There are established procedures for removing thrombi from a patient's vasculature by percutaneous insertion of appropriate treatment apparatus into the vasculature of the patient. A procedure which is well documented involves the use of an assembly which includes a balloon catheter provided with two inflatable balloons which are spaced from one another at the distal end of the catheter. The balloon catheter is inserted endoluminally into the patient's vasculature until the balloons are located either side of a thrombus to be removed. The balloons are then inflated so as to close off that part of the patient's vessel. The assembly includes provision for feeding into the space between the two inflated balloons a thrombolytic or other lytic agent, typically through a lumen of the balloon catheter. The thrombolytic agent will dissolve the thrombus located between the two inflated balloons, whereupon the dissolved thrombus material can be removed, typically by aspiration. Particularly when a thrombus is established, that is when the thrombus is dense and well set, it can take a significant time to dissolve the thrombus and thus remove this from the patient.
Examples of thrombus treatment apparatus can be found, for example, in U.S. Pat. No. 5,279,546, U.S. Pat. No. 5,059,178 and U.S. Pat. No. 5,925,016.