Blood flow patterns and pressure loss in the ascending aorta: A comparative study on physiological and aneurysmal conditions.

An aortic aneurysm is defined as a balloon-shaped bulging of all three histologic components of the aortic vessel walls (intima, media and adventitia). This dilation results from vessel weakening owing to remodeling, i.e. due to cystic degeneration of the Tunica media (Marfan), progression of atherosclerosis or presence of a bicuspid aortic valve. The growth rate of the aortic diameter varies from patient to patient and may progress until the aneurysm ultimately ruptures. The role of hemodynamics, i.e. blood flow patterns, and shear stresses that are supposed to intensify during aneurysm growth are not yet fully understood, but thought to play a key role in the enlargement process. The aim of this study is to characterize the aortic blood flow in a silicone model of a pathological aorta with ascending aneurysm, to analyze the differences in the blood flow pattern compared to a healthy aortic model, and to single out possible blood flow characteristics measurable using phase contrast magnetic resonance imaging (MRI) that could serve as indicators for aneurysm severity. MRI simulations were performed under physiological, pulsatile flow conditions using data obtained from optical three dimensional particle tracking measurements. In comparison to the healthy geometry, elevated turbulence intensity and pressure loss are measured in the diseased aorta, which we propose as a complimentary indicator for assessing the aneurysmal severity. Our results shed a light on the interplay between the blood flow dynamics and their contribution to the pathophysiology and possible role for future risk assessment of ascending aortic aneurysms.

How to Treat Tricuspid Valve Disease: What's New on the Horizon?

OPINION STATEMENT: Tricuspid regurgitation is frequent and is most often caused by annular dilatation and leaflet tethering from adverse right ventricular remodeling in response to several disease processes (functional tricuspid regurgitation), while primary/organic tricuspid valve regurgitation is less common. Surgical intervention for tricuspid regurgitation is usually performed concomitantly to left-sided heart valve surgery. In isolated significant tricuspid regurgitation, however, many patients are left unoperated as they commonly are considered at very high or prohibitive surgical risk. Moreover, the risk versus benefit data are not as well-established as compared to other valve disease. Multiple novel transcatheter therapies have now begun to emerge with the aim to treat tricuspid regurgitation less invasively. For most new interventional procedures, current trials are designed to prove efficacy and safety. In the foreseeable future, however, patients with significant MR can likely be offered a multifaceted palette of minimally invasive transcatheter options in addition to conventional surgery, which will allow to treat more patients in need. These current developments make tricuspid valve disease and its therapy an exciting field of study.

Management of Tricuspid Regurgitation: The Role of Transcatheter Therapies.

Surgical treatment is the gold standard treatment of functional tricuspid regurgitation (FTR) but this carries high risks of morbidity and mortality. Percutaneous procedures are an attractive alternative to surgery for selected patients deemed to be high-risk surgical candidates. A number of tricuspid transcatheter devices have been developed to treat FTR, but at present, evidence of their efficacy and safety is scarce. Preliminary data have shown promising results, but ongoing and future studies will provide a clearer picture of the benefits of these new techniques.