Midterm Results of Endovascular Aneurysm Repair Using the Endurant Stent-Graft According to the Instructions for Use vs. Off-Label Conditions

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.

Endovascular aneurysm repair offers a survival advantage and is cost-effective compared with conservative management in patients physiologically unfit for open repair

OBJECTIVE

The endovascular aneurysm repair-2 (EVAR-2) trial suggested that EVAR in patients unfit for open surgical repair (OSR) failed to provide a significant overall survival advantage compared with conservative management. The aim is to compare survival and cost-effectiveness in patients with poor cardiopulmonary exercise test (CPET) metrics who underwent EVAR or were managed conservatively.

METHODS

A prospective database of all CPETs (1435 patients) performed to assess preoperative fitness for abdominal aortic aneurysm repair was maintained. A total of 350 patients deemed unfit for OSR underwent EVAR or were managed conservatively. A 1:1 propensity-matched analysis incorporating age, gender, anaerobic threshold, and aneurysm size was used to compare survival. Cost-effectiveness analysis was based on the economic model for the National Institute for Health and Care Excellence clinical guideline on abdominal aortic aneurysm treatment.

RESULTS

Propensity matching produced 122 pairs of patients in the EVAR and conservative management groups. The median overall survival for the EVAR group was significantly longer than that for the conservative management group (84 vs 30 months, P < .001). One-, three-, and five-year mortality in the EVAR group was 7%, 40%, and 68%, respectively, compared with 25%, 68%, and 82% in the conservative management group, all P < .001. The increment cost-effectiveness ratio for EVAR was £8023 (US$11,644) per quality-adjusted life year gained compared with £430,602 (US$624,967) in the National Institute for Health and Care Excellence guideline, which is based on EVAR-2 results.

CONCLUSIONS

EVAR offers a survival advantage and is cost-effective in selected patients deemed unfit for OSR based on CPET compared with conservative management.

Preliminary outcomes of the LifeStream balloon-expandable stentgraft in Zenith Iliac branch device to preserve pelvic circulation: A Korean multicenter study

BACKGROUND

To evaluate early outcomes of aortoiliac or isolated iliac artery aneurysm repair using the Zenith® Bifurcated Iliac Side (ZBIS) stent graft combined with the LifeStream™ Balloon Expandable Vascular Covered Stent as a bridging stentgraft.

METHODS

Between August 2018 and February 2020, 38 patients (37 male, mean age 72.7 years) received 46 LifeStream stents in conjunction with 38 ZBIS stent grafts to bridge hypogastric arteries for aneurysm repair in six university hospitals in Korea. The primary outcomes were technical success rate and procedure-related complications. Secondary outcomes were bridging stent graft patency and re-intervention.

RESULTS

All procedures were performed as elective standard endovascular aortic aneurysm repair (EVAR) and unilateral iliac branch device (IBD). Mean follow-up was 13.1 months, and patient overall survival rate was 96.7%. Technical success rate was 76.3% (n = 29). Causes of failure included seven total endoleaks; six type Ic and one type IIIc from the IBD junction, one unintentional IIA coverage, and one failure to deploy the IIA stent graft. Procedure-related complications occurred in two patients: one LifeStream migration and one ZBIS stent graft migration. Overall patency rates for the LifeStream and ZBIS stents were 97.4% and 97.2%, respectively.

CONCLUSION

This multicenter preliminary experience with the LifeStream™ Balloon Expandable Vascular Covered Stent in IBD demonstrated good patency; however, an unexpectedly high rate of type Ic endoleaks was observed. Combined use of the LifeStream stent with the ZBIS stent graft is safe and feasible to preserve pelvic circulation with good patency and a low rate of device-related reintervention.

A meta-analysis of safety and efficacy of endovascular aneurysm repair in aneurysm patients with severe angulated infrarenal neck

Objectives

A growing number of abdominal aortic aneurysms with severe angulated neck anatomy is treated by endovascular means. However, contradictory early and late outcomes have been reported. Our review and outcome analysis attempted to evaluate the available literature and provide clinicians with a base for clinical implementation and future research.

Materials and methods

A systematic review of the literature was undertaken to identify the outcomes of endovascular aneurysm repair in patients with severe infrarenal neck angulation (SNA ≥ 60°) vs non-severe neck angulation (NSNA). Outcome measures included perioperative complications, type 1a endoleak, neck-related secondary procedures, stent graft migration, aneurysm rupture, increase (>5mm) in sac diameter, all-cause and aneurysm-related mortality (PROSPERO Nr.: CRD42021233253).

Results

Six observational studies reporting on 5981 patients (1457 with SNA and 4524 with NSNA) with a weighted mean follow-up period of 1.8 years were included. EVAR in SNA compared with NSNA was associated with a higher rate of type 1a endoleak at 30 days (4.0% vs 1.8%; p< 0.00001), at 1 year (2.8% vs 1.9%; p<0.03), at 2 years (4.9% vs 2.1%; p< 0.0002), at 3 years (5.6% vs 2.6%; p< 0.0001). The rate of neck-related secondary procedures was significantly higher at 1 year (6.6% vs 3.9%; p<0.05) and at 3 years (13.1% vs 9%; p<0.05). Graft migration, aneurysm sack increase, aneurysm rupture and all-cause mortality were not statistically different at mid-term.

Conclusions

The use of EVAR in severely angulated infrarenal aortic necks is associated with a high rate of early and mid-term complications. However, aortic related and all-causes mortality are not higher compared to patients with NSNA. Therefore, EVAR should be cautiously used in patients with SNA.

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.

Endovascular Aortic Repair with the "Step-by-Step" Deployment of the Endurant Stent-Graft System in Severe Neck Angulation: Technique and Review of the Literature

OBJECTIVES

To describe a new technique based on a different deployment of the Endurant Stent-Graft System (Medtronic Cardiovascular, Santa Rosa, CA) during endovascular aortic aneurysm repair to guarantee a more precise deployment in presence of severe neck angulation (SNA).

TECHNIQUE

The "step-by-step" deployment technique consists of an alternate partial release of the main body and of the free-flow suprarenal stents to approximate the radiopaque markers of the graft fabric to the aortic wall, obtaining a more precise delivery, reducing the possibility of downward dislodgments along the external curve of the infrarenal angle and asymmetrical deployments in presence of SNA.

CONCLUSIONS

The "step-by-step" technique is a simple, safe, and effective graft-deployment method, which allows a very precise release in SNA and possibly achieves better results in the long-term period in such difficult anatomies.

Endurant stent graft demonstrates promising outcomes in challenging abdominal aortic aneurysm anatomy

OBJECTIVE

We aimed to assess the 5-year safety and effectiveness outcomes of patients enrolled in the Endurant Stent Graft Natural Selection Global Post Market Registry (ENGAGE) who were treated outside the approved indications for use (IFU) of the Endurant stent graft.

METHODS

Our primary outcome measure was 12-month treatment success, defined as successful endograft delivery and deployment and the absence of type I or III endoleak, stent migration or limb occlusion, late conversion, and abdominal aortic aneurysm diameter increase or rupture. Secondary outcome measures included 30-day all-cause mortality, major adverse events, secondary procedures, technical observations, aneurysm-related mortality, and all-cause mortality within 12 months.

RESULTS

Demographic characteristics of ENGAGE patients treated outside (225 [17.8%]) and within (1038 [82.2%]) the IFUs were similar, except that female patients comprised a much higher percentage of the outside IFU group (19.1% vs 8.7%; P < .001). The outside IFU group presented with lower rates of coronary artery disease and cardiac revascularization and a greater number of symptomatic patients compared with the within IFU group (21.3% vs 15.0%; P = .020). Technical success was achieved in more than 99% of all patients. The outside and within IFU groups showed a comparable and low occurrence of uncorrected type I (0.9% vs 1.2%; P = 1.00) and type III endoleak (0.4% vs 0.3%; P = .54) immediately after device implantation. The 5-year freedom from type IA endoleaks was 89.4% vs 96.7% (P < .0001) for those patients outside and within the IFUs, respectively, although both groups had similar type III endoleaks through 5 years (P = .61). Stent graft limb occlusion estimated overall survival, and freedom from aneurysm-related mortality and endovascular interventions were comparable in both patient groups through the 5-year follow-up. The Kaplan-Meier estimates at 5 years showed a trend for low but increased need for type I or III endoleak correction procedures in the outside IFU group compared with the within IFU group (7.2% vs 5.2%; P = .099).

CONCLUSIONS

Differences were not observed in all-cause mortality, aneurysm-related mortality, and secondary procedures between within and outside IFU patients through a 5-year follow-up in the ENGAGE registry. Proximal necks with angulation or diameters outside the IFUs were the most common reasons for patients identified as being outside IFU, and the cohort had increased incidence of type IA endoleaks. Despite the challenges presented from the broad range of aortic and abdominal aortic aneurysm morphologies, the Endurant stent graft showed promising 5-year outcomes.

Fenestrated Endovascular Aneurysm Repair versus Snorkel Endovascular Aneurysm Repair: Competing yet Complementary Strategies

Juxtarenal/pararenal aortic aneurysms and type IV thoracoabdominal aneurysms pose particular technical challenges for endovascular repair as they involve the visceral segment in addition to insufficient infrarenal neck for the use of standard endovascular aneurysm repair (EVAR) devices. To overcome these challenges, complex EVAR techniques have been developed to extend the proximal landing zone cephalad with maintaining perfusion to vital aortic branches, thereby broadening the applicability of endografting from the infrarenal to the suprarenal aorta. Complex EVAR can be divided into two broad categories: fenestrated endovascular aneurysm repair (FEVAR) and snorkel EVAR. FEVAR is a valid procedure with the standardized procedure, although it remains as a relatively complex procedure with a learning curve. Given time constraints for the custom fenestrated graft, snorkel EVAR may be an alternative for complex repairs in symptomatic or ruptured patients for whom custom-made endografts may not be immediately available. This article discusses these two most commonly used complex EVAR strategies.

Large Diameter (≥29 mm) Proximal Aortic Necks Are Associated with Increased Complication Rates after Endovascular Repair for Abdominal Aortic Aneurysm

BACKGROUND

The aim of this study is to investigate the impact of proximal aortic diameter on outcome after endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs).

METHODS

This is a case-control (1:1) retrospective analysis of prospectively collected data on 732 AAA patients treated with EVAR in 2 university centers. Patients with an infrarenal neck diameter of 29-32 mm (wide neck, WN group) were compared with patients with a neck diameter of 26-28.9 mm (control group) matched for age, gender, and maximum aneurysmal sac diameter. Any patients treated outside the instructions for use of each endograft or with no adequate follow-up were excluded. The primary end point was any neck-related adverse event (a composite of type Ia endoleak, neck-related secondary intervention, and endograft migration) during follow-up.

RESULTS

Sixty-four patients with a proximal neck diameter of 29-32 mm (WN group) were compared with a matched control group of 64 patients with a neck diameter of 26-28.9 mm (control group). Oversizing was significantly higher in the study group (17.9% vs. 15.5%, P = 0.001). Overall median available follow-up was 24 months (range 12-84) (WN group 24 months vs. control group 18.5 months, P = 0.943). Primary end point was recorded in 8 patients (12.5%) of the WN group and in 1 patient (1.6%) of the control group. Freedom from the primary end point at 36 months (standard error <10%) was 87.3% for the study versus 98.4% for the control group (log rank = 4.66, P = 0.03). On multiple regression analysis, the presence of a proximal aortic neck >29 mm was the only independent risk factor for neck-related adverse events (odds ratio 7.4, 95% confidence interval 1.2-47.1).

CONCLUSIONS

EVAR in the presence of a wide proximal aortic neck is likely to be associated with higher adverse neck-related event rates and thus, in such cases closer follow-up may be required.

Cinical outcomes of Endurant II stent-graft for infrarenal aortic aneurysm repair: comparison of on-label versus off-label use

PURPOSE

We aimed to compare the outcomes of the Endurant II (Medtronic) stent-graft used under instructions for use versus off-label in high-risk patients considered unfit for conventional surgery.

METHODS

Data from patients treated with the Endurant II stent-graft between December 2012 and March 2015 were retrospectively analyzed. Sixty-four patients were included. Patients were assigned to group A if treated under instructions for use (n=34, 53%) and to group B if treated off-label (n=30, 47%). Outcome measures included perioperative mortality and morbidity, survival, freedom from reintervention, endoleak incidence, in-hospital length of stay, and mean stent-graft component used. Mean follow-up was 22.61±12 months (median, 21.06 months; range, 0-43 months).

RESULTS

One perioperative mortality (1.6%) and one perioperative complication (1.6%) occurred in group B. At two months follow-up, one iliac limb occlusion (1.6%) occurred in group A. No type I/III endoleaks were recorded. A type II endoleak was identified in three cases (4.7%). Overall survival at three years was 89% (97% for group A, 82% for group B; P = 0.428). Reintervention-free survival at three years was 97% for both groups (P = 0.991). A longer in-hospital stay was observed in group B (P = 0.012).

CONCLUSION

The Endurant II (Medtronic) new generation device was safe in off-label setting at mid-term follow-up. The off-label use of the Endurant II (Medtronic) is justified in patients considered unfit for conventional surgery. Larger studies are required in this subgroup of patients.

Preliminary experience with the Endurant II short form stent-graft system

BACKGROUND

The aim of this study was to evaluate our preliminary experience with the use of the Endurant II short form (IIs) stent-graft in the treatment of abdominal aortic aneurysms (AAAs).

METHODS

Between November 2014 and November 2015, 79 patients were consecutively treated with the Endurant IIs stent-graft at three European vascular centers. Early (30-day) results in terms of technical success, limb occlusion, major morbidity, and mortality were analyzed. Estimated 1-year outcomes in terms of survival, freedom from type I endoleak, freedom from limb occlusion, and freedom from any device-related reinterventions were assessed with Kaplan-Meyer method. Factors affecting 1-year freedom from type I endoleak were analyzed by log-rank test and by Cox regression test for multivariate analysis.

RESULTS

Intraoperative technical success was achieved in all cases. Thirty-day mortality was 1.3% (one death due to cardiac failure). Early type I endoleak was detected in three patients (3.8%). During the follow-up (mean duration 6.7 months; range 1-14), two type I endoleaks resolved spontaneously. No limb occlusions or aneurysm-related reinterventions were recorded. Estimated survival, freedom from type I endoleak, freedom from limb occlusions, and freedom from any device-related reinterventions rates at 1 year were 96%, 96.6%, 100%, and 100%, respectively. Adoption of chimney technique significantly affected 1-year freedom from type I endoleak (P≤0.001).

CONCLUSIONS

Preliminary use of the new Endurant IIs stent-graft is safe and effective in endovascular repair of AAAs (EVAR) without early limb occlusions. Further studies with larger population sizes and longer follow-up are needed to evaluate mid- and long-term results.

Fenestrated stent grafts for the treatment of complex aortic aneurysm disease: A mature treatment paradigm

The introduction of fenestrated stent grafts (SGs) to treat abdominal aortic aneurysms (AAAs) with short proximal necks began in 1999. Nowadays, the whole visceral aorta can be treated totally by endovascular means. The established use of fenestrated devices to treat complex AAAs as a first-line management option has been previously reported. An up-to-date evaluation of the literature was performed including all types of publications regarding the use of fenestrated technology to repair complex AAAs. Fenestrated repair is now an established alternative to hybrid/chimney/snorkel repairs. However, specific criteria and prerequisites are required for the use and improvement of this method. Multiple device morphologies have been used incorporating the visceral arteries in various combinations. This modular strategy connects different devices (bridging covered stents and bifurcated SGs) with the aortic main body, thus excluding the aneurysm from the circulation. Precise deployment of the fenestrated SG is mandatory for successful visceral vessel revascularization. Accurate SG sizing and customization, a high level of technical skill, and facilities with modern imaging techniques including 3D road mapping and dedicated hybrid rooms are required. Most experience has been with the custom-made Zenith Cook platform, although off-the-shelf devices have been recently implanted. More complex repairs have been performed over the last few years, but device complexity has also increased. Perioperative, mid-term, and a few recently reported long-term results are encouraging. Secondary interventions remain the main problem, similar to that observed after traditional endovascular abdominal aortic aneurysm repair (EVAR).

Current aortic endografts for the treatment of abdominal aortic aneurysms

Endovascular Aneurysm Repair is a widely adopted method of treatment for patients with abdominal aortic aneurysms. The minimally invasive approach offered with EVAR has become popular not only among physicians and patients, but in the medical device industry as well. Over the past 25 years the global market for aortic endografts has increased rapidly, resulting in a wide range of devices from various companies. Currently, there are seven endografts approved by the FDA for the treatment of abdominal aortic aneurysms. These devices offer a wide range of designs intended to increase inclusion criteria while decreasing technical complications such as endoleak and migration. Despite advances in device design, secondary interventions and follow-up requirements remain a significant issue. New devices are currently being studied in the U.S. and abroad and may significantly reduce complications and secondary interventions.

Outcomes of Endurant stent graft in narrow aortic bifurcation

OBJECTIVE

The purpose of this study was to compare the outcomes obtained with Endurant stent graft in the early and midterm period in the treatment of patients with narrow aortic bifurcation vs patients with standard aortic bifurcation.

METHODS

Data were prospectively collected from 817 patients with abdominal aortic aneurysm treated between November 2007 and August 2014 with the Endurant stent graft at our center. There were 87 patients (10.6%) with a narrow aortic bifurcation (≤20 mm; NA group). The remaining 730 patients (89.4%) had a standard aortic bifurcation (SA group). Early and estimated 3-year outcomes were evaluated in these patients in terms of survival, freedom from any device-related reinterventions, and freedom from graft thrombosis. Univariate and multivariate analyses in the NA group were performed to detect possible predictors for poor outcomes.

RESULTS

The two groups were similar in terms of demographics, preoperative diagnostic assessment, and intraoperative data. In 211 of 817 patients (25.8%), an adjunctive iliac limb stenting by balloon-expanding stents was performed. Overall, 41 patients in the NA group (47.1%) underwent iliac limb stenting, whereas an iliac stent was implanted in just 170 patients (23.3%) in the SA group (P < .001). The mean follow-up was 16.3 months (range, 1-73 months). The estimated 3-year survival rate was similar between the two groups (87.2% in the NA group vs 80.8% in the SA group; P = .84). Furthermore, the estimated freedom from any device-related reinterventions was 92.9% in the NA group and 85.5% in the SA group (P = .1). Finally, the estimated 3-year freedom from graft thrombosis was 96.9% in the NA group and 94.8% in the SA group (P = .79). In the NA group at univariate and multivariate analyses, none of the examined preoperative or intraoperative factors were independent predictors of poor outcomes.

CONCLUSIONS

Use of bifurcated Endurant stent graft, combined in almost half of the patients with narrow aortic bifurcation with additional aortoiliac stent placement, is feasible and safe. Early and midterm outcomes are similar to those obtained in non-narrow aortic bifurcation.