Mid-term results of "off-label" use of the Endurant stentgraft in patients with infrarenal abdominal aortic aneurysms.

OBJECTIVES: EVAR is the preferred treatment modality for patients with an infrarenal abdominal aortic aneurysm with suitable anatomy. Each manufacturer of aortic stentgrafts has specific anatomic requirements. In some patients, it is not possible to adhere to the instructions for use, but alternative treatment is also not possible. In these patients, EVAR can be performed outside instructions for use. METHODS: In this study, all consecutive patients in whom an Endurant II or IIS stentgraft was used between 1 January and 31 December were reviewed. We compared the two patient groups in whom this stentgrafts was used outside and inside instructions for use. Patients with planned adjuvant therapy, for example, chimney procedure or iliac side branches, were excluded. RESULTS: In 74 of 178 (41.6%) patients, the instructions for use were not adhered. The main reason was pathology of the aortic neck. There were more patients with type IA endoleak, this difference was borderline significant (p = .06). There were more patients with limb occlusion in the early postoperative period, but at the end of the follow-up period, the incidence was comparable. Aneurysm-related mortality and all-cause mortality were comparable in both groups. CONCLUSION: In this study, real-life experience with the Endurant II and IIS stentgraft is described. Non-adherence with instructions for use was associated with a higher risk of endoleak type IA (p = .06). In the early postoperative period, there were more patients with limb occlusion; this finding was not observed anymore at the end of the follow-up period.

Long-term outcomes of the Endurant endograft in patients undergoing endovascular abdominal aortic aneurysm repair.

OBJECTIVE/BACKGROUND: To investigate the long-term outcomes after endovascular aneurysm repair (EVAR) in a real-world setting using the Endurant endograft (EG). METHODS: 184 EVAR candidates treated with the Endurant family EGs in a single vascular center were prospectively enrolled from January 2009 to December 2016. Kaplan-Meir estimates of long-term standardized primary and secondary outcome measures were performed. Per protocol, subgroup comparison analysis was performed in three groups: patients treated within instructions for use (in-IFU) vs patients treated outside IFU (outside-IFU), EVAR in patients receiving the Endurant proximal diameter 32 or 36 mm EG vs those receiving the <32 mm diameter EG and EVAR with various Endurant EG versions. RESULTS: The mean follow-up was 75.09 ± 37.9 months (range: 4.1-172 months). The median age of the patients was 72.96 ± 7.03 years (range: 55-88 years). A total of 177 patients were male (96.2%). Compliance with IFU was followed in 107 patients (58.2%). Overall survival was 69.5% and 48% at 5 and 8 years, respectively. Of the 102 all-cause deaths, 7 (6.9%) were aneurysm related. Six of these postimplant deaths occurred in patients presented with aneurysm rupture from type Ia or/and type Ib endoleak. At 5, 8, and 10 years of observation, freedom from aneurysm rupture, open surgical conversion, type I/III endoleak, any type of endoleak, aneurysm-related secondary intervention probabilities, and neck-related events were as follows: 98.1%, 95%, and 89.4%; 95.1%, 91.2%, and 85.7%; 93.6%, 87.3%, and 83.9%; 83.4%, 74%, and 70.9%; 89.8%, 76.7%, and 72%; and 96.3%, 90%, and 87.6%, respectively. Corresponding clinical success was 90%, 77.4%, and 68.4%, respectively. Patients treated outside-IFU had significantly higher risk of aneurysm rupture, open surgical conversion probability, occurrence of type I/III endoleak, and chance of reinterventions and lower clinical success probabilities compared with the in-IFU counterparts at 5 and 8 years. This statistical difference remained when type Ia endoleak or endoleak of any type was considered independently. In addition, it was stronger in patients having extreme anatomic boundaries (>1 hostile anatomic condition), when aneurysm-related death, aneurysm rupture, and clinical success at 5 years were considered. Overall proximal migration and limb occlusion were recorded in 1.1% and 4.9% of the patients, respectively. Overall reintervention rate was 17.4%. An increase in aneurysm sac diameter was observed in 12.5% of patients and was not related to IFU status. The Endurant version or the proximal EG diameter had no significant association with the chance of any complication or adverse event. CONCLUSIONS: The data confirmed the durability of the Endurant EG, achieving promising long-term outcomes in a real-world setting. However, its positive performance must be interpreted with caution in patients treated off-label especially those with extreme anatomic boundaries. In this cohort, some of EVAR advantages might be lost in the late future. Further similar studies are warranted.

Multicenter Comparative Analysis of Late Open Conversion in Patients With Adherence and Nonadherence to Instructions for Use Endovascular Aneurysm Repair.

PURPOSE: The widespread adoption of endovascular aneurysm repair (EVAR) as preferred treatment modality for abdominal aortic aneurysm (AAA) has enlarged the number of patients needing open surgical conversion (OSC). The relationship between adherence to Instructions For Use (IFU) and EVAR long-term outcomes remains controversial. The aim of this study is to compare preoperative differences and postoperative outcomes between EVAR patients not adjusted to IFU and adjusted to IFU who underwent OSC. METHODS: This multicenter retrospective study reviewed 33 explanted EVARs between January 2003 and December 2019 at 14 Vascular Units. Patients were included if OSC occurred >30 days after implantation and excluded if explantation was performed to treat an endograft infection, aortic dissection, or traumatic transections. Variables analyzed included baseline characteristics, adherence to IFU, implant and explant procedural details, secondary reinterventions, and postoperative outcomes. RESULTS: Fifteen explanted patients (15/33, 45.5%) were identified not accomplished to IFU (out-IFU) at initial EVAR vs 18 explanted patients adjusted (in-IFU). During follow-up, a mean of 1.73±1.2 secondary reinterventions were performed, with more type I endoleaks treated in the subgroup out-IFU: 16.7% vs 6.3% in-IFU patients and more type III endoleaks (8.3% vs 0%). Patients out-IFU had shorter mean interval from implant to explant: 47.60±28.8 months vs 71.17±48. Type II endoleak was the most frequent indication for explantation. Low-flow endoleaks (types II, IV, V) account for 44% of indications for OSC in subgroup of patients in-IFU, compared with 13.3% in patients out-IFU and high-flow endoleaks (types I and III) were the main indication for patients out-IFU (33.3% vs 16.7% in-IFU). Total endograft explantation was performed in 57.5% of cases (19/33) and more suprarenal clamping was required in the subgroup out-IFU. Overall, 30-day mortality rate was 12.1% (4/33): 20% for patients out-IFU and 5.6% in-IFU. CONCLUSIONS: In our experience, type II endoleak is the most common indication for conversion and differences have been found between patients treated outside IFU with explantation taking place earlier during follow-up, mainly due to high-flow endoleaks and with higher mortality in comparison with patients adjusted to IFU. Ongoing research is required to delve into these differences.

Long-term outcomes of endovascular aneurysm repair according to instructions for use adherence status.

OBJECTIVE: Endovascular aneurysm repair (EVAR) has become the standard treatment for abdominal aortic aneurysms (AAAs). Endovascular device manufacturers have defined specific anatomic criteria for the aneurysm characteristics that should be observed as instructions for use (IFU) for specific grafts. In clinical practice, the prevalence of performing EVAR outside the IFU has been high. In the present study, we aimed to determine the effects of nonadherence to the IFU on the outcomes. METHODS: Patients who had undergone EVAR for an infrarenal AAA between 2005 and 2013 were included. IFU nonadherence was defined as any violation of device-specific IFU criteria and was compared with IFU adherence. The primary outcomes were all-cause mortality, aneurysm-related mortality, AAA rupture, graft-related adverse events (GRAEs), including limb-related adverse events, and type Ia endoleaks. A second aim was to study whether the prevalence of EVAR performed outside the IFU has increased over time. RESULTS: A total of 258 patients were included, 144 (55.8%) of whom had been treated according to the IFU and 114 (44.2%) outside the IFU. In the IFU nonadherence group, all-cause mortality (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.02-1.89; P = .037) and aneurysm-related mortality (HR, 5.1; 95% CI, 1.4-18.6; P = .015), and the incidence of AAA rupture (HR, 5.4; 95% CI, 1.1-26.6; P = .036) and GRAEs (HR, 1.7; 95% CI, 1.1-2.8; P = .025). No significant association was found between the incidence of type Ia endoleaks and neck-related IFU or limb-related adverse events and iliac-related IFU. However, neck length was a risk factor for type Ia endoleaks (HR, 18.2, 95% CI, 6.3-52.2; P < .001), aneurysm-related mortality (HR, 8.7; 95% CI, 1.8-41.6; P = .007), AAA rupture (HR, 21.7; 95% CI, 2.8-166; P = .003), and GRAEs (HR, 4.4; 95% CI, 2.0-9.7; P < .001). An IFU violation regarding neck angulation was also a risk factor for all-cause mortality (HR, 2.0; 95% CI, 1.1-3.7; P = .032), aneurysm-related mortality (HR, 7.6; 95% CI, 1.4-42.8; P = .021), AAA rupture (HR, 79.4; 95% CI, 6.3-999; P = .001), and GRAEs (HR, 4.3; 95% CI, 1.9-9.5; P < .001). The prevalence of EVAR performed outside the IFU did not increase over time. CONCLUSIONS: Performing EVAR outside the IFU had a negative effect on outcomes, including all-cause mortality, aneurysm-related mortality, AAA rupture, and GRAEs. Neck angulation and neck length seemed to be the most crucial aneurysm characteristics.

The association between device instructions for use adherence and outcomes after elective endovascular aortic abdominal aneurysm repair.

OBJECTIVE: Aortic neck anatomy has a significant impact on the complexity of endovascular aortic aneurysm repair (EVAR), with concern that neck characteristics outside of the instructions for use (IFU) may result in worse outcomes. Therefore, this study determined the impact of neck characteristics outside of the IFU on perioperative and 1-year outcomes and mid-term survival after EVAR. METHODS: We identified all patients undergoing elective infrarenal EVAR from December 2014 to May 2020 in the Vascular Quality Initiative database. Neck characteristics outside of the IFU were determined based the specific device IFU neck characteristics (neck diameter, length, and angulation). Patients without 1-year follow-up were excluded for the 1-year outcomes analyses (n = 6138 [40%]). We used multivariable adjusted logistic regression and Cox proportional hazard models to identify the independent associations between neck characteristics outside of the IFU and our outcomes. RESULTS: Of the 15,448 patients identified, 22.1% had neck characteristics outside of the IFU, including 6.6% with a infrarenal angle, 6.8% with a neck length, 10.4% with a neck diameter, and 1.1% with a suprarenal angulation outside of the IFU. Of these, 2.4% had more than one neck characteristic outside of the IFU. Patients with neck characteristics outside of the IFU were more often female (27.9% vs 15.0%; P < .001) and were older (median age, 75 years vs 73 years; P < .001). EVAR patients with neck characteristics outside of the IFU had higher rates of type Ia endoleaks at completion (4.8% vs 2.5%; P < .001), perioperative mortality (1.2% vs 0.6%; P < .001), 1-year sac expansion (7.1% vs 5.3%; P = .017), and 1-year reinterventions (4.4% vs 3.2%; P = .03). In multivariable adjusted analyses, neck characteristics outside of the IFU were independently associated with type Ia completion endoleaks (OR, 1.6; 95% CI, 1.3-2.0; P < .001), perioperative mortality (OR, 1.8; 95% CI, 1.2-2.7; P = .005), 1-year sac expansion (OR, 1.4; 95% CI, 1.0-1.8; P = .025), and 1-year reinterventions (OR, 1.4; 95% CI, 1.0-1.9; P = .039). The unadjusted midterm survival was lower for patients with neck characteristics outside of the IFU than for patients without (5-year survival 84.0% vs 86.7%; log-rank P < .001). However, after adjustment, survival was similar for patients with neck characteristics outside of the IFU to those within (hazard ratio, 1.1; 95% CI, 1.0-1.3; P = .22). CONCLUSIONS: Neck characteristics outside of the IFU are independently associated with completion type Ia endoleaks, perioperative mortality, 1-year sac expansion, and 1-year reinterventions among patients undergoing elective EVAR. These results indicate that continued effort is needed to improve the proximal seal in patients with neck characteristics outside of the IFU undergoing EVAR. Also, in patients with severe hostile neck characteristics, alternative approaches such as open repair, use of a fenestrated or branched device, or endoanchors should be considered.

A cross-sectional study on the anatomic feasibility of iliac side branch grafts in a real-world setting.

OBJECTIVE: The aim of this cross-sectional, single-center study was to analyze the feasibility of different commercially available iliac branch devices in Europe in a cohort of patients with aorto-iliac aneurysms. METHODS: All patients with aorto-iliac or iliac aneurysms that required iliac aneurysm repair, between 2017 and 2021, were included. Morphologic data was analyzed using computed tomography angiograms. The main outcome was the feasibility of each endoprosthesis (Cook ZBIS, Gore Iliac Branch Endoprosthesis [IBE], and JOTEC E-Iliac) according to the manufacturer's instructions for use. Secondary outcomes were feasibility in all three devices, in any device, and with adjunctive procedures (liberal criteria). Additionally, a comparative analysis of all three grafts was performed to analyze differences in feasibility. RESULTS: Overall, 119 iliac aneurysms in 101 patients were included. The mean age was 71 ± 11 years, and 91.6% were male. Feasibility was 52.9% for Cook ZBIS, 33.6% for Gore IBE, and 26.9% for the JOTEC E-Iliac device. A total of 65.5% of patients were feasible with at least one device, whereas only 10.1% complied with all three devices. The main reasons for lack of feasibility were a short common iliac artery length (Cook ZBIS), a narrow common iliac artery diameter (Gore IBE), and a >50° angulation between the external and internal iliac arteries (JOTEC E-Iliac). There was a significant difference between the feasibility of the three devices (P < .001). Cook ZBIS was the graft with the higher feasibility, with 3.3 and 4.4 higher odds when compared with Gore IBE and JOTEC E-Iliac devices, respectively. There was no significant difference between the Gore IBE and the JOTEC E-Iliac. By using liberal criteria, the overall feasibility increased to 95.8%. CONCLUSIONS: We found that only 65.5% of patients were feasible with one of the available devices according to the manufacturer's instructions for use. The Cook ZBIS was the device with the overall highest feasibility. Extending the use of these devices with adjunctive measures and a more liberal approach increased feasibility to 95.8%.

Editor's Choice - Endurant Stent Graft in Patients with Challenging Neck Anatomy "One Step Outside Instructions for Use": Early and Midterm Results from the EAGLE Registry.

OBJECTIVE: The aim of the Endurant for Challenging Anatomy: Global Experience (EAGLE) registry is to evaluate prospectively the technical and clinical success rate of a stentgraft used in patients with challenging neck anatomy outside the instructions for use (IFU) but within objective anatomical limits. METHODS: This was a prospective, international, multicentre, observational study. From 1 February 2012 to 1 September 2017, patients with an abdominal aortic aneurysm with a challenging infrarenal neck that were deemed suitable for endovascular aneurysm repair were included prospectively at 23 European centres. Patients were distributed by anatomy into three groups: short neck (SN; infrarenal neck 5 - 10 mm in combination with suprarenal angulation [α] ≤ 45° and infrarenal angulation [ß] ≤ 60°); medium neck (MN; infrarenal neck 10 - 15 mm with α ≤ 60° and ß 60° - 75° or α 45°- 60° and ß ≤ 75°; and long angulated neck (LN; infrarenal neck ≥ 15 mm with α ≤ 75° and ß 75°- 90° or α 60°- 75° and ß ≤ 90°. All computed tomography scans were reviewed by an independent core laboratory. Primary outcomes were technical and clinical success. Secondary endpoints were peri-operative major adverse events, all cause mortality, aneurysm related mortality, endoleaks, migration, and secondary intervention. RESULTS: One hundred and fifty patients (81.3% male) were included (SN = 55, MN = 16, LN = 79). The median follow up was 36 ± 12.6 months. In the overall cohort, the technical success rate was 93.3%. Estimated freedom from aneurysm related death was 97.3% at three years. Freedom from secondary interventions was 84.7% at three years. Estimated clinical success was 96.0%, 90.8%, and 83.2% at 30 days, one year, and three years, respectively. Estimated freedom from all cause mortality, late type IA endoleak, and migration at three years was 75.1%, 93.7%, and 99.3%, respectively. CONCLUSION: The early and midterm results of the EAGLE registry show that endovascular repair with the Endurant stentgraft in selected patients with challenging infrarenal neck anatomy yields results in line with large "real world" registries. Long term results are awaited for more definitive conclusions.

Adherence to instruction for use after endovascular repair of popliteal artery aneurysm.

OBJECTIVES: Endovascular repair (ER) of popliteal artery aneurysm (PAA) is an alternative to open repair. However, there is no standardized protocol for when to opt for ER and the decision is therefore at the discretion of the clinician. This study aims to evaluate the adherence to the Instruction For Use (IFU) in patients undergoing ER for PAA and factors associated with stent graft patency at one year. METHODS: The adherence to IFU provided by the manufacturer in 55 patients treated with Gore Viabahn® Endoprosthesis with Heparin Bioactive Surface for PAA between 2009 and 2019 were retrospectively analyzed. Duplex follow-up was performed at 30 days and one year. RESULTS: The two groups of patients treated within (n = 10) and not within (n = 45) IFU did not differ in patient demographics, diagnostic assessment, treatment or outcome. Forty-five patients (81.8%) received stent graft placement with at least one deviation according to IFU. Distal oversizing >20% was the most frequent deviation against IFU (n = 22, 40.0%). Primary patency at one year was 72%. Diameter size difference >1 mm between overlapping stent grafts (6/14 [43%], p = 0.013) and renal insufficiency (5/12 [42%], p = 0.0086) were associated with lower primary patency at one year. Age-adjusted analysis of tortuosity index (HR 1.78/SD, 95% CI 1.17-2.71; p = 0.0071) and maximal PAA angle (HR 1.73/SD, 95% CI 1.018-2.95; p = 0.043) were associated with major amputation/mortality at end of follow-up. CONCLUSION: The majority of patients undergoing ER for PAA were not treated within IFU. Diameter size difference >1 mm between overlapping stent grafts was associated with a higher loss of primary patency at one year. Multi-center studies with larger sample size and long-term follow up of patency are warranted.

Comparison of treatment options for aortic necks outside standard endovascular aneurysm repair instructions for use.

OBJECTIVE/BACKGROUND: Endovascular aneurysm repair (EVAR) is associated with worse outcomes in patients whose anatomy does not meet the device instructions for use (IFU). However, whether open surgical repair (OSR) and commercially available fenestrated EVAR (Zenith Fenestrated [ZFEN]) represent better options for these patients is unknown. METHODS: We identified all patients without prior aortic surgery undergoing elective repair of abdominal aortic aneurysms with neck length ≥4 mm at a single institution with EVAR, OSR, and ZFEN. We applied device-specific aneurysm neck-related IFU to EVAR patients, and a generic EVAR IFU to ZFEN and OSR patients. Long-term outcomes were studied using propensity scores with inverse probability weighting. We compared outcomes in patients undergoing EVAR by adherence to IFU and outcomes by repair types in the subset of patients not meeting IFU. RESULTS: Of 652 patients (474 EVAR, 34 ZFEN, 143 OSR), 211 had measurements outside of standard EVAR IFU (109 EVAR [23%], 27 ZFEN [80%], and 74 OSR [52%]). Perioperative mortality was 0.5% overall. For EVAR, treatment outside the IFU was associated with significantly higher adjusted rates of long-term type IA endoleak (22% at 5 years compared to 2% within IFU, hazard ratio [HR]: 5.8 [3.1-10.9], P < .001), and lower survival (5- and 10-year survival: 56% and 34% vs 81% and 53%, HR: 2.3 [1.2-4.3], P = .01). There was no difference in reinterventions or open conversion. In patients not meeting IFU, ZFEN was associated with higher adjusted rates of reinterventions (EVAR as referent: HR: 2.6 [1.5-4.4, P < .001), whereas OSR and EVAR patients experienced similar reintervention rates (HR: 0.7 [0.4-1.1], P = .13). Patients outside the IFU experienced lower mortality with OSR compared with either EVAR (HR: 0.4 [0.2-0.9], P = .005) or ZFEN (HR: 0.3 [0.1-0.7], P = .002). When restricted to patients outside the IFU deemed fit for open repair, OSR patients remained associated with lower adjusted mortality compared with ZFEN (HR: 0.2 [0.1-0.5], P < .001), but statistical significance was lost in the comparison to EVAR (HR: 0.6 [0.3-1.1], P = .1). CONCLUSIONS: Treatment outside device-specific IFU is associated with adverse long-term outcomes. Open surgical repair is associated with higher long-term survival in patients who fall outside of the EVAR IFU and should be favored over EVAR or ZFEN in suitable patients. A three-vessel-based fenestrated strategy may not be a durable solution for difficult aortic necks, but more data are needed to evaluate the performance of newer, four-vessel devices.

Outcomes of thoracic endovascular aortic repair in thoracic aortic aneurysm and penetrating aortic ulcer using the Conformable Gore TAG within and outside the instructions for use.

OBJECTIVE: To describe the outcome of thoracic endovascular aortic repair (TEVAR) in thoracic aortic aneurysm and penetrating aortic ulcer with respect to instructions for use status. METHODS: Between October 2009 and September 2017, a total of 532 patients underwent TEVAR; of which 195 have been treated using the Conformable GORE® TAG® thoracic endoprosthesis (CTAG). Fifty-six patients of this cohort underwent TEVAR for thoracic aortic aneurysm/penetrating aortic ulcer using the CTAG. Depending on the preoperative computed tomography angiography findings, patients were classified as inside or outside the device's instructions for use. All inside instruction for use patients underwent postoperative reclassification regarding the instructions for use status. Study endpoints included TEVAR-related reintervention, exclusion of the pathology (endoleak type I/III), TEVAR-related mortality, and graft-related serious adverse events. The median duration of follow-up was 29.7 months (range: 0-109.4 months). RESULTS: Of the 56 patients, 17 were primarily classified as outside instruction for use, and in additional 13 patients, TEVAR was performed outside instruction for use, leading to 30 outside instruction for use patients (53.6%). Twenty-six patients (46.4%) were treated inside instruction for use. Reintervention-free survival was lower in outside instruction for use patients (P = 0.016) with a hazard ratio of 9.74 (confidence interval 1.2-80.2; P = 0.034) for TEVAR-related reintervention. With respect to endoleak type I/III, relevant difference was detected between inside/outside instruction for use status (P = 0.012). The serious adverse event rate was 30.4%, mainly in outside instruction for use patients (P = 0.004). Logistic regression analysis indicated an association between graft-related serious adverse event/instructions for use status (odds ratio 6.11; confidence interval 1.6-30.06; P = 0.012). In-hospital death was seen more frequently in outside instruction for use patients (P = 0.12) as was procedure-related death (log-rank test: P = 0.21). CONCLUSION: TEVAR for thoracic aortic aneurysm/penetrating aortic ulcer is frequently performed outside instruction for use despite preoperative inside instruction for use eligibility, leading to important consequences for technical/clinical outcome. Instructions for use adherence in TEVAR should be of interest for further large-scale studies.

Prognosis review and time-to-event data meta-analysis of endovascular aneurysm repair outside versus within instructions for use of aortic endograft devices.

BACKGROUND: Our objective was to investigate whether patients undergoing standard endovascular aneurysm repair (EVAR) outside the instructions for use (IFU) have worse outcomes than patients treated within IFU. METHODS: We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Electronic bibliographic sources were searched up to January 2019 using a combination of controlled vocabulary (thesaurus) and free-text terms to identify studies comparing outcomes of EVAR in patients treated outside versus within IFU. Pooled estimates of dichotomous outcomes were calculated using odds ratio (OR) or risk difference (RD) and 95% confidence interval (CI). We conducted a time-to-event data meta-analysis using the inverse-variance method and reported the results as summary hazard ratio (HR) and associated 95% CI. Random-effects methods of meta-analysis were applied. We formed meta-regression models to explore heterogeneity as a result of changes in practice over time. RESULTS: We identified 17 observational cohort studies published between 2011 and 2017, reporting a total of 4498 patients. The pooled prevalence of EVAR performed outside the IFU was 40% (95% CI, 33-48). Nonadherence to IFU was not associated with increased risk of perioperative mortality (RD, 0.01; 95% CI, -0.00 to 0.01; P = .23), aneurysm rupture (HR, 1.34; 95% CI, 0.30-5.93; P = .70), aneurysm-related mortality (HR, 0.88; 95% CI, 0.20-3.84; P = .86), technical failure (RD, 0.01; 95% CI, -0.03 to 0.05; P = .56), requirement for adjunctive procedures (OR, 1.48; 95% CI, 0.81-2.71; P = .20), type I endoleak (HR, 2.28; 95% CI, 0.58-8.91; P = .24), aneurysm sac expansion (HR, 0.86; 95% CI, 0.55-1.33; P = .49), or aneurysm-related reintervention (HR, 1.04; 95% CI, 0.81-1.34; P = .74). The overall mortality was significantly higher in patients treated outside the IFU (HR, 1.20; 95% CI, 1.02-1.42; P = .03). Meta-regression showed that the prevalence of EVAR performed outside the IFU has increased over time (P = .019). CONCLUSIONS: Standard EVAR outside the IFU was not found to have worse aneurysm-related outcomes than treatment within the IFU. Standard EVAR outside the IFU could be considered in selected patients who are deemed high risk for complex open or endovascular surgery.

Outcome comparison of thoracic endovascular aortic repair performed outside versus inside proximal landing zone length recommendation.

OBJECTIVE: Success of thoracic endovascular aortic repair (TEVAR) relies heavily on the proximal landing zone (PLZ) sealing. Most instructions for use of thoracic endografts recommend a PLZ length of at least 2 cm. Because of the complex aortic anatomic features, TEVAR landing in zone 1 to zone 3 may not meet this requirement. The aim of this study was to examine whether 2-cm PLZ nonadherence was related to adverse outcomes after TEVAR. METHODS: A retrospective review was performed of patients who underwent zone 1, zone 2, and zone 3 landing TEVAR at a single institution between November 2013 and October 2018. Preoperative and postoperative computed tomography angiography images were analyzed using three-dimensional reconstruction. The patients were categorized into two groups: PLZ ≥2 cm (adherence group) and PLZ <2 cm (nonadherence group). Collected data included patient and anatomic characteristics. Primary outcomes were type IA endoleak, retrograde dissection, and graft migration. RESULTS: The cohort comprised 63 patients (18 in the adherence group and 45 in the nonadherence group) with a mean age of 53.3 ± 20.6 years. Indications for TEVAR were blunt thoracic aortic injury (65.1%), thoracic aneurysm (23.8%), penetrating ulcer (9.5%), and type B dissection (1.6%). Mean PLZ length was significantly shorter for the nonadherence group (8 ± 7 mm for the nonadherence group vs 34 ± 15 mm for the adherence group; P < .0001). PLZ location (2 zone 1, 15 zone 2, 46 zone 3) and oversizing (19.4% ± 8.3% for the adherence group; 20.3% ± 10.2% for the nonadherence group; P = .7) were similar between the groups. The mean PLZ aortic diameter of the adherence group was significantly larger than that of the nonadherence group (29 ± 5 mm for the adherence group; 25 ± 5 mm for the nonadherence group; P = .004). Mean follow-up time was 126.7 days (range, 0-644 days) for the adherence group and 233.8 days (range, 0-1750 days) for the nonadherence group (P = .2). During the study period, no primary outcome was observed in the adherence group, whereas 12 adverse events occurred in 10 patients in the nonadherence group (type IA endoleak, n = 10; graft migration, n = 1; retrograde dissection, n = 1). Of 10 type IA endoleaks, five were immediate (4 resolved spontaneously, 1 remained persistent) and five were delayed (1 resolved spontaneously, 1 remained persistent, 1 ruptured causing death, 2 required total arch replacement). CONCLUSIONS: Achieving recommended sealing zone of 2-cm centerline length is paramount to avoid device-related adverse outcomes. We recommend careful surveillance in patients undergoing urgent TEVAR with <2-cm PLZ.

Systematic Review and Meta-Analysis of Outcomes of Open and Endovascular Repair of Ruptured Abdominal Aortic Aneurysm in Patients with Hostile vs. Friendly Aortic Anatomy.

OBJECTIVE: To investigate the effect of hostile aortic anatomy on the outcomes of endovascular and open repair for ruptured abdominal aortic aneurysm (AAA). METHODS: Electronic bibliographic sources (MEDLINE, EMBASE, CENTRAL) were searched using a combination of thesaurus and free text terms to identify studies comparing treatment outcomes of ruptured AAA in patients with hostile vs. friendly aortic anatomy. A systematic review was conducted that conformed to the PRISMA guidelines using a registered protocol (CRD42019127307). The primary outcomes were peri-operative mortality, freedom from aneurysm related mortality, and overall survival. Pooled estimates of dichotomous outcomes were calculated using odds ratio (OR) and 95% confidence interval (CI). A time to event data meta-analysis was conducted using the inverse variance method and the results were reported as summary hazard ratio (HR) and associated 95% CI. Subgroup analysis for type of treatment (endovascular aneurysm repair [EVAR] or open repair) was undertaken. Random effects models of meta-analysis were developed. RESULTS: Ten observational studies were included reporting a total of 1284 patients (748 with hostile anatomy and 536 with friendly anatomy). Patients with hostile anatomy had a higher peri-operative mortality than patients with friendly anatomy (OR 1.73, 95% CI 1.13-2.66; p = .01). Subgroup analysis showed a significant difference in peri-operative mortality in favour of friendly anatomy in patients treated by EVAR (OR 1.76, 95% CI 1.01-3.08; p = .05), but not in those treated by open repair (OR 1.37, 95% CI 0.83-2.27; p = .22). Patients with hostile anatomy treated by EVAR had a significantly higher hazard of death in follow up than patients with friendly aortic anatomy (HR 2.01, 95% CI 1.18-3.44, p = .01), whereas for open surgical repair, the survival was similar in patients with hostile and those with friendly aortic anatomy (HR 0.90, 95% CI 0.61-1.32, p = .58). CONCLUSION: Hostile aortic anatomy is associated with increased mortality in patients with ruptured AAA treated by EVAR.

Aneurysm Growth After Endovascular Sealing of Abdominal Aortic Aneurysms (EVAS) with the Nellix Endoprosthesis.

OBJECTIVE: The aim of this study was to measure the incidence of post endovascular aneurysm sealing (EVAS) abdominal aortic aneurysm (AAA) growth, and its association with stent migration, in a cohort of patients with differing compliance to old and new Instructions For Use (IFU). METHODS: A retrospective single centre study was conducted to review the computed tomography (CT) and clinical data of elective, infrarenal EVAS cases, performed as a primary intervention, between December 2013 and March 2018. All included patients had a baseline post-operative CT scan at one month and at least one year follow up. The primary outcome measure was the incidence of AAA growth and its association with stent migration. AAA growth was defined as a ≥5% increase in aortic volume between the lowermost renal artery and the aortic bifurcation post EVAS at any time during follow up, in comparison to the baseline CT scan. Migration was defined according to the ESVS guidelines, as > 10 mm downward movement of either Nellix stent frame in the proximal zone. RESULTS: Seventy-six patients were eligible for inclusion in the study (mean age 76 ± 7.4 years; 58 men). AAA growth was identified in 50 of 76 patients (66%); adherence to IFU did not affect its incidence (mean growth within IFU-2016 compliant cohort vs. non-compliant: 16% vs. 13%, p = .33). Over time, the incidence of AAA growth increased, from 32% at one year to 100% at four years. AAA growth by volume was progressive (p < .001), as its extent increased over time. Migration was detected in 16 patients and there was a statistically significant association with AAA growth (13 patients displayed migration and AAA growth, p = .036). CONCLUSION: Patients treated with EVAS are prone to AAA growth, irrespective of whether their aortic anatomy is IFU compliant. AAA growth by volume is associated with stent migration. Clinicians should continue close surveillance post EVAS, regardless of whether patients are treated within IFU.

Five Year Results of the French EPI-ANA-01 Registry of AnacondaTM Endografts in the Treatment of Infrarenal Abdominal Aortic Aneurysms.

OBJECTIVE: A significant decrease in aneurysm related survival is observed at long term follow up after infrarenal endovascular aneurysm repair (EVAR) compared with open repair. Therefore, longer term results with new generation endografts are essential. The aim of this post-approval French multicentre prospective observational study (EPI-ANA-01) was to evaluate the technical success and five year mortality and secondary intervention rates of the third generation AnacondaTM endograft. METHODS: From June 2012 to October 2013, 176 consecutive unruptured infrarenal abdominal aortic aneurysms were included (160 male patients, mean age 75.3 ± 8.4 years). Survival, freedom from type Ia endoleak, limb events, and re-interventions were estimated using the Kaplan-Meier method. Anatomical and clinical characteristics were compared according to the occurrence of migration, conversion, adverse limb events, endoleak, and sac enlargement. RESULTS: The primary technical and clinical success rates were 98.3% and 94.9%, respectively. A hostile neck was identified in 33.9% of patients and 10.7% were treated outside instructions for use (IFU). An early post-operative (≤30 days) mortality rate of 1.7% was observed. At one and five years, respectively, the overall survival rate was 94.9% and 65.9% (aneurysm related in four patients [2.3%]) and the clinical success rate was 90.9% and 70.6%. Secondary interventions were performed in 35 of 176 patients (19.9%). The overall limb occlusion rate was 7.9% and the aneurysm sac diameter decreased significantly (pre-operative diameter 53.9 ± 8.6 mm vs. 42.3 ± 14.7 mm at five years; p < .001). Patients treated outside the instructions for use (IFU) had significantly higher rates of migration, surgical conversion, and aneurysm sac expansion (p = .03). CONCLUSION: The Anaconda endograft provides high technical success and satisfactory five year aneurysm exclusion and clinical success rates. However, implantation outside the IFU should be avoided, as it leads to significantly worse outcomes, and caution over the risk of limb occlusion and distal embolisation should be observed.

A new "angle" on aortic neck angulation measurement.

OBJECTIVE: Infrarenal aortic neck angulation is one of the most powerful predictors of endovascular aneurysm repair failure. Whereas the "gold standard" to measure this angle is three-dimensional (3D) reconstruction and centerline measurement, many surgeons rely on estimations of angulation based on two-dimensional (2D) views of computed tomography imaging. Unfortunately, these views do not accurately represent the true angle, particularly if aortic angulation is oblique to the standard views. In response to this issue, our group has developed a novel trigonometric formula that uses coronal and sagittal measured angles to calculate the true angle. The purpose of this study was to compare the paired angle formula with 3D centerline measurements for estimating true aortic neck angulation. METHODS: Fifty randomly selected patients treated by endovascular aneurysm repair at The Ottawa Hospital between 2010 and 2015 were studied. The 3D centerline aortic neck angle measurements were made by a radiology staff physician. The paired angle formula was applied by a vascular surgeon, resident, and student using 2D coronal and sagittal angles from computed tomography imaging to estimate the true angle. RESULTS: The average age was 78 years; 74% of patients were male, and average preoperative aneurysm diameter was 5.7 cm. The mean neck length was 1.9 cm (1.1-3.2 cm), and mean neck angulation calculated by the gold standard measurements was 39 degrees (2-84 degrees). Linear regression demonstrated strong association between 3D measurements and the paired angle formula, with correlations comparable to the intraobserver variability (intraclass correlation coefficient values range, 0.74-0.87). The average user estimates deviated minimally from the gold standard (absolute difference, 6 degrees; 95% confidence interval, 4-8 degrees) without systemic bias. The paired angle formula accurately ruled out severe angulation >60 degrees with an overall negative predictive value of >99%. Compared with isolated 2D measurements, application of the paired angle formula significantly decreased the false-negative rate of unappreciated severe angulation >60 degrees from 4.8% to 0.7% (P = .032). CONCLUSIONS: The paired angle formula detects significantly more severe angles than isolated 2D measurements and can accurately rule out severe angulation >60 degrees compared with the 3D measurements. The implementation of this angle estimation method is a useful adjunct in the measurement of aortic neck angulation, especially if 3D reconstruction software is not readily available. Furthermore, the importance of accurate angle measurement is not limited to vascular surgery and has direct relevance to any procedural specialty that relies on preoperative angle measurements.

Incidence and Treatment of Limb Occlusion of the Anaconda Endograft After Endovascular Aneurysm Repair.

PURPOSE: To evaluate the incidence and treatment of limb occlusions of the second- and third-generation Anaconda endografts. METHODS: A single-center retrospective study was conducted involving 317 consecutive patients (mean age 76 years; 289 men) who underwent endovascular aneurysm repair for elective asymptomatic, symptomatic intact, and ruptured infrarenal abdominal aortic aneurysm with 2 versions of the Anaconda device. From September 2003 to July 2011, the second-generation device was used in 189 patients (mean age 77 years; 169 men) and from July 2011 to September 2015, the third-generation device was implanted in 128 patients (mean age 75 years; 120 men). The rates of limb occlusion were compared between groups and according to compliance with the instructions for use (IFU); predictors were sought in multivariate analysis. The results of the latter are given as the hazard ratio (HR) and 95% confidence interval (CI). RESULTS: Kaplan-Meier freedom of occlusion estimates for second- and third-generation devices, respectively, was 96.6% and 95.0% at 1 year, 89.9% and 95.0% at 2 years, and 86.5% and 88.6% at 5 years. There was no significant difference in overall occlusion rate between the second-generation devices (p=0.332) or with regard to use within the IFU (p=0.827); however, there was a clinically relevant decrease in the occlusion rate for elective patients treated with the third-generation device (6.4% vs 13.1%, p=0.077). There was an increase in the occlusion rate when the iliac limb diameter was ≤13 mm. In multivariate analysis, the only independent predictor of limb occlusion was a small distal prosthesis diameter (HR 0.732, 95% CI 0.63 to 0.86, p<0.001). Symptomatic nonruptured and ruptured abdominal aortic aneurysm (AAA) interventions had an almost 2-fold increased risk of occlusion (HR 1.95, 95% CI 0.93 to 4.11, p=0.078), though this did not reach statistical significance. CONCLUSION: The Anaconda design has proven effectiveness in AAA exclusion in daily practice inside the IFU. However, efforts could be made to further reduce the limb occlusion rate.

Expanded Suitability of Ruptured Abdominal Aortic Aneurysms for Total Endovascular Repair Using the Endurant Endograft and Heli-FX EndoAnchors.

PURPOSE: To assess if the suitability of endovascular aneurysm repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs) can be expanded by combining the Endurant stent-graft with the Heli-FX EndoAnchors. MATERIALS AND METHODS: Contrast-enhanced computed tomography (CT) scans of 90 patients (mean age 73.2±9 years; 87 men) with RAAA admitted between January 2014 and January 2018 in 2 tertiary care centers were analyzed in a 3-dimensional workstation. Anatomical features of the aneurysms according to the instructions for use (IFU) for the Endurant endograft were evaluated and expansion of treatment with Heli-FX EndoAnchors was assessed. RESULTS: Neck length <10 mm was present in 41 (45.6%) patients; 5 had neck diameters outside the IFU and 45 (50.0%) had conical necks. Thrombus and calcium were absent in 63 (70.0%) and 73 (81.1%), respectively. In the study cohort, 44 (48.9%) patients met all the neck criteria, although overall IFU compliance was found in only 35 (38.9%) patients due to iliac-related issues in 21 patients. The adjunctive use of EndoAnchors in the entire study group would enhance the therapeutic range to an additional 24 patients, 8 of whom would need an associated iliac procedure. This represents an expansion of the total EVAR approach from 48.9% to 75.6% of cases if some iliac issues are overcome and from 38.9% to 56.7% without correcting iliac deficiencies. CONCLUSION: The main reason of being unfit for endovascular treatment in this series was neck length <10 mm. Based on this analysis, nearly 40% of RAAA patients would have been candidates for EVAR based on the IFU neck criteria for the Endurant stent-graft. This suitability could be nearly doubled with the use of EndoAnchors and correction of unsuitable iliac anatomy. The use of EndoAnchors has the potential to offer a significant benefit in the endovascular treatment of RAAA patients.

Stent Frame Movement Following Endovascular Aneurysm Sealing in the Abdominal Aorta.

PURPOSE: To investigate the incidence and extent of stent frame movement after endovascular aneurysm sealing (EVAS) in the abdominal aorta and its relationships to aneurysm growth and the instructions for use (IFU) of the Nellix endograft. METHODS: A retrospective single-center study was conducted to review the clinical data and computed tomography (CT) images of 75 patients (mean age 76±7.6 years; 57 men) who underwent infrarenal EVAS and had a minimum 1-year follow-up. The first postoperative CT scan at 1 month and the subsequent scans were used to measure the distances between the proximal end of the stent frames and a reference visceral vessel using a previously validated technique. Device migration was based on the Society of Vascular Surgery definition of >10-mm downward movement of either Nellix stent frame in the proximal landing zone; a more conservative proximal displacement measure (downward movement ⩾4 mm) was also recorded. Patients were categorized according to adherence to the old (2013) or new (2016) Nellix IFU. Aneurysm diameter was measured for each scan; a change ⩾5 mm was deemed indicative of aneurysm growth. RESULTS: Over a median follow-up of 24 months (range 12-48), proximal displacement ⩾4 mm occurred in 42 (56%) patients and migration >10 mm in 16 (21%), with similar incidences in the right and left stent frames. Proximal displacement was significantly more frequent among patients whose anatomy did not conform to any IFU (p=0.025). Presence of aneurysm growth ⩾5 mm was observed in 14 (19%) patients and was significantly associated with proximal displacement ⩾4 mm (p=0.03). CONCLUSION: Infrarenal EVAS may be complicated by proximal displacement and migration, particularly when performed outside the IFU. The definition of migration used for endovascular aneurysm repair may be inappropriate for EVAS; a new consensus on definition and measurement technique is necessary.

Two-Year Outcomes of the Nellix EndoVascular Aneurysm Sealing System for Treatment of Abdominal Aortic Aneurysms.

PURPOSE: To analyze the 2-year outcomes of endovascular aneurysm sealing (EVAS) according to 2 versions of the instructions for use (IFU). METHODS: A retrospective study was conducted involving 355 consecutive patients treated with the first-generation EVAS device from April 2013 to December 31, 2015, at 3 high-volume centers. Out of 355 patients treated with EVAS, 264 were elective asymptomatic infrarenal EVAS procedures suitable for analysis. In this cohort, 168 (63.3%) patients were treated within the IFU 2013 criteria; of these 48 (18.2%) were in compliance with the revised IFU 2016 version. RESULTS: Overall technical success was 98.2% (165/168) in the IFU 2013 group and 97.9% (47/48) in the IFU 2016 subgroup (p=0.428). The 2-year freedom from reintervention estimates were 89.7% (IFU 2013) and 95.7% (IFU 2016), with significantly more reinterventions in the first 45 cases (p=0.005). The stenosis/occlusion estimates were 6.5% (IFU 2013) and 4.2% (IFU 2016; p=0.705). Nine (5.4%) endoleaks (8 type Ia and 1 type Ib) were observed within the IFU 2013 cohort; 3 (2.1%) were in the IFU 2016 subgroup (p=0.583). Migration ≥10 mm or ≥5 mm requiring intervention was reported in 12 (7.1%) patients in the IFU 2013 cohort but none within the IFU 2016 subgroup. Ten (6.0%) patients demonstrated aneurysm growth in the IFU 2013 cohort, of which 2 (4.2%) were in the IFU 2016 subgroup. Overall survival and freedom from aneurysm-related death estimates at 2 years were 90.9% and 97.6% in the IFU 2013 cohort (IFU 2016: 95.5% and 100.0%). The prevalence of complications seemed lower within IFU 2016 without significant differences. CONCLUSION: This study shows acceptable 2-year results of EVAS used within the IFU, without significant differences between the 2 IFU versions, though longer follow-up is indicated. The refined IFU significantly reduced the applicability of the technique.