In this article we theoretically construct circular thin-shell wormholes in a
2+1 dimensional spacetime. The construction is symmetric with respect to the
throat. We present a general formalism for the study of the mechanical
stability under perturbations preserving the circular symmetry of the
configurations, adopting a linearized equation of state for the exotic matter
at the throat. We apply the formalism to several examples.Comment: 14 pages, 7 figures; v2: improved version, new references adde