A manually-powered, syringe-like device designed specifically to aspirate clotted blood (e.g., thrombi, emboli), or other formed elements, from vessels of the arterial and venous systems to treat vascular obstruction and restore blood flow. The device plunger is withdrawn by the user to generate a negative pressure for aspiration, and collection containers and tubing may be included; it is typically intended to be connected to a patient contact catheter (not included). This is a single-use device.