Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Implantable prosthesis – Hollow or tubular part or organ
Reexamination Certificate
1999-11-18
2001-08-14
Willse, David H. (Department: 3738)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Implantable prosthesis
Hollow or tubular part or organ
C623S001360, C623S001150, C623S001320
Reexamination Certificate
active
06273917
ABSTRACT:
FIELD OF THE ART
This invention relates to appliances for medical treatment and, more particularly, to an appliance collapsible for insertion into a human organ and capable of resilient restoration (which will be referred to as “the appliance to be implanted” in this specification and claims).
BACKGROUND ART
The artificial blood vessel is an example of the appliance to be implanted. At present, treatment of, for example, aortic aneurysm is conducted by implanting an artificial blood vessel. In particular, the portion of a blood vessel which has an aneurysm is removed by resection, and an artificial blood vessel is implanted in place of the resected portion and connected to the remaining blood vessel by suturing or the like.
The above-mentioned method of surgically implanting the artificial blood vessel for treatment of aortic aneurysm, however, is highly dangerous. Especially, an emergency operation for treatment of a ruptured aneurysm has a low life-saving rate, and an operation of dissecting aortic aneurysm is difficult to conduct and has a high death rate.
Therefore, in order to treat these diseases without a surgical operation, a method has been developed of introducing a catheter into an appliance such as an artificial blood vessel in a collapsed condition into a human organ such as a blood vessel, and transporting the appliance to a desired position such as an affected or constricted portion thereof, where the appliance is released so as to be expanded and implanted there.
The appliance to be implanted is so constructed that a pair of flexibly foldable and elastic end wire rings are arranged, each of the end wire rings is connected by a tubular cover which is made of a sheet of flexible and tensile material and an intermediate wire ring is arranged between both of the end wire rings and fixedly connected to the above-mentioned tubular cover by suturing or with adhesive.
As a method of collapsing the appliance to be implanted, the following method is adopted in which a plurality of hooking means for a pull string to be passed are formed at every other dividing points each of which equally divides the circumference of the front end wire ring into an even number, the front end wire ring is folded into a wavy shape with the dividing points which are provided with a hooking means for a pull string forming forwardly directed peaks and the dividing points which are not provided with a hooking means for a pull string forming the bottoms of forwardly directed valleys, each of the intermediate wire rings and the rear end wire ring is folded into a wavy shape having the same phase as that of the front end wire ring and the whole artificial blood vessel is inserted into a catheter.
However, since the conventional appliance has an arrangement in which the cover is fixedly attached to the front and rear end wire rings along the circumference thereof, the cover tries to follow the movement of the front and rear end wire rings and forms wrinkles near the front and rear end wire rings when the appliance is folded into a wavy shape. Then the wrinkles gather around the folded portion of the wire rings, thereby to be bulky. This may hinder the appliance from being folded into a small size having an appropriate wavy shape. In addition, if the cover is folded into a small size and making wrinkles, the cover may fail to restore smoothly to the original shape in a target position when released. This may hinder the function of the appliance to be implanted as it is intended to.
In order to solve the above problems there is an appliance to be implanted having an arrangement in which a front and rear end wire rings are fixed to a cover not along all of the outer circumference thereof but at several intermittent points so that the front and rear end wire rings can move freely at a certain degree relative to the cover. The appliance to be implanted of this arrangement, however, might cause blood leakage from an annular gap between the cover and the wire rings, if used inappropriately.
The object of the invention is to solve all of the above-mentioned problems.
DISCLOSURE OF THE INVENTION
The appliance to be implanted in accordance with the invention comprises a front end wire ring, a rear end wire ring arranged facing to the front end wire ring, a tubular cover which connects the front and rear end wire rings, and an intermediate wire ring arranged between the front and rear end wire rings, in which each of the wire rings is given flexibly foldable elasticity, and is characterized by having an arrangement in which each of the front and rear end wire rings and at least the intermediate wire rings arranged adjacent to the front and rear end wire rings is connected with the cover through a film member so that each of the wire rings can make a back and forth movement relative to the cover within a certain range and that an annular gap formed between each of the wire rings and the cover is liquid-tightly sealed.
In this specification it is a matter of course that a wire ring means a wire made of material having a high resilient restoring force such as Ti—Ni alloy, a wire whose circumference is covered with a protective material such as a braid member is also included.
The arrangement of the film member may concretely be represented by being bag-shaped in which whole of each wire rings is wrapped and one end of the film member is attached to the cover almost to surround the outer circumference thereof so as to allow each of the wire rings to make a back and forth movement by making use of transformation of the film member. The film member may also be annular and each of the wire rings is attached along almost all of an outer circumferential end of the film member and an inner circumferential end of the film member is attached along almost all of the outer circumference of the cover so as to allow each of the wire rings to make a back and forth movement by making use of transformation of the film. The film member may also have a long and narrow space therein along the direction of back and forth in which each of the wire rings is wrapped so as to allow each of the wire rings to make a back and forth movement inside the space relative to the cover.
Another preferred arrangement of the film member may be represented by that having a wavy shape undulating along the direction of the circumference thereof and to a direction almost corresponding with a direction to which the wire rings are folded.
To improve a condition of the folded intermediate wire ring it is preferable that the intermediate wire ring is wrapped in a mesh member, which is attached along almost all of an outer circumference of the cover.
To improve an implanting condition of the appliance to be implanted, it is preferable that an expanding element is filled in a space between the film member and each of the wire rings.
As a preferable arrangement of the expanding element, it may be represented that the expanding element is a fiber which surrounds an outer circumference of a wire which mainly constitutes the wire rings or a powder which is filled in a space between the film member and the wire rings.
A concrete embodiment of the expanding element may be represented by super absorbing processed polymer which expands itself when it absorbs liquid.
To improve restoration force or attachability of the appliance to be implanted, it is preferable that an auxiliary wire ring is attached to the cover at a position almost corresponding to a position each of the wire ring is attached to the cover.
In this case, as a preferable implanting method of the appliance to be implanted, it is represented that the circumference of the auxiliary wire ring is divided into four or an even number over four, hooking means are formed for a front pull string to be passed through at every other dividing point, the auxiliary wire ring is folded into a wavy shape with the dividing points at which a hooking means is provided forming forwardly directed peaks and the other dividing points forming the bottoms of forwardly directed valleys, each of the other wire rings is folde
Banner & Witcoff , Ltd.
Jackson Suzette J.
Willse David H.
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