Fatigue and/or Failure Phenomena Observed in the Fabric of Stent-Grafts Explanted After Adverse Events

Abstract

In this study, we aimed to investigate changes to the fabric of Talent stent-grafts following implantation of aortic endografts and to determine the possible causes of fatigue and/or failure of the grafts. Six devices were explanted at reoperation (N=5) and autopsy (N=1). Selected segments were assessed nondestructively by gross observation and destructively by analyzing textile characteristics and chemical properties. All of the devices showed a 4/4 twill woven fabric of monofilament polyester. These devices, explanted at reoperation and autopsy, presented different levels of fatigue and/or failure. Numerous holes were found in the fabric of two devices. The minor damage caused by the passage of the sutures through the weave to fasten the Nitinol wires did not progress significantly over time. The sutures remained relatively intact, except for some distortions. The main failure mode was the abrasion of the yarns at the apices of adjacent Nitinol stents. In two devices, this abrasion resulted in fraying of the yarns and holes in the fabric tubes. This short series of explanted devices provides evidence of damage to polyester fabric used in aortic endografts and raises questions regarding their resistance to abrasion and the risk of endoleak associated with monofilament fabric yarn.

Midterm Follow-up of Fenestrated and Scalloped Physician-Modified Endovascular Grafts for Zone 2 TEVAR

“…[12][13][14][15] Although our fenestration technique cuts only the stent-graft fabric leaving the struts intact, in our earlier reports we expressed concern about the longterm durability of this approach. Metal fatigue and material deterioration are known complications of stent-grafting, 18 and it has been hypothesized that custom-modified stent-grafts in the arch may be particularly vulnerable due to the asymmetric force distribution. 19,20 This study demonstrates that these PMEGs continue to perform well at least in the midterm; no cases of stent fracture have been detected in follow-up.…”

Innovative textile structures designed to prevent type III endoleaks in endovascular stent‐grafts

“…15,20 Most of the developments have been industry-driven in response to an identification of these failures published in clinical studies. 21 One of the most significant improvements was the recognition of the need to dampen the apices (30°-45°) of the stent-graft in devices. 43,44 With the shift toward surgeons performing a greater number of percutaneous procedures, combined with the desire to extend treatment to patients with both smaller diameter and more tortuous iliac arteries, even smaller devices were developed.…”

Explanted Vascular and Endovascular Graft Analysis: Where Do We Stand and What Should We Do?

“…However, new generation explanted endografts have rarely been analysed and there is no clear superiority of one type of endograft over another. 30,31 Recent data has allowed characterisation of textile ageing through a specific qualitative classification of various degradation mechanisms observed on new generation explanted endografts (Fig. 8).…”