192 research outputs found

    An electro-responsive hydrogel for intravascular applications: an in vitro and in vivo evaluation

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    There is a growing interest in using hydrogels for biomedical applications, because of more favourable characteristics. Some of these hydrogels can be activated by using particular stimuli, for example electrical fields. These stimuli can change the hydrogel shape in a predefined way. It could make them capable of adaptation to patient-specific anatomy even post-implantation. This is the first paper aiming to describe in vivo studies of an electro-responsive, Pluronic F127 based hydrogel, for intravascular applications. Pluronic methacrylic acid hydrogel (PF127/MANa) was in vitro tested for its haemolytic and cytotoxic effects. Minimal invasive implantation in the carotid artery of sheep was used to evaluate its medium-term biological effects, through biochemical, macroscopic, radiographic, and microscopic evaluation. Indirect and direct testing of the material gave no indication of the haemolytic effects of the material. Determination of fibroblast viability after 24 h of incubation in an extract of the hydrogel showed no cytotoxic effects. Occlusion was obtained within 1 h following in vivo implantation. Evaluation at time of autopsy showed a persistent occlusion with no systemic effects, no signs of embolization and mild effects on the arterial wall. An important proof-of-concept was obtained showing biocompatibility and effectiveness of a pluronic based electro-responsive hydrogel for obtaining an arterial occlusion with limited biological impact. So the selected pluronic-methacrylic acid based hydrogel can be used as an endovascular occlusion device. More importantly it is the first step in further development of electro-active hydrogels for a broad range of intra-vascular applications (e.g. system to prevent endoleakage in aortic aneurysm treatment, intra-vascular drug delivery)

    Cardiac surgery in the time of the novel coronavirus:Why we should think to a new normal

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    On 11 March 2020, the World Health Organization declared the SARS-CoV-2 outbreak a pandemic. At the time of writing, 24 May 2020 more than 5 million individuals have been tested positive and the death toll was over 330 000 deaths worldwide. The initial data pointed out the tight bond between cardiovascular diseases and worse health outcomes in COVID19-patients. Epidemiologically speaking, there is an overlap between the age-groups more affected by COVID-related death and the age-groups in which Cardiac Surgery has its usual base of patients. The Cardiac Surgery Departments have to think to anew normal: since the virus will remain endemic in the society, dedicated pathways or even dedicated Teams are pivotal to treat safely the patients, in respect of the safety of the health care workers. Moreover, we need a keen eye on deciding which pathologies have to be treated with priority: Coronary artery Disease showed a higher mortality rate in patients affected by COVID19, but it is, however, reasonable to think that all the cardiac pathologies affecting the lung circulation-such as symptomatic severe mitral diseases or aortic stenosis-might deserve a priority access to treatment, to increase the survival rate in case of an acquired-Coronavirus infection later on

    Functional and biomechanical evaluation of a completely recellularized stentless pulmonary bioprosthesis in sheep

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    ObjectiveIn a previous study we showed that recellularization of a stentless bioprosthetic valve is stimulated 1 month after implantation in the pulmonary position, when its matrix (acellular photo-oxidized bovine pericardium) was preseeded by intraperitoneal implantation during a 3-day period.MethodsThe present study reports on the functional and biomechanical properties of such valves (n = 19) in sheep up to 5 months after implantation. Similar valves (n = 20) that were not intraperitoneally preseeded served as controls.ResultsRecellularization was partial in control valves and excessive in preseeded valves: 66% versus 223% of cellularity of native valves, respectively (P < .05). The valves were endothelialized and contained interstitial cells depositing new matrix (collagens and elastin). However, phenotyping revealed an increased proportion of cells with contractile properties (30%–40% alpha smooth muscle actin+) in both groups. Intraperitoneally seeded valves had thicker and shorter leaflets that were associated with mildly increased peak gradients and regurgitation. Characterization of the matrix properties revealed a gradually degrading matrix (±25% loss of collagen organization at 5 months) and a concomitant alteration of its biomechanical properties, that is, decreased strength, stiffness, and maximum force. However, overall valve function remained intact, and the biomechanical properties of the whole valves were superior to that of the native valves.ConclusionThe ectopic in vivo seeding paradigm provides full recellularization. However, the volume fraction of the cellular phenotypes is not optimal, resulting in inadequate remodeling of the valves

    Avoiding oversizing in sutureless valves leads to lower transvalvular gradients and less permanent pacemaker implants postoperatively.

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    peer reviewed[en] OBJECTIVES: The aim of this study was to evaluate the impact of changing the sizing strategy in aortic valve replacement using the Perceval sutureless prosthesis on haemodynamic outcomes and postoperative pacemaker implantation. METHODS: Retrospective analysis of patients implanted with the Perceval valve between 2007 and 2019 was performed by comparing patients implanted before the modification of sizing strategy (OLD group) and after (NEW group). The outcome parameters evaluated were the implanted prosthesis size, haemodynamical profile and postoperative pacemaker implantation. RESULTS: The entire patient cohort (784 patients) consisted of 52% female patients, with a mean age of 78.53 [standard deviation (SD): 5.8] years and a mean EuroSCORE II of 6.3 (range 0.7-76). In 55.5% of cases, surgery was combined. The NEW cohort had more male patients (54.6% vs 43.4%) (P = 0.002). Mean implanted valve size, corrected for body surface area, was significantly lower in the NEW cohort (13.1, SD: 1.4 vs 13.5, SD: 1.4 mm/m2, P < 0.001). The 30-day mortality was 3.4%. Peak and mean transvalvular gradients at discharge were significantly lower in the NEW versus OLD groups: 24.4 mmHg (SD: 9.2) versus 28.4 mmHg (SD: 10.3) (P < 0.001) and 13.6 mmHg (SD: 5.3) versus 15.5 mmHg (SD: 6.0) (P < 0.001). The mean effective opening area and the indexed effective opening area, respectively, increased from 1.5 cm2 (SD: 0.5) and 0.85 cm2/m2 (SD: 0.27) in the OLD group to 1.7 cm2 (SD: 0.5) and 0.93 cm2/m2 (SD: 0.30) in the NEW group (P < 0.001). No difference was found in paravalvular leakage ≥1/4. Centrovalvular leakage ≥1/4 significantly decreased from 18% to 7.9% (P < 0.001). With the new sizing, the new postoperative pacemaker implantation rate decreased significantly from 11% to 6.1% (P = 0.016). CONCLUSIONS: Correct sizing of sutureless aortic valves is crucial to obtain the best possible haemodynamics and avoid complications

    Predicting hospitalisation-associated functional decline in older patients admitted to a cardiac care unit with cardiovascular disease: a prospective cohort study

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    Up to one in three of older patients who are hospitalised develop functional decline, which is associated with sustained disability, institutionalisation and death. This study developed and validated a clinical prediction model that identifies patients who are at risk for functional decline during hospitalisation. The predictive value of the model was compared against three models that were developed for patients admitted to a general medical ward.; A prospective cohort study was performed on two cardiac care units between September 2016 and June 2017. Patients aged 75 years or older were recruited on admission if they were admitted for non-surgical treatment of an acute cardiovascular disease. Hospitalisation-associated functional decline was defined as any decrease on the Katz Index of Activities of Daily Living between hospital admission and discharge. Predictors were selected based on a review of the literature and a prediction score chart was developed based on a multivariate logistic regression model.; A total of 189 patients were recruited and 33% developed functional decline during hospitalisation. A score chart was developed with five predictors that were measured on hospital admission: mobility impairment = 9 points, cognitive impairment = 7 points, loss of appetite = 6 points, depressive symptoms = 5 points, use of physical restraints or having an indwelling urinary catheter = 5 points. The score chart of the developed model demonstrated good calibration and discriminated adequately (C-index = 0.75, 95% CI (0.68-0.83) and better between patients with and without functional decline (chi; 2; = 12.8, p = 0.005) than the three previously developed models (range of C-index = 0.65-0.68).; Functional decline is a prevalent complication and can be adequately predicted on hospital admission. A score chart can be used in clinical practice to identify patients who could benefit from preventive interventions. Independent external validation is needed

    Sutureless and rapid deployment implantation in bicuspid aortic valve: results from the sutureless and rapid-deployment aortic valve replacement international registry.

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    Background Benefits of sutureless and rapid deployment (SURD) bioprostheses in bicuspid aortic valves (BAV) are controversial. The aim of this study is to report the outcomes of patients undergoing aortic valve replacement (AVR) for BAV from the Sutureless and Rapid-Deployment Aortic Valve Replacement International Registry (SURD-IR). Methods Of the 4,636 patients who received primary isolated SURD-AVR between 2007 and 2018, 191 (4.1%) BAV patients underwent AVR with SURD valve. Results Overall 30-day mortality was 1.6%. The Intuity valve was implanted in 53.9% of cases, whereas the Perceval was implanted in 46.1%. Rate of stroke for isolated AVR was 4.2%. No case of endocarditis, thromboembolism, myocardial infarction, valve dislocation or structural valve deterioration was reported in the early phase. Rate of pacemaker implantation and moderate-severe aortic regurgitation (AR) were 7.9% and 3.7%, respectively. Conclusions BAV is not considered a contraindication for the implantation of SURD valves. However, detailed information of aortic root geometry as well as the knowledge of some technical considerations are mandatory for a good outcome

    Durability of bioprosthetic aortic valve replacement in patients under the age of 60 years - 1-year follow-up from the prospective INDURE registry.

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    OBJECTIVES We report 1-year safety and clinical outcomes in patients <60 years undergoing bioprosthetic surgical aortic valve intervention. METHODS The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, multicentre registry to assess clinical outcomes of patients <60 years. Patients with planned SAVR with or without concomitant replacement of the ascending aorta and/or coronary bypass surgery were included. Time-related valve safety, haemodynamic performance, and quality of life (QoL) at 1 year were assessed. RESULTS 421 patients were documented with a mean age of 53.5 years, 76.5% being male, and 27.2% in NYHA class III/IV. Outcomes within 30 days included cardiovascular-related mortality (0.7%), time-related valve safety (VARC-2; 5.8%), thromboembolic events (1.7%), valve-related life-threatening bleeding (VARC-2; 4.3%), and permanent pacemaker implantation (3.8%). QoL was significantly increased at 6 months and sustained at 1 year. Freedom from all-cause mortality at 1 year was 98.3% (95%CI 97.1;99.6) and 81.8% were NYHA I vs. 21.9% at baseline. No patient developed structural valve deterioration Stage 3 (VARC-3). Mean aortic pressure gradient was 12.6 mmHg at 1 year and effective orifice area was 1.9 cm2. CONCLUSIONS The 1-year data from the INSPIRIS RESILIA valve demonstrate good safety and excellent haemodynamic performance as well as an early QoL improvement. CLINICALTRIALS NUMBER NCT03666741

    Durability of bioprosthetic aortic valves in patients under the age of 60 years - Rationale and design of the international INDURE registry

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    Background: There is an ever-growing number of patients requiring aortic valve replacement (AVR). Limited data is available on the long-term outcomes and structural integrity of bioprosthetic valves in younger patients undergoing surgical AVR. Methods: The INSPIRIS RESILIA Durability Registry (INDURE) is a prospective, open-label, multicentre, international registry with a follow-up of 5 years to assess clinical outcomes of patients younger than 60 years who undergo surgical AVR using the INS
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