The relationship between the tympanostomy tube extrusion time and viscosity

OBJECTIVE

The purpose of the study was to assess the correlation between the tympanostomy tube extrusion time and the viscosity of the middle ear fluid.

METHODS

Thirty-three patients who were scheduled for a tympanostomy tube (TT) insertion were included in the study. During the paracentesis procedure, fluid from the middle ear was obtained, and the viscosity was measured with a viscometer. Patients with effusion values below and above the median viscosity value of 439 cP (cP) were assigned to Group 1 and Group 2, respectively. After the surgery, the patients were followed up monthly until the tubes were observed to be extruded.

RESULTS

The analysis of the correlation between the tube extrusion time and the viscosity was statistically insignificant (p > 0.05). The mean tube extrusion time of Group 1 (12.65 ± 4.152 months) was slightly lower than that of Group 2 (13.81 ± 4.43 months); however, the difference was not statistically significant.

CONCLUSION

The tube extrusion time can be longer or shorter and is independent of the effusion viscosity. Further studies are needed to clarify the factors that affect the TT extrusion time.

TRIAL REGISTRATION NUMBER

NCT03848026.

Tympanostomy Tube Innovation: Advances in Device Material, Design, and Office-Based Technology

OBJECTIVES

With tympanostomy tube insertion remaining the most common procedure performed in children to date, growing interests in minimizing both procedural costs and anesthetic exposure in the pediatric population have inspired innovation with respect to tympanostomy tubes. As such, we aim to discuss the current state of tympanostomy tube innovation including insertion devices, tube material, and design.

METHODS

Computerized literature review.

RESULTS

(1) Numerous single-use devices consisting of a myringotomy knife and preloaded tympanostomy tube offer potential advantages of decreasing or eliminating operating room time and may be performed under moderate instead of a general anesthetic. (2) Innovation with respect to tympanostomy tube material and design may offer enhanced ototopical drug delivery, decreased rates of tube occlusion, and/or the ability to dissolve "on-command" with application of a novel ototopical material. (3) These technologies currently remain in various phases of preclinical and clinical testing.

CONCLUSIONS

While clinical testing for a number of new technologies is preliminary and ongoing, tympanostomy tube-related innovations hold exciting promise to supplement or potentially replace the present-day armamentarium of tympanostomy tube design and insertion moving forward.

What's New with Tubes, Tonsils, and Adenoids?

Evidence-based recommendations are constantly being updated for various pediatric surgical procedures, including the role for tympanostomy tubes, as well as indications for adenoidectomy and tonsillectomy. With a growing body of research available on some of the most prevalent pediatric conditions, an update on the current concepts surrounding management is warranted.

A randomized study of four different types of tympanostomy ventilation tubes - Full-term follow-up

OBJECTIVE

To evaluate the impact of tympanostomy ventilation tube material (silicone vs fluoroplastic) and shape (short vs long) regarding time to extrusion, occurrence of otorrhea, occlusion, tube removal and occurrence of persistent perforation.

METHODS AND MATERIAL

Four different types of ventilation tubes were used; Long Armstrong tubes, Donaldson tubes, Shepard tubes and straight tubes, representing four specific combinations of VT material (silicone or fluoroplastic) and shape (short, double flanged or long, single flanged). Four hundred children scheduled for bilateral tube insertion were included in a randomized trial. The patients received one type of tube in the right ear and another type in the left ear. The incidence of tube extrusion and complications were monitored postoperatively every third month by an otolaryngologist.

RESULTS

Twenty-two children were excluded during surgery. Out of the studied 378 children the mean age was 35.3 months. 63.8% were boys. Short tubes extruded earlier than long tubes; hazard ratio (HR) 4.84 (95% CI 3.50-6.69, p < 0.001). Long Armstrong tubes were least prone to extrude. Silicone tubes resulted in significantly longer time to first infection in a VT ear, HR 1.68 (95% CI 1.03-2.76, p = 0.039). Donaldson tubes rendered the longest mean time to first infection (p = 0.025). Infections did not affect tube extrusion rates significantly (p = 0.879). No significant differences were found regarding tube occlusion, tube extraction or persistent perforation.

CONCLUSIONS

Long tubes are less prone to extrude early. Long Armstrong tubes have the least propensity to extrude early. Silicone tubes render significantly longer time to first infection. Donaldson tubes result in least infections. Infection does not affect extrusion rates significantly.

LEVEL OF EVIDENCE

1b.

[Quality of Life of Children with Otitis Media and Impact of Insertion of Transtympanic Ventilation Tubes in a Portuguese Population]

INTRODUCTION

Quality of life is an important measure for health-outcome evaluation. Although otitis media is one of the most common childhood diseases, its impact on Portuguese children's quality of life is unknown. The aim of this study is to determine the quality of life of Portuguese children with chronic otitis media with effusion and/or recurrent acute otitis media and the short-term impact of transtympanic ventilation tubes, using the Portuguese version of the OM-6 questionnaire, a valid, reliable and sensitive instrument to evaluate the health-related quality of life in children with otitis media.

MATERIAL AND METHODS

This study was conducted in a tertiary referral center, to where children are referred from primary care and hospital pediatric consultations. The Portuguese version of the OM-6 questionnaire was applied to children with chronic otitis media with effusion and/or recurrent acute otitis media. The instrument was re-administered at two months postoperatively to a group of children who underwent tympanostomy tube placement, to evaluate the change in quality of life with the surgical procedure.

RESULTS

The study involved a sample of 169 children, aged between 6 months and 12 years (mean: 4.20 ± 2.05 years). The average score in the survey was 3.3 ± 1.47, of a maximum of 7 (worst quality of life). The domains 'caregiver concerns', 'hearing loss' and 'physical suffering' had the highest scores. The domain 'hearing loss' was correlated with the domain 'speech impairment' (rs = 0.41; p < 0.001) and the domain 'physical suffering' correlated with the domain 'activity limitation' (rs = 0.47; p < 0.001). There was a correlation between the score on 'hearing loss' and the presence of conduction hearing loss (χ2 (6) = 24.662; p = 0.022). Children with chronic otitis media with effusion had lower scores on the domain 'physical suffering', while children with recurrent acute otitis media had lower scores in the domain 'hearing loss' and higher scores in the domain 'emotional distress'. There was an improvement in the quality of life in all the dimensions studied by the questionnaire after surgery. The improvement was large in 55%, moderate in 15% and small in 10% of the cases. The presence of otorrhea postoperatively did not decrease the quality of life improvement achieved with surgery.

CONCLUSION

Otitis media has a negative impact on Portuguese children quality of life. Tympanostomy tubes improve quality of life related to the middle ear in most children. The application of validated disease-specific questionnaires allows an enhanced understanding of the impact of otitis media on Portuguese children quality of life and of the success of therapeutic measures.

Subannular T-tubes for the treatment of adhesive otitis: how we do it

Subannular T-tubes for the treatment of adhesive otitis: how we do it.

OBJECTIVES

Adhesive otitis is a chronic otitis media (OM) that consists of the adhesion of the tympanic membrane (TM) to the promontory. The aim of our study is to evaluate a new way of positioning subannular T-tubes (SATs) in patients affected by adhesive otitis.

METHODOLOGY

This study enrolled 22 patients (average age: 36.7 yo, 2.5 SD; M/F ratio: 14/8) affected by unilateral chronic adhesive otitis. All of the patients underwent the positioning of a SAT and a Silastic@ sheet in the tympanic cavity. The clinical course was evaluated, considering otoscopic and audiological variations.

RESULTS

In our series, only one case of extrusion of tubes with residual perforation of TM was recorded. Auditory outcomes were satisfying in 18/22 patients (81.8%).

CONCLUSIONS

The proposed addition of a Silastic disk seems to avoid a new adhesion of the tympanic membrane to the promontory and, therefore, prevents treatment failures. A longer follow-up and a larger case series are needed to prove the efficacy of this surgical variation. Finally, the positioning of SATs can be considered as a valid and safe procedure for the treatment of adhesive otitis.

[Bacteriologic investigation of the Eustachian tube and the implications of perioperative antibiotics before balloon dilation]

BACKGROUND

Balloon Eustachian Tuboplasty (BET) is a new minimally invasive treatment for chronic Eustachian tube dysfunction (ETD). Initially, perioperative prophylactic antibiotic therapy with ciprofloxacin 2 × 500 mg p.o. for 5 days was administered. This study aimed to characterize the bacterial flora in the ET, nose, and pharynx in patients with chronic obstructive ETD. Additionally, we investigated the necessity of perioperative antibiotic prophylaxis in BET patients.

PATIENTS AND METHODS

We examined 40 patients undergoing BET: 20 patients with and 20 patients without perioperative antibiotic prophylaxis. All patients were followed-up for clinical signs and symptoms of local infection for at least 2 weeks after surgery. Following BET, the tips of 35 balloon catheters, as well as swabs from the nose and pharynx were sent for microbiologic analysis.

RESULTS

None of these 40 patients had postoperative signs of infection. Of the swabs of the balloon catheters, 46% were sterile and 23% showed standard flora. The remaining 31% of swaps revealed specific bacteria. However, none of the nasal or nasopharyngeal swaps were sterile.

CONCLUSION

Due to the lack of signs of postoperative infection in either investigated group, the authors no longer favor use of perioperative antibiotic prophylaxis in patients undergoing BET. The relevance of biofilms and pathogen colonization to ET function has recently been intensively discussed, and should be further investigated in future studies.

Resorption Rate and Biocompatibility Characteristics of Two Polyester Ventilation Tubes in a Guinea Pig Model

OBJECTIVES: Determine the resorption rate and biocompatibility characteristics of 2 polyester ventilation tubes, and to determine whether soap and water exposure accelerates polyester tube degradation.

STUDY DESIGN AND SETTING: 50/50 poly (D, L-lactide-co-glycolide; PLGA-50) and poly (L-lactide; PLA) polymers were placed into the tympanic membranes of Hartley pigmented guinea pigs. Integrity of the tubes was determined by weekly otoscopic examination. Biocompatibility was assessed by comparing auditory brainstem response (ABR) thresholds and by examining tympanic membrane changes following tube resorption. Shah minigrommet ventilation tubes were used as controls. In the second portion of this study, implanted PLGA-50 and PLA tubes were exposed weekly to a mixture of soap and water (1:5) until complete resorption was observed. Biocompatibility was assessed by periodic ABR testing and tympanic membrane examination.

RESULTS: The PLA tubes remained in the tympanic membrane for a longer period (63.2 ± 19.3 days) than the PLGA-50 (18.8 ± 8.1 days). The tympanic membrane and resorbable tube interface demonstrated equivalent findings for auditory thresholds and tissue histopathology at the implant site compared to nonresorbable controls. The resorption behavior was not altered by exposure to soap and water. Tympanic membranes of all animals following tube degradation and soap water exposure were intact with minimal scarring and no signs of persistent foreign body response. The histological analysis showed that implantation of resorbable tubes was not accompanied by secondary infection with otorrhea through the tube, did not result in a permanent perforation or dislocation of the tube into the middle ear cavity, and was not followed by excess tympanosclerosis or localized or diffuse membrane atrophy.

CONCLUSIONS AND SIGNIFICANCE: Resorbable polyester pressure equalization tubes demonstrate predictable resorption behavior and similar bio-compatibility characteristics when compared with nonresorbable Shah minigrommet ventilation tubes. Exposure to soap water does not accelerate polyester tube degradation nor change the host tissue response during the indwelling period or after complete resorption. The data suggests that resorbable ventilation tubes are substantially equivalent to other FDA-approved tympanostomy devices with regard to safety and biocompatibility in the guinea pig model examined and may provide improved clinical performance by combining this approach with sustained release technology. EBM rating: B-2.

Opening plugged tympanostomy tubes: Effect of inner diameter and shaft length

OBJECTIVE: To determine whether tympanostomy tube (TT) inner diameter or shaft length impacts the rate of mucoid plug clearance.

STUDY DESIGN AND SETTING: Ex vivo model. Silicone TTs with different inner-diameters (ID) and shaft-length (SL) pairings (1.14 mm ID × 12 mm SL versus 1.14 mm ID × 1 mm SL; 1.14 mm ID × 4.8 mm SL versus 1.32 mm ID × 4.8 mm SL) were plugged with middle-ear mucus (n = 15 per group) and placed in a model ear chamber. Ofloxacin otic solution was instilled into the chamber to cover the plugged TT, and the time to clearance of each plug was recorded.

RESULTS: TTs with larger IDs ( P = 0.019) and greater SLs ( P = 0.033) cleared plugs more rapidly. However, the difference in the percentage of tubes that unplugged was not significant ( P = 0.151).

CONCLUSIONS: Rate of ex vivo TT plug clearance may be altered by changing TT ID and SL.

Opening Plugged Tympanostomy Tubes: Effect of Biofilm Formation

OBJECTIVES: To determine if the presence of a bacterial biofilm impacts the rate of clearing of mucoid plugs from tympanostomy tubes (TTs).

STUDY DESIGN AND SETTING: Ex vivo model. Stainless steel Reuter Bobbin TTs ( n = 18) were placed in growth medium with Pseudomonas aeruginosa and Streptococcus pneumoniae for 12 days to promote biofilm formation. Tympanostomy tubes ( n = 18) placed in growth medium, without bacteria, for 12 days served as controls. Biofilm formation was assessed by scanning electron microscopy. All TTs were filled with middle ear mucus and allowed to dry, thereby forming a plug. TTs were placed in a model ear chamber, covered with ofloxacin otic solution, and the time to clear each plug was recorded.

RESULTS: Biofilm formation was consistently encountered on TTs exposed to bacteria but in no TTs in the control group. There was a significant effect of the biofilm on plug clearance, favoring TTs without a biofilm ( P = 0.0333). Although there was no significant difference in the proportion of unplugged TTs ( P = 0.264), TTs with a biofilm did not clear plugs as rapidly as TTs without a biofilm ( P = 0.0416).

CONCLUSIONS: The presence of a biofilm may slow the time to clear mucoid TT plugs, but it does not seem to affect the overall proportion of TTs that are unplugged.

Water precautions for prevention of infection in children with ventilation tubes (grommets)

BACKGROUND

Following middle ear ventilation tube (tympanostomy tube or grommet) insertion, most surgeons advise that a child's ears should be kept dry during the immediate postoperative period. Following the initial period some surgeons will permit swimming or bathing, whereas other surgeons will recommend ongoing water precautions. A large number of studies have been conducted to explore the association between water exposure and ear infections in children with ventilation tubes, however a range of differing conclusions exist regarding the need for water precautions and there is wide variation in clinical practice.

OBJECTIVES

To assess the effectiveness of water precautions for the prevention of ear infections in children with ventilation tubes (grommets), at any time while the tubes are in place.

SEARCH METHODS

The Cochrane ENT Trials Search Co-ordinator searched the ENT Trials Register; Central Register of Controlled Trials (CENTRAL 2015, Issue 8); PubMed; EMBASE; CINAHL; Web of Science; Clinicaltrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 1 September 2015.

SELECTION CRITERIA

Randomised controlled trials recruiting children (0 to 17 years) with ventilation tubes and assessing the effect of water precautions while the tubes are in place. We considered all forms of water precautions, including behavioural (i.e. avoidance or swimming/bathing restrictions) and mechanical (ear plugs/moulds or hats/bands).

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcome measures were episodes of otorrhoea and adverse effects; secondary outcomes were antimicrobial prescriptions for ear infections, ventilation tube extrusion, surgical intervention to remove ventilation tubes and hearing outcomes.

MAIN RESULTS

Two randomised controlled trials recruiting a total of 413 patients met the criteria for inclusion in our review; one study had a low risk of bias and the other study had a high risk of bias. Ear plugs versus control One study recruited 201 children (aged six months to six years) who underwent myringotomy and ventilation tube insertion. The study compared an intervention group who were instructed to swim and bathe with ear plugs with a control group; the participants were followed up at one-month intervals for one year. This study, with low risk of bias, showed that the use of ear plugs results in a small but statistically significant reduction in the rate of otorrhoea from 1.2 episodes to 0.84 episodes in the year of follow-up (mean difference (MD) -0.36 episodes per year, 95% confidence interval (CI) -0.45 to -0.27). There was no significant difference in ventilation tube extrusion or hearing outcomes between the two study arms. No child required surgical intervention to remove ventilation tubes and no adverse events were reported. Water avoidance versus control Another study recruited 212 children (aged three months to 12 years) who underwent myringotomy and ventilation tube insertion. The study compared an intervention group who were instructed not to swim or submerge their heads while bathing with a control group; the participants were followed up at three-month intervals for one year. This study, with high risk of bias, did not show any evidence of a reduction or increase in the rate of otorrhoea (1.17 episodes per year in both groups; MD 0 episodes, 95% CI -0.14 to 0.14). No other outcomes were reported for this study and no adverse events were reported. Quality of evidence The overall quality (GRADE) of the body of evidence for the effect of ear plugs on the rate of otorrhoea and the effect of water avoidance on the rate of otorrhoea are low and very low respectively.

AUTHORS' CONCLUSIONS

The baseline rate of ventilation tube otorrhoea and the morbidity associated with it is usually low and therefore careful prior consideration must be given to the efficacy, costs and burdens of any intervention aimed at reducing this rate.While there is some evidence to suggest that wearing ear plugs reduces the rate of otorrhoea in children with ventilation tubes, clinicians and parents should understand that the absolute reduction in the number of episodes of otorrhoea appears to be very small and is unlikely to be clinically significant. Based on the data available, an average child would have to wear ear plugs for 2.8 years to prevent one episode of otorrhoea.Some evidence suggests that advising children to avoid swimming or head immersion during bathing does not affect rates of otorrhoea, although good quality data are lacking in this area. Currently, consensus guidelines therefore recommend against the routine use of water precautions on the basis that the limited clinical benefit is outweighed by the associated cost, inconvenience and anxiety.Future high-quality studies could be undertaken but may not be thought necessary. It is uncertain whether further trials in this area would change the findings of this review or have an impact on practice. Any future high-quality research should focus on determining whether particular groups of children benefit more from water precautions than others, as well as on developing clinical guidelines and their implementation.

Extending Myringotomy Patency with Topical Everolimus in Rats

BACKGROUND

Everolimus is an immunosuppressant agent that has antiproliferative properties and negative effects on wound healing. The effect of everolimus use to delay the closure time of myringotomy is not known.

OBJECTIVES

The aim of the study was to evaluate the impact of topical everolimus on myringotomy patency and to investigate its histopathologic effects on the tympanic membrane.

MATERIAL AND METHODS

Twenty Sprague-Dawley rats were bilaterally myringotomized with a myringotomy knife. Gelfoam soaked in 0.05% everolimus in a microemulsion formulation was applied to the right myringotomy site of the rats for 10 min (the everolimus group). The myringotomy sites of the left ears were treated with sterile saline topically (the control group). The tympanic membranes were routinely examined otomicroscopically every other day for 31 days. The membranes were then harvested and evaluated histologically after 31 days.

RESULTS

All tympanic membranes were closed by the 15(th) day in the control group, while in the everolimus group the myringotomy remained open in five rats (25%) on day 31. The mean durations of myringotomy patency in the everolimus group and control group were 20.90 ± 7.85 and 10.10 ± 3.14 days, respectively. The difference was found to be statistically significant (p < 0.01). In the histopathological examination of the tympanic membranes, there was less fibrosis and less inflammation in the everolimus group than in the control group (p < 0.01).

CONCLUSIONS

Topical everolimus application is effective in extending myringotomy patency in rat tympanic membranes. Inflammatory reactions and fibrosis in the lamina propria were observed to be significantly less when topical everolimus was used.

Sonotubometry, a useful tool for the evaluation of the Eustachian tube ventilatory function

From the three Eustachian tube (ET) functions: middle ear protection, secretion clearance and middle ear ventilation, the ventilatory function is unanimously considered the most important one, because proper hearing is established only when tympanic membrane compliance is normal. This requires equilibrium between the middle ear and ambient gas pressure, which makes the normal functioning of active ET opening of critical importance. There are several methods and tests that can assess such a complex and variable mechanism. Sonotubometry is one such method; despite the fact that it has been continuously improved in the last 20 years, it is not yet systematically used to evaluate the ET ventilatory function, because its measurement pattern, context mapping (patient, clinic data, medication, treatment), validation, reproducibility and value for clinic practice, have not yet been fully consolidated and integrated in a knowledge-based, service-oriented system, that can provide decision support or even diagnostic. The paper reviews the role of tubal sonometry as a non-invasive, physiologic and easy to use method in assessing the ventilatory function and investigates the validity and reproducibility of a measuring pattern and test in a group of children. The paper describes the test pattern used, and the computer-based platform based on: (1) Digital Signal Processing (DSP) for sound acquisition and low-level processing; (2) Artificial Intelligence techniques to extract significant sound features from sonotubograms and learn a manifold context database. Results are reported from test series carried out in healthy children; a similar study between tests is included in the final Discussions section.

The protective effect of adenoidectomy on pediatric tympanostomy tube re-insertions: a population-based birth cohort study

OBJECTIVES

Adenoidectomy in conjunction with tympanostomy tube insertion for treating pediatric otitis media with effusion and recurrent acute otitis media has been debated for decades. Practice differed surgeon from surgeon. This study used population-based data to determine the protective effect of adenoidectomy in preventing tympanostomy tube re-insertion and tried to provide more evidence based information for surgeons when they do decision making.

STUDY DESIGN

Retrospective birth cohort study.

METHODS

This study used the National Health Insurance Research Database for the period 2000-2009 in Taiwan. The tube reinsertion rate and time to tube re-insertion among children who received tympanostomy tubes with or without adenoidectomy were compared. Age stratification analysis was also done to explore the effects of age.

RESULTS

Adenoidectomy showed protective effects on preventing tube re-insertion compared to tympanostomy tubes alone in children who needed tubes for the first time (tube re-insertion rate 9% versus 5.1%, p = 0.002 and longer time to re-insertions, p = 0.01), especially those aged over 4 years when they had their first tube surgery. After controlling the effect of age, adenoidectomy reduced the rate of re-insertion by 40% compared to tympanostomy tubes alone (aHR: 0.60; 95% CI: 0.41-0.89). However, the protective effect of conjunction adenoidectomy was not obvious among children with a second tympanostomy tube insertion. Children who needed their first tube surgery at the age 2-4 years were most prone to have tube re-insertions, followed by the age group of 4-6 years.

CONCLUSIONS

Adenoidectomy has protective effect in preventing tympanostomy tube re-insertions compared to tympanostomy tubes alone, especially for children older than 4 years old and who needed tubes for the first time. Nonetheless, clinicians should still weigh the pros and cons of the procedure for their pediatric patients.

Inhibition of otopathogenic biofilms by organoselenium-coated tympanostomy tubes

IMPORTANCE

Tube occlusion and post-tympanostomy tube otorrhea (PTTO) are 2 major sequelae of tympanostomy tube placement. Plugging negates the function of the tympanostomy tubes and, along with chronic PTTO, can be financially burdensome owing to repeated surgical procedures and additional treatments.

OBJECTIVE

To investigate the effectiveness of an organoselenium (OSe) coating on Donaldson tympanostomy tubes in inhibiting biofilm formation on the tympanostomy tubes.

DESIGN

In vitro microbiologic study; all experiments were performed in a Texas Tech University Health Sciences Center basic sciences laboratory.

INTERVENTIONS

Inhibition of biofilm formation was investigated by incubating OSe-coated vs uncoated (control) tympanostomy tubes in a nutrient broth containing either Staphylococcus aureus (Sa) expressing green fluorescent protein (GFP), nontypeable Haemophilus influenzae (NTHi) expressing GFP, or Moraxella catarrhalis (Mc) for 48 hours at 37 °C. All biofilms were quantified via colony-forming unit (CFU) assays. The Sa and NTHi biofilms were visualized using confocal laser-scanning microscopy (CLSM) and analyzed using the COMSTAT program.

MAIN OUTCOMES AND MEASURES

The CFU assays, CLSM, and COMSTAT analysis revealed that compared with uncoated control tympanostomy tubes, OSe-coated tympanostomy tubes are able to inhibit Sa, NTHi, and Mc biofilm formation.

RESULTS

The Sa and NTHi developed thick mature biofilms containing considerable biomass on uncoated tympanostomy tubes as determined by CLSM and COMSTAT analysis, while the OSe coating on the tympanostomy tubes drastically inhibited biofilm formation by Sa and NTHi. Quantitative CFU analysis revealed that this reduction in biofilm formation was significant, 6 logs for Sa (P < .001) and 4 logs for NTHi (P = .02). OSe coating also inhibited biofilm formation by Mc with a 4.5-log reduction (P < .001).

CONCLUSIONS AND RELEVANCE

The OSe coating is a potential long-lasting agent to prevent biofilm development on tympanostomy tubes by otopathogens.

[Retrospective evaluation of short tympanostomy tubes efficacy in case of recurrent acute otitis media on an infant population]

INTRODUCTION

The aim of this study is to appreciate the results of short-tympanostomy tubes (ST) in case of recurrent acute otitis media (AOM), and to appreciate the risk factors of recurrent AOM.

METHODS

This retrospective chart study concerns infants who had STT placement surgery forrecurrent AOM, between 2007 and 2011. Demographic data, anamnesis, efficacy and postoperative follow-up were analyzed.

RESULTS

Forty-nine children were included in the study (30 boys, 19 girls; 7 months to 2 years-old, median age 1.4 year). Two-thirds attended a day-care center, one third was an onlychild. One quarter had an anemia. Anti-Haemophilus and anti-pneumococcus vaccinations were up-to-date in 87.5%. After STT placement, 20 children (40.8%) did not present any new episode of AOM. This result did not vary with adenoidectomy. Among the ones that relapsed AOM after STT, 48.3% presented with only one episode. For two thirds of the patients, no general antibiotic treatment was necessary as long as the STT were in place. Half STT have been spontaneously expulsed between 6 and 12 months. Thirteen infants (37.1%) had new episodes of AOM after STT expulsion and 5 (38.5%) needed new tube placement.

CONCLUSION

This study confirms that day care and siblings are risk factors of recurrent AOM, but does not confirm potential role of the anemia. STT placement decreased effectively AOM recurrences, their severity and the need for antibiotics prescriptions. No residual perforation was encountered in this study.

Interventions for the prevention of postoperative ear discharge after insertion of ventilation tubes (grommets) in children

BACKGROUND

Grommets are frequently inserted in children's ears for acute otitis media and otitis media with effusion. A common complication is postoperative ear discharge (otorrhoea). A wide range of treatments are used to prevent the discharge, but there is no consensus on whether or not intervention is necessary nor which is the most effective intervention.

OBJECTIVES

To assess the effectiveness of prophylactic interventions, both topical and systemic, in reducing the incidence of otorrhoea following the surgical insertion of grommets in children.

SEARCH METHODS

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ICTRP and additional sources for published and unpublished trials. The date of the search was 3 July 2012.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared the efficacy of prophylactic interventions against placebo/control and/or with other prophylactic interventions for postoperative otorrhoea in children.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and risk of bias, and extracted data. The outcome data were dichotomous for all the included trials. We calculated individual and pooled risk ratios (RR) using the Mantel-Haenszel fixed-effect method. We also calculated the numbers needed to treat to benefit (NNTB).

MAIN RESULTS

We found 15 eligible RCTs (2476 children, aged from four months to 17 years). We graded seven RCTs as being at a low risk of bias (n = 926 children) and for an eighth RCT we also graded two of the arms as being at a low risk of bias. We graded the other seven trials as being at a high risk of bias.For a single application at surgery, there was evidence from two low risk of bias trials that at two weeks postoperatively the risk of otorrhoea was reduced by multiple saline washouts (from 30% to 16%; RR 0.52, 95% confidence interval (CI) 0.27 to 1.00; NNTB 7; one RCT; 140 children) and antibiotic/steroid ear drops (from 9% to 1%; RR 0.13, 95% CI 0.03 to 0.57; NNTB 13; one RCT; 322 ears). A meta-analysis of two low risk of bias trials (222 ears) failed to find an effect of a single application of antibiotic/steroid ear drops at four to six weeks postoperatively.For a prolonged application of an intervention, there was evidence from four low risk of bias trials that the risk of otorrhoea was reduced two weeks postoperatively by antibiotic ear drops (from 15% to 8%; RR 0.54, 95% CI 0.30 to 0.97; NNTB 15; one RCT; 372 children), antibiotic/steroid ear drops (from 39% to 5%; RR 0.13, 95% CI 0.05 to 0.31; NNTB 3; one RCT; 200 children), aminoglycoside/steroid ear drops (from 15% to 5%; RR 0.37, 95% CI 0.18 to 0.74; NNTB 11; one RCT; 356 children) or oral antibacterial agents/steroids (from 39% to 5%; RR 0.13, 95% CI 0.03 to 0.51; NNTB 3; one RCT; 77 children).Only one trial assessed the secondary outcome of ototoxicity, but no effect was found. There were no trials that assessed quality of life.

AUTHORS' CONCLUSIONS

Our review found that each of the following were effective at reducing the rate of otorrhoea up to two weeks following surgery: (1) multiple saline washouts at surgery, (2) a single application of topical antibiotic/steroid drops at surgery, (3) a prolonged application of topical drops (namely antibiotic ear drops, antibiotic/steroid eardrops or aminoglycoside/steroid ear drops) and (4) a prolonged application of oral antibacterial agents/steroids. However, the rate of otorrhoea between RCTs varied greatly and the higher the rates of otorrhoea within a RCT, the smaller the NNTB for therapy.We conclude that if a surgeon has a high rate of postoperative otorrhoea in children then either saline irrigation or antibiotic ear drops at the time of surgery would significantly reduce that rate. If topical drops are chosen, it is suggested that to reduce the cost and potential for ototoxic damage this be a single application at the time of surgery and not prolonged thereafter.

[The assessment of the ventilation function of the eustachian tubes after shunting of the tympanic cavity]

The objective of the present work was to study specific features of the eustachian tube after the insertion of the shunt into the tympanic membrane and to measure the pressure necessary to ensure passive opening of the tube in the patients presenting with exudative otitis medium (EOM). The study included 87 patients with this pathology who underwent shunting of the tympanic cavity following a course of conservative treatment. Threshold audimetry and acoustic impedancemetry were performed in all the patients to estimate the patency of the eustachian tube with the perforated tympanic membrane. It is concluded that the shunting of the tympanic cavity resulted in markedly disturbed dynamic function of the Eustachian tube in the majority of the patients (59%) regardless of the severity of hearing impairment.

Medial displacement of T-tubes: case report

Medial displacement of T-tubes is rare and only 6 cases have been reported in literature. We report a case of a medial displacement of a T-tube in the middle ear behind an intact tympanic membrane with normal mobility. No treatment was undergone as the patient was asymptomatic and no hearing problems were detected. A brief overview of this unusual complication of tympanostomy tubes is presented and the management strategy is discussed.

Extra-annular T tubes: a case series

OBJECTIVE

to review the efficacy of extra-annular T tubes in a cohort of patients.

DESIGN

case series of 50 patients undergoing 60 extra-annular T-tube insertions.

SETTING

district general hospital.

METHODS

retrospective review of case notes.

MAIN OUTCOME MEASURES

extrusion, chronic perforation after extrusion, infection, occlusion.

RESULTS

Sixteen of 60 tubes extruded at an average of 16 months after insertion. Two tubes had to be removed. One of 18 extruded/removed tubes was associated with a chronic perforation. Seven of 60 tubes became infected during the follow-up period, none of which required removal. Of the 42 tubes that did not extrude or have to be removed, the average follow-up was 23 months.

CONCLUSION

our case series of extra-annular tubes suggests that this procedure is a safe intervention for long-term middle ear ventilation with a low rate of infection and chronic perforation.

Interactive computer-based simulator for training in blade navigation and targeting in myringotomy

A virtual-reality simulator was developed for the training of Otolaryngology (Ear-Nose-Throat) surgical residents to perform myringotomy, a relatively common surgical procedure in which an incision is made in the eardrum mainly to treat middle-ear infections. The simulator presents the trainee with a three-dimensional (3D) virtual model of the ear that can be viewed through a mock surgical microscope consisting of a stereo visor mounted on a custom-designed stand. The trainee interacts with the virtual ear using a real myringotomy blade, the movements of which are tracked in real time using a stereo optical tracker. Interactions of the blade with virtual tissues are calculated and rendered on the visor using freely available physics and graphics software engines. Six experienced surgical residents and surgeons assessed the effectiveness of the simulator as a viable training tool by completing a questionnaire designed specifically for this study after using the simulator. Surgeons and residents were positively impressed by the simulator as a training tool and would recommend its use as part of training.

[Retaining time of tympanic ventilation tube and aural complications]

OBJECTIVE

To study the relationship of retaining time of tympanic ventilation tube and aural complications.

METHOD

Three-hundred-five patients(659 ears)with otitis media with effusion (OME) received tympanostomy tube insertion. The tube were removed 6-36 months after tube insertion. Then aural complications were recorded in different tube retaining time, followed with a statistic analysis.

RESULT

Fifty-five tubes of 29 patients were removed at 1-6 months after tube insertion, with spontaneous extrusion 3.4%, blocked tube 10.3%, intrusion into the middle ear 0, granulation tissue 0, cholesteatoma 0, otorrhea 6.9%, perforation 0. One hundred and ninety tubes of 96 patients were removed at 6-12 months after tube insertion , with spontaneous extrusion 7.3%, blocked tube 15.6%, intrusion into the middle ear 1%, granulation tissue 0, cholesteatoma 0, otorrhea 5.2%, perforation 0. Three hundred and eight tubes of 156 patients were removed at 12-24 months after tube insertion, with spontaneous extrusion 9%, blocked tube 12.8%, intrusion into the middle ear 1.3%, granulation tissue 1. 9%, cholesteatoma 0.6%, otorrhea 2.5%, perforation was 0. One hundred and sixty one tubes of 83 patients were removed at 24-36 months after tube insertion, with spontaneous extrusion 36.1%, blocked tube 53%, intrusion into the middle ear 6%, granulation tissue 3.6%, cholesteatoma 2.4%, otorrhea 2.4%, perforation 2.4%.

CONCLUSION

The occurrence of complication didn't increase with time going by when the ventilation tube retained less than two years. However, when the ventilation tube retained more than two years, the occurrence of spontaneous extrusion and blocked tube increased obviously.

Permanent t-tube insertion in two patients with Hurler's syndrome

Hearing loss in mucopolysaccharidosis is usually both conductive and sensorineural. The conductive component is attributable to serous otitis media secondary to dysfunction of the eustachian tube and chronic thickening of the mucosa of the middle ear. The conductive component may persist after myringotomy and insertion of short-term or long-term ventilation tubes. In Hurler's syndrome, death usually occurs in the first decade of life. In our study, we present two cases, a three-year-old girl and a four-year-old boy, who were diagnosed with Hurler's syndrome. Both children have a history of otitis media with effusion requiring repeated short-term ventilation tube insertions that were unsuccessful. Permanent t-tubes were inserted in both cases. Results showed an approximate 20 dB improvement in hearing sensitivity postoperatively for each patient.

[Tympanostomy tube placement in children with secretory otitis media: analysis of effects and complications]

INTRODUCTION AND OBJECTIVES

Tympanostomy tube emplacement is a common surgical procedure in paediatric otolaryngological surgery. This surgery has complications that sometimes depend on the disease and at other times on the treatment. The objective of this study is to know the results obtained with tympanostomy tube emplacement and its complications.

MATERIAL AND METHODS

Retrospective study of all the children operated on for tympanostomy tube emplacement over a period of 18 months and with follow-up for at least seven years; this amounted to 143 ears operated on for the first time. The study variables were age, gender, initial appearance of the ear, inner ear contents, type of grommet inserted, duration of grommet and the lack of any hospital monitoring needed after extrusion.

RESULTS

One complication or another arose in 46% of the ears. The Donaldson type of grommet with a diameter of 1.27 mm is the one that produced most complications. There were more complications in ears that were worse in the otoscopic examination regardless of the grommet inserted.

CONCLUSIONS

The high prevalence of complications and after-effects after grommet emplacement needs long-term follow-up in patients. The results obtained suggest the use of grommets with a smaller internal diameter.

Never trust secondary references: examples from the early history of myringotomy and grommets

The regular use of secondary references is associated with many inaccuracies. The aim of this study is to demonstrate this fact through examples extracted from recent papers mentioning the early history of myringotomy and grommets. These inaccuracies are in relation with the lack of control of the original references dealing with the subject. In conclusion, never believe and use secondary references as primary sources, without reading the original paper to confirm that it says what you think it does, but take them only for preparing and discussing the studied subject.

Phosphorylcholine-coated antibiotic tympanostomy tubes: are post-tube placement complications reduced?

OBJECTIVE

To determine if a phosphorylcholine (PC) antibacterial coating on standard Armstrong beveled tympanostomy tubes (TT) reduced the incidence of post-tube placement complications.

METHODS

A prospective cohort aged 8-51 months received bilateral TTs for otitis media with effusion between July 2002 and February 2004 at a tertiary care pediatric hospital. Seventy children were randomized to receive a PC-coated TT in one ear and an uncoated TT in the other. Otologic examinations at prescribed intervals over two years post-operatively ascertained the status of sequelae. We analyzed the incidence of TT complications: otorrhea, premature extrusion, persistent tympanic membrane perforations, granulation tissue, and ventilation tube lumen obstruction.

RESULTS

There was no statistical difference in the incidence of any of these sequelae between standard and PC-coated tympanostomy tubes (p>0.05) during the 24-month-follow-up period. Results after 13 months of follow-up may have been affected by patients lost to follow-up and therefore a smaller sample size as the study continued.

CONCLUSIONS

This study found that there is no statistically significant difference in the incidence of complications between uncoated and PC-coated fluoroplastic Armstrong beveled TTs.

Results of exploratory tympanotomy following sudden unilateral deafness and its effects on hearing restoration

In cases of acute unilateral deafness, no consensus exists as to whether tympanotomy and sealing of the round window should be performed routinely. To further address this issue, we conducted a retrospective study of pre-, intra-, and postoperative findings in 97 patients who had undergone exploratory tympanotomy (EXT) after the onset of sudden and severe unilateral deafness. Our goal was to ascertain, if we could, whether the benefits of EXT outweigh the risks. We also took into account the effects of perilymph fistula (PLF) on the etiology of sudden hearing loss and postoperative outcomes. We found that routine EXT was indeed beneficial for these patients. It was associated with a very low surgical complication rate, and its effects on hearing as assessed by objective measures were beneficial. The greatest benefits were seen in patients who underwent EXT within 7 days after the onset of their hearing loss. With respect to PLF, we found that the presence or absence of the "typical history" of PLF (i.e., a sudden unilateral hearing loss within 48 hours after a precipitating trauma or physical exertion) had no bearing on whether a PLF was actually present in our group; nor was vertigo a reliable predictor of PLF. We recommend that EXT be performed on all patients with new-onset acute unilateral deafness, barring any contraindications, of course. The absence of a typical history of PLF should not dissuade the surgeon from proceeding with EXT.

Pharmacokinetics of CIPRODEX otic in pediatric and adolescent patients

OBJECTIVE

Describe the pharmacokinetics of ciprofloxacin and dexamethasone after administration of CIPRODEX Otic Suspension (CIP/DEX) into the middle ears of children.

DESIGN

Open-label, single-dose, pharmacokinetic studies, administering four drops of CIP/DEX instilled into each middle ear through the tympanostomy tubes immediately following tube placement. Blood was collected for 6h and analyzed for ciprofloxacin and dexamethasone concentrations using a validated liquid chromatography and tandem mass spectrometry (LC/MS/MS) method.

SETTING

The study was conducted through a referral pediatric otolaryngology practice with actual surgical procedures performed in an ambulatory care center.

PATIENTS

Twenty-five randomly selected patients, 1-14 years of age (mean age, 5 years), receiving tympanostomy tubes.

RESULTS

Peak ciprofloxacin plasma levels were observed at about 1h, with a mean C(max) of 1.33+/-0.96 ng/mL (range <0.5-3.45 ng/mL) and an estimated half-life of 3.0+/-1.2h. Peak dexamethasone plasma levels were observed within 2h with a mean C(max) of 0.90+/-1.04 ng/mL (range <0.05-5.10 ng/mL) and an estimated half-life of 3.9+/-2.9h.

CONCLUSION

These results demonstrated low systemic exposure of ciprofloxacin and dexamethasone following topical otic administration in pediatric patients.

Improving the penetration of ototopicals through tympanostomy tubes: role of surfactants

OBJECTIVE

To evaluate the ability of surfactants to increase the penetration of ototopicals through tympanostomy tubes (TT).

METHODS

An in vitro model was used to test the penetration of ototopicals with and without two surfactants (docusate sodium and beractant) through fluoroplastic and titanium TTs. The model was created by placing a TT through a perforation (myringotomy) in a model of the tympanic membrane (silastic sheet) fixed between the ends of two 1 mL syringes. Measurements were recorded of the maximum height various solutions (distilled water, soapy water, ofloxacin otic, ciprofloxacin/dexamethasone otic) achieved before penetrating the TTs (1.27 mm Reuter Bobbin titanium, 1.27 mm fluoroplastic). These same measurements were then performed with the addition of docusate sodium or beractant to the distilled water and each of the ototopical solutions.

RESULTS

The addition of docusate sodium significantly increased the penetration of water and ofloxacin otic through both types of TTs. It significantly increased penetration of ciprofloxacin/dexamethasone otic through fluoroplastic tubes with a trend towards increased penetration through titanium tubes. Adding beractant showed a modest trend toward increasing the penetration of both ototopicals in fluoroplastic tubes which did not reach statistical significance.

CONCLUSIONS

These results demonstrate that the penetration of ototopicals through TTs can be improved by the addition of surfactants. Increasing the penetration of ototopicals may make them more effective in treating TT otorrhea. However, we strongly discourage clinicians from using these compounds clinically until their safety has been established.

[Treatment of chronic tube dysfunction. Use of the tube conductor]

BACKGROUND

Chronic tube dysfunction plays a major part in the development of chronic otitis media. Owing to the complex structure of the Eustachian tube, the development of successful therapeutic approaches to the treatment of tube function disorders is still difficult even today. The application of a gold tube wire (tube conductor) was reported in 1991, but no studies have yet been performed on the postoperative success rates achieved with tube conductors.

MATERIAL AND METHODS

In a retrospective study, the data relating to 125 patients who were operated on from 1996 to 1999 for treatment of different forms of chronic otitis media and also underwent transtympanic tube conductor implantation to improve tube ventilation disorder were evaluated. Data on pre- and postoperative tube function were available for 96 patients after a mean follow-up period of 18 months.

RESULTS

All tube implantations were achieved without complications. Tube function normalized in 8 patients (8.3%), while the tube ventilation disorder remained unaffected in 88 patients (91.7%). A total of 23 (18.4%) tube conductors have so far been removed. The reasons for removal include persistent tube ventilation disorder, dislocation of the tube conductor in 7 patients (5.6%) and granulation around the tube wire in 7 cases (5.6%).

CONCLUSIONS

The chronic tube ventilation disorder was improved by implantation of a tube conductor in only 8.3% of the patient population investigated. We are therefore of the opinion that this is not a suitable treatment for chronic tube ventilation disorders. The development of new, effective therapeutic approaches to the treatment of chronic tube ventilation disorders remains a priority.

Antibacterial effect of tea-tree oil on methicillin-resistant Staphylococcus aureus biofilm formation of the tympanostomy tube: an in vitro study

The antibacterial effects of tea-tree oil against the formation of methicillin-resistant Staphylococcus aureus (MRSA) biofilm on the surface of the tympanostomy tubes was evaluated.

MATERIALS AND METHODS

Silicone tympanostomy tubes were pretreated with normal saline for 12 hours, the control group (n=4), with 100% tea-tree oil, experimental group A (n=3), or with 50% tea-tree oil, experimental group B (n=3). All the tubes were incubated in a MRSA solution for 2 days and then processed for evaluation using scanning electron microscopy.

RESULTS

The development of the biofilm mode of growth of MRSA was observed in the saline-treated control group. In contrast, only focal biofilms were present on the tube surface in experimental group A and considerable reduction of biofilm with destruction of the MRSA cells was shown in experimental group B.

CONCLUSION

From these results, the antimicrobial effect of tea-tree oil against biofilm formation on tympanostomy tubes in vitro has been verified.

The effect of early insertion of grommets on the development of speech in children with cleft palates

The aim of this study was to find out whether simultaneous primary palatoplasty and myringotomy was advantageous in the management of otitis media with effusion in children with cleft lip and palate and whether this combined operation resulted in improvement in the early development of speech. Assessments of hearing and speech were made in 50 consecutive patients with cleft lip and palate who had the combined operation (the cleft group). The results were compared with those of an age- and sex-matched control group. The incidence of otitis media with effusion in the cleft group was 24%, compared with 14% in the control group. Assessment of speech using the cleft audit protocol for speech showed that 90% of patients with clefts had speech-intelligibility ratings that were either normal or showed only minor defects, compared with 98% of controls. Among patients with clefts, there was no evidence of cleft-type characteristics of speech in 58%.

Five-year results for use of single-flanged tympanostomy tubes in children

AIMS

To assess the five-year outcome of the use of single-flanged tympanostomy tubes in children, including the time to extrusion, rate of retained tubes and rate of persistent perforation.

MATERIALS AND METHODS

The medical records relating to 640 single-flanged tympanostomy tubes intended for short-term use in paediatric patients were retrospectively reviewed.

RESULTS AND ANALYSIS

We found that 36.4 per cent of the tubes had extruded within 12 months and 71.0 per cent within 24 months. Results showed that 14.1 per cent of the tubes had been removed because of prolonged retention, with a mean time to removal of 38.9 months. The time to extrusion was longer and the rate of retained tubes was higher than those reported for several other short-term tubes. We found that 4.5 per cent of tube insertions had resulted in a persistent perforation, a higher percentage than previously reported for other tubes intended for short-term use. Within five years of tube insertion, 70.5 per cent of the tympanic membranes had normalised.

Factors of the blockage of ventilation tubes in the immediate postoperative period

Postoperative ventilation tube (VT) blockage is relatively common with a reported incidence of 0.0-13.1%. The purpose of this study was to evaluate the factors that contribute to postoperative VT blockage. A retrospective chart review was carried out to compare rates of VT blockage within 2 weeks postsurgery. Analyzed factors included: otic drop, nature, and amount of middle ear (ME) effusion, presence of ME mucosa edema or granulation, bleeding during surgery, number of prior VT insertion, and the status of the tympanic membrane (TM). One hundred and twenty-eight ears from 79 patients were enrolled in this study. Eleven VTs (8.6%) were obstructed within 2 weeks postsurgery. Ears using ciprobay and tarivid otic drops showed a significantly higher rate of tube blockage (14.1%) compared to ears that were not exposed to otic drops (1.8%). Glue effusion caused the highest rates (14.8%) of tube blockage compared to mucoid (9.6%) and serous (3.0%) effusions. The amount of effusion, the presence of mucosal edema or granulation, bleeding during surgery, number of prior VT insertions and the status of the TM were not associated with postoperative VT blockage. The results of this study suggest that the routine use of antibiotic-containing otic drops after the insertion of VT may not be useful. Viscosity of the effusion appears to have an effect on the postoperative VT blockage. Thus, more attention should be focused on the ears with glue or mucoid effusions after surgery.

Audit of the incidence of persistent perforation of the tympanic membrane following T-tube removal or extrusion

Audit of the incidence of persistent perforation of the tympanic membrane following T-tube removal or extrusion was carried out on 100 patients (151 ears). The incidence was found to be 11.9 per cent. This was independent of whether the tube was surgically removed or extruded; of the grade of surgeon carrying out the operation; and whether the patient treatment was carried out privately or on the N.H.S. Changes of practice have resulted from the audit.

Bacterial biofilm adherence to middle-ear ventilation tubes: scanning electron micrograph images and literature review

Introduction: The organisms that cause many device-related and other chronic infections actually grow in biofilms in or on these devices. We sought to examine the role of biofilm formation in chronic middle-ear ventilation tube infection.

Case report: Scanning electron micrograph images are presented which demonstrate biofilm on a middle-ear ventilation tube removed from a five-year-old child's chronically discharging ear. A review of the relevant international literature explores the role of biofilms in chronic infection and discusses potential intervention strategies.

Conclusion: Biofilms may be responsible for chronic middle-ear ventilation tube infection that resists treatment with conventional antibiotics.

The influence of ventilation tube design on the magnitude of stress imposed at the implant/tympanic membrane interface

The design of ventilation tubes or grommets is thought to have a considerable influence on their performance. A computational model (finite element method) was used to investigate the significance of four design parameters of a commonly used design of ventilation tube. The design parameters were: the length of the shaft, the diameter of the flanges, the thickness of the flanges, and the material type. A statistical analysis technique, known as a factorial analysis of variance, was used to examine the importance of the four design parameters on the dynamical behaviour of the middle ear with the implant in situ and on the magnitude of stress induced at the implant/tympanic membrane interface. We predicted that the ventilation tube alters the frequency response of the middle ear; specifically the shaft length and the thickness of the flanges were found to have a significant effect upon the vibratory pattern at the umbo. A reduced length of tube and an increased size of flange were also found to be significant for minimising membrane stress (both with P<0.001). Thus, design parameters of critical influence on optimising performance were identified.

Structural features of tympanostomy tube biofilm formation in ciprofloxacin-resistant Pseudomonas otorrhea

OBJECTIVE

Bacterial biofilm formation has been implicated in the high rate of persistent otorrhea after tympanostomy tube insertion. In this study, we evaluated Pseudomonal biofilm formation from intractable post tympanostomy tube otorrhea in children.

MATERIALS AND METHODS

Twelve patients (seven males, five females) with unilateral post tympanostomy tube P. aeruginosa otorrhea were evaluated prospectively. All patients were treated with ciprofloxacin otic drops but the otorrhea failed to resolve. Ear discharge for culture was collected from the external auditory canal using a swab. The tympanostomy tubes were removed and collected for evaluation of biofilm formation using a scanning electron microscopy.

RESULTS

In all cases, ciprofloxacin-resistant P. aeruginosa was the only organism grown. The surface of the silicone tube contained undulations or microfissures throughout. The thick biofilms present on most tube surfaces were densities with no intervening spaces, consistent with biofilms.

CONCLUSION

Biofilms can be directly observed by scanning electron microscopy. Therefore, our results demonstrate that bacterial aggregates called biofilms, that are resistant to treatment by antibiotics, can be detected by standard culture techniques, and may play a major etiologic role in posttympanostomy otorrhea.