Stent Geometry Reconstruction Using Imaging Techniques

2013 ◽  
Author(s):  
Daria Cosentino ◽  
Iwona Zwierzak ◽  
Vanessa Diaz-Zuccarini ◽  
John W. Fenner ◽  
Silvia Schievano ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Imaging Techniques ◽  
Diagnostic Tools ◽  
Clinical Images ◽  
Stent Geometry ◽  
Geometrical Data ◽  
Transcatheter Valve ◽  
Valve Implantation

Stents are most commonly used in the relief of coronary artery stenosis, but in the last decade have found increasing applications in the treatment of other cardiovascular disease and in particular in heart valve replacement [1]. In transcatheter valve implantation, acquisition of high temporal and spatial resolution images during stenting procedure and patients’ follow-up is required to help the correct positioning of the device and to assess the mechanical performance over time. The imaging techniques routinely used for this purpose are 2D X-ray fluoroscopy and 3D computed tomography (CT), and recent studies have demonstrated their value as diagnostic tools [1–3]. However, these image modalities carry errors and the resulting information might not be accurate enough to be employed in engineering analyses of stent deformations, mechanics, dynamics and fracture. In this study, we aim to evaluate the errors of conventionally used clinical images (fluoroscopy and CT) and post-processing by comparison with ultra-high resolution micro-CT (μCT) as gold standard. Additionally, an optical image acquisition method and a high-radiation CT scan were evaluated as potential techniques to acquire geometrical data that could be used for computational and in-vitro engineering experiments.

Transcatheter Valve-in-Valve Aortic Valve Implantation: 16-Month Follow-Up

2009 ◽  
Vol 88 (4) ◽  
pp. 1322-1324 ◽  
Author(s):  
Jian Ye ◽  
John G. Webb ◽  
Anson Cheung ◽  
Jean-Bernard Masson ◽  
Ronald G. Carere ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Valve In Valve ◽  
Aortic Valve Implantation ◽  
Transcatheter Valve ◽  
Valve Implantation

scholarly journals Cone Beam Computed Tomography-guided Management of Cervical Perforative Internal Resorption in Permanent Mandibular First Molar

2016 ◽  
Vol 6 (3) ◽  
pp. 73-77
Author(s):  
Rasika A Naik ◽  
Manoj M Ramugade ◽  
Nilofar B Attar ◽  
Kishor D Sapkale
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Imaging Techniques ◽  
Glass Ionomer Cement ◽  
Cone Beam ◽  
Diagnostic Tools ◽  
Resin Modified Glass Ionomer ◽  
Mandibular First Molar ◽  
Ionomer Cement

ABSTRACT Internal resorption in the permanent dentition is a rare pathologic condition. Clinical differentiation of perforative cervical internal resorption from cervical external resorption is considered to be a challenging task. Advanced imaging techniques, such as cone beam computed tomography (CBCT) have proven vital diagnostic tools in the detection and management of these lesions. Management of a perforated internal resorption needs comprehensive endorestorative and periodontal approach. This article describes 1 year follow-up of the successfully managed perforative cervical internal resorption in permanent mandibular first molar. The affected tooth was endodontically treated, and the resorptive defect was restored with resin-modified glass ionomer cement (RMGIC) through periodontal flap surgery. How to cite this article Naik RA, Ramugade MM, Attar NB, Sapkale KD. Cone Beam Computed Tomography-guided Management of Cervical Perforative Internal Resorption in Permanent Mandibular First Molar. Int J Prosthodont Restor Dent 2016;6(3):73-77.

scholarly journals First successful transcatheter valve-in-valve implantation into a failed mechanical prosthetic aortic valve facilitated by fracturing of the leaflets: a case report

2021 ◽  
Vol 5 (7) ◽  
Author(s):  
Christian Butter ◽  
Ralf-Uwe Kühnel ◽  
Frank Hölschermann
Keyword(s):  
High Risk ◽  
Aortic Valve ◽  
Heart Function ◽  
Severe Heart Failure ◽  
Left Ventricular ◽  
Heart Team ◽  
Valve In Valve ◽  
Transcatheter Valve ◽  
Valve Implantation

Abstract Background Degenerated and failed bioprosthetic cardiac valves can safely be treated with transcatheter valve-in-valve implantation in patients at high risk for reoperation. So far, non-functional mechanical valves must be treated with a surgical redo. Breaking the carbon leaflets before implanting a transcatheter valve into the remaining ring has never been described before. Case summary Here, we present the case of a 65-year-old male patient with severe heart failure, poor left ventricular function based on a fully immobile disc of his mechanical bileaflet aortic valve implanted 7 years ago. After the heart team declined to reoperate the patient due to his extremely high risk, we considered a transcatheter valve-in-valve implantation as the ultimate treatment approach. After successful interventional cracking of the leaflets in vitro, this approach, together with implanting a balloon-expandable transcatheter aortic valve replacement (TAVR) into the remaining ring, was performed under cerebral protection. The intervention resulted in a fully functional TAVR, improvement of heart function, and early discharge from the hospital. Discussion This case demonstrates the possibility to implant a transcatheter valve successfully into a non-functional mechanical bileaflet aortic prosthesis after fracturing the carbon discs while the brain is protected by a filter system. Critical steps of the procedure were identified. This new therapeutic approach might be offered to a limited patient cohort who is not eligible for a surgical redo.

Abstract 16958: Comparison of Clinical and Hemodynamic Outcomes Between Redo Surgical Aortic Valve Replacement versus Transcatheter Valve in Valve in Patient With Failed Aortic Bioprostheses

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sebastien Hecht ◽  
Jeremy Bernard ◽  
Lionel Tastet ◽  
nancy cote ◽  
Erwan Salaun ◽  
...  
Keyword(s):  
Lower Risk ◽  
Surgical Aortic Valve Replacement ◽  
Increased Risk ◽  
Long Term Follow Up ◽  
Valve In Valve ◽  
Transcatheter Valve ◽  
Valve Implantation ◽  
Long Term Mortality

Introduction: Transcatheter valve-in-valve implantation (ViV) has emerged as an alternative to redo surgery (REDO) for the treatment of failed surgical aortic bioprostheses. However, there are few studies comparing clinical and hemodynamic outcomes between REDO and ViV in both the short- and long- term follow-up. Objective: The aim of this study was to compare hemodynamic and clinical outcomes between REDO and ViV. Methods: A total of 184 patients who underwent REDO or ViV at our institution between 2003 and 2017 were included in this study. Clinical and transthoracic echocardiography (TTE) data were collected for each patient. TTE was performed prior and after the reintervention and were retrospectively analyzed in an echocardiography core laboratory. An inverse propensity treatment weighting (IPTW) was used to compare outcomes between groups. Results: 104 patients underwent REDO and 80 underwent ViV. Prevalence of suboptimal valve hemodynamics (mean gradient ≥ 20 mmHg and/or ≥ moderate aortic regurgitation) following reintervention was higher in ViV group (29.8% vs. 61.3%, p<0.001), the rate of novel permanent pacemaker tended to be higher with REDO (10.6% vs. 3.8%, p=0.08). During a median follow-up of 5.0 (3.7-7.5) years, 60 patients died. There was a trend toward higher rate of 30-day mortality in the REDO vs. ViV group (8.6% vs. 2.5%, OR [95% CI]: 3.70[0.77-17.6], p=0.10) and a trend toward lower risk of long-term mortality in REDO (HR [95% CI]: 0.61[0.33-1.14], p=0.12). In multivariate cox proportional analysis adjusted for age, sex, EuroSCORE 2, ViV was significantly associated with increased risk of long-term mortality (HR [95% CI]: 2.28[1.25-4.15], p=0.03). Results were confirmed in IPTW analyses (30-day mortality in REDO vs. ViV: 3.39[3.25-3.53], p<0.001; long-term mortality: 0.70[0.69-0.71], p<0.001). Conclusions: ViV was associated with lower risk of 30-day but higher risk of long-term mortality compared to REDO.

scholarly journals Extracellular non-coding RNA signatures of the metacestode stage of Echinococcus multilocularis

2020 ◽  
Vol 14 (11) ◽  
pp. e0008890
Author(s):  
María Eugenia Ancarola ◽  
Gabriel Lichtenstein ◽  
Johannes Herbig ◽  
Nancy Holroyd ◽  
Mara Mariconti ◽  
...  
Keyword(s):  
Echinococcus Multilocularis ◽  
Diagnostic Tools ◽  
Helminth Parasites ◽  
Negative Results ◽  
Helminth Infections ◽  
Polarized Secretion ◽  
Non Coding Rna ◽  
Novel Biomarkers

Extracellular RNAs (ex-RNAs) are secreted by cells through different means that may involve association with proteins, lipoproteins or extracellular vesicles (EV). In the context of parasitism, ex-RNAs represent new and exciting communication intermediaries with promising potential as novel biomarkers. In the last years, it was shown that helminth parasites secrete ex-RNAs, however, most work mainly focused on RNA secretion mediated by EV. Ex-RNA study is of special interest in those helminth infections that still lack biomarkers for early and/or follow-up diagnosis, such as echinococcosis, a neglected zoonotic disease caused by cestodes of the genus Echinococcus. In this work, we have characterised the ex-RNA profile secreted by in vitro grown metacestodes of Echinococcus multilocularis, the casuative agent of alveolar echinococcosis. We have used high throughput RNA-sequencing together with RT-qPCR to characterise the ex-RNA profile secreted towards the extra- and intra-parasite milieus in EV-enriched and EV-depleted fractions. We show that a polarized secretion of small RNAs takes place, with microRNAs mainly secreted to the extra-parasite milieu and rRNA- and tRNA-derived sequences mostly secreted to the intra-parasite milieu. In addition, we show by nanoparticle tracking analyses that viable metacestodes secrete EV mainly into the metacestode inner vesicular fluid (MVF); however, the number of nanoparticles in culture medium and MVF increases > 10-fold when metacestodes show signs of tegument impairment. Interestingly, we confirm the presence of host miRNAs in the intra-parasite milieu, implying their internalization and transport through the tegument towards the MVF. Finally, our assessment of the detection of Echinococcus miRNAs in patient samples by RT-qPCR yielded negative results suggesting the tested miRNAs may not be good biomarkers for this disease. A comprehensive study of the secretion mechanisms throughout the life cycle of these parasites will help to understand parasite interaction with the host and also, improve current diagnostic tools.

scholarly journals Implantation of three transcatheter aortic valves for embolization of two valves caused by under-expansion: a case report

2020 ◽  
Author(s):  
Masaki Tsuda ◽  
Ryu Shutta ◽  
Masami Nishino ◽  
Jun Tanouchi
Keyword(s):  
Aortic Valve ◽  
Balloon Dilation ◽  
In Vitro Test ◽  
Aortic Valves ◽  
Transcatheter Aortic Valve ◽  
Case Summary ◽  
Vitro Test ◽  
Valve Implantation

Abstract Background Transcatheter aortic valve embolization is one of the serious complications of transcatheter aortic valve implantation (TAVI). We present a case of TAVI that needed implantation of three transcatheter aortic valves owing to the embolization of two self-expandable valves (SEVs). Case summary An 88-year-old woman underwent TAVI using a 26-mm SEV. After valve deployment, the SEV embolized to the ascending aorta during the removal of the delivery system (DS) of the SEV (DS-SEV) from the SEV. An additional SEV was implanted, which also embolized upwards. Multi-directional fluoroscopy revealed extreme under-expansion of the second SEV, which caused valve embolization due to catching of the DS-SEVs in the SEVs. Finally, a 23-mm balloon-expandable valve was successfully implanted, which was also under expanded on fluoroscopic assessment. The patient was stable without sequelae at the 1-month follow-up. Discussion Pre-procedurally predicting SEV under-expansions was difficult because pre-procedural computed tomography revealed no massive calcification on the aortic valve, and fluoroscopy indicated adequate expansion of the SEVs at the angle where the valves were deployed. We verified the possibility of catching of a DS-SEV in an under-expanded SEV in an in vitro test, which showed that the DS-SEV was caught in the extremely under-expanded SEV. Furthermore, balloon dilation might release the catch of the DS-SEV by changing the DS-SEV position. Therefore, we recommend performing multi-directional fluoroscopy to evaluate SEV expansion before DS-SEV removal from an SEV. Furthermore, if catching of a DS-SEV occurs, balloon dilation might be useful for releasing the catch and safely removing the DS-SEV.

Femoral transcatheter valve-in-valve implantation as alternative strategy for failed aortic bioprostheses: A single-centre experience with long-term follow-up

2020 ◽  
Vol 306 ◽  
pp. 25-34
Author(s):  
Tomasz Stankowski ◽  
Sleiman Sebastian Aboul-Hassan ◽  
Farzaneh Seifi Zinab ◽  
Volker Herwig ◽  
Piotr Stępiński ◽  
...  
Keyword(s):  
Alternative Strategy ◽  
Single Centre ◽  
Single Centre Experience ◽  
Long Term Follow Up ◽  
Valve In Valve ◽  
Transcatheter Valve ◽  
Valve Implantation
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