Technical Success and Long-Term Results with Excluder/C3 Endoprosthesis in Narrow Aortic Bifurcations: First Italian Multicentre Experience

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.

A Scoping Review on the Incidence, Risk Factors, and Outcomes of Proximal Neck Dilatation after Standard and Complex Endovascular Repair for Abdominal Aortic Aneurysms

Background: To define proximal neck dilation (PND) after standard endovascular aneurysm repair (EVAR) and fenestrated EVAR (FEVAR), determining: incidence and risk factors; evidence base that links PND to outcomes of patients; recurring themes or gaps in the literature. Methods: We performed a scoping review and included only full-text English articles with follow-up focusing on PND in patients undergoing EVAR or FEVAR, published between 2000 and 2022. The following PICO question was used to build the search equation: in patients with abdominal-aortic-aneurysm (AAA) (Population) undergoing endovascular repair (Intervention), what are the incidence, risk factors and prognosis of radiologically defined PND (Comparison) on short-term and long-term outcomes (Outcomes)? Results: 15 articles were included after review. Measurement protocols for proximal aortic neck (PAN) varied among individual studies and the definition of PND resulted as heterogeneous. Rate of patients with a PND ranged between 0% and 41%. Large proximal neck (>28 mm) and excessive graft sizing (30%) were predictors for PND. New endografts with low outward radial forces and FEVAR seemed to be protective. Surgical conversion was the definitive option in the case of patients unfit for other endovascular treatments. Conclusions: PND is a frequent finding after EVAR and FEVAR. Excessive graft oversizing and large baseline PAN were predictors of neck enlargement, independently by the type of standard endograft used. FEVAR may be considered protective against complications, together with endografts using low outward radial forces. Lifelong radiological follow-up is mandatory.

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.

Five-year outcomes of the Bi- versus Trimodular EndurantTM stent-graft in 100 patients with infrarenal abdominal aortic repair

BACKGROUND

Recent studies on the Endurant™ endografts mainly compared outcomes of the bimodular stent-graft to other manufacturer's endografts or reported results for cases outside manufacturer's instructions for use (IFU), while data on the experience of standard endovascular aortic repair (EVAR) of infrarenal abdominal aortic aneurysms (AAA) inside manufacturer's IFU comparing the bi- with the trimodular device is limited.

METHODS

Inclusion criteria were: 1) infrarenal aneurysms (>50 mm diameter) treated by Endurant^TM II (END II) or Endurant^TM IIs (END IIs) stent-graft inside manufacturer's IFU; 2) available CTA with 1 mm reconstruction of the entire aorta prior to intervention. Endpoints comparing the devices included technical success, 30-day mortality, rate of complications (bleeding with conversion to open repair, stent-graft stenosis/occlusion, acute distal embolism, infection or postprocedural necessity of dialysis), endoleaks and reinterventions (5-year follow-up). Aneurysm sac diameters were compared between baseline preinterventional CTA and last post-interventional CTA.

RESULTS

One hundred patients (90% male, mean age 74 years) treated with END II (N.=66) or END IIs (N.=34) were included. Technical success was 99%. One procedure-related active bleeding occurred ending up in surgical conversion (END II N.=1). 30d mortality was 0%. No initial type I/III endoleaks were present. Re-interventions were required in 19/100 (19%) of patients (END II N.=10; END IIs N.=9, P=0.17). The outcome of EVAR including technical success, 30d mortality, rate of complications, endoleaks and re-interventions showed no significant differences comparing END II/IIs.

CONCLUSIONS

Five-year outcomes of EVAR show consistently safe and effective results for either END II or IIs device.

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.

Impact of Cone Beam Computed Tomography in Advanced Endovascular Aortic Aneurysm Repair Using Last Generation 3D C-arm

BACKGROUND

To report the early outcomes of cone beam computed tomography (CBCT) using last generation 3D C-arm in patients undergone advanced endovascular aortic aneurysm repair (AdEVAR) and to identify risk factors that may predict any un-planned procedures.

METHODS

Patients undergone AdEVAR between December 2017 and December 2018 were enrolled. Final CBCT was performed in all patients after digital subtraction angiography. Primary end points were the incidence of any positive findings and the following unplanned procedures intended as any endovascular manoeuvre performed to fix such technical defect. The secondary endpoints were comparison of outcomes between patients with positive findings undergone unplanned procedure (Group A) versus patients without findings (Group B).

RESULTS

132 patients underwent endovascular treatment for aortic aneurysm. Of these, 22 (33%) fenestrated-branched endovascular aneurysm repairs (F-BEVAR), 21 (29%) EVAR with iliac branch devices, 19 (26%) abdominal and 10 (14%) thoracic EVAR were included in the study. Unplanned procedures after CBCT were necessary in 22 patients (31%). Patients in both groups were similar excepted for BMI >25 kg/m² (55% vs. 26%), hostile iliac anatomy (64% vs. 32%) and previous aortic treatment (73% vs. 32%) (P < 0.05). The odds ratios for unplanned procedure in case of previous aortic treatment was 6.76 (95% CI, 1.97-23.16; P = 0.002).

CONCLUSION

The use of CBCT, especially in challenging scenarios, can reveal technical defects and may potentially limit the need for late reintervention. Patients undergone previous aortic surgery should be carefully evaluated and routine CBCT should be performed.

Combined Pull through and Balloon Anchoring Bailout Technique to Repair a Failed Bifurcated Endovascular Aortic Repair

BACKGROUND

To describe a bailout technique used to manage the left stump of a bifurcated endograft that was stuck above a narrowed distal aortic neck.

METHODS

An 80-year-old man with a suprarenal aneurysm was treated with a custom-made 4-vessel fenestration endograft. During the procedure, the left stump of the distal bifurcated graft module was chased out of a narrow distal aortic neck and became stuck horizontally at the bottom of the aortic aneurysmal sac. Through a femoral to left subclavian artery through-and-through percutaneous access, a balloon-anchoring technique was successfully used to return the endograft stump into the narrowed aortic neck and exclude the aneurysm.

CONCLUSIONS

The combined technique of a through-and-through and anchoring balloon was found to be suitable for introducing an endograft limb into a narrow distal aortic neck.

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.