Methods and devices are provided for dissecting tissue. In one embodiment, a surgical device can include an elongate shaft configured to be introduced into a body of a patient. A transducer coupled to the elongate shaft can be configured to deliver mechanical energy to the elongate shaft, e.g., axially along the elongate shaft, to rotate, vibrate, and/or flex the elongate shaft to facilitate dissection of tissue adjacent at least a leading end or a distal end of the elongate shaft. In some embodiments the elongate shaft can include at least two coaxial coils, and the transducer can be configured to move at least one of the coaxial coils to facilitate tissue dissection using the elongate shaft.
