Retrieval snare device and method
The present invention relates generally to devices and methods for retrieving or manipulating objects within a lumen. More specifically, embodiments of the invention relate to devices and methods for retrieving or manipulating medical devices from a body lumen. One embodiment of the present invention provides a novel and improved retrieval snare and method of fabricating and using the same. The snare includes a snare wire, having a distal end and a proximal end, for use in the human anatomy, such as but not limited to blood vessels, pulmonary airways, reproductive anatomy, gastrointestinal anatomy, and organs such as the kidneys or lungs. The device enables a user to capture a foreign object located within the human anatomy, grasp said object in a controlled manner, and retrieve and remove said object from the human anatomy.
1. A method for capturing an object in a lumen defined by a lumen wall, the method comprising:
advancing a sheath within the lumen, the sheath having a proximal end and a distal end, until the distal end of the sheath is proximal to the object;
deploying a plurality of loop elements of a snare out of the distal end of the sheath in a propeller-like configuration, wherein each of the plurality of the loop elements emanates from and returns to the distal end of the sheath, and wherein at least some of the plurality of loop elements comprise a first portion disposed out of the distal end of the sheath and extending distally of the distal end of the sheath and a second portion disposed out of the distal end of the sheath and extending proximally of the distal end of the sheath when the snare is fully deployed; and
capturing a portion of the object with at least one of the plurality of loop elements.
2. The method of claim 1 further comprising withdrawing the loop elements in a proximal direction to engage the portion of the object.
3. The method of claim 1 further comprising rotating the loop elements to engage the portion of the object.
4. The method of claim 1 further comprising retracting the portion of the object within the sheath.
5. The method of claim 1 further comprising advancing an outer sheath over the object.
6. The method of claim 1 further comprising advancing the snare to a full deployment detent on the snare.
7. The method of claim 1 further comprising decoupling a snap fitting holding together the sheath and the snare.
8. A method for capturing an object in a lumen defined by a lumen wall, the method comprising:
advancing a sheath within the lumen, the sheath having a proximal end and a distal end, until the distal end of the sheath is proximal the object;
deploying a plurality of loop elements of a snare out of the distal end of the sheath until the loop elements achieve substantially full apposition with the circumference of the lumen wall, wherein each of the plurality of loop elements emanates from and returns to the distal end of the sheath, and wherein at least some of the plurality of loop elements comprise a first portion disposed out of the distal end of the sheath and extending distally of the distal end of the sheath and a second portion disposed out of the distal end of the sheath and extending proximally of the distal end of the sheath when the snare is fully deployed; and
capturing a portion of the object with at least one of the plurality of loop elements.
9. The method of claim 8 , further comprising aligning a radiopaque marker offset from the distal end of the sheath with a radiopaque feature of the object.
10. The method of claim 9 , wherein the radiopaque feature of the object is a retrieval element.
11. The method of claim 8 , wherein the plurality of loop elements have an oblong deployed configuration.
12. The method of claim 8 , further comprising advancing the distal end of the sheath over the captured object.
13. The method of claim 12 , wherein the distal end of the sheath inverts as the sheath is advanced over the captured object.
14. The method of claim 8 , further comprising aligning a radiopaque marker offset from the distal end of the sheath with a retrieval feature located at a proximal end or a distal end of the object.
15. The method of claim 14 , further comprising deploying the plurality of loop elements between the retrieval feature and an anchor on the object.
16. The method of claim 15 , wherein the step of deploying the plurality of loop elements between the retrieval feature and the anchor comprises advancing the plurality of loop elements a predetermined distance past the distal end of the sheath.
17. The method of claim 14 wherein each of the plurality of loop elements is formed from a separate wire.