The Influence of Different Types of Stent Grafts on Aneurysm Neck Dynamics after Endovascular Aneurysm Repair

Department of Vascular Surgery, University Medical Center Utrecht, The Netherlands.
European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery (Impact Factor: 2.49). 10/2009; 39(2):193-9. DOI: 10.1016/j.ejvs.2009.10.006
Source: PubMed


Dynamic imaging provides insight into aortic shape changes throughout the cardiac cycle. These changes may be important for proximal aortic stent graft fixation, sealing and durability. The objective of this study is to analyse the influence of different types of stent grafts on dynamic changes of the aneurysm neck.
Pre- and postoperative electrocardiography (ECG)-gated computed tomographic angiography (CTA) scans were obtained in 30 abdominal aortic aneurysm (AAA) patients, 10 each from three different types of stent grafts (10 Talent, Endurant, and Excluder). Each dynamic CTA dataset consisted of eight reconstructed images over the cardiac cycle. Aortic area and radius changes during the cardiac cycle were determined at two levels: (A) 3 cm above and (B) 1 cm below the lowermost renal artery. Radius changes were measured over 360 axes, and plotted in a polar plot. An ellipse was fitted over the plots to determine radius changes over the major and minor axis for assessment of the asymmetric aspect and most prominent direction of distension.
Baseline characteristics did not differ significantly between the three groups. Preoperatively, the aortic area increased significantly (p < 0.001) over the cardiac cycle in all patients at both levels: (A) mean increase 8.3 +/- 4.1% (2.0-17.3%); (B) mean increase 5.9 +/- 4.2% (1.9-12.4%). The postoperative aortic area increase over the cardiac cycle did not differ significantly from preoperative increases: (A) mean increase 9.9 +/- 2.2% (4.4-20.0%); (B) mean increase 7.7 +/- 2.4% (3.8-12.4%). The difference between radius change over the major and minor axis was significant both pre- and postoperatively for all three stent grafts, indicating asymmetric distension. Suprarenal, the distension showed a tendency to right-anterior and infrarenal to left-anterior. The distension and direction of the aortic expansion was preserved after stent grafting. There were no differences between the three types of stent grafts regarding their impact on the aortic distension or direction of this distension.
The aorta expands significantly and asymmetrically throughout the cardiac cycle. After implantation of abdominal aortic stent grafts, the aortic distension and direction of distension remain equally preserved in all three groups. The three stent graft types studied seem to be able to adapt to the asymmetric dynamic aortic shape changes.

Full-text preview

Available from:
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) is a long-term 1200-patient multicenter prospective study initiated to augment the knowledge base (poolable and comparable) about endovascular aortic repair (EVAR) in a real-world population implanted with a single latest-generation stent graft system (Endurant). With enrollment ongoing at 80 high-volume sites, the registry has limited inclusion/exclusion criteria or procedural specification. Technical and clinical data will be reported through 5 years. An interim analysis was performed on investigator-reported data for the first 180 patients enrolled. These patients were asymptomatic elderly males (92.1%) with considerable comorbidities. For 47.3% of the patients, the American Society of Anesthesiologists risk class was either III or IV. The Endurant stent graft was successfully deployed in 99.4% of patients for elective treatment of abdominal aortic aneurysm. Through 30 days, the rate of all-cause mortality was 1.7% (N=3), with all 3 deaths classified as procedure-related but not device-related. The rate of secondary endovascular procedures was 1.1%, and the rate of conversion to open repair was 0.6%. At postprocedure and at 30-day follow-up, there were no type I or type III endoleaks and no instances of stent graft kinking, thrombosis, or occlusion. ENGAGE represents the largest real-world registry for any single EVAR stent graft. The interim results through 30 days of the first 180 patients enrolled are promising. Longer-term follow-up for more patients will be reported.
    No preview · Article · Aug 2010 · The Journal of cardiovascular surgery
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The proximal abdominal aortic aneurysm (AAA) neck expands significantly during the cardiac cycle, both before and after endovascular aneurysm repair (EVAR). Clinical consequences of this pulsatility were anticipated but have never been reported. This study investigated whether there is a relation between stent graft migration and preoperatively measured pulsatility of the proximal aneurysm neck. EVAR patients with a preoperative dynamic computed tomography angiography (CTA), an immediate postoperative, and a CTA at 3 years after EVAR were included. The preoperative dynamic CTAs consisted of eight images per heartbeat. Aortic diameter and area changes per heartbeat were measured at two levels: (A) 3 cm above and (B) 1 cm below the most distal renal artery. Postoperatively, the distance between the most distal renal artery and the most proximal stent graft ring was measured. Two patient groups were distinguished according to whether migration during follow-up occurred (group 1) or had not occurred (group 2). The aneurysm neck dynamics of the two groups were compared by using the t-test for unpaired data and multivariable logistic regression analyses were performed. Mean values are presented with the standard deviation. Included were 26 patients (19 Talent, 6 Excluder and 1 Lifepath). Stent graft migration of > or =5 mm occurred in 11 patients (group 1). The pulsatility of the AAA neck in these patients was compared with the pulsatility in 15 patients with no graft migration (group 2). There were no significant differences in aortic neck characteristics (angulation, length and diameter) or degree of stent graft oversizing between the two groups. At level A in group 1 versus group 2, the diameter increase during the cardiac cycle was 2.0 +/- 0.3 versus 1.7 +/- 0.3 mm and the aortic area increase was 49 +/- 15 versus 33 +/- 12 mm(2). At level B in group 1 versus group 2, the diameter increase per heartbeat was 1.8 +/- 0.3 versus 1.6 +/- 0.4 mm, and the area increase was 37 +/- 10 versus 25 +/- 15 mm(2). The heartbeat-dependent diameter and area changes at both levels were significantly higher in group 1 compared with group 2. Multivariate regression analysis showed suprarenal aortic pulsatility was a significant predictor for stent graft migration after 3 years. The preoperative heartbeat-dependent aneurysm neck distension is significantly associated with stent graft migration after 3 years. The aortic pulsatility in patients with stent graft migration is significantly higher than the pulsatility in patients without stent graft migration.
    Preview · Article · Sep 2010 · European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Endurant Stent-graft System (Medtronic Vascular, Santa Rosa, CA) is a next-generation device intended to expand the applicability of endovascular aortic repair (EVAR). To date, the Endurant has been evaluated in 9 short- and intermediate-term studies, several in patients presenting with challenging aneurysm anatomies. Consistently, the device in these studies has been shown to be safe and effective, with an excellent rate of deployment success and with very low rates of type I/III endoleaks and reinterventions. Single center experience with Endurant in challenging anatomies with short kinked necks and calcified angulated iliac arteries in patients unfit for open repair and challenging anatomies show promising early results with no difference in mortality, morbidity and reintervention rates, but need cautious application for EVAR outside of the device-specific IFU. The Endurant Stent-graft Natural Selection Global Postmarket Registry (ENGAGE) is a long-term 1266-patient 80-site worldwide prospective postmarket study initiated to augment the knowledge base (poolable and comparable) about EVAR in a real-world population implanted with the Endurant. Technical and clinical data for ENGAGE patients will be reported through the expected completion of 5-year follow-up for all ENGAGE registry patients in 2018. We discuss the evolving challenges for EVAR that the Endurant and other next-generation stent-grafts are designed to address and review outcomes published with the Endurant since the CE marking of the device in July 2008.
    No preview · Article · Jul 2011 · The Journal of cardiovascular surgery
Show more