PFO Presentation

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					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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posted:6/22/2012
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