US-20260124429-A1 - MULTI-LUMEN CATHETER CONTAINING INTEGRAL STRUT AND METHOD OF ITS MANUFACTURE

US20260124429A1US 20260124429 A1US20260124429 A1US 20260124429A1US-20260124429-A1

Abstract

A multi-lumen catheter shaft ( 55 ) includes a single piece strut ( 110 ) having a central portion defining a central lumen and a pair of opposing radial arms ( 116 a ), each defining a respective biased lumen ( 116 ). A first tubular layer ( 113 ) surrounds the strut, thus defining two opposing side lumens between the first tubular layer and the strut. The strut and first tubular layer may be separately or integrally formed. A second tubular layer ( 130 ) may be disposed around the first tubular layer, with an optional reinforcing layer ( 120 ) (e.g., a braided metallic mesh layer) disposed between the first and second tubular layers. Radial walls extending from the central portion of the strut may further subdivide the side lumens. Pull wires ( 10 ), activation wires, electrical conductors, and the like may be routed through the central, biased, and side lumens.

Inventors

Xiaoping Guo
Xuan Khieu

Assignees

ST. JUDE MEDICAL, CARDIOLOGY DIVISION, INC.

Dates

Publication Date: 20260507
Application Date: 20221027

Claims (20)

1 . A catheter shaft, comprising: a single piece strut having a central portion defining a central lumen extending therethrough and a pair of opposing arms extending radially away from the central portion, each of the pair of opposing arms defining a respective biased lumen extending therethrough; and a first tubular layer surrounding the strut and defining two opposing side lumens extending through the catheter shaft between the first tubular layer and the strut.
2 . The catheter shaft according to claim 1 , wherein the first tubular layer is integrally formed with the strut from a single polymeric material.
3 . The catheter shaft according to claim 1 , wherein the strut comprises a first polymeric material, the first tubular layer comprises a second polymeric material different from the first polymeric material, and the strut is bonded to the first tubular layer.
4 . The catheter shaft according to claim 1 , further comprising a second tubular layer surrounding the first tubular layer.
5 . The catheter shaft according to claim 4 , wherein a material of which the second tubular layer is formed has a lower critical solid-state thermal transition temperature than a material of which the strut is formed.
6 . The catheter shaft according to claim 4 , further comprising a reinforcing layer disposed between the first tubular layer and the second tubular layer.
7 . The catheter shaft according to claim 6 , wherein the reinforcing layer comprises a braided metallic mesh.
8 . The catheter shaft according to claim 1 , wherein a line extending through the biased lumens and the central lumen defines a deflection axis, a line extending through a center of the central lumen and perpendicular to the deflection axis defines a neutral axis, and an area moment of inertia of the strut about the neutral axis is less than or equal to an area moment of inertia of the strut about the deflection axis.
9 . The catheter shaft according to claim 8 , further comprising a pair of biasing ribbons positioned along the neutral axis equidistant from the deflection axis.
10 . The catheter shaft according to claim 9 , wherein the pair of biasing ribbons comprises a pair of metallic ribbons.
11 . The catheter shaft according to claim 1 , wherein the strut further comprises a pair of walls extending radially away from the central portion to the first tubular layer and dividing each of the two opposing side lumens into a respective pair of sub-lumens.
12 . The catheter shaft according to claim 1 , further comprising: a first pull wire extending through a first biased lumen; a second pull wire extending through a second biased lumen; and a loop-activating wire extending through the central lumen.
13 . The catheter shaft according to claim 12 , further comprising a plurality of electrical conductors extending through at least one of the two opposing side lumens.
14 . A method of manufacturing a catheter shaft, comprising: forming a single-piece strut having a central portion defining a central lumen extending therethrough and a pair of opposing arms extending radially away from the central portion, each of the pair of opposing arms defining a respective biased lumen extending therethrough; and forming a first tubular layer around the strut to define two opposing side lumens extending through the catheter shaft between the first tubular layer and the strut.
15 . The method according to claim 14 , wherein forming the single-piece strut and forming the first tubular layer around the strut comprise integrally forming the single-piece strut and the first tubular layer from a single polymeric material.
16 . The method according to claim 14 , wherein: forming the single-piece strut comprises forming the single piece strut from a first polymeric material; forming the first tubular layer comprises forming the first tubular layer from a second polymeric material different from the first polymeric material; and wherein the method further comprises bonding the first tubular layer to the single-piece strut.
17 . The method according to claim 14 , further comprising forming a second tubular layer around the first tubular layer.
18 . The method according to claim 17 , wherein a material of which the second tubular layer is formed has a lower critical solid-state thermal transition temperature than a material of which the first tubular layer is formed.
19 . The method according to claim 17 , further comprising forming a reinforcing layer between the first tubular layer and the second tubular layer.
20 . The method according to claim 14 , wherein the single-piece strut defines a deflection axis extending through the biased lumens and the central lumen and a neutral axis perpendicular to the deflection axis, and wherein an area moment of inertia of the strut about the neutral axis is less than or equal to an area moment of inertia of the strut about the deflection axis.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. provisional application No. 63/277,876, filed 10 Nov. 2021, which is hereby incorporated by reference as though fully set forth herein. BACKGROUND The present disclosure relates generally to catheters that are used in the human body. In particular, the present disclosure relates to an integral strut for use in multi-lumen catheters, including steerable catheters. Catheters are used for an ever-growing number of procedures. For example, catheters are used for diagnostic, therapeutic, and ablative procedures, to name just a few examples. Typically, the catheter is manipulated through the patient's vasculature and to the intended site, for example, a site within the patient's heart. The catheter carries one or more electrodes for conducting cardiac ablation, diagnosis, or the like, and may also contain additional positioning sensors usable to determine the position and/or orientation of the catheter within the patient's body. Because the path through the patient's vasculature to the intended site is often long and tortuous, steering forces typically must be transmitted over relatively great distances. Accordingly, it is desirable for a catheter to have sufficient axial (e.g., column) strength to be pushed through the patient's vasculature via a force applied at its proximal end (“pushability”). It is also desirable for a catheter to transmit a torque applied at the proximal end to the distal end (“torqueability”). Pushability and torqueability (collectively, “maneuverability”) permit a physician to manipulate a catheter to an intended site and then properly orient the catheter. It is also desirable for a catheter to have sufficient flexibility to substantially conform to the patient's vasculature and yet resist kinking as it does so. Kinking is often the result of a localized failure of the material of the catheter when localized stresses exceed the yield strength of the material. To provide pushability, torqueability, flexibility, and kink resistance, many extant catheters are made of engineering polymer materials reinforced with metallic wire braiding plaits. The characteristics of pushability, torqueability, flexibility, and kink resistance are often in tension with one another, however, with improvements in one requiring compromises in others. Steerable and variable-radius loop catheters are also known. One example of such a catheter is the Advisor™ VL Circular Mapping Catheter, Sensor Enabled™ (Abbott Laboratories, Abbott Park, IL). BRIEF SUMMARY Disclosed herein is a catheter shaft, including: a single piece strut having a central portion defining a central lumen extending therethrough and a pair of opposing arms extending radially away from the central portion, each of the pair of opposing arms defining a respective biased lumen extending therethrough; and a first tubular layer surrounding the strut and defining two opposing side lumens extending through the catheter shaft between the first tubular layer and the strut. In embodiments of the disclosure, the first tubular layer is integrally formed with the strut from a single polymeric material. In alternative embodiments of the disclosure, the strut is made of a first polymeric material, the first tubular layer is made of a second polymeric material different from the first polymeric material, and the strut is bonded to the first tubular layer. A second tubular layer may surround the first tubular layer. It is contemplated that the critical solid-state thermal transition temperature of the material used to form the second tubular layer will be lower than the critical solid-state thermal transition temperature of the material used to form the first tubular layer and/or the strut. Optionally, a reinforcing layer, such as a braided metallic mesh, may be disposed between the first tubular layer and the second tubular layer. A line extending through the biased lumens and the central lumen defines a deflection axis, while a line extending through a center of the central lumen and perpendicular to the deflection axis defines a neutral axis. It is desirable for an area moment of inertia of the strut about the neutral axis to be less than or equal to an area moment of inertia of the strut about the deflection axis. In this regard, a pair of biasing ribbons, such as metallic ribbons, may be positioned along the neutral axis equidistant from the deflection axis. The strut may also include a pair of walls extending radially away from the central portion to the first tubular layer, thus dividing each of the two opposing side lumens into a respective pair of sub-lumens. It is also contemplated for the catheter shaft to include a first pull wire extending through a first biased lumen; a second pull wire extending through a second biased lumen; and a loop-activating wire extending through the central lumen. In still further embodiments of the disclosure, a plurality of electrical conduc