Indirect-release electrolytic implant delivery systems

Abstract

Medical devices and methods for delivery or implantation of prostheses within hollow body organs and vessels or other luminal anatomy are disclosed. The subject technologies may be used in the treatment of atherosclerosis in stenting procedures or be used in variety of other procedures. The systems may employ a self expanding stent restrained by one or more members released by an electrolytically erodable latch. Such release means do not connect directly to the implant, though one or more portions may contact it.

1 . A power supply for an implant delivery system employing at least one electrolytically erodable element, the improvement comprising: 
 adaptation of the power supply to provide an AC voltage profile with a peak-to-peak configuration of at least about 5V, and a DC voltage signal of at least about 1V.    
     
     
         2 . A method of implant delivery, the method comprising: 
 introducing an implant delivery system in an electrolytic fluid; and    applying electrical power to an electrolytically erodable member, the power AC voltage profile with a peak-to-peak configuration of at least about 5V, and a DC voltage signal of at least about 1V.    
     
     
         3 . A method of loading a self-expanding stent onto a delivery guide, the method comprising: 
 holding the stent compressed to a reduced diameter configuration in at least one sleeve;    engaging the stent with the delivery guide; and    twisting the stent while in the sleeve.    
     
     
         4 . The method of  claim 3 , further comprising compressing the stent before loading the stent into the at least one sleeve.  
     
     
         5 . The method of  claim 3 , wherein a plurality of sleeves hold the stent.  
     
     
         6 . The method of  claim 5 , wherein the stent is twisted by rotating one sleeve relative to another.  
     
     
         7 . The method of  claim 3 , further comprising removing the at least one sleeve from the stent.  
     
     
         8 . A stent delivery system comprising: 
 a delivery guide body having a distal portion and at least one elongate member including an electrolytically erodable section;    a stent comprising a near end, a far end and a structure extending therebetween,    at least one of the near and far end of the stent held in contact with the elongate body;    wherein release of the erodable section initiates stent release.    
     
     
         9 . The system of  claim 8 , wherein the stent is in a twisted configuration in contact with the elongate body.  
     
     
         10 . The system of  claim 8 , wherein at least one elongate member passes through the near or far end of the stent.  
     
     
         11 . The system of  claim 8 , wherein each electrolytically erodable section is spaced apart from the stent.  
     
     
         12 . The system of  claim 8 , wherein each elongate member defines a loop of material.  
     
     
         13 . The system of  claim 8 , wherein each end of the stent is capped.  
     
     
         14 . The system of  claim 8 , further comprising a slidably actuable tubular restraint over at least a portion of the stent.  
     
     
         15 . The system of  claim 14 , wherein only one of the near and far ends of the stent is held by an elongate member.  
     
     
         16 . The system of  claim 8 , wherein the delivery guide comprises near and far seats at the distal portion, and wherein the stent further comprises at least one of a near and a far mating portion at the near and far ends, respectively, each seat being adapted to receive a mating portion.  
     
     
         17 . The system of  claim 16 , wherein at least one elongate member is wrapped to at least partially cover each mating portion.  
     
     
         18 . The system of  claim 17 , wherein at least some of the mating portions and seats provide a keyed interface.  
     
     
         19 . The system of  claim 17 , wherein at least some of the mating portions and seats provide a slide-out interface.  
     
     
         20 . The system of  claim 16 , wherein the stent is in a twisted configuration in contact with the delivery guide body.  
     
     
         21 . The system of  20 , wherein each seat receives a mating portion, and wherein at least one seat is rotatable upon release of an electrolytically erodible section.  
     
     
         22 . The system of  claim 8 , wherein engagement of the at least one mating portion on one of the near and far ends of the stent is released by release of an electrolytically erodable member; and wherein engagement of the at least one mating portion on the other end of the stent occurs as a result of release of the same electrolytically erodable member.  
     
     
         23 . The system of  claim 22 , wherein movement of a floating cap releases the other end of the stent.  
     
     
         24 . The system of  claim 22 , wherein untwisting of a coil spring wound around a portion of the elongate body is released to retract and release the stent upon release of the electrolytically erodable member.  
     
     
         25 . The system of  claim 24 , wherein the spring retracts the seat upon release.  
     
     
         26 . The system of  claim 8 , wherein one end of the stent is released by relative sliding motion between the stent and the delivery guide body.  
     
     
         27 . The stent delivery system of  claim 26 , wherein the sliding release occurs as result of release of the electrolytically-released component.  
     
     
         28 . The stent delivery system of  claim 26 , wherein the sliding release occurs as result of advancing or withdrawing the delivery guide by a user.  
     
     
         29 . The system of  claim 28 , further comprising a catheter in which the delivery guide is received, an end of the catheter adapted to abut the near end of the stent upon release of the far end of the stent.  
     
     
         30 . The system of  claim 8 , further comprising a sleeve restraining the stent in a compressed state, wherein the sleeve is releasably secured by the erodable section.  
     
     
         31 . The system of  claim 30 , further comprising a spring positioned to actuate the sleeve.  
     
     
         32 . The system of  claim 31 , wherein the spring is a coil spring having a compressed, extended state and an expanded, retracted state.  
     
     
         33 . The system of  claim 32 , wherein retraction of the sleeve frees the stent to expand from the compressed state.  
     
     
         34 . The system of  claim 8 , wherein the erodable section is spaced apart from the stent.  
     
     
         35 . The system of  claim 8 , wherein any erodable section releases the stent directly.  
     
     
         36 . The system of  claim 8 , wherein any erodable section releases the stent indirectly.  
     
     
         37 . The system of  claim 8 , wherein any elongate member maintains the stent in a rotationally stable configuration for delivery.  
     
     
         38 . The system of  claim 37 , wherein any elongate member, alone, maintains the stent in a rotationally stable configuration for delivery.