Migration of stent grafts following an endovascular aneurysm repair, a reappraisal of current definitions: an analysis of prevalence, prognosis, and review of surveillance strategies
File(s)
Author(s)
Abdullah, Ammar Adel
Type
Thesis
Abstract
The introduction of endovascular aneurysm repair (EVAR) has transformed the treatment of abdominal aortic aneurysms, yet stent graft migration remains a complication driven by intrinsic aortic changes. A lack of standardisation complicates reporting; a systematic review identified 18 definitions, with only "≥10mm or intervention" showing robust historical validity.
This study assessed migration rates across two tertiary vascular centres using a standardised protocol. Migration prevalence varied by definition: 20.7% (≥5mm), 11.3% (≥10mm), and 14.7% (≥10mm or intervention). Migration ≥10mm was associated with a significantly higher risk of proximal seal failure compared to migration at 5-9.9mm (27% vs 5%, p=0.001). The average time to migration was 63.6 months, confirming it as a long-term complication.
Crucially, "early migration" (≥5mm within 18 months) was identified as a powerful predictor of eventual ≥10mm migration (OR 139.3, CI 39.15-495.6, p<0.001). This provides a practical, accessible screening tool for identifying high-risk patients.
Additionally, freehand electromagnetic 3D ultrasound successfully reconstructed a phantom aorta to measure EndoAnchor positions. This demonstrates a foundation for future non-invasive, radiation-free post-operative surveillance despite current challenges with EndoAnchor visualisation.
This study assessed migration rates across two tertiary vascular centres using a standardised protocol. Migration prevalence varied by definition: 20.7% (≥5mm), 11.3% (≥10mm), and 14.7% (≥10mm or intervention). Migration ≥10mm was associated with a significantly higher risk of proximal seal failure compared to migration at 5-9.9mm (27% vs 5%, p=0.001). The average time to migration was 63.6 months, confirming it as a long-term complication.
Crucially, "early migration" (≥5mm within 18 months) was identified as a powerful predictor of eventual ≥10mm migration (OR 139.3, CI 39.15-495.6, p<0.001). This provides a practical, accessible screening tool for identifying high-risk patients.
Additionally, freehand electromagnetic 3D ultrasound successfully reconstructed a phantom aorta to measure EndoAnchor positions. This demonstrates a foundation for future non-invasive, radiation-free post-operative surveillance despite current challenges with EndoAnchor visualisation.
Version
Open Access
Date Issued
2024-09-30
Date Awarded
01/01/2026
License URL
Advisor
Bicknell, Colin
Riga, Celia
Sponsor
National Institute for Health Research (Great Britain)
Grant Number
P69139
Publisher Department
Department of Surgery & Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)