Evaluation of combined growth media for in vitro cultivation of oropharyngeal biofilms on prosthetic silicone.

In the upper aerodigestive tract, biofilm deposits by oropharyngeal microbes can cause failure of medical polymer devices like voice prostheses. Previous studies on testing of inhibitive strategies still lack of comparability due to varying study protocols concerning growth media, microbial species and growth conditions. Goal of the study was therefore to test cultivation of a mixed biofilm of isolated oropharyngeal microbes under in vitro growth conditions using mixtures of common growth media. Mixtures of yeast peptone dextrose medium (YPD), fetal bovine serum (FBS), RPMI 1640, Yeast nitrogen base medium (YNB) and brain heart infusion (BHI) were tested to grow mixed biofilm deposits of Candida albicans, Candida tropicalis, Staphylococcus aureus, Streptococcus epidermidis, Rothia dentocariosa and Lactobacillus gasseri on medical grade silicone. Periodic assessment of living biofilm was performed over 22 days by a digital microscope and the cultivated biofilm structures were analyzed by scanning electron microscopy after completion of the study. Mixtures of BHI, YPD and FBS improved microscopic growth of multispecies biofilm deposits over time, while addition of RPMI and YNB resulted in reduction of visible biofilm deposit sizes. A mixtures of FBS 30% + YPD 70% and BHI 30% + YPD 70% showed enhanced support of permanent surface growth on silicone. Growth kinetics of in vitro multispecies biofilms can be manipulated by using mixtures of common growth media. Using mixtures of growth media can improve growth of longterm multispecies oropharyngeal biofilm models used for in vitro testing of antibiofilm materials or coatings for voice prostheses.

International consensus (ICON) on basic voice assessment for unilateral vocal fold paralysis.

There is a growing need for evaluation tools allowing the quantification of the outcome after voice surgeries. Since the end of the 1990s, multiple unfruitful attempts have been made to reach a consensus, including the Dejonckere protocol for the European Laryngological Society in 2001. This suggested to perform objective and quantifiable measures in the following domains: perception, acoustic, aerodynamic, self-evaluation by the patient and videolaryngostroboscopy. But in a PubMed® search with the keywords "Voice Assessment" and "Voice Outcome" since 2001 retrieving 452 articles, only 33 of them were using methods taking into account the first four dimensions proposed by Dejonckere. To elaborate a new and simpler protocol, we chose to focus on unilateral vocal fold paralyses (UVFP), which represents a homogeneous disease in terms of physiology. This protocol was elaborated on the basis of a review of the literature and of the database and experience of the IFOS panel members. In summary, our group recommends the use and implementation of the ELS "basic protocol" with some minor modifications. Voice audio recordings are an indispensable prerequisite, and may even have medico-legal implications. We recommend the systematic use of the Voice Handicap Index (VHI). Perceptual analysis must be performed by using Hirano's GRB scale and voice breathiness has to be prioritized. Currently, acoustic analysis remains optional given the lack of data to support clinical usefulness. Aerodynamic studies should include at a minimum an evaluation of the Maximum Phonation Time, calculated in seconds following multiple trials in order to obtain a recording representing the patient's best possible glottis closure.

[Voice disorders in childhood]. / Stimmstörungen im Kindesalter.

Voice disorders in the pediatric population are relatively common. The education of families, teachers and clinical staff on etiology and treatment of pediatric voice disorders have led to greater attention being paid to hoarseness in childhood and improving early detection of pediatric voice disorders. Pediatric voice problems can have a number of causes. Most commonly, childhood dysphonia is caused by vocal fold nodules due vocal ab- and misuse. Other reasons might be congenital laryngeal dysplasia, vocal fold cysts and laryngeal papilloma. Medical examination is necessary in order to initiate appropriate treatment. In the case of vocal fold cysts and laryngeal papilloma, phonosurgery is indicated. Vocal fold nodules should be treated by voice therapy in order to change vocal behaviour. If voice therapy fails, phonosurgical intervention is recommended, since vocal fold nodules can persist into adulthood with a negative impact on voice quality.

High risk of unilateral recurrent laryngeal nerve paralysis after esophagectomy using cervical anastomosis.

The goal of this study was to estimate the incidence of temporary and permanent unilateral recurrent laryngeal nerve paralysis (URLNP) after esophagectomies with cervical anastomosis and to determine the impact of surgical technique, tumor type, tumor localization and age on the incidence of URLNP. From March 2002 to November 2009, 84 patients underwent a laryngoscopical evaluation before and after esophagectomy with cervical anastomosis prospectively. If the postoperative URLNP recovered within 6 months, the paresis was classified as transient; if not, it was defined as permanent. The results indicate that the overall incidence of postoperative URLNP was 50% (42/84). Twenty-four of the 84 patients (28.6%) showed a transient URLNP. A permanent URLNP was observed in 9 of the 84 patients (10.7%). The remaining 9 of the 84 patients (10.7%) were categorized as paresis with unknown clinical outcome due to missing follow-up. There were significantly more postoperative URLNPs in the group operated by transthoracic esophagectomy than by transhiatal esophagectomy (p < 0.001). Multifocal tumors and those localized suprabifurcational showed a higher incidence of postoperative URLNP than unifocal lesions with infrabifurcational localization (p = 0.046). Histological type of tumor and patients' age had no impact on URLNP. The high incidence of URLNP in our study underlines the high risk of URLNP after esophagectomy with cervical anastomosis, and consequently the importance of routine laryngoscopic pre- and postoperative evaluation of the vocal fold motility.

[Examination of biofilm related material deterioration on 20 PROVOX2 voice prostheses by scanning electron microscopy]. / Elektronenmikroskopische Untersuchungen zur Biofilmbildung auf 20 PROVOX2 Stimmventilen.

BACKGROUND: Mechanical impairment of valve function by biofilms is considered to cause loss of function of voice prostheses in laryngectomized patients. Material deterioration and infiltrative growth of Candida associated biofilms have already been observed on Groningen Buttons. Goal of the study was the examination of biofilm formation and material damages on PROVOX2 voice prostheses. METHODS: 20 PROVOX2 voice prostheses were withdrawn from 17 laryngectomized patients due to aspiration (mean in-vivo time: 118 d, median 98 d). Microbial spectrum, colonization patterns and morphologies of prosthesis damage were assessed using standard microbiologic procedures and scanning electron microscopy. RESULTS: Biofilm with various growth patterns predominantly adhered to the esophageal parts of the prostheses. Microbiologic findings showed Candida species as main colonisers on esophageal surfaces. Different morphologies of surface alteration and material infiltration of the polymer material were identified on 8 prostheses with 35 d of in-vivo time minimum. CONCLUSION: Valve dysfunction of PROVOX2 voice prostheses can be attributed to biofilm formation on esophageal surfaces and edges of the valve flap and seating. The identified morphologies of material damage and invasive growth indicate towards lytic processes of the polymer material due to Candida associated biofilms.