Patent Application
20140031923
1. Field
The present disclosure relates to systems for delivering a prosthesis to a desired location in the body of a patient and methods for delivering and implanting a prosthesis. More particularly, the present disclosure relates to prosthetic valve introducer systems for deploying a heart valve prosthesis within a body lumen and to methods of delivering such a prosthesis to a desired location in the body.
2. Background
Currently, replacement of a deficient cardiac valve is often performed by placing the patient under extracorporeal circulation, temporarily stopping the heart, opening the thorax (e.g., by a sternotomy), surgically opening the heart, excising the deficient valve, and then implanting a prosthetic valve in its place. This procedure generally requires prolonged patient hospitalization, as well as extensive and often painful recovery.
Recently, minimally invasive approaches have been developed to facilitate catheter-based implantation of valve prostheses in the beating heart, intending to obviate the need for the classic sternotomy and cardiopulmonary bypass. For example, U.S. Pat. No. 8,016,877 to Seguin et al. illustrates a technique and a device for replacing a deficient heart valve by percutaneous route. An expandable prosthetic valve can be compressed about a catheter, inserted inside a body lumen, such as the femoral artery, and delivered to a desired location in the heart. Additionally, U.S. Pat. No. 7,914,569 to Nguyen et al. discloses advancing a catheter containing a prosthesis in a retrograde manner through the femoral artery and into the descending aorta, over the aortic arch, through the ascending aorta and inside the defective aortic valve. This procedure can be assisted by fluoroscopic guidance. Once the position of the catheter containing the prosthesis is confirmed, a sheath containing the prosthesis can be moved proximally, allowing the valve prosthesis to self-expand.
However, in certain instances it may still be necessary to use the classic sternotomy technique. It would be desirable to avoid cardiopulmonary bypass during this procedure while still obtaining accurate positioning of the prosthetic valve.
Other techniques for delivering prosthetic heart valves via a catheter include transapical and trans-aortic approaches for aortic valve replacement, typically involving the use of an introducer port, i.e., a large-bore overtube, of a trocar. A crimped, framed valve prosthesis reversibly coupled to a delivery catheter can be transcatheterally advanced toward the native valve, where it can either be deployed using a balloon catheter, or, alternatively, using a self-expandable system.
With regard to the structure of the heart valve prosthesis itself, U.S. Pat. No. 7,914,569 to Nguyen et al. describes an example prosthesis for percutaneous transluminal delivery, and is incorporated by reference herein in its entirety. The heart valve prosthesis can have a self-expanding multi-level frame that supports a valve body with a skirt and plurality of leaflets. The frame can be contracted during percutaneous transluminal delivery and expanded to an hourglass shape upon deployment within the native heart valve.
The present disclosure describes valve introducer systems for implanting a heart valve prosthesis through a trans-aortic pathway. By directly accessing the aorta, it is possible to accurately implant a prosthetic valve without the need for cardiopulmonary bypass, although the disclosed valve introducer systems can also be used with cardiopulmonary bypass. Furthermore, the valve introducer systems disclosed herein allow for one-handed deployment of the prosthetic valve, providing a quick, single-shot and accurate deployment.
In certain embodiments, the valve introducer can include a delivery shaft with a distal tip and a tubular member to house a prosthetic valve, and a deployment element to push the prosthetic valve out of the distal tip of the delivery shaft. In certain embodiments, the valve introducer can include a handle with a deployment element, a deployment element housing and at least one finger gripping element connected to the deployment element housing.
In order to deliver the valve prosthesis, the delivery shaft can be inserted into a body lumen and advanced to a desired deployment location. In certain embodiments, the prosthetic valve can be deployed by pushing the deployment element in a distal direction, thereby pushing the prosthetic valve out the distal tip of the delivery shaft.
The accompanying figures, which are incorporated herein, form part of the specification and illustrate embodiments of valve introducer systems and methods of delivering a prosthesis to a desired location in a body of a patient. Together with the description, the figures further serve to explain the principles of and allow for the making and using of the valve introducer systems and methods described herein. These figures are intended to be illustrative, not limiting. Although the disclosure is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the disclosure to these particular embodiments. In the drawings, like reference numbers indicate identical or functionally similar elements.
While the disclosure refers to illustrative embodiments for particular applications, it should be understood that the disclosure is not limited thereto. Modifications can be made to the embodiments described herein without departing from the spirit and scope of the present disclosure. Those skilled in the art with access to this disclosure will recognize additional modifications, applications, and embodiments within the scope of this disclosure and additional fields in which the disclosed examples could be applied. Therefore, the following detailed description is not meant to be limiting. Further, it is understood that the systems and methods described below can be implemented in many different embodiments of hardware. Any actual hardware described is not meant to be limiting. The operation and behavior of the systems and methods presented are described with the understanding that modifications and variations of the embodiments are possible given the level of detail presented.
References to “one embodiment,” “an embodiment,” “in certain embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
Deployment element 104 can be used to deploy a prosthetic valve loaded into delivery device 100. Generally, deployment element 104 can be designed to deploy the prosthetic valve in a single shot, that is, by deploying the prosthetic valve from delivery device 100 in one smooth motion. The user can control the speed of deployment by the rate at which the user activates deployment element 104. In certain instances, the user may wish to reposition the prosthetic valve after beginning to deploy the prosthetic valve. The user can accomplish this by moving the entire delivery device 100 in a distal or proximal direction.
In certain embodiments, such as the one shown in
In certain embodiments, deployment element 104 and deployment element housing 108 can be generally cylindrical in shape. Deployment element 104 can be configured to slidably engage with deployment element housing 108, such as by a channel or groove, as illustrated in
In certain embodiments, deployment element 104 can include a feature to assist in pushing or pulling deployment element 104. For example,
In certain embodiments, one or more finger grips 106 can be located on, or connected to, deployment element housing 108. Finger grips 106 can include an interior surface formed by a hole or ring element to allow insertion of a finger, an exterior surface for gripping, or both. The gripping surfaces can be curved to provide comfort and tactile feel. Generally, the index finger and middle finger can utilize finger grips 106 to steady delivery device 100 while the thumb can be used to push or pull deployment element 104 during deployment of the prosthetic valve. By grasping finger grips 106 and pushing or pulling deployment element 104 with the thumb, the user can deploy the prosthetic valve.
Handle 102 can also include access port 116. Access port 116 can be used, for example, to extract air from the system, introduce fluid into the system, or insert additional surgical tools through the system and into the body lumen.
Delivery shaft 110 can be inserted into a body lumen to deliver a prosthetic valve. In certain embodiments, delivery shaft 110 can be generally cylindrical in shape, with a smooth exterior surface. This can help prevent damage to the interior of the body lumen. Capsule 112 and distal tip 114 can be located at the distal end of delivery shaft 110. Capsule 112 can house a prosthetic valve. Generally, a collapsible and self-expanding prosthetic valve, such as the one in U.S. Pat. No. 7,914,569 to Nguyen et al., can be loaded into capsule 112 prior to the surgical procedure.
The interior of delivery shaft 110, capsule 112 and distal tip 114 can all be coated with a biocompatible lubricant, which can decrease friction with the prosthetic valve and allow a smooth exit during deployment. In certain embodiments, distal tip 114, can be an atraumatic tip. It can be flexible to prevent damage to the interior of the body lumen, and expandable to allow it to expand from its generally tapered configuration in embodiments where the prosthetic valve is pushed out of delivery shaft 110 during deployment. In certain embodiments, distal tip 114 can be biased to a tapered configuration so that it returns to the tapered configuration after the prosthetic valve is deployed out of distal tip 114. In certain embodiments, distal tip 114 can be radiopaque to assist in locating distal tip 114 with medical imaging during the implantation procedure. In certain embodiments, distal tip 114 can be used to puncture the exterior surface of a body lumen to provide access to the interior of the body lumen, similar to a syringe.
In certain embodiments, such as the one shown in
Methods of delivering a prosthetic valve are also provided. Reference to the Figures may be used by way of example. Prior to surgery, the desired valve implantation location should be determined. This can be done with the assistance of medical imaging, such as a CT scan. For prosthetic aortic valve implantation via a trans-aortic route, the implantation location is generally located within aortic sinus 504 such that the distal part of prosthetic valve 302 engages the leaflets of the natural aortic valve, and the proximal part of prosthetic valve 302 engages the inner wall of the ascending aorta. Alternative implantation sites can be used, and the optimal implantation site can be determined by a physician for each individual patient.
Generally, a patient's chest can be opened such that aorta 402 is exposed. This can be accomplished, for example, by a mini-sternotomy or a thoracotomy. Delivery shaft 110 can be inserted into aorta 402 at an insertion point. The aorta, as defined herein, can include the exterior surface and lumen of the descending aorta, aortic arch, ascending aorta and aortic sinus. In certain embodiments, distal tip 114 of delivery shaft 110 can be used to puncture the surface of aorta 402 at the insertion point. In certain embodiments, an incision can be made and hemostatic valve 502 can be secured at the insertion point to provide an access point to aorta 402.
A radially collapsed prosthetic valve 302 can be loaded into delivery shaft 110 or capsule 112. In certain embodiments, prosthetic valve 302 can be pre-loaded in delivery device 100 or 300. Delivery shaft 110 can then be inserted directly into aorta 402, or through hemostatic valve 502 into aorta 402.
After delivery shaft 110 is inserted into aorta 402, delivery shaft 110 can be advanced distally until distal tip 114 reaches the desired deployment location. In certain embodiments, medical imaging can be used to locate distal tip 114 of delivery shaft 110 within aorta 402 prior to deployment of prosthetic valve 302. Delivery shaft 110 can be moved in a proximal or distal direction to adjust the deployment location of prosthetic valve 302 so that prosthetic valve 302 can be properly implanted within aortic sinus 504.
Once in the proper location, in certain embodiments, prosthetic valve 302 can be deployed by pushing deployment element 104 in a distal direction, thereby pushing prosthetic valve 302 out of distal tip 114 of delivery shaft 110. In certain embodiments, deployment element 104 can be pushed to advance distal tip 114, or pulled to retract capsule 112, to deploy the prosthetic valve. In other embodiments, deployment element 104 can be configured such then when deployment element 104 is pushed, capsule 112 is retracted.
Generally, prosthetic valve 302 can be a self-expanding prosthetic valve, such that it will expand to a pre-fabricated size and shape within aortic sinus 504 after being deployed. In certain embodiments, a balloon can be included under the prosthetic valve, and inflated to expand and deploy the prosthetic valve.
After deployment of prosthetic valve 302, delivery device 300 can be removed from aorta 402. If hemostatic valve 502 is used, it can be detached from aorta 402, and sutures can be used to close the insertion point.
The foregoing description has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the precise embodiments disclosed. Other modifications and variations may be possible in light of the above teachings. The embodiments and examples were chosen and described in order to best explain the principles of the embodiments and their practical application, and to thereby enable others skilled in the art to best utilize the various embodiments with modifications as are suited to the particular use contemplated. By applying knowledge within the skill of the art, others can readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein.
