Abstract: A method for making an intravascular stent by applying to the body of a stent a solution which includes a solvent, a polymer dissolved in the solvent and a therapeutic substance dispersed in the solvent and then evaporating the solvent. The inclusion of a polymer in intimate contact with a drug on the stent allows the drug to be retained on the stent during expansion of the stent and also controls the administration of drug following implantation. The adhesion of the coating and the rate at which the drug is delivered can be controlled by the selection of an appropriate bioabsorbable or biostable polymer and the ratio of drug to polymer in the solution. By this method, drugs such as dexamethasone can be applied to a stent, retained on a stent during expansion of the stent and elute at a controlled rate.

Abstract: A model of arterial restenosis in domestic pigs using deep injury to the coronary arterial media resulting in extensive proliferative response. Metal wire coils are delivered percutaneously to the coronary arteries of pigs with an oversized, high pressure (14 atm) balloon and left in place for 5-6 weeks. During placement, the balloon expands the coils and delivers them securely within the arterial lumen causing fracture of the internal elastic lamina by the coil. An extensive proliferative response occurs and is associated with a lumenal area narrowing of at least 50% Immunohistochemical studies confirms the prominence of smooth muscle cells in the tissue. The histopathologic features of the proliferative response are identical to those observed in cases of restenosis post-angioplasty.This model closely mimics the proliferative portion of human restenosis both grossly and microscopically.

Abstract: A temporary stent catheter and method for use. The catheter is particularly useful for restoring patency to an artery following a Percutaneous Transluminal Coronary Angioplasty (PTCA) procedure. The catheter comprises a catheter tube having a distal end and a proximal end; an elongated balloon inflatable by fluid pressure attached to the catheter tube near its distal end; a stent having a generally tubular configuration attached to the catheter tube near its distal end and surrounding the balloon; a pressurization device near the proximal end of the catheter tube for inflating and deflating the balloon whereby the stent may be pressed against the wall of a blood vessel by the balloon and the balloon may be subsequently deflated to permit blood flow through the expanded stent; and a restriction device near the proximal end of the catheter tube for maintaining the stent in an expanded condition and for subsequently effecting the radial contraction of the stent whereby it may be removed from the blood vessel.

Abstract: In a first embodiment a number of stent segments are connected together by hinges welded in place to provide articulation between the stent segments. The hinges can be, among other shapes, either a straight wire or a coiled wire of biocompatable material. A second embodiment uses a stent of a previous invention made up of a number or wires welded together for the stent segments with connection between adjacent stents provided by having one of the wires of adjacent stents continue between these adjacent stents to provide a hinge action. In this embodiment the wire portion extending between the segments is ground to a smaller diameter than the wire of the stent segment itself, to provide the necessary hinge flexibility. This articulated stent, made up of a number of individual stent segments, gives support for curved arteries, with the hinges between the segments providing both articulation and spacing between the stent segments.

Abstract: A cylindrical shaped stent to prevent arterial acute closure and subsequent restenosis formed of longitudinal wires of biocompatible metal. The wires are welded together in pairs at alternate ends with each pair of wires bent into a V-section. The wires are all formed into a cylinder welded closed to form the stent. The stent is compressed and loaded into an outer catheter by a special tool. The stent is positioned and released for self expansion in situ by an inner catheter. A guide wire through both assists in threading the catheters through blood vessels.