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 ... -  《-》

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 ... -  《-》

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 ... -  《-》

Reintervention Rate after Open Surgery and Endovascular Repair for Nonruptured Abdominal Aortic Aneurysms.

We aim to determine the reintervention rate after open aortic aneurysm repair (OAR) or endovascular aneurysm repair (EVAR) according to compliance or noncompliance with the instructions for use (IFU) for commercial endovascular stent grafts. After exclusion of those with a ruptured abdominal aortic aneurysm (AAA) and isolated iliac artery aneurysm with or without a small AAA (diameter < 5 cm), 240 patients received OAR or EVAR for a nonruptured AAA between January 2006 and March 2016. EVAR was performed from October 2009. Patients were divided into 3 groups: OAR (n = 146), IFU EVAR (n = 42), and non-IFU EVAR (n = 52). Reintervention was defined as graft-related or laparotomy-related (with an abdominal incision after initial laparotomy) reoperations either during the index admission period or later. Final endoleak after EVAR was defined as persistent type I or III endoleak before exiting operating room after various procedures to eliminate the endoleak. There were 2 in-hospital deaths in the OAR group caused by reperfusion injury or pancreatitis. There was no in-hospital mortality in the EVAR group. Final endoleak was more common in non-IFU EVAR compared with IFU EVAR (17% vs. 0%; P = 0.004). The mean follow-up duration was 42.1 months, 25.3 months, and 25.0 months in the OAR, IFU EVAR, and non-IFU EVAR groups, respectively. Respective reintervention-free survival (RFS) rates at 1 and 3 years differed significantly by group: 97% and 95% in the OAR group, 100% and 96% in the IFU EVAR group, and 89% and 87% for non-IFU EVAR group (P = 0.043) with a higher reintervention rate in the non-IFU EVAR than in the OAR group. There was no significant difference in RFS rate between the OAR and IFU EVAR groups (P = 0.881). Overall survival (OS) rates at 1 and 3 years, respectively, were 94% and 78% in the OAR group, 90% and 86% in the IFU EVAR group, and 93% and 56% in the non-IFU EVAR group (P = 0.098). There were no significant differences between the OAR and IFU EVAR groups (P = 0.890). In contrast to IFU EVAR group, the RFS and OS rates of non-IFU EVAR group were lower than in the OAR group during mid-term follow-up. Final endoleak was more frequent, and reintervention was more commonly performed in the non-IFU group than in the IFU group. Therefore, performing EVAR in non-IFU situations should be planned carefully.

Hwang D ，Park S ，Kim HK ，Lee JM ，Huh S ... -  《-》

Editor's Choice - Late Open Surgical Conversion after Endovascular Abdominal Aortic Aneurysm Repair.

Late open surgical conversion following endovascular aneurysm repair (EVAR) may occur more frequently after performing EVAR in anatomy outside the instructions for use (IFU). This study reviews predictors and outcomes of late open surgical conversion for failed EVAR. This retrospective cohort study reviewed all EVARs performed at the Ottawa Hospital between January 1999 and May 2015. Open surgical conversions >1 month post EVAR were identified. Variables analysed included indication for conversion, pre-intervention AAA anatomy, endovascular device and configuration, operative technique, re-interventions, complications, and death. Of 1060 consecutive EVARs performed, 16 required late open surgical conversion. Endografts implanted were Medtronic Talent (n = 8, 50.0%), Medtronic Endurant (n = 3, 18.8%), Cook Zenith (n = 4, 25.0%), and Terumo Anaconda (n = 1, 6.2%). Eleven grafts were bifurcated (68.8%), five were aorto-uni-iliac (31.2%). The median time to open surgical conversion was 3.1 (IQR 1.0-5.2) years. There was no significant difference in pre-EVAR rupture status (1.4% elective, 2.1% ruptured, p = .54). Indications for conversion included: Type 1 endoleak with sac expansion (n = 4, 25.0%), Type 2 endoleak with expansion (n = 2, 12.5%), migration (n = 3, 18.8%), sac expansion without endoleak (n = 2, 12.5%), graft infection (n = 3, 18.8%), rupture (n = 2, 12.5%). Nine patients (56.2%) underwent stent graft explantation with in situ surgical graft reconstruction, seven had endograft preserving open surgical intervention. The 30 day mortality was 18.8% (n = 3, all of whom having had endograft preservation). Ten patients (62.5%) suffered major in hospital complications. One patient (6.5%) required post-conversion major surgical re-intervention. IFU adherence during initial EVAR was 43.8%, versus 79.0% (p < .01) among uncomplicated EVARs. Open surgical conversion following EVAR results in significant morbidity and mortality. IFU adherence of EVARs later requiring open surgical conversion is markedly low. More data are required to elucidate the impact of increasing liberalisation of EVAR outside of IFU.

Kansal V ，Nagpal S ，Jetty P 《-》