Device with a prosthesis implantable in the body of a patient

Abstract

The device comprises a prosthesis designed as a hollow body compressed against the action of restoring spring forces to a cross section reduced relative to an expanded use position, and held in this position by a strippable sheath. After the sheath is stripped, the prosthesis automatically expands to a cross section corresponding to the use position. The sheath, which can be a meshwork in the approximate form of crocheted material, extends over the entire length of the prosthesis and consists of at least one continuous thread and at least one drawstring. The prosthesis, held in the radially compressed position by the sheath, can be mounted displaceably on a feed wire or non-axially-displaceably on the insertion end of a probe or a catheter.

I claim:  
     
       1. In combination, a device with a prosthesis implantable in a body of a patient, said prosthesis designed as a hollow body and being compressible against restoring spring forces to a cross section which is reduced relative to an expanded use position, said prosthesis also, after removal of restraining forces that maintain said prosthesis in reduced cross section, expanding automatically to a cross section that corresponds to the use position, wherein said device is a strippable sheath formed of at least one continuous thread surrounding said prosthesis in said reduced cross section, and at least one drawstring being layable to extend from the sheath that holds the prosthesis in reduced cross section, said drawstring being retractable to effect automatic expansion of said prosthesis by removing said sheath. 
     
     
       2. The device according to  claim 1  wherein the sheath holding the prosthesis in reduced cross section is a strippable meshwork. 
     
     
       3. The device according to  claim 1  wherein the prosthesis, held in reduced cross section by the strippable sheath, is mounted on a probe advanceable into a body lumen. 
     
     
       4. The device according to  claim 3  wherein said probe is an elongate catheter with a distal insertion end for entry into a body lumen and a proximal end, said prosthesis, held in reduced cross section by the strippable sheath, being held in an axially fixed manner on the insertion end of said probe. 
     
     
       5. The device according to  claim 4  wherein the probe for advancing the prosthesis includes a lumen so the probe can be advanced over a guide wire. 
     
     
       6. The device according to  claim 3  wherein the prosthesis is mounted on a nonslip substrate which is mounted on the probe. 
     
     
       7. The device according to  claim 3  wherein a first end of the thread forming the sheath and a second end of the thread forming an end loop of the sheath are secured at positions on the probe and releasable by pulling the drawstring. 
     
     
       8. The device according to  claim 7  wherein the first and second ends of the thread forming the sheath are pinched in holes of the probe. 
     
     
       9. The device according to  claim 7  wherein the first end of the thread forming the sheath is pinched between the probe and an elastic cuff. 
     
     
       10. The device according to  claim 7 including a sheath with anwherein the end loop is attached to the probe and onethe second end of the thread forming said end loop extendingextends from a slipknot to form said drawstring. 
     
     
       11. The device according to  claim 3  wherein the prosthesis is held in its radially compressed position by means of a  sheath of  includes a first strippable meshwork applied from the distal end of the probe and a second strippable meshwork applied in the opposite [axial] direction thereto,  from the proximal end,   of the probe  and extending over an end loop of the first meshwork. 
     
     
       12. The device according to  claim 11  wherein said meshworks are strippable in opposite axial directions by drawstrings. 
     
     
       13. The device according to  claim 3  wherein at least one end of the prosthesis is surrounded in the compressed state by a cuff on the probe, said prosthesis escaping from the cuff as a result of axial shortening that takes place during the expansion of the prosthesis. 
     
     
       14. The device according to  claim 3  wherein an end of the prosthesis facing away from the  an insertion end of the probe abuts a radial projection on the probe. 
     
     
       15. The device according to  claim 3  wherein the drawstring is fed through a lumen in the probe and through a hole in the probe lumen that passes through a probe wall in the vicinity of one end of the prosthesis, said lumen extending to the proximal end of the probe. 
     
     
       16. The device according to  claim 15  wherein the probe is a double-lumen catheter, with one lumen being used to advance the catheter over a guide wire and the drawstring for the meshwork surrounding the prosthesis being passed through the other lumen. 
     
     
       17. The device according to claim  1   52 wherein the prosthesis is a mesh tube including metal thread material. 
     
     
       18. The device according to  claim 17  wherein the prosthesis has successive mesh rows alternately made of resorbable and nonresorbable thread material. 
     
     
       19. The device according to  claim 18  wherein drugs are embedded in the resorbable thread material for enabling drug deposit by said prosthesis. 
     
     
       20. The device according to  claim 18  or  19  wherein said non-resorbable material is a metal. 
     
     
       21. The device according to  claim 19  wherein the sheath has successive mesh loops formed in opposite circumferential directions around the prosthesis, so that when successive mesh loops are stripped, the thread segments forming the loops come loose alternately on the right and left from the prosthesis. 
     
     
       22. The device according to any one of claims  1   52 ,  2 ,  3 ,  5 , or  17  wherein the sheath has successive mesh loops formed in opposite circumferential directions around the prosthesis, so that when successive mesh loops are stripped, the thread segments forming the loops come loose alternately on the right and left from the prosthesis. 
     
     
       23. The device according to  claim 22  wherein the sheath surrounding the strippable tube  prosthesis is formed of a patterned thread material. 
     
     
       24. The device according to  claim 22  wherein the sheath surrounding the prosthesis is a strippable tube manufactured by crocheting. 
     
     
       25. The device according to  claim 24  wherein knots of said strippable loops of the surrounding sheath are arranged so that adjacent knots lie respectively on opposite sides of the sheath. 
     
     
       26. The device according to  claim 24 or  25   wherein knots of said strippable loops of the surrounding sheath are arranged such that alternate knots lie axially sequentially in rows. 
     
     
       27. The device according to any one of claims  1   52 ,  2 ,  3 ,  5 , or  17  wherein the drawstring extends from a portion of the sheath surrounding a distal insertion end of the prosthesis so that when the sheath is stripped, the prosthesis gradually expands from the distal end to the proximal end. 
     
     
       28. The device according to claim  1   52 wherein an end of the thread forming the sheath is held by a strippable slipknot. 
     
     
       29. The device according to any one of claims  1   52 ,  3 , or  17  wherein the sheath holding the prosthesis in its radially compressed position is formed of successive wrapping loops wrapped around the prosthesis at axial distances from one another, said wrapping loops being of a thread material extending along the inside of the prosthesis and pulled through a first hole in the prosthesis, the ends of said wrapping loops being guided back through a second hole in said prosthesis circumferentially adjacent to the first hole, and into the interior of the prosthesis, and said device further including a warp thread, running along the inside of the prosthesis and guided through the ends of the loops, the warp thread holding the loops in their wrapped positions. 
     
     
       30. The device according to any one of claims  1   52 ,  3 , or  17  wherein the sheath holding the prosthesis in its radially compressed position is formed of wrapping loops wrapped around the prosthesis at axial distances from one another, said wrapping loops being of a thread material extending along the inside of the prosthesis and pulled through a first hole in the prosthesis, ends of said loops guided back into the interior of the prosthesis through a second hole spaced axially from the first hole, the wrapping loops being held in wrapping position by a loop formed from the thread material running inside the prosthesis being pulled through the end of the wrapping loop positioned inside the prosthesis, said loop passing through the end of the wrapping loop then extending outward through an adjacent hole in the axial direction and being wrapped around the prosthesis to form an adjacent wrapping loop. 
     
     
       31. The device according to claim  1   52 or  17  wherein the sheath is formed of shrinkable thread material. 
     
     
       32. The device according to claim  1   52 or  17  wherein the strippable sheath is  includes a plurality of threads running parallel to one another. 
     
     
       33. The device according to claim  1   52 or  17  wherein at least two sheaths are provided wherein a first one of the two sheaths holds the prosthesis in the radially compressed state and a second sheath fits loosely around the prosthesis such that when the first sheath is stripped, the second sheath permits partial expansion of the prosthesis, said second sheath being subsequently strippable itself to permit full expansion. 
     
     
       34. The device according to claim  1   52 wherein the sheath is a meshwork surrounding the prosthesis with spaces between meshes filled and smoothed with a substance that dissolves in the body of a patient. 
     
     
       35. The device according to claim  1   52 wherein the thread material  forming the sheath is provided with a lubricant to reduce friction. 
     
     
       36. The device according to claim  1   52 wherein at least the drawstring is constructed with metal so that it is visible in an x-ray image. 
     
     
       37. The device according to claim  1   52 wherein the proximal end of the prosthesis is flared in the expanded state, following removal of the sheath. 
     
     
       38. The device according to claim  1   52 or  17  wherein said prosthesis is formed by a patterned thread material. 
     
     
       39. The device according to claim  1   52 or  17  wherein said prosthesis is a knitted mesh tube. 
     
     
       40. The device according to claim  1   52 or  17  wherein said prosthesis is a crocheted mesh tube. 
     
     
       41. The device according to claim  1   52 wherein said prosthesis is a mesh tube composed of plastic thread material. 
     
     
       42. The device of claim  1   52 or  35  wherein the thread forming said sheath is provided with a lubricant. 
     
     
       43. A system for implanting a prosthesis at a desired location in a body lumen, comprising: 
       a catheter constructed for percutaneous delivery, including a distal portion for receiving and carrying said prosthesis to said location, and a prosthesis release control mesh formed of a thread-like strand and surrounding said prosthesis for substantially its entire length, said release-control mesh being capable of maintaining said prosthesis on said catheter and said release control mesh further capable of being controllably unraveled from one end to the other by pulling an end of said thread-like strand to release said prosthesis from said catheter and allow it to be expanded into engagement with said body lumen at said desired site.  
     
     
       44. The system of  claim 43  wherein said release-control mesh is a mesh of the type formed by forming a first loop over said wrapped portion  that extends over one end of said prosthesis, a free end of said thread being formed into a second loop which is wrapped around said prosthesis and through said first loop, and the process being repeated to form additional loops which are wrapped about said prosthesis until the entire length of said prosthesis has been wrapped and said mesh terminates in an end loop. 
     
     
       45. The system of  claim 43  wherein a free end of said thread from said  forms an end loop and extends to the proximal end of said catheter, whereby pulling said thread will release  removes said end loop from said catheter  free end of thread and continued pulling will unravel  unravels said mesh from one end to the other releasing said prosthesis from one end to another. 
     
     
       46. The system of  claim 45  wherein the end loop of said mesh is releasably secured to said catheter. 
     
     
       47. The system of  claim 46  wherein said end loop is releasably secured by an elastic sleeve attached to said catheter. 
     
     
       48. The system of claim  47   44 wherein the first loop is releasably secured to said catheter by an elastic sleeve attached to said catheter. 
     
     
       49. The system of  claim 45  wherein said free end of said thread extends through a lumen in said catheter to said proximal end. 
     
     
       50. The system of any one of claims  43 - 49  wherein said mesh unravels from the distal end to the proximal end. 
     
     
       51. The system of any one of claims  43 - 49  wherein said prosthesis is a self-expanding prosthesis of the type that expands under spring force. 
     
     
       52. In combination, a device with a prosthesis implantable in a body of a patient, said prosthesis designed as a hollow body and being compressible against restoring spring forces to a cross section which is reduced relative to an expanded use position, said prosthesis also, after removal of restraining forces that maintain said prosthesis in reduced cross section, expanding automatically to a cross section that corresponds to the use position, wherein said device comprises at least one strippable sheath formed of at least one continuous thread surrounding said prosthesis in said reduced cross section, and at least one drawstring extending from the sheath that holds the prosthesis in reduced cross section, said drawstring being retractable to effect automatic expansion of said prosthesis by removing said sheath.