Minimally invasive medical device deployment and retrieval system

Abstract

The present invention provides a medical device retrieval system comprising a working element carried by a flexible, elongate shaft, the working element having a proximal profile and the shaft extending proximally from the working element and a retrieval cover slidably carried along the shaft of the medical device, the cover having a deployed configuration and being capable of being compressed into a compressed configuration for deployment, yet resiliendy substantially return to the deployed configuration; the cover in its deployed configuration having a radially reduced proximal portion, a distally open distal end defining a distal opening having a maximum dimension at least as great as the maximum dimension of the proximal profile of the working element of the medical device, and an elongate internal recess defined between the proximal portion and the distal end.

What is claimed is:  
     
         1 . A medical device retrieval system, comprising: 
 a) a medical device comprising a working element carried by a flexible, elongate shaft, the working element having a proximal profile and the shaft extending proximally from the working element; and    b) a retrieval cover slidably carried along the shaft of the medical device, the cover having a deployed configuration and being capable of being compressed into a compressed configuration for deployment, yet resiliently substantially return to the deployed configuration; the cover in its deployed configuration having a radially reduced proximal portion, a distally open distal end defining a distal opening having a maximum dimension at least as great as the maximum dimension of the proximal profile of the working element of the medical device, and an elongate internal recess defined between the proximal portion and the distal end; the cover in its compressed configuration being radially compressed inwardly toward the shaft and being distally open with the distal end defining the distal-most portion of the cover.    
     
     
         2 . The system of  claim 1  further comprising a retrieval sheath, the retrieval sheath being slidable along the shaft of the medical device and being positioned distally of the cover when the cover is in its deployed configuration.  
     
     
         3 . The system of  claim 2  where in the retrieval sheath has an inner diameter smaller than an outer diameter of the cover in its deployed configuration, the sheath being adapted to slide distally along the cover to compress the cover about the medical device.  
     
     
         4 . The system of  claim 2  wherein the retrieval sheath has a body and a distal tip comprising a distal length of the retrieval sheath, the distal tip being bent at an angle of between about 5 and about 30° with respect to the body.  
     
     
         5 . The system of  claim 4  wherein the distal tip is between about 1 cm and about 5 cm in length.  
     
     
         6 . The system of  claim 4  wherein the distal tip further comprises a radiopaque marker band.  
     
     
         7 . A medical device retrieval system, comprising: 
 a) a medical device comprising a working element carried by a flexible, elongate shaft having an outer diameter, the working element having a proximal profile and the shaft extending proximally from the working element;    b) a retrieval sheath being slidable along the shaft of the medical device, the retrieval sheath having a beveled distal end with a distal lumen;    c) a deployment stylet slidable along the shaft of the medical device, the deployment stylet having a distal tip tapering distally from a first diameter approximating a diameter of the distal lumen of the sheath to a second diameter more closely approximating the outer diameter of the medical device shaft, providing a transition between the shaft of the medical device and the distal end of the retrieval sheath when the deployment stylet is positioned such that the distal tip extends distally beyond the distal end of the retrieval sheath; and    d) a retrieval cover slidable along the shaft of the medical device and being exchangeable for the stylet therealong, the cover having a deployed configuration and being capable of being compressed into a compressed configuration for siding within the lumen of the retrieval sheath yet resiliently substantially return to the deployed configuration; the cover in its deployed configuration having a radially reduced proximal portion, a distally open distal end defining a distal opening having a maximum dimension at least as great as the maximum dimension of the proximal profile of the working element of the medical device, and an elongate internal recess defined between the proximal portion and the distal end; the cover in its compressed configuration being radially compressed inwardly toward the shaft and being distally open with the distal end defining the distal-most portion of the cover.    
     
     
         8 . A retractable medical device system, comprising: 
 a) a medical device comprising a working element carried by a flexible, elongate shaft;    b) a retrieval cover slidable along the shaft of the medical device, the cover having a radially reduced proximal portion, a distally open distal end and an elongate tubular wall extending therebetween and defining a recess; the working element of the medical device being completely retained within the recess of the cover such that the tubular wall extends distally beyond the medical device; and    c) a retrieval sheath, the retrieval sheath having a lumen and being slidable with respect to both the medical device and the cover, at least a proximal length of the working element of the medical device and the cover being retained within the lumen of the retrieval sheath, the retrieval sheath radially compressing the proximal, length of the cover such that an intermediate portion of the wall tightly engages a surface of the medical device.    
     
     
         9 . A method of retrieving particulate or other foreign material within a channel of a patient's body, comprising: 
 a) providing a medical device having a working element and a flexible, elongate shaft adapted to follow a path within the channel; a distally open cover slidable with respect to the shaft; and a retrieval sheath moveable with respect to the cover and the shaft;    b) positioning the medical device within the vessel to engage a wall of the channel and trap the material within the channel, the cover and the retrieval sheath being spaced proximally of the working element along the shaft of the medical device, the cover being radially compressed within the lumen of the retrieval sheath such that it has a distally open distal end and a wall defining a recess, the wall engaging an inner surface of the retrieval sheath;    c) moving the cover distally with respect to the retrieval sheath, thereby permitting the cover to radially expand into a deployed configuration wherein the distal end remains distally open and the endosure is radially expanded, the cover expanding radially outwardly into the deployed configuration without having to invert on itself;    d) moving the cover distally with respect to the medical device and into engagement with a surface of the medical device to form therebetween an enclosure;    e) moving the retrieval sheath distally with respect to the cover to urge the cover to collapse about the medical device and tightly engage the surface of the medical device.