Apparatus and methods are described for dilating a portion of a
urethra surrounded by an enlarged
prostate. The apparatus includes dilation device, and a delivery device including a
balloon. The delivery device is configured to deliver the dilation device and the
balloon to the portion of the
urethra, while the dilation device is disposed in a
helical configuration on the delivery device. Upon the
balloon and the dilation device being disposed at the portion of the
urethra, the delivery device is configured to expand the balloon, thereby expanding the portion of the urethra, and to cause the dilation device to radially expand from the
helical configuration to an arc configuration. Subsequently, the delivery device is configured to
implant the dilation device, from outside the balloon, into tissue of the
prostate surrounding the portion of the urethra, while the portion of the urethra is expanded by the balloon.