Bench test and in vivo evaluation of longitudinal stent deformation during proximal optimisation

Gabor G Toth, Alexandru Achim, Marcel Kafka, Xinlei Wu, Mattia Lunardi, Sinjini Biswas, Atif Shahzad, Attila Thury, Zoltan Ruzsa, Thomas W Johnson, William Wijns

Research output: Contribution to journalArticlepeer-review


BACKGROUND: While radial stent deformation has been thoroughly investigated, data on longitudinal deformation are scarce.

AIMS: The aim of the study was to describe longitudinal stent deformation associated with the proximal optimisation technique (POT).

METHODS: Longitudinal stent deformation was assessed by bench testing and by clinical evaluation. Bench testing was performed in silicone models using 3.00 (n=15) and 3.50 mm (n=14) stent platforms. After deployment, stents were sequentially post-dilated in the proximal main branch up to 5.50 mm, in increments of 0.50 mm, in order to simulate a spectrum of overexpansion. Stent length was redefined by optical coherence tomography (OCT) after each step. Clinical data were collected retrospectively from OCT-guided bifurcation percutaneous coronary intervention cases.

RESULTS: In bench tests, POT has led to significant stent elongation in all cases. The magnitude of elongation was comparable between the 3.00 and the 3.50 mm stent platforms, with 0.86±0.74 mm vs 0.86±0.73 mm, respectively (p=0.71), per 0.5 mm overexpansion. For 3.00 mm stent platforms, maximal elongation was 4.31±1.47 mm after up to 5.5 mm overexpansion. For 3.50 mm platforms, maximal elongation was 2.87±0.94 mm after up to 5.5 mm overexpansion. Thirty-six clinical cases were analysed, of which 22 (61%) were performed in the distal left main. Post-dilation was performed with 0.98±0.36 mm absolute overexpansion, resulting in 2.22±1.35 mm elongation, as compared to nominal stent length.

CONCLUSIONS: Overexpansion by POT results in proximal stent elongation. This has to be considered once the stent length is selected and the stent is positioned, especially in the left main stem, where proximal overexpansion is marked and accurate ostial landing is critical.

Original languageEnglish
Pages (from-to)83-90
Number of pages8
Issue number1
Early online date20 Dec 2021
Publication statusPublished - 15 May 2022

Bibliographical note

Funding Information:
G. Toth receives personal fees from Abbott, Medtronic, Terumo and Biotronik, outside the present work. T. Johnson has received personal fees from Abbott, Boston Scientific, Medtronic and Terumo, outside the present work. W. Wijns has received institutional research grants from MicroPort and is supported by a Science Foundation Ireland Research Professorship grant (15/RP/2765). X. Wu, M. Lunardi and A. Shahzad are supported by a Science Foundation Ireland Research Professorship grant (15/RP/2765). The other authors have no conflicts of interest to declare.

Publisher Copyright:
© Europa Digital & Publishing 2022.


  • Angioplasty, Balloon, Coronary/methods
  • Coronary Angiography
  • Coronary Vessels/diagnostic imaging
  • Humans
  • Percutaneous Coronary Intervention
  • Prosthesis Design
  • Retrospective Studies
  • Stents
  • Tomography, Optical Coherence
  • bifurcation
  • drug-eluting stent
  • left main

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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