Percutaneous Closure of Patent Foramen Ovale Sponsors: Design Team: Kung Ming Jan, M.D., Ph.D. Ali Stern Judah Weinberger, M.D., Ph.D. Dmitry Oulianov Columbia University Medical Center Dolores Miranda Department of Cardiology Henry Qazi Project TA: Jeffrey Garanich, Ph.D. Safiya Arif The City College of New York / Department of Biomedical Engineering Fetal Circulation Prenatal oxygenation Fetal circulation of blood bypasses lungs. Oxygenated blood passes from right to left atrium through the foramen ovale (FO). Prenatal Septal Development •Septum primum and secundum overlap. •Septa create an opening to allow direct shunting of fetal blood. Neonatal Septal Development Following birth the P of each chamber changes. P changes force septum primum to close over septum secundum. In a period of 1-2 weeks 70% of population have fusion of septa primum and secundum. Atrial Septal Defect The condition in which the septa fail to seal over and remain patent is known as ASD. ASD is an opening (hole) between right and left atria. Patent Foramen Ovale PFO, a type of ASD, is a flap- like opening between the atrial septa primum and secundum Clinical Need PFO is present in 20-25% of the population PFO has been associated with: Migraines Cryptogenic strokes Systemic embolism Migraine Migraine is a vascular headache Over 2,500,000 people in the U.S. have at least one migraine weekly, with a lifetime prevalence of 18% PFO are related to Migraines if paradoxic embolism causes headache Cryptogenic strokes There are 700,000 strokes per year in the U.S. 30-40% of these are cryptogenic 40-70% of cryptogenic strokes are PFO related 84,000-196,000 strokes per year in the United States are by paradoxical embolism due to PFO Treatment Options Medical Treatment Open heart surgery to close the PFO Percuteneous closure of the PFO CardioSeal 2 Double Umbrella implant MP35N Framework Dacron Sizes: 17-33mm Amplazter Self expandable Short connecting waist Nitinol Wires Sizes: 4-38mm Amplazter Delivery Disadvantages Designed for ASD Large surface Area Thrombus formation Reduced Endothelialization Poor Apposition Device Fracture Device Embolization Required Specifications Seals PFO only Consists of two components Delivery unit Means of closure Size requirements Delivery size: 3 - 4 mm diameter Deployment size: 3.6 x 4.2 cm Seals area of 8 mm radius around PFO Biocompatibility Immunological response Thrombogenic response Single use Mechanical & Electrical Stability Electrical isolation Isolate main voltage source Prevent current leakage Current limits Direct current < 1 μA Alternating current < 0.4 μA Mechanical forces Structural flexibility Desired Specifications Easily operable Cost efficient Biodegradable Degradation time Particle size Visible by ultrasound Non-magnetic Device Evaluation In Vitro Reaction to environment Fatigue test Maneuverability Catheter-device integrity In Vivo* Dog testing Human testing *Evaluation may not be performed in the scope of the project Concepts Glue or collagen plugs Magnetic suturing Energy welding devices Staple pins/sutures Scaffold Clipping device Intra atrium device Coiled suturing device “Sutura” model Hooked Scaffold Implant Polyester scaffold Advantages: Material Degradation into H2O & CO2 Disadvantages : Material: too stiff for delivery Intra atrium device (IAD) Advantages: Minimal amount of foreign material in the body Does not require exact positioning Disadvantages: Material selection: Complicated knot delivery method Coiled needle Components: coiled needle, 16mm base unit Advantages: Does not require exact positioning Disadvantages: Complicated mechanics Requires electrical energy Complicated knot delivery method Sutura Model Suturing device Components: 2 retractable arms, thread attached, 2 needles, handle Advantages: Existing device provides successful mechanism Disadvantages: Complicated manufacturing Clipping Device Advantages: Procedure using the device is reversible in case of failure Simple deployment mechanism Disadvantages: Requires precision Material properties Acknowledgements Kung Ming Jan, M.D., Ph.D. Judah Weinberger, M.D., Ph.D. Columbia University Medical Center Department of Cardiology Project TA: Jeffrey Garanich, Ph.D. Robert Sommer, M.D., Ph.D.
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