WO1999034849A1 - Catheter sheath introducer for reducing friction - Google Patents

Abstract

The invention relates to a catheter sheath introducer (10) for introducing one or more medical devices, such as guide wires or catheters which may include a tubular body (14) with distal ends, proximal ends, and a passage extending between the proximal and distal ends. The introducer also includes a housing (12) coupled to the proximal end of the tubular body, a seal (58) coupled to the housing tending to block the escape of fluids through the passage and the seal. The introducer may also include an opening mechanism for selectively causing the seal to open, thereby reducing friction resistance.

Description

CATHETER SHEATH INTRODUCER FOR REDUCING FRICTION

1. Technical Background:

The present invention relates generally to medical devices, and more particularly to devices and methods for reducing friction while introducing a medical device. 2. Discussion:

The present invention concerns apparatus for introducing various elongated medical devices into the body of a patient for treatment. Such medical devices include guidewires, optical fibers, ultrasound probes, and of course catheters of all types, including angioplasty, cryogenic, laser, diagnostic, thrombectomy or ablation catheters, or any combination of similar devices. Such medical devices are often introduced into the patient's body through a device specifically designed to do so, as in the present invention, which is generally known as a catheter sheath introducer. Of course, a catheter sheath introducer may be used for introducing any suitable devices, and not only catheters and accessories.

A catheter sheath introducer may be kept in place throughout a patient's hospital stay, yet each medical procedure often requires much less time. One of the main purposes of the catheter sheath introducer is to prevent fluids from escaping during the times between the medical procedures. Catheter sheath introducers generally may have a tubular basic body with distal and proximal ends and a passage or lumen extending between the ends, as well as a head having an openable seal near the proximal end. The seal tends to prevent the escape of liquids or other substances through the tubular body and outside the patient, and is usually formed by a membrane having one or more cuts that form several flaps. The membrane is generally made of pliable material, so that the flaps tend to resiliently give way to allow the introduction and withdrawal of a medical device. At the same time, the membrane material should be sufficiently firm, such that this seal tends to remain closed and block the passage effectively when the medical device is removed, despite internal pressure from inside the body. However, the seal membrane and its flaps tend to generate friction, resisting easy insertion or withdrawal of medical devices through the catheter sheath introducer. In addition, the medical device to be inserted through the catheter sheath introducer may not be entirely smooth. For example, a balloon catheter may be mounted with a stent, which is a metal mesh scaffold, crimped around the balloon. The stent, or any other surface features of the medical devices, may of course increase the friction present when advancing or withdrawing it through the catheter sheath introducer.

In addition, especially in the case of large diameter catheters and medical devices, the passage through the catheter sheath introducer must be very wide. Because it is desirable to ensure that the seal over such a wide passage remains closed when no medical device is inserted through it, the seal should preferably exert great resistance against pressure from inside the catheter sheath introducer. This increased resistance may for example be achieved by using a very thick seal membrane. Unfortunately, the friction caused by the seal against the introduction of a medical device through the seal will be greater, which is less desirable. An introducer device according to the present invention preferably incorporates a head defining a wide passage. Likewise, a seal gasket may be used which is sufficiently stiff to hold the wide passage closed against the internal pressures.

The novel arrangement of this present invention provides a unique mechanism for selectively forcing the seal gasket to open and remain open for some desired period of time, thus drastically reducing any friction that may resist introduction or withdrawal of any suitable medical device through the catheter sheath introducer. Of course, this opening mechanism is releasable whenever it is desirable to allow the seal to again close and block the passage.

Accordingly, by the way of the present invention, the catheter sheath introducer allows for the introduction of wider medical devices, with acceptable sealing when desired, yet minimizing friction when desired. In this way, the catheter sheath introducer of the present invention provides acceptable sealing during times between medical procedures, while allowing for low resistance to advancing and withdrawing medical devices during treatments.

The present invention thus preferably includes a system for enlarging the space available in the seal prior to the introduction of the medical device. This system for selectively holding the seal open can be incorporated in the same head of the catheter sheath introducer.

These and other various objects, advantages and features of the invention will become apparent from the following description and claims, when considered in conjunction with the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of an introducer device according to the present invention; Figure 2 is an enlarged perspective view of the device illustrated in Figure 1; Figure 3 is a partial cross-sectional view of the introducer device according to the present invention;

Figure 4 is a cross-sectional view of the introducer device of Figure 3, in an opened configuration; Figure 5 is an exploded perspective view of an alternative embodiment of an introducer device according to the present invention;

Figure 6 is a top view of a seal gasket from an introducer device according to the present invention; and

Figure 7 is a partial cross-sectional view of another alternative embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the present invention is merely illustrative in nature, and as such it does not limit in any way the present invention, its application or uses. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.

Figure 1 shows a perspective view of a device according to the present invention, namely an introducer 10. The catheter sheath introducer 10 consists of a housing 12 and a tubular basic body 14 defining a chamber 38. A pair of connectors 16 and 18 couple the housing 12 to an auxiliary tube 20 and the tubular body 14, respectively. The auxiliary tube 20 terminates in a manual valve 22, adapted to allow the injection of medications directly into the chamber 38, through the tubular body 14, and out the tubular body distal end 24. The manual valve may include a medication port 26, a valve lever 28, and an aspiration port 30. The housing may be made of three main parts, a housing body 32, an intermediate collar 40, and an end cap 46. The housing body 32 defines chamber 38, has a port 34 for connection to the auxiliary tube 20, and a mounting hole 36 for stabilizing the position of the housing 12. The intermediate collar 40 has a snap coupling 42 to affix the intermediate collar 40 to the housing body 32, and threads 44. And the end cap 46 has finger knurls 48 for facilitating turning the end cap 46 in engagement with the threads 44, a vent 50 for equalizing pressures within an end chamber 56 defined by the end cap 46, and introduction port 52 for allowing the introduction and withdrawal of medical devices through the introducer, and a cylindrical plunger 54 for manually actuating the seal of the housing 12. The seal can be formed by a gasket 58 having slits 62, which is held in position by an annular anchor 60.

Figure 3 shows an introducer according to one embodiment of the present invention with the gasket seal 58 in a closed state, while Figure 4 shows the same introducer with the plunger actuated to force the gasket seal 58 into an open state. Figure 5 shows another embodiment of an introducer 64 arranged according to the present invention, having a body 66, a seal gasket 68, an intermediate collar 70, and an end cap 72.

Figure 6 shows one possible arrangement of a seal gasket 58 having a pair of slits 74 which are angled through the gasket 58 to attain a shifted position 76 on the opposing side of the gasket 58.

Figure 7 depicts another embodiment of an introducer 78 according to the present invention, having a housing body 80, a tubular body 86, an intermediate collar 88 with a fmger flange 90, and an end cap 92. The housing body 80 has an auxiliary port 82, and a connector 84. The end cap includes a cylindrical plunger 94 and a spring 96. Introducer 78 further includes a seal gasket 98 having one or more slits 100.

After reading the above, several embodiments of devices corresponding to those according to the present invention will force themselves on the expert in the field. Although these have not been described here explicitly, they are considered to fall within the scope of the attached claims. Many other forms of actively or passively operated aids integrated with the device may be designed so as to increase the ease of operation. Also, other seals than balloons, bodies made of solid pliable material and membranes may be employed and it is in particular possible to employ each of, and other seals than the ones described here in the configuration illustrated in figure 5 in an integrated aid for the opening hereof, etc.

Claims

1. An introducer for introducing medical devices into the body of a patient, comprising: a tubular body with distal and proximal ends, defining a passage extending between the proximal and distal ends; a housing affixed to the proximal end of the tubular body; a seal coupled to the housing having a sealed state and an open state, wherein the seal is adapted in the sealed state to close and tend to prevent the escape of material through the passage in a proximal direction, and wherein the seal in the open state is at least partially open to allow the introduction or withdrawal of a medical device through the seal and along the passage; such that the seal tends to resiliently at least partially open if a medical device is forcibly introduced through the seal, and tends to resiliently close and return to the sealed state upon removal of such medical device; and an opening mechanism for selectively causing the seal to shift from the sealed state and at least partially open to allow the introduction or withdrawal of a medical device and reduce friction resistance, the opening mechanism being adapted to override the tendency of the seal to resiliently close and return to the sealed state.

2. The introducer as recited in Claim 1, wherein the seal is formed as a gasket having one or more slits.

3. The introducer as recited in Claim 1, further comprising an auxiliary tube communicating between the tubular body passage and a manually actuatable valve, for allowing the injection of treatment fluids through the tubular body.

4. The introducer as recited in Claim 1, wherein the opening mechanism further comprises a plunger coupled to the housing, which can be selectively actuated to shift the seal to and from the sealed state and the open state.

5. The introducer as recited in Claim 4, further comprising a retracting mechanism causing the plunger to resiliently tend to retract and allow the seal to resume the sealed state.

6. The introducer as recited in Claim 5, wherein the retracting mechanism comprises a spring.

7. The introducer as recited in Claim 4, wherein the opening mechanism includes a screw cap coupled with the plunger.