Objectives The CHAGALL study is a prospective, first-in-human early feasibility study evaluating the technical feasibility, the long-term safety and device durability of a novel chordal replacement system for the treatment of primary degenerative mitral regurgitation. Methods Five patients with symptomatic severe primary degenerative mitral regurgitation due to isolated central posterior leaflet prolapse or flail underwent surgical implantation of the ChordArt chordal replacement system through a left atrial approach under cardiopulmonary bypass combined with ring annuloplasty. Clinical and transthoracic echocardiographic follow-up was prospectively performed at discharge and through 60 months. Results Technical device success was achieved in all patients. Mitral regurgitation was reduced to none or trace immediately after implantation and remained stable throughout the 5-year follow-up. No device-related major adverse events, structural device failure, implant dislodgement, chordal rupture, reoperation, or rehospitalization occurred. Reverse cardiac remodeling was observed, including reduction in left ventricular end-diastolic diameter and left atrial volume, while left ventricular function remained preserved during long-term follow-up. Conclusion Surgical implantation of the ChordArt chordal replacement system was simple to perform and demonstrated excellent long-term technical durability and sustained clinical performance over 5 years. These findings support further clinical evaluation of this technology and the ongoing development of a fully transcatheter transseptal delivery platform.

Cardiac assist devices based on dielectric elastomer actuators (DEAs) offer a promising alternative to conventional mechanical circulatory support by providing soft and adaptive mechanical assistance. However, existing DEA-based systems face significant limitations in energy efficiency and effective hemodynamic modulation. This study presents a novel vacuum-enhanced DEA-based counterpulsation device and evaluates its performance in a porcine in-vivo model. We investigated two distinct implementation configurations: a direct attachment to the descending aorta and an integration into a bypass circuit mimicking an ascending aortic attachment. The device was actuated in synchronization with the cardiac cycle to provide real-time mechanical unloading. The results demonstrate that the vacuum-enhanced DEA system significantly improved diastolic augmentation (Mean: 39.1 ± 11.7%; Range: 29.2 to 55.0%) and achieved superior left ventricular unloading, marked by a remarkable reduction in end-diastolic pressure (Mean: −126.1 ± 65.6%; Range: −188.3 to −67.1%). Furthermore, the device reduced stroke work (Mean: −12.3 ± 14.0%; Range: −24.2 to 4.4%) and increased stroke volume (Mean: 3.9 ± 2.2%; Range: 2.5 to 7.1%) compared to baseline (device off). These findings establish vacuum-enhanced DEA actuation as a highly viable and impactful approach for next-generation cardiac assist devices, paving the way for further clinical optimization and application.

ObjectiveDespite advancements in surgical techniques, many patients born with congenital heart defects (CHD) require repeated reinterventions due to the limitations of materials used in congenital cardiac surgery (CCS). Traditional biogenic polymers, such as bovine or equine pericardium, are prone to calcification, have limited durability, and fail to adapt to the growth of infants. This study aims to address these challenges by investigating bacterial cellulose (BC) as a promising material for CCS.MethodsVariability in patch quality from previous studies was addressed by refining the production protocol taking advantage of optical density (OD) measurements. After a 72 h incubation, patches were harvested and tested mechanically with burst pressure and uniaxial strain testing. BC's biomechanical properties were further explored by modifying nutrient concentrations, creating different media groups (N10, N30, N50). Hybrid patches combining BC with electrospun polyurethane (ESP-PU) were developed using a specially designed 3D-printed flask to ensure uniform coating and integration.ResultsThe initial bacterial concentration significantly influenced cellulose yield and growth rate, with static cultures outperforming shaken ones. Nutrient-enriched media (N10, N30, N50) produced cellulose with greater elasticity and strength compared to standard C-Medium, with stiffness correlating to nutrient concentration. Inflation tests showed that N10 and N30 samples withstood higher pressures than N50, which, despite being stiffer, performed worse under rapid inflation. All samples, however, maintained pressures above physiological levels. Scanning electron microscopy analysis confirmed effective BC coating of PU fibres without altering BC fibre orientation or bacterial activity.ConclusionBC patches demonstrated burst pressure resistance above 1,400 mmHg. BC's elasticity can be tailored, and in combination with ESP-PU, an innovative hybrid material can be produced, positioning BC as a promising biomaterial for future CCS implant development.

Background:Current heart valve prostheses in congenital cardiac surgery (CCS) are unable to grow, remodel, or adapt to a child's evolving physiology, resulting in increased mortality rates due to material-related limitations. The excellent biocompatibility and hemocompatibility of bacterial cellulose (BC) make it a promising alternative. This study aimed to use BC to develop a biogenic polymer-based heart valve and then to assess its hemodynamic performance and long-term durability. Methods:Heart valve leaflets were produced via a standard BC protocol and compressed to a minimal thickness, and their biomechanical properties were evaluated. Using a customized template, BC leaflets were sutured into a 23-mm stent scaffold. Two prototype series with different leaflet designs were tested in a mock circulatory flow loop model with a flow rate of 5 L/minute at 120/80 mm Hg. Long-term durability was assessed for 10 ± 0.5 million cycles at 120/80 mm Hg, followed by retesting. Results:BC valve leaflets exhibited a thickness reduction of 94.01% to 0.3 ± 0.11 mm (P < .001) while retaining a durability of 100% at 500 mm Hg (n = 23), with a maximum tensile strength of 1.64 ± 0.3 MPa (n = 35). All valves combined (n = 21) displayed a mean transvalvular pressure drop (MTP) of 8.32 ± 1.23 mm Hg, a mean regurgitation fraction (REG) of 10.22 ± 4.42%, and a mean effective orifice area (EOA) of 1.85 ± 0.14 cm2, with valves of series 2 showing a lower REG (P < .001). Following long-term durability testing, all valves of series 2 (n = 6) remained intact, demonstrating an MTP 9.11 ± 1.13 mm Hg, REG of 9.41 ± 4.25%, and EOA of 1.7 ± 0.1 cm2. Conclusions:The potential of BC for use in CCS was demonstrated by developing a new biogenic polymer-based valve with excellent hemodynamic performance. These results warrant further investigation and development of this biomaterial.

There have been few recent innovations since the introduction of cardioplegia more than 50 years ago. Surprisingly, cardioplegia as one of the most essential steps in terms of heart muscle protection during a surgical procedure requiring cardiac arrest has never been really standardized. As a consequence, a considerable variety of cardioplegic solutions and applications have developed: cold versus warm, crystalloid versus blood cardioplegia, antegrade versus retrograde or both, as well as different time schedules for repeated administration. A new cardioplegia solution, called Cardioplexol (TM), has recently received CE marking approval as a drug following two phase III studies. Cardioplexol (TM) shows several advantages: the administration follows a very simple protocol, minimizing the risk of errors in manipulation, and diastolic arrest occurs immediately, thus allowing immediate start of the cardiac work once the aorta has been cross clamped. The very low volume of crystalloid solution (e.g., 100 mL as induction and a second application of 100 mL following 45-60 minutes of ischemia) avoids hemodilution and therefore the need for filtration during surgery. In addition, the injection through the aortic root canula eliminates the need for an additional cardioplegia pump and its disposable tubing system. This simplified cardioplegia that is not inferior to Buckberg solution has the potential for standardization of myocardial protection protocols.