Systematic evaluation of stone basket dimensions.

OBJECTIVES: To evaluate 17 commercial stone baskets for characteristics we believe are favorable for stone extraction.

METHODS: The ACMI (Sur-Catch 3.0), Bard (Dimension 3.0), Boston Scientific (Zero-tip 2.4/3.0, Segura 2.4/3.0, Gemini 3.0, Parachute 3.1), Cook (N-Circle 2.2/3.0/3.2, N-Force 3.2, Flatwire 2.0), and Sacred Heart (Halo 1.9, Vantage 2.4, Summit 3.0, Hercules 3.0) were tested in triplicate. The maximal basket width was measured with a digital caliper as the basket length was opened in 0.5 to 2-mm increments using a mechanical caliper under optical light microscope visualization. Baskets were rated for the linearity of opening and length at which the target basket width (5 mm) was reached.

RESULTS: The only basket to exhibit linear opening was the N-Circle. All other baskets opened in an exponential fashion, with the initial excursion in length corresponding to little change in basket width, followed by a rapid increase in basket width as the basket extended further. The N-Circle 2.2F, 3.0F, and 3.2F baskets reached the target basket width at a basket length of 9.4, 9.7, and 9.6 mm, respectively. As a group, the tipless baskets opened more rapidly to the target basket width (9.4 to 14.8 mm) than did the flat-wire baskets (17.5 to 22.7 mm) or helical baskets (18.6 to 24.8 mm).

CONCLUSIONS: A basket that requires a shorter basket excursion to reach a 5-mm width will be easier to maintain in the field of view. Linear basket opening provides the operator with greater control to engage a stone. After closure of a basket on a 5-mm stone, the larger the basket length dimension, the greater the likelihood the calculus may escape.