Twenty-year experience following aortic valve replacement in patients younger than 60 years of age.

OBJECTIVE: Reports on long-term outcomes of surgical aortic valve replacement (AVR) for patients aged < 60 years are scarce in Japan. Hence, we aimed to evaluate these outcomes in patients aged < 60 years. METHODS: Between March 2000 and December 2020, 1477 patients underwent aortic valve replacement. In total, 170 patients aged < 60 years who underwent aortic valve replacement were recruited. Patients aged < 18 years were excluded. Patient data collected from the operative records and follow-up assessments were reviewed. RESULTS: The mean age was 49 ± 9 years, and 64.1% of patients were male. One-hundred-and-fifty-two patients (89.4%) underwent aortic valve replacement with a mechanical valve and 18 (10.6%) with a bioprosthetic valve. The mean follow-up period was 8.1 ± 5.5 years. No operative mortality occurred, and in-hospital mortality occurred in one patient (0.6%). Ten late deaths occurred, with seven cardiac-related deaths. The overall survival rate was 95.4 ± 1.7%, 93.9 ± 2.3%, 90.6 ± 3.9%, and 73.2 ± 11.8% at 5, 10, 15, and 20 years, respectively. Freedom from major bleeding was 96.4 ± 1.6% at 5, 10, and 15 years, and 89.0 ± 7.3% at 20 years. Freedom from thromboembolic events was 98.7 ± 1.3%, 97.3 ± 1.9%, 90.5 ± 4.5%, and 79.0 ± 11.3% at 5, 10, 15, and 20 years, respectively. Freedom from valve-related reoperation was 99.4 ± 0.6% at 5 years, 97.8 ± 1.7% at 10 and 15 years, and 63.9 ± 14.5% at 20 years. CONCLUSIONS: Patients aged < 60 years undergoing aortic valve replacement with a high mechanical valve implantation rate had favorable long-term outcomes.

Transthoracic echocardiographic Doppler metrics in evaluating bioprosthetic tricuspid valve dysfunction.

PURPOSE: There is currently limited information on the utility of transthoracic echocardiography (TTE)-derived Doppler parameters for assessing bioprosthetic tricuspid valve (BTV) dysfunction. Our study aimed to establish the precision and appropriate reference ranges for routinely collected transthoracic Doppler parameters in the assessment of BTV dysfunction. METHODS: We retrospectively evaluated 100 BTV patients who underwent TTE. Based on redo surgical confirmation or more than 2 repeat TTE or transesophageal echocardiography (TEE) examinations, patients were allocated to normal (n = 61), regurgitant (n = 24), or stenotic (n = 15) BTV group. Univariate and multivariate binary logistic regression were performed to identify TTE Doppler parameters that detected BTV dysfunction. RESULTS: The VTI ratio (VTITV/VTILVOT) was the most accurate Doppler parameter for detecting BTV dysfunction, with a ratio of >2.8 showing 84.6% sensitivity and 90.2% specificity. VTI ratio > 3.2, mean gradient (MGTV) > 6.2 mmHg and pressure half-time > 218 ms detected significant BTV stenosis, with sensitivities of 100%, 93.3% and 93.3% and specificities of 82.4%, 75.3% and 87.1%, respectively. After multivariate analysis, the VTI ratio > 2.8 (OR = 9.00, 95% CI = 2.13-41.61, p = .003) and MGTV > 5.1 mmHg (OR = 6.50, 95% CI = 1.69-27.78, p = .008) were the independent associations of BTV dysfunction. With these cutoff values, 75.0%-92.2% of normal and 62.5%-96.0% of dysfunctional BTV were identified. CONCLUSIONS: Doppler parameters from TTE can accurately identify BTV dysfunction, particularly with VTI ratio > 2.8 and MGTV > 5.1 mmHg, to assess the need for additional testing with TEE.

Surgical Technique And Clinical Implications Of Transcatheter Aortic Valve Bioprosthesis Explantation.

There has been a worldwide rapid adoption of transcatheter aortic valve replacement (TAVR) as an alternative to surgical aortic valve replacement (SAVR) for patients with severe aortic stenosis. Currently, more TAVR explants with SAVRs are performed than TAVR-in TAV. TAVR explantation is a technically hazardous procedure mainly due to significant aortic neo-endothelialization which incorporates the TAVR valve. Surgical techniques for TAVR explantation are not well established and surgeon experience at present is limited. In this manuscript, we describe our technique for surgical explantation of transcatheter aortic bioprosthesis. Familiarity with the procedure and its clinical implications is essential for all cardiac surgeons.

Comparison of apixaban versus aspirin for the prevention of latent bioprosthetic aortic valve thrombosis: study protocol for a prospective randomized trial.

BACKGROUND: The optimal antithrombotic strategy early after aortic valve replacement surgery with a biological valve remains controversial due to lack of high-quality evidence. Either oral anticoagulants or acetylsalicylic acid should be considered for the first 3 months. Hypo-attenuated leaflet thickening on cardiac computed tomography has been associated with latent bioprosthetic valve thrombosis and may be prevented with anticoagulation. We hypothesize that anticoagulation with apixaban is superior to single antiplatelet therapy with acetylsalicylic acid in reducing hypo-attenuated leaflet thickening of bioprosthetic aortic valve prostheses. METHODS: In this prospective, open-label, randomized trial, patients undergoing isolated aortic valve replacement surgery with rapid deployment bioprosthetic valves will be randomized. The treatment group will receive 5 mg of apixaban twice a day for the first 3 months and 100 mg of acetylsalicylic acid thereafter. The control group will be administered 100 mg of acetylsalicylic acid once a day, indefinitely. After the 3-month treatment period, a contrast-enhanced electrocardiogram-gated cardiac computed tomography will be performed to identify hypo-attenuated leaflet thickening of the bioprosthetic valve. The primary objective of the study is to assess the impact of apixaban on the prevention of hypo-attenuated leaflet thickening at 3 months. The secondary and exploratory endpoints will be clinical outcomes and safety profiles of the two strategies. DISCUSSION: Antithrombotic therapy after aortic valve replacement is used to prevent valve thrombosis and systemic thromboembolism. Latent bioprosthetic valve thrombosis is a precursor of clinically significant prosthetic valve dysfunction or thromboembolic events. The hallmark feature of latent bioprosthetic valve thrombosis is hypo-attenuated leaflet thickening on cardiac computed tomography. Subclinical leaflet thrombosis occurs frequently in bioprosthetic aortic valves, more commonly in transcatheter than in surgical valves. There is no evidence on the effect of direct oral anticoagulants on the incidence of hypo-attenuated leaflet thickening after surgical aortic valve replacement with rapid deployment bioprostheses. TRIAL REGISTRATION: ClinicalTrials.gov NCT06184113. Registered on December 28, 2023.

Computer-Assisted Transcatheter Mitral Valve Implantation for Valve-in-Valve Procedures.

Transcatheter mitral valve-in-valve is an alternative to high-risk reoperation on a failing bioprosthesis. It entails specific challenges such as left ventricular outflow tract obstruction. We propose a patient-specific augmented imaging based on preoperative planning to assist the procedure. Valve-in-valve simulation was performed to represent the optimal level of implantation and the neo-left ventricular outflow tract. These data were combined with intraoperative images through a real-time 3D/2D registration tool. All data were collected retrospectively on one case (pre and per-procedure imaging). We present for the first time an intraoperative guidance tool in transcatheter mitral valve-in-valve procedure.

Examining the typical hemodynamic performance of nearly 3000 modern surgical aortic bioprostheses.

OBJECTIVES: The objective of this analysis was to assess the normal haemodynamic performance of contemporary surgical aortic valves at 1 year postimplant in patients undergoing surgical aortic valve replacement for significant valvular dysfunction. By pooling data from 4 multicentre studies, this study will contribute to a better understanding of the effectiveness of surgical aortic valve replacement procedures, aiding clinicians and researchers in making informed decisions regarding valve selection and patient management. METHODS: Echocardiograms were assessed by a single core laboratory. Effective orifice area, dimensionless velocity index, mean aortic gradient, peak aortic velocity and stroke volume were evaluated. RESULTS: The cohort included 2958 patients. Baseline age in the studies ranged from 70.1 ± 9.0 to 83.3 ± 6.4 years, and Society of Thoracic Surgeons risk of mortality was 1.9 ± 0.7 to 7.5 ± 3.4%. Twenty patients who had received a valve model implanted in fewer than 10 cases were excluded. Ten valve models (all tissue valves; n = 2938 patients) were analysed. At 1 year, population mean effective orifice area ranged from 1.46 ± 0.34 to 2.12 ± 0.59 cm2, and dimensionless velocity index, from 0.39 ± 0.07 to 0.56 ± 0.15. The mean gradient ranged from 8.6 ± 3.4 to 16.1 ± 6.2 mmHg with peak aortic velocity of 1.96 ± 0.39 to 2.65 ± 0.47 m/s. Stroke volume was 75.3 ± 19.6 to 89.8 ± 24.3 ml. CONCLUSIONS: This pooled cohort is the largest to date of contemporary surgical aortic valves with echocardiograms analysed by a single core lab. Overall haemodynamic performance at 1 year ranged from good to excellent. These data can serve as a benchmark for other studies and may be useful to evaluate the performance of bioprosthetic surgical valves over time. CLINICAL TRIAL REGISTRATION NUMBER: NCT02088554, NCT02701283, NCT01586910 and NCT01531374.

Thrombocytopenia after sutureless and standard stented aortic valve replacement: a retrospective analysis of risk factors, clinical course, and early outcome.

OBJECTIVES: Thrombocytopenia following Perceval aortic valve replacement has been described previously with variable outcome. Studies have lacked a robust analysis of platelet fluctuation and factors affecting it. We aimed to statistically describe the trend in thrombocyte variability as compared with conventional aortic valve replacement, and to assess predictors as well as impact on associated outcomes. METHODS: One hundred consecutive patients with first-time Perceval were retrospectively compared to 219 patients after Perimount Magna Ease valve replacement. The primary outcome was the serial thrombocyte count on day 0-6. Generalized estimating equations were used to analyse the data using fixed-effect models: for the effect of the post-operative day on platelet count, and random-effect models estimating both time-variant (platelets) and time in-variant variables (valve type, age, LV function, pre-op platelet level). RESULTS: Perceval patients were older (72 ± 1 vs 68 ± 1 years, p < 0.01) with higher NYHA status (3(2-3) vs 2(1-2), p < 0.001). Mean platelet count in the sutureless group was lowest on day 2 (91.9 ± 31.6 vs 121.7 ± 53.8 × 103 µl-1), and lower on day 4 (97.9 ± 44) and 6 (110.6 ± 61) compared to the conventional group (157.2 ± 60 and 181.7 ± 79) but did not result in a higher number of transfusions, bleeding or longer hospital stay (p > 0.05). Reduced platelet count was a strong predictor of red cell transfusion in the conventional (p = 0.016), but not in the sutureless group (p = 0.457). Age (Coef -1.025, 95%CI-1.649--0.401, p < 0.001) and CPB-time (Coef 0.186, 95%CI-0.371--0.001, p = 0.048) were predictors for lower platelet levels. CONCLUSION: Considering the older patient profile treated with Perceval, postoperative thrombocytopenia does not impact on outcome in terms of transfusions, complications or hospital stay.

Bioprosthetic mitral valve thrombosis: the role of cardiac CT in diagnosis and guiding the management.

A patient in his 60s with a bioprosthetic aortic and mitral valve replacement presented with dyspnoea, tiredness and dizziness 2 years postoperatively. Transthoracic echocardiography showed mitral valve stenosis and increased pulmonary artery pressure suggesting bioprosthetic valve failure. Cardiac CT confirmed the diagnosis of bioprosthetic mitral valve thrombosis. Treatment with anticoagulation resulted in a remarkable improvement of the valve area and gradient and complete resolution of the thrombus. Herein, we report a case of rare bioprosthetic mitral valve thrombosis.

Tissue requirements for the application of aortic valve neocuspidization - appropriate pericardium properties and homogeneity?

OBJECTIVE: Aortic valve neocuspidization (AVNeo) using autologous pericardium is a promising technique. Expected advantages are reduced immune response, appropriate biomechanics and lower treatment expenses. Nevertheless, autologous pericardium can be affected by patient's age and comorbidities. Usually, glutaraldehyde (GA) - fixed bovine pericardium is the basic material for aortic valve prostheses, easy available and carefully pre-examined in a standardized fabrication process. Aim of the study is the verification of autologous pericardial tissue homogeneity by analysing tissue thickness, biomechanics and extracellular matrix (ECM) composition. METHODS: Segments of human GA-fixed pericardium selected by the surgeon based on visual criteria for cusp pre-cut and remaining after surgical AV replacement were investigated in comparison to bovine standard tissue treated equivalently. Pericardium sampling was performed at up to three positions of each sutured cusp for histological or biomechanical analysis, according to tissue availability. RESULTS AND CONCLUSIONS: Human pericardia exhibited a higher heterogeneity in collagen content, density of vessel structures and elastic moduli. Thickness, vessel density and collagen and elastin content differed significantly between the species. In contrast, significant interindividual differences were detected in most properties investigated for human pericardial samples but only for tissue thickness in bovine tissues. Higher heterogeneity of human pericardium, differing vessel and collagen content compared to bovine state-of-the-art material might be detrimental for long term AV functionality or deterioration and have to be intensely investigated in patients follow up after autologous cusp replacement.

[Catheter-based and surgical treatment for aortic valve diseases]. / Katheterbasierte und operative Therapie bei Aortenvitien.

The pathophysiology of aortic valve diseases is of predominantly degenerative nature, characterized by calcific aortic valve stenosis, which is associated with a reduction in prognosis. The prevalence of aortic valve insufficiency also increases with advancing age. Timely causal treatment is crucial in the management of aortic valve diseases. Following the indication for intervention, the heart team plays a central role in evaluating the results and making therapeutic decisions that consider the patient's preferences. In the assessment of treatment options, considerations regarding the long-term perspective are particularly crucial, especially in younger patients. The most common therapeutic approach for aortic valve diseases is the introduction of a new valve prosthesis. In the majority of cases, this is now achieved through catheter-based implantation of a bioprosthetic heart valve, known as transcatheter aortic valve implantation (TAVI). Open surgical aortic valve replacement (AVR) is favored in younger patients with low surgical risk or in the case that TAVI is not feasible. In AVR, both biological and the longest-lasting mechanical prosthesis types are used. Surgical repair techniques are primarily applied in cases of aortic valve regurgitation. Notably, TAVI, as well as surgical procedures for the treatment of aortic valve diseases, have undergone significant advancements in recent years, including expanded indications for TAVI and, on the surgical side, in particular the development of minimally invasive surgical techniques.

Aortic Regurgitation, Time to Aortic Valve Reintervention, and Mortality in Degenerated Trifecta Versus Non-Trifecta Bioprosthesis.

On July 31, 2023, the Trifecta valve was withdrawn from the market after concerns regarding early (≤5 years) structural valve deterioration (SVD), mainly as aortic regurgitation (AR). Our aim was to determine the timing, mechanism, and impact of bioprosthetic SVD in patients who underwent redo aortic valve replacement (redo-AVR) with either redo-SAVR or valve-in-valve transcatheter aortic valve replacement (TAVR) using Trifecta versus other bioprosthetic valves. Patients who underwent redo-AVR for SVD at our institution were categorized into 2 groups based on the valve type: Trifecta versus non-Trifecta. Multivariate Cox proportional hazard model and Kaplan-Meier curves were used to compare mortality. A total of 171 patients were included; 58 (34%) had previous SAVR with a Trifecta valve and 113 (66%) with non-Trifecta valve. A total of 103 patients (60%) underwent valve-in-valve TAVR and 68 redo-SAVR (40%). The age, gender, and Society of Thoracic Surgeons score were similar between Trifecta and non-Trifecta groups. In patients with bioprosthetic valves requiring redo-AVR, Trifecta valves had an earlier onset of greater than moderate AR (4.5 vs 11.9 years, p <0.001) and earlier time to redo-AVR (5.5 vs 12 years, p <0.001). AR was more common as the mechanism of SVD in Trifecta versus non-Trifecta valves (55.2% vs 30.1%, p = 0.006). All-cause adjusted mortality from index SAVR was higher in the Trifecta than in non-Trifecta group (hazard ratio 4.1, 95% confidence interval 1.5 to 11.5, p = 0.007). In conclusion, compared with non-Trifecta valves, Trifecta valves exhibit early SVD primarily as AR and progress rapidly to significant SVD requiring redo-AVR. Mortality is significantly higher with Trifecta than in non-Trifecta valves, potentially impacting the results of SAVR versus TAVR studies.

Devastating fungal endocarditis involving ascending aorta in a patient with a history of aortic valve replacement: a case report.

BACKGROUND: Fungal endocarditis is a rare but serious condition associated with high mortality rates. Various predisposing factors contribute to its occurrence, such as underlying cardiac abnormalities, cardiac surgeries, prosthetic cardiac devices, and central venous catheters. Diagnosing fungal endocarditis, particularly Aspergillus, poses challenges, often complicated by negative blood cultures. CASE PRESENTATION: This report details a case of extensive ascending aorta involvement in Aspergillus endocarditis (AE) in a 24-year-old man with a history of bioprosthesis aortic valve replacement (AVR). Three months post-AVR, he presented with pericardial effusion and aortic rupture, leading to a redo biological valved conduit aortic root replacement (Bentall surgery). Despite the intervention, the tubular graft exhibited extensive Aspergillus involvement, resulting in graft disruption and significant peri-aortic infection. A second redo procedure involving aortic homograft root replacement was performed. Unfortunately, the patient succumbed two days after the surgery. CONCLUSION: A combined approach of medical and surgical therapies is recommended to manage fungal endocarditis. Despite efforts, the mortality rate associated with Aspergillus endocarditis remains unacceptably high, with no significant difference observed between combination therapy and antifungal treatment alone. Further research is essential to explore novel therapeutic strategies and improve outcomes for patients with this challenging condition.

Perceval-S over time. Clinical outcomes after ten years of usage.

BACKGROUND: Perceval-S has become a reliable and commonly used option in surgical aortic valve replacement (AVR) since its first implantation in humans 15 years ago. Despite the fact that this aortic valve has been proven efficient enough in the short and mid-term period, there is still lack of evidence for the long-term outcomes. MATERIALS AND METHODS: This is an observational retrospective study in a high-volume cardiovascular center. Pertinent data were collected for all the patients in whom Perceval-S was implanted from 2013 to 2020. RESULTS: The total number of patients was 205 with a mean age 76.4 years. Mean survival time was 5.5 years (SE = 0.26). The overall survival probability of patients undergoing aortic valve replacement with Perceval-S at 6 months was 91.0% (Standard Error SE = 2.0%), at one year 88.4% (SE = 2.3%) and at 5-years 64.8% (SE = 4.4%). A detrimental cardiac event leading to death was the probable cause of death in 35 patients (55.6%). The initiation of Transcatheter Aortic Valve Replacement (TAVR) program in our center in 2017 was associated with a decline in the number of very high-risk patients treated with sutureless bioprosthesis. This fact is demonstrated by the significant shift towards lower surgical risk cases, as median Euroscore II was reduced from 5,550 in 2016 to 3,390 in 2020. Mini sternotomy was implemented in 79,5% of cases favoring less invasive approach. Low incidence of reinterventions, patient prosthesis mismatch and structural valve degeneration was detected. CONCLUSIONS: The survival rate after aortic valve replacement with implantation of Perceval-S is satisfactory in the long-term follow-up. Cases of bioprosthesis dysfunction were limited. Mini sternotomy was used in the majority of cases. TAVR initiation program impacted on the proportion of patients treated with Perceval-S with reduction of high-risk patients submitted to surgery.

Optimization of Enzymatic and Chemical Decellularization of Native Porcine Heart Valves for the Generation of Decellularized Xenografts.

One of the most important medical interventions for individuals with heart valvular disease is heart valve replacement, which is not without substantial challenges, particularly for pediatric patients. Due to their biological properties and biocompatibility, natural tissue-originated scaffolds derived from human or animal sources are one type of scaffold that is widely used in tissue engineering. However, they are known for their high potential for immunogenicity. Being free of cells and genetic material, decellularized xenografts, consequently, have low immunogenicity and, thus, are expected to be tolerated by the recipient's immune system. The scaffold ultrastructure and ECM composition can be affected by cell removal agents. Therefore, applying an appropriate method that preserves intact the structure of the ECM plays a critical role in the final result. So far, there has not been an effective decellularization technique that preserves the integrity of the heart valve's ultrastructure while securing the least amount of genetic material left. This study demonstrates a new protocol with untraceable cells and residual DNA, thereby maximally reducing any chance of immunogenicity. The mechanical and biochemical properties of the ECM resemble those of native heart valves. Results from this study strongly indicate that different critical factors, such as ionic detergent omission, the substitution of Triton X-100 with Tergitol, and using a lower concentration of trypsin and a higher concentration of DNase and RNase, play a significant role in maintaining intact the ultrastructure and function of the ECM.

Novel valve-in-surgical bioprosthetic transcatheter aortic valve replacement: Undermining iatrogenic coronary obstruction with radiofrequency needle (UNICORN).

An 86-year-old female with history of surgical aortic valve replacement presented with clinical signs of heart failure. Echocardiography revealed a reduction in left ventricular systolic function and severe bioprosthetic aortic valve dysfunction. This is the first reported case of valve-in-valve transcatheter aortic valve replacement with concomitant undermining iatrogenic coronary obstruction with radiofrequency needle procedure in a surgical bioprosthetic valve.

Continuous or interrupted pledgeted suture technique in stented bioprosthetic aortic valve replacement: a comparison of in-hospital outcomes.

BACKGROUND: There is ambiguity in the literature regarding the continuous suture technique (CST) for aortic valve replacement (AVR). At our center, there has been a gradual shift towards CST over the interrupted pledgeted technique (IPT). This study aims at comparing outcomes for both techniques. METHODS: We performed a retrospective analysis of a single-center study of patients undergoing AVR between January 2011 and July 2020. Patients were divided into two groups: Continuous suture technique and interrupted pledget-reinforced sutures. The pre-operative and In-hospital clinical characteristics and echocardiographic hemodynamics (i.e. transvalvular gradients and paravalvular leakage) were compared between CST and IPT. RESULTS: We compared 791 patients with CST to 568 patients with IPT (median age: 73 and 74 years, respectively, p = 0.02). In CST there were 35% concomitant procedure vs. 31% in IPT (p = 0.16). Early mortality was 3.2% in CST versus 4.8% in IPT (p = 0.15), and a second cross-clamp due to a paravalvular-leak in 0.5% vs. 1.2%, respectively (p = 0.22). The CST was not associated with new-onset conduction-blocks mandating pacemaker implants(OR 1.07, 95% CI 0.54-2.14; P = 0.85). The postoperative gradients on echocardiography were lower in CST compared to IPT, especially in smaller annuli (peak gradients: 15.7mmHg vs. 20.5mmHg, in valve size < 23 mm, p < 0.001). CONCLUSIONS: The continuous suture technique was associated with lower postoperative gradients and shorter cross-clamp time compared to interrupted pledgeted technique. Differences in paravalvular leaks were non-significant, although slightly less in the continuous suture technique. There were no further differences in valve-related complications. Hence, continues suture technique is safe, with better hemodynamics compared to the interrupted pledgeted technique. This may be of clinical importance, especially in smaller size annular size.

Successful valve-in-valve transcatheter intervention to treat severe stenosis of a 38-year-old tricuspid bioprosthesis.

A 60-year-old man presented with breathlessness. Nearly four decades previously, he had required three operations for Staphylococcus aureus infective endocarditis of the tricuspid valve and had received a bioprosthetic valve. He had critical tricuspid bioprosthesis stenosis which was treated successfully by valve-in-valve transcatheter tricuspid valve replacement using a balloon-expandable transcatheter heart valve. One year after intervention, the patient is well with no tricuspid valve stenosis or regurgitation.

Bio-inspired magnetically responsive silicone cilia: fabrication strategy and interaction with biological mucus

Cilia are biological structures essential to drive the mobility of secretions and maintain the proper function of the respiratory airways. However, this motile self-cleaning process is significantly compromised in the presence of silicone tracheal prosthesis, leading to biofilm growth and impeding effective treatment. To address this challenge and enhance the performance of these devices, we propose the fabrication of magnetic silicone cilia, with the prospect of their integration onto silicone prostheses. The present study presents a fabrication method based on magnetic self-assembly and assesses the interaction behavior of the cilia array with biological mucus. This protocol allows for the customization of cilia dimensions across a wide range of aspect ratios (from 6 to 85) and array densities (from 10 to 80 cilia/mm2) by adjusting the fabrication parameters, offering flexibility for adjustments according to their required characteristics. Furthermore, we evaluated the suitability of different cilia arrays for biomedical applications by analyzing their interaction with bullfrog mucus, simulating the airways environment. Our findings demonstrate that the fabricated cilia are mechanically resistant to the viscous fluid and still exhibit controlled movement under the influence of an external moving magnet. A correlation between cilia dimensions and mucus wettability profile suggests a potential role in facilitating mucus depuration, paving the way for further advancements aimed at enhancing the performance of silicone prostheses in clinical settings.

[Sudden Chest Pain due to Early Bioprosthetic Valve Dysfunction:Report of a Case].

We report a case of bioprosthetic valve dysfunction and acute aortic valve regurgitation. The case was a 75-year-old female who had sudden onset chest pain. ST-segment depression in several leads on electrocardiogram( ECG) suggested acute coronary syndrome. Coronary angiography showed no significant stenosis in coronary arteries. Transesophageal echocardiography revealed severe aortic regurgitation, suggesting that angina was caused by myocardial ischemia associated with acute aortic regurgitation. She was diagnosed as having bioprosthetic valve dysfunction, and underwent redo aortic valve replacement. One leaflet of the bioprosthetic valve was torn along the stent post and caused bioprosthetic valve dysfunction. Failed bioprosthetic valve was removed and replaced by a mechanical valve.