Thierry Carrel

Background: Papillary fibroelastoma, generally affecting the valve endocardium, is one of the most common benign cardiac tumours. Although rarely reported, atypical localization of such tumours complexifies diagnosis and might negatively impact patient outcomes due to late detection. Case summary: We present the case of a 69-year-old female patient presenting for a check-up consultation and reporting symptoms of dysesthesia, aphasia, and dizziness. The patient had a history of atrial fibrillation on anticoagulation with rivaroxaban starting 6 years prior to presentation. Further examination using transthoracic and transoesophageal echocardiography revealed a hyperechogenic structure at the level of the subvalvular apparatus of the mitral valve. Interestingly, when cardiac MRI was subsequently performed, this diagnosis could not be confirmed. This discrepancy might be linked to the lower spatial and temporal resolution compared to transoesophageal echocardiography, or transthoracic echocardiography with a high-frequency probe. To further investigate the symptoms of dysesthesia, aphasia, and dizziness, a cerebral MRI was performed which revealed multiple, bilateral ischaemic lesions. Considering the findings and the symptoms of the patient, the choice was made to perform explorative surgery. Intraoperatively, an 8-mm structure was identified and removed from the basis of the posteromedian papillary muscle. Histological examination revealed a papillary fibroelastoma. The patient was discharged on postoperative day 10. At follow-up, there was no report of neurological symptoms. Discussion: This case shows a highly atypical localization of a rare cardiac tumour and exemplifies the importance of multimodal diagnostic imaging prior to cardiac surgery.

Objectives: Currently available materials in congenital cardiac surgery (CCS) are far from optimal because they do not facilitate growth, remodelling, or renewal, resulting in poorer long-term outcomes due to material-related limitations. Bacterial cellulose (BC), a biogenic polymer-based material produced by Acetobacter xylinum, has emerged as a promising alternative exhibiting excellent bio- and haemocompatibility. This study aimed to develop BC specifically for application in CCS by modifying culturing conditions to enhance its biomechanical resilience. Methods: Bacterial cellulose was produced according to a standard protocol, and its biomechanical properties were evaluated using inflation pressure testing, thickness measurement, and uniaxial tensile testing. To improve these characteristics, 2 modifications, a change in the growth media composition and an extended incubation time, were implemented and subsequently evaluated in 5 further test series. The long-term durability of BC patches was assessed in a fatigue tester for 20 ± 0.5 million cycles, and potential structural damage was investigated using scanning electron microscopy. Results: Utilizing the 2 modifications, BC patches demonstrated a capability to reach and maintain pressures exceeding 1000 mm Hg with a durability of 100% (n = 24), compared to the standard 20.8% (n = 24) at 500 mm Hg. The maximum tensile strength was enhanced from 0.311 ± 0.057 megapascal (MPa) to 0.986 ± 0.397 MPa (P < .0001), with a thickness of 3.89 ± 0.95 mm (P < .0001). In the long-term durability testing, patches endured durations equalling 6 months without failure while retaining structural integrity. Conclusions: The potential of BC for use in CCS was demonstrated by enhancing its biomechanical properties through culturing modifications, warranting further investigation and development of the 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™, has recently received CE marking approval as a drug following two phase III studies. Cardioplexol™ 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.

A sinus of valsalva aneurysm (SVA) is an asymmetrical dilatation of the aortic root located between the aortic valve anulus and the sino-tubular junction. Congenital weakness of the elastic lamina in the aortic media layer or trauma and infection as acquired events are the most principal causes of SVA. Presentation may be acute when rupture has occurred or SVA may be discovered fortuitously on echocardiography or CT scan when patients are examined because of unspecific chest pains, dyspnea or arrhythmias. Although endovascular treatment has been performed successfully in individual cases, surgical closure of the aneurysm aiming at preservation of the aortic valve whenever possible is the established procedure. This short report emphasizes the fact that individual treatment is required when SVA need to be operated, depending on the presentation, the location and the size of the finding. Surgery may consist of simple patch closure, bilateral tunnel closure (entry and exit) or more radical operation like Bentall in case the whole aortic root should be addressed. Overall results are excellent, independently of the clinical presentation (acute or elective) with a mortality approaching zero.

We propose an evolution of a dielectric elastomer actuator-based cardiac assist device that acts as a counterpulsation system. We introduce a new pre-stretched actuator and implant the device in a graft bypass between the ascending and descending aorta to redirect all blood through the device (ascending aorta clamped). The objective was to evaluate the influence of these changes on the assistance provided to the heart. The novel para-aortic device and the new implantation technique were tested in vivo in 5 pigs. We monitored the pressure and flow in the aorta as well as the pressure–volume characteristics of the left ventricle. Different activation timings were tested to identify the optimal device actuation. The proposed device helps reducing the end-diastolic pressure in the aorta by up to 13 ± 4.0% as well as the peak systolic pressure by up to 16 ± 3.6%. The early diastolic pressure was also increased up to 10 ± 3.5%. With different activation, we also showed that the device could increase or decrease the stroke volume. The new setup and the novel para-aortic device presented here helped improve cardiac assistance compared to previous studies. Moreover, we revealed a new way to assist the heart by actuating the device at different starting time to modify the left ventricular stroke volume and stroke work.

The aortic valve is the most frequently diseased valve and aortic stenosis (AS) is the most prevalent valvular heart disease in developed countries. The diseased native aortic valve can be replaced by either a biological or mechanical valve prosthesis. The main concerns relate to durability, the need for oral anticoagulants and the incidence of complications related to this medication. Experimental, computational and biomolecular blood flow studies have demonstrated that the systolic forward flow but also the reverse flow phase at the end of the systole and leakage during the diastolic phase is mainly responsible for platelet activation and thrombosis. Better design of mechanical prosthetic heart valves must ensure smooth closing during flow deceleration and must eliminate high-shear hinge flow during diastole to prevent life-threatening thrombosis. A novel tri-leaflet valve should combine the favorable hemodynamics and the durability of existing mechanical heart valves and eliminate the less favorable characteristics, including the extremely rapid closing. In this paper, we discuss some issues of current mechanical heart valve prostheses and present a new valve design with the potential for significant innovation in the field. The TRIFLO Heart Valve, is a rigid, three-leaflet central flow heart valve prosthesis consisting of an alloyed titanium housing, and three rigid polymer (PEEK) cusps. This valve has a physiological operating mode. During the forward flow phase, the intraventricular pressure opens the leaflets so that blood can freely flow through with little obstruction, and with the deceleration of the blood flow, the leaflets close early and smoothly, minimizing blood flow regurgitation, blood cell damage, and activation of the coagulation cascade. Pre-clinical studies have shown pretty favorable results and a first-in-man study should start very soon.