Abstract: A hand tool is provided for immobilizing an implanted vascular access port in the body of a patient while a hypodermic needle is being withdrawn from an elastomeric septum that forms a seal for the access port. The tool includes an elongated handle and a V-shaped prong structure designed to straddle the needle so that the prongs apply a restraining force on the implanted access port. The skin-contact surfaces of the prongs are convexly curved, such that the prongs apply the desired force, whatever the position of the handle. The tool can be held in a range of different positions while still applying the necessary restraining force.