Flow Characteristics by Blood Speckle Imaging in Non-Stenotic Congenital Aortic Root Disease Surrounding Valve-Preserving Operations

TL;DR

This study shows that blood speckle imaging improves understanding of blood flow after aortic valve-preserving surgeries in congenital heart disease patients.

Contribution

Demonstrates the novel use of blood speckle imaging to assess flow dynamics in non-stenotic congenital aortic root disease post-surgery.

Findings

Post-operative BSI revealed improved hemodynamics with reduced oscillatory shear index and increased wall shear stress.

Valve-preserving operations led to rectified asymmetric jets and reversed flow in the ascending aorta.

Hemodynamic improvements were observed beyond conventional echocardiographic assessments.

Abstract

Contemporary evaluation and surgical approaches in congenital aortic valve disease have yielded limited success. The ability to evaluate and understand detailed flow characteristics surrounding surgical repair may be beneficial. This study explores the feasibility and utility of echocardiographic-based blood speckle imaging (BSI) in assessing pre- and post-operative flow characteristics in those with non-stenotic congenital aortic root disease undergoing aortic valve repair or valve-sparing root replacement (VSRR) surgery. Transesophageal echocardiogram was performed during the pre-operative and post-operative assessment surrounding aortic surgery for ten patients with non-stenotic congenital aortic root disease. BSI, utilizing block-matching algorithms, enabled detailed visualization and quantification of flow parameters from the echocardiographic data. Post-operative BSI unveiled enhanced hemodynamic patterns, characterized by quantified changes suggestive of the absence of stenosis and no more than trivial regurgitation. Rectification of an asymmetric jet and the reversal of flow on the posterior aspect of the ascending aorta resulted in a reduced oscillatory shear index (OSI) of 0.0543±0.0207 (pre-op) vs. 0.0275±0.0159 (post-op) and p=0.0044, increased peak wall shear stress of 1.9423±0.6974 (pre-op) vs. 3.6956±1.4934 (post-op) and p=0.0035, and increased time-averaged wall shear stress of 0.6885±0.8004 (pre-op) vs. 0.8312±0.303 (post-op) and p=0.23. This correction potentially attenuates cellular alterations within the endothelium. This study demonstrates that children and young adults with non-stenotic congenital aortic root disease undergoing valve-preserving operations experience significant improvements in flow dynamics within the left ventricular outflow tract and aortic root, accompanied by a reduction in OSI. These hemodynamic enhancements extend beyond the conventional echocardiographic assessments, offering immediate and valuable insights into the efficacy of surgical interventions.

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