Pulsatile distension of the proximal aneurysm neck is larger in patients with stent graft migration.

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.

van Keulen JW ，Moll FL ，Barwegen GK ，Vonken EP ，van Herwaarden JA ... -  《-》

The role of aortic neck dilation and elongation in the etiology of stent graft migration after endovascular abdominal aortic aneurysm repair with a passive fixation device.

Litwinski RA ，Donayre CE ，Chow SL ，Song TK ，Kopchok G ，Walot I ，White RA ... -  《JOURNAL OF VASCULAR SURGERY》

CT angiography in stent-graft sizing: impact of using inner vs. outer wall measurements of aortic neck diameters.

Iezzi R ，Dattesi R ，Pirro F ，Nestola M ，Santoro M ，Snider F ，Bonomo L ... -  《-》

The Relationship between Temporal Changes in Proximal Neck Angulation and Stent-Graft Migration after Endovascular Abdominal Aortic Aneurysm Repair.

In recent years, endovascular abdominal aortic aneurysm repair (EVAR) for treating abdominal aortic aneurysms (AAA) has become quite prevalent in Japan. Though little information is available about temporal changes in proximal neck angulation due to the difficulties encountered in measuring the angle. Therefore, we examined temporal changes in proximal neck angulation and its relationship to stent-graft migration after EVAR. Between June 2007 and March 2010, 159 patients underwent EVAR for treatment of fusiform AAAs at our hospital. This study focuses on the 80 patients among this group whose treatment sites and subsequent stent grafts were examined by contrast computed tomographic angiography before surgery, directly after surgery (within 4 days), as well as 1 year and 2 years thereafter. We created curved planar reconstruction (CPR) images and measured the length of migration and neck angle using our method. At 2 years after EVAR, the average length of proximal landing zone was 21.4 ± 9.2 mm. The average length of stent migration after 2 years was 1.41 ± 2.68 mm. The average neck angle was 33.9° preoperatively and 29.9° directly after surgery yielding a significant difference. However, 1 and 2 years after surgery the average neck angle was 28.2° and 28.4°, respectively. The number of patients experiencing a change >6° in the angle of the proximal neck between the preoperative condition and that directly after surgery was 16 (34.8%) with the use of Zenith stent grafts (n = 46) and 14 (41.2%) with the use of Excluder stent grafts (n = 34). There was no correlation between the proximal neck angle and migration of the proximal stent graft. In addition, there was no correlation between the changes in proximal neck angle and the secondary intervention rate and the occurrence of endoleak. There was a significant change in the neck angle between the preoperative condition and the immediate postoperative condition. However, there was no clear relationship found between the angle of the neck and the proximal stent-graft migration. Postoperative changes in the proximal neck angle just after EVAR and subsequent temporal changes during a 2-year follow-up period do not appear to predict stent-graft migration, secondary intervention rates, or the occurrence of endoleak.

Tokunaga S ，Ihara T ，Banno H ，Kodama A ，Sugimoto M ，Komori K ... -  《-》

Long-term influence of suprarenal or infrarenal fixation on proximal neck dilatation and stentgraft migration after EVAR.

We evaluated the influence of the proximal fixation systems of stentgrafts on proximal inter-renal or infrarenal aneurysm neck dilatation after endovascular repair of abdominal aortic aneurysms. Anatomic and clinical predictive factors of neck dilatation and stentgraft proximal migration were searched for. Taking account of a prospective and monocenter register, 58 patients' files, with a complete minimum 3-year follow-up, were analyzed after treatment with stentgrafts with a suprarenal fixation (SRF: 33 Talent) or an infrarenal fixation (IRF: 25 AneuRx). Both groups were compared in terms of inter-renal neck dilatation (D1: diameter between the two renal arteries), infrarenal neck dilatation (D2: 7-mm diameter under the lowest renal artery), and specific complication (proximal migration, endoleak). The diameter measured on the last control computed tomography scan was compared with the postoperative diameter. Neck dilatation was defined by a diameter increase exceeding 3 mm and by the proximal migration due to a caudal displacement of the stentgraft ≥10 mm. Predictive factors of proximal migration or neck dilatation were searched for (anatomy of the neck, aneurysm anatomy, stent graft oversize percentage, demographic factors). Preoperatively, both groups were comparable in terms of anatomic and demographic characteristics of the aneurysm. Mean follow-up was longer in the AneuRx group (62 ± 17 months vs. 53 ± 13 months, p = 0.045) and the percentage of stent graft oversize was greater in the Talent group (18 ± 6% vs. 13 ± 5%, p < 10(-4)). Freedom from a dilatation exceeding 3 mm in D1 and D2 did not bring any significant difference between the two groups. In each group, the remodeling of the aneurysmal sac (AneuRx median = -4 mm, Talent median = -5 mm, p > 0.05) was only moderately related to proximal neck remodeling. A small angulation of the neck and a smaller neck were the only predictive factors of neck dilatation found respectively in D1 (p = 0.007) and in D2 (p = 0.022). Stent graft proximal migration was more frequent in the AneuRx group (p = 0.031) and was more frequent with large aneurysms (p = 0.029). In the long term, the absence of proximal stent graft fixation system on the dilatation of the aneurysm proximal neck enhances proximal migration. Conversely, the inter-renal or infrarenal proximal neck dilatation does not depend on the type of proximal fixation but on anatomic factors and on the natural evolution of the aneurysmal disease.

Pintoux D ，Chaillou P ，Azema L ，Bizouarn P ，Costargent A ，Patra P ，Gouëffic Y ... -  《-》