Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/0043—Catheters; Hollow probes characterised by structural features
  • A61M25/005—Catheters; Hollow probes characterised by structural features with embedded materials for reinforcement, e.g. wires, coils, braids
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/10—Balloon catheters
  • A61M25/104—Balloon catheters used for angioplasty

Definitions

• This invention relates to catheters for coronary angioplasty, particularly over-the-wire dilatation catheters.
• Catheters are tube-like members that are inserted into the body for various medical reasons, some diagnostic and others therapeutic.
• catheters used for coronary angioplasty have an outer tube or shaft with a balloon near the distal tip. The catheter is threaded into the vasculature, with the balloon located within the stenosis. The balloon is then inflated to redistribute the plaque of the stenosis along the artery wall so that it does not block the artery.
• an attached stiffening wire extends through the shaft to the tip to aid in the insertion of the catheter into the arteries, which are twisted and tortuous.
• a separate inner tube, or lumen extends within the outer tube to hold the guidewire.
• the guidewire is fixed in place within the inner tube; when the catheter is an over-the-wire catheter, the guidewire is a separate unit which extends through the inner tube and out the open far end.
• the catheter must be sufficiently strong so that pushing the catheter at the user's end results in forward motion at the distal end.
• the catheter has an inner tube or lumen, it must be strong enough to avoid collapse when the catheter extends around a corner.
• a flexible tube structure for an endoscopic device is formed of a plurality of end-to-end tubular units.
• Bundy, et al. U.S. Patent No. 4,653,496, a helically wound coil having a concentric outer radial cutting cannula is disclosed for the removal of stenotic and occlusive lesions from the vascular system.
• the outer lumen of a balloon catheter includes a coil; the same is the case in Sharrock, U.S. Patent No. 4,368,730, issued January 18, 1983, which discloses a catheter-like introducer.
• the proximal end of the inner tube of a dilatation catheter has a stainless steel liner.
• a dilatation catheter has a regulating expanding device embodied in a connector having an
• interlumen made of a tightly wound polymer-coated metal coil.
• a generally fixed-wire catheter is disclosed.
• the inner lumen is formed of a suitable metal and has an outside diameter of about 0.014 to 0.035 inches.
• a core is movably and removably mounted inside the lumen.
• a small "guidewire” extends from the distal tip of the catheter in some embodiments. In others, it extends from the distal tip of the core. Because the Hess catheters are essentially fixed-wire systems, with a core designed particularly to fit the inner lumen, they are not available for use and insertion over a standard guidewire.
• the invention in one aspect is an over-the-wire catheter with a spring coil inner lumen which avoids problems associated with the prior art. It includes an outer shaft, a balloon attached to the outer shaft and adapted for inflation through the outer shaft, and a cylindrical inner tube comprised of a wound wire extending within the inner shaft, the inner tube being open at the distal end to form a lumen for a separate guidewire.
• the wound wire is preferably made of stainless steel flat wire, and the preferred dimensions for the flat wire are 0.0015 inches by 0.006 inches.
• the inner lumen is jacketed with a biocompatible polymer, preferably polyethylene.
• a lubricious coating is applied to the interior of the inner lumen, and the outer shaft may be made of more than one material to enhance both stiffness and flexibility, while maintaining a good-sized inflation lumen.
• Fig. 1 is a plan view of the entire catheter.
• Fig. 2 illustrates a transition zone between the proximal and the distal portion of the outer shaft of the catheter.
• Fig. 3 is a cross-section of the catheter taken at lines 3-3 of Fig 2.
• the catheter 1 of the present invention is shown generally in Fig. 1. It includes a tubular outer shaft 2, a generally cylindrical inflatable balloon 4, and an inner tube or lumen 6.
• the balloon is heat shrunk at its proximal end 8 to the outer shaft, and at its distal end 10 to the inner tube, about 2 mm back, from the distal tip 26 of the catheter.
• the balloon preferably has a 20 cm working length.
• the outer shaft and inner tube define a lumen 3.0 therebetween shown on Fig. 3, a cross-section of the catheter.
• This lumen is used for inflation of the balloon and is open to the interior 12 of the balloon.
• a Y-shaped manifold 14 of polycarbonate is attached to the outer shaft at the proximal end, via a transition zone of strain relief tubing 26 and 28 formed of polyethylene (preferably Rexene 1017) . It includes one arm 16 accessing the inflation lumen for inflation of the balloon.
• the manifold has a second arm 18 which accesses the guidewire lumen 20.
• Guidewire lumen 20 extends the length of the catheter within the inner tube 6. It is designed so that a guidewire (32 shown in dotted lines in Fig. 3) can be slidingly inserted therethrough.
• the distal end 26 of the inner tube 6 is open so that the guidewire can be extended through and out the distal end of the catheter.
• the inner tube i.e., the "spring inner lumen” is comprised of a helically wound coil of a biocompatible material.
• the wire from which the coil is wound is preferably a flat wire, which gives the inner tube advantageous characteristics.. In particular, it provides a smoother surface so that a guidewire (particularly a standard one with round wire) can be easily slid through. Because of the relatively large, mutually-contacting surface of adjacent coils of flat wire, axial strength and stiffness is greater than in the case of
• the flat wire is formed of stainless steel (metal is preferred because it does not deform as do most polymers used for tubing) with dimensions of about 0.0015 by 0.006 inches. These dimensions appear to maximize axial strength and flexibility while maintaining desired catheter dimensions. However, other sizes can be used such as those ranging from about 0.001 to 0.003 inches in thickness and about 0.004 to 0.001 inches in width.
• the inner lumen has a heat shrunk jacket 34 formed of a low density polyethylene, such as Rexene 1017.
• a marker band is located at the center of the balloon, is formed of gold, and is heat shrunk into place by the polyethylene jacket.
• a lubricious material such as EnhanceTM silicone coating may be coated on the inner surface to enhance handling of the guidewire.
• the entire spring coil, before it is wound or jacketed, may be coated with other materials such as TeflonTM to enhance lubricity or provide other advantages. In some embodiments, the spring coil has been plated with gold.
• the inner diameter of the inner tube is about 0.017 to 0.019 inches, and the outer diameter .of the coil itself is about 0.022 inches.
• the overall diameter of the inner tube with jacket is about 0.024 to about 0.025 inches.
• the outer shaft 2 is preferably formed of a biocompatible flexible material such as those known in the art for use in catheters. Particular materials can be polyimides, poly thylenes, and the like. In the preferred embodiment, two materials are used.
• the proximal portion 22 of the shaft- usually about 105 cm long, is formed of polyethylene
• SUBSTITUTE SHEET terepthalate preferably Traytuf PET #7200c, and the distal 28 cm or so of the shaft, 24, is formed of polyethylene, preferably Rexene 1017.
• the joint.36 between the two portions of the shaft which is about 5 mm long in the preferred embodiment, is illustrated on Fig. 2; the two portions are overlapped and joined by a biocompatible adhesive such as cyanocrylate.
• the dual materials are included because PET forms a stiffer shaft than the polyethylene; it provides a stiff proximal end where the catheter is pushed by the user.
• the polyethylene distal shaft provides more flexibility for a more easily-steerable tip; in addition, the profile of the polyethylene portion is kept smaller for ease of tracking in the coronary vessels.
• the inner diameter of the PET outer shaft is preferably about 0.034 inches, while the outer diameter is preferably about 0.042 inches.
• the polyethylene portion in contrast, has an inner diameter of about 0.031 inches and an outer diameter of about 0.038 inches.

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• 1992
  • 1992-09-23 WO PCT/US1992/007948 patent/WO1993005842A1/en not_active Application Discontinuation
  • 1992-09-23 EP EP92921019A patent/EP0605615A1/de not_active Withdrawn

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