Guiding catheter having shape-retentive distal end
A guiding catheter has a proximal portion constructed of a tubular braid and a shape-retentive distal portion including a superelastic hypotube cut to define particular mating, support, shape-retentive and flexibility characteristics. A tubular liner extends through both of the tubular braid and the hypotube. The hypotube is joined to the braid using a mechanical interlock that has high torque transfer from the braid to the hypotube. A short portion of high stiffness polymer tube is provided at a joint between the braid and the hypotube. A polymeric outer jacket is provided over the proximal and distal portions, including the polymer tube. The jacket is heat set over the hypotube to remove residual stress.
1. A catheter, comprising:
a) a tubular braided first portion having proximal and distal ends;
b) a tubular second portion having proximal and distal ends, the proximal end of the second portion coupled to the distal end of the first portion and having increased flexiblity in at least one direction relative to the first portion; and
c) a joint at a butt of the distal end of the first portion and the proximal end of the second portion, the joint having proximal, central, and distal joint segments,
the proximal and distal joint segments having a flexural modulus one-half to two-thirds that of a flexural modulus of the central segment.
2. The catheter of claim 1 , further comprising:
a jacket over the joint, the jacket including a lower durometer resin at the proximal and distal joint segment, and a higher durometer resin at the central joint segment.
3. The catheter of claim 1 , further comprising:
a high durometer extrusion over the central joint segment; and
a resin jacket over the proximal, central and distal joint segments and the extrusion.
4. The catheter of claim 1 , wherein:
the proximal and distal joint segments having a kink radius one-half to two-thirds of a kink radius of the central joint segment.
5. The catheter of claim 4 , wherein:
the kink radius is a minimum of 3 mm.
6. The catheter of claim 1 , wherein:
during bending centered at the joint, the proximal and distal segments undergo higher deformation than the central segment undergoes.
7. The catheter of claim 1 , wherein:
during bending centered at the joint, the central segment remains relatively more rigid than the proximal and distal segments.
8. The catheter of claim 1 , wherein:
the proximal and distal joint segments are jacketed in a low durometer resin, and the central joint segment is jacketed in a relatively higher durometer resin that the lower durometer resin.
9. The catheter of claim 8 , wherein:
the low durometer resin has a durometer of 60 A to 55 D durometer.
10. The catheter of claim 9 , wherein:
the higher durometer resin has a 10 to 60 durometer higher than the low durometer resin.
11. The catheter of claim 1 , wherein:
the central segment is reinforced with an adhesive, and the proximal, central and distal segments are then covered in an elastomeric resin.
12. The catheter of claim 1 , wherein:
the central segment is provided with a tubular extrusion or wrap, and the proximal, central and distal segments are then covered in an elastomeric resin tube or wrap.
13. The catheter of claim 12 , wherein:
the tubular extrusion or wrap is made of polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxy (PFA), ethylene tetrafluoroethylene (ETFE), polyethylene terephthalate (PET), and/or polyetherether-ketone (PEEK) polymers.