Radioactive medical suture and method of making the same

Abstract

A radioactive suture for inhibiting an intimal hyperplastic response comprises a needle and a suture material having a radioactive beta-emitting element. This radioactive element is preferably chemically bonded to an organic substrate of the suture material. It is preferred that the radioactive suture material generates a beta radiation greater than 0.0002 uCi/cm. A first preferred method for producing the radioactive suture comprises the steps of placing the suture needle and the suture material in a sealed reaction chamber. Once the suture is in the reaction chamber, an ionized beta radiation emitting element, preferably ionized tritium, is introduced into the chamber. While in the chamber, an entropic exchange process begins wherein the beta radiation emitting element is exchanged for hydrogen molecules in the organic suture material. Once the desired level of tritium or other beta radiation emitting element is incorporated in the suture material, the reaction chamber is flushed. The suture is then rinsed, dried, removed from the reaction chamber, and packaged. In another aspect, a radioactive suture may be fabricated from an organic polypropylene material. A beta radiation emitting element, preferably tritium, is incorporated directly into a backbone of the organic polypropylene material. The now radioactive polypropylene material is extruded into a suture thread, which is attached to a suture needle and packaged for shipment and later use. Although not required by the present inventive method, the preferred embodiment of the organic polypropylene material comprises carbon 12.