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

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 10-18 hours of birth Abnormal if patent after 3 months 1 in 2500 Female:male 2:1

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

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

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

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

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

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

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

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

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

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

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

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

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

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