Bidirectional Introducer Catheter

Abstract

A bidirectional introducer includes a dilator having a distal end portion that includes a first section having a distal first section end, a second softer section having a proximal second section end and a distal second section end and a third reinforced section having a proximal third section end, wherein a) the distal first section end is coupled to the proximal second section end and the distal second section end is coupled to the proximal third section end and b) i) at least a portion of the first section is characterized by a first rigidity and at least a portion of the second softer section is characterized by a second rigidity that is lower than the first rigidity and ii) at least a portion of the third reinforced section is characterized by a third rigidity that is higher than both the first rigidity and the second rigidity.

What is claimed is: 
     
         1 . A bidirectional introducer, comprising a catheter including:
 a sheath; and   a dilator located within and substantially coaxially with the sheath, the dilator having a distal end portion that includes a first section having a proximal first section end and a distal first section end, a second softer section having a proximal second section end and a distal second section end and a third reinforced section having a proximal third section end and a distal third section end, wherein a) the distal first section end is coupled to the proximal second section end and the distal second section end is coupled to the proximal third section end and b) i) at least a portion of the first section is characterized by a first rigidity and at least a portion of the second softer section is characterized by a second rigidity that is lower than the first rigidity and ii) at least a portion of the third reinforced section is characterized by a third rigidity that is higher than both the first rigidity and the second rigidity.   
     
     
         2 . The bidirectional introducer of  claim 1 , further comprising a guide wire located within and substantially coaxially with the dilator, wherein the guide wire can be moved relative to the dilator to increase a radius of curvature characterized by the distal end portion. 
     
     
         3 . The bidirectional introducer of  claim 2 , wherein the guide wire includes a soft hydrophilic tip and gradual stiffening. 
     
     
         4 . The bidirectional introducer of  claim 1 , wherein the sheath includes a manifold for introduction of a fluid. 
     
     
         5 . A kit of parts for assembly of a bidirectional introducer comprising a catheter including:
 a sheath;   a dilator having a distal end portion that includes at first section having a proximal first section end and a distal first section end, a second softer section having a proximal second section end and a distal second section end and a third reinforced section having a proximal third section end and a distal third section end, wherein a) the distal first section end is coupled to the proximal second section end and the distal second section end is coupled to the proximal third section end and b) i) at least a portion of the first section is characterized by a first rigidity and at least a portion of the second softer section is characterized by a second rigidity that is lower than the first rigidity and ii) at least a portion of the third reinforced section is characterized by a third rigidity that is higher than both the first rigidity and the second rigidity; and   a guide wire.   
     
     
         6 . The kit of parts of  claim 5 , wherein the guide wire is located within and substantially coaxially with the dilator, wherein the guide wire can be moved relative to the dilator to increase a radius of curvature characterized by the distal end portion. 
     
     
         7 . The kit of parts of  claim 6 , wherein the guide wire includes a soft hydrophilic tip and gradual stiffening. 
     
     
         8 . The kit of parts of  claim 5 , wherein the sheath includes a manifold for introduction of a fluid. 
     
     
         9 . A method of using a bidirectional introducer catheter, comprising:
 inserting a sheath, dilator and guide wire into a mammal;   partially withdrawing the guide wire with regard to the dilator to reversibly deform the dilator;   partially withdrawing the dilator to reposition the dilator with regard to the sheath;   at least partially withdrawing the sheath;   rotationally swinging the sheath into a reversed position;   reinserting the guide wire to reform the dilator; and   reinserting the sheath.