By way of illustration only and not by way of limitation, the distal end portion may comprise one or a combination of the following materials: metals and alloys such as nickel-titanium alloy (???nitinol???) or medical grade stainless steel, and/or plastic and polymers such as polyether ether-ketone (???PEEK???), polytetrafluoroethylene (PTFE), nylon and/or a polyether block amide (???PEBA???), pol