Different Materials for Plugging a Dehiscent Superior Semicircular Canal: A Comparative Histologic Study Using a Gerbil Model.

HYPOTHESIS: The choice of the material for plugging a dehiscence of the superior semicircular canal is based on the ease of use and the success of the procedure to permanently relieve symptoms without adverse side effects. BACKGROUND: Dehiscence of the superior semicircular canal can lead to autophony, conductive hearing loss, and vertigo. Surgical treatment by plugging the canal is a highly effective treatment of the symptoms in many patients, although, the procedure can be associated with some degree of hearing loss in more than or equal to 25% of the patients. The available data indicate that adverse effects may be more frequently observed with bone wax as compared with other materials. METHODS: In the present study we compare the tissue reactions induced by plugging the superior semicircular canal with autologous bone pate/bone chips, muscle, fat, artificial bone wax, and teflon in the gerbil model in an attempt to identify the material leading to successful plugging with the least adverse tissue reactions. RESULTS: Our data show that successful plugging was achieved in 100% of the ears by bone pate/bone chips, teflon, and bone wax while the success rate was significantly lower (<50%) following muscle and fat. The proportion of adverse tissue reactions was significantly more pronounced using bone wax as compared with teflon and bone pate/bone chips. CONCLUSION: The use of teflon or autologous bone as a material for plugging a dehiscent superior semicircular canal should be favored over bone wax, muscle, and fat.

How to Avoid a Learning Curve in Stapedotomy: A Standardized Surgical Technique.

OBJECTIVE: To evaluate, whether a learning curve for beginners in stapedotomy can be avoided by using a prosthesis with thermal memory-shape attachment in combination with a standardized laser-assisted surgical technique. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Fifty-eight ears were operated by three experienced surgeons and compared with a group of 12 cases operated by a beginner in stapedotomy. INTERVENTION: Stapedotomy. MAIN OUTCOME MEASURES: Difference of pure-tone audiometry thresholds measured before and after surgery. RESULTS: The average postoperative gain for air conduction in the frequencies below 2 kHz was 20 to 25 dB and decreased for the higher frequencies. Using the Mann-Whitney-U test for comparing mean gain between experienced and inexperienced surgeons showed no significant difference (p = 0.281 at 4 kHz and p > 0.7 for the other frequencies). A Spearman rank correlation of the postoperative gain for air- and bone-conduction thresholds was obtained at each test frequency for the first 12 patients consecutively treated with a thermal memory-shape attachment prosthesis by two experienced and one inexperienced surgeon. This analysis does not support the hypothesis of a "learning effect" that should be associated with an improved outcome for successively treated patients. CONCLUSION: It is possible to avoid a learning curve in stapes surgery by applying a thermal memory-shape prosthesis in a standardized laser-assisted surgical procedure.

[Destruction of microsurgical devices by sterilisation]. / Schädigung von mikrochirurgischen Instrumenten durch Aufbereitung in einer Zentralsterilisation.

Hospital facilities issue numerous risk announcements on corrosion, deformation or premature wearout of medical devices every year. As there is yet little data on the impact of reprocessing on the quality and durability of microsurgical instruments, this paper aims at evaluating the effects of the reprocessing on microsurgical instruments. Material and Methods 22 brand new microsurgical instruments for stapes surgery were being reprocessed 30 times without being used for surgery or other purposes in the interim time. After each reprocessing the instruments were examined macroscopicly and microscopicly. The results were portrayed in a photo documentation and analysed on that basis. Results Almost all devices showed mechanical damage caused by the reprocessing procedure. The increasing deterioration was often associated with missing protective caps. Furthermore contaminations and stains were apparent in several cases. Conclusions The findings illustrate that careful handling of delicate surgical devices during reprocessing is vital. They also highlight problems of protective caps. As an alternative going forward it should be considered to store microsurgical instruments statically in special racks.

Behavioral auditory thresholds and loss of ribbon synapses at inner hair cells in aged gerbils.

The potential contribution of auditory synaptopathy to age dependent hearing loss was studied in groups of young and old gerbils. The analysis of the number of inner hair cell ribbon synapses in aged gerbils (37.9±3.3months of age) revealed only a relatively small (11-17%) loss in the basal two thirds of the cochlea, while a more pronounced reduction was identified towards the apex (almost 40%) when compared to a group of young gerbils (9.5±3.2months of age). Mean threshold elevation in the old gerbils was around 25dB at 2 and 10kHz. Frequency-specific behavioral thresholds and ribbon synapse counts were not significantly correlated for the middle and basal regions of the cochlea, despite thresholds varying over a 45dB SPL range. This suggests that besides a small age-dependent loss of ribbon synapses, additional cochlear pathologies, most likely a decreased endocochlear potential, contribute to peripheral hearing loss in old gerbils.

The Relevance of the High Frequency Audiometry in Tinnitus Patients with Normal Hearing in Conventional Pure-Tone Audiometry.

OBJECTIVE: The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz-8 kHz). Here we explored whether the results of the high frequency audiometry (>8 kHz) provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical characteristics. SUBJECTS AND METHODS: From the database of the Tinnitus Clinic at Regensburg we identified 75 patients with normal hearing thresholds in the conventional pure-tone audiometry. We contrasted these patients with normal and pathological high-frequency audiogram and compared them with respect to gender, age, tinnitus severity, pitch, laterality and duration, comorbid symptoms and triggers for tinnitus onset. RESULTS: Patients with pathological high frequency audiometry were significantly older and had higher scores on the tinnitus questionnaires in comparison to patients with normal high frequency audiometry. Furthermore, there was an association of high frequency audiometry with the laterality of tinnitus. CONCLUSION: In tinnitus patients with normal pure-tone audiometry the high frequency audiometry provides useful additional information. The association between tinnitus laterality and asymmetry of the high frequency audiometry suggests a potential causal role for the high frequency hearing loss in tinnitus etiopathogenesis.

Identification and genotype/phenotype correlation of mutations in a large German cohort with hearing loss.

The prevalence of hearing impairment is estimated as approximately 1 on 1,000 newborn children. To assess a higher mutation detection rate in individuals with hearing loss a three-step mutation screening program consisting of GJB2 in first line, then GJB1, GJB3 and GJB6 (second step) and if tested negative or heterozygote, testing of GJA1, GJB4, SLC26A4 and PJVK (third) was performed. Audiograms were derived from all patients to characterize audiological features of GJB2 mutations especially. In 59 patients (31.3%) of the 188 probands, the hearing impairment was due to GJB2 mutations, 45 (23.9%) of these being homozygous for 35delG mutation and 14 (7.4%) compound heterozygous for GJB2 mutations in the coding region of exon 2 whereas no significant sequence variation was found in exon 1. In 22 (11.7%) additional patients a single recessive mutation in GJB2, GJB3, GJB6 and SLC26A4 without a second mutation on the other allele was identified, making genetic counseling difficult. Our study showed significant difference in hearing loss degree in the patients with GJB2-mutations. Forty-five (45.5%) GJB2-cases were identified in 99 individuals diagnosed with severe to profound hearing loss, 14 (17.7%) GJB2-cases were identified in 79 individuals with moderate deafness whereas no clear GJB2 mutation was found in 10 patients with mild hearing loss (p < 0.001). Revealing a high variability of hearing levels in identical genotypes (even intrafamilial), a significant genotype-phenotype correlation could not be established. Based on the identified mutations spectrum and frequencies, speaking mostly of GJB2, a step by step screening for mutations can be devised and in addition may lead to a better stratification of patients for specific therapeutical approaches.

Comparing the inferior colliculus of young and old gerbils (Meriones unguiculatus) with an emphasis on GABA.

Indicators of an age-dependent down-regulation of GABA (gamma amino butyric acid) have been well-documented in the inferior colliculus (IC) of several rat strains. In the present study, we performed a quantitative light microscopic analysis of GABA-immunostained IC sections to characterize the effect of age on the cross-sectional area of the IC, the number and density of GABAergic cells and the expression of GABA in gerbils. Compared to young gerbils, a significant shrinkage of the IC but no loss of GABAergic cells was found resulting in an increased density of GABAergic cells in old gerbils. The expression of GABA in neurons and the neuropil of the IC did not differ between young and old gerbils. The results in the gerbil differ considerably from age-dependent changes described for the rat IC, showing clear species-specific differences.

Triple test as predictive screen for unilateral weakness on caloric testing in routine practice.

OBJECTIVE: To investigate in vertigo patients in routine practice to what extent a rapid and straightforward triple bedside test (spontaneous nystagmus, head-shaking nystagmus, and the head impulse test) can predict a normal result on caloric testing. STUDY DESIGN: Prospective, single-blind, diagnostic study. SETTING: Tertiary referral center. PATIENTS: 151 patients (78 male and 73 female subjects; mean age, 52.5 +/- 16.4 yr) presenting with acute or recent symptoms of vertigo. INTERVENTION: Diagnostic evaluation. MAIN OUTCOME MEASURE: The negative predictive value (NPV) of the triple test in relation to a normal caloric test response. RESULTS: In unilateral weakness (UW) on caloric testing (UW, >=25%), the triple test had sensitivity of 63.6%, specificity of 85.4%, a positive predictive value (PPV) of 71.4%, and an NPV of 80.4%. In other words, 80.4% of patients with a negative triple test also had a normal response on caloric testing. In pronounced canal paresis (UW, >=50%), the triple test had sensitivity of 81.8%, specificity of 81.4%, a PPV of 55.1%, and an NPV of 94.1%. Significant differences were found between 2 subgroups assessed by examiners with differing levels of experience (p < 0.05). CONCLUSION: The triple test represents a good screening tool that quickly and reliably excludes unilateral weakness and in particular pronounced canal paresis on caloric testing.

Nasal tip recontouring in primary rhinoplasty: the endonasal complete release approach.

OBJECTIVE: Surgery of the nasal tip is a particular challenging aspect of rhinoplasty. We describe a surgical concept in nasal tip surgery that is novel in certain aspects. It combines maneuvers that are typically reserved for the open approach with the minimally invasive concept of endonasal rhinoplasty. METHODS: Integral to the concept are the complete dissection and delivery of the lateral crus, repositioning of the dome, placement of alar strut grafts that extend far medially, and lateral advancement of the lateral crus. RESULTS: This concept of nasal tip recontouring through the endonasal complete release approach is illustrated in detail. Representative cases are displayed, and outcomes in a population of 100 consecutive young female primary rhinoplasty patients are presented. CONCLUSIONS: The concept allows for excellent cosmetic and functional outcomes through a minimally invasive approach with preservation of a naturally soft nasal tip. Patient comfort is maximized by reduced swelling, avoidance of nasal packing, and obviation of external incisions.

Occurence of a round window membrane rupture in patients with sudden sensorineural hearing loss.

BACKGROUND: Aim of the present study was to evaluate the occurence of a round window membrane rupture and the effects of hearing restoration after exploratory tympanotomy and sealing of the round window (niche) in patients with unilateral sudden deafness. METHODS: Retrospective analysis of patients' charts in a tertiary referral center. Charts of 69 patients with sudden deafness followed by exploratory tympanotomy were retrospectively analyzed. Pure-tone audiometry data before and after tympanotomy were compared to determine the outcome of hearing recovery. The postoperative hearing test values were documented 3 weeks after tympanotomy. All surgical reports were reviewed with regard to the surgical technique performed and the intraoperative findings. RESULTS: 18.8% of the patients revealed a visible perilymphatic fistula in the round window niche. 89.8% of the patients reported no typical history for a round window membrane rupture. All patients were treated with an exploratory tympanotomy under local anesthesia and an intravenous corticosteroid treatment regimen. The majority of the surgeons used a fat plomb to cover the round window. Postoperative hearing was significantly improved compared to the preoperative hearing test data. No patient showed a worsened hearing curve after the treatment. CONCLUSION: Most patients suffering from unilateral sudden deafness had no visible perilymphatic fistula. In our study population, the majority of patients reported no typical history of a pressure elevation in the inner ear. Exploratory tympanotomy is a safe procedure that may support hearing recovery in patients with sudden deafness in addition to the established treatment regimen including high-dose steroids.

Wound healing after radiation therapy: review of the literature.

Radiation therapy is an established modality in the treatment of head and neck cancer patients. Compromised wound healing in irradiated tissues is a common and challenging clinical problem. The pathophysiology and underlying cellular mechanisms including the complex interaction of cytokines and growth factors are still not understood completely. In this review, the current state of research regarding the pathomechanisms of compromised wound healing in irradiated tissues is presented. Current and possible future treatment strategies are critically reviewed.

Temporomandibular joint disorder complaints in tinnitus: further hints for a putative tinnitus subtype.

OBJECTIVE: Tinnitus is considered to be highly heterogeneous with respect to its etiology, its comorbidities and the response to specific interventions. Subtyping is recommended, but it remains to be determined which criteria are useful, since it has not yet been clearly demonstrated whether and to which extent etiologic factors, comorbid states and interventional response are related to each other and are thus applicable for subtyping tinnitus. Analyzing the Tinnitus Research Initiative Database we differentiated patients according to presence or absence of comorbid temporomandibular joint (TMJ) disorder complaints and compared the two groups with respect to etiologic factors. METHODS: 1204 Tinnitus patients from the Tinnitus Research Initiative (TRI) Database with and without subjective TMJ complaints were compared with respect to demographic, tinnitus and audiological characteristics, questionnaires, and numeric ratings. Data were analysed according to a predefined statistical analysis plan. RESULTS: Tinnitus patients with TMJ complaints (22% of the whole group) were significantly younger, had a lower age at tinnitus onset, and were more frequently female. They could modulate or mask their tinnitus more frequently by somatic maneuvers and by music or sound stimulation. Groups did not significantly differ for tinnitus duration, type of onset (gradual/abrupt), onset related events (whiplash etc.), character (pulsatile or not), hyperacusis, hearing impairment, tinnitus distress, depression, quality of life and subjective ratings (loudness etc.). CONCLUSION: Replicating previous work in tinnitus patients with TMJ complaints, classical risk factors for tinnitus like older age and male gender are less relevant in tinnitus patients with TMJ complaints. By demonstrating group differences for modulation of tinnitus by movements and sounds our data further support the notion that tinnitus with TMJ complaints represents a subgroup of tinnitus with clinical features that are highly relevant for specific therapeutic management.

Uncommon lesions in the internal auditory canal (IAC): review of the literature and case report.

BACKGROUND: Despite the relatively frequent occurrence of multiple primary tumors, namely, 10% of intracranial tumors, metastasis is a rare occurrence within the internal auditory canal (IAC) and cerebellopontine angle (CPA). Intracanalicular metastases of adenocarcinoma are documented, but a primary adenocarcinoma remains unreported. We provide a review of uncommon lesions in the IAC and describe to our knowledge the first instance of a primary adenocarcinoma. CASE REPORT: A 60-year-old man presented with nausea and vomiting. Cranial computed tomography scan revealed bilateral nonspecific periventricular and subcortical vascular lesions. He presented 8 months later with left-sided tinnitus, progressive hearing loss, and attacks of vertigo. Magnetic resonance imaging (MRI) showed an extra-axial mass most likely representing a left-sided vestibular schwannoma with characteristic contrast enhancement in the IAC. The follow-up MRI showed an unchanged pattern of contrast enhancement. Due to progressive headaches and dizziness, the patient underwent a left transtemporal craniotomy with subtotal tumor resection. Histological examination revealed blennogenic cylindrical adenocarcinoma. The investigations for the primary tumor site were all negative. The patient's condition deteriorated gradually. MRI showed an increase of the residual tumor and meningeosis carcinomatosa, and cerebrospinal fluid (CSF) examination was positive for tumor cells. The patient was treated with intrathecal chemotherapy. He died of multiple organ failure. DISCUSSION: The discussion focuses on the incidence of extra-axial CPA and IAC lesions with their clinical presentations and their radiological findings. We address the issue of a possible regulation of CPA lesion laterality by asymmetrically expressed genes. In view of the sparse literature on treatment of single intracanalicular metastases, the review is broadened to the current treatment recommendations of single brain metastases. CONCLUSIONS: The differentiation between benign and malign lesions in the CPA and IAC is important, as it requires diverse treatment protocols. For the physician this differentiation represents a clinical and radiological challenge. For the developmental research the left-right asymmetry might be a field of research.

The effect of gabapentin on gap detection and forward masking in young and old gerbils.

OBJECTIVES: Auditory temporal processing frequently appears more affected in old subjects than would be predicted by the degree of peripheral hearing loss, pointing to an age-dependent central processing deficit. In parallel, an age-dependent decline of inhibitory function has been demonstrated in the auditory pathway, suggesting a causal relationship between temporal processing and inhibition. Gabapentin has been specifically synthesized as a potential gamma-amino-butyric-acid (GABA) mimetic with the capability to cross the blood-brain barrier. Gabapentin treatment ameliorated tinnitus in a rat model and improved tinnitus annoyance in humans with acoustic trauma. Consequently, the present study evaluated the effect of gabapentin on auditory temporal processing in the gerbil model. DESIGN: Psychometric functions were collected for different test paradigms. (A) "Gap detection": The detection of a gap in the middle of a 800 msec broadband noise pulse was determined either at 15 or at 30 dB SL. (B) "Forward masking": The detection of a 20 msec probe stimulus following 2.5 msec after a 400 msec 40 dB SPL masker was determined with masker and probe frequency at 2.85 kHz. The effect of gabapentin was evaluated by collecting gap detection and forward masking functions before, during, and after treating gerbils with gabapentin doses of 115 or 350 mg/kg/day administered via drinking water. Data under different experimental conditions were collected for groups of 3 to 5 young (<2 years) and 6 to 10 old (>2 years) gerbils. Two-way analyses of variance for the factors age groups and treatment groups with subsequent pairwise comparisons for significant effects were used for the statistical evaluation of the data. RESULTS: For gap detection, mean thresholds were significantly increased in the group of old as compared with the young gerbils at 30 dB SL (young 2.0 msec; old 3.2 msec) and at 15 dB SL (young 2.9 msec; old 9.1 msec). Gabapentin had no significant effect on gap detection, and there was no significant interaction between age group and gabapentin treatment. Mean thresholds in the forward masking paradigm were significantly elevated in old (45.5 dB SPL) as compared with young (35.0 dB SPL) gerbils. Overall, gabapentin had no significant effect on masked thresholds; however, there was a significant interaction between treatment and age. Subsequent pairwise comparisons revealed no significant effect on masked thresholds in old gerbils but showed significantly elevated thresholds of young gerbils during 350 mg/kg gabapentin (38.3 dB SPL) compared with thresholds obtained in young gerbils before (32.3 dB SPL) and after (33.5 dB SPL) treatment. CONCLUSIONS: Gabapentin did not exert a therapeutic effect on impaired gap detection and forward masking in old gerbils. The lack of an effect of gabapentin on impaired auditory temporal processing in old gerbils and the finding of elevated masked thresholds in young gerbils can be reconciled with reports of only moderate GABAergic effects compared with other drugs (e.g., comparing elevation of GABA levels in the brain by gabapentin and vigabatrin) and effects due to binding of gabapentin to alpha-2-delta units of voltage-gated calcium channels.

Localization of gentamicin uptake in the acutely isolated inner ear of the rat.

The quantitative analysis of fluorescence in frozen sections of rat inner ears exposed to Texas Red conjugated gentamicin revealed distinct gradients of gentamicin fluorescence. At 500 µg/ml gentamicin fluorescence occurred in inner and outer hair cells, the interdental cell region, the spiral limbus below the interdental cells, the nerve fiber bundle in the spiral lamina, the inner sulcus cells and the dorsal region of the spiral ligament. No gentamicin fluorescence was observed in the Hensen / Claudius cells, the ventral region of the spiral ligament, the stria vascularis and the spiral ganglion. In the vestibule only the hair cell epithelium and the transitional cells of the saccule showed gentamicin fluorescence while no gentamicin fluorescence was found in hair cell epithelia and transitional cells of utricle and ampule, nerve fibers below hair cell epithelia of saccule, utricle and ampule and in dark cells. The gentamicin flurescence increased at higher concentrations. Gentamicin exposure led to more pronounced gentamicin fluorescence in the cochlea compared to the vestibule. Based on the predominant gentamicin fluorescence in the hair cell - limbus region of the cochlea at a low dose we propose that gentamicin may interact with the K(+)-flow from the inner hair cells back to the scala media.

Tinnitus with temporomandibular joint disorders: a specific entity of tinnitus patients?

OBJECTIVE: Tinnitus is frequently associated with temporomandibular joint (TMJ) dysfunction. However, the nature of the relationship is not fully understood. Here the authors compared 30 patients with a confirmed diagnosis of temporomandibular joint dysfunction and tinnitus to a group of 61 patients with tinnitus but without any subjective complaints of TMJ dysfunction with respect to clinical and demographic characteristics. STUDY DESIGN: Case-control study. SETTING: Tertiary referral center. SUBJECTS: Tinnitus patients with and without TMJ dysfunction presenting at the Department of Prosthetic Dentistry and th: Tinnitus Clinic at the University of Regensburg. RESULTS: Tinnitus patients with TMJ disorder had better hearing function (P < .0005), lower age (P = .001), and lower age at tinnitus onset (P = .002) and were more frequently female (P = .003). Their subjectively perceived tinnitus loudness was lower (P = .01), and more of them could modulate their tinnitus by jaw or neck movements (P = .001). CONCLUSION: Classical risk factors for tinnitus (age, male gender, hearing loss) are less relevant in tinnitus patients with TMJ disorder, suggesting a causal role of TMJ pathology in the generation and maintenance of tinnitus. Based on this finding, treatment of TMJ disorder may represent a causally oriented treatment strategy for tinnitus.

The role of soluble adhesion molecules and cytokines in sudden sensorineural hearing loss.

OBJECTIVE: The underlying pathology of sudden sensorineural hearing loss (SSNHL) is still not completely understood. Inflammatory and vascular factors are part of the present discussion. The aim of this study was to learn more about the possible role of adhesion molecules and cytokines in patients with SSNHL. These molecules are thought to contribute to endothelial dysfunction. STUDY DESIGN: Case-control study with planned data collection. SETTING: Tertiary referral center. SUBJECTS AND METHODS: Blood samples of 35 patients presenting with SSNHL of more than 30 dB in at least 3 contiguous frequencies were compared to a gender- and age-matched control group of normal-hearing subjects. Levels of the soluble adhesion molecules intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), endothelial selectin (E-selectin), and concentration of interleukin 6 (IL-6), interleukin 8 (IL-8), and monocyte chemoattractant protein 1 (MCP-1) were measured using established enzyme-linked immunosorbent assays. These parameters as well as fibrinogen and lipid values were statistically analyzed. RESULTS: Levels of soluble ICAM-1, VCAM-1, E-selectin, IL-6, IL-8, and MCP-1 were not significantly elevated in patients with SSNHL. The clinical chemistry and hematologic determinations showed no significant differences between patients and control subjects. CONCLUSION: This study revealed no association concerning SSNHL and typical vascular risk factors such as lipids and fibrinogen. Soluble adhesion molecules were not elevated in the SSNHL group. The role of endothelial dysfunction represented by increased levels of soluble adhesion molecules in the pathogenesis of SSNHL remains unclear. Further studies are necessary to elucidate the vascular etiology of SSNHL.

A micro-computed tomographic study: determination of the angle between the tympanic membrane and stapes footplate in a total ossicular reconstruction prosthesis reconstruction.

OBJECTIVES: To examine the anatomical relationship of the angles between tympanic membrane and stapes footplate and the variation of these angles among different temporal bones in order to characterize the optimal shape of total ossicular reconstruction prostheses (TORPs). METHODS: Ten specimens of human temporal bones were prepared for examination with micro-computed tomography. Five of the 10 temporal bones were implanted with 3 types of TORPs before subjecting them to micro-computed tomography. The angles between tympanic membrane and stapes footplate were determined. The contact of the TORPs to these structures was assessed. RESULTS: The angle between the stapes footplate and the tympanic membrane was, on average, 25.9 degrees in a plane along the transverse axis of the stapes footplate and 24.6 degrees in a plane along the longitudinal axis of the stapes footplate. Consideration of these angles in TORPs resulted in an optimal contact with the tympanic membrane and stapes footplate, especially for prostheses with a large foot. CONCLUSION: TORPs should be adjusted in shape before insertion into the middle ear. Further developments should consider prostheses with preadjusted angles or appliances for the exact modification of the prostheses during surgery.

Influence of Surface Processing on the Biocompatibility of Titanium.

Surface conditioning of titanium middle ear implants results in an improved biocompatibility, which can be characterized by the properties of fibroblasts cultured on conditioned surfaces. Titanium has been established as a favorable biomaterial in ossicular chain reconstruction. The epithelization of the surface of the implants is important for their integration and stable positioning in the middle ear. Mouse fibroblast cells were cultured on platelets made from pure Grade 2 titanium. Platelets that had been etched along their production process were compared to unetched platelets. The DNA in the cell nuclei was stained with DAPI and the actin filaments of the cytoskeleton were stained with FITC-conjugated phalloidin in order to analyze the cells grown on etched and unetched platelets by fluorescence microscopy. SEM (scanning electron microscopic) images were used to compare the surface structure of etched and unetched titanium platelets. There was a statistically significant increase of the area covered by the cytoplasm and increased actin expression by fibroblasts grown on the etched titanium platelets. In addition, the area of the platelets covered by nuclei on the etched platelets exceeded on average the one on unetched platelets, although this difference was not significant. The SEM pictures comparing unetched and etched titanium platelets showed a clear difference in surface structure. Surface conditioning of titanium implants improved the epithelization by fibroblasts and consequently etched titanium should be the preferred biomaterial for reconstructive middle ear surgery.

Prognostic importance of "clear versus revised margins" in oral and pharyngeal cancer.

BACKGROUND: Opinions differ regarding the usefulness of accurate, but costly, frozen sections. Most physicians believe that negative margins are essential for the prognosis of patients with oral and pharyngeal cancer. We examined whether immediate repeated resections in patients with positive margins, based on findings from frozen sections, resulted in improved patient survival. METHODS: Data from 417 patients identified with cancer of the pharynx and floor of the mouth were analyzed retrospectively. RESULTS: The 5-year survival rate for R0 and R1-R0 groups was 72% to 76% and was significantly better (p ≤ .034) than that for R1 and R2 groups (58%, 40%). Despite clear margins, large tumors had a poorer prognosis than that of small tumors. CONCLUSIONS: Patients receiving repeated resection had the same survival rate as patients who had the tumor resected immediately with negative margins. The use of frozen sections yields a benefit for 15.6% of the operated patients and increases the overall 5-year survival rate by 2% to 3%.