durability
Dotaz
Zobrazit nápovědu
INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is one of the most significant inventions in cardiology, as it provides a viable minimally invasive treatment option for patients with aortic stenosis, the most common valvular disease in the developed world and one with a poor prognosis when left untreated. Using data available to date, this review aims to discuss and identify possible predictors of TAVI valve durability - an essential requirement for the device's wide-spread use, especially in younger patients. AREAS COVERED: This article explores the main causes of bioprosthetic valve dysfunction (BVD) based on pathophysiology and available data, and reviews possible predictors of BVD including prosthesis-related, procedure-related, and patient-related factors. An emphasis is made on affectable predictors, which could potentially be targeted with prevention management and improve valve durability. A literature search of online medical databases was conducted using relevant key words and dates; significant clinical trials were identified. A brief overview of important randomized controlled trials with mid to long-term follow-up is included in this article. EXPERT OPINION: Identifying modifiable predictors of valve dysfunction presents an opportunity to enhance and predict valve durability - a necessity as patients with longer life-expectancies are being considered for the procedure.
- MeSH
- aortální chlopeň chirurgie MeSH
- aortální stenóza * chirurgie MeSH
- bioprotézy * MeSH
- lidé MeSH
- selhání protézy MeSH
- srdeční chlopně umělé * MeSH
- transkatetrální implantace aortální chlopně * škodlivé účinky metody MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Fazetované korunky již několik desítek let patří ke standardnímu typu ošetření ve fixní protetice. Fazetovací materiály svými vlastnostmi významně ovlivňují stabilitu ošetření. Cílem této studie bylo posoudit změny na okluzních ploškách, kvalitu krčkového uzávěru, stálost tvaru i barvy fazety a stav gingivy. Na souboru 102 kovových korunek fazetovaných keramikou a plastem byl porovnán výchozí stav a změny po dvou letech ve funkci. Autoři použili kritéria United States Public Health Service System a výsledky statisticky zhodnotili. Po dvou letech bylo shledáno 94 % kovokeramických korunek a 98 % fazetovaných plastem klinicky intaktních. U tří fazet z keramiky a u jedné z kompozitního plastu byla nalezena prasklina. Signifikantní rozdíly u obou typů materiálů byly vyhodnoceny ve změně polohy krčkového uzávěru a statisticky významně se zhoršil i stav gingivy. Změna barvy byla popsána u fazet z kompozitního plastu, keramická fazeta se nezměnila ani tvarově, ani barevně.
Veneer crowns have represented a standardway of treatment in fixed prosthetics for several decades. Veneer materials' properties significantly influence the stability of the crown. The aim of this study was to evaluate possible changes of occlusal surfaces, quality of the crown margin, stability of the veneer shape and colour and the gingival status. A group of 102 metal crowns with both ceramic and plastic veneers was evaluated. The initial state of the crowns and changes after the two years of use were compared.The authors have used the United States Public Health Service System criteria, the results were processed statistically. After two years of function, 94 % of metal-ceramic crowns and 98 % of metal-polymer crowns were clinically intact.The crack has been found in three ceramic veneers and in one composite veneer. Significant differences between these two materials were found regarding the changes of crown margin and the gingival status.The colour changes have been detected in the composite veneers; the ceramic veneers have changed neither in shape nor in colour.
- MeSH
- slitiny chemie MeSH
- stenty * MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Transcatheter aortic valve implantation (TAVI) is a widely used intervention in patients who are at high risk or contraindicated for cardiac surgery. The procedure is technically feasible in most patients and has very good mid-term clinical outcomes. In this special report, we evaluated the long-term outcome after TAVI and durability of percutaneously implanted aortic valve prostheses by reviewing all available long-term follow-up data. We herein present the clinical and hemodynamic data derived from patients 2-5 years after TAVI and describe all published cases of prosthesis degeneration.
The development of orthodontics has improved thanks to the introduction of adhesives which are physically and chemically akin to tooth enamel and brackets. These materials often fall short of the required durability standards. The objective was to evaluate the real strength of the adhesives and to introduce a proprietary device, generating multiple vectors of strength between dental brackets and the surface of enamel. 11 types of adhesive materials have been studied. 990 applications have been made using removed teeth, followed by a randomised creation of 11 groups containing 90 samples each. The threshold values of the strength needed to break the brackets off were determined in torsional, shear and tension strength tests. A comparison between tensometric and planimetric methods was made by means based on ARI index. Resistance was highest for torsional stress, weaker for shear stress and the weakest for tension stress. A correlation was found between tensometric results. The study attempted to systematise the methodology of direct tests.
The adhesive systems have the function to establish the connection between the restorative material and dental tissue, therefore it is of fundamental importance, because failures in the adhesive interface can reduce the life of a dental restoration. This study investigated the possibility of using the adhesive layer as a chlorhexidine modified release system evaluating their impact on the properties of these systems as well as evaluating the impact of these systems on immediate and post-aging dentin adhesion. Were used a matrix with BisGMA, UDMA, HEMA and TEGDMA copolymer and clay particles (Dellite 67G); associated with a chlorhexidine and a camphorquinone photoinitiator system. The properties of these systems were evaluated by the XRD, FTIR spectrophotometer, flexural strength, elasticity modulus, drug release, enzymatic inhibition and dentin adhesion resistance. The presence of the clay can raise the mechanical properties of the adhesive systems engendering a more resistant hybrid layer and led to a more sustained release of chlorhexidine in the systems, allowing a longer effective period of MMP-2 inhibition. The hypothesis that the addition of clays as release modulators could increase the effectiveness of these drugs in inhibiting the dentin's MPPs and consequently enhancing the adhesive durability was confirmed. These results indicate that the controlled release of chlorhexidine is able to reduce the process of loss of adhesion presenting itself as a promising system to increase the longevity of dental restorations.
- MeSH
- biokompatibilní materiály MeSH
- časové faktory MeSH
- chlorhexidin chemie MeSH
- dentin chemie MeSH
- dentinová adheziva MeSH
- jíl chemie MeSH
- léky s prodlouženým účinkem MeSH
- pevnost v tahu MeSH
- testování materiálů MeSH
- uvolňování léčiv * MeSH
- zubní materiály * MeSH
- Publikační typ
- časopisecké články MeSH
AIMS: Single-shot pulmonary vein isolation can improve procedural efficiency. To assess the capability of a novel, expandable lattice-shaped catheter to rapidly isolate thoracic veins using pulsed field ablation (PFA) in healthy swine. METHODS AND RESULTS: The study catheter (SpherePVI; Affera Inc) was used to isolate thoracic veins in two cohorts of swine survived for 1 and 5 weeks. In Experiment 1, an initial dose (PULSE2) was used to isolate the superior vena cava (SVC) and the right superior pulmonary vein (RSPV) in six swine and the SVC only in two swine. In Experiment 2, a final dose (PULSE3) was used for SVC, RSPV, and left superior pulmonary vein (LSPV) in five swine. Baseline and follow-up maps, ostial diameters, and phrenic nerve were assessed. Pulsed field ablation was delivered atop the oesophagus in three swine. All tissues were submitted for pathology. In Experiment 1, all 14/14 veins were isolated acutely with durable isolation demonstrated in 6/6 RSPVs and 6/8 SVC. Both reconnections occurred when only one application/vein was used. Fifty-two and 32 sections from the RSPVs and SVC revealed transmural lesions in 100% with a mean depth of 4.0 ± 2.0 mm. In Experiment 2, 15/15 veins were isolated acutely with 14/15 veins (5/5 SVC, 5/5 RSPV, and 4/5 LSPV) durably isolated. Right superior pulmonary vein (31) and SVC (34) sections had 100% transmural, circumferential ablation with minimal inflammation. Viable vessels and nerves were noted without evidence of venous stenosis, phrenic palsy, or oesophageal injury. CONCLUSION: This novel expandable lattice PFA catheter can achieve durable isolation with transmurality and safety.
- MeSH
- fibrilace síní * diagnóza chirurgie patologie MeSH
- katetrizační ablace * škodlivé účinky metody MeSH
- katétry MeSH
- prasata MeSH
- studie proveditelnosti MeSH
- vena cava superior chirurgie MeSH
- venae pulmonales * chirurgie patologie MeSH
- výsledek terapie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: Current recommendations support surgical treatment of atrial fibrillation (AF) in patients indicated for cardiac surgery. These procedures are referred to as concomitant and may be carried out using radiofrequency energy or cryo-ablation. This study aimed to assess the electrophysiological findings in patients undergoing concomitant cryo-ablation. METHODS: Patients with non-paroxysmal AF undergoing coronary artery bypass grafting and/or valve repair/replacement were included in the trial if concomitant cryo-ablation was part of the treatment plan according to current guidelines. The patients reported in this study were assigned to undergo staged percutaneous radiofrequency catheter ablation (PRFCA), i.e., hybrid treatment, as a part of the SURHYB trial protocol. RESULTS: We analyzed 103 patients who underwent PRFCA 105 ± 35 days after surgery. Left and right pulmonary veins (PVs) were found isolated in 65 (63.1%) and 63 (61.2%) patients, respectively. The LA posterior wall isolation and mitral isthmus conduction block were found in 38 (36.9%) and 18 (20.0%) patients, respectively. Electrical reconnections (gaps) in the left PVs were more often localized superiorly than inferiorly (57.9% vs. 26.3%, P = 0.005) and anteriorly than posteriorly (65.8% vs. 31.6%, P = 0.003). Gaps in the right PVs were more equally distributed anteroposteriorly but dominated in superior segments (72.5% vs. 40.0%, P = 0.003). There was a higher number of gaps on the roof line compared to the inferior line (131 (67.2%) vs. 67 (42.2%), P < 0.001). Compared to epicardial cryo-ablation, endocardial was more effective in creating PVs and LA posterior wall isolation (P < 0.05). Cryo-ablation using nitrous oxide (N20) or argon (Ar) gas as cooling agents was similarly effective (P = NS). CONCLUSIONS: The effectiveness of surgical cryo-ablation in achieving transmural and durable lesions in the left atrium is surprisingly low. Gaps are located predominantly in the superior and anterior portions of the PVs and on the roof line. Endocardial cryo-ablation is more effective than epicardial ablation, irrespective of the cooling agent used.
- MeSH
- fibrilace síní * chirurgie MeSH
- katetrizační ablace * metody MeSH
- koronární bypass metody MeSH
- kryochirurgie * metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- venae pulmonales * chirurgie MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: Ring annuloplasty reduces the septal-lateral diameter (SLD) indirectly by circumferential annular cinching and frequently results in the recurrence of mitral regurgitation (MR) in patients with functional MR (FMR). Our goal was to report the results from the trial and the 2-year post-trial surveillance data. We evaluated whether direct reduction of the SLD with a transannular mitral bridge could achieve significant and durable MR reduction in patients with FMR. METHODS: In a prospective trial, 34 consecutive patients with FMR had a mitral bridge implanted surgically. Primary end points were MR ≤1+ at 1, 3 and 6 months postimplant and freedom from subsequent surgical mitral valve repair or replacement. RESULTS: Thirty-two of 34 (94.1%) patients met the primary end points with MR ≤1+ at 6 months. At 2 years, there were no strokes or device-related adverse events. At 2 years, MR was reduced from 3.32 ± 0.47 to 0.50 ± 0.83 (P ≤ 0.001) with ≤1+ MR in 33/34 patients, including 4 reinterventions for periprosthetic recurrent MR ≥3 without mitral bridge explants or conventional mitral repair or replacement. At 2 years, the mean mitral gradient was 2.15 ± 0.82 mmHg; the mitral annular SLD decreased from 40.4 ± 2.91 mm to 28.9 ± 1.55 mm (P ≤ 0.001). The left ventricular ejection fraction increased (57.9 ± 10.4-62.4 ± 9.7%; P ≤ 0.001). The New York Heart Association functional class improved (2.19 ± 0.76-1.41 ± 0.61; P ≤ 0.001). CONCLUSIONS: The single-centre trial data indicate that direct reduction in the SLD with a mitral bridge is feasible, safe and efficacious in patients with FMR. Validation in a larger population of patients and comparison to conventional annuloplasty ring are necessary. CLINICAL TRIAL REGISTRATION NUMBER: NCT03511716.
- MeSH
- anuloplastika mitrální chlopně * škodlivé účinky přístrojové vybavení mortalita statistika a číselné údaje MeSH
- lidé středního věku MeSH
- lidé MeSH
- mitrální chlopeň patofyziologie chirurgie MeSH
- mitrální insuficience patofyziologie chirurgie MeSH
- prospektivní studie MeSH
- recidiva MeSH
- senioři MeSH
- srdeční chlopně umělé MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- pozorovací studie MeSH
