Radiopaque surgical implement

Abstract

X-ray imageable articles, for instance surgical implements or parts therefore which are used in minimally invasive surgical procedures, may be prepared by a process including the steps of: (a) preparing a mixture composition comprising: i) radiolucent particulate material selected from ceramic materials, metallurgic materials, and combinations thereof and having a particulate size of no more than 40 microns, ii) radiopaque particulate material selected from ceramic materials, metallurgic materials, and combinations thereof and having a particulate size of no more than 40 microns, and (iii) at least one polymeric binder material; (b) injection molding the mixture composition into a preform; (c) optionally removing the binder material from the preform; and (d) sintering the preform.

1 . A method for preparing an X-ray imageable article comprising: 
 (a) preparing a mixture composition comprising: 
 i) radiolucent particulate material selected from ceramic materials, metallurgic materials, and combinations thereof and having an average particulate size of no more than  40  microns,  
 ii) radiopaque particulate material selected from ceramic materials, metallurgic materials, and combinations thereof and having an average particulate size of no more than  40  microns, and  
 (iii) at least one polymeric binder material;  
   (b) injection molding the mixture composition into a preform;    (c) optionally removing the binder material from the preform; and    (d) sintering the preform.    
     
     
         2 . A method as in  claim 1  wherein said article is a surgical implement or component thereof, said implement adapted to be disposed on a catheter and conveyed thereon a remote site within the body and operated at such site to perform a surgical procedure.  
     
     
         3 . A method as in  claim 1  wherein said radiolucent material is selected from the group consisting of alumina, aluminum nitride, silica, silicon, silicon carbide, silicon nitride, sialon, zirconia, zirconium nitride, zirconium carbide, zirconium boride, titania, titanium nitride, titanium carbide, barium titanate, titanium boride, boron nitride, boron carbide, magnesium oxide, calcium oxide, stainless steel, iron, nickel, titanium, nitinol, and metallic oxides which can be converted to metals when sintered in a reducing environment, and combinations thereof.  
     
     
         4 . A method as in  claim 1  wherein said radiopaque material is selected from the group consisting of tungsten carbide, tungsten boride, the metals platinum, tantalum, iridium, tungsten, rhenium and gold, alloys of said metals, and combinations thereof.  
     
     
         5 . A method as in  claim 1  wherein the radiopaque material (ii) constitutes at least 2% and no more than about 75% by volume of the total volume of the components (i) and (ii).  
     
     
         6 . A method as in  claim 1  wherein the radiolucent material is selected from the group consisting of alumina, zirconia and stainless steel and the radiopaque material is selected from the group consisting of platinum, tungsten, rhenium and tantalum, and the radiopaque material constitutes from about 10 to about 50% by volume of the total volume of the components (i) and (ii).  
     
     
         7 . A method as in  claim 1  wherein the binder component (iii) is selected from the group consisting of polyolefins; olefin copolymers such as ethylene vinyl acetate copolymers; poly(meth)acrylates; styrene group resins; polyvinyl chloride; polyamides; polyesters; polyethers; polyacetals; and waxes.  
     
     
         8 . A method as in  claim 1  wherein the binder component (iii) is employed in said mixture composition in an amount of from about 2% to about 30% by weight thereof.  
     
     
         9 . A method as in  claim 1  wherein the binder removal step c) is preformed.  
     
     
         10 . An article comprising a sintered mixture of at least two inorganic powder materials at least one of which is a radiolucent and at least one of which is radiopaque.  
     
     
         11 . A medical device comprising an article as in  claim 10 .  
     
     
         12 . A medical device as in  claim 11  wherein said device comprises a catheter and said article is a surgical implement which can be carried on the catheter to a remote site within the body.  
     
     
         13 . A medical device as in  claim 12  wherein said radiolucent material is selected from the group consisting of alumina, aluminum nitride, silica, silicon, silicon carbide, silicon nitride, sialon, zirconia, zirconium nitride, zirconium carbide, zirconium boride, titania, titanium nitride, titanium carbide, barium titanate, titanium boride, boron nitride, boron carbide, magnesium oxide, calcium oxide, stainless steel, iron, nickel, titanium, nitinol, and metallic oxides which can be converted to metals when sintered in a reducing environment, and combinations thereof.  
     
     
         14 . A medical device as in  claim 12  wherein said radiopaque material is selected from the group consisting of tungsten carbide, tungsten boride, the metals platinum, tantalum, iridium, tungsten, rhenium and gold, alloys of said metals, and combinations thereof.  
     
     
         15 . A medical device as in  claim 12  wherein the radiopaque material constitutes at least 2% and no more than about 75% by volume of the total volume of the radiolucent and the radiopaque materials.  
     
     
         16 . A medical device as in  claim 12  wherein the radiolucent material is selected from the group consisting of alumina, zirconia and stainless steel and the radiopaque material is selected from the group consisting of platinum, tungsten, rhenium and tantalum, and the radiopaque material constitutes from about 10 to about 50% by volume of the total volume of the radiolucent and the radiopaque materials.  
     
     
         17 . A composition useful for preparing radiopaque components of a medical device structure, the composition comprising a mixture of 
 i) radiolucent particulate material selected from ceramic materials, metallurgic materials, and combinations thereof and having an average particulate size of no more than 40 microns,    ii) radiopaque particulate material selected from ceramic materials, metallurgic materials, and combinations thereof and having an average particulate size of no more than  40  microns, and    (iii) at least one polymeric binder material.    
     
     
         18 . A composition as in  claim 17  wherein: 
 the radiolucent material is selected from the group consisting of alumina, aluminum nitride, silica, silicon, silicon carbide, silicon nitride, sialon, zirconia, zirconium nitride, zirconium carbide, zirconium boride, titania, titanium nitride, titanium carbide, barium titanate, titanium boride, boron nitride, boron carbide, magnesium oxide, calcium oxide, stainless steel, iron, nickel, titanium, nitinol, and metallic oxides which can be converted to metals when sintered in a reducing environment, and combinations thereof;  
 the radiopaque material is selected from the group consisting of tungsten carbide, tungsten boride, the metals platinum, tantalum, iridium, tungsten, rhenium and gold, alloys of said metals, and combinations thereof;  
 the radiopaque material constitutes at least 2% and no more than about 75% by volume of the total volume of the radiolucent and the radiopaque materials; and. the binder material is present in said composition in an amount of from about 2% to about 30% by weight thereof.  
 
     
     
         19 . A composition as in  claim 17  wherein the radiolucent material is selected from the group consisting of alumina, zirconia and stainless steel and the radiopaque material is selected from the group consisting of platinum, tungsten, rhenium and tantalum, and the radiopaque material constitutes from about 10 to about 50% by volume of the total volume of the radiolucent and the radiopaque materials.  
     
     
         20 . A composition as in  claim 17  wherein the average particle sizes of the radiolucent and radiopaque materials are from about 0.5 to about 10 micrometers.  
     
     
         21 . A composition as in  claim 17  wherein the radiopaque material has a melting point which is greater than or equal to the melting point of the radiolucent material.  
     
     
         22 . A surgical method comprising conveying a surgical implement via a catheter to a remote site within the body, using said implement to perform a surgical procedure at said site and observing the implement fluoroscopically during at least a portion of the time it is in the body, wherein the implement comprises an article as in  claim 10 .  
     
     
         23 . A surgical method as in  claim 22  wherein the radiolucent and the radiopaque powder materials are present in relative amounts which renders the article bright enough during X-ray fluoroscopy to be seen using an X-ray intensity which allows visualization of the surrounding tissue, but dim enough to be seen through.  
     
     
         24 . A method as in  claim 2  wherein the radiolucent and the radiopaque powder materials are present in relative amounts which renders the article, when in the body, bright enough during X-ray fluoroscopy to be seen using an X-ray intensity which allows visualization of the surrounding tissue, but dim enough to be seen through.  
     
     
         25  A medical device as in  claim 12  wherein the radiolucent and the radiopaque powder materials are present in relative amounts which renders the article, when in the body, bright enough during X-ray fluoroscopy to be seen using an X-ray intensity which allows visualization of the surrounding tissue, but dim enough to be seen through.