Welding Systems Useful for Closure of Cardiac Openings

Abstract

A welding element is provided for applying heat, chemicals, pressure, or any combination thereof to tissues inside a patient's body, e.g., a patent foramen ovale. In one aspect, the welding element is connected to a radio frequency energy source and includes an electrode and a locator. The locator facilitates positioning of the welding element and is capable of moving from an open position to a clamping position. In another aspect, a needle is provided for transseptal puncturing before the application of heat. In yet another aspect, the welding element is configured as a coil. The welding element can be made of Nitinol.

What is claimed is: 
     
         1 . An intravascular device for treating a septal defect in a subject, the device comprising:
 a) a tissue welding element;   b) a hollow needle having a sharp distal tip and a proximal anchor and further having one or more prongs extending outwardly therefrom to immobilize the welding element within the septal defect;   c) a bore between the sharp distal tip and the proximal anchor;   d) a central cable slidably disposed within the bore, the central cable being attached to an energy source and having a distal pronged anchor to anchor the needle within the septal defect.   
     
     
         2 . The device according to  claim 1 , wherein the distal anchor of the central cable is movable from an open position to a clamping position. 
     
     
         3 . The device according to  claim 1 , wherein the distal anchor of the central cable is made of a shape memory material. 
     
     
         4 . A method for treating a septal defect by treating it with the device according to  claim 1 , the method comprising applying energy to the tissue surrounding the septal defect from the energy source through the tissue welding element. 
     
     
         5 . The method of  claim 4 , wherein the septal defect is a patent foramen ovale, and the tissue welded together is the septum secundum and the septum primum.