Dilation procedures with expandable dilation devices
An expandable dilation member may include a proximally-tapered portion to dilate a stricture. The dilation member may be distally advanced in an unexpanded state over a wire guide through the stricture. The dilation member may then be configured in an expanded state, where the dilation member has a longitudinal profile that includes the proximally-tapered portion. A handle assembly proximally pulls the dilation member in the expanded state. In response, the proximally-tapered portion engages with and biases the stricture. When biasing the stricture, the proximally-tapered portion exerts a plurality of different types of forces, including a shearing force, a radial force, and in some procedures, a torsional force. In some embodiments, the proximally-tapered portion has a continuous taper from a smallest diameter to a largest diameter. In other embodiments, the proximally-tapered portion has at least one constant-diameter portion longitudinally disposed in between the smallest diameter and the largest diameter.
1. A method comprising:
proximally moving a proximally-tapered portion of a dilation member through a stricture of a bodily structure providing a passageway;
dilating the stricture with the proximally-tapered portion in response to proximally moving the proximally-tapered portion through the stricture; and
rotating the dilation member while dilating the stricture with the proximally-tapered portion and proximally moving the dilation member through the stricture.
2. The method of claim 1 , wherein the proximally-tapered portion comprises a plurality of stages, wherein each of the plurality of stages has an associated length of constant diameter, and wherein the stages have different constant diameters from each other over their respective lengths.
3. The method of claim 2 , further comprising:
engaging the stricture with a stage of the plurality of stages over a length of constant diameter associated with the stage in response to proximally moving the proximally-tapered portion through the stricture.
4. The method of claim 3 , wherein the stage comprises a first stage and the length of constant diameter comprises a first length of constant diameter, the method further comprising:
engaging the stricture with a second stage of the plurality of stages over a second length of constant diameter associated with the second stage in response to proximally moving the proximally-tapered portion through the stricture, wherein the constant diameter over the second length is greater than the constant diameter over the first length.
5. The method of claim 3 , wherein the stage comprises a first stage and the length of constant diameter comprises a first length of constant diameter, the method further comprising:
engaging the stricture with a proximal taper of a second stage of the plurality of stages in response to proximally moving the proximally-tapered region through the stricture; and
in response to engaging the stricture with the proximal taper, deflating the dilation member before engaging the stricture with the second stage over a second length of constant diameter associated with the second stage; and
proximally withdrawing the dilation member from the bodily structure in response to deflating the dilation member.
6. The method of claim 1 , wherein the proximally-tapered portion comprises a continuously decreasing diameter of a length of the proximal portion in a proximal direction.
7. The method of claim 6 , wherein the proximally-tapered portion comprises an angle relative to a central axis of the dilation member in a range of 2 to 6.5 degrees.
8. The method of claim 1 , further comprising:
positioning a proximal end of the dilation member distally past a proximal end of the stricture by distally advancing the dilation member in an unexpanded state through the stricture until the proximal end of the dilation member is at a position distally past the proximal end of the stricture;
in response to positioning the proximal end of the dilation member, changing the dilation member from the unexpanded state to the expanded state.
9. The method of claim 1 , measuring a resistance to the proximally moving of the dilation member provided by the stricture by measuring, with a force gauge, an amount of longitudinal force proximally moving the elongate member.
10. The method of claim 1 , sensing, with at least one sensor attached to the dilation member, an amount of elongation of the dilation member in response to proximally moving the dilation member.
11. The method of claim 1 , wherein the dilation member comprises a dilation balloon.
12. The method of claim 1 , wherein the bodily structure comprises an esophagus of the patient.
13. The method of claim 1 , wherein the bodily structure comprises a pyloric sphincter.