scholarly journals Hemodynamic Characteristics of Dilated Ascending Aorta in Patients with Bicuspid Aortic Valve

Author(s):  
Tie Zheng ◽  
Shijie Lu ◽  
Shuai Zhu ◽  
Jiafu Ou ◽  
Jun-Ming Zhu

Abstract Objective: Aim of this study is to investigate the influence of aortic diameter on hemodynamic environment characteristics in patient with the bicuspid aortic valve (BAV) and dilated ascending aorta (AAo) .Methods: In this study, an MRI of one BAV patient with 4.5 cm AAo was collected and numerical model was constructed. Based on the images,the other three numerical models were constructed with different ascending aortic size with 4.0cm, 5.0cm and 5.5cm respectively while the size and the geometry of other parts were fixed. Then hemodynamics in these four models was simulated numerically and the flow patterns and loading distributions were investigated.Results: Hemodynamics environments in the AAo were simulated with different aortic size. As the aortic diameter increases, we find: 1. the blood flow becomes more disturbing;2.the wall pressure at ascending aortic is higher; 3. the wall shear stress at the ascending aortic decreases; 4.oscillatory shear index of the outer part on the proximal AAo increases;5. all these hemodynamic parameters described above are asymmetrically distributed in dilated AAo and more parts of aorta would be affected as the AAo dilatation progresses.Conclusions: The study revealed that the diameter of ascending aortic can significantly influence the magnitude and distribution of the dynamics. There are altered flow patterns, pressure difference, WSS and OSI distribution features in bicuspid aortic valve patients with vascular dilatation. As the extent of aortic dilatation increases especially exceed 5.5cm,this study support the recent guideline that aortic replacement should be considered .

2020 ◽  
Author(s):  
Tie Zheng ◽  
Shuai Zhu ◽  
Shijie Lu ◽  
Jiafu Ou ◽  
Jun-Ming Zhu

Abstract Background: The bicuspid aortic valve is one of the common congenital heart anomalies in adults. Although many studies have proved the coincidence between bicuspid aortic valve and the occurrence of ascending aortic dilation, seldom study has focused on the hemodynamic environments after the dilation already formed. Four numerical models of bicuspid aortic valve were constructed in this study, based on medical images, with different ascending aortic dilation levels. The diameters of ascending aortic are 3.5cm, 4.0cm, 4.5cm and 5.0cm, respectively; while, the size and the geometry of other parts are fixed. Then hemodynamics in these models was simulated numerically and the flow patterns and loading distributions were investigated. Aim of this study is to investigate the hemodynamic environment characteristics in the ascending aorta after dilation formed for the bicuspid aortic valve (BAV) patients. Results: Hemodynamics environments in the dilated ascending aorta were simulated, with different level of dilation. As the diameter increases, the blood flow becomes more disturbing. The wall shear stress at the ascending aortic decreases while oscillatory shear index increases with the increase of diameter. The pressure at ascending aortic increases as the diameter increases. Moreover, all these hemodynamic parameters described above are asymmetrically distributed with the increase of ascending aortic diameter and more parts of aorta would be affected with the increasing ascending aorta diametersConclusions: The study revealed that the ascending aortic dilation levels can significantly influence the magnificent and distribution of the dynamics. There are altered flow patterns, pressure difference, WSS and OSI distribution features in bicuspid aortic valve patients with valvular dilation. As the extent of aortic dilatation increases, more parts of aorta like aortic arch should be paid more attention to when an individual is referred for surgery


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
G Goudot ◽  
T Mirault ◽  
C Cheng ◽  
M Gruest ◽  
J Amoah ◽  
...  

Abstract Background Magnetic resonance imaging allows evaluation of aortic stiffness by the maximum rate of systolic distension (MRSD) a new prognosis factor of aortic dilatation in patients with bicuspid aortic valve (BAV). MRSD requires a continuous monitoring of the aortic diameter during the cardiac cycle, not accessible to conventional echocardiography contrary to ultrafast ultrasound imaging (UF). Purpose To develop specific aortic sequences in ultrafast ultrasound imaging (UF) to provide access to the aortic MRSD Methods Tissue Doppler allowed a precise estimation of the movement of each wall and the fine variation of the aortic diameter. To automatically track the anterior and posterior aortic walls during the cardiac cycle, we developed in the laboratory a specific interface (Figure). MRSD was the maximum of the derivative of the diameter chande over time. To assess this new technique, 24 patients (10 BAV patients and 14 controls, mean age 45.8 vs. 40.7 years, p=0.464, respectively) were consecutively included at a reference center for BAV. The ascending aorta was evaluated at the sinus of Valsalva, the tubular aorta and the aortic arch with a phased array probe (Supersonic Imagine) and dedicated sequences at 2000 frames/s. Results The lab-made interface allowed to track the aortic diameter and to calculate the MRSD from the UF acquisitions for each patient. We found lower MRSD at the sinus of Valsalva in case of BAV in accordance with previously demonstrated higher stiffness at this segment by our team (Table). Table 1. UF Aortic parameters for BAV patients and controls BAV patients Controls p (Mann Whitney) Sinus of Valsalva Diameter (mm) 26.2 [22.4–32.5] 27.09 [23.5–29.5] 0.796 MRSD (s–1) 1.05 [0.73–1.19] 1.51 [1.28–1.99] 0.023 Tubular ascending aorta Diameter 31.4 [29.4–32.2] 28.9 [22.6–31.5] 0.328 MRSD 0.94 [0.59–1.27] 1.09 [0.87–1.41] 0.353 Aortic arch Diameter 24.2 [23.7–24.8] 24.2 [18.9–24.5] 0.673 MRSD 0.57 [0.35–1.07] 0.85 [0.76–1.02] 0.257 Results are median [25th–75th percentile]. Figure 1 Conclusion UF allows evaluation of aortic stiffness by MRSD using dedicated sequence and interface. As echocardiography, UF is easily accessible and therefore deserves attention from cardiologists taking care of BAV patients to evaluate the segmental aortic remodeling associated with BAV.


2020 ◽  
Vol 9 (2) ◽  
pp. 290
Author(s):  
Anthonie Duijnhouwer ◽  
Allard van den Hoven ◽  
Remy Merkx ◽  
Michiel Schokking ◽  
Roland van Kimmenade ◽  
...  

Objective: The combination of aortic coarctation (CoA) and bicuspid aortic valve (BAV) is assumed to be associated with a higher risk of ascending aortic dilatation and type A dissection, and current European Society of Cardiology (ESC) guidelines advise therefore to operate at a lower threshold in the presence of CoA. The aim of our study is to evaluate whether the coexistence of CoA in BAV patients is indeed associated with a higher risk of ascending aortic events (AAE). Methods: In a retrospective study, all adult BAV patients visiting the outpatient clinic of our tertiary care center between February 2003 and February 2019 were included. The primary end point was an ascending aortic event (AAE) defined as ascending aortic dissection/rupture or preventive surgery. The secondary end points were aortic dilatation and aortic growth. Results: In total, 499 BAV patients (43.7% female, age 40.3 ± 15.7 years) were included, of which 121 (24%) had a history of CoA (cBAV). An aortic event occurred in 38 (7.6%) patients at a mean age of 49.0 ± 13.6 years. In the isolated BAV group (iBAV), significantly more AAE occurred, but this was mainly driven by aortic valve dysfunction as indication for aortic surgery. There was no significant difference in the occurrence of dissection or severely dilated ascending aorta (>50 mm) between the iBAV and cBAV patients (p = 0.56). The aortic diameter was significantly smaller in the cBAV group (30.3 ± 6.9 mm versus 35.7 ± 7.6 mm; p < 0.001). The median aortic diameter increase was 0.23 (interquartile range (IQR): 0.0–0.67) mm/year and was not significantly different between both groups (p = 0.74). Conclusion: Coexistence of CoA in BAV patients was not associated with a higher risk of aortic dissection, preventive aortic surgery, aortic dilatation, or more rapid aorta growth. This study suggests that CoA is not a risk factor in BAV patients, and the advice to operate at lower diameter should be reevaluated.


2021 ◽  
Vol 8 ◽  
Author(s):  
Daniel G. W. Cave ◽  
Hannah Panayiotou ◽  
Malenka M. Bissell

Bicuspid aortic valve (BAV) disease presents a unique management challenge both pre- and post-operatively. 4D flow MRI offers multiple tools for the assessment of the thoracic aorta in aortic valve disease. In particular, its assessment of flow patterns and wall shear stress have led to new understandings around the mechanisms of aneurysm development in BAV disease. Novel parameters have now been developed that have the potential to predict pathological aortic dilatation and may help to risk stratify BAV patients in future. This systematic review analyses the current 4D flow MRI literature after aortic valve and/or ascending aortic replacement in bicuspid aortic valve disease. 4D flow MRI has also identified distinct challenges posed by this cohort at the time of valve replacement compared to standard management of tri-leaflet disorders, and may help tailor the type and timing of replacement. Eccentric pathological flow patterns seen after bioprosthetic valve implantation, but not with mechanical prostheses, might be an important future consideration in intervention planning. 4D flow MRI also has promising potential in supporting the development of artificial valve prostheses and aortic conduits with more physiological flow patterns.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Ayyaz Ali ◽  
Amit Patel ◽  
Darren Freed ◽  
Yasir Abu-Omar ◽  
Ahmad Y Sheikh ◽  
...  

Objectives A bicuspid aortic valve may be associated with an aortopathy, this may lead to progressive aortic dilatation over time. It is uncertain whether the ascending aorta should be replaced prophylactically during AVR in these patients. We analyzed change in ascending aortic diameter following AVR, to determine whether a clinically important aortic pathology exists in patients with bicuspid aortic valve disease. Methods Demographic, operative and clinical data were obtained retrospectively through casenote review. AVR was performed using a homograft or porcine stentless valve using the subcoronary implantation technique. Patients were grouped according to whether their native aortic valve was identified as tricuspid (TC) or bicuspid (BC) at operation. Serial transthoracic echocardiograms were analyzed to measure pre-operative and post-operative ascending aortic diameter. Results 217 patients underwent AVR between 1 st January 1991 and 1 st January 2001. Ninety patients had a bicuspid aortic valve, in the remaining 127 the valve was tricuspid. The bicuspid group was younger ( BC 62yr +/− 15, TC 71yr +/− 12 yrs; p < 0.001). Follow-up echocardiography was performed 6.0 +/− 4.3 years post-operatively. Pre-operative ascending aortic diameter was similar (BC 3.2 +/− 0.5, TC 3.2 +/− 0.5 cm; p = 0.56) There was no difference in the increase in ascending aortic diameter over follow-up (BC 0.1 +/− 0.5, TC 0.0 +/− 0.5 cm; p = 0.34) Conclusion The clinical importance of “bicuspid aortopathy” in an older age group appears to be minimal. Additional aortic procedures designed to protect against progressive aortic aneurysmal disease in this setting are not justified.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Vandana Sachdev ◽  
Lea Ann Matura ◽  
Stanislav Sidenko ◽  
Vincent Ho ◽  
Andrew Arai ◽  
...  

Women with Turner syndrome (TS) have an increased risk of congenital cardiovascular defects. Previous studies have reported a 10 –20% prevalence rate of bicuspid aortic valves and there are increasing reports of a vasculopathy that predisposes patients to aortic dilatation and dissection. This prospective study aimed to characterize aortic valve and aortic root structure in unselected asymptomatic individuals with TS. A total of 253 females aged 7– 67 years with karyotype proven TS were examined. Transthoracic echocardiography revealed a normal tricuspid aortic valve (TAV) in 162, a ‘probable TAV’ in 8 subjects, a bicuspid aortic valve (BAV) in 65 and ‘probable BAV’ in 3 subjects. The aortic valve could not be visualized by echocardiography in 15/253 or 6%. Magnetic resonance imaging (MRI) revealed valve structure in 11/12 of the probable cases (all confirmatory of the ‘probable’ diagnosis) and 12/15 of the non-visualized cases (8 BAV and 4 TAV), so only 3/253 subjects could not be visualized by either modality. The aortic valve was bicuspid in 76 of the 250 adequately imaged subjects (30%). Peak aortic valve flow was higher in BAV subjects (1.72±0.07 vs. 1.90v0.03 m/sec, P=0.0002), with one case of significant aortic stenosis. Among subjects with a BAV, aortic regurgitation was moderate or greater in ∼15%. Aortic diameters at the annulus, sinuses of Valsalva, sinotubular junction and ascending aorta were all significantly greater in the BAV group. Thirty patients in the BAV group (12%) had aortic root diameters that were outside of the 95% normal confidence limits based on Roman nomograms. Ascending aortic diameters by echo and MRI were highly correlated (r=0.77). In summary, echocardiography supplemented with MRI reveals an extraordinarily high prevalence of abnormal aortic valves in asymptomatic subjects with TS. The abnormal valve structure is associated with higher peak flows, evidence of clinically significant valvular dysfunction, and widening of the ascending aorta in a significant number of patients. All girls and women with TS should have careful echocardiographic evaluation upon diagnosis to identify the one in three asymptomatic individuals with an abnormal valve requiring monitoring for aortic root dilatation and valvular dysfunction.


2020 ◽  
pp. 021849232092873
Author(s):  
Dimitrios C Iliopoulos ◽  
Dimitrios P Sokolis

Bicuspid aortic valve is the most common congenital cardiovascular defect, often associated with proximal aortic dilatation, and the ideal management strategy is debated. The inconsistency in previous and present guideline recommendations emphasizes the insufficiency of the maximal diameter as the sole criterion for prophylactic repair. Our ability to guide clinical decisions may improve through an understanding of the mechanical properties of ascending thoracic aortic aneurysms in bicuspid compared to tricuspid aortic valve patients and non-aneurysmal aortas, because dissection and rupture are aortic wall mechanical failures. Such an understanding of the mechanical properties has been attempted by several authors, and this article addresses whether there is a controversy in the accumulated knowledge. The available mechanical studies are briefly reviewed, discussing factors such as age, sex, and the region of mechanical examination that may be responsible for the lack of unanimity in the reported findings. The rationale for acquiring layer-specific properties is presented along with the main results from our recent study. No mechanical vulnerability of ascending thoracic aortic aneurysms was evidenced in bicuspid aortic valve patients, corroborating present conservative guidelines concerning the management of bicuspid aortopathy. Weakening and additional vulnerability was evidenced in aged patients and those with coexisting valve pathology, aortic root dilatation, hypertension, and hyperlipidemia. Discussion of these results from age- and sex-matched subjects, accounting for the region- and layer-specific aortic heterogeneity, in relation to intact wall results and histologic confirmation, helps to reconcile previous findings and affords a universal interpretation of ascending aorta mechanics in bicuspid aortopathy.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Wang ◽  
Wenhui Deng ◽  
Qing Lv ◽  
Yuman Li ◽  
Tianshu Liu ◽  
...  

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality. BAV aortic dilatation is associated with an increased risk of adverse aortic events and represents a potentially lethal disease and hence a considerable medical burden. BAV with aortic dilatation warrants frequent monitoring, and elective surgical intervention is the only effective method to prevent dissection or rupture. The predictive value of the aortic diameter is known to be limited. The aortic diameter is presently still the main reference standard for surgical intervention owing to the lack of a comprehensive understanding of BAV aortopathy progression. This article provides a brief comprehensive review of the current knowledge on BAV aortopathy regarding clinical definitions, epidemiology, natural course, and pathophysiology, as well as hemodynamic and clinically significant aspects on the basis of the limited data available.


2020 ◽  
Vol 23 (4) ◽  
pp. E435-E440
Author(s):  
Fei Li ◽  
Qi Gao ◽  
En Qiao ◽  
Gang Yin ◽  
Ru-Jiao Zhang ◽  
...  

Purpose: The dilation of proximal arch (PArc) was suspected to develop as a result of valve-related hemodynamics or in consequence to the upward extension of the ascending aorta (AAo) dilation. We aimed to investigate the one that could be the possible contributing factor in patients with bicuspid aortic valve (BAV). Methods: All enrolled BAV patients underwent four-dimensional flow magnetic resonance imaging. Contour-averaged circumferential wall shear stress (WSScirc,avg) and the diameter of the middle of AAo (mid-AAo) were compared between the patients with and without PArc dilation. Additionally, we analyzed the correlation between WSScirc,avg and aortic diameter at PArc section, as well as the correlation between the diameter of mid-AAo and that of PArc. Results: No significant difference was observed in WSScirc,avg at PArc section between the patients with and without PArc dilation (P = .621). However, the diameter of mid-AAo in the patients who suffered PArc dilation was higher than those without it (P = .007). In addition, the aortic diameter did not correlate with the WSScirc,avg at PArc level (R = -0.068, P = .701). The correlation was observed between PArc diameter and mid-AAo diameter (R = 0.521, P = .002). Conclusion: Hemodynamics may not contribute to the development of PArc dilation. PArc diameter correlated with mid-AAo diameter, indicating PArc dilation may be secondary to the upward extension of AAo dilation. The influence of AAo dilation extending upward could be treated by AAo replacement; hence, a selective approach to transverse PArc replacement might be appropriate.


Sign in / Sign up

Export Citation Format

Share Document