Distal tip for a delivery catheter
Distal tips for use with delivery catheters are disclosed that are configured to maintain complete engagement between the distal tip and a distal opening of a sheath component of the delivery catheter so as to prevent separation therebetween and/or to prevent fish-mouthing of a distal leading edge of the sheath component during in vivo use. Distal tips so configured realize one or more of the objectives of safer tracking of the delivery catheter through the vasculature, safe crossing of the delivery catheter through structural components of the vasculature and heart, such as through native valves, and safe removal of the delivery catheter post deployment.
1. A delivery catheter for endoluminal delivery of a prosthesis comprising:
a tubular sheath component defining a distal opening and distally extending first and second arched portions, wherein the distal opening is defined by and between the distally extending first and second arched portions;
an elongate inner shaft at least partially disposed within the sheath component; and
a distal tip attached to the inner shaft that engages with the distal opening of the sheath component when the delivery catheter is in a delivery configuration and disengages from the distal opening when the delivery catheter is in a deployment configuration, the distal tip defining a distal segment and a proximal segment that are demarcated by a proximally facing bearing surface that forms a radially extending circumferential ridge that continuously extends around the entire circumference of the distal tip,
wherein the circumferential ridge defines distally extending first and second valley portions that receive at least a crown of a corresponding first or second arched portion of the sheath component therein when the distal tip engages with the distal opening of the sheath component in the delivery configuration.
2. The delivery catheter of claim 1 , wherein the sheath component includes a distally facing bearing surface that is at least partially defined along a distal surface of the first and second arched segments to abut against the distal tip bearing surface within the corresponding first and second valley portions when the distal tip engages with the distal opening of the sheath component in the delivery configuration.
3. The delivery catheter of claim 2 , wherein bearing engagement between the first and second valley portions of the distal tip and the corresponding crowns of the first and second arched segments permits the distal tip to pivot or rock back and forth on the distally facing bearing surface of the sheath component.
4. The delivery catheter of claim 1 , wherein the distal segment of the distal tip is distally tapered and the proximal segment of the distal tip has a dome shape that is sized to be slidably receivable within the distal opening of the sheath component.
5. The delivery catheter of claim 1 , wherein the distal segment of the distal tip has a first radiopacity and the proximal segment of the distal tip has a second radiopacity.