Snare mechanism for surgical retrieval
A snare device for capturing an object or for cutting tissue in the body of a human or animal. The device employs at least one twisted loop of memory shaped material housed in and movable relative to a hollow member such as a catheter. The device and method of employment is particularly well adapted for retrieving objects from internal body cavities and cutting tissue therein.
1. A snare device for capturing an object, comprising:
a wire of memory shaped material shaped to define at least a first loop in a first plane and a second loop in a second plane so as to define a first region between said first and second loops, said wire being movable relative to a hollow member such that said first and second loops are deployable from and retractable into said hollow member; and
a locking wire translatable through at least one of said first and second loops after an object is encircled or enveloped by said first and second loops, so as to capture said object within said first region;
wherein:
said first region tightens around said object as said first and second loops are retracted into said hollow member; and
when said wire of memory shaped material is deployed from said hollow member, the first plane is angled relative to an axis of the hollow member or said locking wire by an angle α ranging from 120° to 170°, and the second plane is angled relative to the first plane by an angle β ranging from 10° to 60°.
2. The device as claimed in claim 1 , wherein said hollow member is a catheter.
3. The device as claimed in claim 1 , wherein said first loop is smaller than said second loop.
4. The device as claimed in claim 1 , wherein said angle α is about 150°.
5. The device claimed in claim 1 , wherein said angle β is about 60°.
6. The device as claimed in claim 1 , wherein a leading edge of said second loop comprises a pointed portion configured to puncture tissue.
7. The device as claimed in claim 1 , wherein said wire of memory shaped material further comprises a marker that is visible with electronic visualization means.
8. The device of claim 1 , wherein said locking wire is substantially straight.
9. The device of claim 1 , wherein:
said wire and said locking wire are retractable into said hollow member; and
prior to retraction into said hollow member, said locking wire is substantially straight.
10. A snare device for cutting a tissue, comprising:
a wire of memory shaped material twisted to define at least a first loop and a second loop, said wire being movable relative to a hollow member such that said first and second loops are deployable from and retractable into said hollow member; and
a locking wire translatable through at least one of said first and second loops; wherein:
said wire is distally translatable from said hollow member so as to dispose at least one of said first and second loops through a first aperture in said tissue, at least one of said loops being translatable over a surface of said tissue when said first and second loops are at least partially retracted into said hollow member;
said locking wire is distally translatable from said hollow member so as to extend at least a distal portion of said locking wire through a second aperture in said tissue after at least one of said first and second loops is disposed through said first aperture, so as to stop translation of one or more of said loops over said surface of said tissue;
said distal portion of said locking wire is operable to engage at least one of said first and second loops while it is extended through said second aperture; and
when said distal portion of said locking wire is engaged with at least one of said first and second loops, said locking wire and said first and second loops are operable in combination to cut said tissue by retracting said first and second loops into said hollow member.
11. The device as claimed in claim 10 , wherein said hollow member is a catheter.
12. The device as claimed in claim 10 , wherein to cut said tissue, said first loop and said second loop are deployed such that a first plane of said first loop and a second plane of said second loop are positioned substantially parallel to one another and adjacent to opposing sides of said tissue.
13. The device as claimed in claim 10 , wherein said first loop is adjustable to define a length of a cut to be formed in said tissue.
14. The device as claimed in claim 10 , wherein a leading edge of said second loop comprises a pointed portion configured to puncture said first aperture in said tissue.
15. The device as claimed in claim 10 , wherein said wire of memory shaped material further comprises a marker that is visible with electronic visualization means.
16. The device of claim 10 , wherein said locking wire is substantially straight.