8 research outputs found
Ultrasonic irrigation flows in root canals:effects of ultrasound power and file insertion depth
Ultrasonic irrigation during root canal treatment can enhance biofilm disruption. The challenge is to improve the fluid flow so that the irrigant reaches areas inaccessible to hand instrumentation. The aim of this study is to experimentally investigate how the flow field and hydrodynamic forces induced by ultrasonic irrigation are influenced by the ultrasound power and file insertion depth. A root canal phantom was 3D printed and used as a mold for the fabrication of a PDMS channel. An ultrasonic instrument with a #15 K-file provided the irrigation. The flow field was studied by means of Particle Image Velocimetry (PIV). The time averaged velocity and shear stress distributions were found to vary significantly with ultrasound power. Their maximum values increase sharply for low powers and up to a critical power level. At and above this setting, the flow pattern changes, from the high velocity and shear stress region confined in the vicinity of the tip, to one covering the whole root canal domain. Exceeding this threshold also induces a moderate increase in the maximum velocities and shear stresses. The insertion depth was found to have a smaller effect on the measured velocity and shear stresses. Due to the oscillating nature of the flow, instantaneous maximum velocities and shear stresses can reach much higher values than the mean, especially for high powers. Ultrasonic irrigation will benefit from using a higher power setting as this does produce greater shear stresses near the walls of the root canal leading to the potential for increased biofilm removal
Mechanisms, predictors, and evolution of severe peri-device leaks with two different left atrial appendage occluders.
AIMS
Incomplete left atrial appendage occlusion (LAAO) due to peri-device leak (PDL) is a limitation of the therapy. The Amulet IDE trial is the largest randomized head-to-head trial comparing the Amulet and Watchman 2.5 LAAO devices with fundamentally different designs. The predictors and mechanistic factors impacting differences in PDLs within the Amulet IDE trial are assessed in the current analysis.
METHODS AND RESULTS
An independent core lab analysed all images for the presence or absence of severe PDL (>5 mm). The incidence, mechanistic factors, predictors using propensity score-matched controls, and evolution of severe PDLs through 18 months were assessed. Of the 1878 patients randomized in the trial, the Amulet occluder had significantly fewer severe PDLs than the Watchman device at 45 days (1.1 vs. 3.2%, P < 0.001) and 12 months (0.1 vs. 1.1%, P < 0.001). Off-axis deployment or missed lobes were leading mechanistic PDL factors in each device group. Larger left atrial appendage (LAA) dimensions including orifice diameter, landing zone diameter, and depth predicted severe PDL with the Watchman device, with no significant anatomical limitations noted with the Amulet occluder. Procedural and device implant predictors were found with the Amulet occluder attributed to the learning curve with the device. A majority of Watchman device severe PDLs did not resolve over time through 18 months.
CONCLUSION
The dual-occlusive Amplatzer Amulet LAA occluder provided improved LAA closure compared with the Watchman 2.5 device. Predictors and temporal observations of severe PDLs were identified in the Amulet IDE trial.
CLINICAL TRIAL REGISTRATION
https://clinicaltrials.gov Unique identifier NCT02879448
A Comparative Assessment of Echocardiographic Parameters for Determining Primary Mitral Regurgitation Severity Using Magnetic Resonance Imaging as a Reference Standard.
BACKGROUND: The American Society of Echocardiography (ASE) guidelines suggest the use of several echocardiographic methods to assess mitral regurgitation severity using an integrated approach, without guidance as to the weighting of each parameter. The purpose of this multicenter prospective study was to evaluate the recommended echocardiographic parameters against a reference modality and develop and validate a weighting for each echocardiographic measure of mitral regurgitation severity.
METHODS: This study included 112 patients who underwent evaluation with echocardiography and magnetic resonance imaging (MRI). Echocardiographic parameters recommended by the ASE were included and compared with MRI-derived regurgitant volume (MRI-RV).
RESULTS: Echocardiographic parameters that correlated best with MRI-RV were proximal isovelocity surface area (PISA) radius (r = 0.65, P \u3c .0001), PISA-derived effective regurgitant orifice area (r = 0.65, P \u3c .0001), left ventricular end-diastolic volume (r = 0.56, P \u3c .0001), and PISA-derived regurgitant volume (r = 0.52, P \u3c .0001). In the linear regression models PISA-derived effective regurgitant orifice area, PISA-derived regurgitant volume, left ventricular end-diastolic volume, and the presence of a flail leaflet independently predicted MRI-RV.
CONCLUSION: Echocardiographic parameters of mitral regurgitation as recommended by the ASE had moderate correlations with MRI-RV. The best predictors of MRI-RV were PISA-derived effective regurgitant orifice area, PISA-derived regurgitant volume, left ventricular end-diastolic volume, and the presence of a flail leaflet, suggesting that these parameters should be weighted more heavily than other echocardiographic parameters in the application of the ASE-recommended integrated approach
Discordance between MRI and echocardiography in the assessment of mitral regurgitation severity: prediction of surgical response suggests mri may be more accurate
Midterm outcomes of aortic valve replacement using a rapid-deployment valve for aortic stenosis: TRANSFORM trialCentral MessagePerspective
Background: The use of rapid-deployment valves (RDVs) has been shown to reduce the operative time for surgical aortic valve replacement (AVR). Long-term core laboratory–adjudicated data are scarce, however. Here we report final 7-year data on RDV use. Methods: TRANSFORM was a prospective, nonrandomized, multicenter, single-arm trial implanting a stented bovine pericardial valve with an incorporated balloon-expandable sealing frame. A prior published 1-year analysis included 839 patients from 29 centers. An additional 46 patients were enrolled and implanted, for a total of 885 patients. Annual clinical and core laboratory–adjudicated echocardiographic outcomes were collected through 8 years. Primary endpoints were structural valve deterioration (SVD), all-cause reintervention, all-cause valve explantation, and all-cause mortality. Secondary endpoints included hemodynamic performance assessed by echocardiography. The mean duration of follow-up was 5.0 ± 2.0 years. Results: The mean patient age was 73.3 ± 8.2 years. Isolated AVR was performed in 62.1% of the patients, and AVR with concomitant procedures was performed in 37.9%. Freedom from all-cause mortality at 7 years was 76.0% for isolated AVR and 68.2% for concomitant AVR. Freedom from SVD, all-cause reintervention, and valve explantation at 7 years was 97.5%, 95.7%, and 97.8%, respectively. The mean gradient and effective orifice area at 7 years were 11.1 ± 5.3 mm Hg and 1.6 ± 0.3 cm2, respectively. Paravalvular leak at 7 years was none/trace in 88.6% and mild in 11.4%. In patients undergoing isolated AVR, the cumulative probability of pacemaker implantation was 13.9% at 30 days, 15.5% at 1 year, and 21.8% at 7 years. Conclusions: AVR for aortic stenosis using an RDV is associated with low rates of late adverse events. This surgical pericardial tissue platform provides excellent and stable hemodynamic performance through 7 years
Left Atrial to Coronary Sinus Shunting for Treatment of Symptomatic Heart Failure.
Background: Heart failure (HF) is associated with both mortality and a significant decline in health status. Inter-atrial shunting is increasingly being investigated as a novel therapeutic option.
Objectives: The ALT FLOW Early Feasibility Study was designed to evaluate the safety of the Edwards left atrial to coronary sinus APTURETM Transcatheter Shunt System in patients with symptomatic HF.
Methods: 18 centers enrolled patients with symptomatic HF with a pulmonary capillary wedge pressure (PCWP) \u3e15mmHg at rest or 25mmHg during exercise.
Results: Between May 2018 and September 2022, 87 patients underwent attempted APTURETM shunt implantation. Mean age was 71 years, and 53% were male. At baseline mean LVEF was 59% with 90% of the patients being NYHA III. Device success was achieved in 78 (90%) of patients with no device occlusions or associated adverse events identified after implantation. The primary safety outcome occurred in only 2 (2.3%) patients at 30 days. At 6 months health status improved: 68% of participants achieved NYHA I-II status, with a 23-point improvement (p\u3c0.0001, 95% CI [17, 29]) in the Kansas City Cardiomyopathy Questionnaire overall summary score. Also at 6 months, 20-watt exercise pulmonary capillary wedge pressure was -7mmHg lower (p\u3c0.0001, 95% CI [-11, -4]) without change in right atrial pressure or other right heart function indices.
Conclusions: In this single-arm experience, the APTURETM Transcatheter Shunt System in patients with symptomatic HF was observed to be safe and resulted in reduction in PCWP and clinically meaningful improvements in HF symptoms and quality of life indices.
Keywords: HFpEF; HFrEF; atrial shunting; coronary sinus; heart failure; inter-atrial shunting; left atrial
Randomized Comparison of Transcatheter Edge-to-Edge Repair for Degenerative Mitral Regurgitation in Prohibitive Surgical Risk Patients.
BACKGROUND: Severe symptomatic degenerative mitral regurgitation (DMR) has a poor prognosis in the absence of treatment, and new transcatheter options are emerging.
OBJECTIVES: The CLASP IID randomized trial (NCT03706833) is the first to evaluate the safety and effectiveness of the PASCAL system compared to the MitraClip system in patients with significant symptomatic DMR. In this report, we present the primary safety and effectiveness endpoints for the trial.
METHODS: Patients with 3+ or 4+ DMR at prohibitive surgical risk were assessed by a central screening committee and randomized 2:1 (PASCAL:MitraClip). Study oversight also included an echocardiographic core laboratory and a clinical events committee. The primary safety endpoint was a composite major adverse event (MAE) rate at 30 days. The primary effectiveness endpoint was the proportion of patients with MR ≤2+ at 6 months.
RESULTS: A pre-specified interim analysis in 180 patients demonstrated non-inferiority of the PASCAL system vs. MitraClip system for the primary safety and effectiveness endpoints, MAE: 3.4% vs. 4.8%, MR ≤2+: 96.5% vs. 96.8%, respectively. Functional and quality-of-life outcomes significantly improved in both groups (p
CONCLUSIONS: The CLASP IID trial demonstrated safety and effectiveness of the PASCAL system and met non-inferiority endpoints, expanding transcatheter treatment options for prohibitive surgical risk patients with significant symptomatic DMR