Ayman Zyada
Biography
Mr Zyada is a Vascular Surgeon with extensive experience across several major vascular units in the United Kingdom. His clinical practice spans the full spectrum of vascular surgery, including both open and endovascular procedures, with a strong commitment to delivering high-quality, evidence-based patient care.
Alongside his clinical work, Mr Zyada is actively engaged in academic research, with multiple publications in peer-reviewed journals and presentations at national and international conferences. His research interests include vascular outcomes, surgical education, and the integration of emerging technologies into clinical practice.
Mr Zyada is passionate about training and mentorship, regularly contributing to surgical teaching and audit initiatives. His long-term goal is to pursue an academic career in vascular surgery that combines clinical excellence, research innovation, and the advancement of vascular science within the NHS.
Research Interest
His research interests focus on vascular outcomes, surgical education, and the integration of emerging technologies into clinical practice.
Abstract
Title: Conformable EVAR stability in hostile neck abdominal aortic aneurysms: A single centre experience
Abstract
Background: Stent graft migration is a well-recognized complication of endovascular aneurysm repair (EVAR) that can predispose patients to type I endoleaks, renal artery compromise, and secondary interventions specially with hostile neck anatomy which poses a significant technical challenge for graft fixation. The GORE Excluder Conformable AAA Endoprosthesis (CLEVAR) is specifically designed to address these challenges by accommodating neck lengths as short as 10 mm, diameters down to 16 mm, and angulations up to 90?. This study aimed to evaluate the early stability of CLEVAR in patients with hostile neck anatomy by investigating its migration behaviour within the f irst postoperative year.
Methodology: A retrospective analysis was conducted on consecutive patients undergoing repair of hostile neck abdominal aortic aneurysm with the CLEVAR device between January 2019 and December 2022. Eligible patients had completed both 3-month and 1-year postoperative computed tomography angiography (CTA). Migration was assessed by measuring the distance between the proximal stent edge and bilateral renal arteries at both time points, with the difference representing stent movement. Descriptive statistics were calculated, normality was tested with the Shapiro?Wilk method, and comparisons employed non-parametric Wilcoxon signed-rank tests.
Results: A total of 25 patients were included. Mean stent migration across the cohort was 1.29 mm (SD 1.36 mm), with a median of 0.85 mm and maximum migration of 6.0 mm. Both right and left renal reference points showed similar results (mean 1.17 mm and 1.40 mm, respectively), with no statistically significant difference between sides (p = 0.4261). Migration distributions were non-normally distributed and positively skewed. Analysis confirmed that stent displacement was statistically greater than zero (p < 0.00000001), indicating measurable, albeit small, positional changes during the interval.
Conclusion: In this study, the CLEVAR device demonstrated stable proximal fixation in challenging hostile neck anatomies over the first postoperative year. Observed migration was minimal, symmetrical, and generally well below thresholds considered clinically significant. These findings suggest CLEVAR provides reliable early stability in anatomically complex aneurysm necks, potentially reducing the risk of migration associated complications. However, the small sample size, retrospective design, and one-year follow-up limit generalizability. Longer-term studies with larger cohorts are required to determine the durability of fixation and the relationship between late migration, endoleak incidence, and need for reintervention.
