Tissue resection snares

A tissue resection device comprising:

• an elongate shaft having a proximal end and a distal end;
• an actuation member extending at least partially through the elongate shaft, and being configured to reciprocate within the shaft between a retracted position and an extended position;
• and
• one or more snare wires extending through a lumen of the actuation member, emerging out from a distal portion of the actuation member, and having a flattened, rectangular cross-section, such that the snare wires orient substantially perpendicular to a plane containing tissue to be resected;
• wherein the interior portion of the actuation member includes a surface corresponding to the cross-section of the one or more snare wires to maintain the orientation of the snare wires with respect to the tissue.

A tissue resection device comprising:

• an elongate shaft having a proximal end and a distal end;
• an actuation member extending at least partially through the elongate shaft, and being configured to reciprocate within the shaft between a retracted position and an extended position;
• and
• a snare loop formed by one or more snare wires extending through a lumen of the actuation member, the snare loop being configured to engage tissue intended to be resected from a target site,
• wherein the snare loop includes a plurality of pinching structures positioned around different peripheral positions of the snare loop, configured to engage the tissue at locations of the pinching structures.