| 摘要 |
A minimally invasive medical retrieval device 10 useful for the removal of objects such as stones, calculi, concretions, foreign bodies and the like from the urinary, biliary, vascular or other systems includes a sheath 12 containing at least three wires 14 adjacently disposed in the sheath 12. At least one of the wires 14, and preferably all of them, can be moved longitudinally with respect to the sheath 12. The wires 14 have distal portions 16 which are formed so as to allow the engaging and removal of the object or objects. The distal portions 16 of the wires 14 preferably form a helical basket 22 or 40 particularly adapted for engaging urinary stones, calculi and concretions. Other grasping and manipulating shapes are useful as well. The wires 14 are substantially wedge-shaped in cross-section and substantially fill the entire cross-sectional area of the interior 26 of the sheath 12. The wedge-shaped wires 14 can be partly contained within a stainless steel cannula 28 positioned in the sheath 12. The sheath 12 can be of very small diameter, significantly smaller than the diameters of existing retrieval or extraction devices, preferably from about 0.5 to about 6.0 French. Unexpectedly, despite these small diameters, the baskets, graspers and the like into which the wedge-shaped wires 14 are formed simultaneously exhibit good resistance to twisting and bending, while being capable of being formed into shapes (such as helical baskets) not normally achieved with flat wires.
|
