International Angiology 2022 Feb 09

DOI: 10.23736/S0392-9590.22.04773-3

Copyright © 2022 EDIZIONI MINERVA MEDICA

language: English

Mechanical characteristics of venous stents to overcome challenges of venous outflow obstruction

Chung S. LIM ^{1, 2} ✉, Stephen A. BLACK ³

¹ Department of Vascular Surgery, Royal Free London NHS Foundation Trust, London, UK; ² Division of Surgery and Interventional Science, Department of Surgical Biotechnology, Faculty of Medical Sciences, University College London, UK; ³ Academic Department of Vascular Surgery, School of Cardiovascular Medicine and Sciences, King’s College London, BHF Centre of Excellence, Guy’s and St Thomas’ Hospital NHS Foundation Trust, London, UK

BACKGROUND: Many challenges posed by the venous outflow obstruction (VOO) are unique to the venous system which require specific mechanical characteristics of stents to overcome them. Therefore, this article aims to review and discuss these challenges and the stent mechanical characteristics required to overcome them.
METHODS: A literature search was performed with Pubmed with the terms “mechanical characteristics of venous stents” and “mechanical properties of venous stents”.
RESULTS: The venous system poses unique anatomical, physiological and pathological challenges when compared to the arterial counterpart. Several mechanical characteristics specific to venous stents which include the size, inherent forces, and flexibility are important to overcome these unique challenges when treating VOO. The most important stent inherent forces for venous stents include the chronic outward force, radial resistive force, and crush resistance. Various stent materials and designs, particularly laser-cut versus braided-structure stents, and open-cell versus closed-cell stents, determine the mechanical characteristics including the inherent forces of the venous stents. The desired mechanical characteristics of stents needed to overcome the venous system challenges often in conflict or with opposing effects. Therefore, it is important to fine adjust and optimise these characteristics.
CONCLUSIONS: There are many anatomical, physiological, and pathological challenges unique to the venous system which need to be overcome by the stent system mechanically when treating VOO. Therefore, dedicated venous stents with optimal mechanical characteristics are being developed with different designs and properties to treat VOO. Further research and innovations are needed to improve the stent technology that targets the venous system specifically.

KEY WORDS: Stent; Venous; Iliofemoral vein; Post-thrombotic syndrome; Non-thrombotic iliac vein lesion; Crush resistance