Surgical implant for marking soft tissue

Abstract

An implantable tissue marker device is provided to be placed in a soft tissue site through a surgical incision. The device can include a bioabsorbable body in the form of a spiral and defining a spheroid shape for the device, the spiral having a longitudinal axis, and turns of the spiral being spaced apart from each other in a direction along the longitudinal axis. A plurality of markers can be disposed on the body, the markers being visualizable by a radiographic imaging device. The turns of the spiral are sufficiently spaced apart to form gaps that allow soft tissue to infiltrate between the turns and to allow flexibility in the device along the longitudinal axis in the manner of a spring.

1 . An implantable fiducial tissue marker device to be placed in a soft tissue site through an open surgical incision, comprising:
 a bioabsorbable body formed whose outer regions define a peripheral boundary of the marker device   a plurality of visualization markers secured to the body so that visualization of the marker device using medical imaging equipment will indicate the location, of the tissue site;   wherein the implantable marker device is conformable to the adjacent soft tissue and whose peripheral boundary is able to be penetrated by adjacent soft tissue during its use.   
     
     
         2 . The device of  claim 1 , wherein the bioabsorbable body is in the shape of a spiral, the spiral having a longitudinal axis, and turns of the spiral being spaced apart from each other in a direction along the longitudinal axis. 
     
     
         3 . The device of  claim 3 , wherein the peripheral boundary of the device has a shape selected from the group consisting of spherical, scalene ellipsoid, prolate spheroid, and oblate spheroid shape. 
     
     
         4 . The device of  claim 3 , wherein the device has a north polar region and a south polar region at opposed ends of the longitudinal axis. 
     
     
         5 . The device of  claim 4 , wherein a strut is connected between the north polar region and the south polar region. 
     
     
         6 . The device of  claim 5 , wherein the strut includes a sliding element to allow the spiral body to be compressed in the manner of a spring. 
     
     
         7 . The device of  claim 4 , wherein visualization markers are attached to the body in the north polar region and/or the south polar region. 
     
     
         8 . The device of  claim 7 , wherein a plurality of visualization markers are attached to the body about an equatorial region of the substantially spheroid device. 
     
     
         9 . The device of  claim 8 , wherein at least four visualization markers are attached to the body about its equatorial region. 
     
     
         10 . The device of  claim 9 , wherein at least some of the visualization markers are radio-opaque clips. 
     
     
         11 . The device of  claim 10 , wherein the radio-opaque clips are attached to the body using preformed holes in the body into which the clips can be pressed and attached. 
     
     
         12 . A method for fabrication of a tissue marker device, comprising:
 using injection molding to form a body made of a bioabsorbable polymer in a planar configuration   heat forming the body so that the body is reconfigured from a planar configuration to a three dimensional configuration.   
     
     
         13 . The method of  claim 12 , further comprising forming pockets or through-holes in the body during injection molding and attaching visualization markers to the pockets or through-holes. 
     
     
         14 . The method of  claim 12 , wherein the injection molded body includes north and south polar regions, with each polar region including a polar extension that is directed toward an interior of the device. 
     
     
         15 . The method of  claim 14 , further comprising connecting a strut to the polar extensions. 
     
     
         16 . The method of  claim 15 , wherein the strut is slideably connected to at least one of the polar extensions. 
     
     
         17 . The method of  claim 12  whereby two or more separate parts are connected to achieve a finished product. 
     
     
         18 . An implantable tissue marker device to be placed in a soft tissue site through a surgical incision, comprising:
 a bioabsorbable body form of a spiral and defining a spheroid shape for the device, the spiral having a longitudinal axis, and turns of the spiral being spaced apart from each other in a direction along the longitudinal axis;   a plurality of markers disposed on the body, the markers being visualizable by a radiographic imaging device;   wherein the turns of the spiral are sufficiently spaced apart to form gaps that allow soft tissue to infiltrate between the turns and to allow flexibility in the device along the longitudinal axis in the manner of a spring.   
     
     
         19 . The device of  claim 18 , wherein the device has a spring constant in the direction of the longitudinal axis between about 5 and 50 grams per millimeter. 
     
     
         20 . The device of  claim 18 , wherein the bioabsorbable body includes opposed polar regions along the longitudinal axis. 
     
     
         21 . The device of  claim 20 , wherein markers are placed in each of the opposed polar regions. 
     
     
         22 . The device of  claim 21 , further including a plurality of markers placed along an equatorial region of the body. 
     
     
         23 . The device of  claim 22 , wherein at least four markers are placed along the equatorial region.