MEDICAL DEVICE INCLUDING TIPLESS BASKET

摘要

A minimally invasive, medical device (10) for removing stones calculus or the like from the renal or biliary systems includes a reversibly collapsible basket (12) and an elongated member (14) for delivering the basket (12) to the location of the stones, calculus or the like. The basket (12) is tipless and atraumatic in use, and includes at least one superelastic wire loop (20) and at lest one superelastic wire leg (26), the wire leg (26) preferably being incorporated into a second superelastic wire loop (24). The basket (12) is preferably formed from a shape memory material such as a suitable annealed nitinol alloy. The basket (12) includes means (28) for restricting relative movement of the first wire loop (20) and the wire leg (26) of the second wire loop (24), continuously formed with the first loop (20) and the leg (26) or the second loop (24). The movement restricting means (28) is preferably formed as a first smaller loop (30) in the first loop (20) interlocked with a second smaller loop (32) and the leg (26) or in the second loop (24). The elongated member (14) is preferably a flexible sheath or the like (34) of a length suitable for introduction of the basket (12) into the major and minor renal calyxes. The first loop (20) and the leg (26) or the second loop (24) have longitudinally extending portions (40 and 46) slidably received in the flexible sheath or the like (34). In this way the basket (12) can be retracted into or extended from the elongated member (14). The device (10) is particularly advantageous in being kink-free during use and in possessing a useful diameter significantly smaller than other eggwhip-type retrieval devices.