Mid-term Outcomes and Predictors of Transarterial Embolization for Type II Endoleak After Endovascular Abdominal Aortic Aneurysm Repair

Side branch embolization before endovascular abdominal aortic aneurysm repair to prevent type II endoleak: A prospective multicenter study

PURPOSE

The purpose of the study was to evaluate the efficacy and safety of pre-emptive transcatheter arterial embolization (P-TAE) of aortic side branches to prevent type II endoleak in patients with abdominal aortic aneurysm after endovascular abdominal aneurysm repair (EVAR).

MATERIALS AND METHODS

This multicenter, prospective, single-arm trial enrolled 100 patients with abdominal aortic aneurysm from nine hospitals between 2018 and 2021. There were 85 men and 15 women, with a mean age of 79.6 ± 6.0 (standard deviation) years (range: 65-97 years). P-TAE was attempted for patent aortic side branches, including the inferior mesenteric artery, lumbar arteries, and other branches. The primary endpoint was late type II endoleak incidence at 6 months post-repair. Secondary endpoints included changes in aneurysmal sac diameter at 6- and 12 months, complications, re-intervention, and aneurysm-related mortality. Aneurysm sac changes at 6- and 12 months was compared between the late and no-late type II endoleak groups.

RESULTS

Coil embolization was successful in 80.9% (321/397) of patent aortic side branches, including 86.3% of the inferior mesenteric arteries, 80.3% of lumbar arteries, and 55.6% of other branches without severe adverse events. Late type II endoleak incidence at 6 months was 8.9% (8/90; 95% confidence interval: 3.9-16.8%). Aneurysm sac shrinkage > 5 mm was observed in 41.1% (37/90) and 55.3% (47/85) of the patients at 6- and 12-months post-EVAR, respectively. Patients with late type II endoleak had less aneurysm sac shrinkage than those without type II endoleak at 12 months (-0.2 mm vs. -6.0 mm; P = 0.040). No patients required re-intervention for type II endoleak, and no aneurysm-related mortalities occurred.

CONCLUSION

P-TAE is safe and effective in preventing type II endoleak, leading to early sac shrinkage at 12 months following EVAR.

Initial Outcomes of Embolization for Type II Endoleak: Comparison of n-Butyl Cyanoacrylate-Ethiodized Oil Mixture with n-Butyl Cyanoacrylate-Ethiodized Oil-Ethanol Mixture

PURPOSE

To compare the safety and effectiveness of n-butyl cyanoacrylate (nBCA)-ethiodized oil (NE) mixture and nBCA-ethiodized oil-ethanol (NEE) mixture embolization for Type II endoleak (T2EL) after endovascular aortic repair.

MATERIALS AND METHODS

This study included 32 patients with 49 procedures who underwent T2EL embolization between January 2008 and June 2022. Cases with no follow-up after embolization, technical failure, treatment with coil only, Type I endoleak at the embolization, and re-embolization were excluded. The resultant final cohort included 24 patients (14 men and 10 women; mean age, 83.3 years [interquartile range, 77-89 years]) who underwent initial T2EL embolization, with 15 patients in the NE group and 9 patients in the NEE group. The 2 groups were compared in terms of adverse events (AEs), freedom from sac enlargement, and freedom from reintervention.

RESULTS

The follow-up period after embolization for T2EL was 960 days (SD ± 1,007) in the NE group and 484 days (SD ± 192) in the NEE group, without significant differences. No AEs above moderate were observed in either group. The rate of freedom from sac enlargement at 1 year was 65.0% in the NE group and 87.5% in the NEE group (P = .03). The rate of freedom from reintervention at 1 year was 69.2% in the NE group and 100.0% in the NEE group (P = .02).

CONCLUSIONS

The NEE group had significantly higher rates of freedom from sac enlargement and reintervention at 1 year compared with the NE group. These results suggest that T2EL embolization with NEE may be more effective than that with NE.

Remodeling of the Proximal Sealing Zone and Sac Shrinkage after Endovascular Aortic Repair or Fenestrated Endovascular Aortic Repair

BACKGROUND

Variations in sac shrinkage (SS) are noted between endovascular aneurysm repair for abdominal aortic aneurysm (AAA) and fenestrated endovascular aneurysm repair for short neck AAA. These variations may originate from difference in the geometry and length of proximal sealing, which influences the quality and durability of the seal. This study aimed to explore the disparities in aneurysm exclusion and sac remodeling across these 2 scenarios.

METHODS

This study involved a retrospective analysis of prospectively collected data from 2014 to 2021. Of 486 endovascular abdominal aortic repair cases, 33 that exclusively used a low permeability expanded polytetrafluoroethylene infrarenal device, strictly adhering to the instructions for use (IFUs), were selected. Concurrently, 30 cases of fenestrated repair that utilized modified polyester woven fabric devices proximally with consistent use of the aforementioned low-permeability devices infrarenally were examined. The quality of both proximal and distal sealing zones in fenestrated repairs was maintained within the range specified in the expanded polytetrafluoroethylene infrarenal device's IFUs, ensuring consistent sealing integrity for reliable group comparisons. Key metrics used for analysis were the detection of endoleaks and measurements of sac dimensions. Additional analyses included comparisons of demographic data and postoperative diameter changes in the proximal sealing zone (PZ) (encompassing 0, 5, 10, 15, and 20 mm below the most proximal sealing stent).

RESULTS

The demographic data and preoperative maximum-minimum diameter of the aneurysms did not differ between the groups. Proximal neck dilatation was similarly observed after both procedures. Immediately after the procedure, the incidence of lumbar arterial type II endoleaks was significantly lower after fenestrated repair than that after endovascular aortic repair (EVAR, 10% vs. 39.4%, P = 0.0094). At the final observation, EVAR substantially reduced the PZ length (-4.73 ± 15.30%), while fenestrated repair maintained the length (21.98 ± 24.34%; P < 0.0001). The preservation of the sealing length in fenestrated repairs was attributable to dilation occurring within the sealing range of the proximal device, oversized to accommodate the larger diameters in the more proximal sections of the aorta. The cumulative occurrence of SS (>5 mm) following fenestrated repair increased faster than that after endovascular repair (P = 0.002).

CONCLUSIONS

Although aortic neck dilatation progressed similarly in both groups, fenestrated repair maintained the sealing length and demonstrated a greater extent of SS, even under the challenging circumstances in PZ. The superior postoperative results were linked to both the durability of proximal sealing and a lower occurrence of lumbar arterial type II endoleaks, stemming from the effective shuttering of the collateral sources in the proximal lumbar or intercostal arteries.

Preemptive Embolization of Abdominal Aortic Aneurysm Sac Side Branch Arteries Promotes Early Sac Shrinkage after Endovascular Aneurysm Repair 1

BACKGROUND

The association between the occlusion rate of the side branch arteries branching from the abdominal aortic aneurysm sac and aneurysm sac shrinkage is unclear. We aimed to evaluate the efficacy of preemptive embolization of multiple side branch arteries branching from the abdominal aortic aneurysm sac in early aneurysm sac shrinkage after endovascular aneurysm repair.

METHODS

Patients undergoing endovascular aneurysm repair of abdominal aortic aneurysms, with or without preemptive embolization of multiple side branch arteries, including the inferior mesenteric artery and lumbar arteries, between January 2016 and August 2021, were retrospectively evaluated. Preemptive embolization was introduced at our institution in January 2018 and has been performed in all patients who undergo endovascular aneurysm repair since then. We compared occlusion rates of the side branch arteries, frequency of type 2 endoleaks, changes in aneurysm sac size, percentage of aneurysm sac size decrease, and frequency of reduction in the aneurysm sac diameter by > 5 mm.

RESULTS

The study included 43 patients in the embolization group and 20 in the nonembolization group. Preemptive embolization was successfully performed without any ischemic complications. The total occlusion rate of side branch arteries was significantly higher in the embolization group than in the nonembolization group (70.2% vs. 29.3%, P < 0.05). At 24 months of follow-up, the type 2 endoleak frequency was significantly lower in the embolization group than in the nonembolization group (6.9% vs. 31.6%, P < 0.05). The frequency of reduction in the aneurysm sac diameter by > 5 mm was significantly higher in the embolization group than in the nonembolization group at 24 months (62.1% vs. 31.6% P < 0.05). The optimal cutoff value for the total occlusion rate of the side branch arteries to achieve reduction in the aneurysm sac diameter by > 5 mm at 24 months, after endovascular aneurysm repair, was 66.7% in all patients (area under the curve = 0.634; sensitivity = 62.5%; specificity = 70.8%). These findings suggest that occluding 66.7% or more of the side branch arteries may result in early aneurysmal shrinkage.

CONCLUSIONS

Preemptive embolization of multiple side branch arteries, branching from the abdominal aortic aneurysm sac, may contribute to early aneurysm sac shrinkage; this may serve as a marker for fewer late complications after endovascular aneurysm repair.

Open Conversion with Explantation of Stent Grafts After Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm

BACKGROUND

Although endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) is widely used worldwide, the fact that it is associated with increased rates of reintervention has been considered a problem. This study aimed to analyze the outcomes of primary open AAA repair and open conversion with explantation of stent grafts after EVAR.

METHODS

In this retrospective study, we enrolled 1,120 patients (open repair, n = 664; EVAR, n = 456) who underwent AAA repair at Kobe University from 1999 to 2019. Of the 664 patients who underwent open repair, 121 (patients who underwent primary open repair (POR) as a concomitant procedure and patients with ruptured AAA) were excluded from the study. The outcomes of POR were compared with those of open conversion with explantation of stent grafts.

RESULTS

Of the 543 patients who underwent open repair, 513 underwent POR and 30 underwent open conversion with explantation of stent grafts. The operation time for POR was significantly less than that for open conversion with explantation. During surgery, patients who underwent open conversion with explantation required significantly more transfusions of red cell concentrate, fresh frozen plasma, and platelet concentrate than those who underwent POR. Overall, 30 patients who underwent open conversion with explantation required a total of 48 reinterventions before surgery. Hospital mortality rates were 0.7% and 0% in the POR and open conversion with explantation groups, respectively (P = 0.62). Although overall survival at 5 years in the POR group was significantly better than that in the open conversion with explantation group (89.3 ± 1.7% vs. 79.5 ± 9.6%; P = 0.01), there were no significant differences between the 2 groups regarding the freedom from aortic event (hospital death, reintervention, and aortic death). According to the multivariate analysis, open conversion with explantation was not an independent risk factor for late death. There were 20 patients who were hesitant to undergo OCE, although we recommended OCE. In a subgroup analysis, the overall mean cost borne by patients who underwent EVAR was approximately 2.3 times higher compared with that borne by patients who underwent POR.

CONCLUSIONS

Although demanding, both early and long-term outcomes of OCE have been favorable in our present study. OCE is highly recommended in patients with persistent sac enlargement after EVAR.

Pre-emptive Aortic Side Branch Embolization during Endovascular Aneurysm Repair Using the Excluder Stent-Graft System: A Prospective Multicenter study

PURPOSE

To evaluate the effectiveness and safety of pre-emptive transcatheter arterial embolization (P-TAE) for aortic side branches (ASBs) to prevent Type 2 endoleaks (EL2) before endovascular aneurysm repair (EVAR) using the Excluder stent-graft system (Excluder).

MATERIALS AND METHODS

In this prospective, multicenter study, 80 patients (mean age, 79.1 years [SD ± 6.7]; 85.0% were men; mean aneurysmal sac diameter, 48.4 mm [SD ± 7.4]) meeting the eligibility criteria were prospectively enrolled from 9 hospitals. Before EVAR, P-TAE was performed to embolize the patent ASBs originating from the abdominal aortic aneurysm. Contrast-enhanced computed tomography (CT) was performed at 1 month and 6 months after EVAR. The primary endpoint was EL2 incidence at 6 months, and the secondary endpoints were aneurysmal sac diameter changes at 6 and 12 months, P-TAE outcomes, adverse events related to P-TAE, reintervention, and aneurysm-related mortality.

RESULTS

All patients successfully underwent P-TAE without serious. Coil embolization was successful in 81.6% of ASBs. EL2 incidence at 6 months was identified in 18 of 70 (25.7%) patients. Aneurysmal sac diameter shrinkage (≥5 mm) was observed in 30.0% of patients at 6 months and in 40.9% at 12 months. Only 1 patient required reintervention for EL2 within 1 year of EVAR; aneurysm-related deaths were not observed.

CONCLUSIONS

P-TAE for ASBs before EVAR using Excluder is a safe and effective strategy. It aids in achieving early aneurysmal sac shrinkage and reduces EL2 reintervention at 1 year after EVAR.

CIRSE Standards of Practice on Management of Endoleaks Following Endovascular Aneurysm Repair

BACKGROUND

Endoleaks represent the most common complication after EVAR. Some types are associated with ongoing risk of aneurysm rupture and necessitate long-term surveillance and secondary interventions.

PURPOSE

This document, as with all CIRSE Standards of Practice documents, will recommend a reasonable approach to best practices of managing endoleaks. This will include imaging diagnosis, surveillance, indications for intervention, endovascular treatments and their outcomes. Our purpose is to provide recommendations based on up-to-date evidence, updating the guidelines previously published on this topic in 2013.

METHODS

The writing group was established by the CIRSE Standards of Practice Committee and consisted of clinicians with internationally recognised expertise in endoleak management. The writing group reviewed the existing literature performing a pragmatic evidence search using PubMed to select publications in English and relating to human subjects up to 2023. The final recommendations were formulated through consensus.

RESULTS

Endoleaks may compromise durability of the aortic repair, and long-term imaging surveillance is necessary for early detection and correct classification to guide potential re-intervention. The majority of endoleaks that require treatment can be managed using endovascular techniques. This Standards of Practice document provides up-to-date recommendations for the safe management of endoleaks.

Long-Term Outcomes of Simple Endovascular Aneurysm Repair Based on the Initial Aortic Diameter

PURPOSE

We aimed to investigate the effects of initial abdominal aortic aneurysm (AAA) diameter on aneurysmal sac expansion/shrinkage, endoleaks, and reintervention postelective simple endovascular aneurysm repair (EVAR).

METHODS

Overall, 228 patients monitored for >1 year after EVAR were analyzed. Male and female participants with initial AAA diameters <55 mm and <50 mm, respectively, composed the small group (group S), while those with initial AAA diameters ≥55 mm (men) and ≥50 mm (women) composed the large group (group L). Aneurysmal sac expansion of 10 mm and/or reintervention during follow-up (composite event) and its related factors were evaluated.

RESULTS

The 5-year freedom from composite event rate was significantly higher in group S (92.4 ± 2.8%) than that in group L (79.1 ± 4.9%; P <0.01). Multivariate analysis revealed AAA diameters before EVAR in group S (hazard ratio, 0.38; 95% confidence interval, 0.18-0.81; P = 0.01) and type II endoleak (T2EL) at discharge (hazard ratio, 2.83; 95% confidence interval, 1.29-6.20; P <0.01) as factors associated with the composite event. The freedom from composite event rate decreased to 51 ± 13% at 5 years in group L with T2EL.

CONCLUSIONS

Group S had high freedom from composite event rate; in group L, the rate decreased to 51% at 5 years with T2EL at discharge.

Preemptive Embolization of the Lumbar Arteries and Inferior Mesenteric Artery to Prevent Abdominal Aortic Aneurysm Enlargement Associated with Type 2 Endoleak Following Endovascular Aneurysm Repair

Purpose

This study aims to evaluate the efficacy of preemptive embolization (PE) of the lumbar arteries (LAs) and inferior mesenteric artery (IMA) (PELI) for preventing abdominal aortic aneurysm (AAA) enlargement associated with type 2 endoleak (T2EL).

Material and Methods

Patients who underwent endovascular aneurysm repair (EVAR) between January 2015 and December 2020 were classified into the control (without PE), IMA (PE of a patent IMA with a diameter ≥2.5 mm), and PELI (PE of patent LAs with a diameter ≥2 mm and IMA) groups. The rate of freedom from AAA enlargement following EVAR (enlargement ≥5 mm from pre-EVAR) was compared using the log-rank test. The prevalence of T2EL at 6 months and 1 year after EVAR was compared using Fisher's exact test.

Results

The cumulative rates of freedom from AAA enlargement at 54 months after EVAR (maximum observational period in the PELI group) were as follows: control group, 77.5%; IMA group, 62.5%; and PELI group, 100%. The mean CT follow-up periods of the control, IMA, and PELI groups were 46.4 ± 22.3, 31.1 ± 20.6, and 22.9 ± 15.5 months, respectively. None of the 31 patients in the PELI group experienced AAA enlargement after EVAR, whereas 2 out of the 16 patients in the IMA group and 20 out of the 98 patients in the control group had AAA enlargement. No significant differences were observed in the rate of freedom from AAA enlargement (PELI group vs. IMA group, P = 0.11; PELI group vs. control group, P = 0.11). The prevalence of T2EL was significantly lower in the PELI group than in the control group at 6 months (13.6% in PELI group vs. 42.1% in control group, P = 0.02) and 1 year (14.3% in PELI group vs. 40.0% in control group, P = 0.04).

Conclusions

PELI was significantly associated with a low prevalence of T2EL and may prevent T2EL-associated AAA enlargement.

Midterm Outcomes of Endoleak Type 2 Embolization after Endovascular Aortic Aneurysm Repair Using a Neurointerventional Approach

BACKGROUND

Type 2 endoleaks (T2ELs) have been considered a benign condition and intervention is recommended when they are associated to sac expansion. The aim of this study was to report on T2EL embolization midterm outcomes, using neurointerventional material.

METHODS

A single-center retrospective analysis of consecutive patients treated with transarterial embolization, using neurointerventional material, for T2EL after standard endovascular aortic aneurysm repair (EVAR) between January 01, 2017 and July 30, 2022, was undertaken. Primary outcome was technical success and secondary outcome was T2EL recurrence during follow-up.

RESULTS

Twenty six patients [92.3% males, mean age 73.9 ± 7.7 years] were included. The median time between EVAR and T2EL diagnosis was 12 months (range: 1-84 months). In 38.5% of patients, T2EL was detected at first month after EVAR. The time to embolization was 18 months (range: 1-96 months). In 42.3% of cases, a patent inferior mesenteric artery was suspected to relate to T2EL formation while in 42.3% of cases, a lumbar artery. Twelve procedures (38.4%) were performed using coils and Onyx and 13 (50%), using only Onyx. Technical success was 84.6%. The mean follow-up was 24 months (range: 1-60 months), including 20 patients. In 30% of cases, an T2EL recurrence was detected. Three patients (11.5%) underwent secondary embolization.

CONCLUSIONS

Transarterial embolization for T2EL, using neurointerventional material, provided acceptable technical success and T2EL recurrence rates at 2 years of follow-up. Longer follow-up data would further estimate the durability of the technique.

Outcomes of embolization procedures for type II endoleaks following endovascular abdominal aortic repair

OBJECTIVE

The objective of this study was to investigate the mid-term outcomes of embolization procedures for type II endoleak after endovascular abdominal aortic repair, and clarify the risk factors for aneurysm enlargement after embolization procedures.

METHODS

This was a retrospective multicenter registry study enrolling patients who underwent embolization procedures for type II endoleaks after EVAR from January 2012 to December 2018 at 19 Japanese centers. The primary end point was the rate of freedom from aneurysm enlargement, more than 5 mm in the aortic maximum diameter, after an embolization procedure. Demographic, procedural, follow-up, and laboratory data were collected. Continuous variables were summarized descriptively, and Kaplan-Meier analyses and a Cox regression model were used for statistical analyses.

RESULTS

A total of 315 patients (248 men and 67 women) were enrolled. The average duration from the initial embolization procedure to the last follow-up was 31.6 ± 24.6 months. The rates of freedom from aneurysm enlargement at 3 and 5 years were 55.4 ± 3.8% and 37.0 ± 5.2%, respectively. A multivariate analysis revealed that a larger aortic diameter at the initial embolization procedure and the presence of a Moyamoya endoleak, defined as heterogeneous contrast opacity with an indistinct faint border, were associated with aneurysm enlargement after embolization management.

CONCLUSIONS

The embolization procedures were generally ineffective in preventing further expansion of abdominal aortic aneurysms in patients with type II endoleaks after EVAR, especially in patients with a large abdominal aortic aneurysm and/or a presence of a Moyamoya endoleak.

[Endoleaks in endovacular treatment of infrareneral abdominal aortic aneurysm (part I)]

We analyzed the PubMed, Scopus databases and the eLIBRARY electronic library regarding appropriate literature data. In the first part, modern classifications of endoleaks type 1 and 2 after stenting of infrarenal aortic aneurysm are considered. We described causes, risk factors and effectiveness of various treatment options.

Recent Update of Endovascular Type 2 Endoleak Management

EVAR has been used clinically for almost three decades, and it has been widely applied in clinical practice and has been applied to difficult cases as devices and techniques have evolved. Although the major advantage of EVAR is its lower perioperative mortality, compared with open surgery, late-onset complications such as endoleaks have become major issues, requiring lifelong follow-up after EVAR. The clinical guidelines have been updated, and many systematic reviews/meta-analyses and multi-center registries have been published; surgeons must keep up-to-date regarding these changes. In this review, the author reviews evidence on the recent update of the type 2 endoleak management.