http://repub.eur.nl/res/aut/5406/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/20658/ 2010-07-01T00:00:00Z Laryngotracheal reconstruction requires a supportive structure with a mucosal lining, which needs a vascular supply in order to regenerate properly. We investigated the necessity of a vascular carrier and mucosal graft when using porous titanium for laryngotracheal reconstruction. Surgical defects of the laryngotracheal complex in 22 rabbits were reconstructed with: (a) porous titanium implanted on a vascularized fascia combined with a buccal mucosal graft (first stage) before transposing to the neck area (second stage); (b) porous titanium implanted on a vascularized fascia (first stage) combined with a mucosal graft (second stage); (c) porous titanium on a pedicled fascia flap; and (d) porous titanium alone. The grafts were tolerated well. Re-epithelialization occurred in all groups. Normal mucosa with a submucosal layer containing vital cells was noted using the titanium implants. Blood vessels were grown in the pores of the titanium scaffold to supply the overlying mucosa. The scaffold was well integrated in the adjacent tracheal cartilage and surrounding tissues, except in the two cases that showed titanium displacement. Inflammation and granulation formation were seen in most rabbits in groups III and IV, initiated probably by the use of buccal mucosal grafts. Reconstruction of a rabbit's trachea using composites of porous titanium, mucosal grafts and a fascia flap is feasible. Titanium seems to meet the requirements needed for closing a small defect of the tracheal wall and allows for re-epithelialization. For larger defects, a vascular carrier with a mucosal graft is probably indispensable to ensure the process of re-epithelialization. http://repub.eur.nl/res/pub/25177/ 2009-10-01T00:00:00Z Objective: To evaluate the results of one-stage surgical repair of the meatal skin defect in patients with long-lasting osteoradionecrosis of the outer ear canal, using a postauricular, inferiorly pedicled skin flap. All patients were also treated with hyperbaric oxygen both pre- and post-operatively.Methods: A prospective study evaluating the results of a one-stage surgical procedure to repair the meatal skin defect in five patients with osteoradionecrosis of the outer ear canal. All patients were treated with hyperbaric oxygen both pre- and post-operatively.Results: In four of the five patients, intact canal skin was achieved after surgery and hyperbaric oxygen therapy. One patient needed a second operation to cover a small remaining area of bare bone. In one patient, wound healing was unsatisfactory and an area of bare bone remained.Conclusion: In cases of osteoradionecrosis of the outer ear canal, the skin defect can be repaired with an inferiorly pedicled skin flap. Although not yet scientifically proven, the peri-operative application of hyperbaric oxygen may be of additional value to improve wound healing in areas of compromised tissue. http://repub.eur.nl/res/pub/24180/ 2009-06-01T00:00:00Z Self-reported outcome on hearing disability and handicap as well as overall health-related quality of life were measured after hearing-aid fitting in a large-scale clinical population. Fitting was performed according to two different procedures in a double-blind study design. We used a comparative procedure based on optimizing speech intelligibility scores and a strictly implemented fitting formula. Hearing disability and handicap were assessed with the hearing handicap and disability inventory and benefit of hearing aids with the abbreviated profile of hearing aid benefit. Effects on health-related quality of life and depression were assessed with the EuroQol-5D questionnaire and the geriatric depression scale. We found that hearing-aid fitting according to either procedure had a significantly positive effect on disability and handicap associated with hearing loss. This effect lasted for several months. Only the effect on disability persisted after 1-year of follow-up. Self-reported benefit from hearing aids was comparable for both fitting procedures. Unaided hearing disability was more pronounced in groups of participants with greater hearing loss, while the benefit of hearing aids was independent from the degree of hearing impairment. First-time hearing aid users reported greater benefit from their hearing aids. The added value from a bilateral hearing-aid fitting was not significant. Overall health-related quality of life and incidence of depression did not alter after hearing-aid fitting. http://repub.eur.nl/res/pub/17612/ 2009-05-01T00:00:00Z OBJECTIVE: To investigate whether porous titanium can provide a better support for revascularization of a mucosal graft ideal for tracheal reconstruction. In patients with laryngotracheal stenosis or tumor, the mucosa with supporting structures can be damaged, resulting in a defect that has to be reconstructed. Autologous tissues like cartilage and mucosa have been used for reconstruction. The main problem has been incomplete mucosal reepithelialization. DESIGN: In the first experiment, porous titanium or ear cartilage was combined with mucosa and implanted subcutaneously in athymic mice for different periods of time. In the second experiment, using rabbits, surgically created defects were reconstructed with porous titanium and mucosa on a pedicled fascia flap using a 2-stage procedure. The implants were analyzed with emphasis on angiogenesis and mucosal survival. SUBJECTS: Male New Zealand white rabbits and nude athymic mice (BALB-c nu/nu). RESULTS: Normal mucosa having a submucosal layer with vital cells was noted on top of the titanium. Multiple blood vessels were observed extending from the muscle layer through the titanium. Cytokeratin expression was detected in the suprabasal and basal layers of the mucosal epithelium. In contrast, the mucosa on cartilage showed no vital cells and no cytokeratin expression. In the rabbit experiment, all animals survived the reconstruction. The titanium was well integrated to the adjacent tracheal cartilage and surrounding tissues, supporting a fully vital mucosa. CONCLUSIONS: Porous titanium is an inert biomaterial that provides support and allows easy revascularization of a mucosal graft. Titanium, in combination with viable autologous tissues, is a good alternative for tracheal reconstruction. http://repub.eur.nl/res/pub/16267/ 2009-02-01T00:00:00Z OBJECTIVES/HYPOTHESIS: Several studies have shown the presence of pepsin in the middle ear effusions of children with otitis media with effusion (OME). When gastric reflux is the cause, other noxious reflux products might be present. We therefore investigated the presence of bile acids in the middle ear effusions of children with OME. STUDY DESIGN: We evaluated 38 children (63 samples of middle ear secretions (ME samples)) in a prospective study at a tertiary care children's hospital. METHODS: ME samples were collected from children with OME during ventilation tube insertion. Most ME samples were diluted with albumin. The presence of bile acids was measured with the 3alpha-hydroxy steroid dehydrogenase enzymatic method. A ME sample was considered positive when it contained at least 5 mumol/l bile acids, independent of dilution. Blood samples were taken simultaneously as a reference to determine bile acids serum levels. RESULTS: We found bile acids in 32 % (20/63) of all ME samples and in 42% (16/38) of all children. Bile acids concentrations of 12 well-soluble ME samples ranged from 5.9-40.9 mumol/L and were 3.1-19.7 times higher than the serum concentrations. In 4 of the corresponding serums, no bile acids were measurable at all. CONCLUSIONS: Bile acids are present in a number of the ME samples of children with OME. Because of dilution, it is possible that more ears contain bile acids. Bile acids are known to be noxious to mucosal cells at a higher (pH) than pepsin and, therefore, might play a role in the pathology of OME. http://repub.eur.nl/res/pub/14332/ 2008-12-01T00:00:00Z Objectives: Traumatic perforations of the eardrum are generally treated conservatively as they tend to heal spontaneously. Retraction pockets of the eardrum, leading to atelectasis of the middle ear and often ultimately though unpredictably, to cholesteatoma formation, are treated in a variety of ways including complex grafting procedures. On the premise that a surgically resected retraction pocket is in essence a traumatic perforation, we examined the results of spontaneous healing of the resected retraction pocket. Methods: Retrospective case note study. Patients: A group of 86 ears in 62 patients who had undergone simple excision of the atrophic segment of the eardrum and who had no grafting procedure of the resultant defect, were followed at 6 days, 6-7 weeks and then every 6 months to determine the incidence of spontaneous healing of the eardrum. Audiograms were taken preoperatively, at 7 weeks and between 7 and 15 months postoperative. Results: 94.2% of the eardrums (81 out of 86 ears) healed spontaneously without any form of grafting within 7 weeks. Air bone gap showed improvement in 53 patients. Only one of the four ears that failed to achieve closure had postoperative ear discharge. There were no other complications. In 17 ears (19.8%) there was a recurrence of the atelectasis. Conclusion: Excision of retraction pockets in pediatric ear atelectasis, in principle does not require grafting, as the great majority will heal spontaneously. The spontaneous healing in this study is comparable to reported studies of spontaneous healing of traumatic perforations. Irrespective of the size of the atrophic part of the membrane, recurrence rates for the atelectasis after simple excision is similar to that described in other studies. Retraction pockets may be excised and allowed to heal without risk to the hearing. http://repub.eur.nl/res/pub/29889/ 2008-09-01T00:00:00Z We compared two different types of hearing-aid fitting procedures in a double-blind randomized clinical study. Hearing aid fittings based on a purely prescriptive procedure (the NAL-RP formula) were compared to a comparative fitting procedure based on optimizing speech intelligibility scores. Main outcome measures were improvement of speech intelligibility scores in quiet and in noise. Data were related to the real-ear insertion responses that were measured after fitting. For analysis purposes subgroups were composed according to degree of hearing loss, characterized by unaided speech intelligibility in quiet, previous experience with hearing aids, unilateral or bilateral fittings and type of hearing aid. We found equal improvement of speech intelligibility in quiet, while fitting according to the prescriptive formula resulted in a somewhat better performance as expressed by the speech-to-noise ratio in comparison to the comparative procedure. Both procedures resulted in comparable real-ear insertion responses. http://repub.eur.nl/res/pub/29824/ 2008-03-01T00:00:00Z Summary: The purpose of this study was to investigate the usefulness of the Dysphonia Severity Index (DSI) as an objective multiparametric measurement in assessing dysphonia. The DSI was compared with the score on Grade of the GRBAS scale. Investigated was also whether the DSI is related to severity of dysphonia, which was represented by different diagnosis groups. Furthermore, it was investigated whether the DSI can differentiate between a group of patients and a control group. A total of 294 patients with different voice pathologies were included. A control group consisted of 118 volunteers without any voice complaints. The voices of all participants were perceptually evaluated on Grade, and the DSI was measured. The groups of patients with voice complaints have a lower DSI and higher scores on Grade than the control group. The DSI was significantly lower when the score on Grade was higher. The DSI discriminates between patients with nonorganic voice disorders, vocal fold mass lesions, and vocal fold paresis/paralysis. To determine whether the DSI discriminates between patients and controls, the sensitivity and specificity for different DSI cutoff points were calculated. With a DSI cutoff of 3.0, maximum sensitivity (0.72) and specificity (0.75) were found. We conclude that the DSI is a useful instrument to objectively measure the severity of dysphonia. http://repub.eur.nl/res/pub/30055/ 2008-02-01T00:00:00Z Objective: The purpose of this study was to investigate the interobserver variability and the test-retest variability of the Dysphonia Severity Index (DSI), a multiparametric instrument to assess voice quality. Methods: The DSI was measured in 30 nonsmoking volunteers without voice complaints or voice disorders by two speech pathologists. The subjects were measured on 3 different days, with an interval of 1 week. Results: The difference in DSI between two observers (interobserver difference) was not significant. The intraclass correlation coefficient for the DSI was 0.79. The standard deviation of the difference between two duplicate measurements by different observers was 1.27. Conclusion: Differences in measurements between different observers were not significant. The intraclass correlation coefficient of the DSI was 0.79, which is to be considered good. Differences in DSI within one patient need to be larger than 2.49 to be significant. Copyright http://repub.eur.nl/res/pub/14144/ 2008-01-01T00:00:00Z Objective: There is no consensus amongst clinicians regarding the best treatment strategy for pediatric atelectasis of the middle ear. It is the policy in our pediatric otolaryngology department to intervene early in the disease process. In an attempt to provide evidence regarding the safety of early intervention we have analyzed the audiological outcome following surgery in different stages of the disease. Study design: Retrospective case note review. Methods: We undertook a retrospective study of children with atelectasis treated surgically at a Dutch tertiary referral centre. Disease severity was classified according to the Erasmus Classification of Pediatric Atelectasis, and pre- and postoperative four frequency ac and bc thresholds were compared. Results: The study group consisted of 169 ears in 127 patients. The mean age at surgery was 9.6 years. There was an improvement in the average air-bone gap (ABG) for all stages. No deterioration in mean bone conduction thresholds was found following surgical intervention and there were no dead ears postoperatively. Conclusion: This study demonstrated that surgical intervention had a favourable effect on hearing level across all stages, though hearing was markedly worse in stage V, and that a policy of intervention early in the disease process cannot be rejected on the grounds of risk of iatrogenic sensorineural hearing loss. http://repub.eur.nl/res/pub/30256/ 2008-01-01T00:00:00Z Halitosis is an unpleasant or offensive odour, emanating from the oral cavity. In approximately 80% of all cases, halitosis is caused by microbial degradation of oral organic substrates. Major degradation products are volatile sulphur-containing compounds. In this review, the available management methods of halitosis and their effectiveness and significance are presented and discussed. Undoubtedly, the basic management is mechanically reducing the amount of micro-organisms and substrates in the oral cavity. Masking products are not, and antimicrobial ingredients in oral healthcare products are only temporary effective in reducing micro-organisms or their substrates. Good short-term results were reported with chlorhexidine. Triclosan seems less effective, essential oils and cetylpyridinium chloride are only effective up to 2 or 3 h. Metal ions and oxidizing agents, such as hydrogen peroxide, chlorine dioxide and iminium are active in neutralizing volatile sulphur-containing compounds. Zinc seems to be an effective safe metal at concentrations of at least 1%. The effectiveness of active ingredients in oral healthcare products is dependent on their concentration and above a certain concentration the ingredients can have unpleasant side effects. Tonsillectomy might be indicated if (i) all other causes of halitosis are managed properly; (ii) halitosis still persists and (iii) crypts in tonsils are found to contain malodorous substrates. http://repub.eur.nl/res/pub/29915/ 2008-01-01T00:00:00Z Although a large number of fitting procedures have been developed and are nowadays generally applied in modern hearing aid fitting technology, little is known about their effectiveness in comparison with each other. This paper argues the need for comparative validation studies on hearing aid fitting procedures based on the design of a randomized clinical trial and carried out in a large-scale clinical population. These studies are hard to conduct but can provide detailed information on the various aspects of the rehabilitation with hearing aids. The design of several recently reported comparative studies of hearing aid fitting procedures will be reviewed. This gives rise to a number of comments on aspects like, study design, composition of the study population and definition of outcome measures rather than on the outcome or conclusions of these studies themselves. http://repub.eur.nl/res/pub/36045/ 2007-08-01T00:00:00Z Objectives: This work reviews the current knowledge of aetiology and measurement methods of halitosis. Data: Halitosis is an unpleasant or offensive odour emanating from the breath. The condition is multifactorial and may involve both oral and non-oral conditions. Sources: A private, monthly with keywords halitosis, malodo(u)r, (a)etiology, measurement, and management from Medline and Pubmed updated database of literature was reviewed. Conclusions: In approximately 80-90% of all cases, halitosis is caused by oral conditions, defined as oral malodour. Oral malodour results from tongue coating, periodontal disease, peri-implant disease, deep carious lesions, exposed necrotic tooth pulps, pericoronitis, mucosal ulcerations, healing (mucosal) wounds, impacted food or debris, imperfect dental restorations, unclean dentures, and factors causing decreased salivary flow rate. The basic process is microbial degradation of organic substrates. Non-oral aetiologies of halitosis include disturbances of the upper and lower respiratory tract, disorders of the gastrointestinal tract, some systemic diseases, metabolic disorders, medications, and carcinomas. Stressful situations are predisposing factors. There are three primary measurement methods of halitosis. Organoleptic measurement and gas chromatography are very reliable, but not very easily clinically implemented methods. The use of organoleptic measurement is suggested as the 'gold standard'. Gas chromatography is the preferable method if precise measurements of specific gases are required. Sulphide monitoring is an easily used method, but has the limitation that important odours are not detected. The scientific and practical value of additional or alternative measurement methods, such as BANA test, chemical sensors, salivary incubation test, quantifying β-galactosidase activity, ammonia monitoring, ninhydrin method, and polymerase chain reaction, has to be established. http://repub.eur.nl/res/pub/35329/ 2007-07-01T00:00:00Z The inferior colliculus (IC) is a large auditory nucleus in the midbrain, which is a nearly obligatory relay center for ascending auditory projections. We made in vivo whole cell patch-clamp recordings of IC cells in young-adult anesthetized C57/Bl6 mice and Wistar rats to characterize their membrane properties and spontaneous inputs. We observed spikelets in both rat (18%) and mouse (13%) IC neurons, suggesting that IC neurons may be connected by electrical synapses. In many cells, spontaneous postsynaptic potentials were sufficiently large to contribute to spike irregularity. Cells differed considerably in the number of simultaneous spontaneous postsynaptic potentials that would be needed to trigger an action potential. Depolarizing and hyperpolarizing current injections showed six different types of firing patterns: buildup, accelerating, burst-onset, burst-sustained, sustained, and accommodating. Their relative frequencies were similar in both species. In mice, about half of the cells showed a clear depolarizing sag, suggesting that they have the hyperpolarization-activated current Ih. This sag was observed more often in burst and in accommodating cells than in buildup, accelerating, or sustained neurons. Cells with Ihhad a significantly more depolarized resting membrane potential. They were more likely to fire rebound spikes and generally showed long-lasting afterhyperpolarizations following long depolarizations. We therefore suggest a separate functional role for Ih. Copyright http://repub.eur.nl/res/pub/35594/ 2007-02-01T00:00:00Z Background: Nasal nitric oxide (nNO) values are reduced in patients with cystic fibrosis (CF). Humming during nNO measurement increases nNO values in healthy subjects. Nasal NO is reduced in patients with CF, sinus disease or nasal polyps. Humming nNO values have not been reported in CF patients yet. Our aim was to explore humming nNO values in CF patients and assess whether nNO during humming is a better discriminator than silent nNO measurements in this patient group. Materials and methods: In a cross sectional study we measured nNO concentrations in healthy controls (HC) and in CF patients (n = 23 and 31, respectively). The participants held their breath for 10 s while air was passively extracted from one nostril with 700 mL min-1for direct NO measurements (NIOX chemiluminescence analyser). Subsequently nNO was measured during humming with the mouth closed for 10 s. Results: Mean nNO in parts per billion (p.p.b.) (SD) during breath hold was 499 (164) and 240 (139), respectively. The median nNO peak (p.p.b., minimum-maximum) during humming was 1500 (425-4100) for HC and 120 (23-500) for CF. There was a highly significant difference between nNO both with and without humming between CF and HC (P < 0·01). The sensitivity and specificity of nNO for detecting CF were better with humming. Conclusion: Nasal NO concentrations with and without humming are significantly decreased in CF. Humming nNO is an excellent discriminator between HC and CF and performs better than silent nNO. http://repub.eur.nl/res/pub/8525/ 2004-01-01T00:00:00Z The objective of the present study was to investigate whether treatment of articular cartilage with hyaluronidase and collagenase enhances histological and mechanical integration of a cartilage graft into a defect. Discs of 3 mm diameter were taken from 8-mm diameter bovine cartilage explants. Both discs and annulus were either treated for 24 hours with 0.1% hyaluronidase followed by 24 hours with 10 U/ml collagenase or left untreated (controls). Discs and annulus were reassembled and implanted subcutaneously in nude mice for 5 weeks. Integration of disc with surrounding cartilage was assessed histologically and tested biomechanically by performing a push-out test. After 5 weeks a significant increase in viable cell counts was seen in wound edges of the enzyme-treated group as compared with controls. Furthermore, matrix integration (expressed as a percentage of the total interface length that was connected; mean +/- standard error) was 83 +/- 15% in the treated samples versus 44 +/- 40% in the untreated controls. In the enzyme-treated group only, picro-Sirius Red staining revealed collagen crossing the interface perpendicular to the wound surface. Immunohistochemical analyses demonstrated that the interface tissue contained cartilage-specific collagen type II. Collagen type I was found only in a small region of fibrous tissue at the level of the superficial layer, and collagen type III was completely absent in both groups. A significant difference in interfacial strength was found using the push-out test: 1.32 +/- 0.15 MPa in the enzyme-treated group versus 0.84 +/- 0.14 MPa in the untreated controls. The study shows that enzyme treatment of cartilage wounds increases histological integration and improves biomechanical bonding strength. Enzymatic treatment may represent a promising addition to current techniques for articular cartilage repair. http://repub.eur.nl/res/pub/13193/ 2003-11-15T00:00:00Z The cervico-ocular reflex (COR) is an ocular stabilization reflex that is elicited by rotation of the neck. It works in conjunction with the vestibulo-ocular reflex (VOR) and the optokinetic reflex (OKR) in order to prevent visual slip over the retina due to self-motion. The gains of the VOR and OKR are known to decrease with age. We have investigated whether the COR, a reflexive eye movement elicited by rotation of the neck, shows a compensatory increase and whether a synergy exists between the COR and the other ocular stabilization reflexes. In the present study 35 healthy subjects of varying age (20-86 years) were rotated in the dark in a trunk-to-head manner (the head fixed in spaced with the body passively rotated under it) at peak velocities between 2.1 and 12.6 deg s-1 as a COR stimulus. Another 15 were subjected to COR, VOR and OKR stimuli at frequencies between 0.04 and 0.1 Hz. Three subjects participated in both tests. The position of the eyes was recorded with an infrared recording technique. We found that the COR-gain increases with increasing age and that there is a significant covariation between the gains of the VOR and COR, meaning that when VOR increases, COR decreases and vice versa. A nearly constant phase lag between the COR and the VOR of about 25 deg existed at all stimulus frequencies.