O-002 - STATIC AND DYNAMIC RENAL AND VISCERAL ARTERY GEOMETRY AFTER FEVAR

TOPIC:
Abdominal Aortic Aneurysms
AUTHORS:
Simmering J. (Multi-modality Medical Imaging (M3i) Group, Faculty of Science and Technology, Technical Medical Centre, University of Twente ~ Enschede ~ Netherlands) , Koenrades M. (3D-lab, Medisch Spectrum Twente ~ Enschede ~ Netherlands) , Reijnen M. (Department of Surgery (Division of Vascular Surgery), Rijnstate hospital ~ Arnhem ~ Netherlands) , Zeebregts C. (Department of Surgery (Division Vascular Surgery), University Medical Center Groningen ~ Groningen ~ Netherlands) , Slump K. (Robotics and Mechatronics (RaM) Group, faculty of Electrical Engineering, Mathematics and Computer Science, Technical Medical Centre, University of Twente ~ Enschede ~ Netherlands) , Groot Jebbink E. (MultiModality Medical Imaging (M3i) Group, University of Twente ~ Enschede ~ Netherlands) , Geelkerken B. (Department of Surgery (Division of Vascular Surgery), Medisch Spectrum Twente ~ Enschede ~ Netherlands)
Introduction:
Fenestrated endovascular aorta repair (FEVAR) is currently the dominant treatment for complex abdominal aortic aneurysms (AAA)[1,2]. FEVAR has shown high technical success rates (84-100%)[3-5] and good short and mid-term results with 30-day mortality of 0-7%[4-6]. Given the 1-year reintervention-free survival rates of 80.0-96.5%[3,7,8], there is still room for improvement. This may find its origin in our limited understanding of the static and dynamic geometry of the stent-graft and branches and their potential influence on FEVAR-durability. Electrical cardiogram (ECG)-gated computed tomography angiography (CTA) is a technique that allows cardiac-pulsatility-induced geometry quantification of the aorta and implanted devices[9-12]. Hence, the aim of this study was to increase our understanding of the static and dynamic geometry of the aorta branch arteries pre- and post-FEVAR, using ECG-gated CTA.
Methods:
Twenty-one FEVAR patients treated with a fenestrated Anaconda (Terumo Aortic, Inchinnan, Scotland, UK) were prospectively enrolled in a national multicenter observational cohort study. The patients underwent ECG-gated CTA preoperatively, before discharge and at 6-8 weeks and 12 months follow-up. The ECG-gated CTA scans were reconstructed into 10 equidistant volumes covering the cardiac cycle (0-90%). These 10 CTA-volumes were registered to a single phase-averaged static volume with improved resolution and signal-to-noise ratio using a previously defined registration algorithm[13-15]. This registration also provides deformation fields to translate voxels and measurement in the phase-averaged volume back to the original phases' volumes and thereby diminishes user dependence in the analyses. Static and dynamic branch geometry was investigated by deriving geometrical parameters from center lumen lines (CLLs), through the aortic side branches from its ostium to the first branch artery bifurcation. These parameters were: branch angle, as the angle between the aorta and the upstream part of the branch CLL (Figure 1A); end-stent angle, as the angle between 10 mm CLL vectors of the distal end of the branch stent and the first part of the downstream native artery (Figure 1A); branch tortuosity index (TI), as the branch CLL length divided by the straight distance between the CLL ends (Figure 1B); branch curvature, as a numerical parameter for CLL bending, in 2D represented as the inverse of the radius of a circle fitted to the CLL (Figure 1C).
Results:
The mean branch angle increased after FEVAR from 59.9° to 74.9° (increase of 15.0°, standard error [SE] 3.5°, 95% confidence interval [CI] 5.8-24.2°, p<0.001), which continued to increase during the first year follow-up toward a 90° angle between the aorta and the side branch, especially in the renal arteries. The end-stent angle was on average 156.0° before FEVAR and did not change statistical significantly over time (p>0.430). During the cardiac cycle the branch angle and end-stent angles changed up to 5°, regardless of the scan moment (p=1.000). The TI and curvature remained stable during the cardiac cycle and during follow-up for all branches, except for the left renal artery (LRA). The LRAs showed less cardiac pulsatility induced change in TI and curvature at the 6-8 weeks and 12 months follow-up moments compared to the preoperative situation (p<0.030).
Conclusion:
FEVAR increased the angle between the aorta and the renal and visceral arteries significantly. During follow-up, especially the renal arteries go toward a perpendicular (90°) position relative to the aorta. This can probably be attributed to the combination of the stiff branch stents (Advanta V12, Atrium Medical, Hudson, NH), the zero-column-strength FEVAR body and the arteries' ability to adapt. Furthermore, the other investigated geometrical parameters up to the first branch artery bifurcation remain constant after FEVAR and during follow-up, indicating that the increased branch angle should be compensated at another location, most likely downstream the first branch artery bifurcation. Moreover, the limited and stable cardiac-pulsatility-induced geometry changes indicate a stable configuration, which is thought to favor the clinical outcome. Interestingly, a patient with an endoleak of the superior mesenteric artery (SMA) and coeliac artery (CA) had steep preoperative branch angles (31.1° and 47.2°, respectively) that increased strongly after FEVAR (56.0° and 93.0°, respectively). This may suggest that small branch angles are more prone to endoleaks since the stiff branch stents induce strong forces on the branch artery and fenestration. In conclusion, the fenestrated Anaconda has stable dynamic and static geometry, except for the perpendicular maneuvering of the branches.
References:
1 Huang IKH, Renani SA, Morgan RA. Complications and Reinterventions After Fenestrated and Branched EVAR in Patients with Paravisceral and Thoracoabdominal Aneurysms. Cardiovasc Intervent Radiol 2018;41(7):985-97. Doi: 10.1007/s00270-018-1917-0. 2 Wanhainen A, Verzini F, van Herzeele I, Allaire E, Bown M, Cohnert T, et al. European Society for Vascular Surgery (ESVS) 2019 Clinical Practice Guidelines on the Management of Abdominal Aorto-iliac Artery Aneurysms. Eur J Vasc Endovasc Surg 2019;57(1):8-93. Doi: 10.1016/j.ejvs.2018.09.020. 3 Dijkstra ML, Tielliu IFJ, Meerwaldt R. Dutch experience with the fenestrated Anaconda endograft for short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair. J Vasc Surg 2013;60(2):301-7. Doi: 10.1016/j.jvs.2014.02.011. 4 Rolls AE, Jenkins M, Bicknell CD, Riga CV, Cheshire NJ. Experience with a novel custom-made fenestrated stent graft in the repair of juxtarenal and type IV thoracoabdominal aneurysms. J Vasc Surg 2014;59(3):615-622.e1. Doi: 10.1016/j.jvs.2013.10.038. 5 Gallitto E, Faggioli G, Melissano G, Fargion A. Preoperative and postoperative predictors of clinical outcome of fenestrated and branched endovascular repair for complex abdominal and thoracoabdominal aortic aneurysms in an Italian multicenter registry. J Vasc Surg 2021;74(6):1795-1806.e6. Doi: 10.1016/j.jvs.2021.04.072. 6 Midy D, Becquemin J, Mialhe C, Frisch N. Results of the French Multicentric Study of ANACONDA Ô Fenestrated Endografts in the Treatment of Complex Aortic Pathologies (EFEFA Registry). Ann Vasc Surg 2017;43:151-65. Doi: 10.1016/j.avsg.2017.03.171. 7 Falkensammer J, Taher F, Uhlmann M, Hirsch K, Strassegger J, Assadian A. Rescue of failed endovascular aortic aneurysm repair using the fenestrated Anaconda device. J Vasc Surg 2017;66(5):1334-9. Doi: 10.1016/j.jvs.2017.02.048. 8 Blankensteijn LL, Dijkstra ML, Tielliu IFJ, Reijnen MMPJ, Zeebregts CJ, Zeebregts CJ, et al. Midterm results of the fenestrated Anaconda endograft for short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair. J Vasc Surg 2017;65(2):303-10. Doi: 10.1016/j.jvs.2016.08.092. 9 Koenrades MA, Struijs EM, Klein A, Kuipers H, Reijnen MMPJ, Slump CH, et al. Quantitative Stent Graft Motion in ECG Gated CT by Image Registration and Segmentation: In Vitro Validation and Preliminary Clinical Results. Eur J Vasc Endovasc Surg 2019;58(5):746-55. Doi: 10.1016/j.ejvs.2019.03.009. 10 van Helvert M, Simmering JA, Koenrades MA, Slump CH, Heyligers JMM, Geelkerken RH, et al. Evaluation of ECG-gated CTA to quantify changes in geometry and dynamic behavior of the iliac artery after placement of the Gore Excluder Iliac Branch Endoprosthesis. J Cardiovasc Surg 2022. Doi: 10.23736/S0021-9509.22.11980-4. 11 Koenrades MA, Klein A, Leferink AM, Slump CH, Geelkerken RH. Evolution of the Proximal Sealing Rings of the Anaconda Stent-Graft After Endovascular Aneurysm Repair. J Endovasc Ther 2018;25(4):480-91. Doi: 10.1177/1526602818773085. 12 van Keulen JW, van Prehn J, Prokop M, Moll FL, van Herwaarden JA. Dynamics of the Aorta Before and After Endovascular Aneurysm Repair: A Systematic Review. Eur J Vasc Endovasc Surg 2009;38(5):586-96. Doi: 10.1016/j.ejvs.2009.06.018. 13 Koenrades MA, Struijs EM, Klein A, Kuipers H, Geelkerken RH, Slump CH. Validation of an image registration and segmentation method to measure stent graft motion on ECG-gated CT using a physical dynamic stent graft model. Med Imaging 2017 Comput Diagnosis 2017;10134(March 2017):1013418. Doi: 10.1117/12.2254262. 14 Klein A, Kroon D-J, Hoogeveen Y, Schultze Kool LJ, Renema WKJ, Slump CH. Multimodal image registration by edge attraction and regularization using a B-spline grid. Med Imaging 2011 Image Process 2011;7962:796220. Doi: 10.1117/12.878267. 15 Klein A, Renema WKJ, van der Vliet JA, Oostveen LJ, Hoogeveen Y, Schultze Kool, Leo J. Slump CH. Motion Calculations on Stent Grafts in AAA. In: Grundmann RT, editor. Diagnosis, Screening and Treatment of Abdominal, Thoracoabdominal and Thoracic Aortic Aneurysms. Rijeka: InTechOpen; 2011. pp. 125-44.
ATTACHMENTS: