Abstract: The present invention relates to a cost effective working tool useful for lateral resection of biological tissues by means of a flexible blade with an adjustable curve size. Said rod-like tool has a distal end, adapted to be inserted into a body cavity, and a proximal end, located adjacent to a user. The longitudinal axis of said maneuverable blade is parallel to the longitudinal axis of the said tool or shifted in respect to the same. The working tool comprising a bending mechanism, adapted to adjust the bending of said blade to a predetermined measure and a rotating mechanism, adapted to rotate said blade in a lateral, bi-directional movement in respect to the resected tissue such that a side-to-side resection is obtained. A novel method of lateral resecting of biological tissues by the same is also presented.