Aortic side branch embolization before endovascular aneurysm repair: incidence of type II endoleak

An updated systematic review and meta-analysis of pre-emptive aortic side branch embolization to prevent type II endoleaks after EVAR

OBJECTIVE

Pre-emptive embolization of aortic side branches may be effective in preventing type II endoleaks (T2EL) based on a previous systematic review and meta-analysis by our group. Data up to 2019 was, however, only based on retrospective studies. The aim of the current study was to update the meta-analysis and evaluate the current evidence on this treatment strategy.

METHODS

A systematic literature search was performed with the same keywords and strategies used in the previous study. The complementary search included all articles published from January 1, 2019, through May 29, 2022. The incidence of aneurysm sac growth was the primary outcome of interest.

RESULTS

Four new studies were identified, including one randomized controlled study and one nationwide registry-based retrospective study. Overall, the incidence of sac size enlargement was 4.3% in the embolization group compared with 6.8% in the control group (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.26-0.55), the incidence of T2EL was 19.7% vs 37.4% (OR, 0.38; 95% CI, 0.30-0.47), and the incidence of reintervention for T2EL was 1.2% vs 11.2% (OR, 0.12; 95% CI, 0.06-0.23).

CONCLUSIONS

Current evidence confirms lower incidence of aneurysm sac growth, T2EL, and reinterventions when pre-emptive embolization of aortic side branches is performed in conjunction with endovascular aneurysm repair, compared with no embolization. However, a higher level of evidence is still required to support a broad change of practice, including data on cost-effectiveness and on the potential effect on rupture.

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.

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.

Midterm Outcomes of Endovascular Abdominal Aortic Aneurysm Repair with Prevention of type 2 Endoleak by Intraoperative Aortic Side Branch Coil Embolization

OBJECTIVE

The midterm results of endovascular abdominal aortic aneurysm repair (EVAR) with aortic side branch coil embolization during EVAR was evaluated.

METHODS

Our center began coil embolization for all patent inferior mesenteric artery (IMA) and lumbar artery (LA) with an inner diameter more than 2.0 mm during EVAR since June 2015. When four or more LA were patent, coil embolization for LA with inner diameter 2.0 mm or less was done. EVAR without aortic side branches coil embolization was performed for 59 patients prior to June 2015 (control group) and 79 patients underwent EVAR with coil embolization during EVAR (coil group). The success rate of coil embolization for IMA and LA was evaluated in coil group. The frequency of type 2 endoleak (T2EL), freedom from aneurysm sac expansion (5 mm or more) rate and the rate of the aneurysm sac shrinkage (10 mm or more) were compared between the coil and control groups. Additionally, multiple logistic regression analysis for all patients was conducted to analyze whether IMA patency and the number of patent lumbar artery at the end of EVAR were the risk factors of the aneurysm sac expansion of 5 mm or more.

RESULTS

The success rate of IMA coil embolization was 96.4% and that of LA was 74.5%. Compared to the control group, the frequency of T2EL was significantly lower in coil group at 7 days (1.3% vs. 60.4%, P <0.0001) and at 6 months (2.1% vs 38.2%, P <0.0001) after EVAR. The freedom from aneurysm sac expansion rate was significantly better in the coil group at 5 years (100% in coil group and 65.2% in control group, P = 0.002). The rate of aneurysm sac shrinkage was significantly better in coil group (15.5% vs. 2.0% at 1 year, 42.8% vs. 6.3% at 2 years and 53.4% vs. 17.8% at 3 years, p = 0.0007). The risk of aneurysm sac expansion of 5 mm or more was estimated to be 11 times greater when the IMA was patent, and 4.9 times greater when 3 or more LAs were patent at the end of EVAR.

CONCLUSION

When IMA was occluded and the number of patent LA became 2 or less by aortic side branch coil embolization during EVAR, favorable mid-term results were safely obtained and good long-term result could be expected with EVAR.

Short-Term Re-intervention of Endovascular Abdominal Aortic Aneurysm Repair

Background and aim

Endovascular aneurysm repair (EVAR) has revolutionized the management of abdominal aortic aneurysm (AAA). The re-intervention rate following EVAR has been a subject of debate in many studies. The study aims to evaluate the short-term outcomes in terms of the early (four-year) re-intervention rate following EVAR at our centre and compare it to the average re-intervention rate of the main studies assessed by the National Institute of Health and Care Excellence (NICE).

Methods

The EVAR procedures performed over two years (2015 and 2016) were retrieved using the operation codes. The clinical portal and PACS systems were used to review the discharge summaries, clinic and multidisciplinary team (MDT) letters, as well as the scans and interventional radiology procedures to assess the patients’ adherence to follow-up and identify any re-intervention procedure done to correct underlying problems related to the EVAR performed. Patients who switched their follow-up to another hospital were contacted and interviewed about any re-intervention undergone. 

Results

A total of 108 patients underwent EVAR during the two-year study period. Twenty EVAR-related re-interventions (18.5%) were recorded, irrespective of the cause or the type of intervention. This is slightly higher than the average rate by NICE (16.89%). Type 1 endoleak represented the leading cause for re-intervention (30%). Most of the cases of re-intervention were done endovascularly (60%). Forty-five percent of the patients had a re-intervention during the first year and 35% in the third year.

Conclusion

This study shows that although our re-intervention rate following EVAR was slightly higher than the international average, EVAR is still a safe method for the repair of AAA with relatively low peri-operative morbidity and mortality. However, long-term follow-up of these patients is mandatory as re-interventions are frequently required. Nonetheless, the majority of re-interventions can be done with minimal morbidity to the patient.

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.

Feasibility and Safety of Sac Embolization Using N-Butyl Cyanoacrylate in Emergency Endovascular Aneurysm Repair for Ruptured Abdominal Aortic Aneurysms or Isolated Iliac Artery Aneurysms

PURPOSE

To evaluate the feasibility and safety of sac embolization with N-butyl cyanoacrylate (NBCA) in emergency endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (AAA) and iliac artery aneurysm (IAA) in comparison to EVAR without sac embolization.

MATERIALS AND METHODS

Between February 2012 and December 2019, among 44 consecutive patients with ruptured AAA or IAA, 29 underwent EVAR. Of these, 22 patients (median age 77.5 years; 18 men) had concomitant sac embolization using NBCA; the remaining 7 patients (median age 88 years; 6 men) underwent EVAR without sac embolization and form the control group. The technical success, clinical success (hemodynamic stabilization), procedure-related complications, and mortality were compared between the groups.

RESULTS

All EVAR procedures and embolizations were successful. The clinical success rates in the NBCA and control groups were 95% (21/22) and 71% (5/7), respectively (p=0.14). There was no complication related to the procedure. Type II endoleak occurred in 4 of 21 patients (19%) in the NBCA group vs none of the control patients. One patient (5%) died in the NBCA group vs 3 (43%) in the controls (p=0.034).

CONCLUSION

Sac embolization using NBCA in emergency EVAR appears to be feasible and safe for ruptured AAA and IAA.

Endovascular Aortic Aneurysm Repair without Type 2 Endoleak Using Concomitant N-Butyl-2-Cyanoacrylate Injection into the Abdominal Aortic Aneurysm Sac

BACKGROUND

The aim of this study was to evaluate our new method to occlude target lumber arteries using N-butyl-2-cyanoacrylate (NBCA) during endovascular aneurysm repair (EVAR) for prevention of type 2 endoleak (T2E).

METHODS AND RESULTS

Between 2013 and 2018, 176 patients who underwent EVAR for abdominal aortic aneurysm (AAA) were reviewed. Starting from October 2015, 83 patients (treatment group) underwent NBCA injection into the aneurysmal sac during EVAR. The incidence of T2E at 7 days and AAA sac diameter 12 months after EVAR were compared with those of the control group comprising 93 consecutive patients who underwent EVAR alone before 2015. The incidence of T2E at 7 days was significantly lower in the treatment group (2.4%) than in the control group (22.6%) (P < 0.001). AAA sac diameter at 12 months in the treatment group had a mean decrease of 6.6 mm as compared with the mean 4.4 mm in the control group (P = 0.026). In multivariate analysis, NBCA injection was significantly related to the reduction of incidence of T2E at 7 days (odds ratio = 11.8, P < 0.001) and a decrease in AAA sac diameter at 12 months (P < 0.001). There was no NBCA injection-related complication and reintervention in the treatment group.

CONCLUSIONS

NBCA injection might be safe and useful to reduce the incidence of T2Es and to prevent AAA sac expansion.

2D-shear wave elastography in the prediction of type II endoleaks after endovascular aneurysm repair

PURPOSE

To evaluate the usefulness of 2D-shear wave elastography (2D-SWE) in the prediction of type II endoleaks after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA).

MATERIAL AND METHODS

Twenty-nine patients underwent EVAR for AAA, and 2D-SWE was performed after EVAR. Follow-up contrast-enhanced CT and ultrasonography were performed to evaluate endoleaks in all patients. The median follow-up period was 12 months (range, 3-12 months). Patients were divided into two groups: one with an endoleak (endoleak group) and another without it (control group). We compared the elasticity index (EI) of intraluminal thrombus (ITL) and fresh thrombus (FT) between the two groups.

RESULTS

Type II endoleaks were confirmed in five of the 29 patients (endoleak group), and there were no endoleaks in the other 24 (control group). ILT was observed in 21 patients of the control group and in all patients of the endoleak group. There was a difference only in EI of ILT; the mean EI (± standard deviation) of ILT was 89 ± 16 kPA in the control group and 113 ± 25 kPA in the endoleak group (p=.037).

CONCLUSIONS

High EI of ILT may predict the occurrence of type II endoleaks after EVAR of AAA.

Velocities of type II endoleaks on Doppler ultrasonography predict outcome

OBJECTIVE

We sought to determine whether flow velocities measured using Doppler ultrasonography after endovascular aortic aneurysm repair (EVAR) can predict for resolution of type II endoleaks without intervention. We also assessed the relationship of the flow velocities to sac growth and the need for intervention. We hypothesized that hemodynamic properties suggesting low flow velocity would predict for resolution of type II endoleaks.

METHODS

The data from 23 patients with type II endoleaks identified on Doppler ultrasonography after EVAR from January 2014 to December 2017 were retrospectively analyzed. The 23 patients with type II endoleaks were split into two groups. Group 1 included the 13 patients with resolved endoleaks or shrinking sac size and group 2, the 10 patients with an increasing sac size or those requiring intervention to seal the endoleak because of an increased sac size. We analyzed the velocities of the endoleak nidus.

RESULTS

Doppler ultrasound velocities were significantly lower in patients with resolved type II endoleaks and those with a shrinking aneurysm sac size compared with those demonstrating an increase in aneurysm sac size (42.6 ± 25.2 cm/s vs 219.5 ± 84.1 cm/s; P < .0001). Of the 10 patients in group 2, nine had required intervention with either translumbar embolization or transarterial embolization, with only two experiencing complete resolution of the type II endoleak, despite the intervention. All patients in group 2 had had ≥1 duplex ultrasound scan with endoleak nidus velocities >100 cm/s. In contrast, no patient in group 1 had had any duplex ultrasound scan with endoleak nidus velocities >100 cm/s.

CONCLUSIONS

The Doppler ultrasound velocities of type II endoleaks might be able to predict for spontaneous resolution of type II endoleaks or increased sac growth. Type II endoleaks on Doppler ultrasonography with endoleak nidus velocities >100 cm/s can persistent, even with attempted treatment.

Effectiveness of Embolization of Inferior Mesenteric Artery to Prevent Type II Endoleak Following Endovascular Aneurysm Repair: A Review of the Literature

Type II endoleak is a common complication that develops after endovascular aneurysm repair. Patients with type II endoleak, which has persisted for 6 months, have a significantly higher rate of aneurysmal sac enlargement, reintervention, and rupture. To date, several studies have examined the effectiveness of preoperative embolization of branch vessels for the prevention of type II endoleak. Particularly, the embolization of the large inferior mesenteric artery (IMA) seems to be a precise, safe, and effective method. IMA is a significant risk factor for type II endoleak. However, there is currently no strong evidence to prove which patients would benefit from preventive IMA embolization. In addition, considering the incidence of type II endoleak and the adverse event rate, routine embolization seems to be unreliable and time-consuming. Moreover, previous reports of preoperative IMA embolization were retrospective. Thus, prospective and randomized studies are necessary so that the usefulness of IMA embolization can be proved and the potential benefits can be assessed. To establish preventive IMA embolization as one of the effective therapeutic strategies to prevent type II endoleak and to maximize its therapeutic effect, we should provide a wide range of therapeutic strategies to suit the state of the patient.

Preoperative Inferior Mesenteric Artery Embolization: A Valid Method to Reduce the Rate of Type II Endoleak after EVAR?

BACKGROUND

Type II endoleak is the most commonly encountered endoleak after endovascular abdominal aortic aneurysm repair (EVAR). Some have advocated preoperative inferior mesenteric artery (IMA) embolization as a valid method for reducing the incidence of this endoleak, but controversies exist. We sought to demonstrate the impact of IMA embolization using a meta-analysis of currently available studies combined with our own experience.

METHODS

We conducted an institutional review board-approved, retrospective analysis of all patients undergoing IMA embolization before EVAR between the years 2010 and 2015 and used as a control a similar group of patients with patent IMA. We divided patients from our own experience and 5 other studies into 2 groups: those who did not undergo IMA embolization (control) before EVAR and those who did. Rates of type II endoleaks, aneurysm sac regression, and secondary interventions were analyzed.

RESULTS

A total of 620 patients from 6 studies were analyzed, including 258 patients who underwent an attempted IMA embolization before EVAR with a cumulative success rate of 99.2% (range, 93.8% to 100%). There was 1 fatality associated with IMA embolization. A meta-analysis showed that preoperative IMA embolization protected against type II endoleaks compared to the control group (odds ratio [OR], 0.31 [0.17-0.57]; P < 0.001, I² = 43%). Furthermore, the rate of secondary intervention was significantly lower in the treatment group (OR, 0.12 [0.004-0.36]; P < 0.001, I² = 0%). After IMA embolization, type II endoleak resulted from patent lumbar arteries in all 62 patients with persistent endoleak.

CONCLUSIONS

Preoperative embolization of the IMA protects against the development of type II endoleaks and secondary interventions and may potentially lead to a rapid aneurysm sac regression. The procedure can be performed with a high technical success rate and minimal complications and should be considered in patients with IMA >3 mm before EVAR. A randomized trial, however, is required to clearly delineate the clinical significance of this technique.

Intraoperative Intrasac Thrombin Injection to Prevent Type II Endoleak after Endovascular Abdominal Aortic Aneurysm Repair

Purpose:

To report a prospective, nonrandomized pilot study to determine whether fibrin glue aneurysm sac embolization at the time of endovascular aneurysm repair (EVAR) is a safe and effective procedure to primarily prevent type II endoleaks.

Methods:

Between June 2003 and December 2005, 84 consecutive patients (79 men; mean age 73.8±7.8 years, range 64–86) with degenerative infrarenal abdominal aortic aneurysm underwent EVAR with bifurcated stent-grafts and fibrin glue injection into the aneurysm sac at the conclusion of the endovascular procedure. A total of 424 imaging studies and 348 visits were recorded during the study period and reviewed.

Results:

Selective catheterization of the aneurysm sac and fibrin glue injection immediately after initial stent-graft deployment was successful in 83 (99%) of 84 cases; there was one failure to access the excluded aneurysm sac due to severe iliac artery calcification. The estimated primary and assisted clinical success rates at 2 years were 91.3% and 98.8%, respectively, but the major findings were the low rate of delayed type II endoleak (2.4%) and the statistically significant decrease in the maximum transverse aneurysm diameter (50.40±6.70 versus 42.03±6.50 mm, p=0.0001) at follow-up. In addition, of 31 patients available for 24-month follow-up, 14 (45.2%) patients showed a reduction in maximum transverse aneurysm diameter by ≥5 mm; 16 (51.6%) patients had no significant changes, whereas only 1 patient showed a >5-mm enlargement.

Conclusion:

This clot engineering approach to aneurysm sac embolization at the time of endografting appears to be safe and may spare the patient a repeated catheter-based intervention or surgical procedure.

Strategies to Reduce the Rate of Type II Endoleaks: Routine Intraoperative Embolization of the Inferior Mesenteric Artery and Thrombin Injection into the Aneurysm Sac

Purpose:

To determine whether the rate of type II endoleaks following endovascular aneurysm repair (EVAR) can be decreased using a branch vessel management strategy.

Methods:

The branch vessel management strategy consisted of routine intraoperative embolization of all patent inferior mesenteric arteries (IMA) and thrombin injection into all aneurysm sacs that showed branch vessel filling on the “sacogram.” Sixty-nine consecutive patients (65 men; median age 77 years, range 58–90) undergoing elective EVAR since the protocol was introduced in July 2003 were included; 69 consecutive patients (65 men; median age 76 years, range 60–90) who underwent EVAR immediately prior to the protocol were used as controls. Primary outcome measures were type II endoleak rates and secondary intervention rates.

Results:

The median follow-up was 36 months (range 0.25–72) for the pre-protocol group and 12 months (range 0.25–24) for the post-protocol group. The type II endoleak rate for the pre-protocol group was 26% compared to 14% for the post-protocol group (p=0.14). This difference was not significant on Kaplan-Meir analysis (p=0.23). The 18 type II endoleaks in the pre-protocol group included 14 lumbar endoleaks, 1 IMA endoleak, and 3 combined lumbar and IMA endoleaks. The 10 type II endoleaks in the post-protocol group included 9 lumbar artery endoleaks and 1 IMA endoleak. Ten (14%) patients in the pre-protocol group required 15 interventions for type II endoleak compared to 2 (3%) in the post-protocol group who required 3 secondary procedures for type II endoleak (p=0.03). This difference was not significant on Kaplan-Meier analysis (p=0.22). Of the 12 interventions for lumbar endoleaks, only 5 (42%) were successful.

Conclusion:

Although there was a trend toward lower type II endoleak rates with our branch vessel management strategy, this did not reach statistical significance. Our data also indicated that there is a high incidence of lumbar endoleaks, and they are difficult to treat. Therefore, we believe there should be ongoing research into means to prevent lumbar endoleaks.

Type II endoleaks: challenges and solutions

Type II endoleaks are the most common endovascular complications of endovascular abdominal aortic aneurysm repair (EVAR); however, there has been a divided opinion regarding their significance in EVAR. Some advocate a conservative approach unless there is clear evidence of sac expansion, while others maintain early intervention is best to prevent adverse late outcomes such as rupture. There is a lack of level-one evidence in this challenging group of patients, and due to a low event rate of complications, large numbers of patients would be required in well-designed trials to fully understand the natural history of type II endoleak. This review will discuss the imaging, management, and outcome of patients with isolated type II endoleaks following infra-renal EVAR.

Risk factors and consequences of persistent type II endoleaks

OBJECTIVE

Type II endoleaks are common after endovascular aneurysm repair (EVAR), but their clinical significance remains undefined and their management controversial. We determined risk factors for type II endoleaks and associations with adverse outcomes.

METHODS

We identified all EVAR patients in the Vascular Study Group of New England abdominal aortic aneurysm database. Patients were subdivided into two groups: (1) those with no endoleak or transient type II endoleak and (2) persistent type II endoleak or new type II endoleak (no endoleak at completion of case). Patients with other endoleak types and follow-up shorter than 6 months were excluded. Multivariable analysis was used to evaluate predictors of persistent or new type II endoleaks. Kaplan-Meier and Cox regression analysis were used to evaluate predictors of reintervention and survival.

RESULTS

Two thousand three hundred sixty-seven EVAR patients had information on endoleaks: 1977 (84%) were in group 1, of which 79% had no endoleaks at all, and 21% had transient endoleaks that resolved at follow-up. The other 390 (16%) were in group 2, of which 31% had a persistent leak, and 69% had a new leak at follow-up that was not seen at the time of surgery. Group 2 was older (mean age, 75 vs 73 years; P < .001) and less likely to have chronic obstructive pulmonary disease (COPD; 24% vs 34%; P < .001) or elevated creatinine levels (2.6% vs 5.3%; P = .027). Coil embolization of one or both hypogastric arteries was associated with a higher rate of persistent type II endoleaks (12 vs 8%; P = .024), as was distal graft extension (12% vs 8%; P = .008). In multivariable analysis, COPD (odds ratio [OR], 0.7; 95% confidence interval [CI], 0.5-0.9; P = .017) was protective against persistent type II endoleak, while hypogastric artery coil embolization (OR, 1.5; 95% CI, 1.0-2.2; P = .044), distal graft extension (OR, 1.6; 95% CI, 1.1-2.3; P = .025), and age ≥ 80 (OR, 2.7; 95% CI, 1.4-5.3; P = .004) were predictive. Graft type was also associated with endoleak development. Persistent type II endoleaks were predictive of postdischarge reintervention (OR, 15.3; 95% CI, 9.7-24.3; P < .001); however, they were not predictive of long-term survival (OR, 1.1; 95% CI, 0.9-1.6; P = .477).

CONCLUSIONS

Persistent type II endoleak is associated with hypogastric artery coil embolization, distal graft extension, older age, the absence of COPD, and graft type, but not with aneurysm size. Persistent type II endoleaks are associated with an increased risk of reinterventions, but not rupture or survival. This reinforces the need for continued surveillance of patients with persistent type II endoleaks and the importance of follow-up to detect new type II endoleaks over time.

Predictive Factors for Type II Endoleaks after Treatment of Abdominal Aortic Aneurysm by Conventional Endovascular Aneurysm Repair

BACKGROUND

The aim of this study was to identify the predictive factors for the development of type II endoleaks (EL-II) after endovascular aneurysm repair (EVAR).

METHODS

We assessed the preoperative and postoperative computed tomography data of 308 patients who underwent EVAR between 2000 and 2012 and in 84 of whom primary or secondary EL-II occurred. The data analyzed were: demographics, number and diameter of lumbar arteries (LAs), inferior mesenteric artery (IMA), median sacral artery (MSA), accessory renal arteries (ARas), maximum diameter of infrarenal abdominal aortic aneurysm, diameter and length of proximal aortic neck. Statistical analysis was performed using Stata software (version 12). Categorical parameters were compared between groups using chi-squared or Fisher's exact tests as appropriate. Continuous variables were analyzed using Student's t-test or Mann-Whitney test as appropriate (normality studied by the Shapiro-Wilk and homoscedasticity verified using the Fisher-Snedecor test).

RESULTS

Of the 308 patients included (mean age, 73.8 ± 8.74 years), 284 (92%) were men, 61 (20%) were smokers, 113 (37%) had chronic obstructive pulmonary disease, 215 (70%) were taking antiplatelet. Respectively, 13, 51, 60, 103, 28, 40, 2, and 7 patients had 1, 2, 3, 4, 5, 6, 7, and 8 patent LAs. Before surgery, 221 IMAs and 136 MSA were patent. The sources of EL-II were: LA (n = 51), IMA (n = 22), MSA (n = 1), IMA and LA (n = 8), IMA and ARa (n = 1), and unknown (n = 1). Logistic regression models adjusting for clinically relevant covariables (age, American Society of Anesthesiologists, smoking status, dyslipidemia, and diuretics) were proposed to study morphologic EL-II predictive factors, first in the entire population, and then in the more specific population for whom IMA was patent. Risk factors of occurrence EL-II were: permeability of the IMA (70 patients [83%] vs. 155 [69%], P = 0.01), IMA diameter (3.49 mm vs. 2.71 mm, P < 0.001), number of LAs patent higher than or equal to 4 (P < 0.001), the mean LA diameter greater than 2.4 mm (P < 0.001), and MSA diameter (2.28 mm vs. 1.94 mm; P < 0.01).

CONCLUSIONS

Our results show the major role of the number and diameter of the patent aortic branches in the development of EL-II. As they can result in complications increasing the morbidity and mortality after EVAR, it is relevant to identify the risk factors of their occurrence.

Essentials of endovascular abdominal aortic aneurysm repair imaging: postprocedure surveillance and complications

OBJECTIVE

Lifelong postprocedural imaging surveillance is necessary after endovascular abdominal aortic aneurysm repair (EVAR) to assess for complications of endograft placement, as well as device failure and continued aneurysm growth. Refinement of the surveillance CT technique and development of ultrasound and MRI protocols are important to limit radiation exposure.

CONCLUSION

A comprehensive understanding of EVAR surveillance is necessary to identify life-threatening complications and to aid in secondary treatment planning.

Type 2 Endoleaks Post-EVAR: Current Evidence for Rupture Risk, Intervention and Outcomes of Treatment

Type 2 endoleaks (EL2) are the most commonly encountered endoleaks following EVAR. Despite two decades of experience, there remains considerable variation in the management of EL2 with controversies ranging from if to treat, when to treat and how to treat. Here, we summarise the available evidence, describe the treatment techniques available and offer guidelines for management.

Can early computed tomography angiography after endovascular aortic aneurysm repair predict the need for reintervention in patients with type II endoleak?

PURPOSE

This study was designed to identify parameters on CT angiography (CTA) of type II endoleaks following endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA), which can be used to predict the subsequent need for reinterventions.

METHODS

We retrospectively identified 62 patients with type II endoleak who underwent early CTA in mean 3.7 ± 1.9 days after EVAR. On the basis of follow-up examinations (mean follow-up period 911 days; range, 373-1,987 days), patients were stratified into two groups: those who did (n = 18) and those who did not (n = 44) require reintervention. CTA characteristics, such as AAA, endoleak, as well as nidus dimensions, patency of the inferior mesenteric artery, number of aortic branch vessels, and the pattern of endoleak appearance, were recorded and correlated with the clinical outcome.

RESULTS

Univariate and receiver operating characteristic curve regression analyses revealed significant differences between the two groups for the endoleak volume (surveillance group: 1391.6 ± 1427.9 mm(3); reintervention group: 3227.7 ± 2693.8 mm(3); cutoff value of 2,386 mm(3); p = 0.002), the endoleak diameter (13.6 ± 4.3 mm compared with 25.9 ± 9.6 mm; cutoff value of 19 mm; p < 0.0001), the number of aortic branch vessels (2.9 ± 1.2 compared with 4.2 ± 1.4 vessels; p = 0.001), as well as a "complex type" endoleak pattern (13.6 %, n = 6 compared with 44.4 %, n = 8; p = 0.02).

CONCLUSIONS

Early CTA can predict the future need for reintervention in patients with type II endoleak. Therefore, treatment decision should be based not only on aneurysm enlargement alone but also on other imaging characteristics.

Preoperative inferior mesenteric artery embolization before endovascular aneurysm repair: decreased incidence of type II endoleak and aneurysm sac enlargement with 24-month follow-up

PURPOSE

To review the effect of preoperative embolization of the inferior mesenteric artery (IMA) before endovascular aneurysm repair (EVAR) on subsequent endoleaks and aneurysm growth.

MATERIALS AND METHODS

Between August 2002 and May 2010, 108 patients underwent IMA embolization before EVAR. Coil embolization was performed in all patients in whom the IMA was successfully visualized and accessed during preoperative conventional angiography. In this cohort, the incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and repeat intervention were compared with a group of 158 consecutive patients with a patent IMA on preoperative computed tomography angiography but not on conventional angiography, who therefore did not undergo preoperative embolization.

RESULTS

The incidence of type II endoleak was significantly higher in patients not treated with embolization (49.4% [78 of 158] vs 34.3% [37 of 108]; P = .015). The incidence of secondary intervention for type II endoleak embolization was also significantly higher in those who did not undergo embolization (7.6% [12 of 158] vs 0.9% [one of 108]; P = .013). At 24 months, an increase in aneurysm sac volume was observed in 47% of patients in the nonembolized cohort (21 of 45), compared with 26% of patients in the embolized cohort (13 of 51; P = .03). No aneurysm ruptures or aneurysm-related deaths were observed in either group. One patient in the embolization group developed mesenteric ischemia and ultimately died.

CONCLUSIONS

Preoperative embolization of the IMA was associated with reduced incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and secondary intervention.

Quality improvement guidelines for imaging detection and treatment of endoleaks following endovascular aneurysm repair (EVAR)

Major concerns after aortic aneurysm repair are caused by the presence of endoleaks, which are defined as persistent perigraft flow within the aortic aneurysm sac. Diagnosis of endoleaks can be performed with various imaging modalities, and indications for treatment are based on further subclassifications. Early detection and correct classification of endoleaks are crucial for planning patient management. The vast majority of endoleaks can be treated successfully by interventional means. Guidelines for Imaging Detection and Treatment of endoleaks are described in this article.

Ischemic skin ulceration complicating glue embolization of type II endoleak after endovascular aneurysm repair

The optimal treatment for type II endoleaks remains unclear. The present report describes a case of ischemic skin ulceration after glue embolization of a type II endoleak with challenging access in a multiply comorbid 82-year-old woman with an expanding aneurysm sac 3 years after endovascular aneurysm repair. Embolization was performed from a proximal position with an n-butyl cyanoacrylate/Ethiodol mixture to allow flow into the endoleak because direct sac puncture was hazardous. One week after intervention, an eschar, which progressed to superficial necrosis as a result of partial nontarget delivery of sclerosant, developed over the left iliac crest. The eschar was self-limiting, with complete resolution by 6 months.

Endovascular aneurysm repair: current and future status

Endovascular aneurysm repair has rapidly expanded since its introduction in the early 1990s. Early experiences were associated with high rates of complications including conversion to open repair. Perioperative morbidity and mortality results have improved but these concerns have been replaced by questions about long-term durability. Gradually, too, these problems have been addressed. Challenges of today include the ability to roll out the endovascular technique to patients with adverse aneurysm morphology. Fenestrated and branch stent-graft technology is in its infancy. Only now are we beginning to fully understand the advantages, limitations, and complications of such technology. This paper outlines some of the concepts and discusses the controversies and challenges facing clinicians involved in endovascular aneurysm surgery today and in the future.

Complications of Endovascular Repair of Abdominal Aortic Aneurysms: A Review

The endovascular procedure for repair of abdominal aortic aneurysms has had an enormous impact on the treatment of this challenging disease. Complications, however, do occur and it is important to have a thorough understanding of the array of complications and appropriate management strategies. In this review of endovascular complications, we describe early and late complications paying particular attention to preventive, treatment and surveillance strategies.

Acute symptomatic abdominal aortic aneurysm secondary to endovascular stent graft associated type II endoleak

Endovascular abdominal aneurysm repair (EVAR) is popular because of its low invasiveness and feasibility for high-risk patients. Endoleak is common after EVAR and is characterized by blood flow within the aneurysm sac but outside the stent graft. Type II or collateral endoleak commonly results from retrograde filling of the aneurysm from collateral visceral vessels, lumbar, inferior mesenteric, accessory renal or sacral arteries. Collateral leaks are generally thought to be benign and over half of the early leaks will seal spontaneously. Sporadically, collateral endoleak could lead to aneurysm sac pressurization and place the patient at ongoing risk of rupture. Herein, we report an uncommon case of early post-stent graft placement symptomatic abdominal aortic aneurysm associated with type II endoleak.

Fate of Endoleaks Detected by CT Angiography and Missed by Color Duplex Ultrasound in Endovascular Grafts for Abdominal Aortic Aneurysms

PURPOSE

To analyze the clinical implications of endoleaks documented by computed tomographic angiography (CTA) and missed by color duplex ultrasound (CDU).

METHODS

During a recent 5-year period, 232 patients underwent endovascular aortic reconstruction (EVAR) and were followed according to a protocol that included CTA and CDU at 1 month and every 6 months thereafter. CTA was the gold standard for determining the presence of endoleaks. The size of the AAA sac at the latest postoperative follow-up was compared to the preoperative size and correlated to the type of endoleak and clinical outcome. This study analyzed only patients with endoleak documented by CTA and CDU and specifically analyzed the outcome of patients with false negative CDU studies for endoleaks.

RESULTS

Thirty-nine endoleaks were documented in 35 (15%) of 232 patients using CTA. Four patients had both early and late endoleaks. The mean follow-up was 25 months (range 1-64). CDU was more helpful in detecting type I endoleaks than type II endoleaks (89% versus 58%, p<0.05). There were 18 (46%) type I endoleaks (12 early, 6 late) detected by CTA; 16 (89%) of these were detected by CDU (2 late endoleaks missed). Nineteen (49%) type II endoleaks (16 early, 3 late) were diagnosed using CTA, 11 (58%) of which were detected by CDU (6 early and 2 late missed). Of the 2 (5%) early type IV endoleaks found on CTA, 1 (50%) was missed by CDU. Overall, CDU failed to identify endoleak in 11 (28%) of 39 endoleaks [2 late type I, 8 type II (6 early, 2 late), and 1 early type IV]. Consequences to treatment occurred in 2 (20%): 1 type I endoleak required treatment and 1 type II endoleak would have missed treatment.

CONCLUSION

CDU has a lower sensitivity in detecting endoleak, particularly type II; therefore, EVAR surveillance should not be based solely on CDU. Although a significant number of type II endoleaks resolved spontaneously, intervention can be offered for type II endoleaks if associated with an increasing sac size.

IMA Clipping for a Type II Endoleak

We describe herein a combined laparoscopic and endovascular approach to treat a type II endoleak due to retrograde flow in the patent inferior mesenteric artery (IMA). A 61-year-old gentleman presented with enlarging aneurysm sac confirmed on computed tomography scan evaluation after elective endovascular repair of an infrarenal abdominal aortic aneurysm. A combined laparoscopic and endovascular approach was used. After distal IMA was identified and marked with a clip laparoscopically, on-table angiography showed a proximal left colic branch and persistent flow in the IMA. Therefore, further laparoscopic exploration was performed by dissection along the distal branch. The origin of IMA was then located and subsequently sealed with 2 surgical clips. The completion angiography confirmed the proper position of the surgical clips and absence of endoleak. Our case demonstrated useful role of endovascular techniques in identifying the origin of IMA during laparoscopic approach for treating type II endoleak.

Type 2 Endoleaks after Abdominal Aortic Aneurysm Stent Grafting with Systematic Mesenteric and Lumbar Coil Embolization

We evaluated the results of our policy of systematic coil embolization of the inferior mesenteric artery (IMA) and/or lumbar arteries (LAs) prior to endovascular abdominal aortic aneurysm (AAA) repair (EVAR). We retrospectively reviewed all patients undergoing EVAR over a 4-year period at one hospital. Results were analyzed using uni- and multivariate analyses. Fifty-five male patients with an average age of 71 years were evaluated. Follow-up averaged 15 +/- 13 months. The IMA was either coiled or occluded in 30 cases. One or more LAs were coiled in 29 patients. An average of 1.3 LAs per patients were coiled (range 0-6). There were no immediate or late complications from coiling. At last follow-up, 14 AAAs showed no change in diameter, one increased by 2 mm, and the remainder (n = 40) decreased by 7.5 +/- 6 mm in maximal diameter. Only five (9%) type 2 endoleaks were detected during follow-up. Three were associated with AAA size increase. Four of the five were treated with additional coiling, with good results. By logistic regression, neither endoleak occurrence nor AAA shrinkage correlated with LA or IMA coiling. However, by multivariate analysis, completeness of lumbar coiling correlated negatively with aneurysm shrinkage (p = 0.04) and IMA coiling correlated positively with aneurysm shrinkage (p = 0.04). Coil embolization of the IMA and/or LAs prior to EVAR can be safely accomplished in a large number of cases and is associated with a low incidence of type 2 endoleaks. We cannot at present demonstrate a benefit to LA embolization in terms of endoleak prevention or AAA shrinkage. However, IMA embolization may be of benefit in terms of AAA shrinkage.