Aneurysm sac thrombus load predicts type II endoleaks after endovascular aneurysm repair.

Type II endoleaks are associated with the absence of aneurysm shrinkage after endovascular abdominal aortic aneurysm repair (EVAR). This study aims at determining the predictability of this complication, whose potential risk factors have been the subject of conflicting reports. Preoperative computed tomography (CT) scans of 178 patients who underwent EVAR for true infrarenal abdominal aortic aneurysms between January 20, and April 17, 2003, with a minimum follow-up of 30 days, were reviewed. The following information was retrieved: maximum aneurysm diameter, aneurysm thrombus load (maximum thickness, percentage of sac circumference wall coverage, percentage of maximum sac area occupancy); number, diameter, and nature (lumbar, inferior mesenteric, accessory renal, middle sacral) of patent aortic side-branch arteries; thrombus thickness at each aortic branch ostium, and aneurysm diameter at that level. Postoperative CT and duplex scans supplemented with angiography in selected cases were reviewed for the presence of a type II endoleak observable beyond the 30th postoperative day. Logistic regression was used to assess the association of each variable with this outcome. There were 38 (21.3%) patients with type II endoleaks after the 30th postoperative day. The median follow-up was 12 months (range 1-65 months). By univariate analysis, the following variables significantly decreased the risk of a type II endoleak: thrombus maximum thickness [odds ratio (OR) 0.77 for a 5 mm increase, p = 0.009], mean thrombus thickness at aortic side-branches ostia (OR 0.65 for a 1 mm increase, p = 0.0006), thrombus-occupied percentage of maximum aneurysm area (OR 0.72 for a 10% increase, p < 0.0001), percentage of thrombus-lined aneurysm wall (OR 0.53 for a 25% increase, p < 0.0001). The presence of a patent inferior mesenteric artery (OR 6.84, p < 0.01) and the number of patent aortic side-branches (OR 1.37 for each additional vessel, p = 0.002) significantly increased the risk of detecting a late type II endoleak. Aneurysm and aortic side-branch diameters did not have any impact. In a multiple logistic regression model (whole model p < 0.0001), the thrombus-occupied percentage of maximum aneurysm area (OR 0.74 for a 10% increase, p < 0.0005) and the number of patent aortic side-branches (OR 1.31 for each additional vessel, p = 0.009) remained independent predictors of type II endoleaks. The simple measure of the proportion of maximum aneurysm area occupied by thrombus may be a useful way to identify patients at high risk of a persistent type II endoleak. Patients with low preoperative sac thrombus load should be followed with a high degree of suspicion for this complication.

Proximal type I endoleak after endovascular abdominal aortic aneurysm repair: predictive factors.

Proximal type I endoleaks after endovascular abdominal aortic aneurysm repair (EVAR) are associated with a high risk of rupture. Risk factors for developing this complication are not fully elucidated. We aimed to define preoperative predictors for proximal type I endoleak and describe its clinical outcome. From a consecutive series of 257 patients who underwent EVAR, we selected 202 who had available pre- and postoperative CT scan studies. Proximal neck diameter, length, angulation, calcification, thrombus load (thickness, percentage of neck circumference coverage, percentage of neck area occupancy), and maximum aneurysm diameter were evaluated on preoperative CT scans. All postoperative CT and duplex ultrasound scans, supplemented with angiograms in selected cases, were reviewed for the presence or absence of endoleak. Device overlap and oversizing (relative to the proximal neck) were also determined. Type I proximal endoleak rates were estimated using the Kaplan-Meier method. The associations between the variables listed above and proximal type I endoleak were evaluated by use of Cox proportional hazards models. Proximal type I endoleak occurred in eight patients, corresponding to a 3-year incidence rate of 4% (SE = 1.5%). The median follow-up was 340 days (range, 22-1954). Univariate analyses found significant associations between proximal type I endoleak and the following variables: percentage of calcified neck circumference (hazards ratio = 2.19 for a 25% increase, p = 0.019), aneurysm maximum diameter (hazards ratio = 1.98 for a 1-cm increase, p = 0.006) and proximal neck and device overlap (hazards ratio = 0.53 for a 5-mm increase, p = 0.007). The mean overlap among cases with and without type I proximal endoleak was 15.6 mm and 29.3 mm, respectively. When these variables were included in a multivariate model, all remained statistically significant. No significant association could be documented for neck thrombus-related variables. Thirty-nine (19.3%) patients had a beta neck angle inferior to 120 degrees . There was a trend toward a higher incidence of proximal type I endoleaks in these patients (p = 0.057). Device oversize relative to proximal neck diameter did not affect the probability of this type of endoleak. One patient survived an emergency open repair of a ruptured aneurysm after significant expansion. Six patients underwent endovascular reinterventions (4 additional proximal cuff placements, 2 proximal angioplasties). The mean interval for reintervention was 389 days. Distal migration (>or=5 mm) was identified in four cases (50%). Proximal type I endoleak is a rare complication after EVAR, but it is associated with a high number of reinterventions and potentially serious consequences. Patients with short and heavily calcified aneurysmal necks and large aneurysms are at increased risk of proximal type I endoleaks.

Endovascular abdominal aortic aneurysm repair: does gender matter?

Substantial differences across genders have been documented for the natural history and clinical course of cardiovascular diseases. This study's objective is to compare preoperative characteristics, intraoperative events, and postoperative outcomes in men and women undergoing endovascular abdominal aortic aneurysm repair (EVAR). We hypothesized that despite gender anatomic specificities, EVAR may achieve similar results across genders. We included 241 consecutive patients who underwent elective EVAR at our institution from December 1996 through May 2003. Demographic variables and comorbidities were collected by chart review, and intraoperative events were from surgical notes. Baseline anatomic characteristics were evaluated on the last preoperative computed tomography (CT) scan. Radiologic outcomes were evaluated on all postoperative CT scans, and clinical follow-up information was abstracted from charts. Women constituted 12% (n = 29) of our cohort and were older than men (79.9 vs. 74.9 years, p = 0.0003). When compared to men, they had aneurysms with similar diameter (54.1 vs. 55.5 mm, p = 0.491) but narrower (23.1 vs 25.5 mm, p < 0.0001) and shorter (18.9 vs. 30.4 mm, p < 0.0001) proximal necks. Female iliac arteries were narrower (9.6 vs. 11.4 mm, p < 0.0001), with higher calcification scores (2.5 vs. 2.3, p = 0.047) but lower tortuosity indexes (1.2 vs. 1.3, p = 0.0001). Additional access maneuvers were more frequent in women: iliac access angioplasty (31% vs. 10.9%, = p = 0.007), uni-iliac conversion (13.8% vs. 1.4%, p = 0.005), and iliac "chimney" conduit (12.1% vs. 1.2%, p = 0.0001). There was a trend toward longer fluoroscopy time in women (34.6 vs. 26.9 min, p = 0.056). The following postoperative outcomes at 24 months were similar in women and men: freedom from endoleak (63.4% vs. 72.7%, p = 0.74), reintervention rate (28% vs. 24.5%, p = 0.878), aneurysm shrinkage (24.3% vs. 68.7%, p = 0.199), aneurysm expansion (0% vs. 3%, p = 0.213), and survival (92.9% vs. 84.3%, p = 0.341). There was a trend toward higher rates of neck dilation relative to preoperative diameter in women (48.5% vs. 16% at 12 months, p = 0.059) and toward lower limb patency rates in men (100% vs. 92.8%, p = 0.098). In sum, women have shorter proximal necks and smaller and more calcified iliac arteries, which increases the necessity of access-related additional maneuvers. Despite being older and having a less favorable anatomy, women can expect similar technical and clinical outcomes after EVAR.