US-20260124437-A1 - EXPANDABLE DILATOR

US20260124437A1US 20260124437 A1US20260124437 A1US 20260124437A1US-20260124437-A1

Abstract

An expandable dilator for use with an expandable sheath includes a shaft having a tapered distal tip, a body, a proximal end, and a lumen extending longitudinally from the distal tip to the proximal end. The expandable dilator includes an expansion mechanism extending radially outward from the outer surface of the shaft. When the expandable dilator is withdrawn proximally into the expandable sheath, the expansion mechanism engages the distal end of the sheath and expands the sheath as the expansion mechanism moves proximally through the sheath.

Inventors

Daniel Presteng
James M. Anderson
John M. Edgell

Assignees

BOSTON SCIENTIFIC SCIMED, INC.

Dates

Publication Date: 20260507
Application Date: 20260105

Claims (20)

1 . A method of using a dilation system, comprising: advancing a tapered distal tip of an expandable dilator through a lumen of an expandable sheath to a position distal of the expandable sheath, the expandable sheath including one or more folds extending longitudinally from a distal end to a proximal end in a folded configuration, and the expandable dilator comprising: a shaft including the tapered distal tip; an expander positioned within a recess formed in the tapered distal tip, the expander having a first outer diameter when positioned within the recess than is less than an outer diameter of the shaft; and at least one tether extending proximally from the expander within a lumen of the shaft; pulling the at least one tether proximally to shift the expander proximally out of the recess, thereby causing the expander to shift to a second outer diameter larger than the first outer diameter; and withdrawing the expander through the expandable sheath, thereby causing the one or more folds to shift from the folded configuration to an expanded configuration.
2 . The method of claim 1 , wherein the expander is a flexible ring extending circumferentially around the tapered distal tip.
3 . The method of claim 1 , wherein the expander includes a plurality of protrusions extending radially outward from an outer surface of the expander.
4 . The method of claim 3 , further comprising: prior to withdrawing the expander, rotating the shaft to align one or more of the plurality of protrusions with the one or more folds.
5 . The method of claim 3 , wherein the plurality of protrusions are ridges extending longitudinally along the outer surface of the expander.
6 . The method of claim 1 , wherein the at least one tether extends from the expander outside of the shaft proximally into an opening in the shaft and then proximally within the lumen.
7 . The method of claim 6 , wherein the at least one tether includes two tethers fixed to opposite sides of the expander, wherein the opening in the shaft includes two openings disposed on opposite sides of the shaft, wherein each tether extends into one of the two openings.
8 . The method of claim 6 , wherein the opening is disposed on the shaft such that when the flexible ring is pulled proximally, the opening is adjacent a proximal end of the flexible ring.
9 . The method of claim 1 , wherein withdrawing the expander through the expandable sheath includes translating the shaft proximally within the expandable sheath.
10 . The method of claim 1 , wherein the shaft includes a knob disposed at a proximal end of the shaft, the at least one tether being fixed to the knob.
11 . The method of claim 10 , wherein pulling the at least one tether proximally includes manipulating the knob relative to the shaft to pull the at least one tether proximally.
12 . The method of claim 11 , wherein the knob is rotatable relative to the shaft.
13 . The method of claim 11 , wherein the knob is axially translatable relative to the shaft.
14 . The method of claim 1 , further comprising: after shifting the one or more folds to the expanded configuration, withdrawing a medical device disposed distal of the expandable sheath into the lumen of the expandable sheath.
15 . A method of using a dilation system, comprising: advancing an expandable dilator into a lumen of an expandable sheath, the expandable sheath including one or more folds extending longitudinally from a distal end to a proximal end in a folded configuration, and the expandable dilator comprising: a shaft including a tapered distal tip, a hub coupled to a proximal end of the shaft, and at least one expandable member disposed proximal the tapered distal tip, wherein the at least one expandable member is biased toward a radially expanded configuration and is configured to be maintained in a compressed configuration when the expandable dilator is disposed within the lumen of the expandable sheath, wherein in the compressed configuration an outer diameter of the at least one expandable member is equal to or less than an outer diameter of the shaft; advancing the expandable dilator distally relative to the expandable sheath until the at least one expandable member is disposed distal of the distal end of the expandable sheath, thereby shifting the at least one expandable member to the radially expanded configuration, wherein in the radially expanded configuration the outer diameter of the at least one expandable member is greater than the outer diameter of the shaft; and thereafter, withdrawing the expandable dilator through the expandable sheath, thereby causing the one or more folds to shift from the folded configuration to an expanded configuration.
16 . The method of claim 15 , wherein the hub includes a visible marker aligned with an expandable member of the at least one expandable member.
17 . The method of claim 16 , further comprising: prior to withdrawing the expandable dilator, rotating the shaft to position the expandable member aligned with the visible marker in alignment with a fold of the one or more folds.
18 . The method of claim 15 , wherein the at least one expandable member includes a radiopaque material.
19 . The method of claim 15 , wherein the at least one expandable member includes as many expandable members as there are folds in the expandable sheath.
20 . The method of claim 15 , wherein the at least one expandable member is self-biased toward the radially expanded configuration.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. application Ser. No. 18/742,240, filed Jun. 13, 2024, which claims the benefit of priority of U.S. Provisional Application No. 63/472,863 filed Jun. 14, 2023, the entire disclosure of which is hereby incorporated by reference. TECHNICAL FIELD The disclosure pertains to medical devices and more particularly to expandable introducers and dilators, and methods for using such medical devices. BACKGROUND A wide variety of medical devices have been developed for medical use including, for example, medical devices utilized to deliver and implant artificial heart valves. These medical devices may be used in a variety of implantation procedures, and are manufactured and used according to any one of a variety of different methods. Of the known medical devices and methods, each has certain advantages and disadvantages. There is an ongoing need to provide alternative medical devices as well as alternative methods for manufacturing and using the medical devices. SUMMARY This disclosure provides design, material, manufacturing method, and use alternatives for medical devices. An example expandable dilator includes a shaft having a tapered distal tip, a body, a proximal end, and a lumen extending longitudinally from the tapered distal tip to the proximal end, the shaft including a cutout through a sidewall of the shaft adjacent the tapered distal tip, and a slit extending through the sidewall and extending from the cutout to the proximal end, an expander positioned within the cutout, the expander having an outer diameter larger than an inner diameter of the lumen such that a portion of the expander extends through the cutout, the expander including a tether fixed to the expander and extending through the lumen and exiting out the proximal end of the shaft, and wherein pulling the tether proximally moves the expander proximally through the shaft such that the expander separates opposing edges of the slit as the expander moves proximally through the shaft. Alternatively or additionally to the embodiment above, a proximal end of the tether is fixed to a knob coupled to the proximal end of the shaft, the knob configured to pull the tether and the expander proximally through the shaft. Alternatively or additionally to any of the embodiments above, the knob is configured to be pulled proximally away from the proximal end of the shaft. Alternatively or additionally to any of the embodiments above, the knob is coupled to the shaft with a frangible connector that is breakable with a twisting or pulling force. Alternatively or additionally to any of the embodiments above, the knob is rotatably coupled to the proximal end of the shaft, and the tether is fixed to the knob such that rotation of the knob relative to the shaft in a first direction winds the tether onto the knob as the expander is pulled proximally through the lumen. Alternatively or additionally to any of the embodiments above, the shaft includes a plurality of channels extending longitudinally along an entirety of the shaft from a proximal end of the tapered distal tip. An example dilation system includes the above expandable dilator and an expandable sheath having a distal end, a proximal end, a lumen extending therebetween, and at least one fold extending longitudinally from the distal end to the proximal end, each fold defined by a circumferential overlap of material forming the expandable sheath, the expandable sheath including a distal ring configured to hold the expandable sheath in a compressed configuration, the distal ring having a longitudinal slit disposed over the fold, the distal ring biased in a closed configuration and expandable to an expanded configuration in which the slit is expanded when the expandable dilator is disposed within the expandable sheath with the expander positioned distal of the distal end of the expandable sheath, and the expander of the expandable dilator is pulled proximally, thereby allowing the fold to unfold and expand an inner diameter of the expandable sheath. Another example dilator for use with an expandable sheath includes a shaft having a tapered distal tip, a proximal end, a flexible ring disposed around the tapered distal tip, the flexible ring configured to be moved axially from the tapered distal tip onto the shaft, the flexible ring having a plurality of protrusions extending radially outward from an outer surface of the flexible ring, and at least one tether having a distal end fixed to the flexible ring and a proximal end extending axially along an outer surface of the tapered distal tip and into an opening in the shaft, the tether extending through a lumen of the shaft, wherein the proximal end of the at least one tether extends proximally out of the proximal end of the shaft. Alternatively or additionally to the embodiment above, the at least one tether includes two tethers fixed to opposite sides of the flexible ring, wherein the op