Endovascular aortic aneurysm repair in patients with narrow aortas using bifurcated stent grafts is safe and effective

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.

Midterm Results of Iliac Branch Devices in a Newly Established Aortic Center

The first-line treatment of common iliac artery aneurysms is endovascular repair. International guidelines recommend the preservation of the internal iliac artery, which is best achieved by the implantation of an iliac bifurcation device (IBD). Our aim was to evaluate the initial midterm results of IBDs in the leading vascular center of Hungary. In this single-center retrospective study, relevant clinical data and the results of the imaging examinations were collected and analyzed in all patients who underwent IBD implantation between December 2010 and July 2021. Thirty-five patients (31 males, mean age: 67.9 ± 8.5 years) underwent endovascular treatment with 37 IBD implantations. Technical success was achieved in 88.2% of the patients, with no perioperative mortality or open surgical conversion. One patient was lost during follow-up. Internal iliac artery occlusion was detected in three (8.8%) patients, and reintervention was performed in five (14.7%) patients. Primary patency of the internal iliac branch was 97.1% at 1 month, 93% at 2 months, and 89.0% at 5 years. The average follow-up time was 20.1 ± 26.2 months, during which two (5.9%) deaths occurred. Our initial experience with iliac branch devices was associated with a low complication rate and a favorable outcome, which confirms the midterm success of this intervention.

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.

Unibody design for aortic disease with a narrow aortic bifurcation: tips and tricks for success

Background

Surgical management of patients with abdominal aortic diseases associated with distal narrowing is a challenging situation.

Objectives

To evaluate outcomes of unibody bifurcated endovascular stent graft repair.

Methods

This is a retrospective, observational, multi-institutional database study of a cohort of consecutive cases, approved by the local Ethics Committee. Records were reviewed of patients diagnosed from 2010 to 2020 with “shaggy” aorta, saccular aneurysm, penetrating aortic ulcer, and isolated aortic dissection located in the infrarenal abdominal aorta. All patients were treated with a unibody bifurcated stent graft. Main outcomes were technical success, procedure complications, long-term patency, and mortality in the follow-up period up to 5 years. Data on demographics, comorbidities, surgical management, and outcomes were analyzed.

Results

Twenty-three patients were treated with unibody bifurcated stent graft repair, including 7 cases of “shaggy” aorta, 3 isolated dissections of the abdominal aorta, 4 penetrating aortic ulcers, and 9 saccular aneurysms. Immediate technical success was achieved in 100% of cases. At follow-up, all stent grafts remained patent and there were no limb occlusions. The patients were symptom-free and reported no complications related to the procedure. There were 5 deaths during the follow-up period (median= 4 years), but none were related to the procedure and there were no aorta-related deaths.

Conclusions

The present study shows that unibody bifurcated stent grafting is safe and effective in this group of patients with narrow distal abdominal aorta and complex aortic pathology. The results were similar for both infrarenal aortic aneurysms and aorto-iliac atherosclerotic disease.

Results of adjunctive stenting with high-radial force stents to prevent or treat limb occlusion after EVAR

BACKGROUND

The aim of this study was to report the results of a multicenter experience on the use of adjunctive stents deployed inside abdominal aortic endografts with the purpose to prevent or treat limb occlusion after endovascular aneurysm repair (EVAR).

METHODS

Between 2010 and 2018, there were 35 patients with aorto-iliac aneurysm presenting one or more risk factors for endograft limb occlusion (narrow aortic bifurcation and/or stenotic, highly angulated or occluded iliac arteries), who were treated with standard bifurcated stent graft reinforced by the means of a single model of balloon-expandable platinum/iridium bare stent (CP Stent; NuMED, Inc., Hopkinton, NY, USA). Technical success, mortality, limb patency and reintervention rate during follow-up were the main endpoints assessed.

RESULTS

Technical success was 100%. No patients died perioperatively and no major complication was registered. During a mean follow-up of 48 months (range 1-87), neither aortic-related death nor secondary intervention was registered. At a mean follow-up imaging of 39.4 months (range 1-81) no endograft limb lost its patency.

CONCLUSIONS

The use of high-radial force balloon-expandable stents deployed inside bifurcated endografts to prevent or treat limb occlusion is a safe and effective adjunctive procedure, with outstanding long-term outcomes in terms of patency and reinterventions.

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.

An update on the improvement of patient eligibility with the use of new generation endografts for the treatment of abdominal aortic aneurysms

PURPOSE

Endovascular aneurysm repair (EVAR), performed within device instructions for use (IFU), offers improved outcomes. New endograft designs attempt to increase eligibility rates of abdominal aortic aneurysm (AAA) patients treated within device IFU. We aim to examine the anatomic suitability of the Ovation endograft in our AAA patients and compare it with the other contemporary devices.

RESEARCH DESIGN AND METHODS

Three-hundred and seven consecutive elective AAA patients treated during a 5-year period were included. Patient-specific anatomic characteristics were based on endograft IFUs to determine eligibility rates of each system.

RESULTS

Two-hundred-twenty-five patients underwent EVAR and 82 open surgery. Ineligibility for device implantation was significantly lower for the Ovation iX system (32%) compared to other devices (AFX-2:49%, Altura:49%, Anaconda:54%, Endurant II:46%, Excluder:52%, Excluder Conformable:39%, Incraft:43%, E-Tegra:52%, Zenith-Alpha:52%; P-Value<0.001). The Alto system (next-generation Ovation) achieved an even lower ineligibility rate of 30% (P = 0.008). Short proximal aortic neck length followed by access vessel inadequacy were the primary reasons for ineligibility.

CONCLUSION

The Ovation-iX included more patients with anatomic characteristics within device IFUs resulting in improved eligibility rates compared with the rest of contemporary devices. Its evolution, the Alto system, further improves patient eligibility due to the inclusion of shorter aortic necks.

EXPERT OPINION

The Ovation iX system presented a significantly better performance and was eligible for use in a greater number of patients in our series of elective AAA repairs, accommodating patient-specific aortic anatomies. Of course, performing EVAR within the endograft's IFU is important to achieve optimal and durable outcomes. The proximal neck length followed by the size of the access vessels are the two more common factors resulting in loss of eligibility. Except for overall eligibility rates, a case by case decision must be made on which is the most suitable device for each patient, based on the specific characteristics of its unique anatomy.

Five Year Patient Outcomes of Endovascular Abdominal Aortic Aneurysm Repair in the ENDURANT France Registry

OBJECTIVE

Endovascular repair is the preferred method of treatment for infrarenal abdominal aortic aneurysms with numerous publications from multiple geographic regions showing excellent patient outcomes. Since the original ACE (Anevrysme de l'aorte abdominale: Chirurgie versus Endoprothese) randomised control trial, studies of French specific population have also contributed significantly to the body of evidence in support of endovascular abdominal aortic repair.

METHODS

In the ENDURANT France registry, 180 patients were consecutively enrolled from 20 French centres starting in 2012. Investigational sites included public and private practice and differing centre volumes to be as representative of real world French experience as possible. The aim of this study was to present the five year outcomes from this registry.

RESULTS

Instructions for use (IFU) were respected in 97.8% (176/180) of patients. At five years, the Kaplan-Meier overall survival was 69.9% ± 3.5% and the freedom from aneurysm related death was 97.6% ± 1.2%. The freedom from Type IA endoleaks was 94.5% ± 1.7%, freedom from endoleaks of any type was 70.1 ± 3.4%, and freedom from secondary endovascular procedure 90.4% ± 2.6%. In addition, 61.6% (45/73) of patients exhibited sac shrinkage at five years.

CONCLUSION

In this five year report of the Endurant France registry, survival, re-intervention, and freedom from endoleak rates were comparable to recent EVAR registries and there was a high sac shrinkage rate. Secondary procedure and aneurysm rupture were lower than those of ACE, the French RCT which included older generation devices. This prospective registry demonstrates favourable five year outcomes of the Endurant stent graft used within IFU.

The Efficacy of a Protocol of Iliac Artery and Limb Treatment During EVAR in Minimising Early and Late Iliac Occlusion

OBJECTIVE

Iliac limb occlusion (ILO) is a complication of endovascular aortic repair (EVAR) and requires re-intervention in most cases. Attention to any intra-operative defect of iliac limbs and arteries may prevent ILO. The study aimed to analyse the long term effect of an intra-operative protocol of iliac limb treatment during EVAR on ILO.

METHODS

Patients treated from 2012 to 2017 for abdominal aortic aneurysm (AAA) with standard EVAR were collected prospectively. Pre-operative computed tomography angiography anatomical characteristics were evaluated. The protocol for intra-operative iliac limb management was: a. pre-EVAR angioplasty of common/external iliac artery stenosis; b. precise contralateral iliac limb deployment at the same level of the flow divider; c. iliac limb kissing ballooning with high pressure non-compliant balloons; d. iliac limb stenting for residual tortuosity/kink and adjunctive external iliac stenting for residual stenosis/dissection after EVAR. ILO was evaluated at 30 days and at follow up, which was performed by duplex ultrasonography before discharge, at three, six, and 12 months and yearly thereafter. Kaplan-Meier and Cox linear regression were used.

RESULTS

Four hundred and forty-two patients and 884 iliac limbs were included in the study. Severe iliac tortuosity and calcification were present in 15% (132/884) and 8% (70/884), respectively. External iliac angioplasty and stenting of iliac limb were performed in 2% (18/884) and 9.5% (84/884) of limbs. The thirty day mortality was 1.6%, with no ILO. At a mean follow up of 33 ± 12 months, ILO occurred in 7/884 (0.8%) limbs of six patients. Five ILO were treated by endovascular relining, two surgically: one by femorofemoral bypass and one by surgical explant. On univariable analysis, sac shrinkage was significantly associated with ILO (HR 1, 95% CI 0.8-2.5, p = .043).

CONCLUSION

A protocol of aggressive iliac limb treatment in EVAR leads to a very low rate of late ILO. The role of sac shrinkage in ILO should be investigated further.

Initial Experience and Potential Advantages of AFX2 Bifurcated Endograft System: Comparative Case Series

Purpose

Materials and Methods

Results

Conclusion

Computational Comparison Between a Classic Bifurcated Endograft and a Customized Model With "Dog Bone"-Shaped Limbs

PURPOSE

To use computational simulations to compare the hemodynamic characteristics of a classic bifurcated stent-graft to an equally long endograft design with "dog bone"-shaped limbs (DB), which have large diameter proximal and distal ends and significant narrowing at the midsection to accommodate aneurysms with an extremely narrow bifurcation.

MATERIALS AND METHODS

A 3-dimensional model was constructed using commercially available validated software. Inlet and outlet diameters were 28 and 14 mm, respectively. The total length of both models was kept constant to 180 mm, but the main body of the DB model was 20 mm shorter than the bifurcated endograft. The iliac limbs of the DB model had a 9-mm stenosis over a 30-mm segmental length in the midsection. Flow was quantified by time-averaged wall shear stress, oscillatory shear index (OSI), and relative residence time (RRT). The displacement forces in newtons (N) and maximum wall shear stress (WSS) in pascals (Pa) were compared during a cardiac cycle at 3 segments (main body, bifurcation, and iliac limbs) of both models with computational fluid dynamics analysis.

RESULTS

The DB accommodation was associated with higher forces at the main body (range 3.15-4.9 Ν) compared with the classic configuration (1.56-2.34 N). On the contrary, the forces at the bifurcation (3.81-5.98 vs 3.76-5.54 N) and at the iliac limbs (0.34-0.85 vs 0.49-0.74 N) were comparable for both models. Accordingly, maximum WSS was detected at the iliac sites for both models throughout the cardiac cycle. The highest values were detected at peak systole and equaled 26.6 and 12 Pa for the DB and bifurcated configurations, respectively. The narrow segments in the DB model displayed high stress values but low OSI and very low RRT.

CONCLUSION

The DB accommodation seems to correlate with higher displacement forces at the main body and higher stresses at the iliac limbs. Consequently, regular imaging follow-up of the DB design deems necessary to delineate its mid- and long-term clinical performance.