Left atrial appendage shape impacts on the left atrial flow hemodynamics: A numerical hypothesis generating study on two cases

Alinezhad, Lida; Ghalichi, Farzan; Ahmadlouydarab, Majid; Chenaghlou, Maryam

doi:10.1016/j.cmpb.2021.106506

Cited by 17 publications

(11 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, velocity profiles and flow patterns were considerably different in the LAA between the boundary conditions. First, we observed that the rigid case exhibited no oscillations across the LAA orifice—a phenomenon previously observed in LAAs of comparable complexity, 17 which may be a sign of low washout. Second, the generic case displayed only minor flow instabilities, but exhibited an increased cardiac output based off the area under the curve.…”

Section: Discussionsupporting

confidence: 59%

“…For these reasons, computational fluid dynamics (CFDs) has been used to complement the available imaging techniques and provide a more detailed analysis of the blood flow in the LA. CFD has previously been used to study how atrial hemodynamics is impacted by anatomy, such as pulmonary vein (PV) configuration [12][13][14][15] and LAA complexity, 16,17 volume, 15 and morphology. 13,[18][19][20][21] Other studies have investigated functional aspects, such as loss of contraction 19,[22][23][24][25] and the influence of fibrotic regions, 26 as well as the impact of surgical procedures, including left upper lobectomy 27 and LAA occlusion.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Impact of left atrial wall motion assumptions in fluid simulations on proposed predictors of thrombus formation

Kjeldsberg,

Albors,

Mill

et al. 2024

Numer Methods Biomed Eng

View full text Add to dashboard Cite

Atrial fibrillation (AF) poses a significant risk of stroke due to thrombus formation, which primarily occurs in the left atrial appendage (LAA). Medical image‐based computational fluid dynamics (CFD) simulations can provide valuable insight into patient‐specific hemodynamics and could potentially enhance personalized assessment of thrombus risk. However, the importance of accurately representing the left atrial (LA) wall dynamics has not been fully resolved. In this study, we compared four modeling scenarios; rigid walls, a generic wall motion based on a reference motion, a semi‐generic wall motion based on patient‐specific motion, and patient‐specific wall motion based on medical images. We considered a LA geometry acquired from 4D computed tomography during AF, systematically performed convergence tests to assess the numerical accuracy of our solution strategy, and quantified the differences between the four approaches. The results revealed that wall motion had no discernible impact on LA cavity hemodynamics, nor on the markers that indicate thrombus formation. However, the flow patterns within the LAA deviated significantly in the rigid model, indicating that the assumption of rigid walls may lead to errors in the estimated risk factors. In contrast, the generic, semi‐generic, and patient‐specific cases were qualitatively similar. The results highlight the crucial role of wall motion on hemodynamics and predictors of thrombus formation, and also demonstrate the potential of using a generic motion model as a surrogate for the more complex patient‐specific motion. While the present study considered a single case, the employed CFD framework is entirely open‐source and designed for adaptability, allowing for integration of additional models and generic motions.

show abstract

Section: Discussionsupporting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

Impact of left atrial wall motion assumptions in fluid simulations on proposed predictors of thrombus formation

Kjeldsberg,

Albors,

Mill

et al. 2024

Numer Methods Biomed Eng

View full text Add to dashboard Cite

show abstract

“…Pre‐procedural CCT scanning is increasingly utilized and recognized as a powerful tool in the planning of LAA closure, as it allows additional insights into patient‐specific anatomy 5,21 . Several studies have underlined the importance to obtain the most accurate LAA dimensions through multi‐modal imaging (2D‐TEE, 3D‐TEE, fluoroscopy, CCT, fusion imaging) to prevent device recaptures, intra‐procedural device changes and prolonged procedure duration resulting in higher doses of contrast dye and radiation 22–24 …”

Section: Discussionmentioning

confidence: 99%

“…5,21 Several studies have underlined the importance to obtain the most accurate LAA dimensions through multi-modal imaging (2D-TEE, 3D-TEE, fluoroscopy, CCT, fusion imaging) to prevent device recaptures, intraprocedural device changes and prolonged procedure duration resulting in higher doses of contrast dye and radiation. [22][23][24] Apart from the difficulties that stem from the anatomical variance of the LAA, the transseptal puncture is another step prone to complications during the procedure. In this context, successful coaxial device deployment depends on the ability to position the delivery sheath with sufficient depth into the LAA, with the long axis of the LAA oriented anteriorly and the plane of the LAA ostium perpendicular to that axis, this is accomplished with a posterior-anterior trajectory of the sheath.…”

Section: Discussionmentioning

confidence: 99%

The CT derived angle between the transseptal puncture site and the left atrial appendage as a predictor for complex interventional occlusion procedures

Nelles,

Amli,

Sugiura

et al. 2023

Echocardiography

View full text Add to dashboard Cite

ObjectiveTo evaluate the role of the CT‐derived angle between the intra‐atrial septum (IAS) and the left atrial appendage (LAA) on procedural complexity and clinical outcomes in left atrial appendage occlusion (LAAO) procedures.BackgroundGiven the broad variations in anatomy, LAAO remains one of the most challenging interventional procedures in structural heart disease. In recent years, preprocedural cardiac tomography (CT) has evolved as a valuable tool; however, prediction of procedural complexity remains cumbersome.MethodsWe retrospectively analyzed 47 patients that underwent LAAO at our center in whom pre‐procedural cardiac CT‐scans were available. Among other baseline parameters, we measured the angle between the LAA ostium and the preferred transseptal puncture site at the IAS. We compared patients with an angle above and below the median regarding procedural characteristics and procedural outcome.ResultsThe median angle between the LAA and the IAS was 127.3° (IQR: 120.9–141.3). LAAO took longer in patients with a measured angle below the median (55.0 ± 22.7 min vs. 41.3 ± 17.5 min; p = .04), resulting in longer radiation times (13.0 ± 5.3 min vs. 9.8 ± 5.7 min; p = .04) and more contrast use (61.1 ± 47.5 mL vs. 33.6 ± 24.7 mL; p = .05). Moreover, the necessity for a sheath exchange was significantly higher (30.4% vs. 4.2%, p = .02) and device repositioning or device resizing trended to be more frequent (26.1% vs. 8.3%; p = .1 and 21.7% vs. 8.3%; p = .2). There were no differences in procedural outcome, device‐position and peri‐device leak (PDL).ConclusionsThe angle between the transseptal puncture site and the LAA ostium may serve as a predictor for more demanding LAAO interventions. In our study a steeper angle led to a prolonged procedure resulting in higher doses of contrast and radiation, but was not associated with a worse procedural outcome.

show abstract

“…To build an ideal predictive model, it may be necessary to take so many indicators together and view them comprehensively. For example, a lower swirl range or blood flow velocity and more than two lobules and a large LAA volume in patients with AF have a relatively higher risk of thrombosis, while a complex LAA with seven lobules was affected by other factors, such as opening diameter and volume, and reached the lowest risk of coagulation among all study cases ( 40 , 62 ). What we will worry about is that, even though we ultimately find the exact indicators for risk prediction, the comprehensive analysis of that multi-index model is still undoubtedly beyond men’s power.…”

Section: Limitations and Future Directionmentioning

confidence: 93%

Finding low CHA2DS2-VASc scores unreliable? Why not give morphological and hemodynamic methods a try?

Sun

Chen

et al. 2023

Front. Cardiovasc. Med.

View full text Add to dashboard Cite

Patients with atrial fibrillation (AF) suffer from a high risk of thrombosis. Currently, the CHA2DS2-VASc score is the most widely used tool for risk stratification in patients with AF, but it has disappointing accuracy and limited predictive value, especially in those with low scores. Thrombi in patients with AF mostly grow in their left atrial appendages (LAA), which is directly related to the abnormal morphology of the LAA or the left atrium and the unusual hemodynamic state around LAA, which may sensitively evaluate the risk of thrombosis complications in patients with AF and bring bases to clinical plans of medication and operation. Therefore, we investigated the research progress of hemodynamic and morphological studies about the predictive value of thrombosis risk in patients with AF, intending to discuss the prediction potential of morphological and hemodynamic indexes when compared with the presently used CHA2DS2-VASc system and how to build a more precise thromboembolic event prediction model for patients with AF.

show abstract

Left atrial appendage shape impacts on the left atrial flow hemodynamics: A numerical hypothesis generating study on two cases

Cited by 17 publications

References 48 publications

Impact of left atrial wall motion assumptions in fluid simulations on proposed predictors of thrombus formation

Impact of left atrial wall motion assumptions in fluid simulations on proposed predictors of thrombus formation

The CT derived angle between the transseptal puncture site and the left atrial appendage as a predictor for complex interventional occlusion procedures

Finding low CHA2DS2-VASc scores unreliable? Why not give morphological and hemodynamic methods a try?

Contact Info

Product

Resources

About