Provox2 Voice Prosthesis
More recently, a second generation Provox voice prosthesis, intended for anterograde and retrograde use, Provox2, has been developed. This adapted prosthesis can be inserted during primary puncture at the time of laryngectomy, or during a secondary procedure at a later date, in the same manner as the original Provox prosthesis, using the separately available guide wire. Replacement in the outpatients office, however, can be carried out now in an anterograde manner directly through the tracheostoma.
For this replacement a simple disposable tool, consisting of a loading tube and an inserter, is available in the package (figure right). The Provox2 is available not only in 4.5, 6, 8, and 10 mm shaft lengths, but also in two additional length, i.e. 12.5 and 15 mm (figure left). The dimensions of the Provox2 prosthesis are comparable with those of the original Provox device, but the flanges have been adapted. The flanges are thinner: the esophageal flange is 1.5 mm instead of 1.6 mm to enable easier removal from the fistula tract, and the tracheal flange is 1.3 mm instead of 1.6 mm, to make the resistance towards the esophagus lower than that towards the trachea, to decrease the possibility of inadvertent dislodgment into the trachea. Furthermore, the valve construction has been improved and the tracheal flange contains the size number, allowing in vivo identification of the length of the prosthesis.