Aortic root replacement in severe left ventricular dysfunction: The added value of beating-heart surgery.

There are limits to the use of cardioplegic arrest during complex cardiac surgical procedures, especially in patients with severe left ventricular dysfunction. In the current report, we graphically present the detailed surgical strategy and technique for beating-heart aortic root replacement with concomitant coronary bypass grafting, for patients otherwise deemed inoperable. With support of cardiopulmonary bypass (CPB), beating-heart bypass surgery is realized, after which the bypass grafts can selectively be connected to the CPB, preserving coronary flow. Then, on the beating and perfused heart, a complex procedure such as aortic root replacement can be performed, without jeopardizing postoperative cardiac function. However, several important caveats and remarks regarding the use of beating-heart surgery should be considered, including: coronary perfusion verification and maintenance, temperature management, and prevention of air embolisms. By use of this strategy, risks associated with cardioplegic arrest are minimized, while it circumvents the potential need for long-term postoperative extracorporeal membrane oxygenation.

Intra-Operative Video-Based Measurement of Biaxial Strains of the Ascending Thoracic Aorta.

Local biaxial deformation measurements are essential for the in-depth investigation of tissue properties and remodeling of the ascending thoracic aorta, particularly in aneurysm formation. Current clinical imaging modalities pose limitations around the resolution and tracking of anatomical markers. We evaluated a new intra-operative video-based method to assess local biaxial strains of the ascending thoracic aorta. In 30 patients undergoing open-chest surgery, we obtained repeated biaxial strain measurements, at low- and high-pressure conditions. Precision was very acceptable, with coefficients of variation for biaxial strains remaining below 20%. With our four-marker arrangement, we were able to detect significant local differences in the longitudinal strain as well as in circumferential strain. Overall, the magnitude of strains we obtained (range: 0.02-0.05) was in line with previous reports using other modalities. The proposed method enables the assessment of local aortic biaxial strains and may enable new, clinically informed mechanistic studies using biomechanical modeling as well as mechanobiological profiling.