A medical device for removing an object from a body includes a retrieval basket having a distal section and a proximal section, at least two strands extending through the proximal section of the retrieval basket, and at least three prestressed filaments extending from a distal end of each of the at least two strands through the distal section of the retrieval basket. The filaments are spaced from each other through the entire distal section of the retrieval basket between a proximal end of the filaments and a distal end of the filaments. The filaments also converge at a distal end of the distal section of the retrieval basket, and the filaments are entwined to form each of the at least two strands.