Medical device anchor and delivery system

Abstract

A method and apparatus for anchoring a medical implant device after the device has been brought to rest at a desired position within a blood vessel or other body passageway. An anchor delivery system is provided which houses one or more uniquely configured expandable anchors which are connected to the medical implant device. The anchors remain housed in a non expanded configuration until after the medical implant device has come to rest in a desired position within the body, and then the anchors are positively propelled through a body wall from a first side to a second side where each anchor expands outwardly from an anchor shaft. In one configuration, the anchors are each formed in the shape of a compressible closed loop which extends outwardly from an anchor shaft and loops back to cross over and extend beyond the anchor shaft. To positively propel the anchors, a drive shaft for the anchor shafts extends back to a triggering unit which, when activated, causes the drive shaft to drive the anchor shafts in a direction which results in propulsion of the anchors through the body wall.

Description

[0001] This application is a Continuation-in-Part application of Ser. No. 10 / 705,226 filed Nov. 12, 2003.BACKGROUND OF THE INVENTION [0002] Recent advances in medical technology have resulted in the development of a variety of medical devices for permanent or temporary implantation in the human body. Effective positioning of such devices can prove to be a very difficult task, and maintaining an implanted device in a desired position for an extended period of time is often more difficult. This is particularly true if the implanted device is to remain only temporarily and is designed to facilitate subsequent removal. [0003] A number of medical implant devices are designed to collapse for insertion within a catheter or other delivery unit and to expand to a predetermined shape when ejected after delivery. Many of these self expanding devices rely primarily upon the contact between the device and the wall of a body vessel or passageway to maintain the device in position after the delive...

AI Technical Summary

Benefits of technology

"The present invention provides a novel and improved method for positioning and anchoring a medical implant device in a body. The method involves using an anchor delivery system that houses one or more uniquely configured anchors which are connected to the implant device. The anchors remain housed until after the implant device has come to rest in a desired position within a body, and then the anchors are positively propelled through a body wall from a first side to a second side where each anchor expands from a single shaft configuration. The anchor delivery system facilitates the withdrawal and re-insersion of the anchors without requiring the implant device to be compressed and / or removed. The invention also provides an improved anchor design that allows for the expansion of the anchor shaft in response to forces applied thereto, and a unique filter design that allows for the ejection of the anchor through a side opening in the filter leg. Overall, the invention provides a more efficient and effective method for positioning and anchoring medical implant devices in a body."

Problems solved by technology

Effective positioning of such devices can prove to be a very difficult task, and maintaining an implanted device in a desired position for an extended period of time is often more difficult.

Unfortunately, changes in the dimensions of the body vessel or passageway or variations in the flow of blood or other fluids there through can cause the medical implant to migrate and change position.

Otherwise, effective performance of such therapeutic devices will not be achieved.

It is often very difficult to move such a device into position with the desired orientation, and once this is achieved, it is critical that no further motion occur.

This may be acceptable for a permanent implant, but rigid hooks are not a viable option if the medical implant device is to be removed after several weeks or months.

Anchoring hooks, although effective in many instances, are subject to a number of disadvantages which can make it difficult to properly position and maintain the position of a medical implant device.

In prior devices, the anchoring hooks are engaged due to the expansion of the device into contact with the wall of a body vessel or passageway, and if the device moves from a desired position during expansion and contact with the wall occurs, the device cannot be easily repositioned.

The anchoring function of the hooks is not separable from the expansion of the device.

In cases where the operation of the hooks is tied to the expansion of a medical implant device, there can be instances where one or more of the hooks fails to properly engage the wall of a body vessel or passageway causing the device to become off center.

Sometimes movement of the device longitudinally will engage the errant hooks, but this movement can also alter the position of the device.

Also, the configuration of a hook which curves in a single direction from a shaft to a pointed end can prove to be a disadvantage.

However, there are conditions which can result in a backflow of blood in a blood vessel, and pressure on the device and the anchoring hooks resulting from such backflow can cause the hooks to back out and disengage from the vessel, thus changing the orientation of the device within the blood vessel and causing deleterious changes in the performance of the implant.

Finally, even if the hooks of an implant device are properly engaged with a vessel wall, there are conditions which result in the subsequent outward expansion of the vessel wall to an extent where the hooks tend to become disengaged.

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