaglandins
Usually closes within hours of birth
Abnormal if patent after 3 months
1 in 2500
Female:male 2:1

3. Patent Ductus Arteriosus: Causes
All factors unknown
Prematurity of infant
Rubella infection
Random

4. Patent Ductus Arteriosus: Effects
Increased volume load on left atrium and ventricle
Distention and dilation
Delay in postnatal pulmonary vascular changes
Growth retardation, breathlessness, poor feeding
Congestive heart failure
Bacterial endocarditis, aneurysm of ductus

5. Patent Ductus Arteriosus: Shapes
Type A: Cone
Type B: Window
Type C: Tube
Type D: Aneurismal
Type D: Irregular Cone

6. Patent Ductus Arteriosus: Sizes
Narrowest segment average: 3.2±1.0 mm
Range: 2 mm – 8 mm
Length is highly variable (mm – cm)
Size variable regardless of shape

7. Current Treatments: Surgery
Left posterolateral thoracotomy
Ligation or dissection
Chest tube 24hrs
Hospital 6-7 days
6-8 month recovery

8. Current Treatments: Coils
Most common method
Use multiple coils
Materials:
Surgical grade stainless steel
Dacron fibers
Problem:
Cannot occlude smaller PDAs
Easily dislodge when too many coils

9. Current Treatments: Rashkind
Double Umbrella
Polyurethane fabric on stainless steel frame
Wire frame limits sizes
Must pre-order based on approx. size of PDA

10. Our Goals PDA occlusion device Delivered via 6 – 7F catheter
Effective for all ages
Conforms to various shapes of PDA
Able to retract and reposition
Biocompatible material (foam)
Low cost

11. Project Timeline Dec Jan Feb Mar Apr Research *** Advisor Meeting *
Material Decision **
Design
Prototype
Testing

12. Work Completed Research Modified mushroom shape
PDA background: current treatments, material ideas, catheter sizes
Device shapes: Rashkind, coils, etc.
Modified mushroom shape
Material specifications
Delivery device prototype plan

13. Modified Mushroom Shape
Flat top in aorta
Modified top to prevent shunts (thicker in middle)
Conical / Tubular base in PDA
Top prevents dislodging
Base provides surface for coagulation

14. Material Specification
Biocompatible to circulatory system
Properties of blood (immune system, no deterioration, etc.)
Able to withstand pressure differences
Malleable
Easy to mold
Expandable, able to fit in 6F catheter
Inexpensive

15. Delivery System Plan 6F catheter
Similar to Rashkind implantation procedure
Enter PDA via Pulmonary Artery
Enlarged prototype:
Foam piece approx 3 cm long, 1 cm wide
Catheter represented by straws
PDA represented by glass tubing

16. Future Work Test prototype Visit catheter lab Meet with Dr. Doyle
Prepare for poster presentation