US-12623062-B2 - Radial access balloon catheter

Abstract

Discussed herein are various embodiments related to a catheter assembly. The catheter assembly can include a catheter body extending between a proximal portion and a distal portion. The catheter body can include a sleeve and a hypotube, connected by at least one bond site, and separated by a floating gap. The hypotube can include at least one flow opening extending from the hypotube lumen to a stagnation zone, configured to permit flow between the stagnation zone and the hypotube lumen.

Inventors

• Michael Reynolds
• Simon Davis

Assignees

• SURMODICS MD, LLC

Dates

Publication Date

20260512

Application Date

20220901

Claims (20)

1. 1 . A catheter assembly comprising: a catheter body extending between a proximal portion and a distal portion, the catheter body including: a sleeve extending between the proximal and distal portions, wherein the sleeve includes a sleeve lumen; a hypotube having a hypotube lumen, the hypotube extends between the proximal and distal portions and is received within the sleeve lumen; at least one bond site connecting the sleeve to the hypotube, wherein the hypotube and the sleeve are spaced forming a floating gap distal to the at least one bond site, and wherein the hypotube includes at least one flow opening extending from the hypotube lumen to the floating gap, and the at least one flow opening is configured to permit flow between the floating gap and the hypotube lumen; wherein the sleeve includes at least one floating segment and one or more bond sites along the catheter body, wherein the at least one floating segment of the sleeve is moveable relative to the hypotube, and the one or more bond sites of the floating sleeve are interconnected with the hypotube.
2. 2 . The catheter assembly of claim 1 , further comprising a stagnation zone along at least a portion of the floating gap.
3. 3 . The catheter assembly of claim 1 , wherein the floating gap is proximate the at least one bond site.
4. 4 . The catheter assembly of claim 1 , wherein the at least one flow opening is positioned adjacent to the at least one bond site.
5. 5 . The catheter assembly of claim 1 , wherein the at least one flow opening comprises a plurality of flow openings arranged in a spiral around the hypotube.
6. 6 . The catheter assembly of claim 1 , wherein the at least one flow opening is configured for movement of fluid therethrough.
7. 7 . The catheter assembly of claim 1 , further comprising a balloon fluidly connected to the distal portion of the catheter body.
8. 8 . The catheter assembly of claim 7 , wherein the balloon is actuatable between an expanded state and a collapsed state.
9. 9 . The catheter assembly of claim 8 , wherein when the balloon is actuated between the expanded state and the collapsed state, the least one flow opening is configured to expel fluid.
10. 10 . The catheter assembly of claim 7 , wherein the at least one flow opening is configured to allowing fluid flow therethrough during inflation of the balloon.
11. 11 . The catheter assembly of claim 7 , wherein the at least one flow opening is configured to allowing fluid flow therethrough during deflation of the balloon.
12. 12 . The catheter assembly of claim 7 , wherein the at least one flow opening is configured to allowing fluid flow therethrough during priming of the assembly.
13. 13 . The catheter assembly of claim 1 , wherein the at least one flow opening is configured to reduce buildup of bubbles in a stagnation zone.
14. 14 . The catheter assembly of claim 1 , wherein the at least one flow opening is configured to encourage fluid flow in a stagnation zone.
15. 15 . The catheter assembly of claim 1 , wherein the at least one flow opening each comprise a diameter of less than about 0.20 mm.
16. 16 . The catheter assembly of claim 1 , wherein the at least one flow opening each comprise a circular cross-section.
17. 17 . The catheter assembly of claim 1 , wherein the at least one flow opening each comprise a non-circular cross-section.
18. 18 . The catheter assembly of claim 1 , wherein the at least one flow opening is situated about one third of the way along the hypotube from the proximal portion.
19. 19 . The catheter assembly of claim 1 , wherein the hypotube comprises a spiral cut.
20. 20 . The catheter assembly of claim 19 , wherein the spiral cut comprises a continuous cut around an external surface of the hypotube.

Description

PRIORITY APPLICATION This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 63/239,717, filed Sep. 1, 2021, the content of which is incorporated by reference in its entirety. TECHNICAL FIELD This document pertains generally, but not by way of limitation, to catheter assemblies, or more particularly, to balloon catheters. BACKGROUND Catheters are used in a variety of medical procedures to conduct therapeutic or diagnostic functions within a patient. For instance, catheters are used for delivery of medications fluids or other therapies to specified locations in the patient. In other examples catheters conduct diagnostic procedures, withdraw fluids for testing, or drain fluids from the patient. Balloon catheters are a variety of catheter. In some examples, a balloon catheter includes an elongated shaft with an inflatable balloon proximate to an end of the shaft. In use, the catheter is inserted and advanced, for instance with a guidewire to position the balloon at a location for treatment (e.g., a diseased vessel). The balloon and the catheter are filled with an inflation fluid in preparation for inflation of the balloon. Once inserted, the balloon is expanded with the inflation fluid to dilate a restriction, for instance a narrow opening or passage within a body. The fluid flows down the length of the catheter assembly to the balloon during inflation. Dilation catheters treat vascular stenosis by inflating a balloon at a distal end of the catheter within the stenoses portion of the blood vessel to mechanically expand the blood vessel and restore blood flow. The catheter is inserted into the vascular system through an access site and navigated through the vasculature to reach the stenoses blood vessel. The access site is typically in the groin region due to close proximity and easy navigation to commonly stenosed regions of the vasculature such as the lower extremities and the coronary region. While groin access sites can simplify the procedure itself, the groin access site can present significant post-operation challenges. In particular, groin access sites are more likely to bleed uncontrollably and require an overnight hospital stay. SUMMARY The device being patented is a “radial access” balloon dilation catheter that can be navigated from a radial access site in the wrist or arm to reach stenosed regions throughout the body including in the lower extremities. In order to reach from the access point to the treatment sites, the radial access catheter is much longer than conventional dilation catheters (about 250 cm vs about 100 cm in length), which presents a number of challenges unique to these devices. The primary challenge is maintaining sufficient stiffness at the distal end of the catheter for easy navigation of the catheter through the vasculature while having sufficient flexibility to navigate tight bends in the vasculature. The “floating” spiral-cut hypotube design is intended to address these challenges by providing sufficient axial stiffness to allow easy navigation, while allowing extra flexibility to permit navigation of tight bends. The floating hypotube is fixed to the outer shaft of the catheter at the proximal end and at a mid-point of the shaft, while the remainder of the hypotube is allowed to “float” within the outer shaft. The floating construction allows the outer shaft to deflect further than the stiffer hypotube thereby allowing a higher effective bend radius for the catheter shaft. The present inventors have recognized, among other things, that a problem to be solved can include regulating fluid flow through balloon catheters. In order to provide a “floating” hypotube, the hypotube is attached to the outer shaft at the proximal end and at a mid-point while the regions between the attachment points and the distal end of the hypotube “float” within the outer shaft. This construction creates can be provide challenges when flushing or inflating/deflating the dilation catheter. Prior to insertion of the dilation catheter into the body, the catheter shaft is flushed with a saline solution to force air from the catheter shaft and test inflation of the balloon. The fluid is fed into the catheter through the hub at the proximal end of the catheter and passes through the hypotube exiting through the distal end of the hypotube before continuing to the distal end of the catheter. As the distal end of the catheter is not fixed to the outer shaft, air can become trapped in the “floating” region between the distal end of the hypotube and the midpoint attachment point of the shaft to the hypotube. This “stagnation zone” can likewise hinder deflation of the catheter as fluid is withdrawn from the catheter through the hypotube. The balloon of a balloon catheter is inflated or deflated by movement of fluid along the length of the catheter body. Such a catheter assembly includes in some examples a sleeve (such as an outer liner), a hypotube at least partially withi