Systematic review and meta-analysis of prophylactic aortic side branch embolization to prevent type II endoleaks

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Safety of preoperative branch embolization in patients undergoing evar

The purpose of this systematic review is to evaluate the safety of pre-endovascular abdominal aortic aneurysm repair (EVAR) embolization of aortic side branches - the inferior mesenteric artery and lumbar arteries. Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed. A search of MEDLINE and DIMENSION databases identified 9 studies published from 2011 to 2021 that satisfied the inclusion and exclusion criteria. These studies were analyzed to detect the incidence of embolization-related complications. A total of 482 patients underwent preoperative aortic side branch embolization, 30 (6.2%) of whom suffered some kind of minor complication. The only major complication observed was ischemic colitis in 4 (0.82%) patients, two (0.41%) of whom died after bowel resection surgery. Regarding these findings, aortic side branch embolization seems to be a safe procedure, with very low percentages of both minor and major complications.

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.

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

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

Purpose

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

Material and Methods

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

Results

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

Conclusions

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

Patent iliolumbar artery increase no risk of type II endoleaks after endovascular abdominal aortic aneurysm: a case-control study

Objective

The aims of the present study were to explore the risk factors for type 2 endoleaks (T2ELs) after endovascular aneurysm repair (EVAR) and the association between T2ELs and the iliolumbar artery.

Materials and methods

A single-center, retrospective case-control study in West China Hospital was conducted among patients with infrarenal abdominal aortic aneurysm (AAA) who underwent EVAR between June 2010 and June 2019. The associations of patient characteristics, anatomical factors, internal iliac artery embolization, and ILA with the primary outcome were analyzed. The secondary objective was to analyze survival and reintervention between the T2EL group and the non-T2EL group. Kaplan-Meier survival, propensity matching analysis and multivariate logistic regression analysis were used.

Results

A total of 603 patients were included. The median follow-up was 51 months (range 5.0-106.0). There was a significant difference in the diameter of the lumbar artery (LA), middle sacral artery (MSA) and inferior mesentery artery (IMA), proportion of thrombus and LA numbers. The univariate analysis showed that T2ELs were more likely to develop more thrombus in aneurysm cavity (OR = 0.294, p = 0.012), larger MSA (OR = 1.284, p = 0.04), LA (OR = 1.520, p = 0.015), IMA (OR = 1.056, p < 0.001) and more LAs (OR = 1.390, p = 0.019). The multivariate analysis showed that the number of LAs (HR: 1.349, 95% CI: 1.140-1.595, p < .001) and the diameter of the IMA (HR: 1.328, 95% CI: 1.078-1.636, p = 0.008) were significantly associated with T2ELs. There were no new findings from the propensity score matching. The reintervention-free survival rates were significantly different between the two groups (p = 0.048). Overall survival and AAA-related death rates were not different between the two group. This was consistent with the PSM analysis.

Conclusion

The iliolumbar artery and the different internal iliac artery interventions may not increase the incidence of T2ELs. But the numbers of LAs and IMA diameter were independent risk factors for T2Els. T2ELs was associated with the reintervention but did not affect long-term survival or increase aneurysm-related mortality after EVAR.

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.

Abdominal Aortic Aneurysm Shrinkage up to 2 Years Following Endovascular Repair with PEmbolization for Preventing Type 2 Endoleak: A Retrospective Single Center Study

BACKGROUND

The aim of the present study was to evaluate the efficacy of preemptive embolization of aneurysm side branches that cause type 2 endoleak (T2EL).

METHODS

We performed a retrospective review of consecutive patients who underwent endovascular aneurysm repair (EVAR) in our facility between April 2009 and April 2019. All the patients underwent the preemptive embolization for preventing T2EL since April 2014. The patients were divided into the nonembolization group (between April 2009 and May 2014) or the embolization group (between April 2014 and April 2019). We used a support wire to improve a success rate of the preemptive embolization. The aneurysm sac shrinkage (≧5 mm), freedom from all-cause death and aneurysm-related death, T2EL-related reinterventions, aneurysm sac enlargement (≧5 mm), and complications related to the endovascular procedure were compared between the 2 groups.

RESULTS

Two-hundred patients with abdominal aortic aneurysm were included. They were divided into the nonembolization group (N = 103) and the embolization group (N = 97). We successfully embolized 89% of all the patent aneurysm side branches in the embolization group. The characteristics of the 2 groups were similar except for hypertension, patent lumbar arteries, and the use of Zenith, Excluder, and Endurant. The preemptive embolization group showed better aneurysm sac shrinkage (73% vs. 42%; P < 0.0001), no aneurysm sac enlargement (0% vs. 5%; P < 0.05), and lower T2EL-related reintervention rate (hazard ratio, 0.11; 95% confidence interval, 0.0061-0.60; P < 0.01) up to 2 years after EVAR. There were no significant differences in freedom from all-cause death, aneurysm-related death, and complications between the 2 groups.

CONCLUSIONS

The present study showed the high success rate of preemptive embolization of aneurysm side branches resulting in better anatomical changes in the aneurysm sac and lower T2EL-related intervention rate in the embolization group up to 2 years after EVAR.

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.

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.

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.

Impact of proximal neck anatomy on short-term and mid-term outcomes after treatment of abdominal aortic aneurysms with new-generation low-profile endografts. Results from the multicentric "ITAlian north-east registry of ENDOvascular aortic repair with the BOltOn Treo endograft (ITA-ENDOBOOT)"

INTRODUCTION

The aim of the study was to evaluate the short-term and mid-term technical and clinical outcomes of the Bolton Treo endograft in subjects with abdominal aortic aneurysm (AAA) requiring endovascular aortic repair (EVAR) and assess if presence of hostile proximal neck would represent a risk factor for increased failure rates.

METHODS

A retrospective review of all consecutive patients who had undergone elective or non-elective EVAR with the Bolton Treo endograft at five institutions located in the North-East of Italy (January 2016-December 2020) was performed. The main exposure variable for this study was presence of hostile (HAN) or friendly (FAN) aortic neck.

RESULTS

A total of 137 consecutive patients were treated with the Bolton Treo endograft at participating institutions; of these 63 (46%) presented HAN while 74 (54%) had FAN. At baseline, no significant differences were observed in the distribution of demographics and comorbidities between study groups. Two type Ia endoleaks (EL) were detected at completion angiography, all in patients with HAN but none in patients with FAN (3% vs 0%, p=.04), but no type III EL were identified in the whole cohort. The median duration of follow-up in the study cohort was 30 months (IQR 22-34 months) and was similar between study groups (p=.87). At three-years, survival estimates were 89% and 91% (p=.82) in patients with HAN and FAN, respectively. At three years, patients with HAN had significantly lower freedom from type IA endoleak as compared with patients with FAN (87% vs 94%, p=.02). No significant differences were found between study groups in the three-year estimates of freedom from reinterventions (80% vs 86%, p=.28). Using cox proportional hazards, presence of type II EL (HR 3.15, 95%CI 1.18-8.5, p=.02) and presence of type IA EL (HR 4.22, 95%CI 1.39-12.85, p=.01) were found as independent predictors for reinterventions in univariate analysis, although they were no longer significant in the multivariate model. Freedom from sac increase >5mm at three years were not significantly different between study groups (92% vs 91%, p=.95).

CONCLUSIONS

Within a contemporary multicentric real-world experience, EVAR with the Bolton Treo endograft shows a satisfactory safety profile in the immediate postoperative phase and acceptable outcomes during mid-term follow-up. Presence of HAN is correlated with development of type Ia EL (either early following stent-graft implantation or late after EVAR) which, in turn, may represent a significant factor leading to reinterventions.

[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.

Dynamic, Time-Resolved Computed Tomography Angiography Technique to Characterize Aortic Endoleak Type, Inflow and Provide Guidance for Targeted Treatment

PURPOSE

To illustrate dynamic, time-resolved CTA (d-CTA) imaging technique in characterizing aortic endoleak type/inflow using quantitative parameters and its value in providing image guidance for targeted treatment approach.

TECHNIQUE

Dedicated endoleak protocol involved acquiring multiple time-resolved contrast enhanced scans using third-generation CT scanner (Somatom Force^®, Siemens Healthineers). Parameters such as scan field of view (FOV), kV, number/timing of scans were customized based on patient's body-mass-index, timing bolus, and prior imaging findings. D-CTA image datasets were evaluated qualitatively and quantitatively using time-attenuation curves (TAC) analysis after motion correction using a dedicated software (syngo.via^®, Siemens). D-CTA findings from 4 illustrative cases demonstrating type I, type II (inferior mesenteric and lumbar artery inflow), and type III endoleak were illustrated. TAC analysis with time to peak parameter enabled better characterization of endoleak type and inflow. During endoleak intervention, target vessels from d-CTA images were electronically annotated and overlaid on fluoroscopy using 2D-3D image fusion to provide image guidance for targeted treatment.

CONCLUSION

D-CTA imaging with TAC analysis characterizes aortic endoleak type and inflow, in addition to providing image guidance for targeted endoleak treatment. Such dynamic, time-resolved imaging techniques may provide further insights into understanding aortic endoleak that remains an Achilles heel for endovascular aortic aneurysm repair.

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.

Outcomes of Preventive Embolization of the Inferior Mesenteric Artery during Endovascular Abdominal Aortic Aneurysm Repair

PURPOSE

To evaluate the impact of preemptive inferior mesenteric artery (IMA) embolization on outcomes of endovascular abdominal aortic aneurysm (AAA) repair (EVAR).

MATERIALS AND METHODS

From January 2015 to July 2017, all patients undergoing elective EVAR or fenestrated EVAR (F-EVAR) for asymptomatic AAA in a single tertiary hospital were retrospectively included. Three groups of patients were defined: patients with a patent IMA who underwent embolization during EVAR/F-EVAR (group 1), those with a patent IMA who did not undergo embolization during EVAR/F-EVAR (group 2), and those with a chronically occluded IMA (group 3). Preoperative aortic morphology, demographics, and procedural details were recorded. Aneurysmal growth (≥5 mm), reintervention, and overall mortality rates were analyzed using multivariate proportional hazard multivariate modeling. Propensity scores were constructed, and inverse probability weighting was applied to a new set of multivariate analyses to perform a sensitivity analysis.

RESULTS

A total of 266 patients (male, 95% [n = 249]) with a median age of 70 (65-77) years were included, with F-EVAR procedures comprising 87 (32.7%) of the interventions. There were 52, 142, and 72 patients in groups 1, 2, and 3, respectively. Changes in aneurysmal sac size did not differ between groups, nor did overall survival or reintervention rates at 24 months. IMA embolization was not identified as an independently protective factor for aneurysmal growth during follow-up (relative risk [RR] = 2.82/mm [0.96-8.28], P = .060), whereas accessory renal arteries (RR = 5.07/mm [1.72-14.96], P = .003) and a larger preoperative aneurysmal diameter (RR = 1.09/mm [1.03-1.15], P = .004) were independent risk factors for sac enlargement.

CONCLUSIONS

Preventive embolization of the IMA during EVAR or F-EVAR did not promote aneurysmal sac shrinking or decrease the reintervention rate at 2-year follow-up.

High aneurysm wall enhancement values are associated with late sac shrinkage after endovascular repair of abdominal aortic aneurysms

To analyze the correlation between aneurysm wall enhancement (AWE) values and early and late sac shrinkage after endovascular aneurysm repair (EVAR).We retrospectively analyzed 28 patients who underwent EVAR for abdominal aortic aneurysms (AAA) using a bifurcated main body stent graft. The value of AWE in the slice of the maximum AAA diameter was measured using a volumetric analysis of computed tomography images. Sac measurements before EVAR and more than 10 months after EVAR were compared, and the maximum sac shrinkage rate was calculated.The AWE value immediately after (4 to 7 days) EVAR correlated positively with the sac shrinkage rate (R2 = 0.0139). The AWE value at 6 months after EVAR was also strongly correlated with the sac shrinkage rate (R2 = 0.4982).Higher AWE values at 6 months after EVAR were strongly associated with the sac volume shrinkage rate. High AWE values may be a predictive factor for sac shrinkage and may aid in the selection of the appropriate clinical strategy after EVAR.