Outcomes of Endurant stent graft in narrow aortic bifurcation

The Role of Narrow Aortic Bifurcation in Affecting EVAR Treatment and Outcomes

BACKGROUND

The narrow aortic bifurcation (NAB) is considered a risk factor for endograft thrombosis after aorto-biiliac endovascular aneurysm repair (EVAR) for aortic or iliac aneurysm. Nowadays, no consensus on the threshold diameter for the definition of NAB is reached and other aortic bifurcation features are rarely considered. The aim of the study is to assess the EVAR outcomes using bifurcated endograft according to anatomical characteristics of aortic bifurcation.

METHODS

The study included patients treated with primary EVAR from 2016 to 2022. A retrospective analysis of single-center prospectively collected database was performed. Patients were classified in standard aortic bifurcation (SAB) (aortic bifurcation diameter >20 mm), NAB (≤20 mm and >16 mm), and extremely NAB (eNAB) (≤16 mm). The 3 groups were compared in terms of patient demographics, risk factors, procedure setting (elective or urgent/emergent), and type of deployed endograft. In NAB and eNAB groups, severe calcification (SC) and length of stenotic aortic bifurcation >10 mm (long-NAB) were assessed from preoperative imaging. In SAB, NAB, and eNAB groups, following outcomes were evaluated: rate of intraoperative iliac endograft stenting (unilateral or kissing stenting), primary patency (PP), freedom from endograft-related reintervention, and overall survival during follow-up.

RESULTS

The total number of deployed aorto-biiliac endografts was 365 (mean age: 76.6 ± 7.4 years; male 89.3%): SAB 298 (81.6%), NAB 57 (15.6%), and eNAB 10 (2.7%) cases. Female gender, chronic obstructive pulmonary disease patients, and active smokers were more frequent in patients with smaller aortic bifurcation diameter (P = 0.002, 0.039, and 0.010, respectively). In NAB and eNAB groups, SC was reported in 18/67 cases (26.9%) and long-NAB in 15/67 cases (25.4%). Patients with eNAB have more frequent SC of aortic bifurcation (60% vs. NAB 21.1%, P = 0.018) and long-NAB (50% vs. NAB 17.5%, P = 0.023). In SAB, NAB, and eNAB, intraoperative iliac endograft stenting was performed in 34/298 (11.4%), 9/57 (15.8%), and 5/10 (50%), respectively (P = 0.001). Kissing stenting was performed more frequently in groups with smaller aortic bifurcation diameter (P = 0.010). Mean follow-up was 30.2 ± 21.5 months. At 1, 3, and 5 years, PP was 98.5%, 96.6%, and 95.6%, respectively. eNAB had lower rate of PP compared to NAB group (P = 0.030). Long-NAB had lower rate of PP (P = 0.035). At 1, 3, and 5 years, endograft-related reintervention was 96.8%, 86.7%, and 76.7%, respectively, with no differences between 3 groups (P = 0.423). At 1, 3, and 5 years, survival was 92.5%, 77.6%, and 58.1%, respectively, with no difference between SAB, NAB, and eNAB (P = 0.673).

CONCLUSIONS

Female gender, chronic obstructive pulmonary disease patients, and active smokers have more frequently smaller aortic bifurcation diameter. eNAB patients have more challenging anatomical characteristics compared with NAB group, requiring higher rate of intraoperative stenting, especially kissing stenting. Mid-term PP seems to be negatively influenced by aortic bifurcation ≤16 mm and long-NAB.

Side-by-side deployment of gore excluder legs at a narrow terminal aorta for endovascular aneurysm repair

PURPOSE

A narrow terminal aorta is a risk factor for endograft occlusion after endovascular aneurysm repair. To minimize limb complications, we used Gore Excluder legs positioned side-by-side at the terminal aorta. We investigated the outcomes of our strategy for endovascular aneurysm repair in patients with a narrow terminal aorta.

METHODS

We enrolled 61 patients who underwent endovascular aneurysm repair with a narrow terminal aorta (defined as < 18 mm in diameter) from April 2013 to October 2021. The standard procedure involves complete treatment with the Gore Excluder device. When other types of main body endografts were used, they were deployed proximal to the terminal aorta, and we used the Gore Excluder leg device in the bilateral limbs. Postoperatively, the intraluminal diameter of the legs at the terminal aorta was measured to assess the configuration.

RESULTS

During the follow-up period (mean: 2.7 ± 2.0 years), there were no aorta-related deaths, endograft occlusions, or leg-related re-interventions. There were no significant differences between the pre- and postoperative ankle-brachial pressure index values in the dominant and non-dominant legs (p = 0.44 and p = 0.17, respectively). Postoperatively, the mean difference rate (defined as [dominant leg diameter-non-dominant leg diameter]/terminal aorta diameter) was 7.5 ± 7.1%. The difference rate was not significantly correlated with the terminal aortic diameter, calcification thickness, or circumferential calcification (r = 0.16, p = 0.22; r = 0.07, p = 0.59; and r = - 0.07, p = 0.61, respectively).

CONCLUSIONS

Side-by-side deployment of Gore Excluder legs produces acceptable outcomes for endovascular aneurysm repair with a narrow terminal aorta. The endograft expansion at the terminal aorta is tolerable without influencing calcification distribution.

The influence of narrow aortic bifurcation on limb graft patency: a two-center retrospective study

BACKGROUND

Narrow aortic bifurcation (NAB) has been considered as a potential risk factor for graft limb thrombosis after endovascular aortic repair (EVAR). The aim of this study was to compare mid- and long-term outcome of EVAR in patients with NAB and standard aortic bifurcation (SAB).

METHODS

Data from patients receiving EVAR were prospectively collected and retrospectively analyzed. In case of angiographic limb stenosis (>50%), additional stenting was performed. Patients with a NAB (≤20mm) were included in the NAB group, the remaining patients in the SAB group. Primary endpoints were limb thrombosis rate and technical success.

RESULTS

A total of 902 patients were included; 18.3% (N.=165/902) in the NAB and 81.7% (N.=737/902) in the SAB group. Mean follow-up time was 43 months (range 0-198 months). Bilateral stenting of the aortic bifurcation was performed in 2.7% (N.=27/902), 8.5% (N.=14/165) in the NAB and 1.4% (N.=10/737) in the SAB group (P=0.001). Limb thrombosis was found in 2.8% (N.=25/902), 3.6% (N.=6/165) in the NAB and 2.6% (N.=19/737) in the SAB group (P=0.55). Technical success was 97.8%, 98.8% in the NAB and 97.6% in the SAB group (P=0.33). Device related reintervention rate was 16% (N.=144/902), 15.2% in the NAB and 16.1% in the SAB group (P=0.75).

CONCLUSIONS

Standard EVAR could safely be performed in patients with NAB (≤20mm) when a low threshold for additional stenting was applied. This resulted in no significant higher incidence of limb thrombosis. Additional stent deployment did not increase the complication rate.

Endovascular Aneurysm Repair With AFX Stent-Grafts or Tube Grafts for Sacciform Infrarenal Pathologies in a Narrow Aortic Anatomy

PURPOSE

The objective of this study was to compare the outcomes of patients treated with tube grafts and AFX stent-graft in the narrow infrarenal aortic anatomy.

MATERIALS AND METHODS

Patients with penetrating aortic ulcers (PAUs) or sacciform aneurysms of the infrarenal aorta and an aortic bifurcation diameter ≤20 mm who underwent endovascular aneurysm repair (EVAR) with bifurcated AFX or tube stent-grafts (TUBE) between 2012 and 2020 were included. Demographic data and the outcome of the AFX group were compared with the TUBE group. All morphological measurements in the preoperative and postoperative computed tomography scans were performed in the aortic centerline.

RESULTS

Fifty-one patients (female: 12/51; 29%; median age: 72 years [63, 77]) with a median follow-up of 10 (3, 39) months, were included, of whom 35/51 (69%) had PAUs and 11/51 were symptomatic (22%). The aortic bifurcation diameter was 17 mm (15, 18) with severe calcifications in 25/51 (49%). The distal aortic landing zone was longer in the TUBE group (9 mm vs 24 mm; p<0.001). The technical success was 96% with a median aneurysm shrinkage of 8% (3, 13), which was comparable between the groups (p=0.264). Periprocedural mortality, conversion to open surgery, myocardial infarction, and stroke were not observed. Two type Ia endoleaks (EL) and 2 type Ib EL occurred, all in the TUBE group (Type 1 EL; 19 vs 0%; p=0.013). The limb patency in the AFX group was 100%. One patient with a tube graft developed an infrarenal aortic thrombosis 40 months after the intervention. The reintervention rate in the TUBE group was higher (14 vs 0%; p=0.032) and included 3 aortic cuff implantations and 1 covered endovascular aortic reconstruction of aortic bifurcation (CERAB).

CONCLUSION

AFX stent-graft showed a lower rate of type I endoleaks and reinterventions in sacciform infrarenal aortic pathologies during the early and midterm follow-up.

Use of the AFX Stent Graft in Patients with Extremely Narrow Aortic Bifurcation: A Multicenter Retrospective Study

Introduction

This study analyzed the patient outcomes following endovascular aortic aneurysm repair (EVAR) for infrarenal aortic pathologies with very narrow aortic bifurcations using the AFX stent graft.

Methods

The data was retrieved from the archived medical records of 35 patients treated for abdominal aortic aneurysm (AAA) (48.6%) or penetrating aortic ulcer (PAU) (51.4%) with very narrow aortic bifurcation between January 2013 and May 2020. Patient survival, freedom from endoleak (EL), and limb occlusion were estimated applying the Kaplan–Meier method.

Results

The mean follow-up time was 20.4 ± 22.8 months. The mean aortic bifurcation diameter was 15.8 ± 2.2 mm. Technical success was 100%, and no procedure-related deaths occurred. Two type II ELs occurred within 30-day follow-up. We observed one common iliac artery stenosis at four months and one type III EL at 54 months in the same patient, both of which required re-intervention. Overall patient survival was 95 ± 5% (AAA: 100%; PAU: 89 ± 10%), freedom from limb occlusion was 94 ± 5% (AAA: 91 ± 9%; PAU: 100%), freedom from type II EL was 94 ± 4% (AAA: 88 ± 8%; PAU: 100%), and freedom from EL type III was 83 ± 15% (AAA: 80 ± 18%; PAU: 100%) at the end of the follow-up period.

Conclusions

Very narrow aortic bifurcations may predispose patients to procedure-related complications following EVAR. Our results suggest a safe use of the AFX stent graft in such scenarios. The overall short- and long-term procedure-related patient outcomes are satisfying albeit they may seem superior for PAU when compared to AAA.

Endovascular Aneurysm Repair with Bifurcated Stent Grafts in Patients with Narrow Versus Regular Aortic Bifurcation: Systematic Review and Meta-analysis of Comparative Studies

BACKGROUND

Narrow aortic bifurcation (NAB) is considered as a risk factor for endograft limb thrombosis. The purpose of the study was to investigate the effect of narrow aortic bifurcation on outcomes of elective endovascular aneurysm repair (EVAR).

METHODS

A systematic review that conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. We searched electronic bibliographic databases using a combination of controlled vocabulary (thesaurus) and free-text terms to identify relevant studies comparing outcomes of EVAR in patients with NAB versus those with regular aortic bifurcation. Pooled estimates of dichotomous outcomes were calculated using odds ratio (OR) and those of continuous outcomes using mean difference and 95% confidence interval (CI). To account for expected heterogeneity, the random-effects model was applied for statistical analysis.

RESULTS

Six observational studies were included, reporting a total of 2,673 patients (412 with NAR and 2,261 with friendly anatomy). Perioperative mortality was similar between the groups (OR 1.14, 95% CI 0.30-4.34, P = 0.85, I² = 0%). Limb stenosis and kinking requiring additional intraoperative procedures was significantly more common among patients with NAB (OR 3.02, 95% CI 2.16-4.22, P < 0.00001, I² = 0%). Nevertheless, 30-day reintervention rate was similar between the groups, as was the rate of limb occlusion during follow-up.

CONCLUSIONS

Available evidence suggests that at the expense of significantly more intraoperative additional procedures, EVAR with bifurcated devices can be safely performed in patients with NAB.

Effect of the Terminal Aortic Diameter on the Patency Rate of Iliac Limbs after Endovascular Aortic Repair

Objective: Endograft limb occlusion (ELO) is a complication of endovascular aneurysm repair (EVAR). In this study, we investigated the mechanism and anatomical features of ELO.

Materials and Methods: We retrospectively reviewed 227 consecutive patients with abdominal aortic aneurysm who underwent EVAR between 2007 and 2017. We then analyzed the preoperative risk factors and anatomical features of patients with ELO.

Results: A total of nine patients had ELO (4.0%). The diameter of the terminal aorta was significantly smaller in patients with ELO than in patients without ELO (18.0 mm vs. 22.3 mm, p=0.039). We measured the diameter of each limb near the terminal aorta. The smaller limb (SL) was occluded in all patients with occlusion. The difference between the larger limb (LL) and the SL (LL-SL) was significantly larger in patients with ELO than in patients without ELO (4.0 mm vs. 1.7 mm, p<0.001). The following were considered risk factors for ELO: younger age, narrow terminal aorta, severe calcification at the terminal aorta, and use of an Endurant device.

Conclusion: ELO occurs when the diameter of one side of the stent graft limb is small compared with the diameter of the other side owing to the narrow terminal aorta and calcification.

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.