MXPA97006013A - Small tube with variable characteristics parapootize the support and method for manufacturing my - Google Patents

Abstract

The present invention relates to a small tube or expandable stent, characterized in that it comprises: a) a plurality of interconnected flexible cells defining a small tube having a proximal end and a distal end and a longitudinal axis, the cells arranged or distributed in a plurality of interconnected flexible rows, positioned along the longitudinal axis of the small tube with a distant row positioned at the distal end of the small tube and a neighboring row positioned at the proximal end of the small tube, each of the flexible cells comprises a first element, a second element, a third element and a fourth element

Description

SMALL TUBE WITH VARIABLE CHARACTERISTICS TO OPTIMIZE THE SUPPORT AND METHOD OF MANUFACTURE OF THE SAME BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates generally to small tubes for implantation in a living body. In particular, the present invention relates to small intraluminal tubes suitable especially for implantation in a variety of lumens or cavities having variable characteristics, such as a variable curvature, lateral branches, variable diameters, variable wall elasticity or "effects of end "of any of the lumens or cavities, as found, for example, in small entrances to the cavities, or in the small tube when the parameters can change at their ends.

DESCRIPTION OF PREVIOUS TECHNIQUE It is already known to use a small tube to expand and support the different bodily conduits, such as the blood vessels, by expanding a tube-like structure within the vessel that R «f.25297 requires support against sinking or closing. The U.S. Patent No. 5,449,373 shows a small tube preferably used for the vascular implant as part of a balloon angioplasty procedure. The small tube of U.S. Pat. No. 5,449,373 can be supplied through, or implanted in, a curved vessel or duct. A disadvantage of such conventional small tubes is that they may have deficiencies due to "end effects" where the ends of the small tube tend to "widen" during insertion or after expansion, or have a reduced radial force at the end. . Yet another disadvantage of conventional small tubes is that they do not have different characteristics, (for example, flexibility and stiffness), to accommodate any changing characteristics of the lumen section or cavity that requires different characteristics of the small tube.

BRIEF DESCRIPTION AND OBJECTS OF THE INVENTION The present invention provides various embodiments of a small intraluminal tube which includes varied or different mechanical properties along the axial length of the small tube to improve the effects of the ends of the small tube, or to accommodate the varying characteristics of the vessel or conduit. As a result, the various embodiments of the present invention allow for variable properties such as flexibility or radial support between the axial regions of the small tube. These varied properties can be effected in a number of different ways, including reducing or increasing the thickness or width of the elements of one or more of the sections relative to the other sections and / or increasing or reducing the axial length of the sections. one or more of the sections and / or change the shape and size of the cells and / or change the properties of the material (e.g., strength or strength, elasticity, etc.) of the material in a section relative to the other sections. The various embodiments of the small tubes of the present invention can be adapted to provide more flexibility at the ends to allow the small tube to accommodate the curvature of a container in which the small tube is implanted. The degree of flexibility and the distance from the end of the small tube to which additional flexibility is imparted can be varied as required by specific applications. This flexibility at the ends reduces the likelihood of a potential trauma point being created in the vessel or conduit by the tip of the small tube that applies pressure to the outer side of the curve if the small tube is not flexible enough to along its longitudinal axis. In one embodiment of the present invention, the flexibility of the ends of the small tube is increased by reducing the size of the material used in a section or sections at the ends of the small tube. In another embodiment the flexibility of the ends of the small tube is increased by changing the dimensions of a section or sections at the ends of the small tube. In yet another embodiment of the invention, the flexibility of the ends of the flexible tube is increased by changing both the dimensions and the caliber of the material used in a section or sections at the ends of the small tube. The various embodiments of the small tubes of the present invention can also be adapted to ensure increased radial strength at the ends. Radial resistance is the resistance of a section of the small tube, in an expanded state, to radial contraction. The increase in radial resistance of a small tube at the ends is particularly advantageous for the small tubes that support the small entrances of the cavities. Because lesions in an ostium tend to be more calcified or hardened, and therefore require greater support, the section of the small tube that supports the ostium must be relatively strong. There is also the case where a small tube with uniform characteristics has a reduced radial force at the end due to the "end effect", whereby the last row does not provide support on one side. In one embodiment of the present invention, the resistance of the small tube at the end that supports, for example, the ostium, is increased by reducing the length of some sections at the end of the small tube. The various embodiments of the small tube of the present invention also reduce the likelihood of "widening" at the end of the small tube while the small tube is being fed into a vessel or conduit. During insertion of the catheter delivery system into a curved container, the delivery system, including the small tube secured thereon, is bent along the curvature of the vessel or conduit. This bending of the small tube can cause a "widening" of the leading edge of the small tube. This widening could cause the small tube to be trapped on the surface of the vessel or duct which could lead to trauma to the vessel or duct, which would inhibit further insertion and proper placement in the target or target area, and could cause that the plaque ruptures, which could embolize and cover the vessel or duct. In one embodiment of the present invention, the broadening is minimized by making the end section of the small tube stronger by reducing its length, and by making the sections adjacent to the small tube more flexible by reducing their widths, thus decreasing the bending strength of these sections. . The resistance to bending is the resistance of a section of the small tube to the axial fold. As a result, the end of the small tube remains slightly curled or curved on the balloon, and the bending or bending moment is received by the deformation of the more flexible sections. During expansion, the reduced resistance to bending allows the end of the small tube to curve and better adjust to the curvature of the vessel or conduit, whereby the pressure of the tip of the small tube on the inner wall of the vessel is reduced. or conduit that is treated. It is an object of this invention to provide a small tube which does not have sharp points or protrusions at its ends that concentrate pressure on the vessel wall during the expansion of the small tube into a curved portion of a vessel or conduit. It is another object of this invention to provide a small tube having a radial force at its remote end that is larger than the radial force in the portion of the small tube proximate the remote end.

It is still another object of this invention to provide an expandable small tube, comprising: a plurality of interconnected flexible cells defining a small tube having a proximal end and a remote end and a longitudinal axis, the cells are arranged or distributed in a plurality of interconnected flexible rows connected along the longitudinal axis of the small tube with a remote row placed at the far end of the small tube and a neighboring row positioned at the proximal end of the small tube, wherein the cells placed in the row away from the tube small are adapted to exert a radial force larger than and are additionally adapted to be more flexible than the cells placed in the rows placed between the remote row and the proximal end of the small tube. It is still another object of this invention to provide an expandable small tube, comprising: a plurality of interconnected flexible cells defining a small tube having a proximal end and a remote end and a longitudinal axis, the cells are arranged or distributed in a plurality of interconnected flexible rows, placed along the longitudinal axis of the small tube with a remote row placed at the far end of the small tube and a neighboring row placed at the proximal end of the small tube, where the cells in the row away from the tube small and the cells placed in the next row of the small tube are adapted to exert a larger radial force and are further adapted to be more flexible than the cells placed in the rows arranged between the remote row and the next row. It is another object of this invention to provide an expandable small tube, comprising: a) a plurality of interconnected flexible cells defining a small tube having a proximal end and a remote end and a longitudinal axis, the cells distributed in a plurality of rows flexible interconnected placed along the longitudinal axis of the small tube with a remote row placed at the far end of the small tube and a next row placed at the proximal end of the small tube, each of the flexible cells comprises a first element, a second element, a third element, and a fourth element; b) a first loop or C-shaped loop placed between the first element and the third element; c) a second loop or loop placed between the second element and the fourth element; d) a first flexible connector placed between the first element and the second element; and e) a second flexible connector placed between the third element and the fourth element, wherein the cells of the remote row are provided with first and third elements that are shorter than the second and fourth elements in the remote row, and where the The remote row is provided with first and second flexible connectors that are more flexible than the flexible connectors in the cells in the other rows of the small tube. It is still another object of this invention to provide an expandable small tube, comprising: a) a plurality of interconnected flexible cells defining a small longitudinal tube having a proximal end and a remote end and a longitudinal axis, the cells arranged or distributed in a plurality of interconnected flexible rows arranged along the longitudinal axis of the small tube with a remote row placed at the far end of the small tube and a next row positioned at the proximal end of the small tube, each of the flexible cells comprises a first element, a second element, a third element, and a fourth element; b) a first loop or C-shaped loop placed between the first element and the third element; c) a second loop or C-shaped loop, placed between the second element and the fourth element; d) a first flexible connector placed between the first element and the second element; and e) a second flexible connector placed between the third element and the fourth element, wherein the cells of the remote row are provided with first and third elements that are shorter than the second and fourth elements in the remote row, and where the The remote row, and the row next to the remote row, are provided with first and second flexible connectors that are more flexible than the flexible connectors in the other rows of the small tube. It is a further aspect of this invention to provide an expandable small tube comprising: a) a plurality of flexible cells defining a small tube having a proximal end and a remote end and a longitudinal axis, the cells arranged or distributed in a plurality of flexible rows along the longitudinal axis with a remote row placed at the far end of the small tube and a next row placed at the proximal end of the small tube, each of the flexible cells comprises a first element, a second element, a third element, and a fourth element; b) a first loop or C-shaped loop placed between the first element and the third element; c) a second loop or C-shaped loop placed between the second element and the fourth element; d) a first flexible connector placed between the first element and the second element; and e) a second flexible connector placed between the third element and the fourth element, wherein the cells of the remote row are provided with first and third elements that are shorter than the second and fourth elements in the remote row, and where the cells of the next row are provided with second and fourth elements that are shorter than the first and third elements in the next row, and where the row is distant, and the row next to the row away, and the row next and the remote row with respect to the next row are provided with first and second flexible connectors that are more flexible than the flexible connectors in the other rows of the small tube. It is still another object of this invention to provide an expandable small tube, comprising: a plurality of flexible cells defining a small tube having a proximal end and a remote end, the small tube provided with means for imparting a radial force at its end remote that is larger than the radial force in the portion of the small tube near the far end. It is still a further object of this invention to provide an expandable small tube, comprising: a plurality of flexible cells defining a small tube having a proximal end and a remote end, the small tube provided with means for imparting a radial force in its proximal and remote ends that is greater than the radial force of that portion of the small tube placed between the proximal and remote ends. It is another object of this invention to provide an expandable small tube for treating a lumen or cavity having a unique feature along a portion thereof, comprising: a plurality of interconnected flexible cells, the cells arranged or distributed in a plurality of interconnected flexible rows defining a small tube having a proximal end and a remote end and a longitudinal axis, wherein at least one of the rows is adapted to accommodate the unique characteristic of that portion of the lumen or cavity in contact with the row or adapted rows. It is still another object of this invention to provide a small flexible tube, unique, with a one-piece or single-body construction, which is capable of supporting a lumen or cavity along the entire length of the body. small tube and in which the portions of the small tube are adapted or modified to have characteristics, for example, flexural strength or radial resistance, which are different than the characteristics or peculiarities in the rest of the small tube throughout its longitudinal axis or around its circumference. The change in characteristics of the small tube will either accommodate non-uniform areas in the treated lumen or cavity or may create different environmental conditions in different areas in the lumen or cavity. The disuniformity in a treated vessel or conduit can be of many different types such as an ostium, change in diameter, change of curvature, a non-continuous cross-section such as rectangular or square, or disuniformity in the surface nature, etc. To accommodate or adapt to such disuniformity, the portions of the small tube can be adapted to provide changing conditions of dimension, flexibility, rigidity, cell size, the shape of the cells, and the response to pressure as dictated by the specific applications. Specific applications can dictate, for example, a higher, desired radial force at one end while the other portions of the small tube provide a substantially continuous support to the wall of the container with the gaps or voids in the small tube sized with a size small enough to reduce the likelihood of tissue prolapse. Other applications can dictate a desired degree of stiffness at the center to reduce the likelihood of breakage and impart the desired degree of softness at the end to allow for the best fit with the anatomy of the target or target area. Other applications may dictate that one or more of the rows be provided with cells that are sized larger than the cells in the remaining rows of the small tube to provide access to a lateral branch in the lumen or cavity, for example, to introduce a second small tube through one of the larger cells to allow the construction of a small bifurcated tube inside the lumen. Still other applications may require that one or more of the rows be provided with cells which are adapted or modified so that during the expansion of the small tube, the portion of the small tube defined by the row or adapted or modified rows has a diameter that it is either larger or smaller than the remaining portions of the small tube to accommodate lumens or cavities with non-uniform diameters. One or more rows of cells can also be adapted or modified to have a variable radial force, or a variable longitudinal flexibility, or to correct a change in properties at the end of the small tube.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an illustration of the basic configuration of a small tube embodiment of the present invention, shown in an unexpanded state; Figure 2 shows an illustration of the configuration of the small tube of Figure 1, in a partially expanded state; Figure 3 is a side view showing a conventional small tube and a small tube manufactured according to an embodiment of the invention; Figure 4 shows the small tubes of Figure 3 crimped or bent over a balloon catheter and flexed prior to expansion; Figure 5 shows the small tubes of Figure 4 after they have been expanded in a curve; Figure 6 shows the small tubes of Figure 3 partially expanded over a substantially straight balloon catheter; Figure 7 shows an alternative embodiment of the invention provided with a shortened C-shaped loop or loop, and in which two rows of cells are provided with looser-gauge loops or U-shaped loops; Figure 8 shows the small tube of Figure 7 partially expanded over a substantially straight balloon catheter; Figure 9 shows the small tube of Figure 7 after it has been expanded over a curved catheter so that it could be inserted around an elbow or bend in a vessel or duct; Figure 10 shows an alternative embodiment of a small tube constructed in accordance with the invention; and Figure 11 shows the "S" or "Z" shaped loops or curls constructed in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows the general configuration of a mode of a small tube 1 manufactured in accordance with the present invention. The small tube 1 can be made of biocompatible materials such as 316L stainless steel, gold, tantalum, nitinol or other materials well known to those skilled in the art as suitable for this purpose. The dimensions and the size of the material used can be varied when specific applications require it. The small tubes of the present invention can generally be constructed in a manner according to the small tube described in the Application U.S. Patent Serial No. 08 / 457,354, filed June 1, 1995, the description of which is incorporated herein by reference. Figure 1 is a side view of the far end 2 of the small tube 1 of the present invention, showing the general configuration of the small tube. As shown in Figures 1 and 2, the configuration can be described as a plurality of cells 3 and 3d. Each cell 3 is provided with a first element 4, a second element 5, a third element 6, and a fourth element 7. A first C-shaped loop or loop 10 is placed between the first element 4 and the third element 6 and a second C-shaped loop or loop 11 is placed between the second element 5 and the fourth element 7. In each of the cells 3, the first element 4, the second element 5, the third element 6, and the fourth element 7 are substantially equal. Accordingly, the first loop or C-shaped loop 10 is shifted to a distance DI and a second loop or C-shaped loop 11 is placed at a distance D2 from the center of cell 3. In a preferred embodiment, DI is substantially equal to D2. A first flexible connector 8 is placed between the first element 4 and the second element 5 and a second flexible connector 9 is placed between the third element 6 and the fourth element 7. The flexible connectors 8 and 9 can be made in a variety of ways , for example, an "S" or "Z" shape as shown in Figure 11. In a preferred embodiment, a "U" shape is used, as shown in Figures 1 to 10. Figure 1 shows the configuration of the small tube 1 in an unexpanded state, ie, that state in which the small tube 1 is first inserted into a particular vessel or conduit in which a balloon angioplasty procedure is to be effected, but before the inflation of the ball. Figure 2 shows the configuration of the small tube 1 in a partially expanded state, that is, that state after the balloon has been expanded, for example, by a balloon, and the state in which the small tube 1 remains in the vessel or conduit which it supports. The plurality of interconnected cells 3 and 3 'form a plurality of interconnected rows 25, 26, 27, and 28 of the cells placed along the longitudinal axis of the small tube 1. Figures 1 and 2 show a remote row 25 placed at the far end 2, a row 26 adjacent to and adjacent to row 25, a row 27 adjacent to and adjacent to row 26, and a row 28 adjacent to and adjacent to row 27. It will be appreciated that the number of rows, and the number of cells per row, and the shape of each cell, can be varied when specific applications require it.

As shown in Figures 1 and 2, the cells 3 'in the remote row 25 differ from the cells 3 in the rows 26, 27, and 28. The first element 4' and the third element 6 'of the cells 3' in the row 25 are shorter than the first element 4 and the third element 6 of the cells 3 in the rows 26, 27 and 28. In the cell 3 ', the first element 4' is substantially equal to the third element 6d however , the first element 4 'and the third element 6' are shorter than the second element 5 'and the fourth element 7'. The shorter elements 4 'and 6' lead to a first C-shaped loop 10 'which is not placed as far from the center of the cell 3' as the second C-shaped loop '11'. , the first C-shaped loop 10 'can be thought of as being "shorter" than the second C-shaped loop or loop 11'. As shown in Figure 2, the first loop or loop 10 ' C-shaped is placed at a distance DI 'that is smaller than the distance D2' that the second loop or curl 11 'C-shaped is placed from the center of the cell 3'. In a particularly preferred embodiment, DI 'is approximately 15% less than D2'. Figures 1 and 2 also show that the remote row 25 of the small tube 1 is provided with a first loop or curl 8 'U-shaped and a second loop or curl 9' U-shaped which is more flexible than the first loop or curl 8 with U-shape and a second loop or curl 9 with U-shape of cells 3 in rows 26, 27, and 28 of small tube 1. This greater flexibility in loops or curls 8 'and 9' U-shaped can be made in a variety of ways, for example, by using a different material, treating the material for example, using the annealing of the stainless steel to impart selective hardness grades to the different portions of the small tube. Alternatively, if, for example, NiTi (Nitinol) is used, selected portions of the small tube can be thermomechanically treated selectively so that portions of the small tube, e.g., U-shaped elements, will remain in the martensitic phase while other portions of the small tube will be transformed into the austenitic phase in this section to give different properties. A greater flexibility can also be achieved by changing the shape of the "U", for example to a "Z" or an "S" (as shown in Figure 11), or by reducing the amount of material used to make the U-shaped loops or curls 8 'and 9'. In the embodiment shown in FIGS. 1 and 2, the U-shaped loops or curls 8 'and 9' of the row 25 are provided with the same thickness of the material as the U-shaped loops or curls 8 and 9 of the cells 3 in the rows 26, 27, and 28, however, the U-shaped loops or curls 8 'and 9' are not as wide. 1 and 2, the U-shaped loops or curls 8 'and 9' have a width W1 that is smaller than the width W2 of the U-shaped loops or curls 8 and 9 in the cells 3 of the rows 26 , 27, and 28. In a preferred embodiment, W1 is approximately 50% narrower than W2, In a particularly preferred embodiment, the W1 is approximately 40% narrower than W2, Figure 3 is a comparison. n side by side of two sections of the small tube and shows a conventional small tube 12, compared to the small tube 1, shown in Figures 1 and 2. Figure 4 shows the small tubes 1 and 12 shown in Figure 3 as the they appear when they are curled or curled on a balloon and bend as they could bend during insertion around a curve of a vessel or duct. As shown in Figure 4, the small tube 12 widens at its leading edge 13 in contrast to the small tube 1 which does not. Figure 5 shows the small tubes of figure 4 after the small tubes have been expanded in a curve. The tip of the conventional small tube 12 produces a protrusion or sharp point 13 which could cause local pressure and possible trauma to the vessel wall or duct. By contrast, the small tube 1 constructed in accordance with the invention bends smoothly at its end 2 without forming a protrusion or sharp point because of the deformation of the U-shaped loops or curls 8 'and 9' in the remote row. makes the 2 end softer. Figure 6 shows the small tubes 1 and 12 of Figure 3 in a partial expansion (before it reaches the maximum pressure) placed on a substantially straight catheter. As shown, although the two small tubes 1 and 12 are subjected to the same force outward, the end 2 of the small tube 1 is less expanded than the end 13 of the conventional small tube 12, demonstrating the increased radial force of the end 2 of the small tube 1 constructed in accordance with the invention. At the total pressure, the spokes of the small tubes 1 and 12 will be equal, however, the end 2 of the small tube 1 will have a greater radial resistance to the sinking than the end 13 of the small tube 12. Figure 7 shows a modality alternative of the invention. As shown in Figure 7, the cells 3 'in the row 25 are provided with a first element 4' and a third element 6 'which are shorter than the second element 5' and the fourth element 7 '. The cells 3 'in the row 25 are provided with a first loop or curl 8' U-shaped and a second loop or curl 9 'U-shaped, which are thinner than the loops or curls 8 and 9 in the shape of U in cells 3 in rows 27 and 28. Cells 3"in row 26 are provided with the first loops or loops 8" U-shaped and the second loops or loops 9"U-shaped that are narrower that the loops or curls 8 and 9 U-shaped in cells 3 in rows 27 and 28. Figure 8 shows the small tube 20 of figure 7 during the partial expansion of the small tube, showing the reduced expansion of the row 25 in the partial expansion due to the higher radial force of the end 2 of the small tube which results from the construction with the shorter C-shaped loops or curls 10 'in row 25, the construction with the loops or curls 8 'and 9' with U-shape, narrower, that is to say, more flexible, in row 25, * '8"and 9" in row 26. Figure 9 shows the small tube 20 of figures 7 and 8 after it has been expanded in a curved vessel or duct and shows the elbows or bends of the U-shaped loops or curls 8 'and 9' in the row 25 and 8"and 9" in row 26 which allow the end portion 2 of the small tube 20 to conform more easily to the curve of the vessel or conduit, creating smooth ends without sharp points or projections projecting towards the wall of the vessel or conduit. Changes can be made on only one side or on both sides of the small tube when specific applications require it. Additionally, different combinations of the embodiments of the invention can be mixed, such as the use of looser U-shaped loops or curls, longer U-shaped loops or loops or loops or curls differently, for example, with "Z" or "S" shape. An example of how this can be achieved is shown in Figure 10. Figure 10 shows how the small tube shown in Figure 7 can be modified, if additional flexibility is desired. As shown in Figure 10, the remote row 25, and the next row 29 of the small tube 30 are provided with first and second U-shaped loops or curls that are more flexible than the U-shaped loops or curls in the U-shaped loops. other rows of the small tube placed between the remote and neighboring rows 25 and 29. In the embodiment of the invention shown in Figure 10, the remote row 25 is provided with shortened elements 4 'and 6' and loops or curls 8 'and 9'. 'U-shaped, more flexible, as previously described, and the next row 29 is provided with second and fourth shortened elements 5' 'and 7' 'and loops or curls 8' '' and 9 '' 'in the shape of Or more flexible.

This arrangement imparts a larger radial resistance and a greater flexibility to both ends of the small tube. Even if greater flexibility is desired at the ends of the small tube, the small tube shown in Figure 10 can be modified by replacing the U-shaped loops or curls in the rows 26 and 28 with looser loops or curls. Accordingly, the far row, the row next to the far row, the next row, and the row away from the next row are provided with loops or U-shaped loops that are more flexible than loops or curls with a shape of U in the cells in the remaining rows of the small tube. The present invention contemplates a number of different variations and changes in different properties to achieve other non-uniform characteristics such as, but not limited to, cell size, cell shape, radio opacity, etc., on the preferred embodiments described above. The specified changes are only taken as an example for the application of the general concept, which is the basis for the present invention that small tubes with variable mechanical properties between the sections along the small tube can correct the undesirable effects at points such as the ends of the small tube and are provided for a better fit or adaptation to a vessel or conduit with changing properties along its axis. It is to be understood that the foregoing description is only of a preferred embodiment, and that the scope of the invention is to be measured by the claims described below.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers, Having described the invention as above, property is claimed as contained in the following

Claims (50)

1. An expandable small tube, characterized in that it comprises: a plurality of interconnected flexible cells defining a small tube having a proximal end and a remote end and a longitudinal axis, the cells arranged or distributed in a plurality of interconnected flexible rows, placed at the length of the longitudinal axis of the small tube with a remote row placed at the far end of the small tube and a next row placed at the proximal end of the small tube, where the cells placed in the row away from the small tube are adapted to exert a force radially larger and are adapted to be more flexible than the cells placed in the rows placed between the remote row and the proximal end of the small tube.

2. The small tube according to claim 1, characterized in that the cells in the remote row are of different size than the cells placed in the rows placed between the remote row and the proximal end of the small tube.

3. The small tube according to claim 1, characterized in that the cells in the remote row are of a thinner caliber than the caliber of the material used in the cells placed between the remote row and the proximal end of the small tube.

4. The small tube according to claim 1, characterized in that the cells in the remote row are made of a material that is more flexible than the material used in the cells placed between the remote row and the proximal end of the small tube.

5. An expandable small tube, characterized in that it comprises: a plurality of interconnected flexible cells defining a small tube having a proximal end and a remote end and a longitudinal axis, the cells arranged or distributed in a plurality of flexible rows interconnected along the longitudinal axis of the small tube with a remote row placed at the far end of the small tube and a neighboring row placed at the near end of the small tube, where the cells in the row away from the small tube and the cells placed in the next row of the The small tube are adapted to exert a larger radial force and are adapted to be more flexible than the cells placed in the rows placed between the remote row and the next row.

6. The small tube according to claim 5, characterized in that the cells in the remote row and the next row are of a different size than the cells placed in the rows placed between the remote row and the next row of the small tube.

7. The small tube according to claim 5, characterized in that the cells in the remote row and the next row are of a thinner caliber than the caliber of the material used in the cells placed between the remote row and the next row of the small tube.

8. The small tube according to claim 5, characterized in that the cells in the remote row and the next row are made of a material that is more flexible than the material used in the cells placed between the remote row and the next row of the small tube .

9. An expandable small tube, characterized in that it comprises: a) a plurality of interconnected flexible cells defining a small tube having a proximal end and a remote end and a longitudinal axis, the cells arranged or distributed in a plurality of interconnected flexible rows, placed along the longitudinal axis of the small tube with a remote row placed at the far end of the small tube and a next row positioned at the proximal end of the small tube, each of the flexible cells comprises a first element, a second element, a third element and, a fourth element; b) a first loop or C-shaped loop placed between the first element and the third element; c) a second loop or C-shaped loop placed between the second element and the fourth element; d) a first flexible connector placed between the first element and the second element; and e) a second flexible connector placed between the third element and the fourth element, wherein the cells of the remote row are provided with first and third elements that are shorter than the second and fourth elements in the remote row, and wherein the The remote row is provided with first and second flexible connectors that are more flexible than the flexible connectors in the cells in the other rows of the small tube.

10. The small tube according to claim 9, characterized in that the first and second flexible connectors have a U-shape.

11. The small tube according to claim 9, characterized in that the first and second flexible connectors have the shape of S.

12. The small tube according to claim 9, characterized in that the first and second flexible connectors have the shape of Z.

13. The small tube according to claim 9, characterized in that the first and second elements in the remote row are approximately 15% shorter than the second and fourth elements in the remote row.

14. The small tube according to claim 9, characterized in that the first and second flexible connectors in the remote row are narrower than the first and second flexible connectors in the cells in the other rows of the small tube.

15. The small tube according to claim 14, characterized in that the first and second flexible connectors in the remote row are approximately 40% narrower than the first and second flexible connectors in the cells in the other rows of the small tube.

16. The small tube according to claim 9, characterized in that the first and second flexible connectors in the remote row are annealed to impart a hardness that is different than the hardness of the flexible connectors in the other rows of the small tube.

17. The small tube according to claim 9, characterized in that the small tube is comprised of NiTi and the first and second flexible connectors in the row remote from the small tube are in a martensitic phase and the remaining portions of the small tube are in the austenitic phase .

18. The small tube according to claim 9, characterized in that the cells in the remote row are of a thinner caliber than the caliber of the material used in the cells placed between the remote row and the proximal end of the small tube.

19. The small tube according to claim 9, characterized in that the cells in the remote row are made of a material that is more flexible than the material used in the cells placed between the remote row and the proximal end of the small tube.

20. An expandable small tube, characterized in that it comprises: a) a plurality of interconnected flexible cells defining a small longitudinal tube having a proximal end and a remote end and a longitudinal axis, the cells arranged or distributed in a plurality of interconnected flexible rows, placed along the longitudinal axis of the small tube with a remote row placed at the far end of the small tube and a next row placed at the proximal end of the small tube, each of the flexible cells comprises a first element, a second element, a third element, and a fourth element; b) a first loop or C-shaped loop placed between the first element and the third element; c) a second loop or C-shaped loop placed between the second element and the fourth element; d) a first flexible connector placed between the first element and the second element; and e) a second flexible connector placed between the third element and the fourth element, wherein the cells of the remote row are provided with first and third elements that are shorter than the second and fourth elements in the remote row, and where in the remote row, and in the row next to the remote row, are provided with first and second flexible connectors that are more flexible than the flexible connectors in the other rows of the small tube.

21. The small tube according to claim 20, characterized in that the first and second flexible connectors are U-shaped.

22. The small tube according to claim 20, characterized in that the first and second flexible connectors have the shape of S.

23. The small tube according to claim 20, characterized in that the first and second flexible connectors have the shape of Z.

24. The small tube according to claim 20, characterized in that the first and third elements in the remote row are approximately 15% shorter than the second and fourth elements in the remote row.

25. The small tube according to claim 20, characterized in that the first and second flexible connectors in the remote row and in the row next to the remote row are narrower than the first and second flexible connectors in the cells in the other rows of the tube little.

26. The small tube according to claim 25, characterized in that the first and second flexible connectors in the remote row and in the row next to the remote row are approximately 40% narrower than the flexible connectors in the cells in the other rows of the tube little.

27. The small tube according to claim 20, characterized in that the first and second flexible connectors in the remote row and in the row next to the remote row are annealed to impart a hardness that is different from the hardness of the flexible connectors in the other rows of small tube.

28. The small tube according to claim 20, characterized in that the small tube is comprised of NiTi and the first and second flexible connectors in the remote row and the row next to the remote row are in a martensitic phase and the remaining portions of the small tube they are in the austenitic phase.

29. The small tube according to claim 20, characterized in that the cells in the remote row and in the row next to the remote row are of a thinner caliber than the caliber of the material used in the cells placed in the other rows of the small tube .

30. The small tube according to claim 20, characterized in that the cells in the remote row and the row next to the remote row are made of a material that is more flexible than the material used in the cells placed in the other rows of the small tube .

31. An expandable small tube, characterized in that it comprises: a) a plurality of flexible cells defining a small tube having a proximal end and a remote end and a longitudinal axis, the cells arranged or distributed in a plurality of flexible rows along the length of the longitudinal axis with a remote row placed at the far end of the small tube and a next row placed at the proximal end of the small tube, each of the flexible cells comprises a first element, a second element, a third element, and a fourth element; b) a first loop or C-shaped loop placed between the first element and the third element; c) a second loop or C-shaped loop placed between the second element and the fourth element; d) a first flexible connector placed between the first element and the second element; and e) a second flexible connector placed between the third element and the fourth element, wherein the cells of the remote row are provided with first and third elements that are shorter than the second and fourth elements in the remote row, and where the cells of the next row are provided with the second and fourth elements that are shorter than the first and third elements in the next row, and where the row is distant, and the row next to the row away, and the row next and the row The row at the next row is provided with first and second flexible connectors that are more flexible than the flexible connectors in the other rows of the small tube.

32. The small tube according to claim 31, characterized in that the first and second flexible connectors are U-shaped.

33. The small tube according to claim 31, characterized in that the first and second flexible connectors have the shape of S.

34. The small tube according to claim 31, characterized in that the first and second flexible connectors have the shape of Z.

35. The small tube according to claim 31, characterized in that the first and second flexible connectors in the remote row, the row next to the remote row, the next row, and the row away from the next row are narrower than the rows. first and second flexible connectors in the cells placed in the other rows of the small tube.

36. The small tube according to claim 31, characterized in that the first and second flexible connectors in the remote row, and the row next to the remote row, the next row, and the row away from the next row are narrower than the first and second flexible connectors in the cells placed in the other rows of the small tube.

37. The small tube according to claim 36, characterized in that the first and second flexible connectors in the remote row, the row next to the remote row, the next row, and the row distant with respect to the next row are approximately 40% more narrower than the first and second flexible connectors in the cells placed in the other rows of the small tube.

38. The small tube according to claim 31, characterized in that the flexible connectors in the remote row, the row next to the remote row, the next row, the row distant with respect to the next row, are annealed to impart a hardness which is different from the hardness of the first and second flexible connectors in the cells placed in the other rows of the small tube.

39. The small tube according to claim 31, characterized in that the small tube is comprised of NiTi and the first and second flexible connectors in the remote row, the row next to the remote row, the row next, and the row away with with respect to the next row they are in a martensitic phase and the remaining portions of the small tube are in the austenitic phase.

40. The small tube according to claim 31, characterized in that the cells in the remote row, the row next to the remote row, the next row, and the row remote to the next row are of a caliber thinner than the caliber of the material used in the cells placed in the other rows of the small tube.

41. The small tube according to claim 31, characterized in that the cells in the remote row, the row next to the remote row, the next row, and the row distant with respect to the next row of the small tube are made of a material that It is more flexible than the material used in the cells placed in the other rows of the small tube.

42. An expandable small tube, characterized in that it comprises: a plurality of flexible cells defining a small tube having a proximal end and a remote end, the small tube provided with means for imparting a radial force at the remote end that is greater than the force radial in the portion of the small tube near the far end.

43. The small tube according to claim 42, characterized in that it is further provided with means for imparting a flexibility to the far end of the small tube that is greater than the flexibility of that portion of the small tube near the far end.

44. An expandable small tube, characterized in that it comprises: a plurality of flexible cells defining a small tube having a proximal end and a remote end, the small tube provided with means for imparting a radial force at its proximal and remote ends that is greater than the radial force of that portion of the small tube placed between the proximal and remote ends.

45. The small tube according to claim 44, characterized in that it is further provided with means for imparting flexibility to the far end of the small tube and to the proximal end of the small tube which is greater than the flexibility of that portion of the small tube placed between the proximal ends. and away.

46. A small expandable tube for treating a lumen or cavity having a unique feature along a portion of the lumen or cavity, characterized in that it comprises: a plurality of interconnected flexible cells, the cells arranged or distributed in a plurality of interconnected flexible rows define a small tube having a proximal end and a remote end and a longitudinal axis, wherein at least one of the rows is adapted to accommodate the unique feature of that portion of the lumen or cavity in contact with the adapted die.

47. A small expandable tube for treating a lumen or cavity having a non-uniform diameter, characterized in that it comprises: a plurality of interconnected flexible cells, the cells arranged or distributed in a plurality of interconnected flexible rows defining a small tube having a proximal end and a remote end and a longitudinal axis, wherein at least one of the rows is adapted to accommodate the non-uniform diameter of the portion of the lumen or cavity in contact with the adapted die.

48. A small expandable tube for treating a lumen or cavity having a non-uniform radial force, characterized in that it comprises: a plurality of interconnected flexible cells, the cells arranged or distributed in a plurality of interconnected flexible rows defining a small tube having one end next and a far end and a longitudinal axis, wherein at least one of the rows is adapted to accommodate the non-uniform radial force of the portion of the lumen or cavity in contact with the adapted die.

49. A small expandable tube for treating a lumen or cavity having non-uniform longitudinal flexibility, characterized in that it comprises: a plurality of interconnected flexible cells, the cells arranged or distributed in a plurality of interconnected flexible rows defining a small tube having one end next and a far end and a longitudinal axis, wherein at least one of the rows is adapted to accommodate the non-uniform longitudinal flexibilty of the lumen portion or cavity in contact with the adapted row.

50. The small tube according to claim 46, characterized in that one of the plurality of rows placed between the proximal end and the far end is provided with a cell size that is larger than the cells in the remaining rows.