Method and apparatus for accessing the left atrial appendage

Abstract

Disclosed is an apparatus for facilitating access to the left atrium, and specifically the left atrial appendage. The apparatus may comprise a sheath with first and second curved sections that facilitate location of the fossa ovalis and left atrial appendage. The apparatus may further comprise tissue piercing and dilating structures. Methods are also disclosed.

1 . A transseptal access system, comprising a sheath, a dilator and a needle; wherein the sheath comprises:
 a first curved section shaped to abut an interior wall of a right atrium substantially opposite a septum between a right atrial appendage and a left atrial appendage and directed toward the septum;   the first curved section having an outer edge that defines a first proximal edge point, and a first distal edge point wherein the intersection between a tan ent drawn to the first curved section at the first proximal edge point and a tangent drawn to the first curved section at the first distal edge point, define a first angle and a first plane,   wherein the first angle is within the range of about 75 degrees to about 105 degrees,   wherein the needle is adapted to penetrate a fossa ovalis when the distal end of the dilator is advanced to contact the fossa ovalis,   further wherein the needle comprises one or more radially extensible blades adapted to be extended radially within the left atrium following penetration of the fossa ovalis by the needle such that the radially extended blades are adapted to expand the size of penetration of the fossa ovalis when the needle and one or more radially extended blades are withdrawn through the penetration of the fossa ovalis.   
     
     
         2 . The transseptal access system of  claim 1 , further comprising:
 a second curved section shaped to direct a distal end of the sheath toward a left atrial appendage;   the second curved section having an outer edge that defines a second proximal edge point, and a second distal edge point wherein the intersection between a tangent drawn to the second curved section at the second proximal edge point and a tangent drawn to the second curved section at the second distal edge point, define a second angle and a second plane,   wherein the angle between the first and second plane, defined as the acute angle between the normal to the first plane and the normal to the second plane, is within the range of about 75 degrees to about 105 degrees.   
     
     
         3 . The transseptal access system of  claim 1 , wherein the first angle is within the range of about 80 degrees to about 100 degrees. 
     
     
         4 . The transseptal access system of  claim 2 , wherein the second angle is within the range of about 80 degrees to about 100 degrees. 
     
     
         5 . The transseptal access system of  claim 1 , wherein the dilator comprises an inflatable balloon. 
     
     
         6 . The transseptal access system of  claim 1 , wherein the dilator is coated with PTFE. 
     
     
         7 . The transseptal access system of  claim 1 , wherein the needle is advanced by a biasing means. 
     
     
         8 . The transseptal access system of  claim 1 , wherein the dilator comprises a vacuum lumen to allow application of a vacuum to the fossa ovalis. 
     
     
         9 . The transseptal access system of  claim 1 , wherein the dilator includes at least one infusion port for infusing saline solution. 
     
     
         10 . The transseptal access system of  claim 1 , wherein the sheath comprises a vacuum lumen to allow application of a vacuum to the fossa ovalis. 
     
     
         11 . The transseptal access system of  claim 1 , wherein the sheath comprises a vacuum lumen to allow application of a vacuum to the fossa ovalis. 
     
     
         12 . The transseptal access system of  claim 1 , further comprising an ultrasound transducer for oscillating the needle at ultrasonic frequencies.