Hemodynamic Assessment in Bicuspid Aortic Valve Disease and Aortic Dilation: New Insights From Voxel-By-Voxel Analysis of Reverse Flow, Stasis, and Energetics

Objectives: Clinical management decisions surrounding ascending aorta (AAo) dilation in bicuspid aortic valve (BAV) disease benefit from personalized predictive tools. 4D-flow MRI may provide patient-specific markers reflective of BAV-associated aortopathy. This study aims to explore novel 4D-flow MRI parametric voxel-by-voxel forward flow, reverse flow, kinetic energy and stasis in BAV disease. We hypothesize that novel parametric voxel-by-voxel markers will be associated with aortic dilation and referral for surgery and can enhance our understanding of BAV hemodynamics beyond standard metrics.Methods: A total of 96 subjects (73 BAV patients, 23 healthy controls) underwent MRI scan. Healthy controls had no known cardiovascular disease. Patients were clinically referred for AAo dilation assessment. Indexed diameters were obtained by dividing the aortic diameter by the patient’s body surface area. Patients were followed for the occurrence of aortic surgery. 4D-flow analysis was performed by a single observer in five regions: left ventricular outflow tract (LVOT), AAo, arch, proximal descending aorta (PDAo), and distal descending aorta (DDAo). In each region peak velocity, kinetic energy (KE), forward flow (FF), reverse flow (RF), and stasis were measured on a voxel-by-voxel basis. T-tests (or non-parametric equivalent) compared flow parameters between cohorts. Univariate and multivariate analyses explored associations between diameter and parametric voxel-by-voxel parameters.Results: Compared to controls, BAV patients showed reduced stasis (p < 0.01) and increased RF and FF (p < 0.01) throughout the aorta, and KE remained similar. In the AAo, indexed diameter correlated with age (R = 0.326, p = 0.01), FF (R = −0.648, p < 0.001), RF (R = −0.441, p < 0.001), and stasis (R = −0.288, p < 0.05). In multivariate analysis, FF showed a significant inverse association with AAo indexed diameter, independent of age. During a median 179 ± 180 days of follow-up, 23 patients (32%) required aortic surgery. Compared to patients not requiring surgery, they showed increased KE and peak velocity in the proximal aorta (p < 0.01), accompanied by increased RF and reduced stasis throughout the entire aorta (p < 0.01).Conclusion: Novel voxel-by-voxel reverse flow and stasis were altered in BAV patients and are associated with aortic dilation and surgical treatment.

Morphometric Analysis of the Aorto-Esophageal Relationship in Swine for Trans-Esophageal Aortic Blood Flow Occlusion

Background Trans-esophageal aortic blood flow occlusion (TEABO) is an emerging technology undergoing laboratory research that offers a strategy for temporary hemorrhage control. The purpose of this study was to evaluate the anatomical relationship between the esophagus and descending thoracic aorta in two breeds of swine to support a porcine model for future TEABO investigations. Methods Thoracoabdominal CT scans were compared in Hanford miniature swine and Yorkshire swine. Measurements were taken at the five vertebral levels proximal to the gastroesophageal junction. Data collected included the distance between the center of the esophagus and the center of the descending aorta, the angle between the vertebral column, descending aorta, and esophagus, and the length the thoracic esophagus travels anteriorly to the descending aorta. Results Ten Hanford swine and ten Yorkshire swine were compared. In Hanford swine, the distal thoracic esophagus travels anteriorly to the descending aorta for a mean distance of 11.5 ± 2.3 cm. In Yorkshire swine, the thoracic esophagus travels to the right of the descending aorta. The mean angle between the vertebral body, descending aorta, and esophagus was 79.6 to 97.8 degrees higher in Hanfords compared to Yorkshires (p<0.0001 at all five vertebral levels compared). The mean distance between the esophagus and descending aorta was 0.2 to 0.6 cm higher in Hanfords compared to Yorkshires with a significant difference found at only two vertebral levels (p=0.01 and p=0.02). Conclusion Hanford miniature swine possess an aorto-esophageal relationship comparable to humans and should be the preferred animal model for TEABO studies.

Retrieving a lost needle in the descending aorta during hemi-arch replacement

A 73-year-old man diagnosed with moderate aortic insufficiency and dilatation of the aortic root and ascending aorta underwent a modified Bentall procedure and hemi-arch aortic replacement. During open distal anastomosis of the ascending aorta, the surgical needle was lost. Because of circulatory arrest, the operation was continued; before closing the chest, radiography and a transesophageal echo were located in the needle in the descending aorta. It was retrieved using a snare catheter via the graft branch under fluoroscopic guidance. Thus, locating the needle in the descending aorta and leaving the graft branch uncut led to its removal without a new incision.

Impact of fetal haemodynamics on surgical and neurodevelopmental outcomes in patients with Ebstein anomaly and tricuspid valve dysplasia

Objectives: To evaluate the impact of fetal haemodynamics on surgical and neurodevelopmental outcomes in severe Ebstein anomaly and tricuspid valve dysplasia. Methods: Thirty-four fetuses with Ebstein anomaly/tricuspid valve dysplasia were referred from 2013 to 2019 for fetal echocardiography and clinical management. Nineteen fetuses with Ebstein anomaly/tricuspid valve dysplasia and 30 controls underwent cardiovascular magnetic resonance to quantify the fetal blood flow and to calculate cerebral oxygen delivery (cDO2) and consumption (cVO2). The 3D steady-state free precession acquisition was used to measure fetal brain volume. Surgical outcome, brain MRI, and neurodevelopmental follow-up were reviewed. Results: Twenty-six fetuses were live born (76%) and survival (65%) at a mean follow-up of 4 years. Nine fetuses had a brain MRI before discharge, and all had clinically silent injuries and volume loss. At 18 months, five single-ventricle patients had a neurodevelopmental delay in cognition and language (mean percentile: 11th), with gross-motor skills more affected than fine-motor skills (mean percentiles: 4th and 34th). Fetuses with Ebstein anomaly/tricuspid valve dysplasia had smaller brains, lower combined ventricular output, ascending aorta, superior caval vien and umbilical vein flows, lower oxygen saturation in ascending aorta and superior caval vien, lower cDO2 and cVO2 (p < 0.05). Superior caval vien/combined ventricular output and descending aorta/combined ventricular output ratios were lower in fetuses with circular shunt (p < 0.05). Fetuses requiring the Starnes procedure tended to have smaller brains, lower combined ventricular output, superior caval vien, descending aorta, and umbilical vein flows. Conclusions: All patients with Ebstein anomaly/tricuspid valve dysplasia are at high risk of neurodevelopmental delay and warrant follow-up. Fetal cardiovascular magnetic resonance revealed impaired brain growth with diminished cerebral blood flow and cDO2, the extenting dependent on the severity of the haemodynamic compromise.

Assessment of Asymptomatic Severe Aortic Regurgitation by Doppler-Derived Echo Indices: Comparison with Magnetic Resonance Quantification

Reliable quantification of aortic regurgitation (AR) severity is essential for clinical management. We aimed to compare quantitative and indirect echo-Doppler indices to quantitative cardiac magnetic resonance (CMR) parameters in asymptomatic chronic severe AR. Methods and Results: We evaluated 104 consecutive patients using echocardiography and CMR. A comprehensive 2D, 3D, and Doppler echocardiography was performed. The CMR was used to quantify regurgitation fraction (RF) and volume (RV) using the phase-contrast velocity mapping technique. Concordant grading of AR severity with both techniques was observed in 77 (74%) patients. Correlation between RV and RF as assessed by echocardiography and CMR was relatively good (rs = 0.50 for RV, rs = 0.40 for RF, p < 0.0001). The best correlation between indirect echo-Doppler and CMR parameters was found for diastolic flow reversal (DFR) velocity in descending aorta (rs = 0.62 for RV, rs = 0.50 for RF, p < 0.0001) and 3D vena contracta area (VCA) (rs = 0.48 for RV, rs = 0.38 for RF, p < 0.0001). Using receiver operating characteristic analysis, the largest area under curve (AUC) to predict severe AR by CMR RV was observed for DFR velocity (AUC = 0.79). DFR velocity of 19.5 cm/s provided 78% sensitivity and 80% specificity. The AUC for 3D VCA to predict severe AR by CMR RV was 0.73, with optimal cut-off of 26 mm2 (sensitivity 80% and specificity 66%). Conclusions: Out of the indirect echo-Doppler indices of AR severity, DFR velocity in descending aorta and 3D vena contracta area showed the best correlation with CMR-derived RV and RF in patients with chronic severe AR.

Fate of the Dissected Thoraco-Abdominal Aorta Distal to TEVAR (Thoracic Endovascular Aortic Repair) for Complicated Acute and Subacute Type B Aortic Dissection

Purpose: This study assessed morphological changes in the aortic true and false lumens during follow-up of patients undergoing TEVAR (Thoracic Endovascular Aortic Repair) for complicated acute and subacute type B dissection. The study analyzes the effectiveness of TEVAR in preventing distal aneurysmal progression. Materials and Methods: All patients between 2009 and 2019 undergoing TEVAR for complicated acute and subacute type B dissection at the study institution were retrospectively reviewed. Maximal diameters were measured on the proximal descending aorta right below the left subclavian artery, thoraco-abdominal junction right above the celiac trunk, and infrarenal aortic right above the inferior mesenteric artery, pre-operatively and during follow-up, analyzing either expansion or shrinkage of true and false lumens at these 3 sites. Results: Forty-one patients were included. Thirty-day incidence of death, stroke, paraplegia, and visceral ischemia was, respectively, 8% (n = 4), 6% (n = 3), 2% (n = 1), and 2% (n = 1). Three patients (6%) died from intervention-related cause. Mortality was 17% (n = 8) during a mean follow-up of 54 months. One patient had aneurysmal dilation of the descending aorta needing additional coverage and only 2 (4%) developed thoraco-abdominal aneurysms requiring re-intervention. In the remaining patients, both significant expansion of the true lumen and shrinkage of false lumen were observed at all 3 sites. Conclusion: Proximal coverage of the main entry tear appears to prevent aneurysmal progression in most patients (96%). With such promising results, TEVAR should be considered as a first-line treatment in acute and subacute type B dissection.

Giant Aortic Aneurysm in Child with Cutis Laxa Syndrome: Unusual Presentation, New Surgical Technique

Ascending thoracic aortic aneurysms are rare in childhood and typically are seen in the setting of connective tissue defect syndromes. These aneurysms may lead to rupture, dissection, or valvular insufficiency, so root replacement is recommended. Here, we present a 17-month-old girl who presented with fever, cough, and pericardial effusion. Initially, we suspected this could be a COVID-19 case, so a nasopharyngeal swap was performed. An ascending aorta aneurysm involving the aortic arch was confirmed by echo, and urgent ascending aorta and arch replacement were done by utilizing the descending aorta as a new arch. The final diagnosis came with cutis laxa syndrome. In similar cases, good outcomes can be achieved with accurate diagnosis and appropriate surgical management.

Transapical cannulation for surgical repair of chronic type B aortic dissection

Open surgery for chronic type B aortic dissection has been shown to have considerable risks of cerebrovascular complications. Because retrograde perfusion is a potential cause of intraoperative cerebrovascular events, we report our transapical cannulation strategy for descending aorta replacement in chronic type B aortic dissection repair with circulatory arrest. This technique provides an easy and quick establishment of cardiopulmonary bypass by way of a left thoracotomy, and prevention of cerebrovascular event. Transapical cannula can be also used as a vent to ensure a bloodless field during proximal anastomosis and to prevent extension of left ventricle during rewarming. Transapical cannulation is a useful option in open repair of the descending aorta for chronic type B aortic dissection by way of left thoracotomy.