Three-Year Results of the Endurant Stent Graft System Post Approval Study

doi:10.1016/j.avsg.2017.12.017

Annals of Vascular Surgery

Volume 50, July 2018, Pages 202-208

https://doi.org/10.1016/j.avsg.2017.12.017 Get rights and content

Background

Long-term data following endovascular aneurysm repair (EVAR) exist but are limited to endografts that are no longer in use. The aim of the ENGAGE Post Approval Study is to describe the long-term safety and effectiveness data following EVAR using the Endurant stent graft system.

Methods

From August 2011 to June 2012, 178 patients were enrolled and treated with the Endurant stent graft system. Clinical and radiologic data were prospectively collected and analyzed. The primary end point was abdominal aortic aneurysm (AAA)-related mortality, and secondary end points were overall mortality, endoleak, secondary interventions, and device-related complications. Kaplan-Meier estimates were used for late outcomes.

Results

A total of 178 patients underwent EVAR with the Endurant stent graft across 24 centers (82% men; median age 71, interquartile range [IQR] 66–79). Median aortic diameter was 55 mm (IQR 51–58 mm). There was a 98.9% technical success rate. Three-year clinical and radiographic follow-up data were available for 87% and 74% of patients, respectively. Median follow-up was 37 months (IQR 30–38 months). Three-year aneurysm-related mortality rate was 1.1%, with 2 deceased patients in the perioperative period. All-cause mortality rate at 3 years was 13%. No patients suffered from aneurysm rupture or underwent conversion to open repair through 3 years of follow-up. Only 11 patients (6.2%) had undergone reintervention at 3 years. Younger age was associated with reintervention (HR 3.3 per younger decade, 95% confidence interval 1.3–7.6, P < 0.01), but neck diameter, length, and angulation were not significantly associated with reintervention.

Conclusions

The Endurant stent graft system provides a safe, durable approach to treating infrarenal AAA. No patients experienced late rupture or aneurysm-related mortality, and only 1 in 16 patients underwent reintervention by 3 years. The rate of reintervention with the Endurant graft appears to be lower than other contemporary grafts, despite more liberal “Instructions For Use” parameters, but further research including direct graft comparisons will be necessary to guide appropriate graft selection.

Introduction

Endovascular aneurysm repair (EVAR) has become the predominant treatment of abdominal aortic aneurysms (AAAs) in patients who are anatomically suitable.1, 2 Designs of stent grafts are continuously evolving, with devices now tolerating aneurysm neck anatomy previously considered unsuitable for endovascular treatment of AAA. However, late rupture remains a significant problem after EVAR, with recent follow-up data from Medicare beneficiaries and randomized trials showing significantly higher rates of rupture and mortality following EVAR compared with open repair after 2–4 years.3, 4

Reducing complications and reinterventions while safely treating more patients with difficult anatomy is the current challenge in the endovascular treatment of AAA. The Endurant stent graft (Medtronic Cardiovascular, Santa Rosa, CA) is a new-generation graft designed to expand EVAR applicability in the setting of challenging AAA anatomy, especially to treat short infrarenal aortic neck length and to minimize long-term reinterventions. The Endurant Stent Graft Natural Selection Global Post-Market Registry (ENGAGE) previously evaluated the real-world global experience with the Medtronic graft, which was shown to be safe and effective up to 1 year.⁵ However, long-term results are still poorly characterized. A previous study of the Endurant stent graft for AAA demonstrated a low AAA-related mortality at 4-year follow-up; importantly, however, 20% of the patients did not meet the Instructions For Use (IFU), and therefore, the results may not accurately represent the performance of the Endurant stent graft.⁶

The Endurant graft received US Food and Drug Administration approval in December 2010, at which point the ENGAGE Post Approval Study (ENGAGE PAS) began to evaluate real-world experience with the graft in accordance with its IFU. The aim of the ENGAGE PAS is to provide the first detailed clinical description of early and late outcomes following approval of the Medtronic Endurant Stent Graft System in the United States.

Section snippets

Methods

The ENGAGE PAS protocol was approved by each study site institutional review board and is registered on clinicaltrials.gov (NCT01379222). All study patients consented to participate in the ENGAGE PAS.

Results

A total of 178 patients were recruited across 24 centers with 53 surgeons. The median follow-up time at the time of this analysis was 37 months (IQR: 30–38 months). Complete 3-year clinical follow-up data were available for 87% of eligible patients, with adequate radiographic follow-up to assess technical observations available for 79% of patients.

Discussion

We report the first detailed clinical prospective outcomes following EVAR using the Medtronic Endurant Stent Graft System after its FDA approval for use in the United States in which almost all performed procedures met IFU. Stent graft evolution has led to increasingly optimal designs, focusing on improving deployment precision, graft flexibility, and sheath profile, while also accommodating more challenging anatomy, including short infrarenal necks, aortic tortuosity, and calcified and/or

Conclusions

The Endurant stent graft system can achieve excellent short-term and mid-term results despite wide anatomic inclusion criteria. Reintervention is low, with only one in 16 patients undergoing reintervention by 3-year follow-up. Long-term follow-up with detailed anatomic data from large, multicenter registries could improve graft selection in the future.

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Cited by (11)

A systematic review and meta-analysis of long-term reintervention after endovascular abdominal aortic aneurysm repair
2020, Journal of Vascular Surgery
Citation Excerpt :
For each year, studies were included if they reported the number of patients at risk for that year, and studies were excluded if they did not report the number of patients at risk. Six studies did not report the number of patients at risk for any time period and were excluded from analysis.27-32 For our secondary analysis, we used linear regression to examine the association between Kaplan-Meier freedom from reintervention and median year of EVAR implantation.
Patients who undergo endovascular aneurysm repair (EVAR) often require reintervention after the index repair. The long-term rate of reintervention and how this has changed with newer device technology are poorly understood. Therefore, we performed a systematic review and meta-analysis of the available literature to determine long-term freedom from reintervention after EVAR and the change in reintervention rates over time.
We performed a systematic review of MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We included randomized controlled trials and observational studies that documented the rate of reintervention after EVAR. We performed a meta-analysis of Kaplan-Meier freedom from reintervention at each year after EVAR. We used linear regression to evaluate change in reintervention rate over time with newer device technology.
We included a total of 30 studies (randomized trials, n = 3; observational studies, n = 27) comprising 32,126 patients in this review and meta-analysis. Studies ranged in the implantation date of the EVAR device from 1996 to 2014. The probability of freedom from reintervention was 81% (95% confidence interval [CI], 77%-85%) at 5 years, 70% (95% CI, 65%-76%) at 10 years, and 64% (95% CI, 46%-79%) at 14 years. Linear regression demonstrated an improvement in freedom from reintervention when results were stratified by the year of device implantation. At 1 year, estimated freedom from reintervention improved from 90% in 1998 to 94% in 2008 (n = 26 studies; R² = 0.11; P = .10). At three years, estimated freedom from reintervention improved from 77% in 1998 to 90% in 2008 (n = 26 studies; R² = 0.27; P = .006). At 5 years, estimated freedom from reintervention improved from 68% in 1998 to 81% in 2008 (n = 22 studies; R² =0.12; P = .12). At 7 years, estimated freedom from reintervention improved from 51% in 1998 to 86% in 2011 (n = 22 studies; R² = 0.40; P = .015).
EVAR patients remain at risk for reintervention indefinitely, and therefore lifelong surveillance is imperative. Encouragingly, reintervention rates have improved over time, with newer devices exhibiting lower rates. Reintervention rate remains an important metric for new devices and registries.
Index and follow-up costs of endovascular abdominal aortic aneurysm repair from the Endurant Stent Graft System Post Approval Study (ENGAGE PAS)
2020, Journal of Vascular Surgery
Citation Excerpt :
The primary clinical end point was freedom from aneurysm-related mortality. Secondary clinical end points included technical success rates, serious adverse events, aneurysm rupture, endoleaks, and additional secondary interventions related to the aneurysm or stent graft system.14 The ENGAGE PAS protocol was approved by each study site's institutional review board and is registered on clinicaltrials.
Trials for endovascular aneurysm repair (EVAR) report lower perioperative mortality and morbidity, but also higher costs compared with open repair. However, few studies have examined the subsequent cost of follow-up evaluations and interventions. Therefore, we present the index and 5-year follow-up costs of EVAR from the Endurant Stent Graft System Post Approval Study.
From August 2011 to June 2012, 178 patients were enrolled in the Endurant Stent Graft System Post Approval Study de novo cohort and treated with the Medtronic Endurant stent graft system (Medtronic Vascular, Santa Rosa, Calif), of whom 171 (96%) consented for inclusion in the economic analysis and 177 participated in the quality-of-life (QOL) assessment over a 5-year follow-up period. Cost data for the index and follow-up hospitalizations were tabulated directly from hospital bills and categorized by Uniform Billing codes. Surgeon costs were calculated by Current Procedural Terminology codes for each intervention. Current Procedural Terminology codes were also used to calculate imaging and clinic follow-up reimbursement as surrogate to cost based on year-specific Medicare payment rates. Additionally, we compared aneurysm-related versus nonaneurysm-related subsequent hospitalization costs and report EuroQol 5D QOL dimensions.
The mean hospital cost per person for the index EVAR was $45,304 (interquartile range [IQR], $25,932-$44,784). The largest contributor to the overall cost was operating room supplies, which accounted for 50% of the total cost at a mean of $22,849 per person. One hundred patients had 233 additional post index admission inpatient admissions; however, only 32 readmissions (14%) were aneurysm related, with a median cost of $13,119 (IQR, $4570-$24,153) compared with a nonaneurysm-related median cost of $6609 (IQR, $1244-$26,466). Additionally, 32 patients were admitted a total of 37 times for additional procedures after index admission, of which 14 (38%) were aneurysm-related. The median cost of hospitalization for aneurysm-related subsequent intervention was $22,023 (IQR, $13,177-$47,752), compared with a median nonaneurysm-related subsequent intervention cost of $19,007 (IQR, $8708-$33,301). After the initial 30-day visit, outpatient follow-up imaging reimbursement averaged $550 per person per year ($475 for computed tomography scans, $75 for the abdomen), whereas annual office visits averaged $107 per person per year, for a total follow-up reimbursement of $657 per person per year. There were no significant differences in the five EuroQol 5D QOL dimensions at each follow-up compared with baseline.
Costs associated with index EVAR are driven primarily by cost of operating room supplies, including graft components. Subsequent admissions are largely not aneurysm related; however, cost of aneurysm-related hospitalizations is higher than for nonaneurysm admissions. These data will serve as a baseline for comparison with open repair and other devices.
Long-term Results of 180 Consecutive Patients with Abdominal Aortic Aneurysm Treated with the Endurant Stent Graft System
2020, Annals of Vascular Surgery
Citation Excerpt :
Together they included patient numbers between 178 and 712, with a median follow-up between 19.2 and 42 months.11,12,19 One reported survival outcomes at 3 years of follow-up,19 the other 2 reported 5-year survival rates and included patients with anatomical morphology outside IFU recommendations.11,12 All had missing data related to patients lost to follow-up or withdrawn from the study (1.2–13%).
Registry studies have shown that the Endurant stent graft is associated with low rates of all-cause and aneurysm-related mortality when used for the endovascular treatment of abdominal aortic aneurysm (AAA). However, many were limited by length of follow-up and all had a proportion of patients lost to follow-up. The aim of this study is to report results from a large, real-world experience using Endurant, utilizing methods to ensure complete ascertainment of mortality.
This study describes a large, single vascular unit experience using the Endurant stent graft in consecutive patients treated between August 2008 and March 2019.
One-hundred eighty patients (mean age 76.0 ± 8.6 years; 90% male) with mean AAA diameter of 57.5 ± 10.5 mm underwent endovascular aneurysm repair (EVAR). Technical success was achieved in all cases. At median follow-up of 55.0 months (interquartile range 29.8–79.0), 51 (28.3%) patients had died. Kaplan–Meier estimate of 5-year overall survival and freedom from aneurysm-related death was 71.6% and 99.4%, respectively. Lower survival rates were observed in patients who underwent EVAR at age ≥80 years (59.2% vs. 78.3%, P < 0.01) and with aneurysm diameter ≥70 mm (55.6% vs. 73.8%, P = 0.03). Thirteen endoleaks (7.2%; 4 type 1A, 2 type 1B, 7 type 2) were observed during follow-up (mean time from implantation 8.7 ± 4.2, range 1–52 months). Eleven patients (6.1%) required secondary intervention for limb occlusion (n = 7), endoleak (n = 3), and restenosis (n = 1). Patients treated within (n = 104; 57.8%) and outside (n = 76; 42.2%) the manufacturer’s instructions for use (IFU) had similar rates of endoleak (7 [6.7%] vs. 6 [7.9%]; P = 0.76), secondary re-intervention (7 [6.7%] vs. 4 [5.3%]; P = 0.74) and overall-survival (72 [69.2%] vs. 55 [72.3%]; P = 0.46).
Results from this real-world study of consecutive patients treated for AAA using the Endurant stent graft demonstrate that it is safe and effective, with excellent long-term outcomes for anatomy that falls both inside and outside IFU recommendations.
Endograft Specific Haemodynamics After Endovascular Aneurysm Repair: Flow Characteristics of Four Stent Graft Systems
2019, European Journal of Vascular and Endovascular Surgery
Citation Excerpt :
Despite these differences between the endografts, clinical experience with all four devices has demonstrated good results at least during the early and mid term periods. The applicability of the Endurant stent graft has been thoroughly tested in several situations and showed promising results.44 Additionally, the Excluder stent graft system with infrarenal fixation system has also yielded promising results.45
The implication of haemodynamics in the occurrence of complications after endovascular aneurysm repair (EVAR) has been raised in the literature. Different aortic stent graft configurations may lead to different haemodynamic properties. The current study deals with the post-operative haemodynamic variability between four stent graft systems with different structure, material, and type of fixation.
Computed tomography data of 32 patients were used, equally distributed among the four endograft groups, namely the AFX, Endurant, Excluder, and Nellix. Velocity, wall shear stress (WSS), and helicity statistics were calculated, in regions around the flow division where disturbances are expected. The haemodynamic data were compared between and within the groups.
The morphology of AAAs pre-operatively did not vary significantly among the four groups. Before the flow division, lowest velocity was observed in Endurant cases and highest in Nellix cases. Endurant induced the lowest peak WSS and Nellix the highest (p = .03). The helicity levels were low in AFX and Nellix cases and high in Endurant and Excluder cases. After the flow division, the trend in the results was preserved. Nellix induced the highest velocity and WSS, followed closely by Excluder and AFX. There was a significant increase of helicity before and after flow division in AFX (p <0.001, R² = 0.09) and Nellix (p <0.001) cases.
It has been shown that different types of endografts induce variable haemodynamic conditions around the flow division. The parallel limb structure, featured by Nellix, seems to induce favourable flow conditions in terms of velocity and WSS, while helical flow before the flow division is suppressed. High WSS is generally considered to be a desirable flow characteristic in endovascular devices, whereas helicity extremes (very low or high) are potentially a negative sign. Endurant, with the stiffer material and the short neck structure, was associated with the lowest blood velocity and WSS values but preserved high helicity levels. The AFX and Excluder, which include the same material, induced similar haemodynamic conditions.
Patient longevity and survival with custom-made endovascular solutions: The Fenestrated Anaconda<sup>TM</sup> approach
2023, Asian Cardiovascular and Thoracic Annals
Five-year outcomes of the Bi- versus Trimodular Endurant<sup>TM</sup> stent-graft in 100 patients with infrarenal abdominal aortic repair
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: Presented at the 45th Annual Society for Clinical Vascular Surgery Meeting, Lake Buena Vista, FL, March 19–22, 2017.

: S.E.D., K.E.S., and T.F.X.O. are supported by the Harvard-Longwood Research Training in Vascular Surgery NIH T32 grant 5T32HL007734-22.

: The authors declare no conflicts of interest to disclose.

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Clinical ResearchThree-Year Results of the Endurant Stent Graft System Post Approval Study

Background

Methods

Results

Conclusions

Introduction

Section snippets

Methods

Results

Discussion

Conclusions

J Vasc Surg

J Vasc Surg

Lancet

Eur J Vasc Endovasc Surg

J Vasc Surg

J Vasc Surg

J Vasc Surg

J Vasc Surg

J Vasc Surg

Clinical Research
Three-Year Results of the Endurant Stent Graft System Post Approval Study