A tissue removal device, comprising: a housing; a rigid aspiration cannula extending from the housing to a distal tip outside the housing, the distal tip having a distal tip opening; a valve assembly disposed in the housing, the valve assembly comprising a valve port communicating with the aspiration cannula in a fluid-sealed manner; an aspiration line communicating with the valve assembly and passing through the housing of the tissue removal device to provide a fluid connection between the aspiration cannula and a collection receptacle comprising an interior; an aspiration inlet communicating with the aspiration line and the interior; a vacuum outlet communicating with the interior and configured for communication with the vacuum source, wherein the vacuum source creates a vacuum in a fluid circuit comprising the collection receptacle, the aspiration line, and the aspiration cannula, the valve assembly being controlled to open and close to provide a pulsed vacuum; a pneumatically-driven actuator configured for moving the valve assembly between an open position and a closed position, wherein: at the open position, the valve port is open wherein the valve assembly defines an aspiration path through the aspiration cannula and the valve assembly, and at the closed position, the valve port is closed wherein the valve assembly prevents vacuum from being applied at the distal tip; and wherein the valve assembly comprises an inner cannula and an outer cannula coaxially disposed about at least a portion of the inner cannula, the inner cannula is configured for communicating with the vacuum source via the aspiration line and is linearly movable by the actuator between the open position and the closed position, the valve port is formed in the outer cannula, at the open position the aspiration path passes through the outer cannula via the valve port and into the inner cannula, and at the closed position the inner cannula blocks the valve port. a housing; a rigid aspiration cannula extending from the housing to a distal tip outside the housing, the distal tip having a distal tip opening; a valve assembly disposed in the housing, the valve assembly comprising a valve port communicating with the aspiration cannula in a fluid-sealed manner; an aspiration line communicating with the valve assembly and passing through the housing of the tissue removal device to provide a fluid connection between the aspiration cannula and a collection receptacle comprising an interior; an aspiration inlet communicating with the aspiration line and the interior; a vacuum outlet communicating with the interior and configured for communication with the vacuum source, wherein the vacuum source creates a vacuum in a fluid circuit comprising the collection receptacle, the aspiration line, and the aspiration cannula, the valve assembly being controlled to open and close to provide a pulsed vacuum; a pneumatically-driven actuator configured for moving the valve assembly between an open position and a closed position, wherein: at the open position, the valve port is open wherein the valve assembly defines an aspiration path through the aspiration cannula and the valve assembly, and at the closed position, the valve port is closed wherein the valve assembly prevents vacuum from being applied at the distal tip; and wherein the valve assembly comprises an inner cannula and an outer cannula coaxially disposed about at least a portion of the inner cannula, the inner cannula is configured for communicating with the vacuum source via the aspiration line and is linearly movable by the actuator between the open position and the closed position, the valve port is formed in the outer cannula, at the open position the aspiration path passes through the outer cannula via the valve port and into the inner cannula, and at the closed position the inner cannula blocks the valve port. at the open position, the valve port is open wherein the valve assembly defines an aspiration path through the aspiration cannula and the valve assembly, and at the closed position, the valve port is closed wherein the valve assembly prevents vacuum from being applied at the distal tip; and wherein the valve assembly comprises an inner cannula and an outer cannula coaxially disposed about at least a portion of the inner cannula, the inner cannula is configured for communicating with the vacuum source via the aspiration line and is linearly movable by the actuator between the open position and the closed position, the valve port is formed in the outer cannula, at the open position the aspiration path passes through the outer cannula via the valve port and into the inner cannula, and at the closed position the inner cannula blocks the valve port.