Devices and methods for removing obstructions from a patient and methods for making obstruction removing devices

Abstract

The present invention provides an obstruction removing device and a method for making the obstruction removing device. The method includes two mandrels with an elongate element being wound around the first mandrel and then wrapped around the second mandrel. The mandrels are movable relative to one another so that the second mandrel may be moved closer to the first mandrel after winding the element around the first mandrel and before winding the element around the second mandrel.

1 . A method of forming an obstruction retrieving element, comprising the steps of: 
 providing a first mandrel and a second mandrel, at least one of the first and second mandrels being movable relative to the other mandrel so that the first and second mandrels are movable relative to one another between a first position and a second position, the first and second mandrels moving toward one another when moved from the first position to the second position;    wrapping an elongate element around the first mandrel with the first and second mandrels in the first position;    moving the at least one of the first and second mandrels to the second position after wrapping the elongate element around the first mandrel;    wrapping the elongate element around the second mandrel after the moving step.    
   
   
       2 . The method of  claim 1 , wherein: 
 the wrapping step is carried out with the elongate element intersecting a longitudinal axis of the mandrel.    
   
   
       3 . The method of  claim 1 , wherein: 
 the wrapping step is carried out with the elongate element being wrapped around the first mandrel so that the elongate element extends back toward a proximal end of the mandrel after intersecting the longitudinal axis.    
   
   
       4 . The method of  claim 1 , wherein: 
 the wrapping step is carried out with the elongate element being wrapped around the first mandrel to form at least one loop which extends around the longitudinal axis.    
   
   
       5 . The method of  claim 1 , wherein: 
 the moving step is carried out with the first and second mandrels each terminating at an end, the ends being moved toward one another during the moving step.    
   
   
       6 . The method of  claim 5 , wherein: 
 the wrapping step is carried out with the elongate element being wrapped over the end of the first mandrel; and    the moving step is carried out with the second mandrel being moved to a position which covers a portion of the elongate element which is wrapped over the end of the first mandrel.    
   
   
       7 . The method of  claim 6 , wherein: 
 the wrapping step is carried out with the end of the first mandrel having a convex shape with an apex, the elongate element being wrapped at least two times over the apex of the first mandrel before wrapping the elongate element around the second mandrel.    
   
   
       8 . A method for removing an obstruction from a cerebral vessel, comprising the steps of: 
 providing an obstruction removing device having an elongate element, the elongate element being movable from a collapsed position to an expanded position and being naturally biased toward the expanded position, the elongate element having a proximal section, a distal section and an intermediate section, the intermediate section being positioned between the distal and proximal sections, at least one of the proximal and distal sections forming at least two loops having a longitudinal axis, the intermediate section having a first crossing portion which intersects the longitudinal axis and a second crossing portion which also intersects the longitudinal axis;    introducing the obstruction removing device into a patient with the elongate element being in the collapsed position;    expanding the elongate element after the introducing step;    engaging an obstruction with the elongate element; and    removing the obstruction with the elongate element.    
   
   
       9 . The method of  claim 8 , wherein: 
 the providing step is carried out with the proximal section and the distal section both having at least two loops.    
   
   
       10 . The method of  claim 8 , wherein: 
 the providing step is carried out with the first and second crossing sections being substantially perpendicular to one another when viewed along the longitudinal axis.    
   
   
       11 . The method of  claim 8 , wherein: 
 the providing step is carried out with the at least two loops forming a circle when viewed along the longitudinal axis, the first and second crossing sections extending diametrically across the circle when viewed along the longitudinal axis.    
   
   
       12 . The method of  claim 8 , wherein: 
 the providing step is carried out with the first crossing portion having a part which extends in one direction and a part which extends in the other direction relative to the longitudinal axis.    
   
   
       13 . The method of  claim 12 , wherein: 
 the providing step is carried out with the first crossing portion changing direction when crossing the longitudinal axis.    
   
   
       14 . The method of  claim 8 , wherein: 
 the providing step is carried out with the at least one strand extending along the obstruction removing element when in the collapsed position.    
   
   
       15 . The method of  claim 14 , wherein: 
 the expanding step is carried out with strand extending between the proximal and distal sections dependent upon the permitted expansion of the obstruction removing element.    
   
   
       16 . The method of  claim 8 , wherein: 
 the providing step is carried out with the strand being coupled to the obstruction removing element at a proximal location and a distal location, wherein at least of the proximal and distal locations is slidable relative to the obstruction removing element.    
   
   
       17 . The method of  claim 16 , wherein: 
 the providing step is carried out with the at least one of the proximal and distal locations being slidable relative to the obstruction removing element in a manner dependent upon the permitted expansion of the obstruction removing element.    
   
   
       18 . The method of  claim 14 , wherein: 
 the expanding step is carried out with the element expanding in a helical motion so that the helical motion causes the strand to engage the element at a location dependent upon expansion of the element.    
   
   
       19 . The method of  claim 14 , wherein: 
 the expanding step is carried out with the element rotating as it emerges from the catheter, wherein rotation of the element causes the strand to become entangled with the element at locations dependent upon expansion of the element.    
   
   
       20 . The method of  claim 19 , wherein: 
 the expanding step is carried out with the strand being coupled to the element at a proximal location and a distal location, at least one of the proximal and distal locations being slidable relative to the obstruction removing element in a manner dependent upon the permitted expansion of the obstruction removing element.    
   
   
       21 . The method of  claim 14 , further comprising the step of: 
 manipulating the element to entangle the element with the strand and to entangle the element with the obstruction.    
   
   
       22 . The method of  claim 21 , wherein: 
 the manipulating step is carried out by pulling the elongate element, wherein the strand engages the element at the plurality of locations thereby reducing distortion of the element when the element is pulled.    
   
   
       23 . The method of  claim 14 , wherein: 
 the providing step is carried out with a plurality of strands coupled to the elongate element.    
   
   
       24 . The method of  claim 22 , wherein: 
 the manipulating step is carried out with the strand contacting the element at locations dependent upon permitted expansion of the element within the blood vessel.    
   
   
       25 . An obstruction retrieving element for removing obstructions from a vascular location, comprising: 
 a proximal section;    a distal section, at least one of the proximal and distal sections forming at least two loops having a longitudinal axis, and    an intermediate section positioned between and coupled to the distal and proximal sections, the intermediate section having a first crossing portion which intersects the longitudinal axis and a second crossing portion which also intersects the longitudinal axis.    
   
   
       26 . The device of  claim 25 , wherein: 
 the providing step is carried out with the proximal and distal sections both having at least two loops.    
   
   
       27 . The device of  claim 25 , wherein: 
 the first and second crossing sections are substantially perpendicular to one another when viewed along the longitudinal axis.    
   
   
       28 . The device of  claim 25 , wherein: 
 the at least two loops form a circle when viewed along the longitudinal axis, the first and second crossing sections extending diametrically across the circle when viewed along the longitudinal axis.    
   
   
       29 . The device of  claim 25 , wherein: 
 the first crossing portion has a part which extends generally in one direction and a part which extends generally in the other direction relative to the longitudinal axis.    
   
   
       30 . The device of  claim 29 , wherein: 
 the first crossing portion changes direction when intersecting the longitudinal axis.    
   
   
       31 . The device of  claim 25 , further comprising: 
 at least one strand extending along the elongate obstruction removing element when in the collapsed position.    
   
   
       32 . The device of  claim 25 , wherein: 
 the at least one strand is coupled to the element at a proximal location and a distal location.    
   
   
       33 . The device of  claim 32 , wherein: 
 the strand contacts the element at a plurality of locations when the element expands, the plurality of locations being dependent upon the permitted expansion of the element within the vessel.    
   
   
       34 . The device of  claim 33 , wherein: 
 the strand becomes naturally entangled with the element as the element expands.    
   
   
       35 . The device of  claim 33 , wherein: 
 the element has a rotary motion when expanding so that the strand naturally becomes entangled with the element.    
   
   
       36 . The device of  claim 32 , wherein: 
 at least one of the proximal and distal locations of the strand are slidable on the element.