A novel mouse model of obstructive sleep apnea by bulking agent-induced tongue enlargement results in left ventricular contractile dysfunction.

AIMS: Obstructive sleep apnea (OSA) is a widespread disease with high global socio-economic impact. However, detailed pathomechanisms are still unclear, partly because current animal models of OSA do not simulate spontaneous airway obstruction. We tested whether polytetrafluoroethylene (PTFE) injection into the tongue induces spontaneous obstructive apneas. METHODS AND RESULTS: PTFE (100 µl) was injected into the tongue of 31 male C57BL/6 mice and 28 mice were used as control. Spontaneous apneas and inspiratory flow limitations were recorded by whole-body plethysmography and mRNA expression of the hypoxia marker KDM6A was quantified by qPCR. Left ventricular function was assessed by echocardiography and ventricular CaMKII expression was measured by Western blotting. After PTFE injection, mice showed features of OSA such as significantly increased tongue diameters that were associated with significantly and sustained increased frequencies of inspiratory flow limitations and apneas. Decreased KDM6A mRNA levels indicated chronic hypoxemia. 8 weeks after surgery, PTFE-treated mice showed a significantly reduced left ventricular ejection fraction. Moreover, the severity of diastolic dysfunction (measured as E/e') correlated significantly with the frequency of apneas. Accordingly, CaMKII expression was significantly increased in PTFE mice and correlated significantly with the frequency of apneas. CONCLUSIONS: We describe here the first mouse model of spontaneous inspiratory flow limitations, obstructive apneas, and hypoxia by tongue enlargement due to PTFE injection. These mice develop systolic and diastolic dysfunction and increased CaMKII expression. This mouse model offers great opportunities to investigate the effects of obstructive apneas.

Intensive care and anesthesia management for HARPOON beating heart mitral valve repair.

Patients with severe mitral valve regurgitation secondary to degenerative disease are known to benefit from mitral valve repair surgery. Novel techniques for achieving mitral valve repair on the beating heart have been developed and are being introduced into clinical practice. The HARPOON Beating Heart Mitral Valve Repair System (MVRS) in recent studies has demonstrated efficacy and safety for the repair of degenerative mitral valve disease on the beating heart. The device uses transoesophageal echocardiographic guidance to implant artificial expanded polytetrafluoroethylene (ePTFE) cords on prolapsed mitral valve leaflets in the beating heart. It requires general anaesthesia and there are specific intensive care and anaesthesia considerations for the safe management of these cases. This article describes the general principles of intensive care and anaesthesia management employed for the initial patients treated with the HARPOON Beating Heart MVRS, the outcomes for these patients, and the potential challenges for the future management of these cases.

Barrier agents for adhesion prevention after gynaecological surgery.

BACKGROUND: Pelvic adhesions can form secondary to inflammation, endometriosis, or surgical trauma. Strategies to reduce pelvic adhesion formation include placing barrier agents such as oxidised regenerated cellulose, polytetrafluoroethylene, and fibrin or collagen sheets between pelvic structures. OBJECTIVES: To evaluate the effects of barrier agents used during pelvic surgery on rates of pain, live birth, and postoperative adhesions in women of reproductive age. SEARCH METHODS: We searched the following databases in August 2019: the Cochrane Gynaecology and Fertility (CGF) Specialised Register of Controlled Trials, MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL), Epistemonikos, and trial registries. We searched reference lists of relevant papers, conference proceedings, and grey literature sources. We contacted pharmaceutical companies for information and handsearched relevant journals and conference abstracts. SELECTION CRITERIA: Randomised controlled trials (RCTs) on the use of barrier agents compared with other barrier agents, placebo, or no treatment for prevention of adhesions in women undergoing gynaecological surgery. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trials for eligibility and risk of bias and extracted data. We calculated odds ratios (ORs) or mean differences (MDs) with 95% confidence intervals (CIs) using a fixed-effect model. We assessed the overall quality of the evidence using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods. MAIN RESULTS: We included 19 RCTs (1316 women). Seven RCTs randomised women; the remainder randomised pelvic organs. Laparoscopy (eight RCTs) and laparotomy (11 RCTs) were the primary surgical techniques. Indications for surgery included myomectomy (seven RCTs), ovarian surgery (five RCTs), pelvic adhesions (five RCTs), endometriosis (one RCT), and mixed gynaecological surgery (one RCT). The sole indication for surgery in three of the RCTs was infertility. Thirteen RCTs reported commercial funding; the rest did not state their source of funding. No studies reported our primary outcomes of pelvic pain and live birth rate. Oxidised regenerated cellulose versus no treatment at laparoscopy or laparotomy (13 RCTs) At second-look laparoscopy, we are uncertain whether oxidised regenerated cellulose at laparoscopy reduced the incidence of de novo adhesions (OR 0.50, 95% CI 0.30 to 0.83, 3 RCTs, 360 participants; I² = 75%; very low-quality evidence) or of re-formed adhesions (OR 0.17, 95% CI 0.07 to 0.41, 3 RCTs, 100 participants; I² = 36%; very low-quality evidence). At second-look laparoscopy, we are uncertain whether oxidised regenerated cellulose affected the incidence of de novo adhesions after laparotomy (OR 0.72, 95% CI 0.42 to 1.25, 1 RCT, 271 participants; very low-quality evidence). However, the incidence of re-formed adhesions may have been reduced in the intervention group (OR 0.38, 95% CI 0.27 to 0.55, 6 RCTs, 554 participants; I² = 41%; low-quality evidence). No studies reported results on pelvic pain, live birth rate, adhesion score, or clinical pregnancy rate. Expanded polytetrafluoroethylene versus oxidised regenerated cellulose at gynaecological surgery (two RCTs) We are uncertain whether expanded polytetrafluoroethylene reduced the incidence of de novo adhesions at second-look laparoscopy (OR 0.93, 95% CI 0.26 to 3.41, 38 participants; very low-quality evidence). We are also uncertain whether expanded polytetrafluoroethylene resulted in a lower adhesion score (out of 11) (MD -3.79, 95% CI -5.12 to -2.46, 62 participants; very low-quality evidence) or a lower risk of re-formed adhesions (OR 0.13, 95% CI 0.02 to 0.80, 23 participants; very low-quality evidence) when compared with oxidised regenerated cellulose. No studies reported results regarding pelvic pain, live birth rate, or clinical pregnancy rate. Collagen membrane with polyethylene glycol and glycerol versus no treatment at gynaecological surgery (one RCT) Evidence suggests that collagen membrane with polyethylene glycol and glycerol may reduce the incidence of adhesions at second-look laparoscopy (OR 0.04, 95% CI 0.00 to 0.77, 47 participants; low-quality evidence). We are uncertain whether collagen membrane with polyethylene glycol and glycerol improved clinical pregnancy rate (OR 5.69, 95% CI 1.38 to 23.48, 39 participants; very low-quality evidence). One study reported adhesion scores but reported them as median scores rather than mean scores (median score 0.8 in the treatment group vs median score 1.2 in the control group) and therefore could not be included in the meta-analysis. The reported P value was 0.230, and no evidence suggests a difference between treatment and control groups. No studies reported results regarding pelvic pain or live birth rate. In total, 15 of the 19 RCTs included in this review reported adverse events. No events directly attributed to adhesion agents were reported. AUTHORS' CONCLUSIONS: We found no evidence on the effects of barrier agents used during pelvic surgery on pelvic pain or live birth rate in women of reproductive age because no trial reported these outcomes. It is difficult to draw credible conclusions due to lack of evidence and the low quality of included studies. Given this caveat, low-quality evidence suggests that collagen membrane with polyethylene glycol plus glycerol may be more effective than no treatment in reducing the incidence of adhesion formation following pelvic surgery. Low-quality evidence also shows that oxidised regenerated cellulose may reduce the incidence of re-formation of adhesions when compared with no treatment at laparotomy. It is not possible to draw conclusions on the relative effectiveness of these interventions due to lack of evidence. No adverse events directly attributed to the adhesion agents were reported. The quality of the evidence ranged from very low to moderate. Common limitations were imprecision and poor reporting of study methods. Most studies were commercially funded, and publication bias could not be ruled out.

Novel method for delayed primary closure and incisional hernia prevention in open abdomen: COmbined and MOdified Definitive Abdominal wall closure (COMODA).

BACKGROUND: Intended open abdomen is an option in cases of trauma and non-trauma patients. Nevertheless, after primary closure, incisional hernia rate is high. We describe a novel method, called COmbined and MOdified Definitive Abdominal closure (COMODA), a delayed primary closure which prevents incisional hernia. METHODS: A negative pressure wound therapy system is combined with a condensed polytetrafluoroethylene (cPTFE) mesh. TRIAL REGISTRATION: ISRCTN72678033. RESULTS: Ten male patients with a median age of 68.8 (43-87) years were included. Primary closure rate was 100% per protocol. The median number of procedures per patient was 5.7 (5-9). Primary closure was obtained in 20.8 (10-32) days and median hospital stay was 36.3 (18-52) days. Only one patient developed incisional hernia during a median follow-up of 27 (8-60) months. CONCLUSION: COMODA method allows for a high rate of delayed primary closure. It is safe and decreases the risk for developing an incisional hernia. However, a large number of patients are needed to support this conclusion.

A simple coating method of PDMS microchip with PTFE for synthesis of dexamethasone-encapsulated PLGA nanoparticles.

Dexamethasone is a widely used drug in medical and biological applications. Since the systematic and controllable release of this drug is of significant importance, encapsulation of this anti-inflammatory drug in poly(lactic-co-glycolic acid) (PLGA) nanoparticles can minimize uncontrolled issues. As dexamethasone-encapsulated PLGA nanoparticles are synthesized in the presence of organic solvents, poly(dimethylsiloxane) (PDMS)-based microchannels collapse due to the swelling problem. In present study, PTFE nanoparticles were used for the surface modification of the microchannels to prevent absorption and adhesion of solvents into the microchannels' wall. The contact angle analysis of microchips after coating showed that the surface of microchannels bear the superhydrophobicity feature (140.30°) and SEM images revealed that PTFE covered the surface of PDMS, favorably. Then, the prepared microchip was tested for the synthesis of dexamethasone-loaded nanoparticles. SEM and atomic force microscopy (AFM) images of the synthesized nanoparticles represented that there was not any evidence of adhesion or absorption of nanoparticles. Furthermore, the monodispersity of nanoparticles was discernible. As AFM results revealed, the average diameters of 47, 63, and 82 nm were achieved for flow ratios of 0.01, 0.05, and 0.1, respectively. To evaluate the drug efficiency, cumulative release and encapsulation efficiency were analyzed which showed much more efficiency than the synthesized nanoparticles in the bulk mode. In addition, MTT test revealed that nanoparticles could be considered as a non-toxic material. Since the synthesis of drug-loaded nanoparticles is ubiquitous in laboratory experiments, the approach presented in this study can render more versatility in this regard.

Repositioning Technique for the Decompression of Symptomatic Dolichoectatic Vertebrobasilar Pathology: A Comprehensive Review of Sling Characteristics and Surgical Experience.

OBJECTIVE: The repositioning of a dolichoectatic vertebrobasilar artery (VBA) for arterial decompression has been extensively used in the clinical setting. We aimed to describe and summarize the technical characteristics and clinical results of the sling technique. METHODS: The terms "dolichoectatic aneurysm," "dolichoectasia," "ectasia," and "megadolichoectasia" were used to search for pertinent reports related to the VBA territory. Studies related to the "decompression," "repositioning," "transposition," "anchoring," "pexy," and "sling" techniques were screened, collected, and summarized by 1 of us (L.W.). RESULTS: We identified 20 pertinent reports involving 59 cases. The sling repositioning techniques were divided into the following 4 subtypes: suture-lasso, vasculopexy, clip-lasso, and wrap-sling. Overall, 35 of the 59 patients (59.3%) were treated using the wrap-sling technique. Among these cases, Gore-Tex grafts were the most common sling material used. Of the cases with reported postoperative characteristics, all the patients except for 1 had experienced complete or significant remission of symptoms. Although 11 of the 59 patients (18.6%) had developed complications, the rate of adverse effects had decreased to 3.6% (2 of 55) during the long-term follow-up period (mean, 40.4 months; range, 2.1-168), and the outcomes were unremarkable in 54 of the 55 patients (98.2%). CONCLUSIONS: The excellent surgical outcomes and durable long-term results suggest that the repositioning technique is highly effective in resolving symptoms related to the compression of DVB pathology. The wrap-sling technique might be the preferred option owing to the simultaneous symptom relief and lower rate of temporary complications. However, cranial nerve manipulation should be meticulously implemented to avoid permanent negative effects.

Drug-delivering nerve conduit improves regeneration in a critical-sized gap.

Autologous nerve grafts are the current "gold standard" for repairing large nerve gaps. However, they cause morbidity at the donor nerve site and only a limited amount of nerve can be harvested. Nerve conduits are a promising alternative to autografts and can act as guidance cues for the regenerating axons, without the need to harvest donor nerve. Separately, it has been shown that localized delivery of GDNF can enhance axon growth and motor recovery. FK506, an FDA approved small molecule, has also been shown to enhance peripheral nerve regeneration. This paper describes the design of a novel hole-based drug delivery apparatus integrated with a polytetrafluoroethylene (PTFE) nerve conduit for controlled local delivery of a protein such as GDNF or a small molecule such as FK506. The PTFE devices were tested in a diffusion chamber, and the bioactivity of the released media was evaluated by measuring neurite growth of dorsal root ganglions (DRGs) exposed to the released drugs. The drug delivering nerve guide was able to release bioactive concentrations of FK506 or GDNF. Following these tests, optimized drug releasing nerve conduits were implanted across 10 mm sciatic nerve gaps in a BL6 yellow fluorescent protein (YFP) mouse model, where they demonstrated significant improvement in muscle mass, compound muscle action potential, and axon myelination in vivo as compared with nerve conduits without the drug. The drug delivery nerve guide could release drug for extended periods of time and enhance axon growth in vitro and in vivo.

Heparin-Coated Grafts Reduce Mortality in Pediatric Patients Receiving Systemic-to-Pulmonary Shunts.

We aimed to evaluate the outcomes of systemic-to-pulmonary (SP) shunt procedures utilizing heparin-coated (HC) polytetrafluoroethylene (PTFE) vascular grafts compared to uncoated (non-HC) grafts, in order to observe any benefits in pediatric patients. Our institution switched from using non-HC grafts to HC grafts in March 2011. We conducted a retrospective review of consecutive pediatric patients receiving SP shunts from May 2008 to December 2015. Perioperative variables including baseline characteristics, morbidity, mortality, and blood product utilization were evaluated between the HC and non-HC groups. A total of 142 pediatric patients received SP shunts during the study period: 69 patients received HC shunts and 73 patients received non-HC shunts. The HC group had significantly fewer desaturation or arrest events (P < 0.01), fewer shunt occlusions/thromboses (P < 0.01). There was no statistically significant difference in unplanned reoperations between groups (P = 0.18). The HC group demonstrated significantly lower overall 30-day mortality (P < 0.01), as well as shunt-related mortality (P < 0.01). The HC group had significantly lower postoperative packed red blood cell utilization as compared to the non-HC group (P < 0.01). In this study, pediatric patients receiving HC PTFE grafts in SP shunts demonstrated significantly lower shunt-related mortality. The majority of HC grafts remained patent. These findings suggest that HC grafts used in SP shunt procedures may benefit pediatric patients in terms of efficacy and outcomes.

Urethral injection therapy for urinary incontinence in women.

BACKGROUND: Urinary incontinence imposes a significant health and economic burden to society. Periurethral or transurethral injection of bulking agents is a minimally invasive surgical procedure used as one the surgical treatments of stress urinary incontinence (SUI) in adult women. OBJECTIVES: To assess the effects of periurethral or transurethral injection therapy on the cure or improvement of urinary incontinence in women. SEARCH METHODS: We searched the Cochrane Incontinence Group Specialised Trials Register (searched 8 November 2010) and the reference lists of relevant articles. SELECTION CRITERIA: All randomised or quasi-randomised controlled trials of treatment for urinary incontinence in which at least one management arm involved periurethral or transurethral injection therapy. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed methodological quality of each study using explicit criteria. Data extraction was undertaken independently and clarification concerning possible unreported data sought directly from the investigators. MAIN RESULTS: Excluding duplicate reports, we identified 14 trials (excluding one that was subsequently withdrawn from publication and not included in this analysis) including 2004 women that met the inclusion criteria. The limited data available were not suitable for meta-analysis because they all came from separate trials. Trials were small and generally of moderate quality.One trial of 45 women that compared injection therapy with conservative treatment showed early benefit for the injectable therapy with respect to continence grade (risk ratio (RR) 0.70, 95% confidence interval (CI) 0.52 to 0.94) and quality of life (mean difference (MD) 0.54, 95% CI 0.16 to 0.92). Another trial, comparing Injection of autologous fat with placebo, terminated early because of safety concerns. Two trials that compared injection with surgical management found significantly better objective cure in the surgical group (RR 4.77, 95% CI 1.96 to 11.64; and RR 1.69, 95% CI 1.02 to 2.79), although the latter trial data did not reach statistical significance if an intention-to-treat analysis was used.Eight trials compared different agents and all results had wide confidence intervals. Silicone particles, calcium hydroxylapatite, ethylene vinyl alcohol, carbon spheres and dextranomer hyaluronic acid combination gave improvements which were not shown to be more or less efficacious than collagen. Dextranomer hyaluronic acid compound treated patients appeared to have significantly higher rates of injection site complications (16% with the hyaluronic acid compound versus none with collagen; RR 37.78, 95% CI 2.34 to 610.12) and this product has now been withdrawn from the market.A comparison of periurethral and transurethral methods of injection found similar outcomes but a higher (though not statistically significant) rate of early complications in the periurethral group. One trial of 30 women showed a weak (but not clinically significant) advantage for patient satisfaction (data not suitable for analysis in RevMan) after mid-urethral injection in comparison to bladder neck injection but with no demonstrable difference in continence levels. AUTHORS' CONCLUSIONS: The available evidence base remains insufficient to guide practice. In addition, the finding that placebo saline injection was followed by a similar symptomatic improvement to bulking agent injection raises questions about the mechanism of any beneficial effects. One small trial comparing silicone particles with pelvic floor muscle training was suggestive of benefit at three months but it is not known if this was sustained, and the treatment was associated with high levels of postoperative retention and dysuria. Greater symptomatic improvement was observed with surgical treatments, though the advantages need to be set against likely higher risks. No clear-cut conclusions could be drawn from trials comparing alternative agents, although dextranomer hyaluronic acid was associated with more local side effects and is no longer commercially available for this indication. There is insufficient evidence to show superiority of mid-urethral or bladder neck injection. The single trial of autologous fat provides a reminder that periurethral injections can occasionally cause serious side effects. Also, a Brief Economic Commentary (BEC) identified three studies suggesting that urethral bulking agent might be more cost-effective compared with retropubic mid-urethral slings, transobturator or traditional sling procedure when used as an initial treatment in women without hypermobility or as a follow-up to surgery failure provided injection is kept minimal. However, urethral bulking agent might not be cost-effective when compared with traditional sling as an initial treatment of SUI when a patient is followed up for a longer period (15 months post-surgery).

Endoscopic injection therapy.

Since the U.S. Food and Drug Administration approved dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of vesicoureteral reflux, endoscopic injection therapy using Deflux has become a popular alternative to open surgery and continuous antibiotic prophylaxis. Endoscopic correction with Deflux is minimally invasive, well tolerated, and provides cure rates approaching those of open surgery (i.e., approximately 80% in several studies). However, in recent years a less stringent approach to evaluating urinary tract infections (UTIs) and concerns about long-term efficacy and complications associated with endoscopic injection have limited the use of this therapy. In addition, there is little evidence supporting the efficacy of endoscopic injection therapy in preventing UTIs and vesicoureteral reflux-related renal scarring. In this report, we reviewed the current literature regarding endoscopic injection therapy and provided an updated overview of this topic.

Management of radial artery perforation during transradial catheterization using a polytetrafluoroethylene-covered coronary stent.

An 88-year-old woman underwent attempted percutaneous coronary intervention (PCI) through a right radial approach. Catheterization was complicated by radial artery perforation. Conservative therapeutic options including external compression, advancement of a diagnostic catheter distal to the perforation, and balloon tamponade failed to control the bleeding requiring deployment of a Polytetrafluoroethylene (PTFE)-covered stent to seal the perforation. We describe the stepwise approach advocated for managing a radial perforation and summarize relevant literature available for the same.

Teflon Injection into the Trachea Causes Predictable Fibroblastic Response and Collagen Deposition: A Pilot Study.

BACKGROUND: Expiratory central airway collapse is an increasingly recognized abnormality of the central airways and may be present in as many as 22% of patients evaluated for chronic obstructive pulmonary disease and/or asthma. Many current treatment options require invasive procedures that have been shown to cause significant morbidity and mortality. To test the hypothesis that Teflon injection will induce sufficient fibroblast proliferation and collagen deposition, we evaluated the time course on the effect of Teflon injection in the posterior membranous trachea on the histopathology of the tracheobronchial tree. METHODS: Six Yucatan Pigs were assigned to undergo general anesthesia and injection of 0.3 to 0.5 mL of sterile Teflon paste in 50% glycerin into the posterior membranous tracheal wall. A control pig received an equivalent volume of glycerin. Animals were euthanized in predefined intervals and tracheas were excised and examined under light microscopy for identifying fibroblast proliferation and collagen deposition. RESULTS: Compared with the control pig, the Teflon injection site showed tissue reaction of fibrohistiocytic proliferation and subsequent collagen deposition in all animals. Furthermore, the increased fibroblast proliferation and collagen deposition were time dependent (P<0.01). CONCLUSION: This pilot study demonstrates histopathologic changes in the trachea after Teflon injection, comprised of increased fibroblast activity and collagen deposition that could be of potential use in creating greater airway rigidity in patients with sever diffuse excessive dynamic airway collapse.

[Effects of microporous polysaccharide on foreign body reaction induced by subcutaneously imbedding expanded polytetrafluoroethylene in mice].

Objective: To observe the effects of early applying of microporous polysaccharide on foreign body reaction induced by subcutaneously imbedding expanded polytetrafluoroethylene (e-PTFE) in mice. Methods: Ten wide type adult C57BL/6J mice were collected and made a full-thickness skin incision on both sides of their back. The two incisions on the back of each mouse were divided into two groups according the random number table, with 10 incisions in each group. A tube-shaped e-PTFE was imbedded into each incision in microporous polysaccharide group, and then 0.03 g microporous polysaccharide was evenly sprayed in the cavity. Whereas, a tube-shaped e-PTFE was imbedded into each incision in control group without other treatment. The incisions in two groups were performed with conventional full-thickness suture. On post operation day (POD) 14, the e-PTFE surrounded with fibrous capsule in each incision of two groups was taken out, and then fibrous capsule tissue was harvested. The thickness of fibrous capsule was observed and measured with HE staining. Collagen fiber distribution in fibrous capsule tissue was observed with Masson staining to calculate the collagen fiber index. Neovascularization and macrophage infiltration in fibrous capsule tissue were observed respectively with immunohistochemical staining, and the numbers of new vessels and macrophages were counted. Data were processed with t test. Results: On POD 14, the thickness of fibrous capsule surrounding e-PTFE imbedded into the incision of microporous polysaccharide group was (127±19) µm, which was significantly thinner than that of control group [(250±35) µm, t=4.13, P<0.05]. On POD 14, the collagen fiber index of fibrous capsule tissue surrounding e-PTFE imbedded into the incision of microporous polysaccharide group was 0.500±0.003, which was significantly higher than that of control group (0.488±0.004, t=5.00, P<0.05). On POD 14, the number of new vessels in fibrous capsule tissue surrounding e-PTFE imbedded into the incision of microporous polysaccharide group was 19±3 per 400 fold visual field, which was significantly more than that of control group (11±3 per 400 fold visual field, t=2.05, P<0.05). On POD 14, the number of macrophages in fibrous capsule tissue surrounding e-PTFE imbedded into the incision of microporous polysaccharide group was 64±5 per 400 fold visual field, which was close to that of control group (66±7 per 400 fold visual field, t=0.78, P>0.05). Conclusions: Topically applying microporous polysaccharide can reduce the formation of fibrous capsule after subcutaneous imbedding of e-PTFE in mice, and it can improve the collagen deposition and angiogenesis but not impact on macrophage infiltration.

STING versus HIT technique of endoscopic treatment for vesicoureteral reflux: A systematic review and meta-analysis.

AIM: Our study aimed to compare the efficacy of two endoscopic techniques used for the correction of vesicoureteral reflux (VUR): subureteral transurethral injection (STING) and hydrodistension implantation technique (HIT). METHODS: A systematic review was conducted using MEDLINE, Google scholar, and Cochrane databases from 1984 to 2015. Meta-analysis of the selected studies was performed to compare the extent of reflux resolution following both techniques. RESULTS: Six observational studies met the inclusion criteria for content. These comprised 632 ureters treated by STING and 895 ureters treated by HIT procedure. All included studies utilized dextranomer/hyaluronic acid (Deflux) as the bulking agent. The overall resolution of VUR was significantly higher in HIT (82.5%) compared to STING (71.4%) [pooled odds ratio (OR)=0.54; 95% confidence interval (CI) 0.42-0.69; P<0.0001; I2=8%]. A subgroup analysis showed that HIT had better outcomes than STING for both lower grade (I-III) [OR=0.43; 95% CI 0.23-0.82; P=0.01; I2=0%] and high-grade VUR (IV-V) [OR=0.43; 95% CI 0.20-0.91; P=0.03; I2=0%]. However, there was no statistical difference in the requirement of additional injections between STING and HIT groups. CONCLUSION: HIT is superior to STING technique for resolution of VUR after Deflux injection. However, more randomized trials with longer follow-up are necessary to demonstrate the benefit of HIT compared to STING procedure. LEVEL OF EVIDENCE: Retrospective comparative studies - level III.

Polytetrafluoroethylene Ingestion as a Way to Increase Food Volume and Hence Satiety Without Increasing Calorie Content.

Since satiety is largely due to stretch of the stomach and people tend to eat a consistent weight of food, increasing food volume and mass increases satiety. This can be achieved without increasing the calories of food by mixing food with a material that cannot be metabolized. Such a material should be inert, safe, resistant to stomach acid, lack taste, available in powder form, smooth, resistant to heat, and cost effective. Polytetrafluoroethylene (PTFE) is an ideal substance for this purpose. It is a soft plastic that is widely considered to be the most inert material known and is extremely stable. Animal feeding trials showed that rats fed a diet of 25% PTFE for 90 days had no signs of toxicity and that the rats lost weight. This article publishes the data from these subchronic animal feeding trials, reviews the relevant available literature, and hypothesizes that increasing the volume of food by mixing the food with PTFE powder at a ratio of 3 parts food to 1 part PTFE by volume will substantially improve satiety and reduce caloric consumption in people.

Antibiofilm Activity of Low-Amperage Continuous and Intermittent Direct Electrical Current.

Bacterial biofilms are difficult to treat using available antimicrobial agents, so new antibiofilm strategies are needed. We previously showed that 20, 200, and 2,000 µA of electrical current reduced bacterial biofilms of Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. Here, we tested continuous direct current at lower amperages, intermittent direct current, and combinations of surface materials (Teflon or titanium) and electrode compositions (stainless steel, graphite, titanium, or platinum) against S. aureus, S. epidermidis, and P. aeruginosa biofilms. In addition, we tested 200 or 2,000 µA for 1 and 4 days against biofilms of 33 strains representing 13 species of microorganisms. The logarithmic reduction factor was used to measure treatment effects. Using continuous current delivery, the lowest active amperage was 2 µA for 1, 4, or 7 days against P. aeruginosa and 5 µA for 7 days against S. epidermidis and S. aureus biofilms. Delivery of 200 µA for 4 h a day over 4 days reduced P. aeruginosa, S. aureus, and S. epidermidis biofilms on Teflon or titanium discs. A reduction of P. aeruginosa, S. aureus, and S. epidermidis biofilms was measured for 23 of 24 combinations of surface materials and electrode compositions tested. Four days of direct current delivery reduced biofilms of 25 of 33 strains studied. In conclusion, low-amperage current or 4 h a day of intermittent current delivered using a variety of electrode compositions reduced P. aeruginosa, S. aureus, and S. epidermidis biofilms on a variety of surface materials. The electricidal effect was observed against a majority of bacterial species studied.

Barrier agents for adhesion prevention after gynaecological surgery.

BACKGROUND: Pelvic adhesions can form as a result of inflammation, endometriosis or surgical trauma. During pelvic surgery, strategies to reduce pelvic adhesion formation include placing barrier agents such as oxidised regenerated cellulose, polytetrafluoroethylene or fibrin sheets between the pelvic structures. OBJECTIVES: To evaluate the effects of barrier agents used during pelvic surgery on rates of pain, live birth and postoperative adhesions in women of reproductive age. SEARCH METHODS: We searched the following databases in February 2015: the Menstrual Disorders and Subfertility Group (MDSG) Specialised Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL) and trial registries. We handsearched relevant journals, conference proceedings and grey literature sources and we contacted pharmaceutical companies for information. SELECTION CRITERIA: Randomised controlled trials (RCTs) of the use of barrier agents compared with other barrier agents, placebo or no treatment for the prevention of adhesions in women undergoing gynaecological surgery. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for eligibility and risk of bias and extracted the data. We calculated odds ratios (ORs) or mean differences (MD) with 95% confidence intervals (CIs) using a fixed effect model. The overall quality of the evidence was assessed using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods. MAIN RESULTS: Eighteen RCTs (1262 women) were included. Six RCTs randomised women; the remainder randomised pelvic organs. Laparoscopy (eight RCTs) and laparotomy (10 RCTs) were the primary surgical techniques. Indications for surgery included myomectomy (six RCTs), ovarian surgery (five RCTs), pelvic adhesions (five RCTs), endometriosis (one RCT) and mixed (one RCT). The sole indication for surgery in three of the RCTs was infertility. Twelve RCTs reported commercial funding; the rest did not state their source of funding.No studies reported either of our primary outcomes of pelvic pain and live birth. Oxidised regenerated cellulose (Interceed) versus no treatment at laparoscopy or laparotomy (13 RCTs)At second-look laparoscopy oxidised regenerated cellulose at laparoscopy was associated with reduced incidence of de novo adhesions (OR 0.50, 95% CI 0.30 to 0.83, three RCTs, 360 participants, I(2) = 75%, very low-quality evidence) and of re-formed adhesions (OR 0.17, 95% CI 0.07 to 0.41, three RCTs, 100 participants, I(2) = 36%, low quality evidence).At second-look laparoscopy no evidence was found of any difference between the groups in the incidence of de novo adhesions after laparotomy (OR 0.72, 95% CI 0.42 to 1.25, one RCT, 271 participants, I(2) = 41%, low-quality evidence). However, the incidence of re-formed adhesions was lower in the intervention group (OR 0.38, 95% CI 0.27 to 0.55, six RCTs, 554 participants, moderate-quality evidence). Expanded polytetrafluoroethylene (Gore-Tex) versus no treatment at gynaecological surgery (one RCT) The evidence suggested that at second-look laparoscopy expanded polytetrafluoroethylene was associated with a reduction in new adhesion formation (OR 0.17, 95% CI 0.03 to 0.94, one RCT, 42 participants, low-quality evidence). Expanded polytetrafluoroethylene (Gore-Tex) versus oxidised regenerated cellulose (Interceed) at gynaecological surgery (two RCTs)One RCT found no difference between the groups at second-look laparoscopy in the incidence of de novo adhesions (OR 0.93, 95% CI 0.26 to 3.41, 38 participants, very low-quality evidence). A second RCT suggested that the expanded polytetrafluoroethylene group had a lower adhesion score (out of 11) (MD -3.79, 95% CI -5.12 to -2.46, 62 participants, very low-quality evidence) and a lower risk of re-formed adhesions (OR 0.13, 95% CI 0.02 to 0.80, 23 participants, very low-quality evidence). This last finding was sensitive to choice of effect estimate and no longer suggested a difference between the groups when a risk ratio was calculated (RR 0.36, 95% CI 0.13 to 1.01). Sodium hyaluronate and carboxymethylcellulose (Seprafilm) versus no treatment at gynaecological surgery (one RCT)Sodium hyaluronate and carboxymethylcellulose was associated with a lower adhesion score (out of 4) at second-look laparoscopy (MD 0.49, 95% CI 0.53 to 0.45, one RCT, 127 participants, moderate-quality evidence). Fibrin sheet versus no treatment at laparoscopic myomectomy (one RCT)There was no evidence of a difference between the groups in the incidence of de novo adhesions at second-look laparoscopy (OR 1.20, 95% CI 0.42 to 3.41, one RCT, 62 participants) or in adhesion score (out of 4) (MD 0.14, 95% CI -0.67 to 0.39, one RCT, 48 participants, low-quality evidence).Fourteen of the 18 RCTs reported adverse events. No events directly attributed to adhesion agents were reported. AUTHORS' CONCLUSIONS: We found no evidence on the effects of barrier agents used during pelvic surgery on either pain or fertility outcomes in women of reproductive age.Low quality evidence suggests that oxidised regenerated cellulose (Interceed), expanded polytetrafluoroethylene (Gore-Tex) and sodium hyaluronate with carboxymethylcellulose (Seprafilm) may all be more effective than no treatment in reducing the incidence of adhesion formation following pelvic surgery. There is no conclusive evidence on the relative effectiveness of these interventions. There is no evidence to suggest that fibrin sheet is more effective than no treatment. No adverse events directly attributed to the adhesion agents were reported. The quality of the evidence ranged from very low to moderate. The most common limitations were imprecision and poor reporting of study methods. Most studies were commercially funded, and publication bias could not be ruled out.

Impact of pericardium bovine patch (Tutomesh(®)) on incisional hernia treatment in contaminated or potentially contaminated fields: retrospective comparative study.

PURPOSE: This retrospective comparative study analyzes the outcome of patients affected by incisional hernia in potentially contaminated or contaminated field, treated by three operative techniques. METHODS: 152 patients (62 M:90 F; mean age 65 ± 14 years) underwent incisional hernia repair (January 2002-January 2012) in complicated settings. Criteria of inclusion in the study were represented by the following causes of admission: mesh rejection/infection, obstruction without gangrene but with possible peritoneal bacterial translocation, obstruction with gangrene, enterocutaneous fistula or simultaneous presence of ileo- or colostomy. The patients were divided into three groups: A (n = 76), treated with primary closure technique; B and C (n = 38 each), with reinforcement by synthetic or pericardium bovine mesh (Tutomesh(®)), respectively. The prosthetic groups were divided into Onlay and Sublay subgroups. RESULTS: Significant decreases in C vs A were observed for wound infection (3 vs 37%) and recurrence (0 vs 14%), and in C vs B for wound infection (3 vs 53%), seroma (0 vs 34%) and recurrence (0 vs 16%). Patients with concomitant bowel resection (BR) (43%) showed (all P < 0.05) an increase of overall morbidity (55 vs 33%) and wound infection rate (42 vs 24%) compared to cases without BR. Morbidity presented no significant differences in C-Onlay or Sublay subgroups. B-Sublay subgroup has (all P < 0.05) lower overall morbidity (20 vs 75%), wound infection (10 vs 68%) and seroma (0 vs 46%) than B-Onlay. CONCLUSIONS: The pericardium bovine patch seems to be safe and effective to successfully repair ventral hernia in potentially contaminated operative fields, especially in association with bowel resection.

Small airway-centered granulomatosis caused by long-term exposure to polytetrafluoroethylene.

To date, there have been no reports of chronic pulmonary granulomatosis associated with exposure to polytetrafluoroethylene (PTFE). Here, we report three cases of small airway-centered granulomatous lesions in workers employed at facilities that apply coatings to pans and other utensils. The workers were repeatedly exposed to PTFE particles that were probably generated by the drying process when PTFE coatings are dried in a convection oven at high temperatures (380-420 °C). The duration of inhalational PTFE exposure was between 7 and 20 years. We found granulomatous lung lesions around the small airways in lung biopsy specimens obtained from the workers. Scanning electron microscopy/energy-dispersive x-ray spectroscopy analysis was performed focusing on areas where the PTFE particles were suspected to be located in macrophages. The scanning electron microscopy/energy-dispersive x-ray spectroscopy analyses revealed fluorine in the particles. Lung tissue samples from all cases were analyzed using a fully automated Fourier transform infrared spectrometer. Analysis of the spectrum extracted from the position of the foreign particles enabled precise identification of the foreign bodies as PTFE. Fourier transform infrared revealed that all of the lung tissue samples had bands at 1,202 to 1,148 cm(-1) and 1,202 to 1,146 cm(-1), which are characteristic of the asymmetric and symmetric stretching vibrations of the C-F bonds of PTFE. These cases suggest that recurrent inhalational exposure to PTFE particles causes chronic pulmonary granulomatosis.

Types of urethral catheter for reducing symptomatic urinary tract infections in hospitalised adults requiring short-term catheterisation: multicentre randomised controlled trial and economic evaluation of antimicrobial- and antiseptic-impregnated urethral catheters (the CATHETER trial).

BACKGROUND: Catheter-associated urinary tract infection (CAUTI) is a major preventable cause of harm for patients in hospital and incurs significant costs for health-care providers such as the UK NHS. Many preventative strategies and measures have been introduced to minimise CAUTI risk, including the use of antimicrobial catheters. However, there is considerable uncertainty regarding their usefulness in terms of reducing symptomatic CAUTI, and whether or not they are cost-effective. OBJECTIVES: Do antimicrobial catheters reduce the rate of symptomatic urinary tract infection (UTI) during short-term hospital use and is their use cost-effective for the UK NHS? DESIGN: A pragmatic multicentre UK randomised controlled trial comparing three catheters as they would be used in the UK NHS: antimicrobial-impregnated (nitrofurazone) and antiseptic-coated (silver alloy) catheters with the standard polytetrafluoroethylene (PTFE)-coated catheters. Economic evaluation used a decision model populated with data from the trial. Sensitivity analysis was used to explore uncertainty. SETTING: Relevant clinical departments in 24 NHS hospitals throughout the UK. PARTICIPANTS: Adults requiring temporary urethral catheterisation for a period of between 1 and 14 days as part of their care, predominantly as a result of elective surgery. INTERVENTIONS: Eligible participants were randomised 1 : 1 : 1 to one of three types of urethral catheter in order to make the following pragmatic comparisons: nitrofurazone-impregnated silicone catheter compared with standard PTFE-coated latex catheter; and silver alloy-coated hydrogel latex catheter compared with standard PTFE-coated latex catheter. MAIN OUTCOME MEASURES: The primary outcome for clinical effectiveness was the incidence of UTI at any time up to 6 weeks post randomisation. This was defined as any symptom reported during catheterisation, up to 3 days or 1 or 2 weeks post catheter removal or 6 weeks post randomisation combined with a prescription of antibiotics, at any of these times, for presumed symptomatic UTI. The primary economic outcome was incremental cost per quality-adjusted life-year (QALY). Health-care costs were estimated from NHS sources with QALYs calculated from participant completion of the European Quality of Life-5 Dimensions (EQ-5D). RESULTS: Outcome analyses encompassed 6394 (90%) of 7102 participants randomised. The rate of symptomatic UTI within 6 weeks of randomisation was 10.6% in the nitrofurazone group (n = 2153; -2.1% absolute risk difference), 12.5% in the silver alloy group (n = 2097; -0.1% absolute risk difference) and 12.6% in the PTFE group (n = 2144). The effect size {odds ratio (OR) [97.5% confidence interval (CI)]} was 0.82 (97.5% CI 0.66 to 1.01) for nitrofurazone (p = 0.037) and 0.99 (97.5% CI 0.81 to 1.22) for silver alloy (p = 0.92) catheters. The nitrofurazone catheters were more likely to cause discomfort during use and on removal. The primary economic analysis suggested that nitrofurazone-impregnated catheters would be, on average, the least costly (> £7 less than PTFE) and most effective option at current NHS prices. There was a 73% chance that nitrofurazone would be cost saving and an 84% chance that the incremental cost per QALY would be < £30,000. At the trial price (£6.46), silver alloy catheters were very unlikely to be cost-effective. These results were unchanged in sensitivity analyses, although when the length of stay cost was excluded the incremental cost per QALY for nitrofurazone against PTFE was £28,602. CONCLUSIONS: The trial estimate of clinical effectiveness for nitrofurazone-impregnated catheters was less than the pre-specified minimum absolute risk difference that we considered important (-3.3%), and the surrounding CI included zero, indicating that any reduction in catheter-associated UTI was uncertain. Economic analysis, although associated with uncertainty, suggested that nitrofurazone-impregnated catheters may be cost-effective for the NHS. The trial ruled out the possibility that silver alloy-coated catheters might reach the pre-set degree of clinical effectiveness and that their use was unlikely to be cost-effective. These findings should be considered by patients, clinicians and health-care policy-makers to determine whether or not a change in practice is worthwhile. Future research should be aimed at determining the minimum clinically important difference in terms of CAUTI prevention in comparative trials, and to identify reliable methods which can detect the impact of the intervention on quality of life and other drivers of cost, when the intervention is a subsidiary part of overall treatment plans.