Disclosed embodiments include apparatuses, systems, and methods for cutting an opening in a tissue wall. In an illustrative embodiment, an apparatus includes an inner cutting member having a first cylindrical body supporting at least one first cutting surface at a distal end. The first cutting surface faces a first rotational direction relative to an axis of the first cylindrical body and has a first cutting edge at an outer periphery of the first cylindrical body. The apparatus also includes an outer cutting member having a second cylindrical body concentrically disposed around the first cylindrical body and supporting at least one second cutting surface at the distal end. The second cutting surface faces a second rotational direction relative to the axis and has a second cutting edge at an inner periphery of the second cylindrical body. A tissue is rotatably scissorable between the first cutting edge of the inner cutting member and the second cutting edge of the outer cutting member responsive to application of the distal end of the apparatus against a tissue and counter-rotating the inner cutting member and the outer cutting member.
