Stent with channel(s) for containing and delivering a biologically active material and method for manufacturing the same

#This invention relates generally to an implantable medical device for delivering biologically active materials. More specifically, the invention relates to an implantable stent prosthesis for delivering a biologically active material and a method for manufacturing the same. More particularly, the invention is directed to a stent having one or more channels for containing and delivering a biologically active material.

#Balloon angioplasty has been very effective in treating stenosis, i.e., to open blocked vessels and restore normal levels of blood flow. However, although once a blocked vessel is opened, the treated vessel has a tendency to restenose, i.e., reclose, shortly after the procedure. Thus, patients have to repeatedly be treated with angioplasty or surgery.

#Implantable stent prosthesis or stents are used to reduce restenosis after balloon angioplasty or other procedures using catheters. A stent in the form of a wire mesh tube props open an artery that has recently been cleared using angioplasty. The stent is collapsed to a small diameter, placed over an angioplasty balloon catheter and moved into the area of the blockage. When the balloon is inflated, the stent expands, locks in place and forms a scaffold to hold the artery open. Usually, the stent stays in the artery permanently, holds it open, improves blood flow to the heart muscle and relieves symptoms. The stent procedure is fairly common, and various types of stents have been developed and actually used.

#FIGS. 1A, 1B, 1C and 1D show embodiments of a stent with channel for containing a biologically active material where the stent covering material forms the channel wall defining the channel. FIG. 1A shows a cross-sectional view of such an embodiment. In the embodiment, an end of the outer (first) cover is folded to form the channel, i.e., the channel is formed between two layers of covering material. FIG. 1B depicts a cross-sectional view of another embodiment of the invention where a middle portion of the outer stent covering is used to form the channel wall. FIG. 1C depicts a cross-sectional view of an embodiment of the invention where an inner (second) covering is used to form the channel wall. FIG. 1D depicts a cross-sectional view of an embodiment of the invention which is similar to that of FIG. 1B. In FIG. 1B, the channel wall is formed by the outer cover in its entirety. On the other hand, the channel wall in FIG. 1D is formed by the outer cover in part and by the stent sidewall in part.

#FIG. 2 depicts a perspective view of another embodiment of a stent with a channel positioned along a circumference of the stent.

#FIGS. 3A and 3B illustrate perspective views of embodiments of a stent of the invention wherein a channel is woven with the struts or wires of a stent.

#An embodiment of the present invention is illustrated in FIG. 1A. FIG. 1A shows a stent 10 having a sidewall 16, made up of a plurality of struts 13. In the embodiment, an exterior surface of the stent sidewall 16 is covered with a first stent covering 12, and an interior luminal surface of the stent sidewall 16 is covered with a second stent covering 14. In this embodiment, the channel is formed by folding one end of the first stent covering 12 to form a channel 15. In this case, the channel wall 15a, which encompasses the space in the channel 15, is formed of the covering material. The term “channel” refers to a tube-like pocket along with the channel wall defining such pocket or space, i.e., the channel comprises both the channel wall and the pocket defined by the channel wall. In this embodiment, the channel 15 is positioned along the longitudinal axis of the stent. When the stent is introduced into a body lumen, the channel 15 contains biologically active material, and both ends of the channel 15 are preferably sealed.

#The stent 10 may be prepared by the following steps:

#(1) A stent is manufactured by a method known in the art and a stent covering 12 is disposed about the exterior surface of the stent sidewall 16.