STENT AND STENTING METHOD

Abstract

Provided is a stent for deployment in the Eustachian tube and other body passageways that supports the walls and assists in the natural opening of passage without hindering the natural closing operation.

Claims

1-30. (canceled)

31. A stent with a peripheral scaffold being intrinsically biased into an expanded state with a length defined between a proximal and distal end of the scaffold; wherein the scaffold has a longitudinal plane of symmetry extending between the two ends along the stent; and wherein inwardly-directed force in a direction normal to the plane of symmetry causes an inwardly directed displacement that is larger than that caused by the same inwardly-directed force applied in a direction parallel to the plane of symmetry.

32. The stent of claim 31, wherein the scaffold is axial non-symmetric.

33. The stent of claim 32, wherein the scaffold has a non-circular cross-section and is constituted by two mirror-symmetric parts linked to one another at both ends.

34. The stent of claim 31, wherein the scaffold comprises an array of cells, wherein the cells are one or a combination of closed and open cells and wherein the relative proportion of closed an open cells varies in different portions of the scaffold and wherein the cells in at least one portion of the scaffold are of different sizes than those of at least one other portion.

35. The stent of claim 31, wherein the scaffold is formed by generally zig-zagging struts extending between the two opposite ends with oppositely oriented apexes, consecutive apexes with the same orientation separated from one another by an apex distance and consecutive opposite apexes are separated by an amplitude length and wherein the struts define a generally sinusoidal-shaped or Z-shaped curve.

36. The stent of claim 35, wherein opposite apexes of adjacent struts are circumferentially connected to define radial rings.

37. The stent of claim 35, wherein one or more of (i) the apex distance, (ii) the amplitude length and (iii) the strut's width in at least one portion of the scaffold is different than in at least one other portion.

38. The stent of claim 37, wherein the scaffold is configured to a larger displacement for a defined forces applied at the proximal end than at the distal end.

39. The stent of claim 31, wherein the scaffold has in its expanded state an oversize in at least one portion of the scaffold than the corresponding portion of the lumen in which it is to be deployed.

40. The stent of claim 31, comprising a tailing arm at the proximal end to aid in stent removal and a thread, cable, wire, suture or tab at the proximal end to aid in stent removal.

41. The stent of claim 31, comprising anchoring elements integral with the scaffold.

42. The stent of claim 31, for deployment in the Eustachian tube.

43. A stent with a peripheral scaffold being intrinsically biased into an expanded state with a length defined between a proximal and distal end of the scaffold; wherein the scaffold has a longitudinal plane of symmetry extending between the two ends along the stent; and wherein the scaffold is constituted by two mirror-symmetric parts linked to one another at both ends.

44. The stent of claim 43, wherein inwardly-directed force in a direction normal to the plane of symmetry causes an inwardly directed displacement that is larger than that caused by the same inwardly-directed force applied in a direction parallel to the plane of symmetry and optionally causes at a proximal portion of the scaffold causes an inwardly directed displacement that is larger than that caused by the same inwardly-directed force in a direction normal to the plane of symmetry at a more distal portion.

45. The stent of claim 43, wherein the scaffold has a non-circular cross-section and comprising an array of cells.

46. The stent of claim 43, wherein the scaffold is configured to a larger displacement for defined forces applied at different portions of the scaffold.

47. The stent of claim 43, wherein the scaffold has in its expanded state an oversize in at least one portion of the scaffold than the corresponding portion of a lumen in which it is to be deployed.

48. The stent of claim 43, wherein the proximal segment and the distal segment of the stent are mirror images of one another.

49. The stent of claim 43, comprising a tailing arm at the proximal end to aid in stent removal, a threads, cable, wire suture or tab at the proximal end to aid in stent removal and an anchoring elements integral with the scaffold.

50. A stent deployment system for deploying a stent of claim 31.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0050] FIG. 1 is a schematic representation of a stent of an embodiment of this disclosure deployed in the ET.

[0051] FIGS. 2A and 2B are views from the direction of arrow II in FIG. 1 in respective open and closed state of the ET.

[0052] FIG. 3 shows a stent of an embodiment of this disclosure having different dimensions in different portions along its length to fit corresponding portions of the ET and being configured such that its proximal end will jut out of the ET to permit stent removal.

[0053] FIG. 4 shows a stent configured for deployment in a specific portion of the ET, typically within the cartilaginous portion distal from the natural valve.

[0054] FIG. 5 shows a stent of this disclosure provided with a braided tail end.

[0055] FIG. 6 is a schematic representation of a stent with an annexed leg that extends into the nasopharynx cavity.

[0056] FIG. 7 is a schematic representation of an embodiment of mirror-symmetric stent.

DETAILED DESCRIPTION OF EMBODIMENTS

[0057] The invention will now be further described with reference to some specific embodiments, schematically depicted in the annexed drawings. These embodiment concern ET stents but it should be understood that these embodiments are intended to illustrate and exemplify the teachings of this disclosure and in no way is it intended to be limiting; rather, they are examples of the broader teaching of this disclosure.

[0058] Reference is first being made to FIG. 1 showing a stent 100 according to an embodiment of this disclosure, deployed within the ET. Stent 100 has a peripheral scaffold 102 formed by a plurality of struts 104 that follow a generally sinusoidal path extending between the proximal end 106 and the distal end 108 of the stent. Opposite apexes, in adjacent struts of this sinusoidal structure, are connected to one another at connection points 110 to thereby define a plurality of closed cells 112.

[0059] As can be seen in FIG. 2A the stent has an overall elliptical or oval cross-section defining a longitudinal plane of symmetry represented by dashed line 120, separating between the two sides that are mirror images of one another. The stent is thus configured such that an inwardly directed force in the direction normal to plane 120, as represented by arrow 122, would cause larger displacement than a similar force applied in a vertical inward direction, represented by arrow 124. Thus, when the walls of the proximal end of the ET close upon relaxation of the surrounding smooth muscles from the open state seen in FIG. 2A to the closed state seen in FIG. 2B, the two lateral walls displace inwardly permitting closure of the valve.

[0060] FIGS. 3-5 illustrate different stent configurations. In FIG. 3 stent 130 has segments with different cross-sectional dimensions including a distal segment 132 with a narrow dimension; and a proximal segment 134 with a wider dimension. The cells in segment 134 are larger and hence with larger apex distance and/or amplitude length and accordingly the rigidity and displacement resistance is overall lower than in the distal segment 132. There may also be variations in cell size, apex distance and amplitude length in upper and lower portions, as compared to lateral portions of the stent.

[0061] FIG. 4 illustrates a stent 138 configured for deployment in only a portion of the ET and FIG. 5 illustrates a stent 140 which has a tail end 142 constituted by the braided ends of the struts.

[0062] FIG. 6 illustrates a stent 146 with an arm 148 annexed to the proximal end 150 of the scaffold. The stent is deployed in an cartilaginous portion of the ET distal from the natural valve at the ET's proximal end and the arm 148, thus, crosses through the natural valve to engage with an anatomical feature, e.g. a muscle, that moves when swallowing. On such engagement, the arm 148 be pushed and apply pressure on the natural valve. The natural valve will be forced open and allow the ET to ventilate.

[0063] FIG. 7 illustrates a mirror-symmetric stent 160 that comprises two mirror-symmetric parts 162A and 162B extending lengthwise between the proximal and distal ends and comprising respective struts couples 164A, 165A and 164B, 165B, each integrated with its mirror image strut at integration points 170 and 172. The struts couples are linked to one another, by a pair of lateral bars 166A, 167A and 166B, 167B. Each of parts 162A and 162B form a generally vertical slightly outwardly-curved plane. This structure provides for flexibility of the scaffold only in the lateral direction about the terminal points of integration 170 and 172 and permitting very little, if any, inwardly-directed vertical displacement.

[0064] As cab be appreciated, the above stents are deployed such that the stents vertical portions juxtapose the lateral portions of the passageway and, consequently, permit a degree of lateral inward displacement of the walls of the.

[0065] The stent of this disclosure may be anchored by forces resulting from variations in radial force, cross-section and/or its eccentricity along its longitudinal axis.

[0066] The stent of this disclosure may also include means to hold the stent in place and avoid migration. Such means may comprise bars or other projections that protrude from the stent cylindrical envelope and anchor the stent in place. In case the stent is made by laser cutting, such bars or other projections may be formed at multiple locations along the stent length. Alternatively, zigzag pieces of the laser cut stent may be set to protrude from the stent cylindrical envelope (“fish scaling”) and help resist migration.