WO2020183385A1

WO2020183385A1 - A coronary ostium stent

Info

Publication number: WO2020183385A1
Application number: PCT/IB2020/052144
Authority: WO
Inventors: Antonio Colombo; Franco Vallana; Paolo Gaschino
Original assignee: Alvimedica Tibbi Ürünler Sanayi Ve Dis Ticaret A.S.
Priority date: 2019-03-12
Filing date: 2020-03-11
Publication date: 2020-09-17
Also published as: EP3937860A1; IT201900003579A1

Abstract

A coronary-ostium stent (10) comprises a tubular body with an inner surface (101) and an outer surface (102) having a wall thickness (d) between them. The tubular body of the stent (10) extends in a longitudinal direction (X10) between a first end (103) and a second end (104), which are opposite to one another, and comprises a first, intra-ostial, portion (10a), from the first end (103) to an intermediate region (105) of the tubular body between the first end (103) and the second end (104), and a second, extra- ostial, portion (10b), from the aforesaid intermediate region (105) to the second end (104). The first portion (10a) of the tubular body can be expanded from a radially contracted condition of insertion with a first diameter (D1) to a radially expanded condition of stenting of the ostium with a second diameter (D2). The ratio between the aforesaid wall thickness (d) and the aforesaid second diameter (D2) is greater than 0.03, preferably between 0.03 and 0.055.

Description

"A coronary ostium stent"

Technical field

The present disclosure relates to stents.

One or more embodiments may relate to stents that can be inserted into coronary ostia.

Technological background

The term "stent" is commonly used to refer to devices useful for endoluminal insertion (for example, in a blood vessel) with subsequent expansion in situ so as to obtain a local support of the lumen.

The activity of research and experimentation in the sector has become over the years extremely extensive, as witnessed, just to cite some examples, by documents such as EP 0 806 190 Al, EP 0 847 766 A2, EP 0 850 604 A2, EP 0 875 215 Al, EP 0 895 759 Al, EP 0

895 760 Al, EP 1 080 738 Al, EP 1 088 528 Al, EP 1 103 234 Al, EP 1 212 986 Al, EP 1 277 449 Al, EP 1 310 242

Al, EP 1 561 436 Al, EP 1 834 606 Al, EP 1 994 950 A2 , or EP 2 253 339 Al .

Notwithstanding the research and experimentation extensively documented in the literature, whether patent literature or not, the sector still proves receptive in regard to new methods of use, also in view of constant and continuous expanding employment of stents at a clinical level. Object and summary

The object of one or more embodiments is to provide a solution that will be able to contribute to the further development and further diffusion of techniques based upon the use of stents.

According to one or more embodiments, the above object may be achieved thanks to a stent having the characteristics recalled in the ensuing claims.

The claims form an integral part of the technical teachings provided herein in relation to the embodiments .

Brief description of the drawings

One or more embodiments will now be described, purely by way of non-limiting example, with reference to the annexed drawings, wherein:

- Figures 1 and 2 represent possible methods of use of stents according to embodiments;

- Figure 3 exemplifies possible characteristics of stents according to embodiments;

- Figure 4 further exemplifies possible modalities of use of stents according to embodiments; and

- Figure 4 is a more detailed view of a stent according to embodiments, represented in an ideal plane development .

It will be appreciated that, for clarity and simplicity of illustration, various figures may not be reproduced at one and the same scale.

Detailed description of examples of embodiments

In the ensuing description, various specific details are illustrated in order to provide an in-depth understanding of various examples of embodiments according to the description. The embodiments may be obtained without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials, or operations are not illustrated or described in detail so that the various aspects of the embodiments will not be obscured .

Reference to "an embodiment" or "one embodiment" in the framework of the present description is intended to indicate that a particular configuration, structure, or characteristic described in relation to the embodiment is comprised in at least one embodiment. Consequently, phrases such as "in an embodiment" or "in one embodiment" that may be present in various points of the present description do not necessarily refer exactly to one and the same embodiment. Moreover, particular conformations, structures, or characteristics may be combined in any adequate way in one or more embodiments.

The references used herein are provided merely for convenience and hence do not define the sphere of protection or the scope of the embodiments.

Figures 1 and 2 are a schematic representation of the proximal portion of the ascending tract of the aortic artery A. This is the portion of the aortic artery A closest to the cardiac muscle, which is able to receive the blood pumped by the left ventricle LV of the cardiac muscle through the aortic valve AV.

Designated by CO are the coronary ostia, i.e., the openings present in the wall of the aorta at the Valsalva sinuses VS through which the blood pumped by the cardiac muscle can spread towards the coronary arteries CA (only partially represented in the figures), which have the function of facilitating blood irrigation of the cardiac muscle.

A by now widespread intervention procedure envisages replacement of an aortic valve that is suffering (for example, as a result of calcification of the valve leaflets), with a prosthetic aortic valve PAV that can be located at the aortic-valve annulus so as to substitute for the natural cardiac valve in its operation .

Over the years, a wide range of prosthetic aortic valves have been developed and have asserted their validity in clinical use.

Among these, an increasingly important role is assumed by the prosthetic valves commonly referred to as "percutaneous valves", which can be implanted via a surgical operation with minimal invasiveness, for example by resorting to a positioning system (the so- called delivery system) introduced through a passage of reduced section open towards the aortic annulus, or else (in the case of percutaneous valves in the strict sense) by positioning the prosthetic valve via catheterization performed through the vascular system.

Implantation of a prosthetic aortic valve PAV of the above sort can be obtained without removing the valve leaflets of the natural valve, with the latter valve leaflets (designated by LF in the schematic representation of Figure 1) that are divaricated by the prosthetic valve PAV positioned (for example, expanded) at the implantation site and pushed towards the aortic wall, in particular at the Valsalva sinuses VS.

At least in some patients, the leaflets LF may end up extending into the coronary ostia CO (to a greater or lesser extent according to the anatomical characteristics of the patient in whom the prosthetic aortic valve is implanted) , thus possibly interfering in an undesirable way with the flow of the blood within the coronary arteries CA.

One or more embodiments may regard stents (designated as a whole by the reference 10), which can be implanted in at least one of the coronary ostia CO in such a way as to maintain the leaflets LF at a distance from the coronary ostia CO themselves, so as to facilitate (also thanks to the as a whole apertured structure of the stent 10) flow of the blood in the coronary arteries CA. Even though what follows is to be deemed by now widely adopted also in current language, by "stent" is currently meant an implantation device that comprises a tubular body provided with an apertured or openwork wall, such as a structure of a meshed type.

According to conventional modalities of use, a stent is designed for being inserted into a lumen, such as a blood vessel (by positioning it in situ, for example, by means of catheterization through the vascular system) , and then expanded radially from a diameter of introduction to a diameter of expansion, where, in the expanded condition, the stent exerts an action of support and anchorage on the lumen.

A stent as exemplified herein comprises a tubular body having an inner surface 101 and an outer surface

102 that have an apertured structure and may both present an as a whole cylindrical shape, defining between them a wall thickness of the tubular body of the stent: this wall thickness is represented schematically and designated by d in Figure 3.

In one or more embodiments as exemplified herein, the tubular body of the stent 10 extends in a longitudinal direction (represented in the figures by a longitudinal axis X10) between mutually opposite ends

103 and 104 so as to comprise:

- a first portion 10a, which is to be implanted in an intra-ostial position (i.e., within the coronary artery CA) and extends from the first end 103 to an intermediate region 105 here exemplified by an (ideal) plane transverse to the longitudinal direction X10 in an intermediate position between the ends 103 and 104; and

- a second portion 10b, which is to be located in an extra-ostial position (i.e., on the outside of the coronary ostium, projecting in the Valsalva sinus VS) and extends between the intermediate region 105 and the second end 104 of the tubular body of the stent 10.

As may be appreciated from Figures 1 and 2, a stent 10 as exemplified herein can be implanted (according to implantation procedures in themselves known) in such a way as to have the intra-ostial portion 10a that extends within the initial stretch of the coronary artery CA, facilitating anchorage in situ of the stent, and the extra-ostial portion 10b that projects on the outside of the ostium CO in the Valsalva sinus, hence within the aortic artery, with the capacity (also following upon a possible shaping as discussed in what follows) to keep the valve leaflets LF at a distance and facilitate perviousness of the ostium and hence proper irrigation of the cardiac muscle through the coronary arteries CA.

For this purpose, (at least) the first portion 10a of the tubular body 10 of the stent can be expanded from a radially contracted condition of insertion into the coronary ostium with a first diameter (represented dashed and designated by D1 in Figure 3) to a radially expanded condition in which the stent 10 performs an action of stenting (and hence support) of the coronary wall as a result of its expansion to a second diameter (designated by D2 in Figure 3) .

This fact makes it possible to realise that terms such as "coronary-ostium stent" or "intra-ostial portion" do not merely provide a functional indication, but rather denote, in a precise way, the characteristics (dimensional characteristics, but not only) of the stent 10, at least as regards the first portion 10a, designed for intra-ostial insertion.

Albeit with the typical variations of anatomical data in the population, a coronary ostium CO normally presents in an adult subject a diameter comprised between 4 and 5 mm, with values of 3 mm and 6 mm that may be encountered in certain subjects.

To be able to perform its function of coronary- ostium stent, a stent 10 as exemplified herein may consequently present (at least as regards the intra- ostial portion 10a) :

- in the radially contracted condition of insertion into the ostium, a first diameter Dl, of less than 4 mm (3 mm), such as to enable insertion into the ostium; and

- in the radially expanded condition, in which the tubular body of the stent 10 acts in a relationship of stenting with the wall of the coronary artery, a second diameter D2, of not less than 4-5 mm (6 mm), so as to enable anchorage in the ostium.

Reference to a range of values (3-4 mm or 4-5- 6 mm) takes into account the fact that, as is known to the persons skilled in the sector, stents are normally produced in assortments comprising stents of different sizes with the individual types of stents in the assortment identified, for example, by a maximum value of the diameter D2.

A stent as exemplified herein is hence suited to being produced in an assortment of stents with maximum values of the diameter D2 equal, for example, to 4.5 mm, 5 mm, 5.5 mm, and 6 mm.

A stent as exemplified herein has a wall thickness d (which can be assumed as being substantially constant throughout the length of the stent, considering the technologies of manufacture thereof) having a value such that the ratio between the wall thickness (d in Figure 2) and the diameter D2 (i.e., the diameter of the first portion 10a in the radially expanded condition) is greater than 0.03 and optionally comprised between 0.03 and 0.055: it is, hence, a stent having a wall that is, so to speak, rather "thick" - as compared to the value of the diameter in the expanded condition .

So-called "peripheral stents" (iliac-artery stents, femoral-artery stents, etc.) are in fact available presenting values of wall thickness in the region of, for example, 170 pm.

In peripheral stents of this sort, such a value of wall thickness is accompanied by a diameter of expansion greater than the diameter of expansion of a coronary-ostium stent. Consequently, in these stents the ratio d/D2 is (amply) lower than the values referred to herein.

In a complementary way, there exist stents for coronary application, where the ratio d/D2 is in actual fact greater than 0.03. These are, however, stents in which the value of diameter D2 is amply smaller than the diameter of a coronary ostium; hence, in this case, these are stents that cannot be intrinsically categorized as coronary-ostium stents.

A value of wall thickness d of 160-170 pm, such as can be used for a stent 10 according to one or more embodiments, is accompanied by a value of diameter D2 correlated to the dimensions of a coronary ostium, thus giving rise to a stent with a thick wall that is as a whole somewhat rigid and resistant to bending.

A stent according to one or more embodiments hence moves in a direction opposite to what is normally envisaged for a conventional stent, which, given that it is designed to be brought into the implantation site via catheterization through the vascular system, presents a high degree of flexibility so that it can be flexed, bent, and folded as it follows the path, which may even be rather tortuous, towards the implantation site . In one or more embodiments, the ratio between the length of the first portion 10a and the length of the second portion 10b of the tubular body of the stent 10 (these lengths being measured in the direction designated by X10 in Figure 2) may be comprised between 1:1 (hence with the intermediate region 105 located approximately half way between the end 103 and the end 104 of the stent 10) and 2:1 (i.e., with the portion 10a approximately twice as long as the portion 10b) .

One or more embodiments may envisage facilitating the person who performs the operation of implantation in obtaining a proper positioning of the stent 10 with the portion 10a implanted in intra-ostial position, the portion 10b implanted in extra-ostial position, and the intermediate region 105 substantially aligned with the ostium itself.

As regards the materials that can be used for the production of a stent 10 as exemplified herein, the choice may fall on materials commonly used in the production of stents via techniques that envisage cutting (for example, via laser beam) starting from a micro-tube made of metal material, such as steel or L 605 or MP35 alloys.

A stent as exemplified herein may on the other hand be compatible with production using super-elastic materials, such as the alloy commonly referred to as nitinol .

Materials of this nature, as is nitinol, can also present shape-memory and/or self-expandability characteristics .

Consequently, a stent 10, as exemplified herein, may be suitable for being manufactured (also here according to criteria in themselves known to persons skilled in the sector) either as balloon-expandable stent or as self-expandable stent. In the first case, the stent 10 can be fitted on a balloon located at one end of an implantation catheter and then be made to advance towards the implantation site in a radially contracted condition (diameter D1 of the portion 10a) and then be expanded (radially expanded condition, with diameter D2) by inflating the balloon. The latter can then be deflated and withdrawn axially from the expanded stent with the possibility, exemplified schematically in Figure 3, of using the balloon B for shaping the portion 10b that projects on the outside of the ostium, for example for bestowing thereon an at least slightly widened and diverging (funnel-shaped) conformation, or else deflected sideways according to a periscope shape, on the basis of the implantation requirements.

In the case where recourse is had to a self- expandable stent solution, the stent 10 can be brought into the implantation site, keeping it in a radially contracted condition via a sheath that can then be withdrawn, enabling ( self-) expansion of the stent.

In the case where recourse is had to this solution, the effect of widening (and possibly of shaping of the extra-ostial portion 10b) can be achieved (according to criteria in themselves known) by exploiting a shape-memory mechanism.

It has been noted that recourse to a metal material, together with the "thick" nature of the wall (thickness d) , can bestow upon a stent 10 as exemplified herein a good degree of radio-opacity such as to enable the person performing the operation of implantation to position the stent 10 in the desired condition with the intermediate region 105 located at the ostium CO.

One or more embodiments may, however, envisage the presence of marking characteristics such as to enable identification of the position of the intermediate region 105.

For instance, Figure 4 exemplifies the possible application on the tubular body of the stent 10 (optionally in the intermediate region 105) of one or more markers 106 made of radio-opaque material: markers of this kind are used in stents of a conventional type (on the other hand, more often than not located in an end position of the stent itself, as the ones designated by 103a and 104a in Figure 4) .

In one or more embodiments, even without resorting to markers, such as the markers 106, 103a, 104a exemplified herein, the effect of marking (i.e., the possibility of identification of the position of the intermediate region 105) may result from the fact that the meshed structure (openwork structure) of the tubular body of the stent can present a variation in the intermediate region 105.

In this regard, it will be appreciated that Figure 4 is a representation of the stent 10 in an ideal plane development. In other words, in such a representation (widely used in the sector) the wall of the stent 10, having a tubular shape, is presented developed in the plane .

Figure 4 shows by way of example a stent 10 comprising a plurality of radially expandable annular segments 2, which have, for example, a sinusoidal-wave serpentine shape and are connected together by bridge elements 8, 8', which separate adjacent segments 2 and maintain the distance between these segments both in the radially contracted condition and in the radially expanded condition.

For instance, according to a solution described in some of the documents cited in the introductory part of the present description, each annular segment 2 may be obtained as a specular image of the adjacent annular segment or segments about a plane perpendicular to the longitudinal axis X10 of the stent. Hence, the peaks of one segment are longitudinally aligned with the troughs of an adjacent segment.

In one of the portions of the tubular body 10, for example in the portion 10a, the bridge elements 8 may comprise a concave portion, or else a U- or V-shaped portion having an apex 12. The U or V shape is joined to two connection arms that extend from the U or V shape (according to a general lambda configuration) and join up to adjacent sinusoidal segments 2 in a "zero point" of the sinusoidal waveform of each segment. The connection point is between a peak and a trough of each of the segments. In this way, radial expansion of the stent 10 can be rendered independent of any possible bending thereof in the longitudinal direction X10.

A similar criterion can be adopted for the other portion (for example, the portion 10b), with the difference that in this case the connection elements (or links) 8', albeit continuing to extend between zero points of the sinusoidal waveform of adjacent segments 2, do not present the lambda shape described previously, presenting, instead, a simple linear profile .

The corresponding variation of the meshed structure of the wall of the stent 10 (lambda-shaped elements 8 in the portion 10a and linear elements 8' in the portion 10b) constitutes a marking characteristic that can be observed in radioscopy thanks to the radio opacity of the material of the stent 10 and is hence able to guide the person performing the implantation operation, without necessarily having to envisage the presence of markers, such as the marker designated by 106 in Figure 4. It will on the other hand be appreciated that, in one or more embodiments, this variation of the meshed structure of the wall of the stent 10 may even be a local variation, limited to the intermediate region 105,

Another possible difference between the portions 10a and 10b, that can be used as marking characteristic for identifying the position of the intermediate region 105, may result from the fact that the meshed structure of the tubular body of the stent 10 is more "dense" in the portion 10a as compared to the portion 10b.

The above different geometry may on the other hand be linked to purposes other than the need to perform a marking function.

For instance, the fact that the meshed structure of the portion 10a is denser than that of the portion 10b may be dictated by the fact that the portion 10a, which is to extend within the coronary artery CA, is not in itself to be traversed by the blood flow: flow of the blood within the coronary artery occurs, in fact, through the axial lumen of the portion 10a, which pushes against the walls of the coronary artery so that the wall of the stent 10a is not in itself traversed by the blood flow (i.e., in the radial direction with respect to the axis X10) .

Instead, a less dense meshed structure of the portion 10b projecting within the aorta A facilitates the flow of blood, which, in this region, will flow both through the axial orifice of the stent 10 and in the radial direction through its wall, which is possibly shaped as exemplified on the right in Figure 3.

The meshed structure of the wall of the tubular body of the stent 10 results from the fact that the aforesaid wall of the tubular body comprises solid elements (the segments 2 and the connection elements 8, 8', commonly known as "struts") separated by apertures.

Whether the stent 10 is in a radially contracted condition or in the radially expanded condition, it is possible to define a surface void ratio, namely, a ratio between

- the area of wall of the stent occupied by the apertures between the struts (segments 2 and connection elements 8, 8') and

- the area of wall of the stent occupied by the struts themselves.

In one or more embodiments, with reference to the stent 10 expanded to a diameter of expansion comprised between 4.0 and 5.0 mm, the aforesaid ratio can range between 5.5 and 7 for the intra-ostial portion 10a and between 6.3 and 8.1 for the extra-ostial portion 10b.

In other words, in one or more embodiments, the meshed structure of the stent 10 may be denser (i.e., less apertured) in the portion 10a and less dense (i.e., more apertured) in the portion 10b.

This fact can be expressed in a way substantially independent of the diameter of expansion of the stent 10 by saying that the solid fraction of the portion 10a (i.e., the fraction of the unit surface of the stent 10 occupied by the struts 2, 8) has a value greater than the solid fraction of the portion 10a (i.e., the fraction of the unit surface of the stent 10 occupied by the struts 2, 8' ) ·

For instance, in one or more embodiments, the ratio between

- the value of the solid fraction in the portion 10a, i.e., the fraction of the unit surface of the stent 10 occupied by the struts 2, 8 in the portion 10a and

- the value of the solid fraction in the portion 10b, i.e., the fraction of unit surface of the stent lb occupied by the struts 2, 8' in the portion 10b

may be approximately equal to 1.19.

In one or more embodiments, it may be envisaged that the stent 10 presents characteristics of medicated stent (also commonly referred to as Drug Eluting Stent - DES) .

The above term identifies stents provided on which is an active agent that is to be transferred to the wall of the vessel in which the stent is implanted.

Among the most widely used active agents there may be cited agents that are to perform an antagonistic function of restenosis of the wall of the vessel. The mechanism of restenosis is put down to a mechanism of mechanical injury to the wall of the vessel such as to trigger a mechanism of growth of tissue that is liable to lead to gradual re-occlusion of the treated vessel. The corresponding literature (both the scientific literature and the patent literature) is extremely extensive .

Amongst the most widely used active agents there may, for example, be cited the agents known as rapamycin, FK506, or paclitaxel.

Irrespective of the specific choice of the active agent (an aspect that does not constitute a specific subject of the embodiments) one or more embodiments may envisage that the first portion 10a of the stent is the carrier of an effective amount of active agent (for example, rapamycin) which is to be released towards the wall of the coronary vessel CA, whereas the portion 10b is substantially without the aforesaid active agent, which, with the portion 10b projecting into the aorta, would be subject to a rapid flushing-off by the blood flow, thus dispersing in the circulatory system.

In the prior art, various solutions are known for possible loading of a stent with active agents of the above nature .

For instance, it is possible to coat the stent with a carrier (for example, a polymeric carrier) containing the active agent and designed to release the active agent itself gradually by dissolving.

One or more embodiments may, for this purpose, resort to the solution (which is also documented in some of the documents cited in the introductory part of the present description) that envisages formation, at least on the outer wall 102 of the stent 10 and in the intra-ostial portion 10a, of a surface patterning of the struts (2 and 8, for example) comprising furrows 14 that can function as reservoirs for loading an active agent that can be gradually released towards the wall of the vessel, against which the outer surface 102 of the stent is brought into contact as a result of expansion of the stent itself.

One or more embodiments may resort to the above solution in the portion 10a, which is to be implanted in the coronary vessel.

The presence of the aforesaid surface patterning (furrows or reservoirs 14) may present the further advantage of promoting a firm anchorage of the portion 10a, hence of the stent 10 as a whole, in the implantation site.

A coronary-ostium stent (for example, the stent 10) as exemplified herein, may comprise a tubular body with an inner surface (for example, 101) and an outer surface (for example, 102) having a wall thickness (for example d in Figure 3) between them, wherein:

- the tubular body extends in a longitudinal direction (for example, X10) between a first end (for example, 103) and a second end (for example, 104) opposite to one another and comprises a first, intra- ostial, portion (for example, 10a), from said first end (103) to an intermediate region (for example, 105) of the tubular body between said first and second ends, and a second, extra-ostial, portion (for example, 10b), from said intermediate region to said second end; and

- the first portion of the tubular body can be expanded from a radially contracted condition of insertion with a first diameter (for example, D1 in Figure 3) to a radially expanded condition of stenting of the ostium with a second diameter (for example, D2 in Figure 3) .

In a coronary-ostium stent as exemplified herein, the ratio between said wall thickness and said second diameter may be greater than 0.03 and, optionally, between 0.03 and 0.055.

In a coronary-ostium stent as exemplified herein, the ratio between the length of the first portion of the tubular body and the length of the second portion of the tubular body may be between 1 : 1 and 2:1.

A coronary-ostium stent as exemplified herein may comprise at least one marking characteristic (for example, a marker 106 and/or a variation of geometry 8, 8') in said intermediate region.

In a coronary-ostium stent as exemplified herein, the tubular body may comprise a meshed structure, and the at least one marking characteristic in said intermediate region may comprise a variation (for example, 8, 8') of said meshed structure in said intermediate region

In a coronary-ostium stent as exemplified herein, said first portion and said second portion may be provided and not provided, respectively, with an effective amount of releasable active agent.

In a coronary-ostium stent as exemplified herein, said first portion and said second portion may provided and not provided, respectively, with a surface patterning (for example, 14) .

In a coronary-ostium stent as exemplified herein, said surface patterning may comprise recesses provided at least on the outer surface of the tubular body, said recesses being filled with a releasable active agent.

In a coronary-ostium stent as exemplified herein, the tubular body may comprise a meshed structure formed by struts (for example, 2, 8 in the portion 10a and or 2, 8' in the portion 10b) having apertures between them, wherein:

- the ratio between the surface area of said struts in said first portion and the total surface area of said first portion has a first value;

- the ratio between the surface area of said struts in said second portion and the total surface area of said second portion has a second value; and

- said first value is higher than said second value, optionally with a ratio between said first value and said second value of approximately 1.19.

In a coronary-ostium stent as exemplified herein, the tubular body may comprise metal material.

In a coronary-ostium stent as exemplified herein, the tubular body may be of the balloon-expandable type (see, for example, B in Figure 3) .

Without prejudice to the underlying principles, the details of construction and the embodiments may vary, even significantly, with respect to what has been illustrated herein purely by way of non-limiting example, without thereby departing from the sphere of protection, as this is defined in the annexed claims.

Claims

1. A coronary ostium stent (10) comprising a tubular body having an inner surface (101) and an outer surface (102) with a wall thickness (d) therebetween, wherein :

- the tubular body extends in a longitudinal direction (X10) between opposed first (103) and second

(104) ends and comprises a first, intra-ostial portion (10a) from said first end (103) to an intermediate region (105) of the tubular body between said opposed first (103) and second (104) ends and a second, extra- ostial portion (10b) from said intermediate region

(105) to said second end (104),

- the first portion (10a) of the tubular body is expandable from a radially contracted insertion condition at a first diameter (Dl) towards a radially expanded ostium stenting condition at a second diameter (D2) .

2. The coronary ostium stent (10) of claim 1, wherein the ratio of said wall thickness (d) to said second diameter (D2) is in excess of 0.03, and preferably between 0.03 and 0.055.

3. The coronary ostium stent (10) of claim 1 or claim 2, wherein the ratio of the length of the first portion (10a) of the tubular body to the length of the second portion (10b) of the tubular body is from 1:1 to 2:1.

4. The coronary ostium stent (10) of any of the previous claims, comprising at least one marker feature (106; 8, 8') at said intermediate region (105) .

5 . The coronary ostium stent (10) of claim 4, wherein the tubular body comprises a reticular structure, wherein the at least one marker feature at said intermediate region (105) comprises a variation (8, 8') in said reticular structure at said intermediate region (105) .

6. The coronary ostium stent (10) of any of the previous claims, wherein said first portion (10a) and said second portion (10b) are provided with and exempt from, respectively, an effective amount of deliverable active agent.

7 . The coronary ostium stent (10) of any of the previous claims, wherein said first portion (10a) and said second portion (10b) are provided with and exempt from, respectively, surface sculpturing (14) .

8. The coronary ostium stent (10) of claim 6 and claim 7, wherein said surface sculpturing comprises recesses (14) provided at least at the outer surface (102) of the tubular body, said recesses having a filling of deliverable active agent.

9 . The coronary ostium stent (10) of any of the previous claims, wherein the tubular body comprises a reticular structure of struts (2, 8; 2, 8') having apertures therebetween, wherein:

- the ratio of the surface area of said struts (2, 8) in said first portion (10a) to the total surface area of said first portion (10a) has a first value,

- the ratio of the surface area of said struts (2, 8') in said second portion (10b) to the total surface area of said second portion (10b) has a second value, - said first value is higher than said second value, preferably with the ratio of said first value to said second value equal to about 1.19. 10 . The coronary ostium stent (10) of any of the previous claims, wherein the tubular body comprises metal material.

11 . The coronary ostium stent (10) of any of the previous claims, wherein the tubular body is of a balloon-expandable (B) type.