In Vitro Radiological Evaluation of Different Types of Chimney Stents Using a Silicon Flow Model with Adjustable Physiological Simulating Conditions

Gergana T Taneva; Marco V Usai; Georgios A Pitoulias; Konstantinos P Donas

doi:10.1016/j.ejvs.2023.05.005

In Vitro Radiological Evaluation of Different Types of Chimney Stents Using a Silicon Flow Model with Adjustable Physiological Simulating Conditions

Eur J Vasc Endovasc Surg. 2023 Aug;66(2):270-277. doi: 10.1016/j.ejvs.2023.05.005. Epub 2023 May 10.

Authors

Gergana T Taneva¹, Marco V Usai², Georgios A Pitoulias³, Konstantinos P Donas⁴

Affiliations

¹ Department of Vascular Surgery and Angiology, Puerta de Hierro and Montepríncipe University Hospitals, Madrid, Spain. Electronic address: [email protected].
² Department of Vascular Surgery, St Franziskus Hospital Münster, Münster, Germany.
³ 2nd Department of Surgery, Division of Vascular Surgery, Aristotle University of Thessaloniki, Thessaloniki, Greece.
⁴ Department of Vascular Surgery, Asklepios Clinic Langen, Langen, Germany, and Department of Vascular Surgery, University Hospital Bern, Bern, Switzerland.

PMID: 37172689
DOI: 10.1016/j.ejvs.2023.05.005

Abstract

Objective: To evaluate in vitro the performance of in vivo published covered or bare metal chimney stents (ChSs) in combination with the Endurant II abdominal endograft (Medtronic) as the only CE approved main graft (MG) in the treatment of juxtarenal abdominal aortic aneurysms with the chimney endovascular aneurysm repair (chEVAR) technique.

Methods: Bench top experimental study. A silicon flow model with adjustable physiological simulating conditions and patient based anatomy was used to test nine different MG-ChS combinations: Advanta V12 (Getinge); BeGraft⁺ (Bentley); VBX (Gore & Associates Inc.); LifeStream (Bard Medical); Dynamic (Biotronik); Absolute Pro (Abbott); double Absolute Pro; Viabahn (Gore) lined with Dynamic; and Viabahn lined with EverFlex (Medtronic). Angiotomography was performed after each implantation. DICOM data were analysed blindly twice per observer by three independent experienced observers. Each blinded evaluation was performed at one month intervals. The main analysed parameters were the area of gutters, MG and ChS maximum compression, and the presence of infolding.

Results: Bland-Altman analysis confirmed adequate results correlation (p < .05). Each employed ChS showed significantly different performance favouring the balloon expandable covered stent (BECS). The smallest gutter area was seen in the combination with Advanta V12 (0.26 cm²). MG infolding was observed in all tests. The lowest ChS compression was observed in the combination with BeGraft⁺ (compression 4.91%, D ratio 0.95). In our model, BECSs showed higher angulations than bare metal stents (BMSs) (p < .001).

Conclusion: This in vitro study shows the variability of performance with each theoretically possible ChS and explains the divergent ChS outcomes in the published literature. BECS in combination with the Endurant abdominal device confirms their superiority vs. BMS. The presence of MG infolding in each test underlines the need for prolonged kissing ballooning. Angulation evaluation and comparison with other in vitro and in vivo publications demands the need for further investigation in transversely or upwardly oriented target vessels.

Keywords: Benchtop; Chimney stent; In vitro; Juxtarenal abdominal aortic aneurysm.

MeSH terms

Aortic Aneurysm, Abdominal* / diagnostic imaging
Aortic Aneurysm, Abdominal* / surgery
Blood Vessel Prosthesis
Blood Vessel Prosthesis Implantation*
Endovascular Procedures*
Humans
Prosthesis Design
Silicon
Stents
Treatment Outcome

Substances

Silicon