I once experimented with some small diameter electrical grade heat shrink tubing. It was possible to use a fine sewing needle to expand the entire inside diameter to make it easier to pass through the monofilament. Perhaps this might also work with the Vention Medical tubing although I am unsure what micro sized tapered instrument would fit into a .010 diameter tube for the purpose of stretching it. Maybe a piece of .015 inch diameter music wire with a finely ground tip.