A tissue removal device (104; 3100; 1800), comprising: a housing (140; 3102; 1740); a hollow needle (148; 3104; 4404; 1704) extending from the housing and comprising an open distal tip (176; 3106) outside the housing; an ultrasonic transducer positioned in the housing and configured for mechanically vibrating the needle; an aspiration line (144; 3222; 1722) communicating with the needle and configured for communicating with a vacuum source (108; 3714) outside the housing, wherein the needle and the aspiration line define an aspiration path from the distal tip, through the housing, and out from the housing to the vacuum source; and a vacuum pulsing device (156; 1056; 1256; 1556; 1716; 1780) positioned outside the housing and configured for generating vacuum pulses at the distal tip, the vacuum pulsing device comprising an actuator (1010; 1510; 3340; 3780; 4422; 4432) and a movable member (1006; 1206; 1406; 1506; 3338; 4420; 4430), wherein the actuator is configured for moving the movable member alternately between a closed position that obstructs the aspiration path and an open position, characterized by the vacuum pulsing device configured as an attachment to the housing, a first coupling member at the proximal end of the housing, the vacuum pulsing device including a second coupling member configured for being coupled to the first coupling member in a fluid-tight manner, and the vacuum pulsing device positioned external to the housing of the tissue removal device in a manner that isolates the vacuum pulsing device from the ultrasonic energy generated within the housing, wherein damping material is interposed in one or more locations between the housing and the vacuum pulsing device to dampen vibrations. a housing (140; 3102; 1740); a hollow needle (148; 3104; 4404; 1704) extending from the housing and comprising an open distal tip (176; 3106) outside the housing; an ultrasonic transducer positioned in the housing and configured for mechanically vibrating the needle; an aspiration line (144; 3222; 1722) communicating with the needle and configured for communicating with a vacuum source (108; 3714) outside the housing, wherein the needle and the aspiration line define an aspiration path from the distal tip, through the housing, and out from the housing to the vacuum source; and a vacuum pulsing device (156; 1056; 1256; 1556; 1716; 1780) positioned outside the housing and configured for generating vacuum pulses at the distal tip, the vacuum pulsing device comprising an actuator (1010; 1510; 3340; 3780; 4422; 4432) and a movable member (1006; 1206; 1406; 1506; 3338; 4420; 4430), wherein the actuator is configured for moving the movable member alternately between a closed position that obstructs the aspiration path and an open position, characterized by the vacuum pulsing device configured as an attachment to the housing, a first coupling member at the proximal end of the housing, the vacuum pulsing device including a second coupling member configured for being coupled to the first coupling member in a fluid-tight manner, and the vacuum pulsing device positioned external to the housing of the tissue removal device in a manner that isolates the vacuum pulsing device from the ultrasonic energy generated within the housing, wherein damping material is interposed in one or more locations between the housing and the vacuum pulsing device to dampen vibrations.