The Impact of Aneurysm Morphology and Anatomic Characteristics on Long-Term Survival after Endovascular Abdominal Aortic Aneurysm Repair.

Hostile anatomic characteristics in patients undergoing endovascular abdominal aortic aneurysm repair (EVAR) and the placement of endografts not in concordance with the specific device anatomic guidelines (or instructions for use [IFU]) have shown decreased technical success of the procedure. But these factors have never been evaluated in regard to patient postoperative survival. We sought to assess the association between survival and (1) aneurysm anatomy and characteristics and (2) implantation in compliance with manufacturer's anatomic IFU guidelines in patients undergoing endovascular aortic aneurysm repair. The cohort included 273 consecutive patients who underwent EVAR at Baylor Heart and Vascular Hospital between January 1, 2002 and December 31, 2009 and had their preoperative computed tomography (CT) scan digitally retrievable. The CT scans and operative notes were then reviewed, and the anatomic severity grading (ASG) score, maximum aneurysm diameter, thrombus width, patency of aortic side branch vessels, and implantation in compliance with IFU guidelines were assessed. The unadjusted association between survival (assessed until November 1, 2011) and these variables was assessed with the Kaplan-Meier method. Moreover, propensity-adjusted (for a comprehensive array of clinical and nonclinical risk factors) proportional hazard models were developed to assess the adjusted associations. Seven (2.56%) patients died within 30 days from EVAR, and 88 (30.04%) patients died during the study follow-up. Patient mean survival was 6.3 years. The unadjusted analysis showed a statistically significant association between survival and thrombus width (P = 0.007), ASG score (P = 0.004), and implantation in compliance with IFU guidelines (P = 0.007). However, the adjusted analysis revealed that none of the anatomic and compliance factors were significantly associated with long-term survival (ASG, P = 0.149; diameter, P = 0.836; thrombus, P = 0.639; patency, P = 0.219; and implantation compliance, P = 0.219). Unfavorable aneurysm morphologic characteristics and endograft implantation not in compliance with IFU guidelines did not adversely affect patient survival after EVAR in this group of patients. This implies that unfavorable anatomy, even that which would necessitate implantation of the EVAR device outside of the IFU guidelines, should not necessarily contraindicate EVAR.

Mahajan A ，Barber M ，Cumbie T ，Filardo G ，Shutze WP Jr ，Sass DM ，Shutze W Sr ... -  《-》

Any nonadherence to instructions for use predicts graft-related adverse events in patients undergoing elective endovascular aneurysm repair.

A variety of devices exist for endovascular aneurysm repair (EVAR). Device-specific instructions for use (IFU) detail anatomic constraints to application and deployment of devices and are developed from rigorous bench testing. Nonadherence to IFU occurs frequently to avoid open surgery. The purpose of this study was to determine if IFU violations are associated with increased risk of graft-related adverse events (GRAEs) during follow-up. This multicenter retrospective observational study included patients undergoing elective endovascular repair for abdominal aneurysmal disease with three different devices. Demographics, anatomic data, and follow-up data were collected on patients from 2005 to 2014. IFU violations were device specific and included neck diameter, length, and angulation and iliac artery diameter and length. GRAEs included a composite outcome of reintervention, migration, endoleak (type II excluded), rupture, limb occlusion, sac growth, and aneurysm-related mortality during the follow-up period. Kaplan-Meier survival and Cox proportional hazards modeling were performed. Any IFU violations as well as neck-specific IFU violations were analyzed. In 461 patients undergoing EVAR, 43.8% had at least one IFU violation. Patients with IFU violations were more likely to have peripheral vascular disease (12.4% vs 7.3%) and were less likely to be male (78.7% vs 90.3%). The most frequent IFU violations included diameter deviations of the neck (15.2%) and of the iliac artery (21.4%). Overall, the GRAE rate was 12.8%. Median follow-up time was 1.9 and 2.1 years for patients with and without an IFU violation, respectively. Kaplan-Meier survival revealed a significant association between the presence of an IFU violation and GRAEs (log-rank, P = .031). When adjusted for clinical variable through Cox hazard modeling, the association remained significant (hazard ratio 1.8; 95% confidence interval, 1.05-3.1). When neck-specific violations were considered independently, Kaplan-Meier survival (log-rank, P = .003) and Cox modeling (hazard ratio, 2.2; 95% confidence interval, 1.2-4.0) revealed a significant association between neck-specific IFU violation and GRAEs. A total of 43.8% of patients undergoing EVAR had a device-specific IFU violation, indicating that implanters are pushing the boundaries of device capabilities. Our study identified that any IFU violation was significantly associated with GRAEs over time. Caution should be applied to patients being considered for EVAR when IFU deviations exist.

Herman CR ，Charbonneau P ，Hongku K ，Dubois L ，Hossain S ，Lee K ，Steinmetz OK ... -  《-》

Anatomic characteristics of abdominal aortic aneurysms presenting with delayed rupture after endovascular aneurysm repair.

Endovascular aneurysm repair (EVAR) has become the mainstay of treatment for abdominal aortic aneurysms (AAAs) requiring repair. Delayed rupture after EVAR represents a rare but potentially fatal complication. The purpose of this study was to review the frequency and characteristics of patients presenting with secondary rupture and to define the relationship between rupture after EVAR and initial compliance with instructions for use (IFU). This is a retrospective study of a prospectively maintained database. Patients presenting with delayed rupture after EVAR were identified from January 2002 to December 2014. Medical records and imaging were reviewed to define anatomic characteristics and compliance with IFU criteria. Demographics, comorbidities, preoperative imaging, and long-term outcomes were analyzed. Patients were divided into two groups according to compliance with IFU criteria. Outcomes included type of repair (open vs secondary endovascular) as well as perioperative morbidity and mortality. A total of 3081 patients underwent EVAR for AAA from 2002 to 2014. Of the 3081 patients, 45 experienced delayed rupture after EVAR. The mean time interval between initial repair and rupture was 38 months. All patients with delayed ruptures had a type Ia endoleak. Mean follow-up after secondary repair was 44.1 months, and overall mortality was 6.7% (n = 3). Patients were divided in two groups according to compliance with IFU criteria: within the IFU and outside the IFU. There was no significant difference in comorbidities between the two groups except smoking, which was more frequent in the outside the IFU group (25% vs 21%; P = .03). Patients repaired outside the IFU had a higher incidence of type Ia endoleak before presenting with a rupture (44% vs 6%; P = .001), more frequently required open repair (44% vs 12%; P = .002), and had higher perioperative mortality (10.3% vs 0%; P = .01). On review of preoperative computed tomography scans, the outside the IFU group had larger aneurysm sac diameters (7.2 vs 5.6 cm; P = .04), larger proximal neck diameters (28 vs 24 mm; P = .01), shorter proximal necks (12 vs 21 mm; P = .007), and a higher degree of neck angulation >40 degrees (56 vs 11%; P < .001). Delayed rupture after EVAR is a rare but potentially fatal complication. In patients presenting with secondary rupture, EVAR performed outside the IFU was associated with higher perioperative mortality and need for open repair. Careful selection of patients based on AAA anatomy and adherence to the IFU criteria may reduce the incidence of delayed rupture.

Zacharias N ，Warner CJ ，Taggert JB ，Roddy SP ，Kreienberg PB ，Ozsvath KJ ，Sternbach Y ，Darling RC 3rd ... -  《-》

No major difference in outcomes for endovascular aneurysm repair stent grafts placed outside of instructions for use.

Studies have shown that a sizable percentage of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) is performed outside the instructions for use (IFU). We report our long-term outcomes after EVAR with respect to device-specific IFU. Computed tomography angiography data from a cohort of 566 patients meeting inclusion criteria who underwent elective EVAR between 2003 and 2014 were examined. Preoperative anatomic measurements for each patient were taken and compared with device-specific IFU. Primary outcomes included all-cause mortality and AAA-related mortality. Secondary outcomes were late-onset rupture, need for reintervention, endoleaks, aneurysm sac enlargement, and intraoperative and perioperative complications. Nine different stent grafts were placed in this set of patients with a mean follow-up of 3.54 ± 2.65 years. Most patients (465; 82.2%) were male, and the mean age was 74.8 ± 8.70 years. Overall, 176 patients (31.1%) fit all IFU anatomic criteria, and 535 patients (94.5%) fit at least half of IFU criteria. In patients, iliac artery diameter was most commonly outside of IFU (253; 44.7%). A total of 1114 iliac arteries were treated, with 463 (41.6%) treated outside of iliac artery diameter IFU; the majority of these (374; 80.7%) were larger than IFU. Demographics and comorbidities were comparable between the groups within and outside of IFU. AAA-related mortality and all-cause mortality were similar between these two groups, as was late-onset rupture, need for reintervention, rates of endoleak, aneurysm sac enlargement, and major intraoperative and perioperative complications. The sole statistically significant difference in secondary outcomes was increased perioperative blood transfusion needed in those treated outside the IFU, 13.2% vs 6.2% in those treated within IFU (P = .02); however, this was not associated with decreased access vessel diameter or iliac artery rupture. Despite most EVAR patients being treated outside of IFU, there was no difference in outcomes with respect to all-cause mortality or aneurysm-related mortality. In addition, with the exception of perioperative blood transfusions, there was no association between IFU adherence and late-onset rupture, need for reintervention, rates of endoleak, aneurysm sac enlargement, or most other major complications.

Beckerman WE ，Tadros RO ，Faries PL ，Torres M ，Wengerter SP ，Vouyouka AG ，Lookstein RA ，Marin ML ... -  《-》

Adherence to endovascular aortic aneurysm repair device instructions for use guidelines has no impact on outcomes.

Prior reports have suggested unfavorable outcomes after endovascular aortic aneurysm repair (EVAR) performed outside of the recommended instructions for use (IFU) guidelines. We report our long-term EVAR experience in a large multicenter registry with regard to adherence to IFU guidelines. Between 2000 and 2010, 489 of 1736 patients who underwent EVAR had preoperative anatomic measurements obtained from the M2S, Inc, imaging database (West Lebanon, NH). We examined outcomes in these patients with regard to whether they had met the device-specific IFU criteria. Primary outcomes were all-cause mortality and aneurysm-related mortality. Secondary outcomes were endoleak status, adverse events, reintervention, and aneurysm sac size change. The median follow-up for the 489 patients was 3.1 years (interquartile range, 1.6-5.0 years); 58.1% (n = 284) had EVAR performed within IFU guidelines (IFU-adherent group), and 41.9% (n = 205) had EVAR performed outside of IFU guidelines (IFU-nonadherent group). Preoperative anatomic data showed that 62.4% of the IFU-nonadherent group had short neck length, 10.2% had greater angulation than recommended, 7.3% did not meet neck diameter criteria, and 20% had multiple anatomic issues. A small portion (n = 49; 10%) of the 489 patients were lost to follow-up because of leaving membership enrollment (n = 28), moving outside the region (n = 10), or discontinuing image surveillance (n = 11). There was no significant difference in any of the primary or secondary outcomes between the IFU-adherent and IFU-nonadherent groups. Aneurysm sac size change at any time point during follow-up also did not differ significantly between the two groups. A Cox proportional hazard model showed that IFU nonadherence was not predictive of all-cause mortality (hazard ratio, 1.0; P = .91). Similarly, IFU nonadherence was not identified as a risk factor for aneurysm-related mortality or adverse events in stepwise Cox proportional hazards models. In our cohort of EVAR patients with detailed preoperative anatomic information and long-term follow-up, overall mortality and aneurysm-related mortality were unaffected by IFU adherence. In addition, rates of endoleak and reintervention after initial EVAR were similar, suggesting that lack of IFU-based anatomic suitability was not a driver of outcomes.

Walker J ，Tucker LY ，Goodney P ，Candell L ，Hua H ，Okuhn S ，Hill B ，Chang RW ... -  《-》