Issue 100 | November 2023
Advertorial 21
THIS ADVERTORIAL IS SPONSORED BY SHAPE MEMORY MEDICAL
The path toward the gold standard in clinical evidence—a randomised controlled trial
In focus: smart polymer treatment of abdominal aortic aneurysm (AAA) sacs during endovascular aneurysm repair (EVAR).
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mart polymer device treatment of the flow lumen outside of an endograft during elective EVAR is an exciting prospect, Shape Memory Medical tells Vascular News. Smart polymer devices have numerous properties that formed the basis of an initial investigation into their potential to improve AAA sac behaviour: a porous matrix that supports thrombus formation throughout its structure. The open-cell structure of smart polymer also contributes to its radiolucency, low radial force, and conformability (Figure 1). Prospective single-arm studies in New Zealand NCT04227054 and The Netherlands NCT04751578 developed a technique to manage the AAA sac outside of an endograft with IMPEDE-FX RapidFill during EVAR.1 A guidewire and delivery sheath are placed in the blood lumen, outside the endograft where the smart polymer is delivered throughout the AAA sac (supplemental video in doi:10.1016/j.jvscit.2023.101241).1 The studies have completed enrolment, and one-year results are currently being written up for publication (Figure 2). With feasibility study data in hand, what is next for smart polymer technology and EVAR? Shape Memory Medical recently announced that the US Food and Drug Administration (FDA) granted investigational device exemption (IDE) for a prospective, multicentre, randomised, open-label trial to compare the performance of smart polymer treatment of a AAA sac during EVAR versus standard EVAR as a control (Figure 3). The design of the AAA-SHAPE Pivotal Trial (NCT06029660) incorporates contemporary ideas in AAA treatment. A key endpoint is the change in AAA volume. Aortic diameter is currently the gold standard measure for
AAA and EVAR. However, rapidly emerging data and analyses suggest aneurysm volume may be an earlier and more sensitive marker of changes in AAA morphology than diameter in surveillance,2–4 treatment thresholds, and interventional followup.5–8 Imaging technology is also rapidly evolving to facilitate the use of volume measurement in clinical practice, both for computed tomography (CT)9,10 and three-dimensional ultrasound11–14 assessments. Since volumetric measurements are three dimensional, they are able to detect minor changes compared to two-dimensional diameter changes. Therefore, both volume and diameter should be measured.20 Endicott and Simons recently noted: “Current aneurysm guidelines utilise sac stability as an endpoint for successful EVAR; however, recent studies have suggested that a stable (not shrinking) sac may in fact portend increased mortality with time.” They suggest “how success of EVAR is defined in terms of sac behavior” as a priority for the field.15 Indeed, numerous retrospective studies have recently linked an absence of sac regression to increased mortality.16–19 The results of the prospective AAA-SHAPE Pivotal Trial, with standard EVAR as the control and sac treatment with smart polymer under investigation, will generate high-quality data to describe AAA sac behaviour post EVAR, regardless of the arm. The primary endpoint will explore the effectiveness of the approach and long-term followup will explore whether smart polymer improves patient outcomes post EVAR. “We look forward to the journey ahead and the collaboration with our clinical investigators in the USA and Europe,” Shape Memory Medical shares with Vascular News.
References 1. H olden A, Hill AA, Khashram M, et al. Active aortic aneurysm sac treatment with shape memory polymer during endovascular aneurysm repair. J Vasc Surg Cases Innov Tech. 2023;9(3):101241. 2. R istl R, Klopf J, Scheuba A, et al. Comparing maximum diameter and volume when assessing the growth of small abdominal aortic aneurysms using longitudinal CTA data: Cohort study. Int J Surg. 2023. 3. O lson SL, Panthofer AM, Blackwelder W, et al. Role of volume in small abdominal aortic aneurysm surveillance. J Vasc Surg. 2022;75(4):1260– 1267 e1263. 4. Renapurkar RD, Setser RM, O’Donnell TP, et al. Aortic volume as an indicator of disease progression in patients with untreated infrarenal abdominal aneurysm. Eur J Radiol. 2012;81(2):e87–93. 5. Fillinger M, Excluder Bifurcated Endoprosthesis Clinical I. Threedimensional analysis of enlarging aneurysms after endovascular abdominal aortic aneurysm repair in the Gore Excluder pivotal clinical trial. J Vasc Surg. 2006;43(5):888–895. 6. van Keulen JW, van Prehn J, Prokop M, et al. Potential value of aneurysm sac volume measurements in addition to diameter measurements after endovascular aneurysm repair. J Endovasc Ther. 2009;16(4):506−513. 7. Franchin M, Serafini M, Tadiello M, et al. A morphovolumetric analysis of aneurysm sac evolution after elective endovascular abdominal aortic repair. J Vasc Surg. 2021;74(4):1222–1231 e1222. 8. G unerhan Y, Isik M, Dereli Y, et al. Assessing volumetric changes in abdominal aortic aneurysms following endovascular repair. Cardiovasc J Afr. 2021;32(4):182–187. 9. Caradu C, Pouncey AL, Lakhlifi E, et al. Fully automatic volume segmentation using deep learning approaches to assess aneurysmal sac evolution after infrarenal endovascular aortic repair. J Vasc Surg. 2022;76(3):620–630 e623. 10. Spinella G, Fantazzini A, Finotello A, et al. Artificial intelligence application to screen abdominal aortic aneurysm using computed tomography angiography. J Digit Imaging. 2023. 11. Zielinski AH, Bredahl KK, Ghulam QM, et al. Full-volume assessment of abdominal aortic aneurysm by improved-field-of-view 3D ultrasound performs comparably to computed tomographic angiography. Ultrasound Med Biol. 2022;48(2):283–292. 12. Zielinski AH, Bredahl KK, Ghulam QM, et al. One-year volume growth of abdominal aortic aneurysms measured by extended field-of-view ultrasound. Int Angiol. 2023;42(1):80–87. 13. Khan M, Rogers S, Carreira J, et al Aneurysm geometry analyzed by the novel three-dimensional tomographic ultrasound relates to abdominal aortic aneurysm growth. Ann Vasc Surg. 2022;87:469–477. 14. Maas EJ, Nievergeld AHM, Fonken JHC, et al. 3D ultrasound-based mechanical and geometrical analysis of abdominal aortic aneurysms and relationship to growth. Ann Biomed Eng. 2023. 15. Endicott KM, Simons JP. Essential innovation and clinical trial needs in vascular care: Aortic. Endovascular Today. https://evtoday.com/ articles/2023-aug/essential-innovation-and-clinical-trial-needs-invascular-care?c4src=current:feed. Published 2023. Accessed Sept 2023. 16. O’Donnell TFX, Deery SE, Boitano LT, et al. Aneurysm sac failure to regress after endovascular aneurysm repair is associated with lower long-term survival. J Vasc Surg. 2019;69(2):414−422. 17. Al-Tawil M, Muscogliati E, Jubouri M, et al. Correlative effect between sac regression and clinical outcomes following endovascular repair in abdominal aortic aneurysm: Fact or myth? Expert Rev Med Devices. 2023;20(8):643–650. 18. Pla Sanchez F, Martinez Lopez I, Hernandez Mateo MM, et al. Prognostic value of initial aneurysmal sac regression after evar. Ann Vasc Surg. 2020;64:109–115. 19. Boer GJ, Schroder LBW, Disli MC, et al. A stable aneurysm sac after endovascular aneurysm repair as a predictor for mortality: An in-depth analysis. J Vasc Surg. 2022;76(2):445–453. 20. van Keulen JW, van Prehn J, Prokop M, et al. Potential value of aneurysm sac volume measurements in addition to diameter measurements after endovascular aneurysm repair. Journal of endovascular therapy: an official journal of the International Society of Endovascular Specialists. Aug 2009;16(4):506–13. doi:10.1583/09-2690.1
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Disclaimers: The content contains information about the AAA-SHAPE Pivotal Trial, Shape Memory Medical’s prospective, multicenter, randomized, open-label trial of the IMPEDE-FX RapidFill when used for prophylactic abdominal aortic aneurysm (AAA) sac filling during elective endovascular aneurysm repair (EVAR). For more information about the AAA-SHAPE Studies, please visit https://clinicaltrials.gov/study/NCT06029660. In countries recognizing CE marking, IMPEDEFX RapidFill is indicated to obstruct or reduce the rate of blood flow in the peripheral vasculature. The IMPEDE-FX RapidFill device is not approved for sale in the United States. Caution – INVESTIGATIONAL DEVICE, LIMITED BY FEDERAL (OR UNITED STATES) LAW TO INVESTIGATIONAL USE.