Persistent type 2 endoleak after endovascular repair of abdominal aortic aneurysm is associated with adverse late outcomes

Impact of the Patency of Inferior Mesenteric Artery on 7-Year Outcomes After Endovascular Aneurysm Repair

PURPOSE

The impact of preoperative patent inferior mesenteric artery (IMA) on late outcomes following endovascular aneurysm repair (EVAR) remains unclear. This study aimed to investigate the specific influence of IMA patency on 7-year outcomes after EVAR.

MATERIALS AND METHODS

In this retrospective cohort study, 556 EVARs performed for true abdominal aortic aneurysm cases between January 2006 and December 2019 at our institution were reviewed. Endovascular aneurysm repairs performed using a commercially available device with no type I or type III endoleak (EL) during follow-up and with follow-up ≥12 months were included. A total of 336 patients were enrolled in this study. The cohort was divided into the patent IMA group and the occluded IMA group according to preoperative IMA status. The late outcomes, including aneurysm sac enlargement, reintervention, and mortality rates, were compared between both groups using propensity-score-matched data.

RESULTS

After propensity score matching, 86 patients were included in each group. The median follow-up period was 56 months (interquartile range: 32-94 months). The incidence of type II EL at discharge was 50% in the patent IMA group and 19% in the occluded IMA group (p<0.001). The type II EL from IMA and lumbar arteries was significantly higher in the patent IMA group than in the occluded IMA group (p<0.001 and p=0.002). The rate of freedom from aneurysm sac enlargement with type II EL was significantly higher in the occluded IMA group than in the patent IMA group (94% vs 69% at 7 years; p<0.001). The rate of freedom from reintervention was significantly higher in the occluded IMA group than in the patent IMA group (90% vs 74% at 7 years; p=0.007). Abdominal aortic aneurysm-related death and all-cause mortality did not significantly differ between groups (p=0.32 and p=0.34).

CONCLUSIONS

Inferior mesenteric artery patency could affect late reintervention and aneurysm sac enlargement but did not have a significant impact on mortality. Preoperative assessment and embolization of IMA might be an important factor for improvement in late EVAR outcomes.

CLINICAL IMPACT

The preoperative patency of the inferior mesenteric artery was significantly associated with a higher incidence of sac enlargement and reintervention with type II endoleak following endovascular aneurysm repair, even after adjustment for patient background. Preoperative assessment and embolization of inferior mesenteric artery might be an important factor for improvement in late EVAR outcomes.

Direct sac puncture versus transarterial embolization of type II endoleaks after endovascular abdominal aortic aneurysm repair: Comparison of outcomes

PURPOSE

Type 2 endoleak (T2EL) is the most common type of endoleak after endovascular abdominal aortic aneurysm repair (EVAR), and increases the risk of aneurysm sac rupture if it persists beyond 6 months. The purpose of this study is to compare the efficacy and safety of direct sac puncture versus transarterial embolization of T2ELs.

METHODS

Retrospective review of 42 consecutive T2EL embolization procedures, 19 by DSP and 23 by transarterial technique, between January 2015 and December 2020. Primary outcome was aneurysm sac stability and resolution of endoleak at follow-up imaging. Adverse events (AE) were classified based on the Society of Interventional Radiology (SIR) practice guidelines.

RESULTS

Technical success was 94.7% (18/19) in the DSP group and 86.9% (20/23) in the transarterial group (p = 0.32 (-0.77-0.25)). Treatment efficacy was evaluated in 16 patients in the DSP group and 18 patients in the transarterial group who had follow-up imaging ≥6 months after embolization. Mean imaging follow-up was 17.1 ± 11.2 (range, 6-41) months in the DSP group and 26.5 ± 15.4 (range, 6-48) months in the transarterial group (p = 0.06, -19.24-0.37). Treatment efficacy was 75% (12/16) in the DSP group and 33.3% (6/18) in the transarterial group (p = 0.02, 95% CI, 0.09-0.97). There was no procedure-related mortality. Moderate-severe AE occurred in 15.7% (3/19) in the DSP group and 8.7% (2/23) in the transarterial group (p = 0.44, -0.12-0.26).

CONCLUSION

In this study, DSP embolization of T2EL was equally safe and more effective than transarterial embolization in achieving aneurysm sac stability and resolution of endoleak.

Contrast-Enhanced Ultrasound after Endovascular Aortic Repair: Supplement and Potential Substitute for CT in Early- and Long-Term Follow-Up

BACKGROUND

Endoleaks are the most common complication after endovascular aneurysm repair (EVAR). Computed tomography angiography (CTA) is presently the golden standard for lifelong surveillance after EVAR. Several studies and meta-analyses have shown contrast-enhanced ultrasound (CEUS) to be a good alternative. The main goal of our study was to further validate the inclusion of CEUS in follow-up examination protocols for the systematic surveillance after EVAR.

METHODS

A retrospective analysis of patients who had received CEUS as part of their routine surveillance after EVAR at our center was conducted. Detection rate and classification of endoleak types were compared between available postinterventional CTA/magnetic resonance angiography and follow-up CEUS examinations. Last preinterventional CTAs before EVAR served as baselines with focus on potential cofactors such as age, body mass index, maximum aortic aneurysm diameters, endoleak orientation, and distance-to-surface influencing detection rates and classification.

RESULTS

In total, 101 patients were included in the analysis. Forty-four endoleaks (43.5% of cases) were detected by either initial CEUS or CTA, mostly type II (37.6% of the included patients). Initial CEUS showed an endoleak sensitivity of 91.2%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 84.6%. No covariate with an influence on the correct classification could be identified either for CEUS or CT.

CONCLUSIONS

CEUS should be considered a valid complementary method to CTA in the lifelong surveillance after EVAR. As type II endoleaks seem to be a common early-term, sometimes spontaneously resolving complication that can potentially be missed by CTA, we suggest combined follow-up protocols including CEUS in the early on postinterventional assessment.

Laparoscopic Ligation of the Inferior Mesenteric Artery: A Systematic Review of an Emerging Trend for Addressing Type II Endoleak Following Endovascular Aortic Aneurysm Repair

Background/Objectives: this systematic review aims to explore the efficacy and safety of the laparoscopic ligation of the inferior mesenteric artery (IMA) as an emerging trend for addressing a type II endoleak following endovascular aortic aneurysm repair (EVAR). Methods: A comprehensive literature search was conducted across several databases including Medline, Scopus, and the Cochrane Central Register of Controlled Trials, adhering to the PRISMA guidelines. The search focused on articles reporting on the laparoscopic ligation of the IMA for the treatment of a type II endoleak post-EVAR. Data were extracted regarding study characteristics, patient demographics, technical success rates, postoperative outcomes, and follow-up results. Results: Our analysis included ten case studies and two retrospective cohort studies, comprising a total of 26 patients who underwent a laparoscopic ligation of the IMA between 2000 and 2023. The mean age of the cohort was 72.3 years, with a male predominance (92.3%). The mean AAA diameter at the time of intervention was 69.7 mm. The technique demonstrated a high technical success rate of 92.3%, with a mean procedure time of 118.4 min and minimal blood loss. The average follow-up duration was 19.9 months, with 73% of patients experiencing regression of the aneurysmal sac, and no reports of an IMA-related type II endoleak during the follow-up period. Conclusions: The laparoscopic ligation of the IMA for a type II endoleak following EVAR presents a promising, minimally invasive alternative with high technical success rates and favorable postoperative outcomes. Despite its potential advantages, including reduced contrast agent use and radiation exposure, its application remains limited to specialized centers. The findings suggest the need for further research in larger prospective studies to validate the effectiveness of this procedure and potentially broaden its clinical adoption.

Implications and late outcomes of type II endoleaks after endovascular aneurysm repair

OBJECTIVE

Type II endoleaks (T2ELs) are the most common cause of reintervention after endovascular aneurysm repair (EVAR). Although most resolve spontaneously, the long-term implications of T2ELs remain elusive. We aim to evaluate the impact of persistent and late T2ELs on clinical outcomes after EVAR.

METHODS

This was a single-institution retrospective review of patients who underwent EVAR for degenerative infrarenal abdominal aortic aneurysm between January 2010 and June 2022 with no type I (T1EL) or III (T3EL) endoleak seen at EVAR completion. Patients were categorized based on T2EL status. Group 1 included patients with never detected or transient T2ELs (detected at EVAR completion but not after). Group 2 encompassed persistent T2ELs (seen at EVAR completion and again during follow-up) and late T2ELs (detected for the first time at any point during follow-up). Time-to-event analysis was conducted using a time-dependent approach to T2EL status. Primary outcomes included freedom from sac enlargement (SE), aneurysm-related reinterventions, and overall survival.

RESULTS

A total of 803 patients met inclusion criteria. Group 1 included 418 patients (52%), of which 85% had no T2ELs and 15% had transient T2ELs. Group 2 had 385 patients; 23% had persistent T2ELs, and 77% developed a new T2EL. Patients in group 1 had a higher prevalence of smoking (88% vs 83%; P < .001), chronic obstructive pulmonary disease (33% vs 25%; P = .008), chronic kidney disease (13% vs 8%; P = .021), and a higher mean Society for Vascular Surgery score (7 vs 6 points; P = .049). No differences were found in aneurysm diameter or morphology. Mean follow-up was 5 years for the entire cohort. In Group 2, 58 patients (15%) underwent T2EL treatment, most commonly transarterial embolization. At 10 years after EVAR, Group 2 was associated with lower freedom from SE (P < .001) and abdominal aortic aneurysm-related reinterventions (P < .001) and comparable overall survival (P = .42). More T1ELs were detected during follow-up in Group 2 (6 [1%] vs 20 [5%]; P = .004), with 15 (75%) of these detected at a median of 3 years after the T2EL. No difference between groups was observed in explant (0.7% vs 2.1%; P = .130) or aneurysm rupture (0.5% vs 1.3%; P = .269) rates.

CONCLUSIONS

One-half of patients treated with infrarenal EVAR developed persistent/late T2ELs, which are associated with a higher risk of SE and reinterventions. No difference in overall survival or aneurysm rupture risk was seen at 10 years, based on T2EL status or T2EL intervention. A conservative approach to T2ELs may be appropriate for most patients with absent T1ELs or T3ELs.

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.

Image Guidance Techniques and Treatment Approach Optimization in the Management of Type-II Endoleak After Endovascular Aortic Aneurysm Repair

BACKGROUND

Over the past 3 decades endovascular aortic aneurysm repair emerged as the primary approach for abdominal aortic aneurysm management, however the occurrence of endoleak following endograft implantation imposes a high toll on patients and hospitals alike. The early diagnosis and appropriate treatment of endoleaks is associated with better outcomes, which calls for more advanced imaging and a standardized approach for endoleak diagnosis and management following endovascular aortic aneurysm repair. Although conventional strategy with non-targeted deployment of coils and embolic material in the aneurysm sac is considered to be the standard approach in many hospitals, it may not prove to be a viable option, given that it affects any further follow-up imaging in the event of sub-optimal therapy and consequent recurrence.

METHODS

Based on our tertiary aortic referral center experience we summarize and describe strategies for optimal selection of various treatment approaches for Type-II Endoleak management including endovascular, percutaneous and laparoscopic approaches with particular focus on intraoperative image guidance techniques.

RESULTS

After failed conventional endovascular embolization attempt we recommend specific complex type II endoleak management approaches based on the location of the endoleak within the aneurysm sac along the x, y and z axis. A transabdominal or laparoscopic approach enable treatment in endoleaks located in the anterior portion of the sac. Endoleaks in the posterior portion of the sac could be treated using the transcaval or the translumbar approach, depending on whether the endoleak is situated on the left or the right side. Alternative strategies should be considered if patient anatomy does not allow for either transcaval or translumbar approach. The transgraft technique is reserved for endoleaks located in the cranial portion of the sac, while the perigraft approach could present a means of treatment for endoleaks situated in the caudal portion of the aneurysm sac.

CONCLUSION

We encourage establishing a patient specific treatment plan in accordance with individual anatomy based on cross sectional imaging modality (time resolved dynamic imaging in selected cases) and intraoperative image guidance to provide a safe and accurate endoleak localization and embolization for patients undergoing type II endoleak treatment.

Initial two-day blood pressure management after endovascular aneurysm repair improves midterm outcomes by reducing the incidence of early type II endoleak

OBJECTIVE

The aim of this study was to evaluate midterm outcomes of our novel strategy of postoperative initial 2-day blood pressure management (BPM) after endovascular aneurysm repair (EVAR) for the prevention of subsequent type II endoleak (T2EL) in a single-center series.

METHODS

Between 2008 and 2014, 137 patients who underwent EVAR for abdominal aortic aneurysm (AAA) were reviewed. Starting from 2013, the mean blood pressure was maintained between 75 and 90 mmHg for the initial 24 hours after EVAR followed by systolic pressure controlled below 120 mmHg during the next 24 hours in the treatment group (n = 76). The incidence of T2EL detected at 7 days, reintervention, and AAA sac diameter up to 5 years after EVAR were compared with those of the control group comprising of 60 consecutive patients who underwent standard EVAR without BPM prior to 2013.

RESULTS

Between the treatment group and the control group, significant differences were achieved in the incidence of T2EL at 7 days (19.7% vs 40.0%; P = .009), a mean decrease of AAA sac diameter at 1-year (-5.1 ± 4.9 vs -2.2 ± 6.7 mm; P = .013) and 2-year (-5.4 ± 7.7 vs -1.7 ± 10.8 mm; P = .045). In addition, there was a significant decrease in the incidence of T2EL detected at 7 days with the use of the Gore Excluder with 22.7% in the treatment group vs 80.0% in the control group (P < .001), which resulted in a significant decrease in the aneurysm sac diameter up to 4 years after EVAR. Survival rate without AAA sac enlargement at 5 years after EVAR (83.0% vs 70.0%; P = .021) in the treatment group was significantly higher than that of the control group, whereas no significant differences were observed in the freedom rates of reintervention, T2EL-related reintervention, and all-cause mortality between the groups.

CONCLUSIONS

Postoperative initial 2-day BPM had a preventive effect on AAA sac enlargement until midterm periods, by reducing the incidence of T2EL at 7 days after EVAR. The usage of Gore Excluder under BPM was especially associated with sustained positive effects until the midterm follow-up.

Injection of n-Butyl-2-Cyanoacrylate into the Abdominal Aortic Aneurysm Sac during Endovascular Aortic Repair to Prevent Type II Endoleaks Caused by Lumbar Arteries

PURPOSE

To evaluate midterm results of whether the strategy to occlude target lumbar arteries using n-butyl-2-cyanoacrylate (nBCA) injection during endovascular aneurysm repair (EVAR) reduced the incidence of Type II endoleak (T2EL) after EVAR.

MATERIALS AND METHODS

Between 2013 and 2020, 187 patients underwent EVAR; 106 in the treatment group received nBCA injection during EVAR, whereas 81 in the historical control group did not. The incidence of T2EL at 7 days, need for reintervention, and post-EVAR aneurysmal shrinkage were compared between the groups.

RESULTS

Between the treatment group and the control group, significant differences were achieved in the incidence of T2EL (2.8% vs 28.4%; P < .0001) and decreased aneurysmal diameter was observed at 1 year after EVAR (-5.2 vs -3.8 mm; P = .034). In multivariate analysis, nBCA injection (odds ratio [OR], 0.04; P = .001) and younger age (OR, 0.92; P = .036) were significantly associated with a reduced incidence of T2EL. As a possible adverse event associated with nBCA injection, 2 cases of transient lower-limb motor dysfunction (1.9%) were observed. Propensity score analysis revealed that the treatment group had a significantly lower incidence of T2EL than that in the control group (P = .0002) even though there was no difference in the incidence of inferior mesenteric artery coil embolization between the groups. The survival rate without aneurysm sac enlargement (100.0% vs 69.8%; P = .014) and the reintervention-free rate (100.0% vs 63.1%; P = .034) in the treatment group were significantly higher than those in the control group.

CONCLUSIONS

Concomitant nBCA injection can provide durable EVAR without T2EL, as supported by the avoidance of reintervention associated with aneurysm sac enlargement.

Systematic Review and Meta-Analysis of the Effect of Anticoagulation on Outcomes After Endovascular Aneurysm Repair

PURPOSE

Our objective was to investigate whether patients who receive anticoagulation therapy have different outcomes after endovascular aneurysm repair (EVAR) from those who do not.

MATERIALS AND METHODS

We conducted a systematic review of studies that compared outcomes of EVAR in patients who were on therapeutic anticoagulation vs those who were not. We developed and reported the review in accordance with the PRISMA guidelines with a registered protocol (CRD42022375894). The Ovid interface was used to search Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica Database (EMBASE), and Cochrane Central Register of Controlled Trials (CENTRAL) up to November 2022. The quality of studies was assessed with the Newcastle-Ottawa Scale (NOS) (maximum score=9), and the evidence was appraised with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. The hazard ratio (HR) and 95% confidence interval (CI) was the effect estimate in time-to-event meta-analyses, calculated using the inverse-variance statistical method and random-effects models.

RESULTS

Sixteen studies qualified for inclusion reporting a total of 35 739 individuals. Anticoagulated patients had a statistically significantly higher hazard of death (HR=1.93, 95% CI=1.03-3.63), endoleak (HR=2.13, 95% CI=1.55-2.93), reintervention (HR=1.79, 95% CI=1.27-2.52), and aneurysm sac expansion (HR=2.72, 95% CI=1.57-4.72) than patients not receiving anticoagulation therapy. The median score on the NOS was 7 (range=4-9). The certainty of evidence was very low for mortality and reintervention and low for endoleak and sac expansion.

CONCLUSIONS

Anticoagulation is a poor prognostic factor after standard EVAR and should be considered in decision-making, consent processes, and surveillance strategies.

CLINICAL IMPACT

The number of individuals who take anticoagulation treatment has been rapidly increasing over the recent years. We aimed to investigate the effect of such treatment on outcomes after endovascular aneurysm repair (EVAR). Anticoagulated patients were found to have increased mortality, endoleak, and reintervention rates after EVAR compared to their non-anticoagulated counterparts. Anticoagulation therapy has a prognostic role in EVAR and should be considered in decision making and EVAR surveillance. Anticoagulated patients need to be informed of the higher failure rates of EVAR, and intensified surveillance strategies may need to be implemented in this patient cohort.

Impact of Patent Lumbar Arteries on Aneurysm Sac Enlargement with Type II Endoleak after Endovascular Aneurysm Repair

OBJECTIVE

This study aimed to investigate the impact of the number of patent lumbar arteries (LAs) on sac enlargement after endovascular aneurysm repair (EVAR).

METHODS

This was a retrospective cohort single centre registry study. Between January 2006 and December 2019, 336 EVARs were reviewed using a commercially available device excluding type I or type III endoleaks during a follow up of ≥ 12 months. Patients were divided into four groups based on the pre-operative patency of the inferior mesenteric artery (IMA) and high (≥ 4) or low (≤ 3) number of patent LAs: Group 1, patent IMA and high number of patent LAs; Group 2, patent IMA and low number of patent LAs; Group 3, occluded IMA and a high number of patent LAs; Group 4, occluded IMA and low number of patent LAs.

RESULTS

Groups 1, 2, 3, and 4 included 124, 104, 45, and 63 patients, respectively. The median follow up duration was 65.1 months. Significant differences in the incidence of overall type II endoleak (T2EL) at discharge between Group 1 and Group 2 (59.7% vs. 36.5%, p < .001) and between Group 3 and Group 4 (33.3% vs. 4.8%, p < .001) were observed. In patients with a pre-operatively patent IMA, the rate of freedom from aneurysm sac enlargement was significantly lower in Group 1 than in Group 2 (69.0% vs. 81.7% five years after EVAR, p < .001). In patients with a pre-operatively occluded IMA, the freedom rate from aneurysm sac enlargement was not significantly different between Groups 3 and Group 4 (95.0% vs. 100% five years after EVAR, p = .075).

CONCLUSION

A high number of patent LAs seemed to have a significant role in sac enlargement with T2EL when the IMA was patent pre-operatively, whereas a high number of patent LAs seemed to have limited influence on sac enlargement when the IMA was occluded pre-operatively.

Early- and Mid-Term Results of Abdominal Endovascular Aneurysm Repair Using an Aortic Cuff Prior to the Main Body to Prevent Type II Endoleaks

PURPOSE

Postoperatively persistent type II endoleaks (T2ELs) in abdominal endovascular aneurysm repair (EVAR) are known risk factors for long-term aneurysm enlargement. Therefore, various measures have been proposed to prevent T2ELs. Notably, the Kilt technique, which can be used in patients with dumbbell-shaped morphology, employs an aortic cuff deployed in the distal seal zone before the main body. Although previous studies have successfully applied this technique for preventing T2ELs, the mid- and long-term outcomes remain unclear. This study aimed to report the early- to mid-term outcomes in cases where an aortic cuff technique was used to prevent T2ELs.

MATERIALS AND METHODS

This retrospective single-center study analyzed 9 patients (mean age, 79 years; range, 69-88 years; 8 men) with abdominal aortic aneurysms. All patients underwent EVAR using an aortic cuff to prevent T2ELs. The primary end points were technical success (successful deployment) and clinical success (no T2ELs). Secondary end points included morbidity, reintervention, and aortic remodeling during follow-up.

RESULTS

The technical success rate was 100%. There were no intraprocedural or postoperative complications. No deaths or reinterventions occurred. Postoperative computed tomography showed no endoleaks in 6 patients, while T2ELs from the lumbar artery outside the aortic cuff deployment range were noted in 3 patients. However, no T2ELs were observed in the artery in the aortic cuff deployment range in any patient. The average number of successfully occluded arteries was 4.2 (range, 2-8). All patients had follow-up >6 (mean, 18.6; range, 6-36) months. Aneurysm sac shrinkage occurred in 5 patients during the follow-up period, whereas aneurysm size was stable in 3 patients. In contrast, only 1 patient showed transient dilation of the aneurysm sac enlargement; however, this dilation remained unchanged even after 1.5 years.

CONCLUSION

The aortic cuff technique is a favorable endovascular method for preventing T2ELs in EVAR. The present study showed that a single aortic cuff could easily and reliably occlude arteries branched from the aneurysm sac.

High incidence of type 2 endoleak and low associated adverse events in the Vascular Quality Initiative linked to Medicare claims

INTRODUCTION

Type 2 endoleak (T2EL) is the most common adverse finding on postoperative surveillance after endovascular aortic aneurysm repair (EVAR). A low rate of aneurysm-related mortality with T2EL has been established. However, the optimal management strategy and the efficacy of reintervention remain controversial. This study used data from the Vascular Quality Initiative linked to Medicare claims (VQI-Medicare) to evaluate T2LE in a real-world cohort.

METHODS

This retrospective review of EVAR procedures in VQI-Medicare included patients undergoing their first EVAR procedure between 2015 and 2017. Patients with an endoleak other than T2EL on completion angiogram and those without VQI imaging follow-up were excluded. Patients without Medicare part A or part B enrollment at the time of the procedure or without 1-year complete Medicare follow-up data were also excluded. The exposure variable was T2EL, defined as any branch vessel flow detected within the first postoperative year. Outcomes of interest were mortality, reintervention, T2EL-related reintervention, post-EVAR imaging, and T2EL behavior including spontaneous resolution, aneurysm sac regression, and resolution after reintervention. The association of prophylactic branch vessel embolization (PBE) with T2EL resolution and aneurysm sac regression was also evaluated.

RESULTS

In a final cohort of 5534 patients, 1372 (24.7%) had an identified T2EL and 4162 (75.2%) did not. The median age of patients with and without T2EL was 77 and 75 years, respectively. There were no differences in mortality, imaging, reintervention, or T2EL-related reintervention at 3 years after the procedure for patients with T2EL. The aneurysm sac diameter decreased by 4 mm (range: 9-0 mm decrease) in the total cohort. Patients with inferior mesenteric artery-based T2EL had the smallest decrease in aneurysm diameter (median 1 mm decrease compared with 1.5 mm for accessory renal artery-based T2EL, 2 mm for multiple feeding vessel-based T2EL, and 4 mm for lumbar artery-based T2EL; P < .001). Spontaneous resolution occurred in 73.7% of patients (n = 809). T2ELs with evidence of multiple feeding vessels were associated with the lowest rate of spontaneous resolution (n = 51, 54.9%), compared with those with a single identified feeding vessel of inferior mesenteric artery (n = 99, 60.0%), lumbar artery (n = 655, 77.7%), or accessory renal artery (n = 31, 79.5%) (P < .001). PBE was performed in 84 patients. Patients who underwent PBE and were without detectable T2EL after EVAR had the greatest rate of sac regression at follow-up (7 mm decrease) compared with baseline.

CONCLUSIONS

T2EL after EVAR is associated with high rates of spontaneous resolution, low rates of aneurysm sac growth, and no evidence of increased early mortality or reintervention. PBE in conjunction with EVAR may be indicated in some circumstances.

The impact of completion and follow-up endoleaks on survival, reintervention, and rupture

OBJECTIVE

Endoleaks may be seen at case completion of endovascular abdominal aortic aneurysm repair (EVAR), and the presence of an endoleak may impact outcomes. However, the clinical implications of various endoleaks seen during follow-up is not well-described. Therefore, we studied the impact of endoleaks at completion and at follow-up on mid-term outcomes.

METHODS

We reviewed patients who underwent EVAR from 2003 to 2016 within the Vascular Quality Initiative-Medicare database and identified patients with endoleak at procedure completion and during follow-up, excluding those presenting with rupture. We stratified cohorts by presence of completion and follow-up endoleak subtypes. The primary outcome was 5-year survival, and secondary outcomes included 5-year freedom from reintervention and freedom from rupture. We used Kaplan-Meier estimates and log-rank tests to analyze differences in time-to-event endpoints.

RESULTS

Of 21,745 patients with completion endoleak data, 5085 (23%) had an endoleak. Compared with those without endoleak, those with type I endoleaks had lower 5-year survival (69% vs 75%; P < .001), type II endoleaks had higher survival (79%; P < .001), and types III, IV, and indeterminate were not statistically different (73%, 73%, and 75%, respectively). Freedom from reintervention for types I and III endoleaks were significantly lower than no endoleak cohort (I: 76%; P < .001; III: 72%; P < .001 vs 83%), but freedom from rupture was higher for those with type II and III endoleak (95% and 97% vs 94%; P < .001). Of 14,479 patients with detailed follow-up endoleak data, 2290 (16%) had an endoleak. Compared with those without endoleak, types I and III had significantly lower 5-year survival (I: 80%; P = .002; III: 66%; P < .001 vs 84%), but there were no differences for types II (82%) and indeterminate (77%). Those with any type of follow-up endoleak had lower 5-year freedom from reintervention (I: 70%; P < .001; II: 76%; P = .006; III: 36%; P < .001; indeterminate: 60%; P = .007 vs 84%), and lower freedom from rupture (I: 92%; P < .001; II: 91%; P = .16; III: 88%; P = .01; indeterminate: 90%; P = .11 vs 94%).

CONCLUSIONS

Compared with patients with no endoleak, those with type I completion endoleaks have lower 5-year survival and freedom from reintervention. Patients with types I and III follow-up endoleaks also have lower survival, and any endoleak at follow-up is associated with lower freedom from reintervention and freedom from rupture. These data highlight the importance of careful patient selection and close postoperative follow-up after EVAR, as the presence of endoleaks, specifically type I and III, over time portends worse outcomes.

Translumbar type II endoleak embolization with a new liquid iodinated polyvinyl alcohol polymer: Case series and review of current literature

Purpose

To describe our experience with the use of a novel iodized Polyvinyl Alcohol Polymer liquid agent (Easyx) in type II endoleak treatment with translumbar approach.

Methods

Our case series is a retrospective review of patients with type II endoleak (T2E) treated with Easyx from December 2017 to December 2020. Indication for treatment was a persistent T2E with an increasing aneurysm sac ≥5 mm on computed tomography angiography (CTA) over a 6-month interval. Technical success was defined as the embolization of the endoleak nidus with reduction or elimination of the T2E on sequent CTA evaluation. Clinical success was defined as an unchanged or decreased aneurysm sac on follow-up CTA. Secondary endpoints included the presence of artifacts in the postprocedural cross-sectional tomographic imaging and post and intraprocedural complications.

Results

Ten patients were included in our retrospective analysis. All T2E were successfully embolized. Clinical success was achieved in 9 out of 10 patients (90%). The mean follow-up was 14 3-20 months. No beam hardening artifact was observed in follow-up CT providing unaltered imaging.

Conclusion

Easyx is a novel liquid embolic agent with lava-like characteristics and unaltered visibility on subsequent CT examinations. In our initial experience, Easyx showed to have all the efficacy requisites to be an embolization agent for type II EL management. Its efficacy, however, should be evaluated in more extensive studies and eventually compared with other agents.

Role of Aggressive Aneurysm Sac Embolization Before Endovascular Abdominal Aneurysm Repair in Preventing Type II Endoleak and Sac Expansion

Background

This study aimed to evaluate the effect of aggressive embolization of side branches arising from the aneurysmal sac before endovascular aneurysm repair.

Methods

This retrospective study included 95 patients who underwent endovascular infrarenal abdominal aortic aneurysm repair at Tottori University Hospital between October 2016 and January 2021. Of these, 54 underwent standard endovascular aneurysm repair (conventional group), and 41 underwent coiling of the inferior mesenteric and lumbar arteries before undergoing endovascular aneurysm repair (embolization group). The occurrence of type II endoleak, change in aneurysmal sac diameter, and reintervention rate due to type II endoleak during follow-up were evaluated.

Results

Compared to the conventional group, the embolization group had a significantly lower incidence of type II endoleak, more frequent aneurysmal sac shrinkage, and lower aneurysmal sac growth related to type II endoleak.

Conclusion

Our results demonstrated the effectiveness of aggressive aneurysmal sac embolization before endovascular aneurysm repair to prevent type II endoleak and the consequent long-term aneurysmal sac enlargement.

Five-Year Results of the LEOPARD Trial of Commercially Available Endografts

OBJECTIVE

The LEOPARD (Looking at EVAR Outcomes by Primary Analysis of Randomized Data) trial is a randomized controlled trial (RCT) comparing the outcomes of endovascular aneurysm repair (EVAR) using commercially available devices in a real-world population.

METHODS

A prospective, randomized, multi-center trial was performed to compare the anatomically fixated (AF) AFX/AFX2 endograft system (Endologix, Irvine, CA) to endografts with proximal fixation (PF) (Cook Medical Zenith Flex, Bloomington, IN; Gore Excluder, Flagstaff, AZ; and Medtronic Endurant II, Minneapolis, MN) in patients with infrarenal abdominal aortic aneurysms (AAA). The primary endpoint was freedom from aneurysm-related complications (ARC), a composite endpoint consisting of perioperative death (≤30 days), aneurysm rupture, conversion to open surgical repair, post-operative endoleaks, endograft migration (≥10 mm), aneurysm enlargement (≥5mm), endograft limb occlusion, and the device- or aneurysm-related reintervention.

RESULTS

The study population was 455 patients enrolled at 56 US centers: 235 patients were treated with anatomically fixated devices and 220 with proximal fixation devices. The primary endpoint supported noninferiority of the AF cohort at 1 year. The 5-year freedom from aneurysm-related complications Kaplan Meier estimates were 63.8% for anatomically fixated patients and 55.5% for proximal fixation patients (p=0.10). Kaplan-Meier estimates for freedom from aneurysm-related mortality (ARM) were 98.7% and 97.0% in the anatomically fixated group and 99.5% and 98.5% in the proximal fixation group at 1 and 5 years. There was no difference in aneurysm-related mortality, all-cause mortality, rupture, secondary interventions, and Type I and Type III endoleak between the two cohorts. The Type III endoleak rate at 5-years for the AFX cohort was 1.5% and 0.0% for the comparator cohort (p=0.11). There was a lower type II endoleak rate in the AF group at 5 years (78.8% vs. 68.4%, p=0.037). There were zero open surgical conversions (0.0%) in the anatomically fixated group and four (2.0%) in the proximal fixation group .

CONCLUSION

The 5-year results from the LEOPARD study demonstrated that there was no clinically significant difference in overall aneurysm-related outcomes between patients randomized to the AFX endograft system or commercially available endografts with proximal fixation.

Pre-Emptive Embolization of the Aneurysm Sac or Aortic Side Branches in Endovascular Aneurysm Repair: Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials

BACKGROUND

To investigate outcomes of pre-emptive embolization of the aneurysm sac or aortic side branches in endovascular aneurysm repair (EVAR).

METHODS

The review was reported as per Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 with a preregistered protocol. Bibliographic sources (MEDLINE, Embase, and CENTRAL) were searched using subject headings and free text terms. Randomized controlled trials comparing EVAR with versus without embolization were included. Pooled estimates of dichotomous outcomes were calculated using odds ratio (OR) or risk difference (RD) and 95% confidence interval (CI) applying the Mantel-Haenszel method. Continuous outcomes were summarized using mean difference (MD) and 95% CI applying the inverse variance method. The certainty of evidence was appraised with the Grading of Recommendations Assessment, Development, and Evaluation framework. Version 2 of the Cochrane tool was used to assess the risk of bias. Trial sequential analysis assumed alpha = 5% and power = 80%.

RESULTS

Four randomized controlled trials were included. No significant difference was found in aneurysm-related mortality (RD 0.00, 95% CI -0.03 to 0.03), overall mortality (OR 1.85, 95% CI 0.42-8.13), aneurysm rupture (RD 0.00, 95% CI -0.03 to 0.03), type II endoleak-related reintervention (RD -0.07, 95% CI -0.21 to 0.06), procedure time (MD 20.12, 95% CI -11.54 to 51.77), or fluoroscopy time (MD 11.17, 95% CI -11.22 to 33.56). Patients with pre-emptive embolization had significantly lower odds of type II endoleak (OR 0.45, 95% CI 0.26-0.78) and sac expansion (OR 0.19, 95% CI 0.07-0.52). The risk of bias was high for all outcomes. The certainty of evidence was very low for all outcomes, except for type II endoleak, for which it was low. Trial sequential analysis showed an inconclusive result for overall mortality and type II endoleak-related reintervention but confirmed the advantage of embolization in reducing type II endoleak and sac expansion.

CONCLUSIONS

Limited, low certainty data suggest pre-emptive embolization confers no clinical benefits in EVAR.

Fibrin Glue Sac Filling for Preventing Type II Endoleak, Short-Term Outcomes of a Prospective Randomized Controlled Trial

OBJECTIVE

Type II endoleak (T2EL) worsens the long-term results of endovascular aneurysm repair (EVAR). How to prevent T2ELs remains controversial. This study aimed to evaluate the efficacy and safety of fibrin glue sac filling (FGSF) to prevent T2ELs after EVAR.

METHODS

A prospective randomized controlled trial was conducted. Patients were randomly divided into group A (standard EVAR + FGSF) and group B (standard EVAR). The follow-up plans included outpatient or telephone consultation at 1 and 3 months and computed tomography (CT) angiography at 6 months, 1 year, and once a year after EVAR.

RESULTS

A total of 64 abdominal aortic aneurysm (AAA) patients were randomized to the 2 groups. All patients were followed up for more than 6 months. The 2 groups showed similar baseline characteristics. The rate of T2ELs on immediate angiography in group A (9.6%) was significantly lower than that in group B (33.3%, p=0.033). Moreover, the sac area change was significantly reduced in group A at 6 months after EVAR (p=0.021). However, T2EL incidence was similar at the 6-month (p=0.055) and 1-year (p=0.057) follow-ups, and AAA diameter change was also similar at 1 year. There were similar operation times, radiation doses, severe adverse events (SAEs), and reinterventions between the 2 groups.

CONCLUSION

Fibrin glue sac filling could prevent short-term type II endoleaks and promote AAA shrinkage after 6 months. The FGSF procedure is swift and straightforward; however, patients are at risk of bowel ischemia, especially after previous bowel resections or concomitant superior mesenteric artery (SMA) disease.

CLINICAL IMPACT

Standard endovascular aneurysm repair (EVAR) couldn't prevent type II endoleak (T2EL). In this study, we found fibrin glue sac filling (FGSF) could prevent T2EL and promote AAA shrinkage in a short term. And the FGSF procedure is easy, it will be a useful supplement to standard EVAR for clinicians. And FGSF might have potential usefulness on ruptured aneurysms, although without direct evidence.Fibrin glue is often used to hemostasis and tissue adhesion in surgical patients and burn patients, we firstly carry out a randomized controlled study and prove that fibrin glue sac filling could prevent T2EL and promote sac remodeling.

Contrast-enhanced CT radiomics improves the prediction of abdominal aortic aneurysm progression

OBJECTIVES

To determine if three-dimensional (3D) radiomic features of contrast-enhanced CT (CECT) images improve prediction of rapid abdominal aortic aneurysm (AAA) growth.

METHODS

This longitudinal cohort study retrospectively analyzed 195 consecutive patients (mean age, 72.4 years ± 9.1) with a baseline CECT and a subsequent CT or MR at least 6 months later. 3D radiomic features were measured for 3 regions of the AAA, viz. the vessel lumen only; the intraluminal thrombus (ILT) and aortic wall only; and the entire AAA sac (lumen, ILT, and wall). Multiple machine learning (ML) models to predict rapid growth, defined as the upper tercile of observed growth (> 0.25 cm/year), were developed using data from 60% of the patients. Diagnostic accuracy was evaluated using the area under the receiver operating characteristic curve (AUC) in the remaining 40% of patients.

RESULTS

The median AAA maximum diameter was 3.9 cm (interquartile range [IQR], 3.3-4.4 cm) at baseline and 4.4 cm (IQR, 3.7-5.4 cm) at the mean follow-up time of 3.2 ± 2.4 years (range, 0.5-9 years). A logistic regression model using 7 radiomic features of the ILT and wall had the highest AUC (0.83; 95% confidence interval [CI], 0.73-0.88) in the development cohort. In the independent test cohort, this model had a statistically significantly higher AUC than a model including maximum diameter, AAA volume, and relevant clinical factors (AUC = 0.78, 95% CI, 0.67-0.87 vs AUC = 0.69, 95% CI, 0.57-0.79; p = 0.04).

CONCLUSION

A radiomics-based method focused on the ILT and wall improved prediction of rapid AAA growth from CECT imaging.

KEY POINTS

• Radiomic analysis of 195 abdominal CECT revealed that an ML-based model that included textural features of intraluminal thrombus (if present) and aortic wall improved prediction of rapid AAA progression compared to maximum diameter. • Predictive accuracy was higher when radiomic features were obtained from the thrombus and wall as opposed to the entire AAA sac (including lumen), or the lumen alone. • Logistic regression of selected radiomic features yielded similar accuracy to predict rapid AAA progression as random forests or support vector machines.

Prophylactic Perigraft Arterial Sac Embolization During EVAR: Minimizing Type II Endoleaks and Improving Sac Regression

BACKGROUND

Type II endoleaks (ELII) are the most common complication following endovascular aneurysm repair (EVAR). Persistent type II endoleaks require continual surveillance and have been shown to increase the risk of Type I and III endoleaks, sac growth, need for intervention, conversion to open or even rupture directly or indirectly. These are often difficult to treat following EVAR and there are limited data regarding the effectiveness of prophylactic treatment of ELII. The aim of this study is to report midterm outcomes of prophylactic perigraft arterial sac embolization (pPASE) performed in patients undergoing EVAR.

METHODS

This is a comparison of two elective cohorts of those undergoing EVAR using the Ovation stent graft with and without prophylactic branch vessel and sac embolization. Patients who underwent pPASE at our institution had data collected in a prospective, IRB approved database. These were compared against the core lab adjudicated data from the Ovation IDE trial. Prophylactic PASE was performed at the time of EVAR with thrombin, contrast and gelfoam if lumbar or mesenteric arteries were patent. Endpoints included freedom from ELII, reintervention, sac growth, all-cause mortality (ACM) and aneurysm-related mortality (ARM).

RESULTS

Thirty-six patients (13.1%) underwent pPASE, while 238 patients (86.9%) had standard EVAR. Median follow-up was 56 months (IQR 33-60). The 4-year freedom from ELII estimates were 84% for the pPASE vs 50.7% for the standard EVAR group (P=0.0002). All aneurysms in the pPASE group remained stable in size or demonstrated regression, whereas aneurysm sac expansion was seen in 10.9% of the standard EVAR group, P=0.03. At 4 years, mean AAA diameter decreased by 11mm (95% CI 8-15) in the pPASE group vs 5mm (95%CI 4-6) for the standard EVAR group, P=0.0005. There were no differences in the 4-year freedom from ACM and ARM. However, the difference in reintervention for ELII trended toward significance (0.0% vs 10.7%, P=0.1). On multivariable analysis, pPASE was associated with a 76% reduction in ELII [aHR(95%CI): 0.24 (0.08-0.65), P=0.005].

CONCLUSION

These results suggest that pPASE in those undergoing EVAR is safe and effective in the prevention of EII and significantly improves sac regression over standard EVAR while minimizing the need for reintervention.

Morphological and Clinical Predictors of Early/Follow-up Failure of the Endovascular Infrarenal Abdominal Aneurysm Repair With Currently Available Endografts

PURPOSE

To report outcomes of endovascular repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs) with currently-available endografts and identify predictors of technical/clinical failure.

MATERIALS AND METHODS

Patients undergoing EVAR between 2012 and 2020 were prospectively collected and retrospectively analyzed. Technical success (TS: no type I-III endoleaks, renal/hypogastric arteries loss, iliac leg occlusion, conversion to open repair and mortality within 24 postoperative hour), proximal neck-related TS (nr-TS: no proximal type I endoleaks, unplanned renal arteries coverage), and 30-day mortality were assessed as early outcomes. Proximal type I endoleak (ELIa), survival and freedom from reinterventions (FFRs) were assessed during follow-up. Uni/multivariate analysis and Cox-regression were used to identified factors associated with early and follow-up outcomes; FFR and survival were assessed by Kaplan-Meier analysis.

RESULTS

A total of 710 were included. Technical success and nr-TS were 692 (98%) and 700 (99%), respectively. The presence of ≥2 hostile anatomical infrarenal neck characteristics was associated with technical failure (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.3-4.1; p: 0.007). Infrarenal neck angle >90° (OR: 2.88; 95% CI: 9.6-50.3; p: 0.004), barrel shape (OR: 2.33; 95% CI: 11.1-100.3; p: 0.02) or presence of ≥2 hostile anatomical infrarenal neck characteristics (OR: 2.16; 95% CI: 2.5-5.3; p: 0.03) were independent risk factors for neck-related technical failures. Six (0.8%) patients died within 30 postoperative days. Chronic obstructive pulmonary disease (OR: 16; 95% CI: 1.1-218.3; p: 0.04) and urgent repair (OR: 15; 95% CI: 1.8-119.6; p: 0.01) were independent risk factors for 30-day mortality. The mean follow-up was 53±13 months. There were 12 (1.7%) ELIa during follow-up. Infrarenal neck length <15 mm (hazard ratio [HR]: 2.8; 95% CI: 1.9-9.6; p: 0.005), diameter >28 mm (HR: 2.7; 95% CI: 1.6-9.5; p: 0.006), angle ≥90° (HR: 2.7; 95% CI: 8.3-50.1; p: 0.007), and persistent type II endoleak (HR: 2.9; 95% CI: 1.6-10.1; p: 0.004) were independent risk factors for ELIa. Freedom from reintervention was 91% at 5 years. The ELIa was an independent risk factor for reinterventions during follow-up (HR: 29.5; 95% CI: 1.4-1.6; p<0.001). Survival was 74% at 5 years with 2 cases (0.3%) of late aortic-related mortality. Peripheral arterial occlusive disease (HR: 1.9; 95% CI: 1.4-3.65; p: 0.03), aneurysm diameter ≥65 mm (HR: 2.2; 95% CI: 1.4-3.26; p<0.001), and infrarenal neck length <15 mm (HR: 1.7; 95% CI: 1.2-2.35; p: 0.04) were independent risk factors for mortality during follow-up.

CONCLUSION

Endovascular repair with currently-available endografts has high TS and low 30-day mortality. Survival and FFRs were satisfactory at mid-term. Pre/postoperative risk factors for technical and clinical failure were identified and they should be considered in EVAR indication and postoperative management to reduce complications and improve mid-term outcome.

CLINICAL IMPACT

Pre and postoperative risk factors for technical and clinical EVAR failure can be identified and they should be considered in EVAR indication and postoperative management to reduce complications and improve mid-term outcome.

Routine Inferior Mesenteric Artery Embolisation is Unnecessary Before Endovascular Aneurysm Repair

OBJECTIVE

A type II endoleak is the most common complication during surveillance after endovascular aneurysm repair (EVAR), and a patent inferior mesenteric artery (IMA) is a known risk factor for an endoleak. The effect of routine IMA embolisation prior to EVAR on overall outcome is unknown. The aim of the study was to compare two strategies: routine attempted IMA embolisation prior to EVAR (strategy in centre A) and leaving the IMA untouched (strategy in centre B).

METHODS

Patients were treated with EVAR in two centres during the period 2005 - 2015, and the data were reviewed retrospectively. The primary endpoints were re-intervention rate due to type II endoleaks and the late IMA embolisation rate. Secondary endpoints included EVAR related re-intervention, sac enlargement, aneurysm rupture, and open conversion rates.

RESULTS

Strategy A was used to treat 395 patients. The IMA was patent in 268 (67.8%) patients, and embolisation was performed in 164 (41.5%). The corresponding figures for strategy B were 337 patients with 279 (82.8%) patent IMAs, two (0.6%) of which were embolised. The mean duration of follow up was 70 months for strategy A and 68.2 months for strategy B. The re-intervention rates due to a type II endoleak were 12.9% and 10.4%, respectively (p = .29), with no significant difference in the rate of re-interventions to occlude a patent IMA (2.0% and 4.7%, respectively; p = .039). The EVAR related re-intervention rate was similar, regardless of strategy (24.1% and 24.6%, respectively; p = .93). Significant sac enlargement was seen in 20.3% of cases treated with strategy A and in 19.6% treated with strategy B (p = .82). The rupture and conversion rates were 2.5% and 2.1% (p = .69) and 1.0% and 1.5% (p = .40), respectively.

CONCLUSION

The strategy of routinely embolising the IMA does not seem to yield any significant clinical benefit and should therefore be abandoned.

A Novel Technique and Outcomes for Transcaval Endoleak Embolization

BACKGROUND

Strategies for embolization of type 2 endoleaks include translumbar, transgraft, transarterial, and transcaval approaches. The transcaval approach is limited by an inconsistent ability to access the aortic sac and the risk of puncturing and damaging the endograft or adjacent structures. We describe a novel technique for caval to aortic aneurysm sac access and report early outcomes.

METHODS

A retrospective review of all patients who underwent transcaval embolization (TCE) at a tertiary referral center. From March 2019 to June 2021, 12 patients were identified to have undergone a novel approach to transcaval aortic sac access using a 0.014″ heavy weight tip wire guide and continuous current electrocautery to create the connection between the inferior vena cava and aortic aneurysm sac. The endoleak outflow vessel is then selectively embolized with coils or liquid embolic agents. When selective embolization was not possible, the aneurysm sac was instilled with liquid embolic agents to induce thrombosis.

RESULTS

Twelve patients underwent transcaval embolization using this method over the 3-year period. The average patient age was 79.2 ± 6.2 years and 10/12 (83.3%) were male. A high rate of comorbidities was noted in the cohort. Transcaval access into the aortic sac was achieved in all patients, while selective cannulation of outflow vessels was accomplished in 2/12 (16%) target vessels. Of these, both cases had vessels embolized using detachable coils and liquid embolic agents. Nonselective embolization was performed using liquid embolic and thrombotic agents in the other 10/12 cases. There was one perioperative complication of minor bleeding (1/12, 8.3%). Two patients were observed in intensive care unit for back pain. A persistent endoleak was identified on postoperative imaging performed at 30 days in 4/12 (33.3%) patients. Sac enlargement > 5 mm following TCE was observed in 3/12 (25%) patients. Three patients underwent open conversion with endovascular aneurysm repair explant. One patient was explanted at 1 month after failure to embolize the endoleak flow channel using TCE. A second was explanted for persistent endoleak found to be a Type IIIb with aortic diameter growth > 5 mm at 15-month follow-up. The third explant was performed for aortic sac infection at 4 months postprocedure without endoleak.

CONCLUSIONS

TCE is an adjunctive technique to treat endoleaks in patients who have either failed transarterial or translumbar access. An electrified 0.014″ chronic total occlusion wire technique for transcaval access to the aortic sac for endoleak embolization can be successful in all cases without significant acute morbidity or mortality. The transcaval approach is still limited by ability to steer catheters and microcatheters into the outflow vessels with a resultant persistent endoleak and eventual need for explant.

Preoperative predictive factors for type II endoleak: Trying to define high-risk patients

OBJECTIVE

Type 2 endoleaks (T2E) continue to be the "Achilles Heel" of endovascular aneurysm repair (EVAR). The aim of this study is to analyze preoperative factors of patients who underwent EVAR to define risk factors for T2E.

METHODS

From January 2015 to June 2020, 140 of 191 patients who underwent EVAR in our institution meet inclusion criteria for this study. Postoperative image control were performed using duplex ultrasound or CT scan. All T2E detected during follow-up were confirmed by angio CT. Preoperative anatomic and clinical variables were analyzed for T2E using t-test, Mann-Whitney U test and Fisher exact test. ROC curves and the corresponding area under the curve (AUC) were used to describe the predictive accuracy for endoleak.

RESULTS

T2E was detected in 16 patients (11.43%)0.12 of them (75%) were persistent and 10 (62.5%) provoked sac enlargement. Predictive factors for T2E were a greater IMA diameter (2.5 ± 0.5 vs. 3.3 ± 0.5, p < 0.001) and an increasing number of LA (4.8 ± 1.6 vs. 6.7 ± 1.4, p < 0.001). ROC curve analysis stablished thresholds of 3.5 mm for IMA diameter (sensitivity 77%, specificity 86%) and 5.5 for patent LA (sensitivity 88%, specificity 59%) as risk factor to develop T2E.

CONCLUSIONS

Preoperative aortic side branches embolization to avoid T2E is not still standarised. We tried to define a group of high-risk patients for T2E. According to our findings, patients with a preoperative IMA> 3 mm and more than 5 patent LA should be considered for pre-EVAR embolization.

Use of the triple coaxial (triaxial) microcatheter system in superselective arterial embolisation for complex interventional cases: an initial experience with the system

LEARNING OBJECTIVE

To share our experience in utilising the triple coaxial (triaxial) system in superselective cannulation of arteries for complex embolisation procedures.

BACKGROUND

Percutaneous transcatheter selective embolisation is widely performed for a myriad of oncologic (e.g., trans-arterial chemo- or radio-embolisation) and non-oncologic (e.g., for embolisation of bleeding and benign conditions such as uterine fibroid and benign prostate hyperplasia) purposes. The cornerstone of such embolisation procedures is to achieve superselective cannulation of the arterial supply to the tumour/organ, preventing the complication of non-target embolisation. However, a multitude of factors, such as complex vascular anatomy, can pose challenges to achieving this goal.

CLINICAL FINDINGS/PROCEDURAL DETAILS

The triaxial system utilises two smaller microcatheters telescoped through each other over a microwire. We have adopted the triaxial system for specific cases due to its perceived superior torquability and trackability compared to the conventional coaxial system, in which superselective cannulation is anticipated to be challenging. The triaxial system is also favourable in situations where the inner microcatheter needs to be "sacrificed" after administering the embolics (e.g., after administering radioisotopes in radioembolisation, N-butyl cyanoacrylate [NBCA] glue or ethylene-vinyl alcohol copolymer [EvOH] Onyx). Through a case series with procedural details such as fluoroscopic time, contrast administered, etc., we hope to illustrate the utility and efficacy of the triaxial system as well as present pitfalls in its usage.

CONCLUSION

The triaxial system appears to be a valuable system for certain complex embolisation procedures and could be better suited than the conventional coaxial systems in these specific circumstances.

Circulating Extracellular Vesicles: Their Role in Patients with Abdominal Aortic Aneurysm (AAA) Undergoing EndoVascular Aortic Repair (EVAR)

Abdominal aortic aneurysm (AAA) is a frequent aortic disease. If the diameter of the aorta is larger than 5 cm, an open surgical repair (OSR) or an endovascular aortic repair (EVAR) are recommended. To prevent possible complications (i.e., endoleaks), EVAR-treated patients need to be monitored for 5 years following the intervention, using computed tomography angiography (CTA). However, this radiological method involves high radiation exposure in terms of CTA/year. In such a context, the study of peripheral-blood-circulating extracellular vesicles (pbcEVs) has great potential to identify biomarkers for EVAR complications. We analyzed several phenotypes of pbcEVs using polychromatic flow cytometry in 22 patients with AAA eligible for EVAR. From each enrolled patient, peripheral blood samples were collected at AAA diagnosis, and after 1, 6, and 12 months following EVAR implantation, i.e. during the diagnostic follow-up protocol. Patients developing an endoleak displayed a significant decrease in activated-platelet-derived EVs between the baseline condition and 6 months after EVAR intervention. Furthermore, we also observed, that 1 month after EVAR implantation, patients developing an endoleak showed higher concentrations of activated-endothelial-derived EVs than patients who did not develop one, suggesting their great potential as a noninvasive and specific biomarker for early identification of EVAR complications.

Effectiveness of Inferior Mesenteric Artery Embolization on Type II Endoleak-Related Complications after Endovascular Aortic Repair (EVAR): Systematic Review and Meta-Analysis

Type II endoleak is one of the most common and problematic complications after endovascular aneurysm repair. It has been suggested that the inferior mesenteric artery (IMA) embolization could prevent further adverse events and postoperative complications. This article is a systematic review and meta-analysis following PRISMA guidelines. The Medline, PubMed, Embase, and Cochrane databases were used to identify studies that investigated the effect of IMA embolization on the occurrence of type II endoleaks and secondary interventions in a group of patients with abdominal aortic aneurysm who underwent EVAR compared with results after EVAR procedure without embolization. A random effects meta-analysis was performed. Of 3510 studies, 6 studies involving 659 patients were included. Meta-analysis of all studies showed that the rate of secondary interventions was smaller in patients with IMA embolization (OR, 0.17; SE, 0.45; 95% CI, 0.07 to 0.41; p < 0.01; I2 = 0%). The occurrence of type II endoleaks was also smaller in the embolization group (OR, 0.37; SE, 0.21; 95% CI, 0.25 to 0.57; p < 0.01; I2 = 16.20%). This meta-analysis suggests that IMA embolization correlates with lower rates of type II endoleaks and secondary interventions.

Technique of partial open surgical stent graft explantation with preservation of fenestrated stent graft component to treat recalcitrant type II endoleak

Fenestrated and branched stent grafts have been used with increasing frequency for endovascular repair of complex aortic aneurysms. Endoleaks are frequently encountered after endovascular aortic aneurysm repair, with treatment indicated when associated with an enlarging aneurysm sac. When endovascular treatment fails, complex open surgical explantation will become necessary. We have reported the technique of partial graft explantation in a patient with a recalcitrant type II endoleak. Both the proximal fenestrated segment and the distal iliac limbs were preserved, and aortic control was obtained by clamping the infrarenal stent graft. This method allowed for more distal aortic cross-clamping and negated the need for visceral branch reimplantation.

Intermittent endoleak via an aneurysm–iliac venous fistula after endovascular aneurysm repair

We have reported the rare case of an intermittent endoleak via an aneurysm–venous fistula (AVF). An 89-year-old woman had experienced postoperative sac expansion 6 years after she had undergone endovascular aneurysm repair. During aneurysmorrhaphy, we detected a small AVF, which was the source of the endoleak responsible for the aneurysmal sac expansion. This AVF had a check valve-like mechanism that allowed the inflow of blood from the iliac vein to the sac when the venous pressure exceeded the endotension. Our case has demonstrated the occurrence of an AVF after endovascular aneurysm repair that had resulted in an endoleak that was invisible on imaging studies and the presence of endotension.

Two decades of experience in explantation and graft preserving strategies following primary endovascular aneurysm repair and lessons learned

Objectives

We aim to scrutinize our evolving re-intervention strategies following primary endovascular aortic aneurysm repair (EVAR) - EVAR GORE SalvAge Fabric Technique (ARAFAT), aortic sac double breasting with endograft preservation, and stent-graft explantation.

Methods

We performed 1,555 aortic interventions over the study period, including 910 EVARs. Factors associated with the need for reintervention and the likelihood of chronic fabric fatigue failure (CFFF) were investigated. Using conventional and innovative diagnostic modalities with Prone contrASt enHanced computed tomography Angiography (PASHA), 136 endoleaks (ELs) were identified (15 type I, 98 type II; 18 type III; 5 type IV).

Results

Forty-four (4.84%) patients underwent re-intervention post-primary EVAR; 18 ARAFATs, 12 double breastings, and 14 explantations. Choice of re-intervention was based on patient fitness and mode of failure. Mean EL detection duration following primary EVAR was 53.3 ± 6.82 months, while mean time to re-intervention was 70.20 ± 6.98 months. The mean sac size before the primary EVAR and re-intervention was 6.00 ± 1.75 cm and 7.51 ± 1.94 cm, respectively. Polyester (61.40%) was the most commonly employed stent-graft material. Use of more than three modular stent-graft components (3.42 ± 1.31, p = 0.846); with the proximal stent-graft diameter of 31.6 ± 3.80 cm (p = 0.651) and the use of iliac limbs more than 17 mm (p = 0.364), all added together are contributing factors. We had one peri-operative mortality following explantation due to sepsis-induced multiorgan failure.

Conclusions

Our re-intervention strategies matured from stent graft explantation to graft preservation with endovascular relining of the stent-graft. Graft preservation with aortic sacotomy and double breasting were used to manage concealed ELs due to aortic hygroma.

Systematic review and network meta-analysis of pre-emptive embolization of the aneurysm sac side branches and aneurysm sac coil embolization to improve the outcomes of endovascular aneurysm repair

Objective

Previous reports have revealed a high incidence of type II endoleak (T2EL) after endovascular aneurysm repair (EVAR). The incidence of T2EL after EVAR is reduced by pre-emptive embolization of aneurysm sac side branches (ASSB) and aneurysm sac coil embolization (ASCE). This study aimed to investigate whether different preventive interventions for T2EL were correlated with suppression of aneurysm sac expansion and reduction of the re-intervention rate.

Methods

The PubMed, Web of Science, MEDLINE and Embase databases, and conference proceedings were searched to identify articles on EVAR with or without embolization. The study was developed in line with the Participants, Interventions, Comparisons, Outcomes, and Study design principles and was conducted and reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We used network meta-analysis based on multivariate random-effects meta-analysis to indirectly compare outcomes of different strategies for embolization during EVAR.

Results

A total of 31 studies met all inclusion criteria and were included in the qualitative and quantitative syntheses. The included studies were published between 2001 and 2022 and analyzed a total of 18,542 patients, including 1,882 patients who received prophylactic embolization treatment during EVAR (experimental group) and 16,660 who did not receive prophylactic embolization during EVAR (control group). The effect of pre-emptive embolization of the inferior mesenteric artery (IMA) (IMA-ASSB) in preventing T2EL was similar (relative risk [RR] 1.01, 95% confidence interval [CI] 0.38–2.63) to the effects of non-selective embolization of ASSB (NS-ASSB) and ASCE (RR 0.88, 95% CI 0.40–1.96). IMA-ASSB showed a better clinical effect in suppressing the aneurysm sac expansion (RR 0.27, 95% CI 0.09–2.25 compared with NS-ASSB; RR 0.93, 95% CI 0.16–5.56 compared with ASCE) and reducing the re-intervention rate (RR 0.34, 95% CI 0.08–1.53 compared with NS-ASSB; RR 0.66, 95% CI 0.19–2.22 compared with ASCE). All prophylactic embolization strategies improved the clinical outcomes of EVAR.

Conclusion

Prophylactic embolization during EVAR effectively prevents T2EL, suppresses the aneurysm sac expansion, and reduces the re-intervention rate. IMA embolization demonstrated benefits in achieving long-term aneurysm sac stability and lowering the risk of secondary surgery. NS-ASSB more effectively reduces the incidence of T2EL, while IMA embolization alone or in combination with ASCE enhances the clinical benefits of EVAR. In addition, as network meta-analysis is still an indirect method based on a refinement of existing data, more studies and evidence are still needed in the future to establish more credible conclusions.

Applying patient characteristics, stent-graft selection, and pre-operative computed tomographic angiography data to a machine learning algorithm: Is endoleak prediction possible?

INTRODUCTION

This study aims to predict endoleak after endovascular aneurysm repair (EVAR) using machine learning (ML) integration of patient characteristics, stent-graft configuration, and a selection of vessel lengths, diameters and angles measured using pre-operative computed tomography angiography (CTA).

METHODS

We evaluated 1-year follow-up CT scans (arterial and delayed phases) in patients who underwent EVAR for the presence or absence of an endoleak. We also obtained data on the patient characteristics, stent-graft selection, and preoperative CT vessel morphology (diameter, length, and angle). The extreme gradient boosting (XGBoost) for the ML system was trained on 30 patients with endoleaks and 81 patients without. We evaluated 5217 items in 111 patients with abdominal aortic aneurysms, including the patient characteristics, stent-graft configuration and vascular morphology acquired using pre-EVAR abdominal CTA. We calculated the area under the curve (AUC) of our receiver operating characteristic analysis using the ML method.

RESULTS

The AUC, accuracy, 95% confidence interval (CI), sensitivity, and specificity were 0.88, 0.88, 0.79-0.97, 0.85, and 0.91 for ML applying XGBoost, respectively.

CONCLUSIONS

The diagnostic performance of the ML method was useful when factors such as the patient characteristics, stent-graft configuration and vessel length, diameter and angle of the vessels were considered from pre-EVAR CTA.

IMPLICATIONS FOR PRACTICE

Based on our findings, we suggest that this is a potential application of ML for the interpretation of abdominal CTA scans in patients with abdominal aortic aneurysms scheduled for EVAR.

Persisting Type 2 Endoleaks Following EVAR for AAA Are Associated With AAA Expansion

PURPOSE

To determine the evolution of abdominal aortic aneurysm (AAA) diameter in the presence of persisting type 2 endoleaks (pEL2) following endovascular abdominal aortic aneurysm repair (EVAR).

MATERIALS AND METHODS

This is a retrospective, single-center, case-control study. All patients with pEL2 (pEL2 group, persisting for > 12 months) between 2004 and 2018 were identified and compared with a 1:1 age- and gender-matched control with no endoleak (control group). Primary outcome measures were freedom from AAA expansion and freedom from AAA shrinkage over time. AAA diameter measurements were performed on computed tomography angiography (CTA). Secondary outcome measures were survival, AAA-related mortality, reinterventions for pEL2, incidence of secondary type 1 endoleaks (EL1), and infrarenal aortic branch vessel anatomy.

RESULTS

A total of 773 patients were treated with EVAR for AAA between 2004 and 2018. Of them, 286 patients demonstrated type 2 endoleaks (EL2) in postoperative CTA or intraoperative angiography (37%). Forty-five of 286 EL2 (15.7%) were pEL2 (pEL2 group). Freedom from AAA expansion in the pEL2 group was 100%, 96.7%, 85.2%, and 54.3% after 1, 2, 3, and 4 years, respectively, compared with 100% after 1, 2, 3, and 4 years in the control group (p<0.01). Freedom from AAA shrinkage in the pEL2 group after 1, 2, 3, and 4 years was 95.5%, 90.4%, 90.4%, and 79.1%, respectively, compared with 86.7%, 34.8%, 19.3%, and 19.3% in the control group (p<0.01). Overall survival at 1, 2, 3, and 4 years was 100%, 97.6%, 95.0% and 95.0% in the pEL2 group and 100% at 1, 2, 3, and 4 years in the control group (p=0.17). There were no AAA-related deaths in either group. Patients with pEL2 had a significantly increased number of infrarenal aortic branches (p<0.05, respectively). Eighteen patients (40.0%) in the pEL2 group underwent 34 reinterventions for pEL2, with a median follow-up (FU) of 925 days (0-4173). Clinical success was achieved in 9 patients (50.0%). Four patients (8.9%) with pEL2 developed secondary EL1 after a median FU of 1278 days (662-2121).

CONCLUSION

pEL2 are associated with AAA expansion during midterm FU. Further studies are warranted to evaluate the association of AAA expansion due to pEL2 with clinical outcomes to allow recommendations with regard to treatment indications.

Inferior Mesenteric Artery Associated Type II Endoleaks: Are They Predictable?

Purpose: This study aims to evaluate the relationship between inferior mesenteric artery (IMA) diameter and risk of type II endoleak.

Subjects and Methods: A retrospective study design to review all EVARs performed over a 4-year period at a tertiary care center. Out of the total cohort of 400 patients who underwent EVAR, 41 patients (10.3%) developed type II endoleak. The mean IMA ostial diameter for patients with type II endoleak secondary to IMA contributories was 4mm, while the mean IMA diameter for patients with lumbar arteries contributing to the type II endoleak was 3.7mm.

Results: Statistical analysis using a paired t-test did not show a statistically significant difference in the IMA ostial diameter between the two groups.

Conclusion: There is no significant correlation between preprocedural IMA ostium diameter and type II endoleak development and hence, preprocedural IMA embolization is not an appropriate prophylactic management strategy.

Significance of preoperative thrombus burden in the prediction of persistent Type II endoleak and re-intervention following infra-renal EVAR

BACKGROUND

Persistent Type II endoleak has necessitated prolonged surveillance and is a reason for re-intervention following infra-renal endovascular aneurysm repair (EVAR). The aim of this study was to assess the association of thrombus burden (TB) within the aneurysmal sac in the prediction of persistent Type II endoleaks.

METHODS

Consecutive patients undergoing infra-renal EVAR from October 2009 to October 2017 in a single vascular network were included. TB was assessed on preoperative CT-angiogram and was defined as a percentage of thrombus across the maximal sac diameter in comparison to the luminal diameter measured orthogonally at the same level. Patients were categorised into 3 groups; Low TB (<25%), Medium TB (25%-50%) and High TB (>50%). All patients underwent postoperative EVAR surveillance comprising of computed tomographic angiography or duplex ultrasound. Type II endoleak observed for more than one year was defined as persistent Type II endoleak. Odds ratio and Student's T-test were used to determine significance.

RESULTS

Some 275 EVARs were performed in the study period. 45 procedures were excluded due to either iliac-only intervention (n=9), no pre-operative information (n=7), abandoned (n=1) or less than 1 year's follow-up data (n=28). For the 230 procedures included, the median follow-up was 43 (12-102) months. There were no significant differences between the groups for age, gender, co-morbidities nor preoperative sac diameter. There was high inter-observer reliability with a kappa value of 0.89 (0.84-0.94) with a total discordance of 7% across the cohorts. Persistent Type II endoleak occurred significantly more frequently with reduced TB: 41% of the low TB cohort compared with 4% of the high TB cohort [OR 15.36 (3.5-67.3) p=0.0003]. Re-intervention was also significantly more likely to occur in the presence of a persistent Type II endoleak compared to its absence; n=12/13 (92%) patients who underwent re-intervention had a persistent Type II endoleak [OR 43.4 (5.5-242) p=0.0003]. Sac size reduction was significantly greater in medium TB and high TB cohorts when compared to low TB; -25% and -27% vs. -15% (p=0.0046 and p<0.0001). Decreased TB was associated with a significant increase in Inferior Mesenteric Artery (IMA) patency; the mean TB, where the IMA was patent, being 29% compared to 40% where the IMA was occluded p<0.0001. When considered together, patients with a low TB and a patent IMA were even more likely to have a persistent Type II endoleak when compared to those with a high TB and an occluded IMA; [OR 34.1 (1.99-583) p=0.015].

CONCLUSION

Low thrombus burden is associated with increased rates of persistent Type II endoleak, especially in the presence of a patent IMA. High thrombus burden is associated with increased sac regression and low re-intervention rates. Thrombus burden can be assessed reliably and could be used for risk stratification in the planning of infra-renal EVAR. Pre-emptive embolization of IMA or lumbar vessels in those with low thrombus burden may be beneficial. Thrombus burden could be a useful tool for designing post-EVAR surveillance regimen.

Prophylactic Sac Outflow Vessel Embolization is Associated with Improved Sac Regression in Patients Undergoing Endovascular Aortic Aneurysm Repair

OBJECTIVE

Type II endoleaks (T2E), commonly identified after endovascular aneurysm repair (EVAR), have been associated with late endograft failure and secondary rupture. Number and size of patent aortic aneurysm sac outflow vessels, namely the inferior mesenteric, lumbar, and accessory renal arteries, have been implicated as known risk factors for persistent T2E. Given technical challenges associated with post-EVAR embolization, prophylactic embolization of aortic aneurysm sac outflow vessels has been advocated to prevent T2E; however, current evidence is limited. We sought to examine the effect of concomitant prophylactic aortic aneurysm sac outflow vessels embolization in patients undergoing EVAR.

METHODS

Patients 18 and older in the SVS Vascular Quality Initiative database who underwent elective EVAR for intact aneurysms between January 2009 and November 2020 were included. Patients with history of prior aortic repair and those without available follow-up data were excluded. Patient demographics, operative characteristics, and outcomes were analyzed by group: EVAR with or without prophylactic sac outflow vessel embolization (emboEVAR). Outcomes of interest were rates of in-hospital postoperative complications, incidence of aneurysmal sac regression (≥5mm) and T2E, and rates of re-intervention in follow-up.

RESULTS

15060 patients were included: 272 had emboEVAR and 14788 had EVAR alone. There was no significant difference between groups in terms of age, comorbidities, or anatomic characteristics including mean maximum preoperative aortic diameter (5.5 vs. 5.6 cm, p=0.48). emboEVAR was associated with significantly longer procedural times (148 vs. 124 minutes, p<0.0001), prolonged fluoroscopy (32 vs. 23 minutes, p<0.0001), increased contrast use (105 vs. 91 mL, p<0.0001), without significant reduction in T2E at case completion (17.7% vs. 16.3%, p=0.54). Incidence of postoperative complications (3.7% vs. 4.6%, p=0.56), index hospitalization reintervention rates (0.7% vs. 1.3%, p=0.59), length of stay (1.8 vs. 2 days, p=0.75), and thirty-day mortality (0% vs. 0%, p=1) were similar between groups. In mid-term follow-up (14.6±6.2 months), the emboEVAR group had a significantly greater mean reduction in maximum aortic diameter (0.69 vs. 0.54 cm, p=0.006) with a higher proportion experiencing sac regression ≥5 mm (53.5% vs. 48.7%). Re-intervention rates were similar between groups. On multivariable analysis, prophylactic aortic aneurysm sac outflow vessel embolization (OR 1.34, CI 1.04-1.74, p=0.024) was a significant independent predictor of sac regression.

CONCLUSIONS

Prophylactic sac outflow vessel embolization can be performed safely for patients with intact aortic aneurysms undergoing elective EVAR without significant associated perioperative morbidity or mortality. emboEVAR is associated with significant sac regression compared to EVAR alone in mid-term follow-up. Although there was not a decrease in the incidence of T2E, this technique shows promise and future efforts should focus on identifying a subset of aneurysm and outflow branch characteristics that will benefit from concomitant selective versus complete prophylactic sac outflow vessel embolization.

Effects of antithrombotic therapy on abdominal aortic aneurysm sac size after endovascular repair in patients with favorable neck anatomy

PURPOSE

To evaluate the influence of antiplatelet or anticoagulant therapy on sac behavior after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) MATERIALS AND METHODS: This study retrospectively analyzed data from patients with favorable neck anatomy who underwent EVAR between 2007 and 2019. Patients with ruptured AAA and ≤1 year of sac behavior evaluation were excluded. Sac shrinkage after 1 year, persistent type II endoleak, and late sac expansion were examined.

RESULTS

In total, 182 patients with favorable neck anatomy were included in this study. Multivariable analysis identified occluded inferior mesenteric artery (IMA [P = .049]), presence of posterior thrombus (P = .009) and no antiplatelet therapy (P = .012) as factors positively associated with sac shrinkage at 1 year. Persistent type II endoleak was detected in 56 (30.8%) patients, with patent IMA (P = .006), lack of posterior thrombus (P = .004), number of patent lumbar arteries (P = .004), and antiplatelet therapy (P = .039) being identified as significant risk factors. Multivariable analysis identified larger initial AAA diameter (P < .001), lack of posterior thrombus (P = .038), and antiplatelet (P = .038) and anticoagulation therapies (P = .003) as risk factors for late sac expansion.

CONCLUSIONS

After EVAR in patients with favorable neck anatomy, antiplatelet therapy is associated with lack of sac regression at 1 year, whereas antiplatelet and anticoagulant therapies are risk factors for late sac expansion.

The Distance From the Primary Intimal Tear to the Left Subclavian Artery Predicts Thoracic Aortic Enlargement After Thoracic Endovascular Aortic Repair of Type B Aortic Dissection: A Retrospective Cohort Study

PURPOSE

The purpose of this study was to evaluate the association between the distance from the primary intimal tear (PIT) to the left subclavian artery (LSA) (PIT-LSA distance) and the risk of aortic enlargement after thoracic endovascular aortic repair (TEVAR).

METHODS

This is a retrospective cohort study. A total of 228 patients were reviewed from the database of the Registry Of type B aortic dissection with the Utility of STent graft (ROBUST) study performed from January 1, 2011, to December 31, 2016. Of them, 196 patients were eligible for analysis. The PIT-LSA distance was defined as the length from the distal edge of the LSA orifice to the proximal edge of the PIT along the centerline of the true lumen. According to the border between zone 3 and zone 4 of the Ishimaru classification, patients were divided into group A (n = 117, PIT-LSA distance ≤ 2 cm) and group B (n = 79, PIT-LSA distance > 2 cm). Thoracic aortic enlargement (TAE) was defined as a thoracic aortic volume increase of ≥20%. Multivariate Cox regression was used to estimate the association between the PIT-LSA distance and risk of TAE after TEVAR.

RESULTS

The mean age was 52.3 ± 11.6 years, and 88.8% of patients were male. There were no significant differences between groups in demographic and baseline characteristics. The PIT-LSA distance was 1.1 cm (range, -1.6 to 2.0 cm) in group A, and 2.9 cm (range, 2.1-12.6 cm) in group B. TAE occurred in 27 patients in group A, and 6 in group B. The mean follow-up was 12.4 months (range, 0.10-83.1 months) in group A, and 12.63 months (range, 0.10-82.77 months) in group B. The cumulative 12- and 24-month rates of freedom from TAE were 79.0% and 71.3% in group A, versus 92.5% and 92.5% in group B, respectively. Multivariate Cox regression analysis revealed that the PIT-LSA distance was an independent predictor of TAE after TEVAR (adjusted hazard ratio, 0.66; 95% confidence interval, 0.48-0.90; p = 0.009).

CONCLUSION

Patients with a more proximal PIT location have a higher incidence of thoracic aortic enlargement after TEVAR. The location of the PIT in relation to the LSA can be used to identify patients who need closed surveillance after TEVAR or early preemptive intervention.

A systematic review of the current status of interventions for type II endoleak after EVAR for abdominal aortic aneurysms

OBJECTIVE

To study the mid- and long-term outcomes of type II endoleak treatment after EVAR and the technical aspects of different techniques to exclude endoleaks which different embolic agents.

METHODS

A systematic review was performed using the approach recommended by the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for meta-analyses of interventional studies. The comprehensive search was conducted using the following database: MEDLINE, EMBASE, and the Cochrane Library. Patient characteristic, intervention approaches, embolic agents, and results at mid and long term follow up were studied.

RESULTS

A total of 6 studies corresponding to a total of 141 patients fulfilled the inclusion criteria with a mean age of 73-78.6 years and a mean duration of follow up varying from 25 to 42 months. There were different techniques for embolization used (translumbar, transarterial, and transcaval approach) with various types of embolic agents. In all studies, the indication for embolization of the type II endoleaks was sac enlargement of more than 5 mm. A wide range of technical success rate was reported regardless of the intervention strategy being used (17,6%-100%). The overall technical success rate of all studies was 62%.

CONCLUSION

This systematic review shows that there is a wide variety of techniques to exclude a persistent type II endoleak. Different kinds of embolic agents have be used. Due to a lack of peer reviewed data on longterm follow-up, it was not possible to come to recommendations what treatment would be the best for a durable exclusion of a persistent type II endoleak after an initially successful EVAR. There remains an urgent need for proper executed studies, either randomized or with close observation in relation to longer follow-up.

[The Prophylaxis of Type 2 Endoleaks is Relevant for Long Term Success of EVAR]

One out of 8 patients needs a reintervention after EVAR during the first 5 years. Two thirds of secondary interventions aim at treating endoleaks. The prevalence of complications doubles in the presence of endoleaks. Fourth generation stent grafts do not lead to a decrease in Type 2-associated reinterventions, but to better prevention of Type 1 and 3 endoleaks. Pretreatment of potential type 2 feeding arteries with embolising agents and treatment of the occurrence of type 2 endoleaks.

Predictors of sac regression after fenestrated endovascular aneurysm repair

OBJECTIVE

Aneurysm sac regression after standard endovascular aortic repair is associated with improved outcomes, but similar data are limited after fenestrated endovascular aortic repair (FEVAR). We sought to evaluate sac regression after FEVAR, and identify any predictors of this favorable outcome.

METHODS

Patients undergoing elective FEVAR using the commercially available Zenith Fenestrated device (ZFEN; Cook Medical, Bloomington, IN) from 2012 to 2018 at a single institution were reviewed retrospectively. The maximal aortic diameter was compared between the preoperative scan and those obtained in follow-up. Patients with of 5 mm or more sac regression were included in the regression (REG) group, with all others in the nonregression (NONREG) group. Outcomes were compared between groups using univariate analysis, and logistic regression analysis was performed to identify any predictive factors for sac regression.

RESULTS

We included 132 patients undergoing FEVAR in the analysis. At a mean follow-up of 33.1 months, 65 patients (49.2%) had sac regression of 5 mm or more and comprised the REG group (n = 65 [49.2%]). The REG group had smaller diameter devices, and were less likely to have had concomitant chimney grafts placed (P < .05). The NONREG group had a higher incidence of type II endoleak (35.8% vs 12.3%; P = .002). Sac regression was associated with a significant mortality benefit on Kaplan-Meier analysis (log rank P = .02). Multivariate analysis identified adjunctive parallel grafting (odds ratio [OR], 0.01; 95% confidence interval [CI], 0.03-0.36; P < .01), persistent type II endoleak (OR, 0.13; 95% CI, 0.02-0.74; P < .01), and a greater number of target vessels (OR, 0.25; 95% CI, 0.10-0.62; P = .002) as independent predictors of failure to regress.

CONCLUSIONS

Sac regression after FEVAR occurred in nearly one-half of patients, but seems to be less common in patients with persistent type II endoleaks and those undergoing concomitant parallel grafting. Sac regression was associated with a significant survival advantage, and can be used as a clinical marker for success after FEVAR.

Effectiveness of collateral arteries embolization before endovascular aneurysm repair to prevent type II endoleaks: A systematic review and meta-analysis

OBJECTIVES

This study aimed to evaluate the effect of preventive collateral arteries embolization before endovascular aneurysm repair (EVAR) to reduce type II endoleaks (T2EL), aneurysm enlargement, and re-interventions.

METHODS

A comprehensive search of PubMed, MEDLINE, Web of Science, and Embase was conducted to identify articles in English, related to preventive collateral arteries embolization before EVAR, published until October 2020.

RESULTS

A total of 12 relevant studies, including 11 retrospective studies and one randomized controlled trial, were identified and fulfilled the specified inclusion criteria. A total of 1706 patients in 11 studies were involved in the meta-analysis. The overall incidence of T2EL was 17.3% in the embolization group vs. 34.5% in the control group (OR 0.36, p < 0.01). The incidence of persistent T2EL was 15.3% vs. 30.0% (OR 0.37, p < 0.01). Five studies reported the incidence of sac enlargement, with the rate 10.2% vs. 24.9% (OR 0.25, p < 0.01). Nine studies reported T2EL related re-interventions, and it was 1.3% in the embolization group and 10.4% in control (OR 0.14, p < 0.01). The technical success of collateral arteries embolization was 92.1% (455/494) in the 12 studies. 1.2% (10/829) patients suffered a mild complication of collateral arteries embolization, and 2/829 patients died because of the embolization.

CONCLUSION

Collateral arteries embolization is a promising measure to prevent the occurrence of T2EL, sac enlargement, and re-intervention. High-quality studies need to be conducted to provide stronger evidence-based medical suggestions about the embolize operation.