MXPA99004166A - Stent bifurcado with opening of improved side branching and method for factory - Google Patents

Abstract

The present invention relates to a bifurcated stent for insertion into a bifurcated vessel, such as a blood vessel. In one embodiment, a first sheet is formed in a first derivation, a second sheet is formed in a second derivation, a third sheet is formed in a shank, and the two derivations are joined to the shank. In a second embodiment, a first blade is formed in a member having a first branch and half a rod, a second blade is formed in a second member having a second branch and a half of a piston rod, and the two halves of the stem to form the bifurcated stent. In a third embodiment, the stent comprises two sections that are inserted and assembled in series inside the vessel, in the place of the bifurcation to be treated.

Description

STENT FORCED WITH OPENING OF IMPROVED SIDE BRANCH AND METHOD TO MANUFACTURE IT Field of the Invention The present invention relates to stents (blood vessel implants), and more particularly to bifurcated stents and methods for making bifurcated stents for insertion into a branching vessel.

Background of the Invention Stents are well known in the art. These are typically formed of a cylindrical metal mesh that can expand when pressure is applied internally. Alternatively, these can be formed from wire wound into a cylindrical shape or sheets of material formed into a cylindrical shape. Stents are devices that are usually implanted inside body canals, including the vascular system, to reinforce collapsed, partially occluded, weakened, or abnormally dilated sections of the blood vessel. Stents have also been successfully implanted in other areas, for example, the urinary tract or the bile duct, to reinforce these bodily conduits. The Patent of the United States of North America Number 4,994,071 (MacGregor) discloses an expandable bifurcation stent having a main cylindrical grid formed of interconnected flexible wire. Similarly, two additional cylindrical grids are constructed, which have smaller diameters than the main grid. The main grille includes a flexible wire that interconnects the main grille to one of the additional grids. A second flexible wire interconnects the main grid to the other additional grid. The flexible wires form base structures that extend axially along the length of the main grid, and along each of the additional grids. A disadvantage of this bifurcation stent is the complex nature of the interconnection of the flexible wires forming the base structures with the curve structure of each grid.

SUMMARY OF THE INVENTION The present invention solves these and other disadvantages of the prior art, by providing bifurcated stents and methods for manufacturing and deploying bifurcated stents having one shank portion and two bypass portions. In a first embodiment of the invention, a bifurcated stent is made by providing three sheets molded to a desired pattern, wherein two sheets are substantially the same size, and the third sheet is wider than any of the first two sheets. Each of the sheets is formed into tubes by folding up the longitudinal edges, and forming a joint by welding. The larger blade forms a tube that acts as the stem portion of the bifurcated stent, and the other blades form tubes that act as the branching portions of the bifurcated stent. The two branch portions are then joined to the rod portion to form the bifurcated stent. In a second embodiment of the invention, the bifurcated stent is formed by preparing two stent sheets. For each sheet, the longitudinal edges of a portion of the sheet are folded up and secured to each other to form one of the two branching portions of the bifurcated stent. The remaining free edges of each of the two sheets are then joined to form the stent portion of the stent. In a third embodiment, the bifurcated stent comprises first and second tubular portions. The first portion has a proximal end that forms the stem portion, and a distal end that forms one of the branching portions of the bifurcated stent. A branching opening is placed between the proximal end and the distal end of the first portion. The second portion is inserted into the longitudinal bore of the stem portion of the first portion, and is advanced through the branch opening, such that it protrudes beyond the branch opening, to form a second branch. . When the second portion is expanded, the proximal end of the second portion engages the material defining the branch opening, in order to secure the second branch in the desired position. It is an object of this invention to provide a method for making a bifurcated stent, comprising the steps of: a) preparing a first sheet having a first edge, a second edge, a third edge, and a fourth edge; b) prepare a second sheet that has a first edge, a second edge, a third edge, and a fourth edge; c) prepare a third sheet that has a first bank, a second bank, a third bank, and a fourth bank; d) sticking the second edge to the third edge of the first sheet, to form a first tubular branch portion having a proximal end and a distal end; e) sticking the second edge to the third edge of the second sheet, to form a second tubular branch portion having a proximal end and a distal end; f) sticking the second edge to the third edge of the third sheet, to form a portion of tubular rod having a proximal end and a distal end; and g) attaching the proximal end of the first branch portion and the proximal end of the second branch portion to the distal end of the rod portion.

It is another object of this invention to provide a method for making a bifurcated stent, comprising the steps of a) preparing a first sheet having a proximal end and a distal end; b) deforming the distal end of the first sheet, to form a first branch, and deforming the proximal end of the first sheet, to form a first half of the rod; c) preparing a second sheet having a proximal end and a distal end; b) deforming the distal end of the second blade, to form a second branch, and deforming the proximal end of the second blade, to form a second half of the rod; and e) joining the first half of the rod to the second half of the rod to form a rod. It is still another object of this invention to provide a method for making a bifurcated stent, comprising the steps of a) preparing a first expandable tubular member having a proximal end and a distal end, and a longitudinal perforation therethrough, the first The tubular member is provided with a branching opening positioned between the proximal end and the distal end, the branching opening communicating with the longitudinal perforation, and the aperture dimensioned and adapted to receive and secure a second expandable tubular member; b) depositing the first expandable tubular member in a bifurcated vessel having a first lumen and a second lumen, such that the first expandable member is placed inside the first lumen, and the branch opening communicates with the second lumen; c) expanding the first expandable member in a sufficient amount, to secure the first expandable member in the first lumen; d) preparing a second expandable tubular member having a proximal end and a distal end, and having a longitudinal bore therethrough; e) widen the branching opening; f) depositing the second expandable tubular member in the branch opening, such that the distal end of the second expandable tubular member is placed inside the second lumen, and the proximal end of the second expandable tubular member is placed inside the longitudinal perforation of the first longitudinal member; and g) expanding the second expandable tubular member in an amount sufficient to secure the second expandable tubular member within the second lumen, and within the branch opening. It is still another object of this invention to provide a method for making a bifurcated stent, comprising the steps of: a) preparing a sheet having a proximal end, a distal end, a longitudinal axis, and a circumferential axis, the sheet provided with : a first side having a proximal portion having a proximal end and a distal end, and a distal portion having a proximal end and a distal end; a second side having a proximal end and a distal end, the second side positioned between the proximal end of the sheet, and the distal end of the sheet; a third side having a proximal end and a distal end, the third side positioned between the distal end of the second side, and the distal end of the sheet; a fourth side positioned between the proximal end of the proximal portion of the first side, and the proximal end of the second side; a fifth side positioned between the distal end of the distal portion of the first side, and the distal end of the third side, the fifth side having a length that is shorter than the length of the fourth side; and a sixth side placed between the second side and the third side; b) joining the second side to the proximal portion of the first side, and joining the third side to the distal portion of the first side, to form a first expandable tubular member having a longitudinal bore, defining a longitudinal axis, the fourth side defining a proximal stent opening communicating with the longitudinal perforation, the fifth side defining a distal stent opening communicating with the longitudinal perforation, and the sixth side and the proximal end of the third side, and the proximal end of the distal portion of the first side, defining a lateral branching opening, which communicates with the longitudinal perforation and is dimensioned and adapted to receive and secure a second expandable tubular member; c) depositing the first expandable tubular member in a bifurcated vessel having a first lumen and a second lumen, such that the first expandable tubular member is positioned within the first lumen, and the branch opening communicates with the second lumen; d) expanding the first expandable tubular member in an amount sufficient to secure the first expandable tubular member in the first lumen; e) preparing a second expandable tubular member having a proximal end and a distal end, and having a longitudinal bore therethrough; f) depositing the second expandable tubular member within the branch opening of the first tubular member, such that the distal end of the second expandable tubular member is positioned within the second lumen, and the proximal end of the second expandable tubular member is placed inside. of the longitudinal perforation of the first tubular member; and g) expanding the second expandable tubular member in an amount sufficient to secure the second expandable tubular member within the second lumen, and within the branch opening.

It is still another object of this invention to provide a bifurcated stent comprising: a) a first tubular member having a proximal end and a distal end, and a longitudinal bore therethrough, defining a longitudinal axis, the first tubular member comprising a sheet having a proximal end, a distal end, a longitudinal axis, and a circumferential axis, the sheet provided with: a first side having a proximal portion having a proximal end and a distal end, and a distal portion having a proximal end and a distant end; a second side having a proximal end and a distal end, the second side positioned between the proximal end of the sheet, and the distal end of the sheet; a third side having a proximal end and a distal end, the third side positioned between the distal end of the second side, and the distal end of the sheet; a fourth side positioned between the proximal end of the proximal portion of the first side, and the proximal end of the second side; a fifth side positioned between the distal end of the distal portion of the first side, and the distal end of the third side, the fifth side having a length that is shorter than the length of the fourth side; and a sixth side placed between the second side and the third side; b) means for joining the second side to the proximal portion of the first side, and the third side to the distal portion of the first side, such that the fourth side defines a proximal stent opening that communicates with the longitudinal perforation, the fifth side defines a distant stent opening communicating with the longitudinal perforation, and the sixth side and the proximal end of the third side, and the proximal end of the distal portion of the first side, define a lateral branch opening, which communicates with the longitudinal perforation and is dimensioned and adapted to receive and secure a second tubular member; and c) a second tubular member having a proximal end and a distal end, and having a bore therethrough, the second tubular member positioned within the branch opening, such that the proximal end of the second tubular member is placed inside the longitudinal perforation of the first tubular member. It is another object of this invention to provide a method for making a bifurcated stent, comprising the steps of: a) cutting a proximal member of a first expandable tube having a first transverse diameter, the proximal member having a proximal end and a distal end , and a longitudinal perforation through it; b) cutting a distal member of a second expandable tube having a second transverse diameter smaller than the first diameter of the first tube, the distal member having a proximal end and a distal end, and a longitudinal perforation therethrough; c) attaching a portion of the distal end of the proximal member, to a portion of the proximal end of the distal member, such that the longitudinal perforation of the proximal member is in fluid communication with the longitudinal perforation of the distal member, to form a first tubular member expandable having a proximal end and a distal end, and a longitudinal perforation therethrough, the unattached portion of the distal end of the proximal member, and the unattached portion of the proximal end of the distal member defining a lateral branching opening that is communicates with the longitudinal perforation of the first tubular member, and is dimensioned and adapted to receive and secure a second expandable tubular member; c) depositing the first expandable tubular member in a bifurcated vessel having a first lumen and a second lumen, such that the first expandable member is placed inside the first lumen, and the branch opening communicates with the second lumen; d) expanding the first expandable tubular member in a sufficient amount to secure the first expandable tubular member in the first lumen; e) preparing a second expandable tubular member having a proximal end and a distal end, and having a longitudinal bore therethrough; f) depositing the second expandable tubular member in the branch opening of the first tubular member, such that the distal end of the second expandable tubular member is placed inside the second lumen, and the proximal end of the second expandable tubular member is placed inside of the second lumen. the longitudinal perforation of the first longitudinal member; and g) expanding the second expandable tubular member in an amount sufficient to secure the second tubular member within the second lumen, and within the branch opening. It is still another object of this invention to provide a bifurcated stent comprising: a) a first tubular member having a proximal end and a distal end, and a longitudinal bore therethrough, the first tubular member comprising a proximal member and a member distant, the proximal member having a first transverse diameter, a proximal end and a distal end, and a longitudinal perforation therethrough, and the distal member having a second transverse diameter smaller than the first diameter, a proximal end and an end distant, and a longitudinal perforation therethrough; b) means for attaching a portion of the distal end of the proximal member to a portion of the proximal end of the distal member, such that the longitudinal perforation of the proximal member is in fluid communication with the longitudinal perforation of the distal member, to form the first member tubular, the unattached portion of the distal end of the proximal member, and the non-unique portion of the proximal end of the distal member defining a lateral branch opening communicating with the longitudinal perforation of the first tubular member, and is dimensioned and adapted to receive and securing a second expandable tubular member; and c) a second tubular member having a proximal end and a distal end, and having a longitudinal bore therethrough, the second tubular member positioned and secured within the branch opening, such that the proximal end of the second The tubular member is positioned inside the longitudinal perforation of the first tubular member.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a bifurcated stent, manufactured in accordance with the present invention.

Figure 2 shows the leaves that are used to form the branches and the stent shank shown in Figure 1. Figure 3 shows the leaves shown in the figure.

Figure 2, after these have been rolled into a tubular shape. Figure 4 is a perspective view of the tubes shown in Figure 3, before assembling them. Figure 5 is an end view of the tubes shown in Figures 3 and 4, after they have been assembled to form a stent. Figure 6 is a top view of the apparatus shown in Figure 5 assembled. Figure 7 shows the blades that are used to form another embodiment of a bifurcated stent, manufactured in accordance with the invention. Figure 7B shows the sheets that are used to form another embodiment of a bifurcated stent, manufactured in accordance with the invention. Figure 8 shows the leaves of Figure 7, with demarcation points. Figure 9 shows the sheets of Figure 8 after they have been rolled into a tubular shape. Figure 9B shows the sheets of Figure 7B after they have been rolled into a tubular shape. Figure 10 shows the tubes of Figure 9 just before assembly. Figure 10B shows the tubes of Figure 9B just before assembly. Figure 11 is a side view of the tubes shown in Figures 9 and 10, after assembly. Figure 11B is a side view of the tubes shown in Figures 9B and 10B, after assembly. Figure 12 is an end view of the apparatus shown in Figure 11 assembled. Figure 12B is an end view of the apparatus shown in Figure 11B assembled. Figure 12C shows an alternative embodiment of a pattern that can be used in place of the patterns shown in Figures 7 and 7B. Figure 13 shows a rod and a first branch portion, and a second branch portion, which are used to form another embodiment of a bifurcated stent, manufactured in accordance with this invention. Figure 14 shows guidewires placed in the trunk lumen and branched lumen to be treated. Figure 15 shows the rod and the first branch portion shown in Figure 13, placed in catheters and guide wires, before its introduction into the lumen to be treated. Figure 16 shows the rod and the first branch portion shown in Figure 13, after they have been deposited at the bifurcation to be treated, and before their expansion. Figure 17 shows the second derivation portion shown in Figure 16, after it has expanded. Figure 18 shows the expansion of the branching opening. Figure 19 shows the second unexpanded branch portion, placed in the branch opening. Figure 20 shows the expansion of the second branch portion shown in Figure 19. Figure 21 shows the bifurcated stent assembled, placed in the bifurcated lumen to be treated. Figure 22 shows a sheet that is used to form a first expandable tubular member. Figure 23 shows the sheet of Figure 22, before it has been formed into a first expandable tubular member. Figure 24 shows the first expandable tubular member of Figure 23, with catheters inserted in the longitudinal perforation and the lateral branch opening. Figure 25 shows the first expandable tubular member of Figure 24, after expansion with a second unexpanded tubular member being introduced into the lateral branch opening. Figure 26 shows the first expandable tubular member of Figure 24, after expansion with a second unexpanded tubular member positioned in the lateral branch opening. Figure 27 shows the second tubular member of Figure 26, after it has expanded. Figure 28 shows a side view of a proximal member and a distal member, which are used to make an alternative embodiment of the invention. Figure 29 shows the proximal and distal members of Figure 28, after they have been connected to form a first expandable tubular member. Figure 30 is an end view of Figure 29. Figure 30A is an end view of Figure 29, showing an alternative embodiment, in which a portion of the proximal member and a portion of the distal member have been deformed, before be united Figure 31 shows the first expandable tubular member of Figure 29, with a second expandable tubular member positioned within the lateral branch opening.

Detailed Description In the embodiment illustrated in Figure 1, the bifurcation stent 5 comprises a first branch 10, a second branch 15, and a rod 20. Figure 2 shows a first sheet 25 that is used to form the first branch 10, a second blade 30 that is used to form the second branch 15, and a third blade 35 that is used to form the rod 20. The first blade 25 and the second blade 30 are substantially planar, and are dimensioned to a length and width previously determined. For many applications, the first sheet 25 and the second sheet 30 will have substantially the same dimensions, in order to produce branches 10 and 15 that are substantially of the same size, however, the branches 10 and 15, and the sheets 25 and 30 which are used to produce them, can be of different sizes, as dictated by the specific applications. The stents of this invention can be dimensioned such that when assembled they are of their final size, however, in a preferred embodiment, the stents are expandable and are sized and adapted to assume their final dimensions after expansion. The sheets 70 and 75 of the stent can be molded or etched with perforations forming a variety of patterns, as dictated by specific applications to achieve the expandable characteristics that are required, as described above. The third sheet 35 is dimensioned in such a way that when it is wound in a tube, its internal cross section can be made to accommodate the external transverse diameters of the first branch 10 and the second branch 15. The first sheet 25 has a first edge 26, a second bank 27, a third bank 28, and a fourth bank 29. The second bank 30 has a first bank 31, a second bank 32, a third bank 33, and a fourth bank 34. After it has been cut off the sheet metal to form the sheets 25, 30, and 35, this is deformed and rolled up, in order to cause the two opposite edges to meet, and create a cylinder. In the example shown in Figures 2 and 3, the edge 27 is joined to the edge 29 by a welding path 14, to form the first branch 10. The edge 32 is joined to the edge 34 by the path 19 of welding, to form the second branch 15. The edge 37 is joined to the edge 39 by the welding path 29, to form the rod 20. The edges can be joined by a variety of ways well known to those skilled in the art. technique, as appropriate for this purpose, for example, screwing, bending, welding, however, in a preferred embodiment welding is used. In a particularly preferred embodiment, spot welding is used. As shown in Figure 3, the first branch 10 has a proximal end 11, a distal end 12, and defines a longitudinal perforation 13. The second branch 15 has a proximal end 16, a distant end 17, and defines a longitudinal bore 18. The rod 20 has a proximal end 26, a distant end 27, and defines a longitudinal bore 28. Figure 4 shows the first branch 10, the second branch 15, and the rod 20 just before assembly. To form the bifurcated stent 5, the proximal end 11 of the first branch 10, and the proximal end 16 of the second branch 15 join the far end 27 of the portion 20 of the stem, such that the perforations 13, 18, and 28 longitudinals are in communication with each other. Figure 5 is an end view, and Figure 6 is a side view of the assembled apparatus. Figure 11 shows a second embodiment of a bifurcation stent, manufactured in accordance with this invention. The stent 50 is provided with a first branch 55 and a second branch 60 joined to a portion 65 of the rod. The bifurcation stent 50 is formed from a first sheet 70, and a second sheet 75, as shown in Figure 7. The sheets 70 and 75 of the stent can be molded or etched with perforations forming a variety of shapes. patterns, as dictated by specific applications to achieve the expandable characteristics required, as described above. The sheets 70 and 75 are substantially planar and have a predetermined length and width. The first sheet 70 has a first edge 71, a second edge 72, a third edge 73, and a fourth edge 74. The second sheet 75 has a first edge 76, a second edge 77, a third edge 78, and a fourth edge 79. To form the stent branches, a portion of the edge 72 is rolled to a portion of the edge 74, and a portion of the edge 77 is wound to a portion of the edge 79. Points 80, 81 are selected, 82, and 83 demarcation on leaves 70 and 75, as shown in Figure 8. These demarcation points 80, 81, 82, and 83 are selected to meet the requirement of specific applications, and can be adjusted depending on the length required for branches 55 and 60, and the length required for the shank 65. The demarcation points 80 and 81 that are equidistant from the edges 73 and 71, and the demarcation points 82 and 83 that are equidistant from banks 76 and 78, will result in a stent in the that the branches 55 and 60 have a length that is substantially equal to the portion 65 of the rod. If the demarcation points are selected so that they are closer to the edges 73 and 78 than to the edges 71 and 76, the rod will have a length that is greater than the length of each of the branches. If the demarcation points are selected so that they are closer to the edges 71 and 76 than to the edges 73 and 78, each of the branches 60 and 65 will have a length that is greater than the length of the rod 65. In one embodiment preferred, however, the demarcation points 80, 81, 82, and 83 are selected such that the proximal edges 72", 74", 77", and 79" are approximately 1/3 of the length of the edges 72, 74, 77, and 79. As shown in Figure 8, the demarcation point 80 divides the edge 72 at approximately its midpoint, between a distant edge 72 ', and a proximal edge 72". The demarcation point 810 divides the shore 742 at approximately its midpoint, between a distant shore 742 ', and a nearby shore 742' '. The demarcation point 82 divides the shore 77 at approximately its midpoint, between a distant shore 77 ', and a nearby shore 77", and the demarcation point 83 divides the shore 79 at approximately its midpoint, between a shore 79 'distant, and a nearby shore 79' '. As shown in Figure 9, to form the stent, the edge 72 'is connected to the edge 74' by a welding path 90, to form the first member 95 having a first branch portion 55, and a first half 65 'of the rod. The edge 77 'is connected to the edge 79' by a welding path 91, to form the second member 100 having a second branch portion 60 and a second half 65"of the rod. As described above, the edges can be connected in a variety of ways well known to those skilled in the art. Figure 10 shows the first member 95 and the second member 100 shown in Figure 9, in alignment just prior to assembly. To produce the bifurcated stent 50 shown in Figures 11 and 12, the edge 72"is connected to the edge 79" by the welding path 92, and the edge 74"is connected to the edge 77" by the welding path 93, such that the first half 65 'of the rod and the second half 65"of the rod form the rod 65. Figure 12 is a cross-sectional end view of the stent shown in Figure 11. In the embodiment shown in Figure 7, the sheets 70 and 75 are squares or rectangles. However, as shown in Figure 7B, the sheets 70 and 75 are not limited to this configuration. Figure 11B shows a bifurcation stent fabricated using the sheets 270 and 275 shown in Figure 7B. The stent 250 is provided with a first branch 255 and a second branch 260 joined to the portion 265 of the rod. The bifurcation stent 250 is formed from a first leaf 270 and a second leaf 275, as shown in Figure 7B. The sheets 270 and 275 of the stent can be sized and etched as described above. As shown in Figure 7B, the first sheet 270 has a first edge 271, a second edge 272, a third edge 273, a fourth edge 274, a fifth edge 275, and a sixth edge 276, a seventh edge 146, and an eighth edge 147. The second leaf 275 has a first edge 277, a second edge 278, a third edge 279, a fourth edge 280, a fifth edge 281, a sixth edge 282, a seventh edge 148, and an eighth edge 149 As shown in Figure 9B, the edge 274 is connected to the edge 276 by the welding path 290, to form the first member 295 having a first branch portion 255, and a first half 265 'of the rod. The edge 280 is connected to the edge 282 by a welding path 291, to form the second member 300 having a second branch portion 260 and a second half 265"of the rod. As described above, the edges can be connected in a variety of ways well known to those skilled in the art. Figure 10B shows the first member 295 and the second member 300 shown in Figure 9B, in alignment just prior to assembly. To produce the bifurcated stent 250 shown in Figures 11B and 12B, the edge 272 is connected to the edge 149 by the welding path 292, and the edge 278 is connected to the edge 147 by the welding path 293, such that the first half 265 'of the rod and the second half 265' 'of the rod form the rod 265. Figure 12B is a cross-sectional end view of the stent shown in Figure 11B. Figure 12C shows an alternative pattern that can be used in place of the patterns shown in Figures 7 and 7B. A third embodiment of this invention comprises two portions that are deployed in series, in two steps, and assembled inside the patient, to form a bifurcated stent. Figure 13 shows the rod and the first branch portion 110 provided with a longitudinal bore 131, and have a proximal end 115 defining a stem portion 125, and a distal end 120 defining a first branch portion 130. The second branch portion 140 is provided with a longitudinal perforation 132, and has a proximal end 145 and a distal end 150. The rod and the first branch portion 110 and the second branch portion 140 can be sized and molded or etched as described above. A branch aperture 135 is positioned between the proximal end 115 and the distal end 120 of the rod, and the first branch portion 110. The branching opening 135 is dimensioned to receive the second branch portion 140, and is adapted to engage and secure the second branch portion 140 when it has expanded into the branch opening 135. The second branch portion 140 is dimensioned and adapted to engage and secure within the branch opening 135 after expansion. Figures 14 to 21 show how the bifurcated stent is assembled into a bifurcated lumen. As shown in Figures 14 to 21, the area to be treated is a bifurcated lumen having a first lumen 190 or trunk and a second lumen 195 or branching. As shown in Figure 14, a first guide wire 155 is inserted into the branching lumen 195. As shown in Figure 15, an expandable balloon rod and the first branch portion 110 are placed on the tip of a first balloon catheter 170, such that the balloon 175 is positioned within the longitudinal perforation 131. A second balloon catheter 171 is then inserted into the longitudinal bore 131 of the rod, and the first branch portion 110 is advanced., such that the balloon 176 is placed inside the opening 135. The first catheter 170 is mounted on the first guide wire 155, and the second catheter 171 is mounted on the second guide wire 156. As shown in Figure 16, the unexpanded stem and the first branch portion 110 are guided to the area to be treated, such that the first branch portion 130 is placed inside the trunk lumen 190, and the opening 135 of branching communicates with lumen 195 of branching. The guidewire 156 facilitates the orientation of the branching opening 135 with the branching lumen 195. The size of conventional catheters and balloons is not to scale, and for clarity the details well known to those skilled in the art have been omitted. The balloon 175 is inflated, which causes the rod and the first branch portion 110 to expand, as shown in Figure 17, to secure it in the desired position. After the expansion, the external wall of the rod and the first branch portion 110 would have contact with the inner walls of the trunk lumen, however, a space has been intentionally left for clarity. The balloon 175 in the first catheter 170 is left inflated, and the balloon 176 in the second catheter 171 is then inflated to elongate the branch opening 135, as shown in Figure 18. As the branch opening 135 is lengthened , a portion of the stent, which defines the branching opening 135, is pushed forward to form a branch securing lip 180. The balloons 175 and 176 are deflated, the second catheter 171 is withdrawn, and the second guide wire 156 is left in place in the branching lumen 195. The second bypass portion 140 is then applied to the second catheter 171, such that the balloon 176 is placed in the longitudinal bore 132, and then the second catheter 171 is applied to the second guide wire 156. As shown in Figure 19, the second portion 140 of bypass a is then guided, and inserted into, the longitudinal bore 131 of the rod and the first branch portion 110, and advanced and passed through. the branch opening 135, such that the end 150 remote from the second branch portion 140 protrudes into the branch lumen 195, and the proximal end 145 communicates with the longitudinal hole 131. The balloon 176 in the second catheter 171 is partially inflated, and the balloon 175 in the first catheter 170 is then partially inflated to a pressure substantially equal to the pressure in the balloon 176. Then both balloons 175 and 176 are inflated simultaneously. substantially equal pressures. As shown in Figure 20, inflation of the balloon 176 in the second catheter 171 causes the second shunt member 140 to expand, such that its outer walls are entangled and secured to the area surrounding the opening 135. Inflation of the balloon 175 in the first catheter 170 prevents the rod and the first branch portion 110 from collapsing when the balloon 176 is inflated. After expansion, the outer walls of the second branch 140 will have contact with the inner wall. Lumen 195, however, has intentionally left a space for clarity. As shown in Figure 21, the balloons 175 and 176 are deflated, the catheters 170 and 171 and the guide wires 155 and 156 are removed, and the assembled bifurcated stent 160 is left in place. Figures 22 to 31 show an especially preferred method for making a bifurcated stent, in accordance with the invention. Figure 22 shows a sheet 300 which is used to form a first expandable tubular member 301. The blade 300 has a longitudinal axis 302, a circumferential axis 303, a proximal end 304, a distal end 305, a first side 306, a second side 307, a third side 308, a fourth side 309, a fifth side 310, and a sixth side 311. The sheet 300 can be provided with a variety of patterns, however, in a preferred embodiment the sheet 300 is provided with a plurality of expandable cells 312, adapted to be substantially flexible before the expansion of the first tubular member 301, and substantially rigid after expansion of the first tubular member 301. As shown in Figure 22, in an especially preferred embodiment, the flexible cells 312 of the sheet 300 are substantially uniform. The first side 306 of the sheet 300 has a portion 313 next, which has a proximal end 314 and a distant end 315. The first side 306 also has a distal portion 316, which has a proximal end 317 and a distal end 318. The second side 307 of the sheet 300 has a proximal end 319 and a distal end 320, and is positioned between the proximal end 304 of the sheet 300, and the distal end 305 of the sheet 300. The third side 308 of the sheet 300 it has one extreme 321 and a distal end 322, and is positioned between the distal end 320 of the second side 307 and the distal end 305 of the sheet 300. The fourth side 309 of the sheet 300 is positioned between the proximal end 314 of the proximal portion 313 of the first side 306, and the proximal end 319 of the second side 307. The fifth side 310 of the sheet 300 is positioned between the end 318 distant from the portion 316 distant from the first side 306, and the end 322 distant from the third side 308, and is provided with a section Ll that is shorter than section L2 on the fourth side 309. In a preferred embodiment, the section Ll of the fifth side 310, and section L2 of the fourth side 309 are in a ratio of approximately 5: 7. , that is, the fifth side 310 has a section Ll that is approximately 70 percent of the section L2 of the fourth side 309. In an especially preferred embodiment the sheet 300 is etched with a plurality of substantially uniform cells 312, as shown in FIG. described above, and the number of cells placed along the circumferential axis 303 of the fifth side 310, and the number of cells placed along the circumferential axis 303 of the fourth side 309 are in a ratio of approximately 5: 7. A sixth side 311 is placed between the second side 307 and the third side 308. In a particularly preferred embodiment, the first side 306, the second side 307, and the third side 308 are substantially parallel to one another, and the fourth side 309, the fifth side 310, and the sixth side 311 are substantially parallel to each other, and the first side 306, the second side 307, and the third side 308 are substantially perpendicular to the fourth side 309, the fifth side 310, and the sixth side 311. To make the first member 301 expandable tubular, the second side 307 of the sheet 300 is joined by connecting elements to the proximal portion 313 of the first side 306 of the sheet 300, and the third side 308 of the sheet 300 is joined by means of connecting elements a the portion 316 distant from the first side 306 of the sheet 300, to form a first expandable tubular member 301 having a longitudinal bore 323 defining a longitudinal axis 324, as shown in Figure 23. The joining step can be made using a divers Binding elements well known to those skilled in the art, as is suitable for this purpose, however, in a preferred embodiment the joining step is performed using screwing, bending, welding, or spot welding. In the modality shown in Figure 23, 325 spot welding has been used. After the sides have been joined as described above, the fourth side 309 defines a proximal tubular member opening or opening 326 of the stent, which communicates with the longitudinal perforation 323, and the fifth side 310 defines a tubular member opening. Distant or opening 327 of the stent, communicating with longitudinal perforation 323, as shown in Figures 23 and 26. The sixth side 311 and the proximal end 321 of the third side 308, and the proximal end 317 of the remote portion 316 of the first side 306, define a lateral branch opening 328 (as shown in Figures 23-26) dimensioned and adapted to receive and secure a second expandable tubular member 329 (shown in Figures 26-27). The branching opening 328 has a diameter DI that is larger than the diameter D2 of the unexpanded stent, that is, the branching opening 328 is larger than the proximal and distal openings 326 and 327 of the first member 301 tubular, both before and after the tubular member 301 expands. The first expandable tubular member 301 is then deposited in a bifurcated vessel having a first lumen and a second lumen, such that the first expandable tubular member is placed inside the first lumen, and the branch opening communicates with the second lumen. . In a preferred embodiment, the reservoir is by a balloon catheter, as described above. After this has been deposited, the first expandable tubular member expands in an amount sufficient to secure the first expandable tubular member in the first lumen. A second expandable tubular member 329 is then prepared, having a proximal end 330 and a distal end 331, and having a longitudinal bore 332 therethrough. The second expandable tubular member 329 (shown in Figures 25, 26, and 27) can be molded in the same manner as the sheet 300, as described above.

In a preferred embodiment, the cells 312 of the sheet 300 that is used to make the first tubular expandable member 301, and the cells 312 'of the second expandable tubular member 329 are substantially uniform. The second expandable tubular member 329 is deposited within the longitudinal perforation 323 of the first tubular member 301, as shown in Figure 25, and advanced into and beyond the branch opening 328, as shown in Figure 26. , such that the distant end 331 of the second expandable tubular member 329 is positioned within the second lumen, and the proximal end 330 of the second expandable tubular member 329 is positioned within the longitudinal bore 323 of the first tubular member 301. The second expandable tubular member 329 is then expanded in an amount sufficient to secure the second expandable tubular member 329 within the second lumen, and within the branch opening 328 of the first tubular member 301, as shown in Figure 27. Among the Advantages provided by this embodiment are that this stent provides a large branching opening, which facilitates the introduction of the second tubular member into the lateral branch or second lumen. In addition, this stent is especially suitable for carrying out the implantation of bifurcation stents in series, and also for the implantation of stents around a lateral branch before it is occluded. Figures 28 to 31 show an alternative embodiment and alternative method for making the first tubular member shown in Figures 23-27. In this embodiment the first tubular member 400 (shown in Figure 29) comprises a proximal member 401 having a proximal end 402 and a distal end 403, and a remote member 404 having a proximal end 405 and a distal end 406 , as shown in Figure 28. The proximal member 401 has a longitudinal perforation 415 and is cut from a first tube 407 having the first transverse diameter DI. The remote member 404 has a longitudinal perforation 416 and is cut from a second tube 408 having a second transverse diameter D2. D2 is smaller than DI. The tubes 401 and 404 can be etched or molded as described above, before the proximal member 401 and the remote member 404 are cut from the tubes 407 and 408. Alternatively, the proximal and distant members 401 and 404 are cut. etching or molding can be recorded after the members 401 and 404 have been cut off proximally and distantly from the tubes 407 and 408. To make the first tubular member 400, a portion of the distal end 403 of the proximal member 401 is attached, by connecting elements 417, to a portion of the proximal end 405 of the remote member 404, to form a first tubular member 400 having a proximal end 409 and a distal end 410, and a longitudinal perforation 411 therethrough, as shown in FIG. Figure 29. The members 401 and 404 can be joined using a variety of joining elements 417, as described above, however, in a preferred embodiment the connecting element that is used to connect the members 417 and 404 can be joined together. iliza is welding. Because D2 is less than DI, the unattached portion of the remote end 403 of the proximal portion 401, and the unattached portion of the proximal end 405 of the remote portion 404, define a branching opening 412, as shown in FIG. Figure 29 and Figure 30 (which is an extreme view of Figure 29). In some applications it may be desirable to have a larger portion of the remote end 403 of the proximal member 401, and the proximal end 405 of the distant member 404 have contact with each other, before they join, in order to increase the resistance of the first tubular member 400. This can be achieved by, for example, twisting, aligning, and having contact with a larger surface area of the remote end 403 of the next member 401., and a greater surface area of the proximal end 405 of the remote member 404, before joining the end 403 remote to the proximal end 405. Figure 30A is an end view of this embodiment and shows that a larger surface area of the remote end 403 and the proximal end 405 are joined, when compared to the embodiment shown in Figure 30. Figure 30A also shows that in this embodiment the branching opening 412 'is larger than the branching opening 412 shown in Figure 30. Then a second tubular member 413 can be introduced into the branching opening 412 and 412' and, as shown in FIG. described above, is expanded and secured in such a way that a portion of the second tubular member 413 communicates with the longitudinal perforation 411, to form a bifurcated stent 414 (shown in Figure 31).

Claims (56)

1. A method for making a bifurcated stent, comprising the steps of: a) preparing a sheet having a proximal end, a distal end, a longitudinal axis, and a circumferential axis, the sheet provided with: a first side having a portion next having a proximal end and a distal end, and a distal portion having a proximal end and a distal end; a second side having a proximal end and a distal end, the second side positioned between the proximal end of the sheet, and the distal end of the sheet; a third side having a proximal end and a distal end, the third side positioned between the distal end of the second side, and the distal end of the sheet; a fourth side positioned between the proximal end of the proximal portion of the first side, and the proximal end of the second side; a fifth side positioned between the distal end of the distal portion of the first side, and the distal end of the third side, the fifth side having a length that is shorter than the length of the fourth side; and a sixth side placed between the second side and the third side; b) joining the second side to the proximal portion of the first side, and joining the third side to the distal portion of the first side, to form a first expandable tubular member having a longitudinal bore, defining a longitudinal axis, the fourth side defining a proximal stent opening communicating with the longitudinal perforation, the fifth side defining a distal stent opening communicating with the longitudinal perforation, and the sixth side and the proximal end of the third side, and the proximal end of the distal portion of the first side, defining a lateral branch opening, which communicates with the longitudinal perforation and is dimensioned and adapted to receive and secure a second expandable tubular member; c) depositing the first expandable tubular member in a bifurcated vessel having a first lumen and a second lumen, such that the first expandable tubular member is positioned within the first lumen, and the branch opening communicates with the second lumen; d) expanding the first expandable tubular member in an amount sufficient to secure the first expandable tubular member in the first lumen; e) preparing a second expandable tubular member having a proximal end and a distal end, and having a longitudinal bore therethrough; f) depositing the second expandable tubular member within the branch opening of the first tubular member, such that the distal end of the second expandable tubular member is positioned within the second lumen, and the proximal end of the second expandable tubular member is placed inside. of the longitudinal perforation of the first tubular member; and g) expanding the second expandable tubular member in an amount sufficient to secure the second expandable tubular member within the second lumen, and within the branch opening.

The method of claim 1, wherein the joining step is performed using screwing.

The method of claim 1, wherein the joining step is performed using folding.

4. The method of claim 1, wherein the joining step is performed using soft solder.

The method of claim 1, wherein the joining step is performed using welding.

The method of claim 1, wherein the welding step is performed using spot welding.

The method of claim 1, wherein the fifth side has a length that is approximately 70 percent of the length of the fourth side.

The method of claim 1, characterized in that it also comprises the steps of providing the first and second tubular members with a plurality of cells, adapted to be substantially flexible before expansion, and substantially rigid after expansion.

9. The method of claim 1, characterized in that it also comprises the step of providing the sheet and the second tubular member with a pattern etched to the etching, which defines a plurality of cells.

The method of claim 9, wherein the cells are adapted to be substantially flexible prior to expansion of the first and second tubular members, and are adapted to be substantially rigid after expansion of the first and second tubular members.

The method of claim 10, wherein the cells of the sheet are substantially uniform.

The method of claim 10, wherein the cells of the second tubular member are substantially uniform.

The method of claim 10, wherein the cells of the sheet and the cells of the second tubular member are substantially uniform.

The method of claim 11, wherein the number of cells placed along the circumferential axis of the fifth side of the sheet, and the number of cells positioned along the circumferential axis of the fourth side of the sheet are in a ratio of approximately 5: 7.

15. The method of claim 1, wherein the branching opening is larger than the proximal and distal openings of the first tubular member.

The method of claim 1, wherein the first, second, and third sides are substantially parallel to one another, and the fourth, fifth, and sixth sides are substantially parallel to one another.

The method of claim 16, wherein the first, second, and third sides are substantially perpendicular to the fourth, fifth, and sixth sides.

18. A bifurcated stent comprising: a) a first tubular member having a proximal end and a distal end, and a longitudinal bore therethrough, defining a longitudinal axis, the first tubular member comprising a foil having an end next, a distal end, a longitudinal axis, and a circumferential axis, the sheet provided with: a first side having a proximal portion having a proximal end and a distal end, and a distal portion having a proximal end and an end distant; a second side having a proximal end and a distal end, the second side positioned between the proximal end of the sheet, and the distal end of the sheet; a third side having a proximal end and a distal end, the third side positioned between the distal end of the second side, and the distal end of the sheet; a fourth side positioned between the proximal end of the proximal portion of the first side, and the proximal end of the second side; a fifth side positioned between the distal end of the distal portion of the first side, and the distal end of the third side, the fifth side having a length that is shorter than the length of the fourth side; and a sixth side placed between the second side and the third side; b) means for joining the second side to the proximal portion of the first side, and the third side to the distal portion of the first side, such that the fourth side defines a proximal stent opening that communicates with the longitudinal perforation, the fifth side defines a distant stent opening communicating with the longitudinal perforation, and the sixth side and the proximal end of the third side, and the proximal end of the distal portion of the first side, define a lateral branch opening, which communicates with the longitudinal perforation and is dimensioned and adapted to receive and secure a second tubular member; and c) a second tubular member having a proximal end and a distal end, and having a bore therethrough, the second tubular member positioned within the branch opening, such that the proximal end of the second tubular member is placed inside the longitudinal perforation of the first tubular member.

19. The stent of claim 18, wherein the attachment element is a screw.

20. The stent of claim 18, wherein the joining element is a folder.

21. The stent of claim 18, wherein the joining element is a soft solder.

22. The stent of claim 18, wherein the joining element is welding.

23. The stent of claim 18, wherein the joining element is spot welding.

The stent of claim 18, wherein the fifth side has a length that is approximately 70 percent of the length of the fourth side.

The stent of claim 18, wherein the first and second tubular members are provided with a plurality of cells, adapted to be substantially flexible before expansion, and substantially rigid after expansion.

26. The stent of claim 18, wherein the sheet and the second tubular member comprise a pattern etched to etching, which defines a plurality of cells.

27. The stent of claim 26, wherein the cells are adapted to be substantially flexible prior to expansion of the first and second tubular members., and are adapted to be substantially rigid after expansion of the first and second tubular members.

28. The stent of claim 27, wherein the cells of the blade are substantially uniform.

29. The stent of claim 27, wherein the cells of the second tubular member are substantially uniform.

30. The stent of claim 27, wherein the cells of the sheet and the cells of the second tubular member are substantially uniform.

The stent of claim 28, wherein the number of cells positioned along the circumferential axis of the fifth side of the sheet, and the number of cells placed along the circumferential axis of the fourth side of the sheet are in a ratio of approximately 5: 7.

32. The stent of claim 18, wherein the branching opening is larger than the proximal and distal openings of the first tubular member.

33. The stent of claim 18, wherein the first, second, and third sides are substantially parallel to one another, and the fourth, fifth, and sixth sides are substantially parallel to one another.

34. The stent of claim 33, wherein the first, second, and third sides are substantially perpendicular to the fourth, fifth, and sixth sides.

35. A case for forming a bifurcated stent, comprising: a) a first expandable tubular member having a proximal end and a distal end, and a longitudinal bore therethrough, defining a longitudinal axis, the first expandable tubular member comprising a sheet having a proximal end, a distal end, a longitudinal axis, and a circumferential axis, the sheet provided with: a first side having a proximal portion having a proximal end and a distal end, and a distal portion that it has a near end and a distant end; a second side having a proximal end and a distal end, the second side positioned between the proximal end of the sheet, and the distal end of the sheet; a third side having a proximal end and a distal end, the third side positioned between the distal end of the second side, and the distal end of the sheet; a fourth side positioned between the proximal end of the proximal portion of the first side, and the proximal end of the second side; a fifth side positioned between the distal end of the distal portion of the first side, and the distal end of the third side, the fifth side having a length that is shorter than the length of the fourth side; and a sixth side placed between the second side and the third side; b) means for joining the second side to the proximal portion of the first side, and for joining the third side to the distal portion of the first side, such that the fourth side defines a proximal stent opening that communicates with the longitudinal bore , the fifth side defines a distant stent opening communicating with the longitudinal perforation, and the sixth side and the proximal end of the third side, and the proximal end of the distal portion of the first side, define a lateral branch opening, which communicates with the longitudinal perforation and is dimensioned and adapted to receive and secure a second expandable tubular member; and c) a second expandable tubular member having a proximal end and a distal end, and having a bore therethrough, the second expandable tubular member is dimensioned and adapted to be positioned and secured within the branch opening, in such a manner that the proximal end of the second tubular member is positioned within the longitudinal bore of the first tubular member; c) a first guidewire; d) a second guidewire; e) a first balloon catheter; and f) a second balloon catheter.

36. A method for making a bifurcated stent, comprising the steps of: a) cutting a proximal member of a first expandable tube having a first transverse diameter, the proximal member having a proximal end and a distal end, and a longitudinal bore through it; b) cutting a distal member of a second expandable tube having a second transverse diameter smaller than the first diameter of the first tube, the distal member having a proximal end and a distal end, and a longitudinal perforation therethrough; c) attaching a portion of the distal end of the proximal member, to a portion of the proximal end of the distal member, such that the longitudinal perforation of the proximal member is in fluid communication with the longitudinal perforation of the distal member, to form a first tubular member expandable having a proximal end and a distal end, and a longitudinal perforation therethrough, the unattached portion of the distal end of the proximal member, and the unattached portion of the proximal end of the distal member defining a lateral branching opening that is communicates with the longitudinal perforation of the first tubular member, and is dimensioned and adapted to receive and secure a second expandable tubular member; c) depositing the first expandable tubular member in a bifurcated vessel having a first lumen and a second lumen, such that the first expandable member is placed inside the first lumen, and the branch opening communicates with the second lumen; d) expanding the first expandable tubular member in a sufficient amount, to secure the first expandable tubular member in the first lumen; e) preparing a second expandable tubular member having a proximal end and a distal end, and having a longitudinal bore therethrough; f) depositing the second expandable tubular member in the branch opening of the first tubular member, such that the distal end of the second expandable tubular member is placed inside the second lumen, and the proximal end of the second expandable tubular member is placed inside of the second lumen. the longitudinal perforation of the first longitudinal member; and g) expanding the second expandable tubular member in an amount sufficient to secure the second tubular member within the second lumen, and within the branch opening.

37. The method of claim 36, wherein the joining step is performed using screwing.

38. The method of claim 36, wherein the joining step is performed using folding.

39. The method of claim 36, wherein the joining step is carried out using soft solder.

40. The method of claim 36, wherein the joining step is performed using welding.

41. The method of claim 40, wherein the welding step is performed using spot welding.

42. The method of claim 36, characterized in that it also comprises the step of providing the first and second tubular members with a plurality of cells, adapted to be substantially flexible before expansion, and substantially rigid after expansion.

43. The method of claim 36, characterized in that it also comprises the step of providing the proximal member of the first tubular member, the distal member of the first tubular member and the second tubular member with an etching pattern, defining a plurality of cells .

44. The method of claim 43, wherein the cells are adapted to be substantially flexible prior to expansion of the first and second tubular members, and are adapted to be substantially rigid after expansion of the first and second tubular members.

45. The method of claim 44, wherein the cells of the first tubular member, and the cells of the second tubular member are substantially uniform.

46. A bifurcated stent comprising: a) a first tubular member having a proximal end and a distal end, and a longitudinal bore therethrough, the first tubular member comprising a proximal member and a distal member, the proximal member having a first transverse diameter, a proximal end and a distal end, and a longitudinal perforation therethrough, and the distal member having a second transverse diameter smaller than the first diameter, a proximal end and a distal end, and a longitudinal bore through it; b) means for attaching a portion of the distal end of the proximal member to a portion of the proximal end of the distal member, such that the longitudinal perforation of the proximal member is in fluid communication with the longitudinal perforation of the distal member, to form the first member tubular, the unattached portion of the distal end of the proximal member, and the unattached portion of the proximal end of the distal member defining a lateral branch opening communicating with the longitudinal perforation of the first tubular member, and dimensioned and adapted to receive and securing a second expandable tubular member; and c) a second tubular member having a proximal end and a distal end, and having a longitudinal bore therethrough, the second tubular member positioned and secured within the branch opening, such that the proximal end of the second The tubular member is positioned inside the longitudinal perforation of the first tubular member.

47. The stent of claim 46, wherein the attachment element is a screw.

48. The stent of claim 46, wherein the joining element is a folder.

49. The stent of claim 46, wherein the joining element is soft solder.

50. The stent of claim 46, wherein the joining element is welding.

51. The stent of claim 50, wherein the joining element is spot welding.

52. The stent of claim 46, wherein the first and second tubular members comprise a plurality of cells, adapted to be substantially flexible before expansion, and substantially rigid after expansion.

53. The stent of claim 46, wherein the proximal member of the first tubular member, the distal member of the first tubular member, and the second tubular member comprise a pattern etched to etching, defining a plurality of cells.

54. The stent of claim 53, wherein the plurality of cells are adapted to be substantially flexible prior to expansion of the first and second tubular members, and are adapted to be substantially rigid after expansion of the first and second tubular members.

55. The stent of claim 54, wherein the cells of the first tubular member, and the cells of the second tubular member are substantially uniform.

56. A kit for forming a bifurcated stent, comprising: a) a first expandable tubular member having a proximal end and a distal end, and a longitudinal bore therethrough, the first expandable tubular member comprising a distal expandable member, the expandable proximal member having a first transverse diameter, a proximal end and a distal end, and a longitudinal perforation therethrough, and the expandable distal member having a second transverse diameter smaller than the first diameter, a proximal end and an end distant, and a longitudinal perforation therethrough; b) means for attaching a portion of the distal end of the expandable proximal member to a proximal end portion of the expandable distal member, such that the longitudinal perforation of the expandable proximal member is in fluid communication with the longitudinal perforation of the expandable distal member, so as to forming the first expandable tubular member, the unattached portion of the distal end of the expandable proximal member, and the unattached portion of the proximal end of the expandable distal member defining a lateral branch opening communicating with the longitudinal perforation of the first expandable tubular member, and is dimensioned and adapted to receive and secure a second expandable tubular member; c) a second expandable tubular member having a near end and a distal end, and having a longitudinal bore therethrough, the second expandable tubular member dimensioned and adapted to be positioned and secured within the branch opening, in such a manner that the proximal end of the second expandable tubular member is positioned within the longitudinal bore of the first tubular member; c) a first guidewire; d) a second guidewire; e) a first balloon catheter; and f) a second balloon catheter.