Search results for "Prosthesis"
showing 10 items of 719 documents
Computer Modeling for the Prediction of Thoracic Aortic Stent Graft Collapse
2011
OBJECTIVE: To assess the biomechanical implications of excessive stent protrusion into the aortic arch in relation to thoracic aortic stent graft (TASG) collapse by simulating the structural load and quantifying the fluid dynamics on the TASG wall protrusion extended into a model arch. METHODS: One-way coupled fluid-solid interaction analyses were performed to investigate the flow-induced hemodynamic and structural loads exerted on the proximal protrusion of the TASG and aortic wall reconstructed from a patient who underwent traumatic thoracic aortic injury repair. Mechanical properties of a Gore TAG thoracic endoprosthesis (W. L. Gore and Assoc, Flagstaff, Ariz) were assessed via experimen…
An In Vitro Phantom Study on the Role of the Bird-Beak Configuration in Endograft Infolding in the Aortic Arch.
2015
Purpose: To assess endograft infolding for excessive bird-beak configurations in the aortic arch in relation to hemodynamic variables by quantifying device displacement and rotation of oversized stent-grafts deployed in a phantom model. Methods: A patient-specific, compliant, phantom pulsatile flow model was reconstructed from a patient who presented with collapse of a Gore TAG thoracic endoprosthesis. Device infolding was measured under different flow and pressure conditions for 3 protrusion extensions (13, 19, and 24 mm) of the bird-beak configuration resulting from 2 TAG endografts with oversizing of 11% and 45%, respectively. Results: The bird-beak configuration with the greatest protr…
Regurgitant flow in apparently normal valve prostheses: improved detection and semiquantitative analysis by transesophageal two-dimensional color-cod…
1990
In 128 patients with apparently normally functioning prosthetic valves ( n = 136) in the aortic position ( n = 79) and the mitral position ( n = 57), the prevalence of transprosthetic regurgitant flow was studied by use of transthoracic and transesophageal two-dimensional color-coded Doppler echocardiography. With the transthoracic approach, regurgitant flow was detected in early systole or diastole for 28% of the mitral prostheses and for 29% of the aortic prostheses. With transesophageal color-coded Doppler echocardiography, regurgitant jets were visualized for 95% of the mitral prostheses and for 44% of the aortic prostheses. In 40% of the Bjork-Shiley prostheses and 88% of the St. Jude …
Heart valve tissue engineering: how far is the bedside from the bench?
2015
Heart disease, including valve pathologies, is the leading cause of death worldwide. Despite the progress made thanks to improving transplantation techniques, a perfect valve substitute has not yet been developed: once a diseased valve is replaced with current technologies, the newly implanted valve still needs to be changed some time in the future. This situation is particularly dramatic in the case of children and young adults, because of the necessity of valve growth during the patient's life. Our review focuses on the current status of heart valve (HV) therapy and the challenges that must be solved in the development of new approaches based on tissue engineering. Scientists and physicia…
Treatment of isolated ascending aortic aneurysm by off-pump epiaortic wrapping is safe and durable.
2016
OBJECTIVES: Isolated ascending aortic aneurysm (iAA) is usually treated by open graft repair requiring sternotomy, cardiopulmonary bypass (CPB) and cardioplegia. This approach carries significant mortality in older patients or those presenting with comorbidities. We report an original series of patients presenting with iAA and treated with epiaortic wrapping by using a synthetic mesh. This less invasive aortic repair technique allows reducing the aortic diameter to a predefined value and is performed without CPB. METHODS: Data from patients presenting with an iAA and treated with the wrapping technique (WT) by polypropylene/polyester mesh from November 2006 to July 2015 were collected. The …
Outcomes of aortic valve repair according to valve morphology and surgical techniques
2012
OBJECTIVES: The aim of this study was to assess the impact of aortic valve morphology and different surgical aortic valve repair techni- ques on long-term clinical outcomes. METHODS: Between February 2003 and May 2010, 216 patients with aortic insufficiency underwent aortic valve repair in our institu- tion. Ages ranged between 26 and 82 years (mean 53 ± 15 years). Aortic valve dysfunctions, according to functional classification, were: type I in 55 patients (25.5%), type II in 126 (58.3%) and type III in 35 (16.2%). Sixty-six patients (27.7%) had a bicuspid valve. Aortic valve repair techniques included sub-commissural plasty in 138 patients, plication in 84, free-edge reinforcement in 80,…
A multicentre European registry to evaluate the Direct Flow Medical transcatheter aortic valve system for the treatment of patients with severe aorti…
2016
Aims Our aim was to assess the clinical outcomes of the Direct Flow Medical Transcatheter Aortic Valve System (DFM-TAVS), when used in routine clinical practice. Methods and results This is a prospective, open-label, multicentre, post-market registry of patients treated with DFM-TAVS according to approved commercial indications. Echocardiographic and angiographic data were evaluated by an independent core laboratory and adverse events were adjudicated and classified according to VARC-2 criteria by an independent clinical events committee. The primary endpoint was freedom from all-cause mortality at 30 days post procedure. Secondary endpoints included procedural, early safety and efficacy en…
Value and limitations of transesophageal echocardiography in the evaluation of aortic prostheses.
1993
Results of 34 transesophageal (TEE) studies in patients with suspected aortic prosthetic dysfunction were compared with transthoracic echocardiographic (TTE) results and to anatomic findings. Mass lesions noted at surgery (autopsy) were correctly described in 93% by TEE versus 43% by TTE. Abscesses were detected in 88% by TEE versus 18% by TTE. Bioprosthetic degeneration was visualized in 88% versus 38% and prosthetic obstruction correctly identified in 75% versus 50% by TEE and TTE, respectively. Anatomic aortic regurgitant lesions were identified in 96% by TEE versus 77% by TTE, whereas the correct origin was detected in 88% of cases by TEE versus 54% of cases by TTE. TEE provides valuabl…
Early structural degeneration of Mitroflow aortic valve: Another issue in addition to the mismatch?
2018
We reported two cases of early structural valve degeneration (SVD) with Mitroflow prosthesis in aortic position in patients above the age of 65 years. Microscopic aspects have been analysed to investigate the intrinsic mechanism of SVD. New techniques to improve the structure and the preservation of this prosthesis are needed in order to reduce potential dangerous early complications.
Chronic atrial fibrillation in presence of aortic stenosis in a patient with polysplenia syndrome.
2013
We report a rare case of “situs viscerum ambiguous” with polysplenia syndrome, in a 69 year old female patient with aortic stenosis and chronic atrial fibrillation. The presenting symptom was dyspnoea on moderate exertion and an ECG showed supra ventricular arrhythmia. Patients trans-thoracic echocardiogram revealed a dilated left atrium, reduced ejection fraction, mild tricuspid regurgitation, moderate-severe pulmonary hypertension and severe aortic stenosis. The patient was successfully treated with a replacement of her aortic valve and ascending aorta.