| 1. |
- Bondesson, Johan, 1991, et al.
(författare)
-
Cardiac Pulsatile Helical Deformation of the Thoracic Aorta Before and After Thoracic Endovascular Aortic Repair of Type B Dissections
- 2023
-
Ingår i: Journal of Endovascular Therapy. - 1545-1550 .- 1526-6028. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Type B aortic dissections propagate with either achiral (nonspiraling) or right-handed chiral (spiraling) morphology, have mobile dissection flaps, and are often treated with thoracic endovascular aortic repair (TEVAR). We aim to quantify cardiac-induced helical deformation of the true lumen of type B aortic dissections before and after TEVAR. Material and Methods: Retrospective cardiac-gated computed tomography (CT) images before and after TEVAR of type B aortic dissections were used to construct systolic and diastolic 3-dimensional (3D) surface models, including true lumen, whole lumen (true+false lumens), and branch vessels. This was followed by extraction of true lumen helicity (helical angle, twist, and radius) and cross-sectional (area, circumference, and minor/major diameter ratio) metrics. Deformations between systole and diastole were quantified, and deformations between pre- and post-TEVAR were compared. Results: Eleven TEVAR patients (59.9 +/- 4.6 years) were included in this study. Pre-TEVAR, there were no significant cardiac-induced deformations of helical metrics; however, post-TEVAR, significant deformation was observed for the true lumen proximal angular position. Pre-TEVAR, cardiac-induced deformations of all cross-sectional metrics were significant; however, only area and circumference deformations remained significant post-TEVAR. There were no significant differences of pulsatile deformation from pre- to post-TEVAR. Variance of proximal angular position and cross-sectional circumference deformation decreased after TEVAR. Conclusion: Pre-TEVAR, type B aortic dissections did not exhibit significant helical cardiac-induced deformation, indicating that the true and false lumens move in unison (do not move with respect to each other). Post-TEVAR, true lumens exhibited significant cardiac-induced deformation of proximal angular position, suggesting that exclusion of the false lumen leads to greater rotational deformations of the true lumen and lack of true lumen major/minor deformation post-TEVAR means that the endograft promotes static circularity. Population variance of deformations is muted after TEVAR, and dissection acuity influences pulsatile deformation while pre-TEVAR chirality does not. Clinical Impact Description of thoracic aortic dissection helical morphology and dynamics, and understanding the impact of thoracic endovascular aortic repair (TEVAR) on dissection helicity, are important for improving endovascular treatment. These findings provide nuance to the complex shape and motion of the true and false lumens, enabling clinicians to better stratify dissection disease. The impact of TEVAR on dissection helicity provides a description of how treatment alters morphology and motion, and may provide clues for treatment durability. Finally, the helical component to endograft deformation is important to form comprehensive boundary conditions for testing and developing new endovascular devices.
|
|
| 2. |
- Bondesson, Johan, 1991, et al.
(författare)
-
Definition of Tubular Anatomic Structures from Arbitrary Stereo Lithographic Surface
- 2017
-
Ingår i: Initiative Seminar Engineering Health, 8-9 November 2017, Chalmers.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- An accurate description of anatomies and dynamics of vessels is crucial to understand their characteristics and improve surgical techniques, thus it is the basis, in addition to surgeon experience, on which stent design and operation procedures rely. The process of producing this description is user intensive, and recent improvement in image processing of medical3D imaging allows for a more automated workflow. However, there is a need to bridge the gap from a processed geometry to a robust mathematical computational grid. By sequentially segmenting a tubular anatomic structure, here defined by a stereo lithographic (STL) surface, an initial centerline is formed by connecting centroids of orthogonal cross-sectional contours along the length of the structure. Relying on the initial centerline, a set of non-overlapping 2D cross sectional contours are defined along the centerline, a centerline which is updated after the 2D contours are produced. After a second iteration of producing 2D contours and updating the centerline, a full description of the structure is created. Our method for describing vessel geometry shows good coherence to existing method. The main advantages of our method include the possibility of having arbitrary triangulated STL surface input, automated centerline definition, safety against intersecting cross-sectional contours and automatic clean-up of local kinks and wrinkles.
|
|
| 3. |
- Bondesson, Johan, 1991, et al.
(författare)
-
Influence of Thoracic Endovascular Aortic Repair on True Lumen Helical Morphology for Stanford Type B Dissections
- 2021
-
Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 0741-5214 .- 1097-6809. ; 74:5, s. 1499-1507.e1
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Thoracic endovascular aortic repair (TEVAR) can change the morphology of the flow lumen in aortic dissections, which may affect aortic hemodynamics and function. This study characterizes how the helical morphology of the true lumen in type B aortic dissections is altered by TEVAR. Methods: Patients with type B aortic dissection who underwent computed tomography angiography before and after TEVAR were retrospectively reviewed. Images were used to construct three-dimensional stereolithographic surface models of the true lumen and whole aorta using custom software. Stereolithographic models were segmented and co-registered to determine helical morphology of the true lumen with respect to the whole aorta. The true lumen region covered by the endograft was defined based on fiducial markers before and after TEVAR. The helical angle, average helical twist, peak helical twist, and cross-sectional eccentricity, area, and circumference were quantified in this region for pre- and post-TEVAR geometries. Results: Sixteen patients (61.3 ± 8.0 years; 12.5% female) were treated successfully for type B dissection (5 acute and 11 chronic) with TEVAR and scans before and after TEVAR were retrospectively obtained (follow-up interval 52 ± 91 days). From before to after TEVAR, the true lumen helical angle (–70.0 ± 71.1 to –64.9 ± 75.4°; P =.782), average helical twist (–4.1 ± 4.0 to –3.7 ± 3.8°/cm; P =.674), and peak helical twist (–13.2 ± 15.2 to –15.4 ± 14.2°/cm; P =.629) did not change. However, the true lumen helical radius (1.4 ± 0.5 to 1.0 ± 0.6 cm; P <.05) and eccentricity (0.9 ± 0.1 to 0.7 ± 0.1; P <.05) decreased, and the cross-sectional area (3.0 ± 1.1 to 5.0 ± 2.0 cm2; P <.05) and circumference (7.1 ± 1.0 to 8.0 ± 1.4 cm; P <.05) increased significantly from before to after TEVAR. The distinct bimodal distribution of chiral and achiral native dissections disappeared after TEVAR, and subgroup analyses showed that the true lumen circumference of acute dissections increased with TEVAR, although it did not for chronic dissections. Conclusions: The unchanged helical angle and average and peak helical twists as a result of TEVAR suggest that the angular positions of the true lumen are constrained and that the endografts were helically conformable in the angular direction. The decrease of helical radius indicated a straightening of the corkscrew shape of the true lumen, and in combination with more circular and expanded lumen cross-sections, TEVAR produced luminal morphology that theoretically allows for lower flow resistance through the endografted portion. The impact of TEVAR on dissection flow lumen morphology and the interaction between endografts and aortic tissue can provide insight for improving device design, implantation technique, and long-term clinical outcomes.
|
|
| 4. |
|
|
| 5. |
- Bondesson, Johan, 1991, et al.
(författare)
-
Quantification of True Lumen Helical Morphology and Chirality in Type B Aortic Dissections
- 2021
-
Ingår i: American Journal of Physiology - Heart and Circulatory Physiology. - : American Physiological Society. - 1522-1539 .- 0363-6135. ; 320:2, s. H901-H911
-
Tidskriftsartikel (refereegranskat)abstract
- Chirality is a fundamental property in many biologic systems. Motivated by previous observations of helical aortic blood flow, aortic tissue fibers, and propagation of aortic dissections, we introduce methods to characterize helical morphology of aortic dissections. After validation on computer generated phantoms, the methods were applied to patients with type B dissection. For this cohort, there was a distinct bimodal distribution of helical propagation of the dissection with either achiral or exclusively right-handed chirality, with no intermediate cases or left-handed cases. This clear grouping indicates that dissection propagation favors these two modes, potentially due to the right-handedness of helical aortic blood flow and cell orientation. The characterization of dissection chirality and quantification of helical morphology advances our understanding of dissection pathology and lays a foundation for applications in clinical research and treatment practice. For example, the chirality and magnitude of helical metrics of dissections may indicate risk of dissection progression, help define treatment and surveillance strategies, and enable development of novel devices that account for various helical morphologies.
|
|
| 6. |
|
|
| 7. |
- Frohlich, Maxfield M., et al.
(författare)
-
Thoracic aortic geometry correlates with endograft bird-beaking severity
- 2020
-
Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 0741-5214 .- 1097-6809. ; 72:4, s. 1196-1205
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Aortic geometry has been shown to influence the development of endograft malapposition (bird-beaking) in thoracic endovascular aortic repair (TEVAR), but the extent of this relationship lacks clarity. The aim of this study was to develop a reproducible method of measuring bird-beak severity and to investigate preoperative geometry associated with bird-beaking. Methods: The study retrospectively analyzed 20 patients with thoracic aortic aneurysms or type B dissections treated with TEVAR. Computed tomography scans were used to construct three-dimensional geometric models of the preoperative and postoperative aorta and endograft. Postoperative bird-beaking was quantified with length, height, and angle; categorized into a bird-beak group (BBG; n = 10) and no bird-beak group (NBBG; n = 10) using bird-beak height ≥5 mm as a threshold; and correlated to preoperative metrics including aortic cross-sectional area, inner curvature, diameter, and inner curvature × diameter as well as graft diameter and oversizing at the proximal landing zone. Results: Aortic area (1002 ± 118 mm2 vs 834 ± 248 mm2), inner curvature (0.040 ± 0.014 mm−1 vs 0.031 ± 0.012 mm−1), and diameter (35.7 ± 2.1 mm vs 32.2 ± 4.9 mm) were not significantly different between BBG and NBBG; however, inner curvature × diameter was significantly higher in BBG (1.4 ± 0.5 vs 1.0 ± 0.3; P =.030). Inner curvature and curvature × diameter were significantly correlated with bird-beak height (R = 0.462, P =.041; R = 0.592, P =.006) and bird-beak angle (R = 0.680, P <.001; R = 0.712, P <.001). Conclusions: TEVAR bird-beak severity can be quantified and predicted with geometric modeling techniques, and the combination of high preoperative aortic inner curvature and diameter increases the risk for development of TEVAR bird-beaking.
|
|
| 8. |
- Lundh, Torbjörn, 1965, et al.
(författare)
-
A Lagrangian cylindrical coordinate system for characterizing dynamic surface geometry of tubular anatomic structures
- 2018
-
Ingår i: Medical and Biological Engineering and Computing. - : Springer Science and Business Media LLC. - 0140-0118 .- 1741-0444. ; 56:9, s. 1659-1668
-
Tidskriftsartikel (refereegranskat)abstract
- © 2018 The Author(s) Vascular morphology characterization is useful for disease diagnosis, risk stratification, treatment planning, and prediction of treatment durability. To quantify the dynamic surface geometry of tubular-shaped anatomic structures, we propose a simple, rigorous Lagrangian cylindrical coordinate system to monitor well-defined surface points. Specifically, the proposed system enables quantification of surface curvature and cross-sectional eccentricity. Using idealized software phantom examples, we validate the method’s ability to accurately quantify longitudinal and circumferential surface curvature, as well as eccentricity and orientation of eccentricity. We then apply the method to several medical imaging data sets of human vascular structures to exemplify the utility of this coordinate system for analyzing morphology and dynamic geometric changes in blood vessels throughout the body. [Figure not available: see fulltext.]
|
|
| 9. |
|
|
| 10. |
- Suh, Ga Young, et al.
(författare)
-
Ascending Aortic Endograft and Thoracic Aortic Deformation After Ascending Thoracic Endovascular Aortic Repair
- 2023
-
Ingår i: Journal of Endovascular Therapy. - 1545-1550 .- 1526-6028. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: We aim to quantify multiaxial cardiac pulsatility-induced deformation of the thoracic aorta after ascending thoracic endovascular aortic repair (TEVAR) as a part of the GORE ARISE Early Feasibility Study. Materials and Methods: Fifteen patients (7 females and 8 males, age 73±9 years) with ascending TEVAR underwent computed tomography angiography with retrospective cardiac gating. Geometric modeling of the thoracic aorta was performed; geometric features including axial length, effective diameter, and centerline, inner surface, and outer surface curvatures were quantified for systole and diastole; and pulsatile deformations were calculated for the ascending aorta, arch, and descending aorta. Results: From diastole to systole, the ascending endograft exhibited straightening of the centerline (0.224±0.039 to 0.217±0.039 cm−1, p<0.05) and outer surface (0.181±0.028 to 0.177±0.029 cm−1, p<0.05) curvatures. No significant changes were observed for inner surface curvature, diameter, or axial length in the ascending endograft. The aortic arch did not exhibit any significant deformation in axial length, diameter, or curvature. The descending aorta exhibited small but significant expansion of effective diameter from 2.59±0.46 to 2.63±0.44 cm (p<0.05). Conclusion: Compared with the native ascending aorta (from prior literature), ascending TEVAR damps axial and bending pulsatile deformations of the ascending aorta similar to how descending TEVAR damps descending aortic deformations, while diametric deformations are damped to a greater extent. Downstream diametric and bending pulsatility of the native descending aorta was muted compared with that in patients without ascending TEVAR (from prior literature). Deformation data from this study can be used to evaluate the mechanical durability of ascending aortic devices and inform physicians about the downstream effects of ascending TEVAR to help predict remodeling and guide future interventional strategies. Clinical Impact: This study quantified local deformations of both stented ascending and native descending aortas to reveal the biomechanical impact of ascending TEVAR on the entire thoracic aorta, and reported that the ascending TEVAR muted cardiac-induced deformation of the stented ascending aorta and native descending aorta. Understanding of in vivo deformations of the stented ascending aorta, aortic arch and descending aorta can inform physicians about the downstream effects of ascending TEVAR. Notable reduction of compliance may lead to cardiac remodeling and long-term systemic complications. This is the first report which included dedicated deformation data regarding ascending aortic endograft from clinical trial.
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
- Suh, Ga Young, et al.
(författare)
-
Multiaxial pulsatile dynamics of the thoracic aorta and impact of thoracic endovascular repair
- 2021
-
Ingår i: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: The thoracic aorta is a highly mobile organ whose dynamics are altered by thoracic endovascular aorta repair (TEVAR). The aim of this study was to quantify cardiac pulsatility-induced multi-axial deformation of the thoracic aorta before and after descending aortic TEVAR. Methods: Eleven TEVAR patients (8 males and 3 females, age 57–89) underwent retrospective cardiac-gated CT angiography before and after TEVAR. 3D geometric models of the thoracic aorta were constructed, and lumen centerlines, inner and outer surface curves, and cross-sections were extracted to measure aortic arclength, centerline, inner surface, and outer surface longitudinal curvatures, as well as cross-sectional effective diameter and eccentricity for the ascending and stented aortic portions. Results: From pre- to post-TEVAR, arclength deformation was increased at the ascending aorta from 5.9 ± 3.1 % to 8.8 ± 4.4 % (P < 0.05), and decreased at the stented aorta from 7.5 ± 5.1 % to 2.7 ± 2.5 % (P < 0.05). Longitudinal curvature and diametric deformations were reduced at the stented aorta. Centerline curvature, inner surface curvature, and cross-sectional eccentricity deformations were increased at the distal ascending aorta. Conclusions: Deformations were reduced in the stented thoracic aorta after TEVAR, but increased in the ascending aorta near the aortic arch, possibly as a compensatory mechanism to maintain overall thoracic compliance in the presence of reduced deformation in the stiffened stented aorta.
|
|
| 14. |
- Niemi, MEK, et al.
(författare)
-
- 2021
-
swepub:Mat__t
|
|
