A catheter device that is useable to extract material from a body conduit, such as a blood vessel, comprises a flexible catheter advanceable into the body conduit, an opening in the wall of the catheter that is in fluid communication with a material collection chamber, and a controllably arcuate segment along the catheter shaft, near the distal tip of the catheter and including the opening. Further said catheter may include a sliding member, located within a lumen of the catheter, that is used to move the material entering the catheter through the arcuate segment opening, into the material collection chamber and away from said opening. The catheter may include a single mechanism utilized to both generate a vacuum to cause material to enter the catheter at the arcuate segment opening and also cause the sliding member to travel, inside the catheter, moving material away from the opening and into the material collection chamber. Methods of utilizing such a catheter device to remove material from a body conduit are also disclosed.