A balloon-manipulating device for a balloon catheter includes, in some embodiments, a tubular body, a longitudinal hole through a least a portion of the tubular body, one or more balloon-compressing pieces of a sidewall of the tubular body, and one or more balloon-letting through holes through the sidewall. The longitudinal hole extends from an opened proximal end of the tubular body to at least a distal end portion of the tubular body. The longitudinal hole is configured for inserting a balloon-catheter shaft in the longitudinal hole. Each balloon-compressing piece is configured for compressing a different portion of an inflated balloon-catheter balloon when the balloon-manipulating device is disposed over the balloon. Each balloon-letting through hole is configured for allowing therethrough a different portion of an inflated balloon-catheter balloon when the balloon-manipulating device is disposed over the balloon. Also disclosed is a balloon catheter assembly and methods of the foregoing.
