Assessment of a new tipless nitinol stone basket and comparison with an existing flat-wire basket

Flexible nephroscopes and ureteroscopes make it possible to see calculi in remote calices, but it is often impossible to remove these with existing te chnology. Flat-wire baskets impede deflection and can traumatize the papill a, This study compares the performance of a new 3.2F tipless nickel-titaniu m (Nitinol) basket with that of an existing 3.0F flat-wire basket. Specific ations were compared using a 15F nephroscope and a 7.5F flexible ureterosco pe in a pig kidney model. A calculus was placed in a calix, and the author and two residents were timed while using both baskets to retrieve the stone . To open fully, the flat-wire basket needed to protrude 1.2 cm further tha n the tipless basket, The tipless basket did not restrict deflection of the nephroscope, whereas the flat-wire basket limited flexion by 24 degrees an d extension by 28 degrees, The tipless basket did not restrict extension of the 7.5F ureteroscope but limited flexion by 10 degrees, The flat-wire bas ket limited flexion by 79 degrees and extension by 72 degrees, Using the pi g kidney model, the three operators took a mean of 5.3, 11.8, and 6.4 secon ds to catch the stone with the tipless basket. Using the flat-wire basket, the mean times were 15.3, 34.5, and 28.9 seconds (combined data: 8.2 second s for the tipless basket and 27.8 seconds with the flat-wire basket; P = 0. 0001), Only the flat-wire basket was seen to traumatize the papilla, The Ni tinol tipless basket has significant advantages over the flat-wire basket.