MXPA99012025A - Apparatus and method to secure a stent on a gl - Google Patents

Abstract

The present invention relates to an apparatus for securing a stent having a longitudinal perforation in a balloon catheter, comprising: a) a first clamping portion and a second clamping portion, the first clamping portion provided with a first surface , a second surface and a third surface defines a first recess of holding portion, the second holding portion provided with a first surface, a second surface, a third surface, a fourth surface and a fifth surface defines a second portion recess of The first and second clamping portion cavities define a longitudinal channel of the stent narrowing element with a variable diameter, the first and second clamping portions adapted for movement in a first direction away from each other at a first direction and in a second direction towards each other to a second position, b) a first element or narrowing disposed within the longitudinal channel of the narrowing element of the stent, the first narrowing element provided with a contact surface of the first narrowing element, a contact surface of the second narrowing element, a first contact surface of the portion of clamping, and a contact surface of the narrowing sleeve of the stent, c) a second narrowing element disposed within the longitudinal channel of the narrowing of the stent, the second narrowing element provided with a first surface of constricting element, a surface of contact of the second narrowing element, a first contact surface of the holding portion, and a contact surface of the narrowing sleeve of the stent, d) a third narrowing element disposed within the longitudinal channel of the narrowing of the stent, the third element of narrowing provided with a contact surface of the first narrowing element, a contact surface of the second narrowing element, a second contact surface of the holding portion, and a contact surface of the narrowing sleeve of the stent; e) a fourth narrowing element arranged within the longitudinal channel of the narrowing of the stent, the fourth narrowing element provided with a contact surface of the first narrowing element, a contact surface of the second narrowing element, a second contact surface of the holding portion, and a surface of the narrowing sleeve of the stent, the narrowing elements adapted for movement in a first direction away from each other in a first direction and in a second direction towards each other to a second position, the contact surfaces of the narrowing sleeve of the stent define a narrowing cuff channel of the stent having a variable transverse diameter that is substantially circular when the plurality of narrowing elements is disposed in the second position, and f) a narrowing sleeve of the stent disposed in the longitudinal narrowing sleeve channel of the stent, the sleeve has a first end, a second end, an outer wall, and an internal wall defining a longitudinal orifice of narrowing of the stent therethrough having a substantially circular, selectively variable transverse diameter, the holding portions, the constricting elements, and the cuff adapted and arranged such that when the first fastening portion and the second fastening portion are in the second position, the narrowing sleeve contacting surfaces define a narrowing sleeve channel of the stent having a substantially circular transverse diameter and the longitudinal hole of narrowing The stent defines a longitudinal perforation having a substantially circular transverse diameter, and g) which further comprises: a first catheter protector disposed at the first end of the stent narrowing sleeve and a second catheter and catheter positioner disposed at the second end of the narrowing sleeve of the stent, the first catheter protector and the second catheter protector and positioner comprises an outer ring of compressible material and an inner ring of substantially non-compressible material, the inner ring of the second catheter shield and catheter positioner provided with an aperture sized small enough to prevent entry of the catheter and catheter. a stent not narrowed and sized large enough to allow entry of the catheter, the inner ring of the first catheter shield provided with an aperture dimensioned large enough to allow passage of a non-narrow stent

Description

APPARATUS AND METHOD TO SECURE A STENT ON A GLOBE FIELD OF THE INVENTION The present invention relates generally to intravascular stents for implantation within a living body. In particular, the present invention relates to intravascular stents that are expanded by means of an inflatable balloon catheter, and to a method and apparatus for mounting and securing a stent on a balloon catheter.

BACKGROUND OF THE INVENTION _ _ _ In the art, intravascular stents having a tight diameter for delivery through a blood vessel and an expanded diameter for applying a radially outwardly extending force to support the blood vessel are known. Self-expanding articulated stents are described, for example, in U.S. Patent No. 5,104,404, entitled "Articulated Stent" of Wolff. Balloon balloon expandable stents are commercially available under the registered trade name Palmaz-Schats Balloon-Expandable stents from Johnson & Johnson International Systems Co. In conventional stents mounting and securing procedures, usually the stent is first slid through the distal end of a balloon catheter, such that the expandable balloon is positioned within the longitudinal perforation of the stent. The stent is then squeezed or squeezed to mount or secure the stent and maintain its position with respect to the expandable balloon, as the balloon catheter is advanced toward the target area. This narrowing is often done using the fingers or a device similar to a clamp to tighten the stent. A drawback of this conventional mounting and securing means is that it frequently produces irregular deformation of the stent, which can cause trauma to the lumen being treated. Another drawback is that it may weaken a portion or portions of the stent which could result in the failure of the stent. Yet another drawback of conventional mounting and securing methods is that they can deform the stent in such a manner as to cause the stent to expand in the target area in a non-uniform manner, which could result in a portion of the lumen. is not properly supported. Yet another drawback of conventional mounting and securing methods is that irregular stent deformation can cause protrusions in the stent, which can cause trauma to the patient. Therefore, it would be highly desirable to have a method and apparatus that allows a stent to be secured over the expandable globe of a balloon catheter, without causing irregular deformation or weakening of the stent.

OBJECTIVES AND COMPENDIUM OF THE INVENTION It is an object of this invention to provide an apparatus for securing a stent on a balloon catheter, by substantially uniformly deforming the stent. It is another object of this invention to provide an apparatus for securing a stent on a balloon catheter, which reduces the likelihood that the stent will expand in a non-uniform manner. It is another object of this invention to provide a method for securing a stent on a balloon catheter, which reduces the likelihood that the stent will be weakened by the securing procedure. It is a further object of this invention to provide an apparatus for securing a stent on a balloon catheter, comprising: a) a first clamping portion, provided by a first clamping portion cavity, the first clamping portion cavity sized and adapted to receive a narrowing sleeve of the stent; b) a second clamping portion, provided with a second clamping portion cavity, the second clamping portion cavity sized and adapted to receive a narrowing sleeve of the stent, the first clamping portion cavity and the second portion cavity of clamping defining a longitudinal channel of the narrowing sleeve of the stent, having a variable transverse diameter, the first and second holding portions adapted for movement, in a first direction away from each other, to a first position, and in a second direction towards each other, to a second position, for selectively impart pressure to a narrowing sleeve of the stent placed in the longitudinal channel of the narrowing sleeve of the stent, the cavities of the clamping portion sized and adapted, such that the longitudinal channel of the narrowing sleeve of the stent has a transverse diameter substantially circular, when the first and second fastening portions are in the second position; c) a narrowing sleeve of the stent placed in the clamping sleeve channel, the sleeve having a first end, a second end, an external surface, and an internal surface, defining "a longitudinal" narrowing perforation of the stent to Through it, the longitudinal perforation of narrowing of the stent having a transverse diameter, selectively variable, substantially circular, and dimensioned and adapted to receive a balloon catheter with a stent mounted thereon, the narrowing sleeve of the stent further adapted to vary selectively and substantially uniformly the substantially circular transverse diameter of the longitudinal perforation of narrowing of the stent, in response to the pressure applied to the external surface of the stent narrowing sleeve, by means of the first clamping portion and the second portion of the stent. clamping, when the first clamping portion is moved and the second holding portion in the second direction. It is still another object of this invention to provide a method for securing an expandable stent having a longitudinal perforation on a balloon catheter, comprising the steps of: a) constructing an apparatus comprising: a first fastening portion provided with a first cavity of holding portion, the first holding portion cavity sized and adapted to receive a stenting sleeve of the stent; a second clamping portion, provided with a second clamping portion cavity, the second clamping portion cavity sized and adapted to receive a narrowing sleeve of the stent, the first clamping portion cavity and the second clamping portion cavity. defining a longitudinal channel of the narrowing sleeve of the stent, having a variable transverse diameter, the first and second holding portions adapted for movement, in a first direction away from each other, to a first position, and in a second direction a towards the other, to a second position, to selectively impart pressure to a narrowing sleeve of the stent placed in the longitudinal channel of the narrowing sleeve of the stent, the cavities of the clamping portion sized and adapted, such that the longitudinal channel of the narrowing sleeve of the stent has a substantially transverse diameter e circular, when the first and second fastening portions are in the second position; a narrowing sleeve of the stent having a first end, a second end, an external surface, and an internal surface, defining a longitudinal piercing of the stent therethrough, having a selectively variable, substantially circular transverse diameter, and dimensioned and adapted to receive a balloon catheter with a stent mounted thereon, the narrowing sleeve of the stent further adapted to selectively and substantially uniformly vary the substantially circular transverse diameter of the longitudinal narrowing perforation of the stent, in response to the pressure applied to the external surface of the stenting sleeve of the stent, by means of the first clamping portion and the second clamping portion, b) placing the stenting sleeve of the stent in the narrowing sleeve channel of the stent; c) placing the stent in the longitudinal narrowing perforation of the stent of the stent narrowing sleeve; d) placing the balloon catheter in the longitudinal perforation of the stent; and e) moving the first and second portions of narrowing of the stent from the first position to the second position, in order to apply pressure to the external surface of the narrowing sleeve of the stent, in an amount sufficient to decrease the substantially circular transverse diameter of the longitudinal drilling of the stent, in an amount sufficient for the inner surface of the stenting sleeve of the stent to impart sufficient pressure to the stent, to secure the stent to the balloon catheter. It is a further object of this invention to provide an apparatus for securing a stent on a balloon catheter, comprising: a) a first clamping portion, having a first clamping portion cavity, and a second clamping portion, having a second clamping portion cavity, the first and second clamping portion cavities defining a longitudinal channel of the stent narrowing member, with a variable transverse diameter, the first and second clamping portions adapted for movement, in a first direction remote from one another, to a first position, and in a second direction one towards the other, to a second position, b) a plurality of narrowing elements placed inside the longitudinal channel of the narrowing element of the stent, which defines a channel of narrowing sleeve of the stent, which has a variable transverse diameter, the plurality of narrowing elements adap for movement in a first direction away from each other, to a first position, and in a second direction, towards each other, to a second position; and c) a narrowing sleeve of the stent placed in the longitudinal narrowing channel of the stent, having a first end, a second end, an outer wall, and an inner wall, defining a longitudinal bore therethrough, having a substantially circular transverse diameter, the fastening portions, the constricting elements, and the sleeve adapted and positioned in such a way that when the first fastening portion, the second fastening portion, and the plurality of constricting elements are placed in the second position, the constricting elements define a longitudinal channel of the narrowing sleeve of the stent, having a substantially circular transverse diameter, and the longitudinal perforation of narrowing of the stent defines a longitudinal perforation having a substantially circular transverse diameter. It is still another object of this invention to provide an apparatus for securing a stent on a balloon catheter, comprising: a) a first clamping portion and a second clamping portion, the first clamping portion provided with a first surface, a second clamping portion. surface, and a third surface defining a first clamping portion cavity, the second clamping portion provided with a first surface, a second surface, a third surface, a fourth surface and a fifth surface defining a second portion cavity of clamping, the first and second clamping portion cavities defining a longitudinal channel of the narrowing element of the stent with a variable diameter, the first and second clamping portions adapted for movement in a first direction remote from each other, to a first position, and in a second direction one towards the other, to a second position; b) a first narrowing element positioned within the longitudinal channel of the stent narrowing element, the first narrowing element provided with a first contact surface of the narrowing element, a second contact surface of the narrowing element, a first surface of contact of the holding portion, and a contact surface of the narrowing sleeve of the stent; c) a second narrowing element placed inside the longitudinal narrowing channel of the stent, the second narrowing element provided with a first contact surface of the narrowing element, a second contact surface of the narrowing element, a first contact surface of the holding portion, and a contact surface of the narrowing sleeve of the stent; d) a third narrowing element positioned within the longitudinal narrowing channel of the stent, the third narrowing element provided with a first contact surface of the constricting element, a second contact surface of the constricting element, a second contact surface of the holding portion, and a contact surface of the narrowing sleeve of the stent; e) a fourth narrowing element positioned within the longitudinal narrowing channel of the stent, the fourth narrowing element provided with a first contact surface of the constricting element, a second contact surface of the constricting element, a second contact surface of the holding portion, and a contact surface of the narrowing sleeve of the stent, the constricting elements adapted for movement in a first direction remote from one another, to a first position, and in a second direction towards each other, to a second position, the contact surfaces of the narrowing sleeve of the stent defining a channel of the narrowing sleeve of the stent, having a variable transverse diameter, which is substantially circular when the plurality of narrowing elements are placed in the second position; and f) a narrowing sleeve of the stent placed in the longitudinal channel of the narrowing sleeve of the stent, the sleeve having a first end, a second end, an external wall, and an internal wall, defining a longitudinal bore therethrough, having a selectively variable, substantially circular transverse diameter, the clamping portions, the constricting elements, and the sleeve adapted and positioned in such a manner that when the first clamping portion and the second clamping portion are in the second position, the contacting surfaces of the constricting sleeve define a channel of the narrowing sleeve of the stent, which has a substantially circular transverse diameter, and the longitudinal perforation defines a longitudinal perforation having a substantially circular transverse diameter.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side view of a stent placed on a balloon catheter, before the stent has been secured to the balloon. Figure 2 is a side view of the stent of Figure 1, after the stent has been secured to the balloon, using conventional securing methods. Figure 3 is a transverse end view of an apparatus securing a stent, constructed in accordance with this invention, with the fastening portions placed in a first or unsecured position. Figure 4 is a transverse end view of an apparatus securing a stent, constructed in accordance with this invention, with the fastening portions placed in a second or secured position. Figure 5 is a cross-sectional side view of a stent narrowing sleeve, constructed in accordance with the invention. Figure 6 is an end view of the stent narrowing sleeve shown in Figure 5. Figure 7 is a cross-sectional side view of the stent narrowing sleeve of Figures 5 and 6, with the balloon catheter and the stent of Figure 1 placed inside it, before the stent is secured to the balloon. Figure 8 is an end view of Figure 7. Figure 9 shows the narrowing sleeve of the stent shown in Figures 5 and 6, positioned between the first and second fastening portions, with the first and second fastening portions. placed in a first or unsecured position. Figure 10 shows the narrowing sleeve of the stent shown in Figures 5 and 6, positioned between the first and second fastening portions, with the first and second fastening portions moved in a second or secured position. Figure 11 shows the stent of Figure 1 secured to the balloon catheter, after being secured in accordance with the invention. Figure 12 shows an alternative embodiment of the invention, having a first fastening portion and a second fastening portion placed in a first position. Figure 13 shows the fastening portions shown in Figure 12, with a plurality of constricting elements positioned between the fastening portions. Figure 14 shows the fastening portions and the constricting elements of Figure 13 placed in a second position. Figure 15 shows Figure 13 with a stent narrowing sleeve positioned between the constricting elements with the holding portions, and the constricting elements placed in a first or unsecured position. Figure 16 shows the embodiment shown in Figure 15 with the fastening portions and the constricting elements placed in a second or secured position. Figure 17 is a cross-sectional side view of an alternative embodiment of the invention using a catheter shield and a catheter shield and stent locator. Figure 18A is an end view of the second catheter shield and stent positioner shown in Figure 17. Figure 18B is an end view of the first catheter shield shown in Figure 17. Figure 19 is a view elongated detail of a portion of Figure 17.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows a conventional balloon catheter 1 and shows a catheter 2, a balloon 3, and a stent 4 mounted on the balloon 3, before the stent 4 is secured on the balloon 3. The Figure 2 shows the stent of Figure 1 after it has been secured to the balloon by means of conventional methods, for example, by means of tightening between the fingers or by means of shaking with a device similar to a conventional forceps. As shown in Figure 2, the ends of the stent protrude, and there is some irregular deformation of the stent between the two ends of the stent. Figure 3 shows a stent securing apparatus 5 constructed in accordance with the invention. Figure 3 shows a first fastening portion 6 having a first recess portion 7, and a second holding portion 8 having a second recess portion 9. The first clamping portion cavity 7 and the second clamping portion cavity 9 define a longitudinal channel 10 of stent narrowing sleeve with a selectively variable transverse diameter. Figure 3 shows the first clamping portion 6 and the second clamping portion 8 in a first or unsecured position, which provides a first separation DI between the first clamping portion 6 and the second clamping portion 8, which is suitable for inserting an uncompressed stent narrowing sleeve into the narrowing sleeve channel 10 of the stent. Figure 4 shows the first fastening portion 6 and the second fastening portion 8 of Figure 3 moved to a second or secured position, with a second clearance D2 between the first fastening portion 6 and the second fastening portion 8 which is less than that ID. In this way, when placed in the second or secured position, the first fastening portion 6 and the second fastening portion 8 are closer to each other than they are when placed in the first position and, as shown in Figures 3 and 4, the narrowing sleeve channel 10 has a smaller diameter. As also shown in Figure 4, when the first fastening portion 6 and the second fastening portion 8 are in the second position, the narrowing sleeve channel 10 has a substantially circular transverse diameter. The first fastening portion 6 and the second fastening portion 6 can be configured in a variety of ways well known to those skilled in the art, allowing selective movement of the first fastening portion 6 and the second fastening portion 8 of the fastening portion 6. the first position to the second position, that is, towards and away from each other. In the embodiment shown, a channel 11 aligns the first fastening portion 6 and the second fastening portion 8, and external pressure, eg, finger pressure, can be used to move the first fastening portion 6 and the second fastening portion 8 from the first position to the second position. In another embodiment, pneumatic pressure or an electric motor is used to move the fastening portions 6 and 8. In a particularly preferred embodiment, a manometer and a pressure regulator are used to control the amount of pressure applied. In still another embodiment, the first and second fastening portions 6 and 8 are mounted on a hinged device similar to a clamp. Figure 5 is a cross-sectional side view of a narrowing sleeve 12 of the stent, having an external surface 13 and an internal surface 14, defining a longitudinal perforation 15 of narrowing of the stent. Figure 6 is an end view of Figure 5. The narrowing perforation 15 of the stent has a substantially circular, selectively variable transverse diameter, which changes in response to the external pressure applied to the external surface 13 of the stent nipple 12 . The material comprising the narrowing sleeve 12 of the stent is selected from a material that varies substantially uniformly, and maintains the substantially circular transverse diameter of the longitudinal narrowing perforation of the stent, in response to the pressure applied to the stent. outer surface 13 of the stent nipple 12. In a preferred embodiment, polyurethane is used. Figure 7 shows the stent 4, balloon 3, and catheter 2 of Figure 1 positioned within the longitudinal narrowing perforation 15 of the stent of the narrowing sleeve 12 of the stent shown in Figure 5, before it narrow and secure the stent 4 to the balloon 3. Figure 8 is an end view of Figure 7. Figure 9 shows the narrowing sleeve 12 of the stent of Figures 5 and 6, placed in the narrowing sleeve channel 10 of the stent, between the first stent holding portion 6 and the second stent holding portion 8, of the stent securing apparatus 5. As shown in Figure 9, the first stent holding portion 6 and the second stent holding portion 8 are placed in a first position that provides adequate separation in the channel 10 of the stent narrowing sleeve, so that the narrowing sleeve 12 of the stent is easily inserted or removed from the channel 10 of the narrowing sleeve of the stent. The longitudinal perforation 15 has a substantially circular transverse diameter ID. Figure 10 differs from Figure 9 in that the first stent holding portion 6 and the second stent holding portion 8 have moved to a second position. The first clamping portion cavity 7 and the second clamping portion cavity 7 are sized and cooperatively adapted, such that when placed in the second position, the first and second clamping portions 6 and 8 define a channel 10 having a substantially circular transverse diameter. As shown in Figure 10, in response to the pressure applied by means of the first and second clamping portions 6 and 8 on the external wall 13 of the narrowing sleeve 12 of the stent, the narrowing sleeve 12 of the stent is compressed. This causes the diameter of the longitudinal narrowing perforation of the stent to substantially uniformly reduce to a substantially circular transverse diameter D2, which is smaller than the uncompressed diameter DI shown in Figure 9. In response to the External pressure applied to the external surface 13, the inner surface 14 of the stenting bore 15 applies a substantially uniform pressure to the stent 4, in a sufficient amount for the purpose of substantially uniformly constricting the stent 4, and securing it on balloon 3, with minimal irregular deformation of the stent 4, because the longitudinal perforation 15 maintains its substantially circular transverse diameter when the stent nipple 12 is compressed and the diameter of the narrowing perforation 15 of the stent is reduced. Figure 11 is a side view of the stent shown in Figure 1, after it has been secured according to the invention, and removed from the stent securing apparatus 5, and shows that the stent 4 has narrowed substantially uniformly, and secured on balloon 3 with minimal irregular deformation. Figures 12 to 16 show an alternative embodiment of the invention, which utilizes a plurality of constricting elements positioned between the clamping portions, to apply pressure to a stenting sleeve of the stent. Figure 12 shows a first fastening portion 16 and a second fastening portion 18. The first fastening portion 16 is provided with a first surface 19, a second surface 20, and a third surface 21 defining a first cavity 66 of fastening portion. The second fastening portion 18 is provided with a first surface 22, a second surface 23, a third surface 24, a fourth surface 25 and a fifth surface 26 that define a second cavity 67 of fastening portion. The surfaces 19, 20, 21, comprising the first clamping portion cavity 66, and the surfaces 22, 23, 24, 25, and 26 comprising the second clamping portion cavity 67, define a longitudinal channel 27 of the element. of narrowing of the stent with a transverse diameter, selectively variable. As shown in Figure 13, placed within the longitudinal channel 27 of the stent narrowing element, there is a first narrowing element 29, a second narrowing element 30, a third narrowing element 31 and a fourth narrowing element 32. The first constricting element 29 is provided with a first contact surface 33 of the constricting element., a second contact surface 35 of the constricting element, a first contact surface 34 of the clamping portion, and a contact surface 36 of the constriction sleeve of the stent. The second constricting element 30 comprises a first contact surface 37 of the constricting element, a second contact surface 39 of the constricting element, a first contact surface 38 of the clamping portion, and a contact surface 40 of the clamping sleeve. narrowing of the stent. The third constricting element 31 is provided with a first contact surface 41 of the constricting element, a second contact surface 43 of the constricting element, a second contact surface 42 of the clamping portion, and a contact surface 44 of the stent narrowing sleeve. The fourth element 32 is provided with a first contact surface 45 of the constricting element, a second contact surface 47 of the constricting element, a second contact surface 46 of the clamping portion, and a contact surface 48 of the clamping sleeve. narrowing of the stent. The contact surfaces 36, 40, 44, and 48 of the narrowing sleeve of the stent define a narrowing sleeve channel 10 of the stent, which has a selectively variable transverse diameter. Figure 13 shows the first clamping portion 16, the second clamping portion 18, and the constricting elements 29, 30, 31, and 32 placed in a first or unsecured position, which provides a transverse diameter of the channel 101 of the narrowing sleeve of the stent, which is suitable for inserting a narrowing sleeve 12 of the uncompressed stent, into the channel 101 of the narrowing sleeve of the stent. As the first clamping portion 16 and the second clamping portion 18 move to the second position, the surface 19 strikes against the surface 34, the surface 21 strikes against the surface 38, the surface 23 strikes against the surface 46 and the surface 25 strikes against the surface 42, moving the narrowing elements 29, 30, 31, and 32 to a second or secured position. Figure 14 shows the first clamping portion 16, the second clamping portion 18, and the constricting elements 29, 30, 31, and 32 placed in a second position, the surfaces 36, 40, 44, and 48 of the clamping sleeve. narrowing of the stent by defining a channel 10 'of the constricting sleeve having a substantially circular transverse diameter D2, which is smaller than the diameter Di shown in Figure 13. The first clamping portion 16 and the second clamping portion 18 they may be configured in a variety of ways well known to those skilled in the art, allowing selective movement of the first clamping portion 16 and the second clamping portion 18 in a first direction away from each other, to a first position , and in a second direction one towards the other, to a second position. Figures 15 and 16 show a narrowing sleeve 12 of the stent (previously described) positioned in the longitudinal channel 10 'of the narrowing sleeve of the stent. (The stent and the balloon catheter have been omitted for clarity). As shown in Figure 15, when the first clamping portion 16 and the second clamping portion 18, and the constricting elements 29, 30, 31, and 32 are positioned in the first position, some portions of the surfaces 36, 40, 44, and 48 of contact of the constricting element may or may not be in contact with any portion of the external surface 13 of the stent nipple 12, because when the first clamping portion 16, the second clamping portion 18, and the narrowing elements 29, 30, 31, and 32 are in the first position, the surfaces 36, 40, 44, and 48 do not define a narrowing sleeve channel 10 of the stent, which has a substantially circular transverse diameter. In this way, when the first and second fastening portions and the constricting elements are in the first or unsecured position, there may be open spaces 68 between the external surface 13 of the narrowing sleeve 12 of the stent and the surfaces 36, 40, 44, and 48 of contact of the constricting element. As shown in Figure 16, however, when the first fastening portion 16, the second fastening portion 18, and the constricting elements 29, 30, 31, and 32 are placed in the second or secured position, substantially all the contact surfaces 36, 40, 44, and 48 of the constricting element are in contact with the external surface 13 of the constricting sleeve 12, because the surfaces 36, 40, 44, and 48 are dimensioned and adapted to define a channel 10. 'of the narrowing sleeve of the stent, defining a substantially circular transverse diameter, when the first clamping portion 16, the second clamping portion 18, and the constricting elements 29, 30, 31, and 32 are placed in the second position . As shown in Figure 15, when the first fastening portion 16, the second fastening portion 18, and the constricting elements 29, 30, 31, and 32 are positioned in the first or unsecured position, the perforation 15 narrowing of the stent has a substantially circular transverse diameter of ID. As shown in Figure 16, when the first clamping portion 16, the second clamping portion 18, and the constricting elements 29, 30, 31, and 32 are positioned in the second or secured position, the tapering hole 15 of the stent has a substantially circular transverse diameter D2, which is smaller than DI. Because the narrowing perforation 15 of the stent maintains its substantially circular transverse diameter, when the first portion 16 of.

When the second clamping portion 18 is clamped, and the constricting elements 29, 30, 31, and 32 are placed in the second position, the internal surface 14 of the narrowing sleeve 12 of the stent applies substantially uniform pressure to the stent 4 so that is mounted narrowly over the balloon catheter 1 placed inside the longitudinal perforation 15 of narrowing of the stent, and to substantially substantially uniformly tighten and secure the stent 4 to the balloon catheter on which it is mounted, with minimal irregular deformation of the Stent 4. Figures 17 to 19 show an alternative embodiment of the invention, in which a first catheter protector 60 and a second stent catheter and stent 61 are used, to protect the catheter shaft, and also to limit the movement of the stent along the longitudinal axis of the catheter, resulting in more precise placement on the catheter. Figure 17 is a cross-sectional side view and shows a balloon catheter 1, a stent 4, a guidewire 65, a first catheter shield 60 and a second stent catheter and stent 61. Figure 18A is an end view of the second catheter shield and stent positioner 61 shown in Figure 17, and Figure 18B is an end view of the first stent shield 60 shown in Figure 17. As shown in Figure 18A, the second catheter guard and positioner 61 is circular in cross section and comprises an outer ring 62 of compressible material, and an inner ring 63 of substantially non-compressible material. The inner ring 63 is provided with an inner ring opening 64 having a substantially circular transverse diameter. As shown in Figure 18B, the first catheter shield 60 is circular in cross section and comprises an outer ring 62 'of compressible material, and an internal ring 63' of substantially non-compressible material. The inner ring 63 'is provided with an inner ring opening 64' having a substantially circular transverse diameter. In a preferred embodiment, the substantially compressible material is polyurethane, and the substantially non-compressible material is metal. Figure 19 is an enlarged view of the second catheter shield and stent positioner 61, and the first catheter shield 60 of Figure 17. As shown, the inner ring opening 64 of the substantially non-compressible inner ring 63 of the second shield of stent catheter and positioner 61 is sized large enough to allow catheter 2 to enter into internal ring opening 64, and is dimensioned small enough to prevent stent 4 from entering ring opening 64 internal. In this manner, the inner ring opening 64 is dimensioned small enough to prevent entry of the non-constricted stent 4, and is sized large enough to allow entry of the balloon portion 3 of the catheter 2 into the opening 64 of internal ring. Because the inner ring opening 64 is substantially non-compressible, it protects the portions of the catheter 2 and guidewire 65 placed inside the inner ring opening 64 of the inner ring 63 during the securing procedure. The internal substantially non-compressible ring 63 also acts as a stop to positively position the stent 4 on the catheter 2. In an especially preferred embodiment, the balloon portion of the catheter has an external diameter of about 0.9 to about 1.2 millimeters, the opening 64 of the inner ring of the second catheter protector and stent positioner 61 has a diameter of about 1.4 millimeters, the non-expanded and unstretched stent has an external diameter of about 1.7 to about 1.75 millimeters, and the narrowed stent has a diameter of about 1.0 to approximately 1.1 millimeters. As shown in Figures 17, 18A, 18B, and 19, the first catheter shield 60 has an inner ring opening 64 'that is larger than the inner ring opening 64 of the second catheter shield and stent positioning 61. The internal ring opening 64 'is sized large enough to allow passage of an untwisted stent through the inner ring opening 64' and into the longitudinal stent-narrowing perforation of the narrowing sleeve of the stent. stent In a particularly preferred embodiment, a diameter of about 1.9 millimeters to about 2.0 millimeters is used. In operation, the non-constricted stent is advanced through the inner ring opening 64 'of the first catheter shield 60, and into the longitudinal narrowing bore of the stent, until the stent is in contact with the second stent guard. catheter and stent positioner 61. because the second stent catheter guard and stent 61 has an inner ring opening 64 that is smaller than the diameter of a non-stent stent, and larger than the catheter diameter, the catheter stent and stent positioner 61 it serves both to position the stent and to protect the distal end of the catheter. The catheter is then inserted into the longitudinal perforation of the stent, and the stent is narrowed over the balloon portion of the catheter. After the stent has been tapered over the balloon portion of the catheter, the catheter is withdrawn with the stent narrowed thereon, by pulling the catheter through the inner ring opening 64 'of the first catheter shield 60.

Claims (14)

1. CLAIMS 1. An apparatus for securing a stent on a balloon catheter, comprising: a) a first clamping portion, provided with a first clamping portion cavity, the first clamping portion cavity dimensioned and adapted to receive a clamping sleeve of the stent; b) a second fastening portion, provided a second clamping portion cavity, the second portion cavity of. clamping dimensioned and adapted to receive a narrowing sleeve of the stent, the first clamping portion cavity and the second clamping portion cavity defining a longitudinal channel of the narrowing sleeve of the stent, having a variable transverse diameter, the first and second holding portions adapted for movement, in a first direction spaced apart from each other, to a first position, and in a second direction towards each other, to a second position, to selectively impart pressure to a narrowing sleeve of the stent placed in said longitudinal channel of the narrowing sleeve of the stent, the cavities of the clamping portion sized and adapted, such that the longitudinal channel of the narrowing sleeve of the stent has a substantially circular transverse diameter, when the first and second holding portions are in the second position; c) a narrowing sleeve of the stent placed in the clamping sleeve channel, the sleeve having a first end, a second end, an external surface, and an internal surface, defining a longitudinal perforation of the stent narrowing therethrough , the longitudinal perforation of narrowing of the stent having a transverse diameter, selectively variable, substantially circular, and sized and adapted to receive a balloon catheter with a stent mounted thereon, the narrowing sleeve of the stent further adapted to selectively and substantially vary uniformly the substantially circular transverse diameter of the longitudinal perforation of narrowing of the stent, in response to the pressure applied to the external surface of the stent shrink sleeve, by means of the first clamping portion and the second clamping portion, when move the first clamping portion and the second a holding portion in said second direction.
2. 2. The apparatus of claim 1, wherein the narrowing sleeve of the stent comprises polyurethane. The apparatus of claim 2, wherein the longitudinal narrowing perforation of the stent has a cross-sectional diameter of approximately 1.9 millimeters when said first and said second fastening portions are positioned in the first position. 4. The apparatus of claim 1, characterized in that it also comprises: a first catheter guard placed on the first end of the stent constriction sleeve, and a second stent catheter and stent holder, positioned at the second end of the stent sleeve. narrowing of the stent, the first catheter guard and the second catheter guard and stent positioner each comprising an outer ring of compressible material, and an inner ring of substantially non-compressible material, the inner ring of the second catheter guard and the positioner of stent provided with an aperture dimensioned small enough to prevent entry of the untwisted stent, and sized large enough to allow entry of said balloon catheter, the inner ring of the first catheter shield provided with an aperture sufficiently dimensioned large enough to allow the stent to pass narrowed The apparatus of claim 4, wherein the outer ring comprises polyurethane, and the inner ring comprises metal. 6. A method for securing an expandable stent having a longitudinal perforation on a balloon catheter, comprising the steps of: a) constructing an apparatus comprising: a first clamping portion provided with a first clamping portion cavity, first clamping portion cavity dimensioned and adapted to receive a narrowing sleeve of the stent; a second clamping portion, provided with a second clamping portion cavity, the second clamping portion cavity sized and adapted to receive a narrowing sleeve of the stent, the first clamping portion cavity and the second clamping portion cavity defining a longitudinal channel of the narrowing sleeve of the stent, having a variable transverse diameter, the first and second holding portions adapted for movement, in a first direction spaced apart from one another, to a first position, and in a second direction one towards the other, to a second position, to selectively impart pressure to a narrowing sleeve of the stent placed in the longitudinal channel of the narrowing sleeve of the stent, the cavities of the clamping portion dimensioned and adapted, such that the longitudinal channel of the stent stent narrowing sleeve have a substantially transverse diameter e circular, when the first and second fastening portions are in the second position; a narrowing sleeve of the stent having a first end, a second end, an external surface, and an internal surface, defining a longitudinal piercing of the stent therethrough, having a selectively variable, substantially circular transverse diameter, and dimensioned and adapted to receive a balloon catheter with a stent mounted thereon, the narrowing sleeve of the stent further adapted to selectively and substantially uniformly vary the substantially circular transverse diameter of the longitudinal narrowing perforation of the stent, in response to the pressure applied to the external surface of the stenting sleeve of the stent, by means of the first clamping portion and the second clamping portion, b) placing the stenting sleeve of the stent in the narrowing sleeve channel of the stent; c) placing the stent in the longitudinal narrowing perforation of the stent of the stent narrowing sleeve; d) placing the balloon catheter in the longitudinal perforation of the stent; and e) moving said first and said second portions of narrowing of the stent from the first position to the second position, in order to apply pressure to the external surface of the narrowing sleeve of the stent, in an amount sufficient to decrease the substantially circular transverse diameter of the longitudinal piercing of the stent, in an amount sufficient for the internal surface of the narrowing sleeve of the stent to impart sufficient pressure to the stent, to secure the stent to the balloon catheter. The method of claim 6, characterized in that it also comprises the additional step, before step b), of placing a first catheter guard on the first end of the narrowing sleeve of the stent, and a second catheter shield and positioner of stent at the second end of the narrowing sleeve. stent, the first catheter guard and the second catheter guard and positioner comprising, each comprising an outer ring of compressible material, and an inner ring of substantially non-compressible material, the inner ring of the second catheter guard and stent positioner provided with an aperture dimensioned small enough to prevent entry of an untwisted stent, and sized large enough to allow entry of said balloon catheter, the inner ring of the first catheter shield provided with a sufficiently large sized aperture as to allow the passage of the stent not narrowed. 8. An apparatus for securing a stent having a longitudinal perforation on a balloon catheter, comprising: a) a first clamping portion, having a first clamping portion cavity, and a second clamping portion., having a second holding portion cavity, the first and second holding portion cavities defining a longitudinal channel of the narrowing element of the stent, with a selectively variable transverse diameter, the first and second holding portions adapted for movement, in a first direction away from each other, to a first position, and in a second direction towards each other, to a second position, b) a plurality of narrowing elements placed inside the longitudinal channel of the stent narrowing element , which defines a narrowing sleeve channel of the stent, having a variable transverse diameter, the plurality of narrowing elements adapted for movement in a first direction remote from one another, to a first position, and in a second direction, towards the others, to a second position; and c) a narrowing sleeve of the stent placed in the longitudinal narrowing channel of the stent, having a first end, a second end, an outer wall, and an inner wall, defining a longitudinal bore therethrough, having a substantially circular, selectively variable transverse diameter, the clamping portions, the constricting elements, and the sleeve adapted and positioned in such a way that when the first clamping portion, the second clamping portion, and the plurality of clamping elements are placed in the second position, the constricting elements define a longitudinal channel of the narrowing sleeve of the stent, which has a substantially circular transverse diameter, and the longitudinal narrowing perforation of the stent defines a longitudinal perforation having a. substantially circular transverse diameter. 9. An apparatus for securing a stent having a longitudinal perforation, on a balloon catheter, comprising: a) a first fastening portion and a second fastening portion, said first fastening portion provided with a first surface, a second fastening portion surface, and a third surface defining a first clamping portion cavity, the second clamping portion provided with a first surface, a second surface, a third surface, a fourth surface and a fifth surface defining a second portion cavity of clamping, the first and the second clamping portion cavities defining a longitudinal groove of the narrowing element of the stent with a variable diameter, the first and second clamping portions adapted for movement in a first direction remote from each other, to a first position, and in a second direction one towards the other, to a second position; b) a first narrowing element positioned within the longitudinal channel of the stent narrowing element, the first narrowing element provided with a first contact surface of the narrowing element, a second contact surface of the narrowing element, a first surface of contact of the holding portion, and a contact surface of the narrowing sleeve of the stent; c) a second narrowing element placed inside the longitudinal narrowing channel of the stent, the second narrowing element provided with a first contact surface of the narrowing element, a second contact surface of the narrowing element, a first contact surface of the holding portion, and a contact surface of the narrowing sleeve of the stent; d) a third narrowing element positioned within the longitudinal narrowing channel of the stent, said third narrowing element provided with a first contact surface of the constricting element, a second contact surface of the constriction elongation, a second contact surface of the holding portion, and a contact surface of the narrowing sleeve of the stent; e) a fourth narrowing element positioned within the longitudinal narrowing channel of the stent, the fourth narrowing element provided with a first contact surface of the constricting element, a second contact surface of the constricting element, a second contact surface of the holding portion, and a contact surface of the narrowing sleeve of the stent, the constricting elements adapted for movement in a first direction remote from one another, to a first position, and in a second direction towards each other, to a second position, the contact surfaces of the narrowing sleeve of the stent defining a channel of the narrowing sleeve of the stent, having a variable transverse diameter, which is substantially circular when said plurality of narrowing elements are placed in the second position; and f) a narrowing sleeve of the stent placed in the longitudinal channel of the narrowing sleeve of the stent, the sleeve having a first end, a second end, an outer wall, and an internal wall, which define a longitudinal bore therethrough, having a selectively variable, substantially circular transverse diameter, the clamping portions, the constricting elements, and the sleeve adapted and positioned in such a manner that when the first clamping portion and the second clamping portion are in the second position, the contacting surfaces of the constricting sleeve define a channel of the narrowing sleeve of the stent, which has a substantially circular transverse diameter, and the longitudinal perforation defines a longitudinal perforation having a substantially circular transverse diameter. 10. The apparatus of claim 9, characterized in that it further comprises: a first catheter guard positioned on the first end of the stent-narrowing sleeve, and a second stent-catheter and stent-holder, positioned at the second end of the stent sleeve. narrowing of the stent, the first catheter guard and the second catheter guard and positioner comprising an outer ring of compressible material, and an inner ring of substantially non-compressible material, the inner ring of said second catheter guard and stent positioner provided with an aperture dimensioned small enough to prevent entry of the untwisted stent, and dimensioned large enough to allow entry of the catheter, the inner ring of the first catheter shield provided with an aperture sized large enough to allow passage of the stent not narrowed. 11. The apparatus of claims 1, 2, 3, 4, 5, 8, 9, or 10, characterized by also comprises an element for moving the first clamping portion and the second clamping portion of said first position to said second position. 12. The apparatus of claim 11, wherein the element for movement is a pneumatic device. The apparatus of claim 11, wherein the element for movement is an electric motor. The apparatus of claim 11, wherein the element for movement is a hinged device resembling a clamp.