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 ... -  《-》

Coupling bifurcated stent-grafts to overcome anatomic limitations of endovascular repair of abdominal aortic aneurysms.

To evaluate the effectiveness of the coupling stent-graft technique and outcomes on contrast-enhanced computed tomography (CT). All patients who underwent endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) between 2007 and 2010 at a single institution were retrospectively analyzed. Of the 161 cases, 19 patients who had coupling stent-grafting because of AAA proximal neck angulation greater than 60°, conical neck, or iliac tortuosity were included. Patient age ranged from 62 to 87 years (mean, 73.3 y). Mean follow-up was 18.7 months (range, 1-36 mo). The coupling stent-graft technique was defined by the use of suprarenal fixation device main bodies (Zenith or Talent) with one or more EXCLUDER limbs to adapt tortuous and angulated iliac arteries. Pretreatment contrast-enhanced CT was analyzed based on three-dimensional and multiplanar reformatted images. Follow-up contrast-enhanced CT was also analyzed. Mean aneurysm diameter was 68.9 mm ± 14.0, neck length was 32.7 mm ± 15.1, and neck angulation was 68.9° ± 11.5. Conical neck shapes were present in four patients (21.1%) and ruptured AAAs were present in two (10.5%). Among 38 iliac arteries, the mean iliac artery tortuosity index was 1.52 ± 0.27 and iliac angle was 106.8° ± 18.1. Three patients (15.8%) underwent repeat intervention: placement of a balloon-expandable stent in the proximal neck for type I endoleak (n = 1), endovascular embolization for proximal type I endoleak (n = 1), and percutaneous approach following endovascular embolization for type II endoleak (n = 1). No type III endoleak, limb occlusion, limb kinking, or stent-graft migration developed. The coupling stent-graft technique is technically feasible, with acceptable midterm outcomes in EVAR of AAA in patients with unfavorable neck and iliac anatomies.

Lee M ，Lee DY ，Kim MD ，Lee MS ，Park SI ，Won JY ，Choi D ，Ko YG ... -  《-》

Impact of the Repositionable C3 Excluder System on the Endovascular Treatment of Abdominal Aortic Aneurysms With Unfavorable Neck Anatomy.

To analyze the midterm clinical outcomes among patients with favorable and unfavorable neck morphology for endovascular aneurysm repair (EVAR), specifically the impact of the repositionable C3 Excluder stent-graft on type I endoleak in patients with unfavorable neck. A retrospective review was conducted of 249 patients (mean age 74.3 years; 241 men) who underwent successful EVAR from January 2000 to December 2014 using either the traditional Excluder (n=140) or the C3 repositionable system (n=109). Unfavorable proximal aortic neck anatomy was defined by length <15 mm, angulation >60°, >50% circumferential thrombus, or >50% neck calcification. By these criteria, unfavorable neck anatomy was present in 71 (28.5%) patients (41 traditional Excluder and 30 C3 Excluder). The main endpoint was the incidence of type Ia endoleak and the need for a proximal cuff according to the type of neck anatomy. Comparisons between groups are reported as the odds ratio (OR) and 95% confidence interval (CI). A proximal extension cuff for type Ia endoleak was needed in 4 (2.2%) patients with favorable neck anatomy compared to 7 (9.9%) patients with unfavorable neck (OR 4.76, 95% CI 1.3 to 16.8, p=0.014). Among the patients with unfavorable neck, a proximal cuff was implanted in 6/41 (14.6%) traditional Excluder stent-grafts vs 1/30 (3.3%) in the C3 Excluder group (OR 4.39, 95% CI 0.55 to 34.58, p=0.23). Median follow-up was 30.5 and 38 months for favorable vs unfavorable neck groups, respectively (p=0.29). Only 1 case of type Ia endoleak was registered at 6.5 years' follow-up (traditional Excluder), with no device migration. Both Excluder stent-grafts provide good midterm clinical outcomes after EVAR in patients with unfavorable neck anatomy. Investigation of a larger cohort will be needed to identify if the C3 Excluder device offers any improvement over the traditional Excluder in terms of freedom from endoleaks.

Hernández Mateo MM ，Martínez López I ，Revuelta Suero S ，Marqués de Marino P ，Cernuda Artero I ，Cabrero Fernández M ，Serrano Hernando FJ ... -  《-》

One-year multicenter results of 100 abdominal aortic aneurysm patients treated with the Endurant stent graft.

The Endurant (Medtronic, Minneapolis, Minn) is a new stent graft specifically designed to make more patients anatomically eligible for endovascular aneurysm (EVAR). This study presents the 1-year results of 100 consecutive patients with abdominal aortic aneurysms (AAAs) treated with the Endurant stent graft in real-life practice. All clinical preoperative, operative, postoperative, and 1-year follow-up data of patients with the Endurant stent graft from three tertiary centers were prospectively collected. Patients underwent computed tomographic angiography (CTA) preoperatively, at 1 month, and at 1-year post-EVAR. The first 100 patients with an implantation date at least 1 year before our date of analysis and complete information were included. Clinical data, AAA characteristics, presence of endoleaks, graft migration, and other EVAR-related complications were noted. All values are stated as mean ± SD (range). This study included 100 patients with AAAs (88 men) with a mean age of 73 ± 8 years (47 to 87 years), an AAA size of 61 ± 10 mm (31 to 93 mm), an AAA volume of 210 ± 122 mL (69 to 934 mL), a proximal neck length of 33 ± 14 mm (9 to 82 mm), and an infrarenal angulation of 44 ± 25° (0°-108°). Nineteen of the 100 included patients had at least one anatomic characteristic that was considered a violation of the instructions for use (IFU) of the Endurant stent graft. A primary technical success was achieved in 98% of the patients (one additional stent placement in renal artery was required; one unplanned aorto-uni-iliac device placed), with no primary type I or III endoleaks or conversions. A secondary technical success was achieved in all cases. The 30-day mortality was 2% and the first postoperative CTA documented 16 endoleaks (16%; 16 type II). One-year follow-up showed three iliac limb occlusions (3%), one infected stent graft (causing a type Ia endoleak), and five endovascular reinterventions (5%; three to treat iliac limb occlusions, one proximal extension cuff; and one stent in the renal artery). The 1-year all-cause mortality rate was 12% (12 patients) and the AAA-related mortality was 3%. The mean AAA size was significantly smaller after 1 year (diameter, 54 ± 11.8 [32-80] mm; P < .01; volume, 173 ± 119 [42-1028] mL; P < .01), and one graft migration >5 mm and 13 endoleaks were noted (12 type II, 1 type I [neck dilatation]). The treatment of patients with AAAs with the Endurant stent graft seems to be successful and durable during the first year after EVAR. Despite the wider inclusion criteria for the Endurant, and with 19% of our patients treated outside the IFU, the AAA-related mortality, number of type I or III endoleaks, and reintervention rates are comparable to the results of other stent grafts.

van Keulen JW ，de Vries JP ，Dekker H ，Gonçalves FB ，Moll FL ，Verhagen HJ ，van Herwaarden JA ... -  《-》

Neck diameter and inner curve seal zone predict endograft-related complications in highly angulated necks after endovascular aneurysm repair using the Aorfix endograft.

Many studies have found that preoperative aneurysm anatomy can determine the postoperative complication rates for endovascular aneurysm repair (EVAR). With continual improvement in endograft technology, patients with challenging anatomy are increasingly able to undergo successful treatment with EVAR. This study aimed to quantify the influence of proximal neck anatomy on contemporary outcomes in a cohort of abdominal aortic aneurysm patients with highly angulated aneurysm necks. The study included 205 patients originally enrolled in the Prospective Aneurysm Trial: High Angle Aorfix Bifurcated Stent Graft (PYTHAGORAS) trial, the largest study to date to enroll patients with aortic aneurysm neck angles >60 degrees. Anatomic parameters included measurements of the proximal aneurysm neck as well as seal zones modeled in preoperative computed tomography scans. Follow-up up to 5 years postoperatively was available, for which stent-related complications (defined as sac expansion, stent migration, and type Ia endoleak) were assessed. Predictive anatomic parameters were assessed by Cox regression models, and a final multivariate model was created to predict complications. The cohort was also stratified by neck diameter for further comparison of complication rates. Of 205 patients enrolled in the trial, 67 stent-related complications occurred in 36 patients (17.6%) at 5 years after EVAR. Median follow-up was 48 months. Demographic and medical comorbidities did not predict risk of complications, nor did proximal neck length or neck angle. Independent predictors of post-EVAR complications included increasing proximal neck diameter (hazard ratio, 1.14; 95% confidence interval, 1.03-1.27; P < .05) and decreasing seal zone inner curve length (hazard ratio, 1.03; 95% confidence interval, 1.01-1.06; P < .05), which yielded a fair discriminatory utility (concordance, 0.67). Stratification by median neck diameter of 22.5 mm yielded two groups; patients with larger aortic necks (mean diameter, 24.8 ± 2.1 mm) had a 21.8% complication rate vs 12.6% in patients with smaller necks (mean diameter, 20.1 ± 1.6 mm; P < .05). Proximal aortic neck diameter and the seal zone inner curve length were found to be the best predictors of complications related to Aorfix (Lombard Medical, Oxfordshire, United Kingdom) in this population with highly angulated neck anatomy. Modeled seal zones are better able than traditional measurements to capture the limitations of a short, angled neck. These findings may inform preoperative risk stratification and planning in patients with hostile aortic neck anatomy undergoing EVAR.

Wang S ，Hicks CW ，Malas MB 《-》