CT findings of the temporal bone in CHARGE syndrome: aspects of importance in cochlear implant surgery.

To provide an overview of anomalies of the temporal bone in CHARGE syndrome relevant to cochlear implantation (CI), anatomical structures of the temporal bone and the respective genotypes were analysed. In this retrospective study, 42 CTs of the temporal bone of 42 patients with CHARGE syndrome were reviewed in consensus by two head-and-neck radiologists and two otological surgeons. Anatomical structures of the temporal bone were evaluated and correlated with genetic data. Abnormalities that might affect CI surgery were seen, such as a vascular structure, a petrosquamosal sinus (13 %), an underdeveloped mastoid (8 %) and an aberrant course of the facial nerve crossing the round window (9 %) and/or the promontory (18 %). The appearance of the inner ear varied widely: in 77 % of patients all semicircular canals were absent and the cochlea varied from normal to hypoplastic. A stenotic cochlear aperture was observed in 37 %. The middle ear was often affected with a stenotic round (14 %) or oval window (71 %). More anomalies were observed in patients with truncating mutations than with non-truncating mutations. Temporal bone findings in CHARGE syndrome vary widely. Vascular variants, aberrant route of the facial nerve, an underdeveloped mastoid, aplasia of the semicircular canals, and stenotic round window may complicate cochlear implantation.

Death in CHARGE syndrome after the neonatal period.

CHARGE syndrome is a multiple congenital anomaly syndrome that can be life-threatening in the neonatal period. Complex heart defects, bilateral choanal atresia, esophageal atresia, severe T-cell deficiency, and brain anomalies can cause neonatal death. As little is known about the causes of death in childhood and adolescence, we studied post-neonatal death in patients with CHARGE syndrome. We collected medical data on three deceased children from a follow-up cohort of 48 CHARGE patients and retrospectively on an additional four deceased patients (age at death 11 months to 22 years). We analyzed the factors that had contributed to their death. In five patients respiratory aspiration had most likely contributed to premature death, one died of post-operative complications, and another choked during eating. From our findings and a literature review, we suggest that swallowing problems, gastro-esophageal reflux disease, respiratory aspiration and post-operative airway events are important contributors to post-neonatal death in CHARGE syndrome. Cranial nerve dysfunction is proposed as the underlying pathogenic mechanism. We recommend every CHARGE patient with feeding difficulties to be assessed by a multidisciplinary team to evaluate cranial nerve function and swallowing. Timely treatment of swallowing problems and gastro-esophageal reflux disease is important. Surgical procedures on these patients should be combined whenever possible because of their increased risk of post-operative complications and intubation problems. Finally, we recommend performing autopsy in deceased CHARGE patients in order to gain more insight into causes of death.

Influence of the Provox Flush, blowing and imitated coughing on voice prosthetic biofilms in vitro.

OBJECTIVE: This study investigates the effect of regular airflow, as an isolated single factor, through Groningen and Provox2 voice prostheses on biofilm formation. MATERIAL AND METHODS: Groningen and Provox2 voice prostheses were placed in a modified Robbins device and inoculated with the total microflora from an explanted Groningen voice prosthesis. After 3 days, prostheses were either flushed 3 times per day with the Provox flush, treated with an airflow using an increasing order of air pressure (10, 15 and 20 cmH2O) or vigorously perfused by means of imitated coughing (air pressure 20 cmH2O). As a control, prostheses were left undisturbed to promote biofilm growth. Following flushing, blowing or coughing, each artificial throat was perfused with 200 ml of phosphate-buffered saline. This procedure was repeated three times a day for 9 days. At the end of each day, the artificial throats were filled with growth medium for 30 min and left empty during the night after draining. After 12 days the microflora on each voice prosthesis was quantified by plating on blood agar for bacteria and on de Man, Rogosa and Sharpe agar for yeasts. RESULTS: The use of the Provox flush reduced bacterial prevalence on Groningen and Provox2 voice prostheses to 71% and 45% of the control values, respectively, without affecting the number of yeasts. Increasing airflows and imitated coughing yielded reductions of 45-70% in bacterial and yeast prevalence on Provox2 voice prostheses. On the Groningen voice prostheses the effects of increasing airflows and imitated coughing were less pronounced: reductions in bacterial and yeast prevalence of 56-87% were observed. CONCLUSION: This study shows that use of the Provox flush has a cleansing effect, especially on Provox2 voice prostheses, and furthermore suggests that daily airflow through voice prostheses as part of a daily maintenance scheme reduces biofilm formation and can be expected to prolong the life of these devices.

Biofilm formation on voice prostheses: in vitro influence of probiotics.

In order to determine the influence of probiotic bacteria on biofilm formation on Groningen and Provox 2 voice prostheses in an artificial throat, we grew biofilms on both types of voice prostheses and exposed them 3 times daily to a probiotic bacterial suspension. As a control, we perfused an artificial throat with phosphate-buffered saline solution. Perfusion with Lactococcus lactis 53 suspension reduced the percentage numbers of bacteria and yeasts, respectively, on the Groningen prostheses to 17% and 22% and on the Provox 2 prostheses to 19% and 45%, compared to the number of colony-forming units on the control prosthesis, which was set at 100%. A suspension of Streptococcus thermophilus B reduced the percentage numbers of bacteria and yeasts, respectively, on the Groningen prostheses to 53% and 33% and on the Provox 2 prostheses to 14% and 0%, as compared to the control prosthesis. All other probiotic strains tested caused some reduction in the percentages of bacteria or yeasts, but strong differences between the types of prostheses were observed. In conclusion, L. lactis 53 and S. thermophilus B strongly reduce the occurrence of yeasts and bacteria in voice prosthetic biofilms.

Effect of probiotic bacteria on prevalence of yeasts in oropharyngeal biofilms on silicone rubber voice prostheses in vitro.

The proliferation of yeasts in the mixed bacterial and fungal biofilms colonising silicone rubber voice prostheses in laryngectomised patients is the main cause of malfunctioning of the valve mechanism on the oesophageal side of the prostheses. Indwelling voice prostheses usually have to be replaced every 3-4 months. The consumption of probiotic bacteria is largely motivated by health claims related to the urogenital and lower digestive tract, but not to the upper digestive tract. The present study examined the influence of probiotic bacteria on the prevalence of yeasts in oropharyngeal biofilms on silicone rubber voice prostheses, as formed in a modified Robbins device. Exposure of oropharyngeal biofilms on voice prostheses to suspensions of Bifidobacterium infantis 420 or Enterococcus faecium 603 did not significantly reduce the number of yeasts in the biofilm. However, suspensions of Lactobacillus fermentum B54, L. rhamnosus 744 or L. lactis cremoris SK11 led to a reduction in the number of yeasts harvested from the voice prostheses. Suspensions of L. casei Shirota and Streptococcus thermophilus B significantly reduced the number of yeasts in the biofilm to 39% and 33%, respectively. The reduction brought about in yeast prevalence in the mixed biofilm was greatest by exposure to a suspension of L. lactis 53, with yeast prevalence only 4% of the control. In conclusion, the study demonstrated that the prevalence of yeasts in oropharyngeal biofilms on silicone rubber voice prostheses might be controlled by consumption of probiotic bacteria.

Preliminary observations on influence of dairy products on biofilm removal from silicone rubber voice prostheses in vitro.

We determined oropharyngeal biofilm removal from silicone rubber voice prostheses in an artificial throat after perfusion with different commercially available dairy products, including buttermilk, Lactobacillus casei Shirota fermented milk (Yakult, Yakult Netherlands BV, Almere, The Netherlands), low-fat milk, and three types of yogurt. Buttermilk removed both yeasts and bacteria from biofilms on voice prostheses, but this was not observed with a pasteurized buttermilk product. Some of the other products, most notably Yakult fermented milk drink, reduced the number of bacteria, whereas growth of yeasts in the biofilms was not inhibited. This study demonstrates that there may be health benefits associated with the consumption of certain dairy products when applied to the upper digestive tract.

Biofilm formation on voice prostheses: influence of dairy products in vitro.

Laryngectomized patients use silicone rubber voice prostheses to regain their speech, however, the lifetime of these devices is limited due to biofilm formation. Following anecdotal evidence, the influence of various dairy products on biofilm formation on voice prostheses was studied, using the artificial throat-model. Biofilms were grown on Groningen and Provox2 voice prostheses by inoculating two artificial throats with the total microflora isolated from an explanted Groningen voice prosthesis. After 3 days, one throat was perfused three times daily with 650 ml dairy product; the other was perfused with phosphate buffered saline, used as a control. After 12 days the microflora on each voice prosthesis was determined. Perfusion of the artificial throat with buttermilk three times daily for 9 days reduced the amount of bacteria and yeasts in the biofilm on Groningen voice prostheses to 3% and 15% of the control, respectively. These effects were not observed with a pasteurized conservable buttermilk product. Yakult fermented milk drink, Mona mild yoghurt, Mona vifit yoghurt, semi-skimmed milk and low-fat yoghurt reduced the amount of bacteria by various degrees, ranging from 12% (Yakult) to 88% (Mona mild) of the control, but these products did not inhibit, and sometimes even stimulated, yeast growth. A combination of buttermilk and Yakult did not show a synergistic effect, as expected. Effects for the Provox2 voice prosthesis were less pronounced. These in vitro experiments in the artificial throat demonstrated that the formation of the biofilm on voice prostheses can be lessened by the daily use of certain dairy products, of which buttermilk had the strongest inhibitory effect, followed by Yakult.