FIELD OF THE INVENTION

The present invention relates generally to apparatus and methods for delivering instruments and/or agents during a medical procedure, and, more particularly, to valves and hubs for guide sheaths, catheters, and other tubular devices for accessing body lumens and/or for delivering instruments into body lumens of a patient, and to methods for making and using them.

BACKGROUND

There are many medical procedures where a guidewire, catheter, lead, and/or other medical device may be introduced into a patient's body cavity, recess, vessel, organ, and/or other body lumen. In many of these procedures, a delivery sheath, an access or guide catheter, or other tubular member including a valve on a proximal end thereof may be used to facilitate introducing medical devices into and through a lumen of the tubular device. It is generally desirable for the valve to provide a substantially fluid tight seal between the tubular device and the medical devices introduced therethrough, e.g., for the purpose of hemostasis, infusion of therapeutic or diagnostic agents, and the like.

With the advent of many large profile vascular access therapies (examples include percutaneous valve replacement systems, larger pulmonary vein isolation systems, and the like), the need for improved valve performance has been increasing. Current state of the art valves generally perform well for smaller profile medical devices. For example, the demands on a valve in a smaller access device, e.g., to seal around medical devices having sizes up to 8.5 French (2.8 mm), is much less as compared to an access device where the valve needs to seal over a range of devices up to ten French (10 Fr; 3.3 mm) or higher. While the list of problems with state of the art valves is long, the most significant problems are: 1) the inability to seal on a smaller device (such as a guidewire) after removal of a larger device (such as an ablation catheter), 2) the inability of the valve design to withstand prolonged use and wear (it may seal at the beginning at the beginning of a procedure but not over time as devices are removed and inserted), 3) high friction that is generally undesirable for the operator as well as contributing to valve wear and/or deterioration, and 4) complexity where multiple valve components are used serially and more complex operations are required.

By way of example, a cross-slit valve is a time-tested valve design used for many vascular access products that is simple and—in the case of smaller access devices—effective. For such valves, a pair of slits may be provided that extend entirely through the valve from opposite sides, crossing through each other to create a point or line that acts a subsequent sealing surface for devices that are passed through the valve. In general, the cross-slit valve performs well in positive and negative pressure conditions with nothing passed through the valve (the faces of each slit seal on themselves under the deflection that comes during positive or negative pressure).

However, such valves usually fail when a large device is placed through that causes the sidewalls of the material of the passage between the two slits to stretch beyond their limit. This leads to tearing or plastic deformation of the valve material or both. While the valve may continue to seal on the larger device (frequently not), it will not seal on smaller devices and, frequently, the tear prevents closure of the slits thus causing leaks in positive and negative pressure with nothing across the valve. Of very particular concern is air ingress, which may occur when a device is moved in or out or during aspiration from an access side port (a frequent occurrence for a host of reasons).

Moreover, most minimally invasive procedures require use of multiple devices of various sizes. For example, access is generally preserved with a guidewire during device exchanges and, over time, the valve may fail to maintain a seal after removal of secondary devices. In PVI (pulmonary vein isolation) cases, the primary ablation catheter is often removed and then mapping or touch-up devices are used (also frequently in conjunction with a guidewire).

For specific reference, state of the art elastomeric materials have a maximum elongation in the range of 1100% in softer materials (which are ideal for some purposes and problematic for others) and 500% or less in harder materials. In a cross-slit valve, the point or axis/line formed from the cross-slit must expand from a point surface diameter of theoretically zero to the largest sized device to go through (e.g., a dilator). While some hysteresis at the central point can prevent tearing, the elongation required to expand from this small effective diameter (e.g., around 0.005″ (0.125 mm) to account for hysteresis prior to tearing) to that of say a 13 French (4.3 mm) dilator would require an elongation of over 3000%.

Valve performance in traditional valve designs has improved somewhat over the years as new or improved elastomers have come on to the market, both silicones as well as other natural and synthetic elastomers. However, those improvements are less and less, e.g., as very small increases in elongation, tear resistance, and the like may make little fundamental impact on valve performance. Some additional improvements have been made by incorporating multiple valves serially in a hub, but that adds complexity and new failure points.

Thus, sealing on small and large devices, particularly in the order where small devices must be inserted after use of a larger devices is an ongoing unmet clinical need of significant value.

SUMMARY

The present invention is directed generally to apparatus and methods for delivering instruments and/or agents during a medical procedure. More particularly, the present invention is related to valves and/or hubs for guide sheaths, catheters, and other tubular devices for accessing and/or delivering instruments into body lumens of a patient, and to methods for making and using them.

The ideal valve is a single part construction (for design robustness and manufacturability) that has one or more elements optimized for sealing in an empty condition and for sealing on secondary devices placed through/across the valve such that the valve material does not tear or otherwise deteriorate throughout its use and will continue to reliably seal on a range of secondary device diameters independent of the order of device usage The ideal valve minimizes friction and is ideally compatible with preferred lubricants. The ideal valve also makes insertion easy (e.g., is self-centering) both for ease of use and reduction in risk of damage to the valve.

The following disclosure describes exemplary valves and hubs for tubular devices that include one or more sealing elements for an “empty condition” (defined here as referring to when no device is introduced through or across the valve) and an additional but integral element/space for sealing on secondary devices, e.g., in a single construction. The empty condition sealing elements are generally accomplished with a cross-slit design where the cross-slit depths fall short of reaching each other, thus preserving a middle space without cross-slits for a secondary sealing element/space. A lumen or connecting hole may then be cut or otherwise formed between the cross-slits in a way that does not cut into the slit sidewalls near the faces (the two broad faces of the valve that are open to the outside of the device and this inside of the device) but fully connects the cross-slits to each other.

In an exemplary embodiment, unless directly formed in the valve prior to the cross-slits, the connecting hole may be formed by carefully bending/stretching/compressing or otherwise forming or moving the valve so that the hole cutting element can cut a hole only in the middle portion without cutting into the slit sidewalls at or near the faces. Thus, in the natural/non-bent condition, the connecting hole is otherwise concealed from view (unless transparent materials are used) from either face as the sidewalls of the cross-slits (both faces) fully close and block the view of the cavity/lumen connecting the two cross-slits just behind the closed sidewalls. Alternatively, the valve may be formed from multiple components, each including a set of one or more partial slits and a portion of a connecting hole, that may be applied together to provide a final valve.

In accordance with one embodiment, a valve is provided for a sheath, catheter, or other tubular device that includes a valve body comprising a first face, a second face opposite the first face and an axis extending between the first and second faces; a first slit extending from the first face towards the second face to a first intermediate location within the valve body; a second slit extending from the second face towards the first face to a second intermediate location within the valve body; and a bore extending along the axis between the first intermediate location and the second intermediate location.

In accordance with another embodiment, a valve is provided for a hub of a sheath, catheter, or other tubular device that includes a first valve portion formed from elastomeric material and comprising a first face, a first intermediate face opposite the first face and an axis extending between the first face and the first intermediate face, a first slit extending substantially parallel to the axis from the first face towards the first intermediate face to a first intermediate location within the first valve portion, and a first bore extending along the axis from the first intermediate location to the first intermediate face; and a second valve portion formed from elastomeric material and comprising a second face, a second intermediate face opposite the second face, a second slit extending substantially parallel to the axis from the second face towards the second intermediate face to a second intermediate location within the second valve portion, and a second bore extending along the axis from the second intermediate location to the second intermediate face, the first and second intermediate faces placed against one another such that first and second bores are aligned with one another to define a valve body.

In accordance with still another embodiment, a method is provided for making a valve for a sheath, catheter, or other tubular device that includes forming a resiliently flexible valve body comprising a first face, a second face opposite the first face and an axis extending between the first and second faces; forming a first slit extending substantially parallel to the axis from the first face towards the second face to a first intermediate location within the valve body; forming a second slit extending substantially parallel to the axis from the second face towards the first face to a second intermediate location within the valve body; and creating a bore extending along the axis from the first intermediate location to the second intermediate location.

In accordance with yet another embodiment, a method is provided for making a valve for a sheath, catheter, or other tubular device that includes forming a first valve portion comprising a first face, a first intermediate face opposite the first face and an axis extending between the first face and the first intermediate face, a first slit extending substantially parallel to the axis from the first face towards the first intermediate face to a first intermediate location within the first valve portion, and a first bore extending along the axis from the first intermediate location to the first intermediate face; forming a second valve portion comprising a second face, a second intermediate face opposite the second face, a second slit extending substantially parallel to the axis from the second face towards the second intermediate face to a second intermediate location within the second valve portion, and a second bore extending along the axis from the second intermediate location to the second intermediate face; and placing the first and second intermediate faces against one another such that first and second bores are aligned with one another to define a valve body.

Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.

