Analysis of predisposing factors for type III endoleaks from directional branches after branched endovascular repair for thoracoabdominal aortic aneurysms

Systematic Review and Meta-analysis of Outcomes of the Advanta V12 or iCAST Bridging Stent Graft Used for Fenestrated and Branched Endovascular Aortic Repair

OBJECTIVE

Half of re-interventions after fenestrated and branched endovascular aortic repair (FB-EVAR) are target vessel related. Regarding bridging stent choice, existing data are controversial. This meta-analysis aimed to evaluate the performance of Advanta V12/iCAST as the bridging stent in FB-EVAR.

DATA SOURCES

The English medical literature was searched through MEDLINE, Embase (via Ovid), and Cochrane databases (end date 15 April 2024).

REVIEW METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and PICO (Patient, Intervention, Comparison, Outcome) model were followed. A predefined protocol was registered to PROSPERO (CRD42024556603). Randomised controlled trials and observational studies (2010 - 2024) reporting on Advanta V12/iCAST related target vessel outcomes were eligible. Risk of bias was assessed using ROBINS-I, and evidence quality was assessed via Grading of Recommendations Assessment, Development and Evaluations (GRADE). Primary outcomes were freedom from instability, stenosis and or occlusion, types Ic and IIIc endoleak, and re-intervention of target vessels bridged with the Advanta V12/iCAST. Prevalence and regression meta-analysis were performed.

RESULTS

From 1 439 articles, ten retrospective studies (7 525 target vessels; 3 890 target vessels bridged with Advanta V12/iCAST) were included. According to ROBINS-I, no study was of high quality. Mean follow up was 24.3 (95% confidence interval [CI] 23.9 - 24.7) months. Freedom from instability, stenosis and or occlusion, and types Ic and IIIc endoleak were 94% (95% CI 91 - 96%; p < .010; I2 = 91%; GRADE certainty, very low), 97% (95% CI 96 - 98%; p =  .070, I2 = 44%; GRADE certainty, low), and 97% (95% CI 94 - 98%; p < .010; I2 = 81%; GRADE certainty, very low), respectively. Freedom from target vessel re-intervention was 95% (95% CI 92 - 97%; p < .010; I2 = 85%; GRADE certainty, very low). Four studies provided extractable data on Advanta V12/iCAST in fenestrations and four in branches. No difference was detected in freedom from instability (p = .47), stenosis and or occlusion (p = .36), and types Ic and IIIc endoleak (p = .90). Freedom from re-intervention was 93% (95% CI 87 - 96%; p < .010; I2 = 90%) in fenestrations and 95% (95% CI 91 - 97%; p = .060, I2 = 64%) in branches.

CONCLUSION

The Advanta V12/iCAST bridging stent showed high freedom from target vessel instability, stenosis and or occlusion, and endoleak. Freedom from re-intervention was 95%, being similarly high in fenestrations and branches.

Midterm Outcomes of the BeGraft and BeGraft Plus Bridging Covered Stents for Fenestrated and Branched Endovascular Aneurysm Repair

OBJECTIVE

The aim of this study was to report outcomes of the BeGraft and BeGraft Plus as bridging covered stents in fenestrated and branched endovascular aneurysm repair (FB-EVAR).

METHODS

Patients treated and followed in two institutions receiving at least one BeGraft or BeGraft Plus as bridging covered stent between January 2018 and July 2023 were included.

RESULTS

A total of 765 target vessels (TVs) in 281 patients were aimed to be bridged with the BeGraft or BeGraft Plus. Target vessel technical success was 99.5% (761/765). Estimated TV patency at one and two years was 98.5 ± 0.5% and 96.7 ± 0.9%, respectively, with no difference between fenestrations and branches. Estimated freedom from TV related endoleak at one and two years was 98.5 ± 0.5% and 97.9 ± 0.6%, respectively. Estimated freedom from endoleak at two years was lower for TVs targeted with branches compared with TVs targeted with fenestrations (94.2 ± 1.9% vs. 99.7 ± 0.3%, respectively; p < .001). Estimated freedom from TV related re-intervention at one and two years was 97.7 ± 0.6% and 97.1 ± 0.7%, respectively. Estimated freedom from TV related re-intervention at two years was lower for TVs targeted with branches compared with TVs targeted with fenestrations (93.1 ± 2.0% vs. 99.0 ± 0.5%, respectively; p < .001). Estimated freedom from TV instability at one and two years was 96.8 ± 0.7% and 94.5 ± 1.1%, respectively. Estimated freedom from TV instability at two years was 96.0 ± 1.3% for fenestrations and 91.2 ± 2.2% for branches (p = .003).

CONCLUSION

The BeGraft and BeGraft Plus covered stents showed good midterm outcomes as bridging covered stents in FΒ-EVAR. Branches showed higher instability rates compared with fenestrations. Branches showed similar patency rates to fenestrations.

Initial Outcomes of Physician-Modified Inner Branched Endovascular Repair in High-Surgical-Risk Patients

PURPOSE

To report the initial outcomes of physician-modified inner branched endovascular repair (PMiBEVAR) for pararenal aneurysms (PRAs), thoracoabdominal aortic aneurysms (TAAAs), and aortic arch aneurysms in high-surgical-risk patients.

MATERIALS AND METHODS

A total of 10 patients (6 men; median age, 83.0 years) treated using PMiBEVAR were enrolled in this retrospective, single-center study. All patients were at high surgical risk because of severe comorbidities (American Society of Anesthesiologists physical status score≥3 or emergency repair). End points were defined as technical success per patient and per vessel (successful deployment), clinical success (no endoleaks postoperatively), in-hospital death, and major adverse events.

RESULTS

There were 3 PRAs, 4 TAAAs, and 3 aortic arch aneurysms with 12 renal-mesenteric arteries and 3 left subclavian arteries incorporated by inner branches. The technical success rate was 90.0% (9/10) per patient and 93.3% (14/15) per vessel. The clinical success rate was 90% (9/10). There were 2 in-hospital deaths, unrelated to aneurysms. Paraplegia and shower emboli occurred separately in 2 patients. Three patients experienced prolonged ventilation for 3 days after surgery. Aneurysm sac shrinkage occurred in 4 patients, and aneurysm size stabilized in 1 patient during follow-up, more than 6 months later. None of the patients required intervention.

CONCLUSION

PMiBEVAR is a feasible approach for treating complex aneurysms in high-surgical-risk patients. This technology may complement the existing technology in terms of improved anatomical adaptability, no time delay and practicability in many countries. However, long-term durability remains undetermined. Further large-scale and long-term studies are needed.

CLINICAL IMPACT

This is the first clinical study to investigate outcomes of physician-modified inner branched endovascular repair (PMiBEVAR). PMiBEVAR for treating pararenal aneurysm, thoracoabdominal aortic aneurysm, or aortic arch aneurysm is a feasible procedure. This technology is likely to complement existing technology in terms of improved anatomical adaptability (compared to off-the-shelf devices), no time delay (compared to custom-made devices), and the potential to be performed in many countries. On the other hand, surgery time varied greatly depending on the case, suggesting a learning curve and the need for technological innovation to perform more consistent surgeries.

Outcome of Single Versus Dual Antiplatelet Therapy After Complex Endovascular Aortic Repair

INTRODUCTION

Despite the widespread use of branched (bEVAR) and fenestrated endovascular aortic repair (fEVAR) for complex aortic pathologies, there are no reliable recommendations regarding postsurgery antiplatelet therapy. We therefore evaluated the outcome of single (SAPT) and dual antiplatelet therapy (DAPT) following fEVAR and bEVAR.

METHODS

A total of 63 patients from two German centers treated for complex aortic pathologies were included in this retrospective study. Patient data and computed tomography angiograms were analyzed. Kaplan-Meier analyses for overall survival and freedom from target vessel (TV)-related complications were performed. The outcomes were compared between SAPT versus DAPT and bEVAR versus fEVAR. Univariate logistic regression was applied to analyze the correlation between TV patency and various anatomical aortic parameters.

RESULTS

In total, 30 patients were treated with fEVAR and 33 with bEVAR. Of these, 19 patients received SAPT and 44 received DAPT postsurgery. Anatomical aortic characteristics and comorbidities were comparable among groups. Overall survival was 95% (±5.1) for SAPT and 88% (±8.8) for DAPT after 36 mo of follow-up. Patency was evaluated individually for each TV SAPT versus DAPT (celiac trunk 100% ± 0 versus 87% ± 9.6; superior mesenteric artery 86% ± 13.2 versus 100% ± 0; left renal artery 92% ± 8.0 versus 95% ± 3.6; right renal artery 72% ± 15.2 versus 81% ± 9.9). Freedom from endoleak was 35% (±13.7) for SAPT versus 30% (±13.8) for DAPT. There was no statistically significant difference for SAPT versus DAPT or for bEVAR versus fEVAR. Further, none of the anatomical aortic characteristics and bridging stent graft-related parameters analyzed predicted TV occlusion in logistic regression analysis.

CONCLUSIONS

We did not observe differences in overall survival, endoleak, and TV patency rates between SAPT and DAPT treated patients following bEVAR and/or fEVAR. Patient-specific factors therefore appear to be more relevant for the long-term outcomes rather than the antiplatelet regime applied postsurgery.

Initial Outcomes of Physician-Modified Inner-Branched Endovascular Repair for Distal Aortic Arch Aneurysm

Background/Objectives: Few clinical studies have reported on physician-modified inner-branched endovascular repair (PMiBEVAR) for aortic arch aneurysm. Herein, we evaluate the outcomes of proximal landing zone 2 PMiBEVAR. Methods: This retrospective study analyzed data from six patients who underwent zone 2 PMiBEVAR for aortic arch aneurysms at a single center between October 2021 and June 2024. The outcomes were in-hospital mortality and postoperative complications. Results: The median follow-up period was 12.5 (7.3-25) months. Males constituted four out of six cases and females constituted two out of six cases. The patients had a median age of 78.5 (76.5-79.0) years, and the aneurysm diameter was 56 (50-61) mm. Technical success was achieved in 5/6 (83.3%) cases. The median modification and operative times were 56 (45-60) min and 92 (79-308), respectively. Postoperatively, delayed type Ia endoleak and vascular access-site pseudoaneurysm occurred in one patient each. However, no patients experienced other complications. The median hospital stay was 10 (7-41) days, and no deaths or reinterventions occurred after 30 days. During the post-discharge follow-up, the aneurysm diameter remained "unchanged" in four patients, including the one with delayed type Ia endoleak, while two patients experienced "shrinkage". Conclusions: PMiBEVAR for distal aortic arch aneurysm might be effective in improving postoperative outcomes.

Multicentre retrospective analysis of physician-modified fenestrated/inner-branched endovascular repair for complex aortic aneurysms

OBJECTIVES

In this multicentre retrospective observational study, we present the early outcomes of physician-modified fenestrated/inner-branched endovascular repair for pararenal and thoracoabdominal aortic aneurysms in patients at high risk for open surgical repair.

METHODS

We comprehensively reviewed the clinical data and outcomes of consecutive patients treated with physician-modified fenestrated/inner-branched endovascular repair for pararenal or thoracoabdominal aortic aneurysms at 6 centres between December 2020 and December 2021. Primary end-points included technical success, in-hospital mortality rates, major adverse events.

RESULTS

Seven and 31 patients (median age, 80.5 years) had pararenal and thoracoabdominal aortic aneurysms, respectively, involving 93 renal-mesenteric arteries incorporated through 10 fenestrations or 83 inner branches. Seven patients (18.4%) were treated non-elective conditions. The technical success rate was 89.5%. The median operative time was 334.5 min. Ten patients (26.3%) experienced major adverse events, including in-hospital mortality in 6 patients (15.8%), acute kidney injury in 3 patients (7.9%), respiratory failure in 3 patients (7.9%), bowel ischaemia in 1 patient (2.6%), stroke in 1 patient (2.6%) and paraplegia in 1 patient (2.6%). Among elective cases, in-hospital deaths occurred in 3 patients (9.7%), while in non-elective cases, the mortality rate was higher, with 3 patients (42.9%) succumbing. The median follow-up duration was 14 months.

CONCLUSIONS

Physician-modified fenestrated/inner-branched endovascular repair is a viable treatment for pararenal or thoracoabdominal aortic aneurysms in patients at high risk for open surgical repair. It provides customization without location constraints or production delays, but further validation is needed to ensure long-term reliability.

Comparison of Biomechanical Properties of the iCover and VBX Stent Grafts When Used as Bridge Stents in Fenestrated Endografts: An In Vitro Study

OBJECTIVE

The objective of this study was to compare in vitro the different biomechanical properties of 2 balloon-expandable covered stents, VBX (Viabahn VBX, W.L. Gore & Associates, Flagstaff, AZ) and iCover (iVascular, Barcelona, Spain), as bridging stents in fenestrated aortic endoprostheses.

METHODS

Three biomechanical tests were performed to evaluate a total of 12 stents (6 VBX 6 × 59 mm and 6 iCover 6 × 57m). First, a 3-point bending test was performed with a calibrated dynamometer to evaluate the bending strength of the 40% and 150% deformation of the system in its crimped state and the force necessary to deform the expanded stent by 40% with respect to its initial diameter. Then the stents were expanded to their nominal diameter inside a 6-mm-diameter handmade fenestration and flared up to 8 and 10 mm. The whole set was fixed in the dynamometer to carry out the pullout-force (perpendicular dislocation) and shear-stress-force (axial dislocation) tests. The resulting forces were recorded via the force transducer. Load, deformation, and displacement data were recorded in newtons. The results of each stent test were examined under the microscope, and both stent types were compared.

RESULTS

Higher forces were required to bend the crimped VBX (16.24 N [IQR, 13.87-17.47 N] for the iCover and 19.01 N [IQR, 16.01-19.50 N] for VBX; P < 0.001), but lower forces were necessary for the expanded VBX compared with the iCover (0.36 N [IQR, 0.1-0.49 N] and 1.01 N [IQR, 0.97-1.09 N], respectively; p = 0.004). Pullout forces were 3.56 N (IQR, 3-4.1 N) and 7.07 N (IQR, 6.86-7.28 N) for the 8-mm flare and 7.29 N (IQR, 6.13-8.45 N) and 14 N (IQR, 12.05-15.95 N) for the 10-mm flare for the iCover and VBX, respectively (P = 0.333 for both comparisons). The shear-stress forces needed to dislocate the 6-mm iCover and VBX axially with a 10-mm flare to 50%, 100%, and 200% were 0.88, 1.61, and 3.55 N for the iCover and 0.71, 1.43, and 2.51 N for the VBX (P = 0.343, P = 0.486, and P = 0.486, respectively).

CONCLUSION

After evaluating the stents under in vitro conditions, the VBX and iCover stents showed similar results in terms of biomechanical properties, which demonstrates their competence in in vitro conditions. Further in vitro comparisons with other stent grafts are required.

CLINICAL IMPACT

The BECS used in FEVAR / BEVAR must ensure some properties to avoid the most frequent complications derived from the failure of these bridging stents (stenosis, thrombosis, stent integrity, dislodgement or endoleaks) that represent the most common cause for reintervention. This paper adds to the limited data available, information to the clinician after comparing some properties of two BECS used in these techniques that demonstrate their competence in in-vitro conditions.

Comparison of bridging stent grafts in branched endovascular aortic repair

BACKGROUND

Endovascular treatment of thoracoabdominal aortic aneurysms has become common, with satisfactory results. Nevertheless, long-term durability remains an issue mainly because of target visceral vessel (TVV) instability. Currently, no covered stent has been approved as a bridging stent graft (BSG), demanding continuous research on this topic.

METHODS

This was a multicenter observational retrospective cohort study comparing the midterm results of the Bard Covera Plus and Gore VBX as BSGs during branched endovascular aneurysm repair. The primary outcome was the comparison of the target vessel instability between the two groups. Primary patency, freedom from branch-related type I and III endoleaks and reintervention, and technical and clinical success were considered secondary outcomes. Logistic regression analysis was used to assess the association between selected baseline factors and TVV instability. TVV instability during follow-up was then evaluated using the Kaplan-Meier cumulative function.

RESULTS

Three hundred forty-five TVVs in 106 patients were considered suitable for the analysis. Two hundred twenty vessels were stented with the Covera stent graft (64%) and 125 with VBX (36%). Two hundred ninety-nine TVVs received a single BSG, 45 two BSGs, and only 1 three BSGs. Bare metal stent relining was required in 36% of TVVs, mostly in the Covera group (89 [41%] vs 36 [29%]) (P = .030). The primary technical success rate was 96% (331/345), and the assisted primary technical success rate was 99% (342/345). The TVV instability rate within 30 days was 2% (one Covera and five VBX; P = .015). Three BSG occlusions (one Covera and two VBX) and three type Ic endoleaks (three VBX) were detected. The median follow-up was 13.9 months (range, 5.8-25.5 months). Sixteen TVV instabilities were detected during the follow-up. Twelve BSG occlusions (six Covera and six VBX), three type Ic endoleaks (one Covera and two VBX), and one type IIIc endoleak (VBX). The overall target vessel instability rate was 5% (16/342). TVV instability was associated with the use of Gore VBX in the univariable logistic regression (odds ratio, 3.0; 95% confidence interval, 1.1-8.0; P = .027). Aneurysm rupture and aneurysm diameter were also associated with TVV instability in the univariable analysis (P = .002 and P = .008, respectively). The only factor predisposing to TVV instability in the multivariable logistic regression analysis was the use of Gore VBX as a BSG (odds ratio, 2.9; 95% confidence interval, 1.0-8.0; P = .043). Kaplan-Meier analysis showed a significantly higher risk of TVV instability in the VBX group (P < .001).

CONCLUSIONS

Overall midterm outcomes in this cohort were satisfactory. Patency rates were similar between the two stents. Nevertheless, VBX seems to be associated with worse TVV instability. These results may be correlated with a higher incidence of type Ic endoleaks, which require an extensive learning curve for correct stent selection and deployment.

Editor's Choice - Long Term Outcomes of the Advanta V12 Covered Bridging Stent for Fenestrated and Branched Endovascular Aneurysm Repair in 1 675 Target Vessels

OBJECTIVE

To report outcomes of the Advanta V12 as a covered bridging stent in fenestrated and branched endovascular aneurysm repair (F/BEVAR).

METHODS

Patients treated with F/BEVAR and followed in a single centre receiving the Advanta V12 as a covered bridging stent between January 2010 and May 2020 were included.

RESULTS

A total of 636 patients (543 men) were analysed. A total of 1 675 target vessels (TVs) were bridged with the Advanta V12. Estimated TV patency at one, five, and eight years was 99.1% ± 0.2%, 96.9% ± 0.5% and 96.2% ± 0.7%, respectively. Estimated patency at eight years was 98.1% ± 0.5% for fenestrations and 87.3% ± 2.9% for branches (p < .001). Estimated patency of renal arteries was statistically significantly lower for those targeted with branches compared with fenestrations (p = .001). Multivariable analysis showed that targeting a TV with a branch compared with a fenestration was the only independent risk factor for occlusion during follow up (hazard ratio 6.41, 95% CI 3.4 - 11.9; p < .001). Estimated freedom from endoleak at one, five, and eight years was 99.4% ± 0.2%, 96.4% ± 0.6%, and 95.4% ± 0.8%, respectively. Estimated freedom from target vessel instability (TVI) at one, five, and eight years was 98.5% ± 0.3%, 93.0% ± 0.8%, and 91.3% ± 1%, respectively. Estimated freedom from TVI at eight years was 93.2% ± 0.9% for fenestrations and 82.7% ± 3.5% for branches (p < .001). Estimated freedom from TVI was statistically significantly lower for renal arteries targeted with branches compared with those targeted with fenestrations (p < .001) CONCLUSION: The Advanta V12 shows excellent technical success rates as a covered bridging stent in F/ΒEVAR. Late outcomes remain good with low rates of TV occlusion, endoleak, and re-intervention. Renal arteries targeted with branches demonstrated a higher risk of occlusion and instability compared with those targeted with fenestrations.