Systematic evaluation of stone basket dimensions.
OBJECTIVE
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.
Monga
Manoj
M
Department of Urologic Surgery, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Hendlin
Kari
K
Lee
Courtney
C
Anderson
J Kyle
JK
D004867:Equipment Design; D020709:Ureteroscopes