[Care and medical costs of urticaria in children in Germany : Drugs, medical and inpatient services]. / Versorgung und Krankheitskosten der Urtikaria bei Kindern in Deutschland : Arzneimittel, ärztliche und stationäre Leistungen.

BACKGROUND: Data on the course of urticaria in children exist, but there is a lack of sound data on patient management to ensure high-quality care. METHODS: Retrospective secondary data analysis in the field of health care and epidemiology in children with urticaria based on routine data from a German health insurance company (DAK-Gesundheit). Data from insured persons under 18 years of age who were treated as outpatients or inpatients with a diagnosis of urticaria (according to ICD-10 classification) in 2010-2015 were included. The control group consisted of children without a corresponding diagnosis, in order to clarify health economic and care-related differences after adjusting for age and gender. RESULTS: In 2015, 1904 (1.3%) of 151,248 insured minors had a diagnosis of urticaria. Of the children with urticaria, 70.9% visited at least one physician on an outpatient basis. Of these visits, 70.9% were made to a pediatrician, 52.5% to a general practitioner and 33.0% to a dermatologist; 11% were treated as inpatients. With a total of 151,248 insured persons, 1904 of whom were diagnosed with urticaria, 72.9% of children and adolescents with versus 28.9% without urticaria were treated topically or systemically in 2015, including 10.5% of children with urticaria vs. 2.6% without urticaria received topical therapy and 70.0% with urticaria received systemic therapy vs. 27.5% without urticaria with systemic therapy. The most commonly used oral medications for urticaria were cetirizine (44.2%), prednisolone (9.8%), and dimetindene (2.0%) . Topical methylprednisolone aceponate (49.8%) was prescribed most frequently. The therapy costs for systemic drugs was €â€¯24.00 per patient, while topical drugs cost €â€¯1.58 per patient. CONCLUSION: The lack of guidelines for the standardization of treatment in children still leads to ambiguities and different treatment concepts among the specialist groups, which must be eliminated in order to enable more efficient therapies. The treatment of chronic urticaria in children and adolescents is mainly carried out by pediatricians, general practitioners and dermatologists. Systemic and topical medications as well as inpatient services are the most important cost factors.

Increased Fluorohydroxyapatite across Dentin after Fluoride Iontophoresis.

Due to the multiple factors contributing to dentin demineralization and hypersensitivity among individuals, the effectiveness of the available treatments in the long term remains unclear. A recent study reported a simple strategy to potentially mimic natural remineralization with increased crystallization on the enamel caries using fluoride iontophoresis. Such an effect is also ideal for accomplishing dentin biomineralization and structural strength. This study aimed to investigate structural and compositional characteristics and permeability changes after fluoride iontophoresis with different polarities, cathodal iontophoresis (CIP), anodal iontophoresis (AIP), and the control without iontophoresis for the treatment of etched dentin under simulated pulpal pressure. The 24 premolars were divided into 3 groups: CIP, AIP, and topical application of 5% sodium fluoride (NaF) for 40 s. Relative to before treatment, iontophoresis with both polarities significantly decreased the permeability with a visible increase in occluding tubules containing crystal formation and growth throughout the dentin structure and depth. The CIP not only restored the etched dentin surface into a sound condition but also reinforced the dentin across the structure and depth by the synergistic effects of remineralization, increasing crystal formation and transformation toward the more crystalline structure of fluorohydroxyapatite. Following topical treatment, X-ray diffraction analysis and Raman spectra revealed a significant reduction in the crystal size and crystallinity associated with the raised B-type carbonate substitution into the hydroxyapatite compared with that in the sound dentin. The result was the first to reveal the ideal strategy to rapidly restore the etched dentin surface into a sound condition, including reinforcing the dentin across the structure and depth by the synergistic effects of decreasing permeability, increasing crystal formation, and transformation toward the more crystalline structure of fluorohydroxyapatite using the 5% NaF applied with the DC cathode iontophoresis. The technique is noninvasive and simple and deserves further development for clinical application.

Ethosomes: a potential nanovesicular carrier to enhancing the drug delivery against skin barriers.

Ethosomes, which are liposomes like structures, mainly composed primarily of ethanol, have attracted considerable attention due to their potential to enhance the drug permeation via skin. The article discusses the formulation and preparation methods of ethosomes, offering insights into the various factors that influence their size, shape, and stability. Moreover, it explores the techniques used to assess the physicochemical properties of ethosomes and their impact on drug delivery effectiveness. The article also elucidates the mechanism by which ethosomes enhance skin permeation, emphasising their ability to modify the lipid structure and fluidity of the stratum corneum. Additionally, the review investigates the applications of ethosomes in diverse drug delivery scenarios, including the delivery of small molecules, peptides, and phytoconstituents. It highlights the potential of ethosomes to improve drug bioavailability, extend drug release, and achieve targeted delivery to specific skin layers or underlying tissues.

Comparing Peribulbar and Topical Anesthesia in Cataract Surgery among Patients with Cardiovascular Disease.

PURPOSE: To compare topical and peribulbar anesthesia in cataract surgery for hemodynamic changes, rate of complications and pain score in patients with cardiovascular disease. METHODS: A prospective comparative study at a tertiary care center in India. Patients >40 years old with treated/controlled hypertension and cardiovascular disease scheduled for cataract surgery under topical or peribulbar anesthesia were recruited. Heart rate, blood pressure, and ophthalmic and systemic complications were noted: preoperatively, immediately after block, intraoperatively, immediately postoperatively and 1 hour postoperatively. A visual analog scale was used to assess the pain score. RESULTS: A total of 150 patients (75 in each group) underwent cataract surgery. There was a significant rise in pulse rate and blood pressure after peribulbar injection and intraoperatively, which gradually reduced to baseline 1 hour after surgery in both groups (p < 0.001), with systolic blood pressure intraoperatively being significantly greater in the peribulbar group (155.49 ±18.14 mmHg vs. 147.95 ±17.71 mmHg, p = 0.01). The topical group had slightly lower visual analog scale scores (1.12 ± 0.99) than the peribulbar group (1.44 ± 0.90, p = 0.04). CONCLUSIONS: Cataract surgery appears safe in patients with adequately controlled cardiovascular disease, and topical anesthesia may be preferable due to noninvasiveness, adequate analgesia, and minimal effect on hemodynamic parameters. Therefore, hemodynamically stable patients of cardiovascular disease undergoing uncomplicated cataract surgery may be counselled for topical anesthesia.

Efficacy and Safety of Mitomycin Gel (UGN-101) as an Adjuvant Therapy After Complete Endoscopic Management of Upper Tract Urothelial Carcinoma.

PURPOSE: We describe a novel application of the reverse thermal polymer gel of mitomycin C (UGN-101) as adjuvant therapy after complete endoscopic ablation of upper tract urothelial carcinoma. MATERIALS AND METHODS: We retrospectively reviewed patients treated with UGN-101 from 15 high-volume centers. Adjuvant therapy was defined as treatment administered following visually complete endoscopic ablation. Response at primary endoscopic evaluation was defined as no visual tumor or negative biopsy. Ipsilateral disease-free and progression-free survival were estimated by the Kaplan-Meier method. Ureteral stenosis and other adverse events were abstracted from the medical records. Ureteral stenosis was defined as a condition requiring ureteral stent or nephrostomy, or that would typically warrant stent or nephrostomy. RESULTS: Adjuvant UGN-101 after complete endoscopic ablation was used in 52 of 115 (45%) renal units in the oncologic analysis. At first endoscopic evaluation, 36/52 (69%) were without visible disease. At 6.8 months' median follow-up, the ipsilateral disease-free rate was 63%. Recurrence after adjuvant UGN-101 therapy was more likely in multifocal tumors compared to unifocal (HR 3.3, 95% CI 1.07-9.91). Compared with UGN-101 treatment for chemoablation of measurable disease, there were significantly fewer disease detections with adjuvant therapy (P < .001). Ureteral stenosis after UGN-101 was diagnosed in 10 patients (19%) undergoing adjuvant therapy compared to 17 (29%) undergoing chemoablative therapy (P = .28). CONCLUSIONS: In patients being considered for UGN-101, maximal endoscopic ablation prior to UGN-101 treatment may result in fewer patients with disease at first endoscopy and possibly fewer adverse events than primary chemoablative therapy. Longer follow-up is needed to determine if UGN-101 after complete endoscopic ablation will lead to durable disease-free interval.

Enamel Remineralization and Crystallization after Fluoride Iontophoresis.

Early caries lesions consist of noncavitated subsurface demineralization caused by the dissolution of hydroxyapatite from the surface to the subsurface area of the enamel. Such lesions cannot be remineralized effectively by the conventional treatment. Thus, there is a need for a noninvasive technique capable of delivering the remineralizing agent to subsurface sites. For this purpose, fluoride iontophoresis (IP) using weak currents has been investigated with some conflicting results and no information on the crystal structure and composition. Because enamel remineralization involves the role of fluid from dentin, the presence of enamel fluid is necessary to determine the repair associated with the physiological condition. This study aimed to investigate structural and compositional characteristics, including the remineralizing effect of 5% sodium fluoride (NaF) IP with different polarities, cathodal iontophoresis (CIP), and anodal iontophoresis (AIP) for the treatment of natural enamel caries under simulated pulpal pressure. A bulk measurement of the crystal structure inside the lesion was first determined using calcium (Ca) K-edge X-ray absorption spectroscopy. IP with both polarities significantly promoted subsurface remineralization. The CIP generated a significant increase in the Ca/phosphorus ratio, and fluoride at the surface lesion significantly correlated with higher mineral density (MD) and more strengthening crystal structure of the lesion volume, while the lesion's MD and other impurities at the lesion surface, mostly the carbonate ions, affected the significant increase in MD with the unchanged structure of the lesion volume after AIP. The CIP of NaF is an ideal method for rapid enamel remineralization and recrystallization of fluoroapatite/fluorohydroxyapatite.

Pain management & opioid dose reduction with topical sevoflurane instillations in intractable venous ulcers: a case report

Abstract Vascular ulcers (VU) constitute a major cause of pain and disability, and significantly compromise quality of life. VU have a natural tendency to become chronic and in many cases exhibit anunsatisfactoryresponse to many of the standard therapeutic options.The case of a 73 year-old Caucasian female with severe pain and poorly-controlled pain (Visual Analogic Scale-VAS- of 8-9) due to three lower leg long-standing VUs is reported and discussed herein. The patient was treated with topical instillations of undiluted sevoflurane as per institutional off-label protocol (starting doses of 1mL/cm2 twice a day, and up-titrated according to response to a maximum of 7 mL twice daily). The VAS score dropped to 0-1 shortly after initiation of therapy and remained stable throughout treatment up until the closure of the observations. Subsequently, opioid therapy was gradually tapered down and ultimately abandoned.Sevoflurane application resulted on adequate and sustained pain management of refractory VU, with no significant side effects. On account of its beneficial effectivity and safety profiles, topical sevoflurane emerges as an add-on alternative for the long-term management of VU, and potentially other painful conditions.

Clay Nanotube Immobilization on Animal Hair for Sustained Anti-Lice Protection.

Topical administration of drugs is required for the treatment of parasitic diseases and insect infestations; therefore, fabrication of nanoscale drug carriers for effective insecticide topical delivery is needed. Here we report the enhanced immobilization of halloysite tubule nanoclay onto semiaquatic capybaras which have hydrophobic hair surfaces as compared to their close relatives, land-dwelling guinea pigs, and other agricultural livestock. The hair surface of mammals varies in hydrophobicity having a cortex surrounded by cuticles. Spontaneous 1-2 µm thick halloysite hair coverages on the semi-aquatic rodent capybara, non-aquatic rodent guinea pig, and farm goats were compared. The best coating was found for capybara due to the elevated 5 wt% wax content. As a result, we suggest hair pretreatment with diluted wax for enhanced nanoclay adsorption. The formation of a stable goat hair coverage with a 2-3 µm halloysite layer loaded with permethrin insecticide allowed for long-lasting anti-parasitic protection, enduring multiple rain wettings and washings. We expect that our technology will find applications in animal parasitosis protection and may be extended to prolonged human anti-lice treatment.

Transdermal Delivery of Lidocaine-Loaded Elastic Nano-Liposomes with Microneedle Array Pretreatment.

This study aimed to improve the transdermal delivery of lidocaine hydrochloride (LidH) using elastic nano-liposomes (ENLs) and microneedle (MN) array pretreatment. LidH-containing ENLs were prepared using soybean phosphatidylcholine and cholesterol, with Span 80 or Tween 80, using a reverse-phase evaporation method. The ENL particle size, stability, and encapsulation efficiency (EE) were characterized and optimized based on the component ratio, pH, and type of surfactant used. In vitro transdermal diffusion study was performed on MN-pretreated mouse skin using Franz diffusion cells. The anesthetic effects of LidH in various formulations after dermal application were evaluated in vivo in rats by measuring the tail withdrawal latency after photothermic stimulation. Stable LidH-loaded Tween 80 or Span 80 ENLs were obtained with particle sizes of 115.8 and 146.6 nm and EEs of 27% and 20%, respectively. The formulations did not exert any cytotoxicity in HaCaT cells. Tween 80 and Span 80 ENL formulations showed enhanced LidH delivery on pretreated mice skin in vitro and prolonged the anesthetic effect in vivo compared to that by LidH application alone. LidH-loaded ENLs applied to MN-pretreated skin can shorten the onset time and prolong the anesthetic effect safely, which merits their further optimization and practical application.

Topical application of (S)-(-)-limonene is as effective as phonophoresis for improving oxidative parameters of injured skeletal muscle in rats.

The aim of this study is to investigate the effects of limonene, alone or associated with therapeutic ultrasound, on oxidative stress following skeletal muscle injury. Thirty male Wistar rats were divided into 5 groups: CTR-control, MI-muscle injury without treatment, TPU-therapeutic pulsed ultrasound alone, TPU + LIM-phonophoresis with 5% limonene, and LIM-5% limonene applied topically. Muscle injury was induced by a mechanical abrupt impact over gastrocnemius muscle. The animals were treated in the following intervals: 2, 12, 24, 48, 72, and 96 h after injury. Blood and gastrocnemius samples were collected 98 h after lesion for data analysis. Creatine kinase (CK) and lactate dehydrogenase (LDH) activity, lipid peroxidation (TBARS) levels, catalase (CAT), and superoxide dismutase (SOD) activity were assessed. CK (p = 0.01), SOD activity (p < 0.01), and TBARS levels (p < 0.01) were increased after injury. There was no effect on LDH levels in any group. Phonophoresis (TABRS p < 0.01; SOD p = 0.01), TPU alone (TBARS p < 0.01; SOD p = 0.01), and LIM alone (TBARS p < 0.01; SOD p < 0.01) reduced TBARS levels and SOD activity after muscle injury. There was no change for CAT activity after injury. Only phonophoresis reduced CK activity after injury (p < 0.01). There was no difference between phonophoresis, TPU alone and LIM alone groups for TBARS, SOD, CAT, and LDH. Limonene alone and TPU alone were effective in reducing oxidative stress parameters after skeletal muscle injury. Only phonophoresis decreased CK activity. Skeletal muscle injury increases reactive oxidative species (ROS) levels and muscle proteins activity as creatine kinase (CK) and lactate dehydrogenase (LDH). Five percent limonene, alone or associated with therapeutic pulsed ultrasound, exhibited reduction of CK, superoxide dismutase (SOD) and catalase (CAT) activity, and lipid peroxidation markers (TBARS). Graphical abstract.

[New developments in topical pharmaceuticals]. / Neue Entwicklungen bei Topika.

Topical preparations are by far the most frequently used therapeutic or prophylactic pharmaceuticals by dermatologists. Although only a few new active ingredients in topical pharmaceuticals have reached the market in recent years, some innovative galenic concepts and strategies considering the intrinsic effect of topical preparations have been developed, and it is quite certain that we can count on more genuine innovations in the near future. In particular small molecules, but also biological drugs, can be expected to be delivered by topical preparations, especially for inflammatory diseases. Also, we await innovative strategies for the substitution or regulation of the physicochemical and microbiological barrier function of the skin, including completely new options relating to the application of ribonucleic acid derivatives or their inhibitors aiming at influencing gene expression. Overall, it can be stated that the potential of epicutaneous application will take shape in modern vehicle strategies and procedures that deploy the intrinsic effect of topical preparations and that progress in biotechnology and physical chemistry will become increasingly relevant in practice.

Palliative analgesia with topical sevoflurane in cancer-related skin ulcers: a case report.

A Caucasian 39-year-old male patient with a poorly-differentiated infiltrating epidermoid penile carcinoma with urethral invasion was diagnosed. The patient received concomitant adjuvant chemotherapy with radiotherapy in the palliative setting, which produced painful ulceration of tumour lesions at loco-regional level (Numerical Rate Scale, NRS=9). The patient consented for treatment with direct topical sevoflurane instillations, at initial doses of 1 mL/cm2 of ulcerated area, as per unit protocol. The local use of undiluted sevoflurane achieved a marked reduction of the pain score in both nociceptive and irruptive pains (average NRS=3 immediately post-application). This improvement was corroborated by a decline in total morphine needs, any adverse events associated with major opiates. PGI-I and CGI-I scales were used before and after treatment with topical sevoflurane to assess patient and clinician perceptions of improvement in the quality of life. The pharmacy of our hospital had the responsibility to elaborate pre-loaded syringes with sevoflurane so that the patient was instilled simply and comfortably.

Essential Oils and Isolated Terpenes in Nanosystems Designed for Topical Administration: A Review.

Essential oils are natural products with a complex composition. Terpenes are the most common class of chemical compounds present in essential oils. Terpenes and the essential oils containing them are widely used and investigated by their pharmacological properties and permeation-enhancing ability. However, many terpenes and essential oils are sensitive to environmental conditions, undergoing volatilization and chemical degradation. In order to overcome the chemical instability of some isolated terpenes and essential oils, the encapsulation of these compounds in nanostructured systems (polymeric, lipidic, or molecular complexes) has been employed. In addition, nanoencapsulation can be of interest for pharmaceutical applications due to its capacity to improve the bioavailability and allow the controlled release of drugs. Topical drug administration is a convenient and non-invasive administration route for both local and systemic drug delivery. The present review focuses on describing the current status of research concerning nanostructured delivery systems containing isolated terpenes and/or essential oils designed for topical administration and on discussing the use of terpenes and essential oils either for their biological activities or as permeation enhancers in pharmaceutic formulations.

Enhanced Irrigant Delivery to the Ethmoid Sinuses Directly Following Ethmoid Punch Sinusotomy.

OBJECTIVES: Ethmoid punch sinusotomy (EPS) is a feasible treatment for ethmoid sinusitis in a subset of chronic rhinosinusitis (CRS) patients per a recent report. This adjunctive work investigates the technical characteristics of EPS and determines if EPS measurably alters the topical delivery of irrigant into the ethmoid sinuses in a cadaveric model. METHODS: The sinonasal cavities of 10 human cadaver heads were irrigated with a solution containing methylene blue and radio-opaque contrast prior to and following EPS. Procedural characteristics and irrigant distribution were assessed by endoscopy and computed tomography. RESULTS: Forty EPS procedures were performed through the ethmoid bulla and basal lamella. Compared to controls, EPS enhanced dye distribution into the anterior (90% vs 35%, P < .004) and posterior (90% vs 35%, P < .002) ethmoid sinuses, representing a 157% increase for each of these sites. Contrast was detected in a higher proportion of anterior (65% vs 5%, P < .001) and posterior (60% vs 0%, P < .001) ethmoid sinuses. Endoscopically guided catheter instillation of contrast through the EPS sites achieved radiotracer distribution throughout the ethmoid complex. CONCLUSIONS: Ethmoid punch sinusotomy sites can be reliably created via micro-minimally invasive procedures. Ethmoid punch sinusotomy improves irrigant delivery to the ethmoid sinuses, providing mechanistic understanding for the clinical outcomes observed in CRS patients.

Efficacy and safety of topical sevoflurane in the treatment of chronic skin ulcers.

PURPOSE: Results of efficacy and safety assessments of topical sevoflurane use in patients with long-term treatment-refractory vascular ulcers are reported. METHODS: Patients were randomly assigned to receive sevoflurane instillations (1 mL per cm2 of ulcer area 1-4 times daily) plus standard wound care (ulcer cleaning, debridement, and dressing changes) or standard care only. Topical sevoflurane was initiated during hospitalization, with self- or nurse-administered instillations continued after discharge. Study participants were evaluated at least once weekly for 1 month and then every 2 weeks for up to 90 days. The primary efficacy measures were debridement-related and overall pain (assessed using a 10-point visual analog scale), daily opioid use, and ulcer size; secondary measures were patient and clinician impressions of improvement and ulcer-related admissions during treatment. The primary safety endpoint was intolerable sevoflurane-related adverse effects. RESULTS: Compared with the group receiving standard care alone (n = 5), the sevoflurane group (n = 10) had significant (p = 0.001) reductions in mean ± S.D. scores for debridement-related pain on day 1 of treatment and at subsequent time points; the sevoflurane group also had significant reductions in overall pain, daily opioid use, and ulcer size. Outcomes in terms of patient- and clinician-rated improvement and emergency admissions also favored the sevoflurane group. Mild localized reddening in the area surrounding ulcers occurred in 4 sevoflurane-treated patients. CONCLUSION: Direct application of sevoflurane onto vascular ulcers resulted in an intense and long-lasting analgesia and was associated with a progressive reduction of ulcer size.

Gentamicin-Impregnated Collagen Sponge: Effectiveness in Preventing Sternal Wound Infection in High-Risk Cardiac Surgery.

Sternal wound infections represent one of the most frequent complications after cardiac surgery and are associated with high postoperative mortality. Several preventive methods have been introduced, and recently, gentamicin-impregnated collagen sponges (GICSs) have shown a promising effect in reducing the incidence of this type of complications. Gentamicin is an aminoglycoside antibiotic that has been widely used to treat infections caused by multiresistant bacteria; despite its effectiveness, its systemic use carries a risk of toxicity. GICSs appear to overcome this side effect, topically delivering high antibiotic concentrations to the wound and thus reducing the toxic-related events. Although several retrospective analyses and randomized controlled trials have studied the use of GICSs in cardiac surgery, conclusions regarding their efficacy in preventing sternal wound infection are inconsistent. We have reviewed the current literature focusing on high-risk patients.

Systemic and Topical Use of Tranexamic Acid in Spinal Surgery: A Systematic Review.

Study Design Combination of narrative and systematic literature reviews. Objectives Massive perioperative blood loss in complex spinal surgery often requires blood transfusions and can negatively affect patient outcome. Systemic use of the antifibrinolytic agent tranexamic acid (TXA) has become widely used in the management of surgical bleeding. We review the clinical evidence for the use of intravenous TXA as a hemostatic agent in spinal surgery and discuss the emerging role for its complementary use as a topical agent to reduce perioperative blood loss from the surgical site. Through a systematic review of published and ongoing investigations on topical TXA for spinal surgery, we wish to make spine practitioners aware of this option and to suggest opportunities for further investigation in the field. Methods A narrative review of systemic TXA in spinal surgery and topical TXA in surgery was conducted. Furthermore, a systematic search (using PRISMA guidelines) of PubMed (MEDLINE), EMBASE, and Cochrane CENTRAL databases as well as World Health Organization International Clinical Trials Registry Platform, ClinicalTrials.gov (National Institutes of Health), and International Standard Randomized Controlled Trial Number registries was conducted to identify both published literature and ongoing clinical trials on topical TXA in spinal surgery. Results Of 1,631 preliminary search results, 2 published studies were included in the systematic review. Out of 285 ongoing clinical trials matching the search criteria, a total of 4 relevant studies were included and reviewed. Conclusion Intravenous TXA is established as an efficacious hemostatic agent in spinal surgery. Use of topical TXA in surgery suggests similar hemostatic efficacy and potentially improved safety as compared with intravenous TXA. For spinal surgery, the literature on topical TXA is sparse but promising, warranting further clinical investigation and consideration as a clinical option in cases with significant anticipated surgical site blood loss.

Localized topical steroid use and central serous retinopathy.

OBJECTIVES: The link between topical steroid use and central serous retinopathy (CSR) is poorly understood as there are a limited number of reported cases, with most cases typically occurring in patients using oral or inhaled steroids. CSR is a common retinal disease that can cause loss of vision as a result of accumulated subretinal fluid leading to localized serous retinal detachments. CSR is associated with systemic steroid use. The objective of this case series and the review was to further understand the relationship between localized topical steroid use and CSR. METHODS: The medical charts of two patients who developed CSR after using topical steroids were reviewed. RESULTS: These cases demonstrate that CSR is associated with consistent topical steroid use to even limited areas of the body. These cases are unique, as other published cases describe patients who used topical steroids either on multiple or larger areas of the body. CONCLUSION: It is critical that dermatologists are aware of this association, and refer patients who develop ocular symptoms after using topical steroids to ophthalmology.

Continuous topical drug delivery using osmotic pump in animal cochlear implant model: Continuous steroid delivery is effective for hearing preservation.

CONCLUSIONS: Continuous topical drug delivery using an osmotic pump is an effective supplementary technique for hearing preservation after cochlear implantation, as demonstrated in a guinea pig model. OBJECTIVE: To evaluate the effect of continuous topical steroid delivery via an osmotic pump in an animal cochlear implant model. METHODS: Twenty-three guinea pigs were used for the study. The animals were divided into three groups: control group (n = 8), simple topical dexamethasone delivery group (sDEXA group, n = 7) and continuous topical dexamethasone delivery group (cDEXA, n = 8). The hearing thresholds of all animals were measured by pre-operative auditory brain stem responses (ABRs) at 2, 8, 16, 24, and 32 kHz. ABRs were re-evaluated after cochlear implantation, and the animals were sacrificed for hematoxylin and eosin staining. RESULTS: The ABR threshold at 1 week post-operatively was significantly lower in the cDEXA group than in the control and sDEXA groups at most frequencies. Threshold shifts from baseline were statistically smaller in the cDEXA group than in the control and sDEXA groups at all frequencies. Histological analysis revealed decreased numbers of multi-nucleated giant cells and thinner histiocyte layers.