An apparatus for performing a medical procedure includes a balloon comprising an inflatable body. A first releasable or frangible connection is provided to maintain the body at a first diameter up to a first inflation pressure, and to release, such as by disconnecting, and thus allow the body to assume a second diameter, such as at a second inflation pressure greater than the first inflation pressure or upon a manual release of the connection by a clinician. Multiple releasable or frangible connections may be provided, including between portions (folds) of the inflatable body of the balloon. This disclosure also pertains to a non-compliant or semi-compliant balloon having a first inflation diameter corresponding to a first range of inflation pressures and a second inflation diameter corresponding to a second inflation pressure greater than the first range of inflation pressures.
