A helical element for insertion into tissue comprises a helical element having an insertion end, a protruding end and an open central area within the wire, rods, filaments, cables or the like that form the helix. The helical element has at least its insertion end covered by a cap of a water-soluble or water-dispersible composition. The cap is provided with a surface shape in a cross-section in which surface variations are present in the cross-section which create a surface orientation where a line from the center of the cross-section can intersect the surface, and a line perpendicular to said radius at a point of intersection with said surface forms four quadrants, three of said quadrants containing water-soluble or water-dispersible cap material. There is either a hollow area within the composition within the open central area or the material is more porous than the remaining material. The helical element preferably comprises an electrical lead, such as a positive endocardial lead, with an electrode at the protruding or distal end of the lead.The helical element may comprise any biocompatable material with sufficient structural integrity to provide a secure attachment to tissue in a patient. Where the helical element is also to provide an active (electrically active) function, the composition of the helical element should also be electrically conductive.