Multicenter prospective crossover study on new prosthetic opportunities in post-laryngectomy voice rehabilitation.

The aim of this study was to assess the clinical experience of three Italian centers using the third generation Provox Vega prosthesis, in terms of device life and voice outcome, comparing the results with the second generation Provox 2 prosthesis in the same sample. A prospective multicenter crossover study was performed in three phases. In the first phase we performed a reassessment, for enrollment purposes, of patients who were categorized into four different groups [normal ­ group A; radio-treated ­ group B; gastroesophageal reflux disease (GERD) ­ group C; and elderly subjects ­ group D]. In the second and third phases, all patients were monitored for prosthetic device life and assessed for objective and subjective voice characteristics after introducing Provox 2 and Provox Vega prostheses. In patients with Provox 2 prosthesis, the mean life was 165 days in group A, 148 days in group B, 91 days in group C and 188 days in group D. In Provox Vega patients, mean in situ prosthesis life was 213 days in group A, 182 days in group B, 118 days in group C and 227 days in group D. The perceptual voice data showed a better rating across all parameters for the Provox Vega samples compared to those of Provox 2. In this paper, we report the first multicenter crossover study comparing different prosthetic models in the same patients, categorized in relation to different typologies of tracheoesophageal rehabilitative status. Result analyses confirmed an optimal stability of the Provox Vega compared to the Provox 2, in terms of device life and perceptual voice parameters.

Cellulose micro/nanofibres from Eucalyptus kraft pulp: preparation and properties.

There is growing interest in cellulose nanofibres from renewable sources for several industrial applications. However, there is a lack of information about one of the most abundant cellulose pulps: bleached Eucalyptus kraft pulp. The objective of the present work was to obtain Eucalyptus cellulose micro/nanofibres by three different processes, namely: refining, sonication and acid hydrolysis of the cellulose pulp. The refining was limited by the low efficiency of isolated nanofibrils, while sonication was more effective for this purpose. However, the latter process occurred at the expense of considerable damage to the cellulose structure. The whiskers obtained by acid hydrolysis resulted in nanostructures with lower diameter and length, and high crystallinity. Increasing hydrolysis reaction time led to narrower and shorter whiskers, but increased the crystallinity index. The present work contributes to the different widespread methods used for the production of micro/nanofibres for different applications.

Mechanisms of auditory impairment during acoustic neuroma surgery.

Hearing loss during removal of acoustic neuroma (AN) may be due to labyrinthine and/or neural and/or vascular damage. Surgical maneuvers relating to perioperative and postoperative hearing may give rise to mechanisms of auditory impairment. Recording action potentials from the intracranial portion of the cochlear nerve (CN) has proven particularly useful for identifying the mechanisms of iatrogenic auditory injury. In this paper intraoperative and postoperative auditory impairments are investigated in relation to surgical steps in a group of 47 subjects with AN (size ranging from 5 to 25 mm) undergoing removal by a retrosigmoid-transmeatal approach. Drilling of the internal auditory canal (IAC), removal of the AN from the IAC fundus, coagulation close to the CN, lateral to medial tumor traction, separation of the CN from the facial nerve, and stretching of the CN have proven to be the most critical surgical steps in hearing preservation. On the other hand, maneuvers such as intracapsular tumor removal, vestibular neurectomy, suction close to the AN, and closure of the IAC defect did not correlate with changes in auditory potentials. Predisposing factors to postoperative hearing deterioration were IAC enlargement greater than 3 mm, IAC tumor size greater than 7 mm, extracanalar tumor size greater than 20 mm, labyrinth medial to the IAC fundus, severe involvement of the CN in the IAC, preoperative abnormal auditory brainstem responses, and normal vestibular reflectivity. Age and preoperative hearing did not prove to be statistically related to postoperative hearing. The variations in morphology and latency of CNAPs are discussed in relation to the mechanisms of iatrogenic injury.