Dissection flap fenestration can reduce re-apposition force of the false lumen in type-B aortic dissection: a computational and bench study
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SUBMITTER: Ahuja A
PROVIDER: S-EPMC11007646 | biostudies-literature | 2024 Jan
REPOSITORIES: biostudies-literature
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Project description:While much about the fundamental mechanisms behind the initiation and progression of Type B aortic dissection (TBAD) is still unknown, predictive models based on patient-specific computational fluid dynamics (CFD) can help in risk stratification and optimal clinical decision-making. Aiming at the development of personalized treatment, CFD simulations can be leveraged to investigate the interplay between complex aortic flow patterns and anatomical features. In this study, the hemodynamics of false lumen thrombosis, a large fenestration, and the orbital orientation of the false lumen is studied through image-based CFD simulations on three TBAD patient-specific geometries. A new pipeline was developed leveraging the open-source software SimVascular and Paraview to analyze multiple patients simultaneously and to achieve large-scale parallelization in CFD results based on patients' computed tomography (CT) images. The results of this study suggest that the internal orbital orientation of the false lumen contributes to maintaining a positive luminal pressure difference ΔPTL-FL=PTL-PFL between the true lumen (TL) and the false lumen (FL), despite an impingement area in the false lumen near the entry tear. A positive and high luminal pressure difference is thought to promote TL expansion and FL compression. Moreover, it was also found that both FL thrombosis at the entry tear region, and the presence of a large fenestration in the descending thoracic aorta reduce the magnitude of the negative luminal pressure difference, which in turn may reduce FL expansion and the risk of unstable aortic growth.
| S-EPMC10980148 | biostudies-literature
Project description: Not available
| S-EPMC10981118 | biostudies-literature
Project description:Re-expansion of thrombosed false lumen after aortic dissection due to collateral retrograde flow from the aortic branches has rarely been reported. Surgical or endovascular local management such as ligation or occlusion of culprit arteries may not be effective in case retrograde blood flow to the false lumen might occur again from another branch after the operation. Here, we report a 68-year-old woman with re-expansion of the thrombosed false lumen after acute type B aortic dissection due to collateral retrograde flow from the aortic branches successfully treated with tranexamic acid therapy and antihypertensive therapy.
| S-EPMC8752932 | biostudies-literature
Project description: Not available
| S-EPMC5758447 | biostudies-literature
Project description:ObjectivesWe aimed to determine whether non-A non-B aortic dissection (AD) differs in morphologic and haemodynamic properties from type B AD.MethodsWe simulated and compared haemodynamics of patients with acute type B or acute non-A non-B AD by means of computational fluid dynamics. Wall pressure and wall shear stress (WSS) in both the true lumen (TL) and false lumen (FL) at early, mid- and late systole were evaluated. Morphology, WSS and the FL/TL wall pressure ratio were compared between groups.ResultsNineteen patients (type B, n = 7; non-A non-B, n = 12) were included. The median age (51 [46, 67] vs 53 [50, 63] years; P = 0.71) and a complicated course (14% vs 33%; P = 0.6) did not differ between the type B group and the non-A non-B group. However, the median entry tear width was increased in the non-A non-B group (9.7 [7.3, 12.7] vs 16.3 [11.9, 24.9] mm; P = 0.010). Streamlines showed, in patients with non-A non-B AD, blood from the TL flowed into the FL via the entry tear. Prevalence of a FL/TL wall pressure ratio >1.0 (type B versus non-A non-B) at early, mid- and late systole was 57% vs 83% (P = 0.31), 43% vs 83% (P = 0.13) and 57% vs 75% (P = 0.62), respectively. WSS did not differ between the groups.ConclusionsThe increased FL/TL wall pressure ratio observed during systole in non-A non-B AD may beget a complicated presentation.
| S-EPMC9486891 | biostudies-literature
Project description:ObjectivesCurrent risk assessment strategies in type B aortic dissection are focused on anatomic parameters, although haemodynamic abnormalities that result in false lumen (FL) pressurization are thought to play a significant role in aortic growth. The objective of this study was to evaluate blood flow of the FL using 4D flow magnetic resonance imaging (MRI) and identify haemodynamic and anatomic factors that independently predict the rate of aortic growth.MethodsPatients with dissection of the descending thoraco-abdominal aorta (n = 18) were enrolled in a prospective observational study and underwent 4D flow MRI for haemodynamic assessment of the entry tear and FL. Anatomic parameters were obtained by magnetic resonance angiography and baseline computed tomography. False lumen ejection fraction (FL EF) was defined the ratio of retrograde flow rate at the dominant entry tear during diastole over the antegrade systolic flow rate.ResultsThe median aortic growth rate was 3.5 mm/year (interquartile range 0.5-8.1 mm/year). Entry tear peak velocity was lower in patients with enlarging aortic dimensions (95.5 ± 24.1 vs 128.1 ± 37.4 cm/s, P = 0.039). After adjusting for co-variates FL EF (β = 0.15, P = 0.004), baseline maximal aortic diameter (β = 0.37, P = 0.001) and the entry tear distance from the left subclavian artery (β = 0.07, P = 0.016) were significant predictors of aortic growth rate.ConclusionsBeyond standard anatomic risk factors, FL EF is an independent predictor of aortic growth rate and may represent an intuitive, non-invasive method to estimate FL pressurization and improve patient-specific risk assessment in patients with type B aortic dissection.
| S-EPMC8453376 | biostudies-literature
Project description:ObjectivesIn uncomplicated type B aortic dissection, a large false lumen (FL) is reportedly a risk factor for late aortic events. However, it is unclear how the relationship between the false and true lumen (TL) diameters affects the dissected aorta. This study aimed to evaluate the impact on clinical outcomes of the FL being larger than the TL.MethodsWe retrospectively reviewed 111 consecutive patients with uncomplicated acute type B aortic dissection between 2004 and 2018. We divided the patients into group A (FL > TL; n = 51) and group B (FL ≤ TL; n = 60), and compared the outcomes. The endpoints were aortic events, including surgery for aortic dissection and indication for surgery, and mortality.ResultsThe 5-year incidence rates of aortic events were 68.4% in Group A and 33.6% in Group B (P = 0.002). The 5-year all-cause mortality rates were 5.3% in Group A and 21.9% in Group B (P = 0.003). The multivariable analyses revealed that FL > TL was an independent factor associated with aortic events (adjusted hazard ratio 2.482, 95% confidence interval 1.467-4.198, P < 0.001), but had low mortality (adjusted hazard ratio 0.209, 95% confidence interval 0.073-0.597, P = 0.003).ConclusionsPatients with uncomplicated type B aortic dissection with FL > TL at admission are at increased risk of aortic events but improve mortality compared to patients with FL ≤ TL.Clinical trial registrationUMIN000036997.
| S-EPMC9714601 | biostudies-literature
Project description:We investigated the influence of false lumen (FL) status on the systemic inflammatory response triggered by acute aortic dissection (AAD) using cytokine profiling. The study included 44 patients with AAD. Patients were divided between those with a thrombosed FL (Group T, n = 21) and those with a non-thrombosed FL (Group P, n = 23). On-admission serum concentrations of 29 cytokines were compared between unmatched and propensity-score matched (n = 10 pairs) FL groups and a control group (non-ruptured thoracic aortic aneurysm, Group C, n = 20). Unmatched analysis showed 12 cytokines differed between groups and fell into three categories: Category A (increased expression in both FL groups: IL-6, IL-10, IL-15, G-CSF); Category B (increased expression only in Group P: IL-1Ra, IL-1β, IL-8, IL-12p70, GM-CSF); and Category C (others: IP-10, VEGF-A, eotaxin). The increases in Category A and Category B cytokines in Group T were attenuated, but not significantly, compared to their increases in Group P. Propensity-score matching analysis revealed a similar expression pattern with respect to all four Category A cytokines, four Category B cytokines (IL-1β, IL-1Ra, IL-12p70, and GM-CSF), and two Category C cytokines (IP-10 and VEGF-A). A robust inflammatory response occurs in patients with AAD, but the response is attenuated when the FL is thrombosed.
| S-EPMC11696800 | biostudies-literature
Project description:Objective: Thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) aims to induce false lumen (FL) thrombosis by sealing intimal tears between the true (TL) and the FL, and blocking the inflow into the FL. Incomplete thrombosis of the FL is correlated with poor clinical outcome. We hypothesize that the number of major and minor branches arising from the FL affects FL patency and may negatively influence TEVAR induced FL thrombosis. Methods: Computed tomography (CT)-scans from 89 patients diagnosed with TBAD [best medical treatment (BMT) n = 52, TEVAR n = 37] from two high-volume vascular surgery centers were analyzed retrospectively. Analysis included evaluation of the FL patency status, the number, location and size of intimal tears, and the presence of minor and major side branches originating from the FL. Multiple regression analysis was conducted to evaluate obtained parameters as predictors for FL thrombosis status. Results: In univariate analysis, the strongest correlation for FL patency was found for the number of major (R = 0.79) and minor (R = 0.86) side branches originating from the FL. When applying a multiple linear regression model, the number of major (normalized beta 0.37; P < 0.001) and minor (normalized beta 0.41; P < 0.01) side branches arising from the FL were valid predictors for the axial length of the patent and non-patent FL, and additionally determined the length of the patent FL at 12-month follow-up in patients that underwent TEVAR. Conclusions: Our data suggest that the number of minor side branches that originate from the FL in TBAD is an important determinant of FL patency, to a greater degree than previously assumed.
| S-EPMC8414589 | biostudies-literature
Project description:IntroductionIn chronic aortic dissection complicated by aneurysmal degeneration, the absence of spontaneous tears between the true and false lumen at visceral artery level may limit treatment by fenestrated/branched endovascular aneurysm repair (F/BEVAR). The creation of new fenestrations may be required to allow access to the visceral vessels.TechniqueIn this video, the endovascular treatment of a 70 year old white man with chronic type B aortic dissection complicated by Crawford type II thoraco-abdominal aortic aneurysmal degeneration is presented. The right renal artery had a false lumen origin without nearby visible re-entry tears. He underwent dissection flap fenestration at visceral vessel level using a transjugular intrahepatic portosystemic shunt (TIPS) needle and subsequent dilation with a high pressure balloon. A Zenith TX2 dissection endovascular graft was deployed proximally and extended distally with a Zenith dissection endovascular stent until the fenestration level was reached. In a second stage, a F/BEVAR was performed, with fenestration to the left renal artery and branches to right renal artery, superior mesenteric artery, and coeliac trunk. One year follow up computed tomography angiography showed visceral branch patency and a reduction of the aneurysm sac.DiscussionThe chronic dissection flap may be thick and fibrotic, creating a technical challenge for endovascular fenestration. The off label use of a TIPS needle in this procedure created a new fenestration at the desired level and allowed definitive post-dissection treatment of the thoraco-abdominal aneurysm.
| S-EPMC8358633 | biostudies-literature