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The Cochrane Database of Systematic... May 2013Venous leg ulcers are a common and recurring type of chronic or complex wound that are associated with considerable cost to patients and to healthcare... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Venous leg ulcers are a common and recurring type of chronic or complex wound that are associated with considerable cost to patients and to healthcare providers. Primary wound contact dressings are usually applied beneath compression devices with the aim of aiding healing. Foam dressings are used frequently, and a variety of foam products is available on the market. The evidence base to guide dressing choice, however, is sparse.
OBJECTIVES
To determine the effects of foam dressings on the healing of venous leg ulcers.
SEARCH METHODS
In October 2012 we searched The Cochrane Wounds Group Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); the Database of Abstracts of Reviews of Effects (DARE) (The Cochrane Library); the Economic Evaluation Database (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; EBSCO CINAHL. There were no restrictions based on language or date of publication.
SELECTION CRITERIA
We included published or unpublished randomised controlled trials (RCTs) that evaluated the effects of any type of foam dressing in the treatment of venous ulcers.
DATA COLLECTION AND ANALYSIS
Two review authors independently performed study selection, data extraction and risk of bias assessment. Meta-analysis was undertaken when deemed feasible and appropriate.
MAIN RESULTS
Twelve RCTs (1023 participants) reporting 14 comparisons were included in this review. There was no difference in healing outcomes between hydrocellular foam dressings and polyurethane foam dressings (three RCTs). Pooled data across five RCTs (418 participants) showed no statistically significant difference between foam dressings and hydrocolloid dressings in the proportion of ulcers healed at 12 to 16 weeks (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.81 to 1.22). No statistically significant between-group differences in healing outcomes were detected when foam dressings were compared with: paraffin gauze (two RCTs); hydrocapillary dressing (one RCT); knitted viscose dressing (one RCT); and protease modulating matrix (one RCT). No statistically significant between-group differences in the proportion of participants experiencing adverse events were detected when hydrocellular foam dressings were compared with polyurethane foam dressings, or when foam dressings were compared with hydrocapillary, hydrocolloid, or knitted viscose dressings (one RCT for each comparison). Six RCTs were considered as being at overall high risk of bias, and the remaining six RCTs were considered to be at overall unclear risk of bias. No included RCT had an overall low risk of bias.
AUTHORS' CONCLUSIONS
The current evidence base does not suggest that foam dressings are more effective in the healing of venous leg ulcers than other wound dressing treatments. The evidence in this area is of low quality. Further evidence is required from well-designed and rigorously-conducted RCTs, that employ methods to minimise bias and report them clearly, before any definitive conclusions can be made regarding the efficacy of foam dressings in the management of venous leg ulcers.
Topics: Bandages, Hydrocolloid; Humans; Polyurethanes; Randomized Controlled Trials as Topic; Varicose Ulcer; Wound Healing
PubMed: 23728697
DOI: 10.1002/14651858.CD009907.pub2 -
EFORT Open Reviews Apr 2023The biomechanical characteristics of different techniques to perform the modified Lapidus procedure are controversial, discussing the issue of stability, rigidity, and... (Review)
Review
PURPOSE
The biomechanical characteristics of different techniques to perform the modified Lapidus procedure are controversial, discussing the issue of stability, rigidity, and compression forces from a biomechanical point of view. The aim of this systematic review was to investigate the available options to identify whether there is a procedure providing superior biomechanical results.
METHODS
A comprehensive literature search was performed by screening PubMed, Embase, and Cochrane databases until September 2021. There was a wide heterogeneity of the available data in the different studies. Load to failure, stiffness, and compression forces were summarized and evaluated.
RESULTS
Seventeen biomechanical studies were retrieved - ten cadaveric and seven polyurethane foam (artificial bone) studies. Fixation methods ranged from the classic crossed screw approach (n = 5) to plates (dorsomedial and plantar) with or without compression screws (n = 11). Newer implants such as intramedullary stabilization screws (n = 1) and memory alloy staples (n = 2) were investigated.
CONCLUSION
The two crossed screws construct is still a biomechanical option; however, according to this systematic review, there is strong evidence that a plate-screw construct provides superior stability especially in combination with a compression screw. There is also evidence about plate position and low evidence about compression screw position. Plantar plates seem to be advantageous from a biomechanical point of view, whereas compression screws could be better when positioned outside the plate. Overall, this review suggests the biomechanical advantages of using a combination of locking plates with a compression screw.
PubMed: 37097047
DOI: 10.1530/EOR-22-0069 -
The Journal of Vascular Access Jan 2024Short peripheral catheters (SPCs) are used to provide intravenous therapies in hospitalized patients. Recently, the category of SPC has become more complex, with the...
BACKGROUND
Short peripheral catheters (SPCs) are used to provide intravenous therapies in hospitalized patients. Recently, the category of SPC has become more complex, with the introduction in clinical practice of "integrated" SPCs (ISPCs), renewed regarding the material (polyurethane rather than polytetrafluoroethylene) and design (large wing; pre-assembled extension; preassembled needle-free connector (NFC)).
METHODS
This systematic review and meta-analysis aimed to analyze randomized controlled trials (RCTs) and quasi-randomized studies in hospitalized patients, analyzing the risk of overall catheter failure as well as the risk of each type of complication (occlusion, infiltration, thrombophlebitis, and dislodgement) for ISPCs compared to non-integrated SPCs. These systematic review and meta-analysis were registered on PROSPERO (CRD42022322970).
DATA SOURCES
We searched PUBMED, EMBASE, and the Cochrane Controlled Clinical Trials register from April to November 2022.
RESULTS: INCLUDED STUDIES
The research identified 1260 articles. After the abstract review, 13 studies were included for full manuscript review and, after that, six papers (4727 patients) were included in the meta-analysis.
DESCRIPTION OF THE EFFECT
We found a significantly reduced risk of catheter failure (pooling all complications) for ISPCs compared to SPCs ( = 0.002 RR 0.65; 95% CI 0.63-0.9). A significant reduction in the risks of occlusion ( = 0.007 RR 0.72; 95% CI 0.56-0.92) was observed. As regards the risk of infiltration, thrombophlebitis, and dislodgement, the analysis showed a trend in favor of ISPCs, though not statistically significant (respectively = 0.2 RR 0.84; 95% CI 0.64-1.1; = 0.25 RR 0.91; 95% CI 0.78-1.07; = 0.06 RR 0.72; 95% CI 0.52-1.01).
CONCLUSIONS
ISPCs significantly reduce the risks of catheter failure (overall complications) and occlusion. More RCTs are needed to understand if the preassembled ISPC is better than the composted closed system (non-integrated SPC + extension line + NFC).
PubMed: 38166435
DOI: 10.1177/11297298231218468 -
The Cochrane Database of Systematic... Feb 2018Femoro-popliteal bypass is implemented to save limbs that might otherwise require amputation, in patients with ischaemic rest pain or tissue loss; and to improve walking... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Femoro-popliteal bypass is implemented to save limbs that might otherwise require amputation, in patients with ischaemic rest pain or tissue loss; and to improve walking distance in patients with severe life-limiting claudication. Contemporary practice involves grafts using autologous vein, polytetrafluoroethylene (PTFE) or Dacron as a bypass conduit. This is the second update of a Cochrane review first published in 1999 and last updated in 2010.
OBJECTIVES
To assess the effects of bypass graft type in the treatment of stenosis or occlusion of the femoro-popliteal arterial segment, for above- and below-knee femoro-popliteal bypass grafts.
SEARCH METHODS
For this update, the Cochrane Vascular Information Specialist searched the Vascular Specialised Register (13 March 2017) and CENTRAL (2017, Issue 2). Trial registries were also searched.
SELECTION CRITERIA
We included randomised trials comparing at least two different types of femoro-popliteal grafts for arterial reconstruction in patients with femoro-popliteal ischaemia. Randomised controlled trials comparing bypass grafting to angioplasty or to other interventions were not included.
DATA COLLECTION AND ANALYSIS
Both review authors (GKA and CPT) independently screened studies, extracted data, assessed trials for risk of bias and graded the quality of the evidence using GRADE criteria.
MAIN RESULTS
We included nineteen randomised controlled trials, with a total of 3123 patients (2547 above-knee, 576 below-knee bypass surgery). In total, nine graft types were compared (autologous vein, polytetrafluoroethylene (PTFE) with and without vein cuff, human umbilical vein (HUV), polyurethane (PUR), Dacron and heparin bonded Dacron (HBD); FUSION BIOLINE and Dacron with external support). Studies differed in which graft types they compared and follow-up ranged from six months to 10 years.Above-knee bypassFor above-knee bypass, there was moderate-quality evidence that autologous vein grafts improve primary patency compared to prosthetic grafts by 60 months (Peto odds ratio (OR) 0.47, 95% confidence interval (CI) 0.28 to 0.80; 3 studies, 269 limbs; P = 0.005). We found low-quality evidence to suggest that this benefit translated to improved secondary patency by 60 months (Peto OR 0.41, 95% CI 0.22 to 0.74; 2 studies, 176 limbs; P = 0.003).We found no clear difference between Dacron and PTFE graft types for primary patency by 60 months (Peto OR 1.67, 95% CI 0.96 to 2.90; 2 studies, 247 limbs; low-quality evidence). We found low-quality evidence that Dacron grafts improved secondary patency over PTFE by 24 months (Peto OR 1.54, 95% CI 1.04 to 2.28; 2 studies, 528 limbs; P = 0.03), an effect which continued to 60 months in the single trial reporting this timepoint (Peto OR 2.43, 95% CI 1.31 to 4.53; 167 limbs; P = 0.005).Externally supported prosthetic grafts had inferior primary patency at 24 months when compared to unsupported prosthetic grafts (Peto OR 2.08, 95% CI 1.29 to 3.35; 2 studies, 270 limbs; P = 0.003). Secondary patency was similarly affected in the single trial reporting this outcome (Peto OR 2.25, 95% CI 1.24 to 4.07; 236 limbs; P = 0.008). No data were available for 60 months follow-up.HUV showed benefits in primary patency over PTFE at 24 months (Peto OR 4.80, 95% CI 1.76 to 13.06; 82 limbs; P = 0.002). This benefit was still seen at 60 months (Peto OR 3.75, 95% CI 1.46 to 9.62; 69 limbs; P = 0.006), but this was only compared in one trial. Results were similar for secondary patency at 24 months (Peto OR 4.01, 95% CI 1.44 to 11.17; 93 limbs) and at 60 months (Peto OR 3.87, 95% CI 1.65 to 9.05; 93 limbs).We found HBD to be superior to PTFE for primary patency at 60 months for above-knee bypass, but these results were based on a single trial (Peto OR 0.38, 95% CI 0.20 to 0.72; 146 limbs; very low-quality evidence). There was no difference in primary patency between HBD and HUV for above-knee bypass in the one small study which reported this outcome.We found only one small trial studying PUR and it showed very poor primary and secondary patency rates which were inferior to Dacron at all time points.Below-knee bypassFor bypass below the knee, we found no graft type to be superior to any other in terms of primary patency, though one trial showed improved secondary patency of HUV over PTFE at all time points to 24 months (Peto OR 3.40, 95% CI 1.45 to 7.97; 88 limbs; P = 0.005).One study compared PTFE alone to PTFE with vein cuff; very low-quality evidence indicates no effect to either primary or secondary patency at 24 months (Peto OR 1.08, 95% CI 0.58 to 2.01; 182 limbs; 2 studies; P = 0.80 and Peto OR 1.22, 95% CI 0.67 to 2.23; 181 limbs; 2 studies; P = 0.51 respectively)Limited data were available for limb survival, and those studies reporting on this outcome showed no clear difference between graft types for this outcome. Antiplatelet and anticoagulant protocols varied extensively between trials, and in some cases within trials.The overall quality of the evidence ranged from very low to moderate. Issues which affected the quality of the evidence included differences in the design of the trials, and differences in the types of grafts they compared. These differences meant we were often only able to combine and analyse small numbers of participants and this resulted in uncertainty over the true effects of the graft type used.
AUTHORS' CONCLUSIONS
There was moderate-quality evidence of improved long-term (60 months) primary patency for autologous vein grafts when compared to prosthetic materials for above-knee bypasses. In the long term (two to five years) there was low-quality evidence that Dacron confers a small secondary patency benefit over PTFE for above-knee bypass. Only very low-quality data exist on below-knee bypasses, so we are uncertain which graft type is best. Further randomised data are needed to ascertain whether this information translates into an improvement in limb survival.
Topics: Arterial Occlusive Diseases; Blood Vessel Prosthesis Implantation; Femoral Artery; Humans; Intermittent Claudication; Leg; Polyethylene Terephthalates; Polytetrafluoroethylene; Popliteal Artery; Randomized Controlled Trials as Topic; Saphenous Vein; Transplantation, Autologous; Umbilical Veins; Vascular Surgical Procedures
PubMed: 29429146
DOI: 10.1002/14651858.CD001487.pub3 -
The Cochrane Database of Systematic... Sep 2021Each year, in high-income countries alone, approximately 100 million people develop scars. Excessive scarring can cause pruritus, pain, contractures, and cosmetic... (Review)
Review
BACKGROUND
Each year, in high-income countries alone, approximately 100 million people develop scars. Excessive scarring can cause pruritus, pain, contractures, and cosmetic disfigurement, and can dramatically affect people's quality of life, both physically and psychologically. Hypertrophic scars are visible and elevated scars that do not spread into surrounding tissues and that often regress spontaneously. Silicone gel sheeting (SGS) is made from medical-grade silicone reinforced with a silicone membrane backing and is one of the most commonly used treatments for hypertrophic scars.
OBJECTIVES
To assess the effects of silicone gel sheeting for the treatment of hypertrophic scars in any care setting.
SEARCH METHODS
In April 2021 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) that enrolled people with any hypertrophic scars and assessed the use of SGS.
DATA COLLECTION AND ANALYSIS
Two review authors independently performed study selection, 'Risk of bias' assessment, data extraction and GRADE assessment of the certainty of evidence. We resolved initial disagreements by discussion, or by consulting a third review author when necessary.
MAIN RESULTS
Thirteen studies met the inclusion criteria. Study sample sizes ranged from 10 to 60 participants. The trials were clinically heterogeneous with differences in duration of follow-up, and scar site. We report 10 comparisons, SGS compared with no SGS treatment and SGS compared with the following treatments: pressure garments; silicone gel; topical onion extract; polyurethane; propylene glycol and hydroxyethyl cellulose sheeting; Kenalog injection; flashlamp-pumped pulsed-dye laser; intense pulsed light and Gecko Nanoplast (a silicone gel bandage). Six trials had a split-site design and three trials had an unclear design (resulting in a mix of paired and clustered data). Included studies reported limited outcome data for the primary review outcomes of severity of scarring measured by health professionals and adverse events (limited data reported by some included studies, but further analyses of these data was not possible) and no data were reported for severity of scarring reported by patients. For secondary outcomes some pain data were reported, but health-related quality of life and cost effectiveness were not reported. Many trials had poorly-reported methodology, meaning the risk of bias was unclear. We rated all evidence as being either of low or very low certainty, often because of imprecision resulting from few participants, low event rates, or both, all in single studies. SGS compared with no SGS Seven studies with 177 participants compared SGS with no SGS for hypertrophic scars. Two studies with 31 participants (32 scars) reported severity of scarring assessed by health professionals, and it is uncertain whether there is a difference in severity of scarring between the two groups (mean difference (MD) -1.83, 95% confidence interval (CI) -3.77 to 0.12; very low-certainty evidence, downgraded once for risk of bias, and twice for serious imprecision). One study with 34 participants suggests SGS may result in a slight reduction in pain level compared with no SGS treatment (MD -1.26, 95% CI -2.26 to -0.26; low-certainty evidence, downgraded once for risk of bias and once for imprecision). SGS compared with pressure garments One study with 54 participants was included in this comparison. The study reported that SGS may reduce pain levels compared with pressure garments (MD -1.90, 95% CI -2.99 to -0.81; low-certainty evidence, downgraded once for risk of bias and once for imprecision). SGS compared with silicone gel One study with 32 participants was included in this comparison. It is unclear if SGS impacts on severity of scarring assessed by health professionals compared with silicone gel (MD 0.40, 95% CI -0.88 to 1.68; very low-certainty evidence, downgraded once for risk of bias, twice for imprecision). SGS compared with topical onion extract One trial (32 participants) was included in this comparison. SGS may slightly reduce severity of scarring compared with topical onion extract (MD -1.30, 95% CI -2.58 to -0.02; low-certainty evidence, downgraded once for risk of bias, and once for imprecision). SGS compared with polyurethane One study with 60 participants was included in this comparison. It is unclear if SGS impacts on the severity of scarring assessed by health professionals compared with polyurethane (MD 0.50, 95% CI -2.96 to 3.96; very low-certainty evidence, downgraded once for risk of bias, and twice for imprecision). SGS compared with self-adhesive propylene glycol and hydroxyethyl cellulose sheeting One study with 38 participants was included in this comparison. It is uncertain if SGS reduces pain compared with self-adhesive propylene glycol and hydroxyethyl cellulose sheeting (MD -0.12, 95% CI -0.18 to -0.06). This is very low-certainty evidence, downgraded once for risk of bias, once for imprecision and once for indirectness. SGS compared with Gecko Nanoplast One study with 60 participants was included in this comparison. It is unclear if SGS impacts on pain compared with Gecko Nanoplast (MD 0.70, 95% CI -0.28 to 1.68; very low-certainty evidence, downgraded once for risk of bias and twice for imprecision. There was a lack of reportable data from the other three comparisons of SGS with Kenalog injection, flashlamp-pumped pulsed-dye laser or intense pulsed light.
AUTHORS' CONCLUSIONS
There is currently limited rigorous RCT evidence available about the clinical effectiveness of SGS in the treatment of hypertrophic scars. None of the included studies provided evidence on severity of scarring validated by participants, health-related quality of life, or cost effectiveness. Reporting was poor, to the extent that we are not confident that most trials are free from risk of bias. The limitations in current RCT evidence suggest that further trials are required to reduce uncertainty around decision-making in the use of SGS to treat hypertrophic scars.
Topics: Bandages; Cicatrix, Hypertrophic; Humans; Silicone Gels; Wound Healing
PubMed: 34564840
DOI: 10.1002/14651858.CD013357.pub2 -
The Cochrane Database of Systematic... Apr 2012Faecal incontinence is a distressing disorder with high social stigma. Not all people with faecal incontinence can be cured with conservative or surgical treatment and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Faecal incontinence is a distressing disorder with high social stigma. Not all people with faecal incontinence can be cured with conservative or surgical treatment and they may need to rely on containment products, such as anal plugs.
OBJECTIVES
To assess the performance of different types of anal plugs for containment of faecal incontinence.
SEARCH METHODS
We searched the Cochrane Incontinence Group Specialised Register (searched 29 February 2012). Reference lists of identified trials were searched and plugs manufacturers were contacted for trials. No language or other limitations were imposed.
SELECTION CRITERIA
Types of studies: This review was limited to randomised and quasi-randomised controlled trials (including crossovers) of anal plug use for the management of faecal incontinence.
TYPES OF PARTICIPANTS
Children and adults with faecal incontinence.Types of interventions: Any type of anal plug. Comparison interventions might include no treatment, conservative (physical) treatments, nutritional interventions, surgery, pads and other types or sizes of plugs.
DATA COLLECTION AND ANALYSIS
Two reviewers independently assessed methodological quality and extracted data from the included trials. Authors of all included trials were contacted for clarification concerning methodological issues.
MAIN RESULTS
Four studies with a total of 136 participants were included. Two studies compared the use of plugs versus no plugs, one study compared two sizes of the same brand of plug, and one study compared two brands of plugs. In all included studies there was considerable dropout (in total 48 (35%) dropped out before the end of the study) for varying reasons. Data presented are thus subject to potential bias. 'Pseudo-continence' was, however, achieved by some of those who continued to use plugs, at least in the short-term. In a comparison of two different types of plug, plug loss was less often reported and overall satisfaction was greater during use of polyurethane plugs than polyvinyl-alcohol plugs.
AUTHORS' CONCLUSIONS
The available data were limited and incomplete, and not all pre-specified outcomes could be evaluated. Consequently, only tentative conclusions are possible. The available data suggest that anal plugs can be difficult to tolerate. However, if they are tolerated they can be helpful in preventing incontinence. Plugs could then be useful in a selected group of people either as a substitute for other forms of management or as an adjuvant treatment option. Plugs come in different designs and sizes; the review showed that the selection of the type of plug can impact on its performance.
Topics: Adult; Child; Equipment Design; Fecal Incontinence; Humans; Patient Dropouts; Randomized Controlled Trials as Topic; Tampons, Surgical
PubMed: 22513927
DOI: 10.1002/14651858.CD005086.pub3 -
Journal of Advanced Nursing Dec 2003Gauze and tape or transparent polyurethane film dressings such as Tegaderm, Opsite or Opsite IV3000 are the most common types of dressing used to secure central venous... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Gauze and tape or transparent polyurethane film dressings such as Tegaderm, Opsite or Opsite IV3000 are the most common types of dressing used to secure central venous catheters (CVCs). Currently, there are no clear guidelines as to which type of dressing is the most appropriate.
AIMS
To identify whether there are any differences between gauze and tape and/or transparent polyurethane film dressings in the incidence of CVC-related infection, catheter-related sepsis, catheter security, tolerance to dressing material, dressing condition and ease of application in hospitalized patients.
METHODS
The Cochrane Controlled Trials Register and Medline, Embase and CancerLit databases were searched to identify any controlled trials comparing the effects of gauze and tape and/or transparent polyurethane dressings on CVCs. Additional references were sought from published and non-published literature. Twenty-three studies were reviewed. Data were extracted independently from each paper by two members of the review team and results compared. Differences were resolved either by consensus or referral to a third person. Authors were contacted for missing information.
RESULTS
Of the 23 studies reviewed, 15 were excluded. Of the remaining eight, data were available for meta-analysis from six studies. Of the six included studies, two compared gauze and tape with Opsite IV3000, two compared Opsite with Opsite IV3000, one compared Tegaderm with Opsite IV3000, and one compared Tegaderm with Opsite.
CONCLUSIONS
There was no evidence of any difference in the incidence of infectious complications between any of the dressing types compared in this review. Each of these comparisons was based on no more than two studies and all of these studies reported data from a small patient sample. Therefore it is unlikely that any of these comparisons would have had sufficient power to detect any differences between groups.
Topics: Bandages; Catheterization, Central Venous; Humans; Infections; Occlusive Dressings; Randomized Controlled Trials as Topic; Risk Factors
PubMed: 14651685
DOI: 10.1046/j.0309-2402.2003.02852.x -
International Orthodontics Sep 2012Elastomeric chains are one of several devices used to provide force for orthodontic tooth movement, but the force they exert diminishes over time and can thus be... (Review)
Review
INTRODUCTION
Elastomeric chains are one of several devices used to provide force for orthodontic tooth movement, but the force they exert diminishes over time and can thus be difficult to control. The objective of this investigation was to provide a systematic review of publications pertinent to force decay in orthodontic elastomeric chains.
MATERIALS AND METHODS
A systematic review was performed via electronic querying of multiple databases for the period 1970-2011. Queries were limited to a set of specific keywords in two languages (English and French). Five main reviews were consulted manually to identify relevant publications. Two investigators sorted out those studies that complied with selection criteria.
RESULTS AND DISCUSSION
A total of 53 studies were found to be relevant to force decay in elastomeric chains, including 22 on force decay over time, seven on the force consequences of pre-stretching, 12 on the impact of the environment on the force delivered, and 11 on clinical efficacy.
CONCLUSION
The force delivered by elastomeric chains decays rapidly over time, affecting their mechanical properties and clinical efficacy when studied in either human saliva or laboratory test media.
Topics: Dental Stress Analysis; Elastomers; Humans; Materials Testing; Mechanical Phenomena; Orthodontic Appliances; Polyurethanes; Saliva; Tensile Strength; Time Factors
PubMed: 22906378
DOI: 10.1016/j.ortho.2012.06.013 -
The Cochrane Database of Systematic... Jul 2002The contraceptive vaginal sponge was developed as an alternative to the contraceptive diaphragm. The sponge, made of polyurethane impregnated with nonoxynol-9 (1g),... (Comparative Study)
Comparative Study Review
BACKGROUND
The contraceptive vaginal sponge was developed as an alternative to the contraceptive diaphragm. The sponge, made of polyurethane impregnated with nonoxynol-9 (1g), releases 125 mg of the spermicide over 24 hours of use. Unlike the diaphragm, the sponge can be used for more than one coital act within 24 hours without the insertion of additional spermicide, and the sponge does not require fitting or a prescription from a physician. How the sponge compares with the diaphragm in terms of efficacy and continuation is not clear.
OBJECTIVES
To compare the efficacy and continuation rates of the sponge with the diaphragm (used with nonoxynol-9). Our a priori hypothesis was that the sponge would have higher rates for failure and discontinuation than the diaphragm.
SEARCH METHODS
In April 2013, we searched the computerized databases MEDLINE, POPLINE, LILACS, CENTRAL, ClinicalTrials.gov and ICTRP.Earlier searches also included EMBASE. For the initial review, we searched the reference lists of relevant articles and book chapters.We also contacted investigators involved with the identified trials for other published or unpublished trials.
SELECTION CRITERIA
We included randomized controlled trials comparing the vaginal contraceptive sponge (Today; Collatex) with any diaphragm used with nonoxynol-9 to prevent pregnancy.
DATA COLLECTION AND ANALYSIS
We examined the studies identified through the literature searches for possible inclusion and evaluated their methodological quality using the Cochrane guidelines. We entered data into RevMan and calculated Peto odds ratios for overall pregnancy and 12-month discontinuation using numbers of women as the denominator. We also abstracted 12-month cumulative life-table ratios for these same outcomes but were unable to aggregate these data.
MAIN RESULTS
Two trials met the inclusion criteria. The sponge was significantly less effective in both trials in preventing overall pregnancy than was the diaphragm. In the larger USA trial, the 12-month cumulative life-table termination rates per 100 women for overall pregnancy were 17.4 for the sponge and 12.8 for the diaphragm. The rates were 24.5 for the sponge and 10.9 for the diaphragm in the UK trial.Similarly, discontinuation rates at 12 months were higher with the sponge than with the diaphragm (Odds ratio 1.31; 95% CI 1.07 to 1.59). Allergic-type reactions were more common with the sponge, although discontinuation for discomfort differed in the two trials.No new trials have been identified since the initial review.
AUTHORS' CONCLUSIONS
The sponge was less effective than the diaphragm in preventing pregnancy.Discontinuation rates were higher at 12 months as well.Other randomized controlled trials will be needed to resolve the potential role of spermicides in preventing sexually transmitted infections or in causing adverse effects
Topics: Contraceptive Devices, Female; Female; Humans; Nonoxynol; Pregnancy; Pregnancy Rate; Randomized Controlled Trials as Topic; Spermatocidal Agents
PubMed: 23866318
DOI: 10.1002/14651858.CD003172 -
Polymers Oct 2021Layered double hydroxides (LDHs) have attracted interest as reinforcing fillers in elastomers due to their ease of synthesis and customisability. A systematic review was... (Review)
Review
Layered double hydroxides (LDHs) have attracted interest as reinforcing fillers in elastomers due to their ease of synthesis and customisability. A systematic review was performed on the effect of LDHs on the mechanical properties of elastomers using the Scopus database. Of the 61 articles relevant to the search criteria, the majority were published on polyurethane (PU) and nitrile butadiene rubber (NBR). Mg-Al LDH was used in most of the studies and Zn-Al LDH was used second most common. LDH can act as a reinforcing filler, typically increasing tensile strength even at low concentrations, so it could be used as an alternative to traditional reinforcing fillers for elastomers. LDH can also be made a functional filler by selecting the right metals and interlayer anions. It was found that Mg-Al LDH and Zn-Al LDH can both participate in crosslinking reactions and can replace MgO and ZnO, respectively. Less Zn ions are required for crosslinking when LDH is used than when ZnO is used, making LDH more environmentally friendly. Organic modification is usually required to improve compatibility with the elastomer matrix, especially in non-polar elastomers. It enables exfoliation of the LDH and intercalation of polymer chains into the LDH interlayer to occur. Organic modifiers can also be used to functionalise the LDH. Stearic acid used in crosslinking systems can be replaced by stearate anions from stearate-modified LDH.
PubMed: 34771273
DOI: 10.3390/polym13213716