International Journal of Gastrointestinal Intervention · Published 2026-02-24 · DOI 10.18528/ijgii250085
Background : Improved survival among patients after esophageal stenting has led to an increasing number of long-term stent failures. To better understand the mechanisms of stent fracture, a baseline study was conducted to assess the changes that stents undergo in vivo. Methods : Stents removed from patients during revision procedures were analyzed in an industry-standard laboratory. Scanning electron microscopy (SEM) with elemental surface mapping was performed, followed by tensile stress testing of individual wires. Results : Six stents were examined after endoscopic removal for migration (n = 2), pre-radical radiotherapy (n = 2), development of an esophageal fistula (n = 1), and stent fracture (n = 1). The median dwell time was 70 days (range, 7-201). The retrieved stents included both braided and knitted types, as well as partially and fully covered stents from three different manufacturers. SEM revealed deformation of the nitinol wires and evidence of brittle failure. Numerous surface deposits were observed, providing a nidus for surface erosion and crack propagation. Elemental mapping identified the surface deposits as primarily consisting of carbon and sodium chloride. Tensile stress testing demonstrated a marked loss of strength and superelasticity, with erratic breaking strain. Some wire samples fractured spontaneously before testing. Conclusion : Even in this small and heterogeneous sample, there was clear evidence of a corrosive process leading to the rapid degradation of nitinol properties. This process appeared to affect different stents in a similar manner and at an alarming rate, suggesting that in most patients, esophageal stents are likely to fail within their lifetime.
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