Expandable transluminal sheath
View Patent ↗Disclosed is an expandable transluminal sheath, for introduction into the body while in a first, low cross-sectional area configuration, and subsequent expansion of at least a part of the distal end of the sheath to a second, enlarged cross-sectional configuration. The distal end of the sheath is maintained in the first, low cross-sectional configuration and expanded using a radial dilatation device. In an exemplary application, the sheath is utilized to provide access for a diagnostic or therapeutic procedure such as ureteroscopy or stone removal.
1. A method of providing access to a body lumen comprising the steps of:
inserting a sheath into a body lumen; the sheath having an axially elongate sheath tube with a proximal region, a distal region, and a central through lumen;
advancing the sheath to a desired site within the body lumen;
occluding the central through lumen with a central obturator during the inserting and advancing of the sheath within the body lumen;
dilating the distal region of the sheath to an expanded diameter by inflating a balloon on the central obturator, thereby forming a substantially uniform diameter of the central through lumen throughout an entire length of the central through lumen, including the proximal region and the distal region;
collapsing the balloon of the central obturator by an action applied at the proximal end of said central obturator,
removing the central obturator from the sheath,
inserting a device into the central through lumen of the sheath and advancing it to the desired site,
performing a desired operation with the device, and
removing the sheath from the patient.
2. The method of claim 1 wherein the dilating is performed by attaching a liquid-filled inflation device to a balloon inflation port at the distal end of the central obturator and infusing fluid under pressure into the central obturator.
3. The method of claim 1 wherein the step of collapsing the central obturator comprises withdrawing a plunger on an inflation device to withdraw fluid from the central obturator.
4. The method of claim 1 wherein a guidewire is advanced to the desired site prior to inserting the sheath into the body lumen.
5. The method of claim 1 wherein the sheath is advanced over a previously placed guidewire, which guidewire is routed through a lumen in the dilator.
6. The method of claim 1 wherein the desired site is anatomically distal to the region where the desired operation is intended to be performed.
7. The method of claim 1 wherein the body lumen is a mammalian urinary tract.
8. The method of claim 1 wherein the desired site is the mammalian ureter.
9. The method of claim 1 wherein the sheath further comprises a transition zone comprising proximal and distal chevrons, the chevrons forming a substantially even zig-zag pattern with a substantially smooth gradual transition when undistorted.
10. The method of claim 1 wherein the sheath further comprises a non-expandable proximal region and a transition zone between the non-expandable proximal region and the distal region, the regions being fused together along edges of chevrons.
11. The method of claim 1 wherein the sheath further comprises longitudinal running flutes.
12. The method of claim 11 wherein the flutes reduce friction between an inner layer of the sheath and the instrumentation.