Abstract: A catheter apparatus for insertion into a blood vessel includes a tubular catheter hub, having a side wall with a side wall portion formed of deformable material, and having a proximal end, a distal end, and a mechanism for inwardly collapsing the side wall portion to occlude the apparatus, resilient sealing material contained within the catheter hub having an axially oriented opening to permit fluid communication between the proximal end and the distal end of the catheter hub, for compressing to form a seal, closing the axially oriented opening and creating a seal, and a catheter extending from the distal end, substantially coaxially with the hub. A clamping mechanism is preferably provided for inwardly collapsing the side wall portion. The clamping mechanism preferably includes two spaced apart compression flanges extending outwardly from the side wall portion for gripping and pushing toward each other to compress the sealing material and occlude the apparatus.