Long-term Results of 180 Consecutive Patients with Abdominal Aortic Aneurysm Treated with the Endurant Stent Graft System

Long-Term Outcomes of Endovascular Repair Within and Outside the Instructions for Use in Korean Patients With Abdominal Aortic Aneurysm

OBJECTIVE

Endovascular aneurysm repair (EVAR) has been used worldwide to treat abdominal aortic aneurysms (AAAs). Outcomes after EVAR within and outside the instruction for use (IFU) remain controversial. We analyzed long-term outcomes of EVAR within-the-IFU compared with that outside-the-IFU and baseline clinical/anatomical characteristics that influence outcomes of EVAR.

METHODS

The study included 546 patients who underwent EVAR for infrarenal AAA from 1997 to 2021 at 2 Korean medical centers. The primary endpoint was graft-related adverse events (GRAEs), including type 1 or 3 endoleak, reintervention (included open conversion), aneurysm sac enlargement, aneurysm-related mortality (ARM), rupture, stent-graft migration, and stent thrombotic occlusion.

RESULTS

The patients who underwent EVAR outside the IFU were 287 (52.6%). A neck angle of >60° was most common outside the IFU criteria (n=146, 50.9%). This study revealed that patients outside the IFU had a higher rate of GRAEs compared with patients within the IFU (hazard ratio [HR]: 1.879; 95% confidence interval [CI]: 1.045-2.386). A neck angle of >60° was a significant risk factor for GRAEs (adjusted HR: 2.229; 95% CI: 1.418-3.503), type 1 or 3 endoleak (adjusted HR: 2.640; 95% CI: 1.343-5.189), and reintervention (adjusted HR: 1.891; 95% CI: 1.055-3.388).

CONCLUSIONS

Our study revealed EVAR with outside the IFU was associated with increased GRAEs, mainly attributed to endoleak and ARM, compared with EVAR with within the IFU. In addition, severe neck angulation was an independent risk factor for GRAEs, type 1 or 3 endoleak, and reintervention.

CLINICAL IMPACT

Our study revealed endovascular aneurysm repair (EVAR) with outside-the-instruction for use (IFU) was associated with increased graft-related adverse events (GRAEs) compared with EVAR with within-the-IFU. In the low-risk population, the incidence of GRAEs and Aneurysm related mortality were higher in the outside-the-IFU group rather than within-the-IFU group. In addition, severe neck angulation was an independent risk factor for GRAEs, type 1 or 3 endoleak and reintervention.

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.

Conical Aortic Neck as a Predictor of Outcome after Endovascular Aneurysm Exclusion: Midterm Results

BACKGROUND

Conical neck may affect endovascular aneurysm repair (EVAR) outcomes. The aim of this study was to present EVAR neck adverse events [endoleak type Ia (ET Ia) and graft migration], in patients with conical neck morphology compared to patients with non-conical necks. An additional analysis of the factors that may affect neck adverse events in patients with conical necks, during the first postoperative year, was executed.

METHODS

A retrospective analysis of prospective data was conducted, including patients that underwent elective EVAR, between 2017 and 2019. All patients completed the clinical and imaging follow-up of the initial 12 months. Regarding imaging, all cases underwent computed tomography angiography (CTA), preoperatively, at the 1st and 12th month of follow-up. Preoperative and postoperative aneurysm anatomic characteristics (supra-renal and infra-renal aortic diameters, aneurysm diameter, neck angle, thrombus, and calcification) were recorded. Proximal neck was defined as the infrarenal aortic segment, with a diameter less than 30 mm. Conical neck was any neck with a diameter increase ≥2 mm per cm of length (from outer-to-outer aortic wall). The proximal 15 mm of the neck length were considered the zone of endograft sealing. Migration was any ≥10 mm caudal movement of the endograft, relative to its position detected at the CTA of the first month. Neck adverse events were defined as the composite event of ET Ia and migration.

RESULTS

The cohort included 150 patients; 66 (44%) presented conical neck morphology. No significant difference was detected regarding the preoperative anatomic characteristics between the conical and non-conical groups. Only distal (15 mm) neck diameter was wider in the conical group (P < 0.001). Supra-renal active fixation was used in 63.3% of the total cohort; 59.5% in patients with non-conical necks and 68.2% in patients with conical morphology (P = 0.275). Graft oversizing was 18.2% and 18.7% in the non-conical and conical group, respectively (P = 0.248). Oversizing >20% was equal between groups [37.8% vs. 33.3%% (P = 0.608) while oversizing ≥30% was more common among patients with conical necks (3.5% vs. 10.6%, P < 0.001, 3.2 odds ratio, 95% confidence interval: 0.79, 12.91). Regarding ET Ia and migration, no difference was recorded between the groups. In a subanalysis among patients with conical necks, a lower graft migration rate was detected among patients with higher oversizing rate (P = 0.037).

CONCLUSIONS

EVAR may offer similarly good midterm outcomes in patients with conical and non-conical neck anatomy. An oversizing to the higher suggested rate may be preventive of graft migration during the first postoperative year in necks with conical morphology. Aggressive oversizing (>20%) do not offer any benefit regarding the prevention of adverse events among patients with conical necks.

Predictors and Consequences of Sac Shrinkage after Endovascular Infrarenal Aortic Aneurysm Repair

Background: Aneurysm shrinkage has been proposed as a marker of successful endovascular aneurysm repair (EVAR). We evaluated the impact of sac shrinkage on secondary interventions, on survival and its association with endoleaks, and on compliance with instructions for use (IFU). Methods: This observational retrospective study was conducted on all consecutive patients receiving EVAR for an infrarenal abdominal aortic aneurysm (AAA) using exclusively Endurant II/IIs endograft from 2014 to 2018. Sixty patients were entered in the study. Aneurysm sac shrinkage was defined as decrease ≥5 mm of the maximum aortic diameter. Univariate methods and Kaplan–Meier plots assessed the potential impact of shrinkage. Results: Twenty-six patients (43.3%) experienced shrinkage at one year, and thirty-four (56.7%) had no shrinkage. Shrinkage was not significantly associated with any demographics or morbidity, except hypertension (p = 0.01). No aneurysm characteristics were associated with shrinkage. Non-compliance with instructions for use (IFU) in 13 patients (21.6%) was not associated with shrinkage. Three years after EVAR, freedom from secondary intervention was 85 ± 2% for the entire series, 92.3 ± 5.0% for the shrinkage group and 83.3 ± 9% for the no-shrinkage group (Logrank: p = 0.49). Survival at 3 years was not significantly different between the two groups (85.9 ± 7.0% vs. 79.0 ± 9.0%, Logrank; p = 0.59). Strict compliance with IFU was associated with less reinterventions at 3 years (92.1 ± 5.9% vs. 73.8 ± 15%, Logrank: p = 0.03). Similarly, survival at 3 years did not significantly differ between strict compliance with IFU and non-compliance (81.8 ± 7.0% vs. 78.6 ± 13.0%, Logrank; p = 0.32). Conclusion: This study suggests that shrinkage ≥5 mm at 1-year is not significantly associated with a better survival rate or a lower risk of secondary intervention than no-shrinkage. In this series, the risk of secondary intervention regardless of shrinkage seems to be linked more to non-compliance with IFU. Considering the small number of patients, these results must be confirmed by extensive prospective studies.

Up to 10-year follow-up after EVAR with the Endurant stent graft system: a single-center experience

BACKGROUND

Endovascular aneurysm repair (EVAR) has become the preferred treatment for infrarenal abdominal aortic aneurysms (AAA) over open surgical repair. The Endurant stent graft is widely used, and large registries report low rates of aneurysm-related mortality and reinterventions at midterm follow-up. Reports of long-term follow-up are limited. The aim of this study is to report our experiences and share our results, reintervention rate and mortality at long-term follow-up after using the Endurant stent graft.

METHODS

All consecutive patients treated between 2009 and 2013 with the Medtronic Endurant I and II stent graft for an infrarenal AAA in an elective setting were included. Primary outcomes were overall and aneurysm-related survival and reintervention rates.

RESULTS

One hundred sixty-five consecutive patients (median age 74; IQR: 68-79) with an aneurysm diameter of 62 mm (IQR: 58-70) and neck length of 29 mm (IQR: 21-40) were electively treated with the Endurant I or II stent graft. One hundred thirty-four patients (81.2%) were treated inside IFU (instructions for use) and 31 (18.8%) outside IFU. At median follow-up of 76 months (IQR: 50-97), 60 patients (36.4%) were deceased. Kaplan-Meier estimates at 10 years follow-up of overall survival and freedom from aneurysm-related mortality were respectively 48.5% (CI: 43.7-53.3%) and 97.3% (CI: 95.7-98.9%). Freedom from reintervention was 86.0% with an CI: 83.1-88.9% at 5 years follow-up and 75.6% with a CI: 70.2-81.0% at 10 years follow-up. A total of 25 (15.2%) patients had an EVAR-related reintervention; indications were endoleak (EL) type 1A (N.=11), EL type 1B (N.=3), EL type 2 (N.=6), EL type 3 (N.=1) and limb occlusion (N.=4). We found no significant differences in outcome between the inside and outside IFU groups. At 5 years follow-up 92.6% of patients had stable or decreased diameter, and 7.4% had an increased diameter.

CONCLUSIONS

This large cohort single-center study demonstrates the effectiveness and safety of the Endurant stent graft system at long-term follow-up with low reintervention rates and aneurysm-related mortality.