Synthesis and assessment of metallic ion migration through a novel calcium carbonate coating for biomedical implants.

Titanium (Ti) implants are commonly regarded as well accepted by the body. However, metal ion release is still a cause for concern. A small decrease in pH, which can be caused by inflammation, may produce a large increase in the corrosion rate of Ti implants. Coating the alloy with a buffer layer could have a significant protective effect. In this study, a calcium carbonate coating was developed on commercially pure Ti and a Ti-6Al-4V alloy through a hydrothermal treatment of previously NaOH-treated surfaces in calcium-citric acid chelate complexes. The results showed that a superstructured calcite coating layer formed on the Ti substrate after treatment at 170°C for 3 hr. The coating was approx. 1 µm thick and covered the substrate surface uniformly. When prolonging the hydrothermal treatment from 5 hr to 24 hr, the rhombohedral structure of calcite was observed in addition to the superstructure of calcite. Dissolution test results showed no significant differences in solution pH between the coated- and un-coated samples. However, the CaCO3 coating reduced by approx. 2-5 times the Ti and V ion release from the substrate as compared to the uncoated material, at pH 4. CaCO3 and hydroxyapatite (HA) coatings gave nonsignificant effects at neutral pH although the HA coating showed a trend for better results at the longer time points. The reduction in metal ion release from the substrate and the buffering ability of the CaCO3 coating encourage further studies on this coating for clinical applications.

Intermittent Catheters for Chronic Urinary Retention: A Health Technology Assessment.

BACKGROUND: People with chronic urinary retention typically require intermittent catheterization. This review evaluates the effectiveness, safety, patient preference, cost-effectiveness, and budget impact of different types of intermittent catheter (IC). Specifically, we compared prelubricated catheters (hydrophilic, gel reservoir) and noncoated catheters, as well as their single use versus reuse (multiple use). METHODS: We performed a systematic literature search and included randomized controlled trials, cohort, and case-control studies that examined any type of single-use versus multiple-use IC, hydrophilic single-use versus noncoated single-use, or gel reservoir single-use versus noncoated single-use. The outcomes of interest were symptomatic urinary tract infection (UTI), hematuria, other serious adverse events, and patient satisfaction. The quality of the body of evidence was examined according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group criteria. We also completed an economic evaluation, using the perspective of the Ontario Ministry of Health and Long-Term Care, to determine the cost-effectiveness of various intermittent catheters used in Ontario. We determined the budget impact of fully and partially funding various intermittent catheters for outpatients with chronic urinary retention. To understand patient experiences with intermittent catheterization, we interviewed 34 adults and parents of children affected by chronic urinary retention. RESULTS: We found 14 randomized controlled trials that met the inclusion criteria. When comparing any type of single-use or multiple-use IC, we found no difference in UTI (RR = 0.98, 95% CI 0.70-1.39), hematuria, or serious adverse events, and inconclusive evidence on patient satisfaction.Our meta-analysis of studies on people living in the community showed that hydrophilic ICs may result in fewer UTIs than single-use noncoated ICs, but given the nature of the studies, we were uncertain about this conclusion.The nature of the available evidence also did not allow us to make definitive conclusions regarding whether one type of catheter was likely to result in less hematuria, fewer serious adverse events, or greater patient satisfaction.Our economic evaluation found that owing to small differences in quality-adjusted life-years and moderate to large incremental cost differences, the lowest-cost ICs-noncoated multiple-use (using one catheter per week or one catheter per day)-have the highest probability of being cost-effective. In a subpopulation of those clinically advised not to reuse ICs, single-use noncoated ICs have the highest probability of being cost-effective. As current funding is limited in the outpatient setting, publicly funding noncoated multiple-use catheters (one per day) would result in a total additional cost of $93 million over the first 5 years. People who use ICs reported that the high ongoing cost of purchasing catheters was a financial burden. Almost all said they would prefer not to reuse catheters sold as "single use" but could not afford to do so. CONCLUSIONS: Given the overall low quality of evidence in available studies, we are uncertain whether any specific type of IC (coated or noncoated, single- or multiple-use) significantly reduces symptomatic UTI, hematuria, or other serious adverse clinical events, or whether a specific type improves patient satisfaction. Therefore, the lowest-cost IC is likely the most cost-effective.

A prospective intra-individual evaluation of silk compared to Biobrane for the treatment of superficial burns of the hand and face.

INTRODUCTION: An ever-increasing number of commercially available dressings have been applied to treat superficial burns with the aim to reduce pain and inflammation and lead to a fast wound healing and scar reduction. Nevertheless the search for cheap and effective wound dressing proceeds. Dressilk® consisting of silkworm silk showed good results for wound healing in regards to scarring, biocompatibility and reduction of inflammation and pain. Therefore it seemed to be an interesting product for the treatment of superficial burns. METHODS: In a prospective intra-individual study the healing of superficial burns was evaluated after the treatment with Dressilk® and Biobrane® in 30 patients with burns of the hand and face. During wound healing pain, active bleeding, exudation, dressing change and inflammation were evaluated using the Verbal Rating Scale 1-10. Three months later scar appearance was assessed by VSS (Vancouver Scar Scale) and POSAS (Patient and Observer Scar Scale). RESULTS: With regard to re-epithelialization, pain, inflammation and acute bleeding both dressings were equivalent. High subjective satisfaction rates were reported for both Dressilk® and Biobrane® dressings in regard to comfort and mobility of the face. Biobrane®, applied as a glove was subjectively preferred for burns of the hand. Regarding their cost efficiency Dressilk® was clearly superior to Biobrane®. Long-term results were similar. CONCLUSION: The "ideal" wound dressing maximizes patients' comfort while reducing pain and promoting wound healing. Dressilk® and Biobrane® both provided an effective and safe healing environment, showing low overall complication rates with respect to infection and exudation on superficial burns of the hand and face. Therefore Dressilk®, being clearly superior to Biobrane® in cost efficiency is an interesting alternative especially for the treatment of superficial burns of faces.

[Local haemostasis with an adhesive cyanoacrylate-coated membrane following tooth extraction in patients under anticoagulant or anti-platelet therapy]. / Hémostase locale par membrane enduite de cyanoacrylate, après avulsions dentaires sous anticoagulants ou anti-agrégants.

OBJECTIVE: Assessment of a local hemostasis with a compressive, extemporaneous gutter glued to the alveolar crest after tooth avulsion in patients under anticoagulant and/or platelet aggregation inhibitors, and economical impact of this technique. MATERIAL AND METHOD: Ninety-seven tooth extractions were performed in patients under AVK and/or anti-platelet drugs. The interventions were consecutive and concerned 251 teeth (138 different alveolar sites). The extraction alveolus was protected by an absorbable oxycellulose membrane coated with sterilized cyanoacrylate adhesive for medical use. This procedure was used with all patients, whatever the hemorrhagic risk (the only inclusion criterion was INR less than 4 for patients under AVK). All procedures were performed under local anesthesia. RESULTS: There was one hemorrhagic complication (0.72%) due to mechanical gutter destruction by an antagonist tooth. The adhesive did not run, there was no tissue necrosis, and no wound infection requiring gutter removal. DISCUSSION: This local hemostasis procedure is reliable. It may be an alternative to substitution of heparin, without or with hospitalization. This procedure, requiring modification of treatment, greatly decreases healthcare costs. Contra-indications include the presence of an antagonist tooth harmful for the gutter, and patients with impaired consciousness or tongue dyspraxia.

A prospective randomised clinical pilot study to compare the effectiveness of Biobrane® synthetic wound dressing, with or without autologous cell suspension, to the local standard treatment regimen in paediatric scald injuries.

BACKGROUND: Scald is the most common cause of burn in children in Australia. The time taken by the burn wound to heal impacts on scar outcome. Commonly scald injuries are treated conservatively; in our unit the practice is that if healing does not occur within 10 days, surgery is used to aid healing with the aim of improving scar outcome. This randomised controlled pilot study compares early treatment regimens to facilitate tissue salvage and reduce the incidence of definitive surgery at 10 days following scald injury. METHODS: All paediatric patients with partial thickness scald injury were clinically assessed between July 1, 2009 and June 30, 2010. A burn of 2% TBSAB or more and deemed not to heal within 10 days, were considered for the trial. These patients were randomised to one of three treatment arms: the local standard treatment (Intrasite™, Acticoat™ and Duoderm(®) dressings every 2-3 days) with surgery at 10 days, Biobrane(®) only or Biobrane(®) and autologous cell suspension using the ReCell(®) kit. The primary outcome was surgery performed after 10 days; secondary outcomes were rates of healing, pain experienced, and scar outcomes. RESULTS: 15% of scald presentations in the 12 month period met the eligibility criteria. 13 patients were recruited into the pilot study; early intervention was associated with a decreased time to healing with fewer dressing changes, less pain and better scar outcomes. CONCLUSION: Investment of surgical resources in the acute stages within 4 days of injury saved on nursing time, dressing, analgesic and scar management costs.

Impact of using triclosan-antibacterial sutures on incidence of surgical site infection.

BACKGROUND: Surgical site infection is a common complication of surgery. Its morbidities range from delayed healing to systemic sepsis. It has impact on the economy and health care resources. METHODS: This study was a prospective, randomized, double-blinded, controlled multicenter study aimed to compare triclosan-coated polyglactin 910 sutures with polyglactin 910 sutures for the reduction of surgical site infections. This article details the results from the Cairo University center. A total of 450 patients who had undergone different surgical procedures were enrolled; 230 were enrolled in the study group and 220 were enrolled in the control group. RESULTS: The study group and the control group were comparable regarding risk factors for surgical site infection. Surgical site infection incidence was 7% in the study group and 15% in the control group (P = .011). The mean extended stay as a result of infection was 3.71 days, with an average cost $91 US per day. CONCLUSIONS: Use of the triclosan-coated polyglactin 910 antimicrobial suture lead to reduction of surgical site infection and has an impact on saving health care resources. The triclosan-coated polyglactin 910 antimicrobial suture could save $1,517,727 yearly in this single center.

Advances in microbicide vaginal rings.

Vaginal ring devices capable of providing sustained/controlled release of incorporated actives are already marketed for steroidal contraception and estrogen replacement therapy. In recent years, there has been considerable interest in developing similar ring devices for the administration of microbicidal compounds to prevent vaginal HIV transmission. Intended to be worn continuously, such coitally independent microbicide rings are being developed to maintain effective vaginal microbicide concentrations over many weeks or months, thereby overcoming issues around timing of product application, user compliance and acceptability associated with more conventional semi-solid formulations. In this article, an overview of vaginal ring technologies is presented, followed by a review of recent advances and issues pertaining to their application for the delivery of HIV microbicides. This article forms part of a special supplement on presentations covering intravaginal rings, based on the symposium "Trends in Microbicide Formulations", held on 25 and 26 January 2010, Arlington, VA.

A review of the literature on topical therapies for diabetic foot ulcers. Part 2: Advanced treatments.

Following part one, which presented background to diabetic foot ulcers and the principles thought to explain hard-to-heal wounds, part two of this series reviews the efficacy and cost data indicating that certain wound treatments may be of benefit.

Influence of bioengineered skin substitutes on diabetic foot ulcer and venous leg ulcer outcomes.

This systematic review indicates that bioengineered skin substitutes with a dermal component may improve healing outcomes in diabetic foot ulcers and venous leg ulcers. However, better designed trials with longer follow-up periods are needed.

A rehabilitation hospital's experience with ionic silver Foley catheters.

A small rehabilitation hospital in northern Arkansas had a problem with catheter-associated urinary tract infections (CAUTI). A review of practices and policies provided no reason for the trend. The facility trialed an ionic silver Foley catheter finding that it dramatically reduced the incidence of CAUTI in their patient population.

Current evidence on intermittent catheterization: sterile single-use catheters or clean reused catheters and the incidence of UTI.

PURPOSE: Intermittent catheterization is a commonly prescribed procedure for people with incomplete bladder emptying not managed by other methods. The most frequent complication of intermittent catheterization is urinary tract infection (UTI). It is unclear what strategies, including sterile vs clean catheters or coated vs uncoated PVC catheters, affect the incidence of UTIs. This systematic review summarizes current evidence on the relationship between sterile single-use catheters or clean reused catheters and the incidence of UTIs. SEARCH STRATEGY: The Cochrane Incontinence Group trials register, Medline, EMBASE, CINAHL, and ERIC were searched, plus the reference lists of relevant articles and conference proceedings. Randomized controlled trials comparing at least two different products or methods for intermittent catheterization were included. DATA COLLECTION AND ANALYSIS: Three reviewers assessed the methodological quality of trials and abstracted data. MAIN RESULTS: Of the 13 trials that met the inclusion criteria on intermittent catheterization protocols, there was considerable variation in length of follow-up, definitions of UTI, and numbers of subjects. Attrition was a problem for several studies, and all were underpowered. Several studies were more than 10 years old, and outcome measures were imprecise, making it difficult to draw conclusions on the benefit of one catheterization method over another. CONCLUSIONS: There are no definitive studies illustrating that incidence of UTIs is affected by sterile single-use or coated catheters compared to clean reused catheters. However the current research base is weak and design issues are significant. Based on the current data, it is not possible to state that one catheter method is better than another and further research on the topic is strongly recommended.

Use of Transcyte and dermabrasion to treat burns reduces length of stay in burns of all size and etiology.

BACKGROUND: With the cost of healthcare increasing, greater emphasis is placed on finding better ways to manage burn patients by increasing the quality of care while reducing length of hospital stay (LOS), thereby reducing overall cost. To date, this is the largest study to determine if Transcyte reduces LOS for partial thickness burns of any size or etiology. METHODS: All consecutive patients with deep partial thickness burns from April 2002 to December 2002 were reviewed (n=110) with IRB approval. Ninety-two patients were treated with dermabrasion and Transcyte only. Eighteen patients were treated with a combination of STSG and dermabrasion and Transcyte where appropriate. Our data was compared to the American Burn Association Patient Registry, as reported by Saffle et al. 1995. RESULTS: The data for percent TBSA and LOS are reported as mean+/-S.E.M. One-tailed t-test was used to analyze the data. Significant difference was found in patients who were treated with dermabrasion and Transcyte compared to the population reported by Saffle et al. Patients with 0-19.9% TBSA burn treated with dermabrasion and Transcyte had LOS of 6.1 days versus 9.0 days (p<0.001). Those with 20-39.9% TBSA burn had length of stay of 17.5 days versus 25.5 days. Patients treated with STSG and Transcyte who had 40-59.9% TBSA burn had length of stay of 39.7 days versus 44.6 days. Those treated with dermabrasion and Transcyte alone had length of stay of 31 days. CONCLUSION: This is the first study comparing burns of all sizes treated with dermabrasion and Transcyte with a known population receiving standard therapy. The authors found this new method of managing patients with partial thickness burns to be more efficacious and significantly reduces length of stay compared to traditional management.

Embolization of intracranial aneurysms with hydrogel-coated coils versus inert platinum coils: effects on packing density, coil length and quantity, procedure performance, cost, length of hospital stay, and durability of therapy.

BACKGROUND AND PURPOSE: The durability of aneurysm coil embolization is thought to depend on packing density. The expansile property of hydrogel coating on coils increases volumetric packing per coil length. We describe our experience using hydrogel-coated coils (HydroCoils) compared with inert platinum coils in intracranial aneurysm embolization. METHODS: Fifty aneurysms embolized primarily using HydroCoils from 2003 to 2004 were compared with 57 volume- and shape-matched aneurysms treated with standard platinum coils from 2000 to 2003. Outcome measures included volumetric percentage occlusion (VPO), length and number of coils used, procedure time, fluoroscopy time, contrast volume, coil cost, length of hospital stay, and durability of therapy. RESULTS: Seventeen/26/5 small/medium/large aneurysms treated with HydroCoils were matched with 29/24/4 small/medium/large aneurysms treated with inert platinum. HydroCoil embolization yielded significantly greater VPO (84.8% versus 29.8%; P<0.001), decreased average total coil length used per aneurysm (33.2 versus 44.3 cm), reduced fluoroscopy time (53.2 versus 65.2 minutes; P=0.016), but increased contrast volume used (174.8 versus 112.9 cc; P<0.001). There were no differences in length of hospital stay. Procedure-related morbidity and mortality rates in the HydroCoil cohort were 4% and 0%, respectively. Follow-up angiography at mean 12.3 months revealed lower aneurysm recurrence rates (17% versus 24%; number-needed-to-treat [NNT] 14.3). Initial costs associated with HydroCoil embolization were higher ($5835 versus $4017; P=0.004) but countered by lower retreatment rates (10% versus 17%; NNT 14.3). CONCLUSIONS: HydroCoil embolization achieves greater aneurysm packing density with decreased coil length. Initial durability data favor HydroCoils, with lower recurrence and retreatment rates.

The paclitaxel-eluting stent in percutaneous coronary intervention: Part II. Comparison with the sirolimus-eluting stent, economics, and unanswered questions.

The paclitaxel- and sirolimus-eluting stents are currently the only drug-eluting stents approved for use in the United States. These 2 stents differ in terms of mechanism of drug action, the construct of the stent itself, and the drug delivery polymer. Clinical trials have demonstrated superiority of both paclitaxel- and sirolimus-eluting stents when compared with bare-metal stents in terms of reducing restenosis and the need for target vessel revascularization. Recently published head-to-head trials have not conclusively shown 1 drug-eluting stent to be superior to the other, but have demonstrated more favorable angiographic results with the sirolimus-eluting stent compared with the paclitaxel-eluting stent; however, no significant difference has been demonstrated in clinical outcomes such as myocardial infarction or death. In terms of economics, the paclitaxel-eluting stent is substantially more expensive than the bare-metal stent. However, by significantly reducing the risk of restenosis and need for repeat revascularization, the higher direct cost of the paclitaxel-eluting stent may in theory be offset by lower overall healthcare costs, although economic analyses have yet to definitively establish that the paclitaxel-eluting stent is truly cost-effective. There is still much to be discovered regarding the paclitaxel-eluting stent, specifically the optimal stent design and drug release mechanism, the relative safety and efficacy of the paclitaxel-eluting stent compared with other drug-eluting stents, the long-term effects of the paclitaxel-eluting stent, the ideal antiplatelet regimen to use in patients with a paclitaxel-eluting stent, the safety and efficacy of the paclitaxel-eluting stent in various high-risk patient groups, and the ultimate cost-effectiveness of this device.

Drug-eluting stents: a multidisciplinary success story.

Coronary stenting is the most common form of interventional treatment for symptomatic coronary artery disease. In-stent restenosis following bare metal stent (BMS) placement is the most common cause of procedural failure and occurs as a result of vessel wall trauma secondary to balloon angioplasty and stent deployment that results in an overly aggressive healing response (neointimal hyperplasia) that overgrows the stent lumen and causes vascular narrowing. Drug-eluting stents (DES) are specialized vascular stents capable of delivering drugs to the arterial wall in a controlled manner such that neointimal hyperplasia is reduced or prevented, luminal patency is preserved, coronary blood flow is maintained and the patient is spared a repeat procedure to re-open the vessel. The objectives of the review are to provide an overview of the major contributions that a broad range of disciplines have made to the design and development of drug-eluting stents and to summarize future directions of these fields of research. Engineers and biomaterials scientists have explored relationships between stent design and stent performance and work continues to optimize stent design and biocompatibility of stent biomaterials. Pharmaceutical scientists are continually expanding the range of candidate drugs for pharmacological intervention, and improving the technology using novel coatings to modulate drug release. Clinical scientists are investigating issues such as long-term safety and efficacy, new applications of drug-eluting stents and optimal deployment techniques.

The cost of a hot drink scald.

Approximately 6400 children per year are admitted to UK hospitals for treatment of burns [National Burn Care Review Committee Report (NBCRC). Standards and Strategy for Burn Care: a review of burn care in the British Isles. 2001.]. This paper investigates the financial costs involved in the management of uncomplicated, minor paediatric scalds. Three cases (2-4% TBSA scalds) were studied to quantify consumables used, services required during management and costs obtained from appropriate Purchasing Departments and Directorate Accountants. Management in all cases involved a general anaesthetic for cleaning of wounds, application of BioBrane (Bertek Pharmaceuticals) and dressings, observation on Children's Ward and discharge following wound review at 48 h. The calculated mean average cost per case was pound1850. In the period 01/12/2002-30/11/2003, 144 children were admitted to Frenchay hospital, Bristol, for treatment of a minor burn or scald (less than 10%TBSA). This caseload is therefore estimated to currently cost pound266,400 per year. These findings may facilitate improved planning for future resource allocation and could also contribute evidence towards the cost effectiveness of prevention strategies.

Biobrane in the treatment of burn and scald injuries in children.

Eighty-four children with a burn (n = 7) or scald injury (n = 77), treated with Biobrane, were investigated in a retrospective and clinical study. In most patients (n = 71), the Biobrane was adherent and without any reactions or infections. An infection was seen in 10.7% (9 from 84 patients). Twenty-one of 49 patients of the follow-up had limited scar areas. In scarless healed areas, 54.3% had normopigmentation and 39.1% were hypopigmented. The skin quality of the scars was mostly hypopigmented with a softness between minimal and middle resistance, under 2-mm high, and of normal to pink skin color. Compared with other dressings, Biobrane is no more expensive than others. We conclude that when used on properly selected wounds, Biobrane is an effective and, for the children, less traumatic therapy for superficial partial-thickness burns without increasing the cost of outpatient burn care.

A cost-effectiveness analysis of a hypothetical catheter-based strategy for the detection and treatment of vulnerable coronary plaques with drug-eluting stents.

AIM: Extensive efforts are underway to develop methods for the detection and treatment of vulnerable/high-risk coronary artery plaques. We utilized decision analysis to evaluate the hypothetical clinical benefits and cost-effectiveness of a catheter-based strategy. METHODS AND RESULTS: Currently, stenotic coronary plaques are treated without regard to vulnerability. In a new strategy, vulnerable coronary plaques are detected with a catheter-based test and treated with a drug-eluting stent, regardless of degree of stenosis. A Markov-decision model was developed to compare the new strategy with current practice. Monte Carlo simulations were performed from a societal perspective, costs were converted to year 2003 U.S. dollars, and future costs and outcomes were discounted at 3%. Sensitivity analyses were performed to evaluate the effect of assumptions on variables such as the prevalence of vulnerable plaques and treatment effect. In 60-year-old male patients with coronary stenoses the new strategy would be less expensive and more effective than current practice (37,045 dollars vs 38,257 dollars and 10.23 vs 9.86 quality-adjusted life years (QALYs), respectively). The benefits of the new strategy were robust in sensitivity analyses (e.g., if the prevalence of vulnerable plaques in this patient group was 50% or more and the sensitivity and specificity of the new test were at least 0.80). CONCLUSION: In selected patients with coronary artery stenosis, the detection of vulnerable plaques with a catheter-based test followed by their treatment with a drug-eluting stent could be a less expensive and more effective strategy than current practice. If applied to 1 million such patients in the United States undergoing catheterization, the new strategy would add 370,000 QALYs and save 1.2 billion dollars per year.

Self-expanding metal stents versus plastic prostheses in the palliation of malignant dysphagia: long-term outcome of 153 consecutive patients.

BACKGROUND: Malignant dysphagia due to esophagogastric cancer is associated with poor overall prognosis. Placements of self-expandable metal stents or plastic tubes are established methods as palliative treatment options. As an alternative and/or complementary therapy, radiologic techniques (external beam radiation/brachytherapy) and locally endoscopic techniques (laser, APC-beamer, PDT) are often used. STUDY AND GOALS: Retrospective trial of 153 patients treated in our department between 1993 and 2001. Forty-five patients received a plastic tube (Group A) and 108 patients were treated with metal stents (Group B). Both groups were compared for improvement of dysphagia score, survival, recurrent dysphagia and complications. RESULTS: Stent placement was successful in 41 of 45 (93%) patients of Group A and 107 of 108 (99%) of Group B. The median dysphagia score improved significantly in Group A (from 3.03 to 1.55, P = 0.010) and Group B (from 2.77 to 1.44, P = 0.009). Recurrent dysphagia was noted in 12 of 45 (27%) patients of Group A and 27 of 108 (25%) patients of Group B. Median survival time after stent insertion was 78 days (Group A) and 113 days (Group B). Overall complications occurred in 15 of 45 (33%) patients of Group A and 28 of 108 (26%) patients of Group B. However, significantly (P = 0.05) more major complications were seen in Group A than in Group B (22% vs. 9%). CONCLUSIONS: Our results indicate a marginal clinical benefit for metal stents versus plastic tubes in malignant dysphagia in the long run. However, metal stents seem to be safer and associated with a prolonged improvement of dysphagia score.