Patent Ductus and Vascular Occlusion Devices Michelle Carlsen Elaine Isom Brad Klosterman Ornob Roy Advisor: Dr. Thomas Doyle

Project Definition Objective: Design, build, and market an occlusion device which can be used to close the Patent Ductus and cylindrical vasculature Presentation topics: –Background –solution –accomplishments –current status –future plans

Background:Patent Ductus Condition affecting Infants/Children ~ 10-12% of congenital defects 40 cases/yr at Vanderbilt > 20,000 nationwide Connection btw pulmonary artery and aorta

Background: General Vasculature Less common than PDA Cylindrical shape Reroute blood flow Isolate defective vasculature Impede significant flow

PDA/ Vascular Conditions Diagnosis: –Heart murmur –Extreme weight loss –Stunted growth –Irregular blood flow * * General vasculature Consequences: –Irreversible pulmonary- vascular disease –Congestive heart failure –Hemorrhaging (e.g. diabetics, post-surgical patients) *

Requirements Biocompatible Quick endothelialization (1- 2months) Delivered through a catheter < 2mm diameter Simple, Retrievable Inexpensive Various size (2 to 10mm) Form-fitting Maximum effectiveness – Internal device – Complete closure – Standard catheter size – Minimum training – Cost effective - comparatively – Universal Device – Immovable and closure – No leakage

Current Solutions Endomethiasin –initial form of treatment –steroid medicine (vasoconstrictor) –restricted to premature infants Suturing –effective –invasive, long recovery Coils –inexpensive –not form fitting Titanium devices –form fitting –very expensive Ultrasonic Devices –non-invasive –high-intensity –not human tested

Accomplishments Identification of associated diseases Analysis of previous device designs Studies in biocompatible materials (Prof. Kinser, Material Sciences) Fluoroscopy viewing SDRC I-DEAS CAD/CAM modeling Began mock circulation system

I-DEAS Modeling Goal –allow for quick and accurate prototyping –marketing and visualization

Current Status 3D modeling using SDRC I-DEAS Material search 4 design concepts Large scale simulation: drawings, materials, construction

Design 1 Advantages: adjust on contact expandable polymer form-fitting (PDA & general) Disadvantages: FDA expensive (polymer & wire retrievable??

Design 2 Advantages: form-fitting (PDA & general) collapsible (>500%) endothelialize quickly inexpensive Disadvantages: complex possible limited retrieval

Design 3 Advantages –very rigid –easily retrievable –adjustable Disadvantages –difficult to maneuver –expensive

Design 4 Advantages: form-fitting (PDA & general) retrievable simple inexpensive Disadvantages: expansion limitations?? Two materials

Material Search Zotefoams –plastazote foam (polyethylene) Medicell –medical sponges Titanium/wire material Thrombosing fibers Polyurethane foam (earplugs) Polyurethane that is modified with lower alkyl Sulfonate and L(L-glutamic acid co L-leucine) –biocompatible, used in surgical implantations and blood contacting procedures

Suitable Materials Hydromer –Medicell Hydrophilic Open Cell Medical Foam –consists of polyurethane and polyvinylpyrrolidone polymers Foamex –Functional Flexibility Titanium Feet

Simulation Echigo, S et al. “ Development of New Transvenous Patent Ductus Arteriosis Occlusion Technique Using a Shape Memory Polymer.” ASAIO Transactions: 1990 pg M197.

Simulation Protocol Large scale Fluid: –water glucose mixture –pig’s blood Pulsatile Pump Latex Tubing (18 flexitube) Plastic PDA (conical 2mm opening)

Division of Labor Elaine/Michelle: –PDA design –material search –literature analysis/search Ornob/Brad: –Vascular Occluder Design –modeling using I-DEAS –simulation design idea, construction Group: –device design ideas –large scale prototypes –designsafe analysis

Future Plans Decide on final design Acquire materials for design Continue meeting with Dr. Doyle Designsafe analysis Large scale replication Patent