The TE-fistula tract of a Provox prosthesis does not need dilation during replacement of the device. However, if a prosthesis with a smaller diameter is replaced by one of the Provox prostheses, the procedure might be easier after some dilation of the fistula tract, using the Provox Dilator (figure). Some guidelines are: in a 16 Fr fistula tract insertion of a Provox 4.5, 6, or 8 mm can be attempted without dilation, but in most instances, especially in case a longer prosthesis is needed, the dilator should be applied first. The device can be lubricated with some gel and gently inserted in the TE-fistula until a diameter of 24 Fr and left in situ for 10-15 minutes (figure). After removal of the dilator, the insertion of the Provox prosthesis should be carried out immediately, in order not to loose the dilation effect. In a 20 Fr fistula tract dilation is seldom needed, because of the retrograde insertion of the Provox (1) prosthesis and the conical end of the Provox2 insertion tube.