Tissue harvesting device and method

Abstract

A tissue harvesting method and device for obtaining micrograft tissue particles within the size range of 50-1500 microns, and more preferably 500-1000 microns, and most preferably 600 microns. The particles may be processed after a piece of donor tissue has been excised from the donor site, or processed into the desired size directly at the donor site, and thereafter excised. Cutters having blades or cutting edges spaced in the range of 50-1500 microns are utilized to obtain particles within the desired size range. An elastomer is positioned between the cutting edges to push the excised particles out of the blades for ease of use.

What is claimed is:  
     
         1 . A method of harvesting tissue for transplantation to a recipient site, comprising the steps of: 
 (i) extracting a section of dermal tissue from a donor site;    (ii) processing said tissue through a tissue cutter such that said tissue is processed in to particles of a size conducive for cell proliferation greater than about 6:1 and up to about 20:1; and    (iii) mechanically retrieving said processed tissue from said cutter.    
     
     
         2 . The method of  claim 1  wherein said particles are within the size range of about 50 microns to 1500 microns.  
     
     
         3 . The method of  claim 1  wherein said particles are within the size range of about 500 microns to 1000 microns.  
     
     
         4 . The method of  claim 1  wherein said particles are within the size of about 600 microns.  
     
     
         5 . The method of  claim 1  wherein said cutter is comprised of a cylindrical roller having a raised surface of evenly spaced square shaped blades.  
     
     
         6 . The method of  claim 5  wherein said cutter is further comprised of a handle positioned axially along said cylindrical roller.  
     
     
         7 . The method of  claim 1  wherein said cutter is comprised of a die having a first plurality of raised edges and a second plurality of raised edges positioned perpendicular to said first plurality of raised edges.  
     
     
         8 . The method of  claim 7  wherein said die is pressed on said section of dermal tissue by means of an arbor.  
     
     
         9 . The method of  claim 7  wherein said die is manually pressed onto said section of dermal tissue.  
     
     
         10 . The method of  claim 7  wherein said die is pressed onto said section of dermal tissue from a proximal side of said tissue to a distal side of said tissue by means of a reciprocating roller.  
     
     
         11 . The method of  claim 7  wherein said die is concave, such that said raised edges are positioned on an outer curve of said concave die.  
     
     
         12 . The method of  claim 1  wherein said cutter is comprised of a first cylindrical roller positioned parallel to a second cylindrical roller, and wherein said first cylindrical roller is comprised of a first set of raised, parallel cutting edges, and wherein said second cylindrical roller is comprised of a second set of raised, parallel cutting edges, and wherein said first set of raised cutting edges is positioned approximately perpendicular to said second set of raised, parallel cutting edges.  
     
     
         13 . The method of  claim 12  wherein said first cylindrical roller cuts along a top face of said dermal tissue, and said second cylindrical roller cuts along a bottom face of said dermal tissue.  
     
     
         14 . The method of  claim 12  wherein said first and second cylindrical rollers cut along a single face of said dermal tissue.  
     
     
         15 . The method of  claim 1  wherein said cutter is comprised of a plurality of circular blades in parallel arrangement.  
     
     
         16 . The method of  claim 15  wherein said blades are adjustably secured so as to create a space between said blades, such that said space is within the range of about 50 microns to about 1500 microns.  
     
     
         17 . The method of  claim 15  wherein said blades are adjustably secured so as to create a space between said blades, such that said space is about 600 microns.  
     
     
         18 . The method of  claim 1  wherein said cutter is comprised of a plurality of microtomes.  
     
     
         19 . The method of  claim 1  wherein said cutter is comprised of a plurality of capillary tubes having a sharpened edge and arranged in a bundle.  
     
     
         20 . The method of  claim 1  wherein said step of mechanically retrieving said processed tissue from said cutter comprises positioning an elastomer between cutting surfaces of said cutter.  
     
     
         21 . A method of harvesting tissue for transplantation to a recipient site, comprising the steps of: 
 (i) applying a plurality of vertical cuts to a section of donor tissue at a donor site; and    (ii) extracting a plurality of donor particles from said donor site by applying a horizontal cut along a connection point of said donor particles to said donor site and through said vertical cuts, such that said donor particles are of a size conducive for proliferation greater than about 6:1 and up to about 20:1; and    
     
     
         22 . The method of  claim 21  wherein said extracting step is comprised of passing a dermatome across said vertical cuts.  
     
     
         23 . The method of  claim 21  wherein said size of said donor particles are within the range of about 50 microns to about 1500 microns.  
     
     
         24 . The method of  claim 21  wherein said size of said donor particles is within the range of about 300 microns to about 800 microns.  
     
     
         25 . The method of  claim 21  wherein said size of said donor particles is about 600 microns.  
     
     
         26 . The method of  claim 21  wherein said applying step is comprised of pressing a die having a plurality of perpendicularly arranged edges against said donor site.  
     
     
         27 . The method of  claim 26  wherein said extracting step is comprised of oscillating said die along a vertical axis.  
     
     
         28 . The method of  claim 21  wherein said applying step is comprised of pressing a rigid sheet having a plurality of opposing concave cutting edges.  
     
     
         29 . The method of  claim 28  wherein said extracting step is comprised of oscillating said rigid sheet along a vertical axis.  
     
     
         30 . A cutter for processing tissue into particles suitable for transplantation, comprised of a cylindrical roller having a raised surface of evenly spaced perpendicularly arranged cutting edges.  
     
     
         31 . The cutter of  claim 30  wherein said space between said cutting edges is between about 50 microns and about 1500 microns.  
     
     
         32 . The cutter of  claim 30  wherein said space between said cutting edges is about 600 microns.  
     
     
         33 . The cutter of  claim 30  further comprising a piezo-electric driver for oscillating cutter across the surface of tissue.  
     
     
         34 . A cutter for processing tissue into particles suitable for transplantation, comprised of a rigid sheet of raised cutting edges.  
     
     
         35 . The cutter of  claim 34  wherein said raised cutting edges form a grid having separations between said cutting edges between about 50 microns and about 1500 microns.  
     
     
         36 . The cutter of  claim 34  wherein said raised cutting edges form a grid having separations between said cutting edges of about 600 microns.  
     
     
         37 . The cutter of  claim 34  wherein said sheet is concave and said raised cutting edges project from an outer curve of said concave sheet.  
     
     
         38 . The cutter of  claim 34  wherein said raised cutting edges are comprised of a plurality of opposing concave cutting edges.  
     
     
         39 . The cutter of  claim 38  further comprising an oscillating driver connected to said cutter for oscillating said cutter across the surface of said tissue.  
     
     
         40 . A cutter for processing tissue into particles suitable for transplantation, comprising: 
 (i) a first cylindrical roller, having a first set of raised, parallel cutting edges; and    (ii) a second roller having a second set of raised, parallel cutting edges; and    (iii) wherein said first set of raised cutting edges is approximately perpendicular to said second set of raised cutting edges.    
     
     
         41 . The cutter of  claim 40  wherein said cutting edges are separated by between about 50 microns and 1500 microns.  
     
     
         42 . The cutter of  claim 40  wherein said cutting edges are separated by about 600 microns.  
     
     
         43 . A cutter for processing tissue into particles suitable for transplantation, comprising a plurality of circular blades in parallel arrangement along a horizontal axis, and wherein said blades are adjustably secured to create a uniform distance between each circular blade.  
     
     
         44 . The cutter of  claim 43  further comprising a handle positioned along said horizontal axis.  
     
     
         45 . The cutter of  claim 43  wherein said distance between each circular blade is between about 50 microns and 1500 microns.  
     
     
         46 . The cutter of  claim 43  wherein said distance between each circular blade is about 600 microns.  
     
     
         47 . A cutter for processing tissue into particles suitable for transplantation, comprising: 
 (i) a housing;    (ii) a cylindrical press movable within said housing from a closed distal end of said housing toward an open proximal end of said housing;    (iii) an elastomer fixedly connected to said press;    (iv) a removable cap positioned at said open proximal end of said housing; and    (v) a plurality of blades fixedly connected within said housing, and interposed between said press and said open proximal end.    
     
     
         48 . The cutter of  claim 47  wherein said blades are separated by a distance of between about 50 microns and 1500 microns.  
     
     
         49 . The cutter of  claim 47  wherein said blades are separated by a distance of about 600 microns.  
     
     
         50 . A cutter for processing tissue into particles suitable for transplantation, comprising: 
 (i) a plurality of serrated discs, wherein said discs are slotted, and wherein said discs are fixedly positioned along an axis such that a space is created between said discs for receiving a tissue sample;    (ii) a ring of longitudinal blades configured to pass between said serrations of said serrated discs.    
     
     
         51 . The cutter of  claim 50  further comprising a clamp for forcing said tissue into said cutter.