Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Arterial prosthesis – Stent in combination with graft
Reexamination Certificate
2001-06-04
2003-02-04
Isabella, David J. (Department: 3734)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Arterial prosthesis
Stent in combination with graft
C623S001440
Reexamination Certificate
active
06514282
ABSTRACT:
FIELD OF THE ART
This invention relates to a method of collapsing an appliance to be implanted which belongs to a field of medical devices (wherein the appliance collapsible for insertion into a human organ and capable of resilient restoration will be referred to as “an appliance to be implanted” in this specification and claims) and the appliance to be implanted.
BACKGROUND ART
With a recent progress of medical techniques, a technique enabling transvascular use of a variety of appliances such as artificial blood vessels without ventrotomy has reached a clinical stage. Specific examples of such a technique include a method of transferring and fixing an artificial blood vessel using a catheter which has been invented by the inventor of present claimed invention and disclosed in the paper (for example, PCT/JP96/01347 which has been published with International Publication No. WO96/36387). This method includes; inserting a catheter into a human body through an inguinal artery to position a front end thereof near an affected portion in which an aneurysm or the like is present, inserting a tubular artificial blood vessel provided with collapsible/restorable elasticity into the catheter in a collapsed condition, transporting the artificial blood vessel to a predetermined location near the affected portion by the use of a transporting device or a hauling device, and releasing the artificial blood vessel from the catheter at the location, thereby to position the artificial blood vessel in an affected blood vessel having the aneurysm.
In the above-described document, the appliance to be implanted 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 end wire ring and the rear end wire ring, and a plurality of intermediate wire rings spaced apart from each other between the front end wire ring and the rear end wire ring in which the circumference of the front end wire ring is equally divided into four or an even number over four segments with dividing points between the segments and hooking portions are formed for a front pull string to be passed through at every other dividing point between the segments, the front end wire ring is folded into a wavy shape with the dividing points where the hooking portion is provided forming a forwardly directed peak and the other dividing points forming a bottom of a forwardly directed valley and the intermediate wire rings and the rear end wire ring are folded into a wavy shape having the same phase as that of the front end wire ring.
With the method of collapsing the artificial blood vessel, a number of the hooking portions for a front pull string equals to a number of peaks when collapsed. In the artificial blood vessel of the above arrangement if a number of the hooking portions is set to be small, for example, two, pulling force is difficult to be transferred uniformly to the artificial blood vessel when the artificial blood vessel is released from the catheter, which makes the artificial blood vessel tilt easily. As a result, it becomes difficult to release the artificial blood vessel with the front end wire ring opening at right angles to an axis of the artificial blood vessel. In addition, the artificial blood vessel might not be able to be restored into an appropriate original shape after released from the catheter due to a possible habit of the wire rings because a pulling force is concentrated on the peaks of the wire rings while the artificial blood vessel is transported in the catheter.
In order to solve the above problems, it can be conceived that the number of hooking portions is increased. However, in this arrangement the number of the peaks also increases inevitably, resulting in being bulky when collapsed. As a result, it is difficult to transport thus arranged artificial blood vessel stably without causing bulky when collapsed. In addition, it is impossible to get rid of stress concentration fully because the artificial blood vessel is hauled at a portion of the peak.
DISCLOURE OF THE INVENTION
In order to solve the above problems, in collapsing an appliance to be implanted comprising 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 end wire ring and the rear end wire ring, and an intermediate wire ring arranged between the front end wire ring and the rear end wire ring, in which each of the wire rings is given flexibly foldable elasticity, the present claimed invention is characterized by that circumference of a front end portion of the appliance to be implanted is equally divided into four or an even number over four segments with dividing points between the segments, a front hooking portion for hauling the appliance to be implanted is formed at midpoints between each adjacent two of the dividing points, the front end portion is collapsed into a wavy shape with every other dividing point forming a forwardly directed peak and other dividing point forming a bottom of a forwardly directed valley and the intermediate wire ring and the rear end wire ring are collapsed into a wavy shape having generally the same phase as that of the front end portion.
In order not to prevent the appliance to be implanted from being collapsed by the intermediate wire ring it is preferable that the appliance to be implanted is collapsed in a condition that the intermediate wire ring is fixed to the tubular cover at positions which generally correspond to the positions where the front hooking portions are provided.
In order to keep the collapsed condition for sure it is preferable that the appliance to be implanted is kept in a collapsed condition by a retaining means and the collapsed appliance to be implanted is restored into an original shape by releasing the retaining means at a target position.
In order to make it possible to release the appliance to be implanted from the collapsed condition in a remote place without fail it is preferable that the retaining means comprises a string which is wound around the collapsed appliance to be implanted and which has a loop at one portion thereof and a retaining rod which passes through the loop of the string, the appliance to be implanted is kept in the collapsed condition by passing the retaining rod through the loop of the string and the collapsed condition by means of the string is released by drawing the retaining rod out of the loop.
In case a rear hooking portion for hauling the appliance to be implanted is provided at a position which has generally the same phase as that of a position where a front hooking portion is provided on a rear end portion of the appliance to be implanted, it is preferable that the appliance to be implanted is collapsed so that the rear hooking portion locates at midpoints between the forwardly directed peaks and the bottoms of forwardly directed valleys when the rear end portion is collapsed to have generally the same phase as that of the front end portion.
In case a rear hooking portion for hauling the appliance to be implanted is provided at every other position which has generally the same phase as that of the dividing points on a rear end portion of the appliance to be implanted, it is preferable that the appliance to be implanted is collapsed so that the rear hooking portion locates at the bottoms of the forwardly directed valleys of the rear end portion when the rear end portion is collapsed to have generally the same phase as that of the front end portion.
In order to collapse the appliance to be implanted into a small size with ease it is effective if the front and rear end wire rings are connected with the tubular cover through a film member so that an annular gap at least formed between each of the front and rear end wire rings and the tubular cover is liquid-tightly sealed and the appliance to be implanted is collapsed with each of the front and rear end wire rings making a back and forth movement relative to the tubular cover within a certain range.
In order to secure an appropriate function of transport
Banner & Witcoff , Ltd.
Isabella David J.
Phan Hieu
LandOfFree
Method of folding transplanting instrument and transplanting... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of folding transplanting instrument and transplanting..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of folding transplanting instrument and transplanting... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3134906