Abstract: A vessel-occluding medical device for the use in diagnosis and/or treatment of cardiovascular disease in the human body includes an outer tube, an inner tube slidably housed within the outer tube, and a tubular sleeve comprising a generally U-shaped, direction reversing region, which moves along the length of the tubular sleeve, to assume radially contracted and radially expanded state as the inner and outer tubes move between the first and second positions. When the tubular sleeve is in the radially expanded state, the inner portion of the tubular sleeve has a funnel-shaped surface and a longitudinally-extending opening to permit material to pass therethrough for receipt of material into the inner tube.