A medical device clamping assembly includes proximal and distal axially aligned members. The proximal and distal members are movable relative to each other. A channel is defined through the members for receipt of at least a portion of a treatment device therethrough. A clamping member is configured between the proximal and distal members and defines a portion of the channel. The clamping member is actuated between an unclamped configuration and a clamped configuration by moving one of the distal or proximal members relative to the other. In its clamped position, the clamping member clamps upon and restricts axial movement of the treatment device through the assembly; however, the assembling may move on or within the treatment device and does not necessarily limit at least partial retraction of the device from a patient but rather only restricts insertion of the device beyond that point at which the assembly contacts a stopper.