An aspiration system includes an aspiration catheter including a tubular aspiration member having a proximal end, a distal end, and a lumen, and configured to at least partially extend out of the lumen of an elongate tubular member and into the vasculature of a subject, an elongate support member coupled to the tubular aspiration member and extending between the proximal end of the aspiration catheter and the proximal end of the tubular aspiration member, a high pressure injection lumen extending within the elongate support member and having a distal end including a curved portion configured to change a direction of fluid flow by at least about 90°, at least one orifice located at the distal end of the high pressure injection lumen configured to allow liquid to be released into the lumen of the tubular aspiration member, and an annular seal carried by the tubular aspiration member and configured to create a liquid seal against the inner surface of the elongate tubular member.
