Patent Ductus and Vascular Occlusion Devices Michelle Carlsen

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 pulmonaryvascular disease – Congestive heart failure – Hemorrhaging (e. g. diabetics, post-surgical patients)*

Requirements • Biocompatible • Quick endothelialization (12 months) • Delivered through a catheter < 2 mm diameter • Simple, Retrievable • Inexpensive • Various size (2 to 10 mm) • 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 • • 3 D 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 M 197.

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