DEVELOPMENT AND CLINICAL-EVALUATION OF A 2ND-GENERATION VOICE PROSTHESIS (PROVOX((R))2), DESIGNED FOR ANTEROGRADE AND RETROGRADE INSERTION

Prosthetic voice restoration has considerably improved the results of vocal rehabilitation after total laryngectomy, and is presently the me thod of choice for many health-care providers treating laryngectomized patients. The Provox(R) voice prosthesis, developed in the Netherland s Cancer Institute, is an indwelling device that has been applied in r ecent years with regular success. Its retrograde replacement method, u sing a disposable guide wire, assures reliable, atraumatic positioning of the prosthesis in the tracheoesophageal fistula. However, the meth od sometimes may be uncomfortable for the patient; therefore an adapte d prosthesis and new replacement equipment were developed, which enabl e bidirectional insertion, i.e. not only in the traditional retrograde manner through the pharynx, but especially in an anterograde manner t hrough the stoma. This second-generation voice prosthesis (Provox(R)2) was studied in a prospective clinical trial in 44 patients (33 experi enced patients, seven first-time replacements and four primary inserti ons). The study demonstrated that the anterograde insertion with the P rovox(R)2 system was applicable in all patients, making the voice pros thesis even easier to handle than with the traditional retrograde meth od. A stenosis of the pharyngoesophageal segment no longer interfered with the replacement. In addition, the patients judged the new method as being favourable, reporting significantly less discomfort during th e replacement procedure (paired Student's t-test: p < 0.0001). Further more, the adapted voice prosthesis could be removed from the tracheoes ophagal fistula without excessive force (mean 7.9 N, range 6.0-14.0 N) , more easily than the original Provox(R) (mean 20.9 N, range 5.5-25.0 N). It can be concluded that this second-generation indwelling voice prosthesis (Provox(R)2) seems to be a further improvement in the appli cation of this voice rehabilitation system, not only simplifying the r eplacement procedure, but also diminishing the discomfort for the pati ent.