Patent Inferior Mesenteric Artery Research Articles

Five-year follow-up of randomized clinical trial for pre-emptive inferior mesenteric artery embolization during endovascular aneurysm repair

ObjectiveType II endoleak (T2EL) is the most common type of endoleak after endovascular aneurysm repair (EVAR) and a common indication for reintervention due to late sac enlargement. Although pre-emptive embolization of the inferior mesenteric artery (IMA) has been proposed to prevent this, no studies have prospectively demonstrated its efficacy. This study aimed to prove the validity of IMA embolization during EVAR in selective cases by analyzing the mid-term outcomes of a randomized clinical trial (RCT). MethodsThis single-center, parallel-group, non-blinded RCT included participants at high risk of T2EL, characterized by a patent IMA in conjunction with one or more following risk factors: a patent IMA ≥3 mm in diameter, lumbar arteries ≥2 mm in diameter, or an aortoiliac-type aneurysm. The participants were randomly assigned to two groups in a 1:1 ratio: one undergoing EVAR with IMA embolization and the other without. The primary endpoint was T2EL occurrence. The secondary endpoints included aneurysm sac changes and reintervention. In addition to RCT participants, outcomes of patients with low risk of T2EL were also analyzed. ResultsThe embolization and non-embolization groups each contained 53 patients. Five-year follow-up after the last patient enrollment revealed that T2ELs occurred in 28.3% and 54.7% of patients in the IMA embolization and non-embolization groups, respectively (P = .006). Both freedom from T2EL-related sac enlargement ≥5 mm and cumulative incidence of sac shrinkage ≥5 mm were significantly higher in the IMA embolization group than in the non-embolization group (95.5% vs 73.6% at 5 years; P = .021; 54.2% vs 33.6% at 5 years; P = .039, respectively). The freedom from T2EL-related sac enlargement ≥10 mm, an alternative indicator for T2EL-related reintervention, showed similar results (100% vs 90.4% at 5 years; P = .019). Outcomes in the low-risk group were preferable than those in the non-embolization group and comparable to those in the IMA embolization group. ConclusionsA lower threshold for pre-emptive IMA embolization when implementing EVAR would be more appropriate if limited to patients at high risk of T2ELs.

Midterm outcomes of endovascular repair for abdominal aortic aneurysm using the cuff-first technique to prevent type II endoleaks

ObjectiveThe aim of this study was to evaluate the initial and midterm outcomes of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) using the cuff-first technique (CFT) to prevent type II endoleak (T2EL). MethodsCFT involves deploying an aortic cuff inside the AAA to cover the ostium of the aortic side branch vessels before deploying the main body. We performed a retrospective review of all patients undergoing EVAR with CFT or side branch embolization (SBE) for AAAs at The Jikei University Hospital between 2016 and 2022. Primary endpoint was the rate of aneurysm sac shrinkage. Secondary endpoints were procedure time, radiation exposure, technical and clinical success rates, occurrence of T2EL, and freedom from reintervention or aneurysm-related death. ResultsOf 406 patients who underwent EVAR for AAAs, CFT was utilized in 56 (CFT group) and SBE in 35 (SBE group); all 91 patients were included in this study. There were no differences in patient demographics between groups, but there were differences in patency rate of the inferior mesenteric artery and absent intraluminal thrombus. The technical success rate per target vessel in the CFT and SBE group was 97.8% and 91.8%, and the clinical success rate was 91.0% and 100%, respectively. The median procedure time was shorter for CFT than for SBE: CFT, 10 (interquartile range [IQR], 6-14) minutes vs SBE, 25 (IQR, 18.5-45) minutes; P < .05), and median radiation exposure was lower for CFT than for SBE (CFT, 1455 (IQR, 840-2634) mGy vs SBE, 2353 (IQR, 1552-3586) mGy; P < .05). During the median follow-up of 25 months (IQR, 12.5-47 months), sac shrinkage occurred at similar rates in both groups (CFT, 37.5% vs SBE, 40.0%; P = .812), and there were no differences in freedom from reintervention (CFT, 96.2% and 91.4% at 12 and 36 months vs SBE, 100% and 89.5% at 12 and 36 months; log-rank P = .761) and freedom from aneurysm-related death (100% at 36 months in both groups; log-rank P = .440). The odds ratio of CFT vs SBE for sac regression was calculated by adjusting for inferior mesenteric artery patency and absent intraluminal thrombus, resulting in no statistical significance (odds ratio, 1.231; 95% confidence interval, 0.486-3.122). ConclusionsCFT is feasible with a shorter procedure time and lower radiation exposure than SBE and comparable mid-term outcomes, including sac shrinkage rate, compared with SBE. We believe that CFT, if anatomically suitable, is an alternative to SBE for the prevention of T2EL during EVAR.

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.

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

Factors associated with all-cause mortality following endovascular abdominal aortic aneurysm repair.

Background: Knowledge of factors that influence all-cause mortality after endovascular abdominal aortic aneurysm repair (EVAR) could improve therapeutic strategies post-EVAR and thus patient prognosis. Our study aimed to evaluate the association between sociodemographic information, comorbidities, laboratory parameters, treatment, selected anatomical and genetic factors and all-cause mortality post-EVAR. Patients and methods: We reviewed all patients who had undergone elective EVAR for non-ruptured abdominal aortic aneurysm (AAA) between January 2010 and December 2019. AAA size (maximum diameter and volume) was measured using CT-angiography. Sac expansion was defined as at least 5 mm increase, sac regression as at least 5 mm decrease in the sac diameter determined at 36±3 months post-EVAR in relation to pre-EVAR AAA diameter. Adjustments were performed for age, hypertension, diabetes mellitus, dyslipidaemia, sex, smoking, number of lumbar arteries, patency of inferior mesenteric artery and number of reinterventions post-EVAR. Results: One hundred and sixty-two patients (150 men, 12 women) with a mean age of 72.6±7.3 years were included in the analysis. Pre-EVAR AAA diameter (HR 1.07; 95% CI 1.03 - 1.12; p=0.001), pre-EVAR AAA volume (HR 1.01; 95% CI 1.002 - 1.011; p=0.008), post-EVAR sac diameter (HR 1.06; 95% CI 1.03 - 1.10; p=0.000), post-EVAR sac volume (HR 1.01; 95% CI 1.002 - 1.011; p=0.006) and anticoagulation therapy (HR 2.46; 95% CI 1.18 - 5.14; p=0.019) were associated with higher mortality in multivariate analysis. Sac regression (HR 0.42; 95% CI 0.22 - 0.82; p=0.011), and treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) (HR 0.71; 95% CI 0.36 - 0.97; p=0.047) were associated with lower mortality. Conclusions: Greater pre- and post-EVAR diameter and volume, failure of sac regression and anticoagulation were associated with higher mortality post-EVAR. Reduced mortality was observed in patients treated with ACE inhibitors or ARBs, and in patients with AAA sac regression.

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

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

Initial Clinical Experience With AneuFix Injectable Biocompatible Elastomer for Translumbar Embolization of Type 2 Endoleaks

The aim of this study was to assess the initial experience, technical success, and clinical benefit of AneuFix (TripleMed, Geleen, the Netherlands), a novel biocompatible and non-inflammatory elastomer that is directly injected into the aneurysm sac by a translumbar puncture in patients with a type II endoleak and a growing aneurysm. A multicenter, prospective, pivotal study was conducted (ClinicalTrials.gov:NCT02487290). Patients with a type II endoleak and aneurysm growth (>5 mm) were included. Patients with a patent inferior mesenteric artery connected to the endoleak were excluded for initial safety reasons. The endoleak cavity was translumbar punctured with cone-beam computed tomography (CT) and software guidance. Angiography of the endoleak was performed, all lumbar arteries connected to the endoleak were visualized, and AneuFix elastomer was injected into the endoleak cavity and short segment of the lumbar arteries. The primary endpoint was technical success, defined as successful filling of the endoleak cavity with computed tomography angiography (CTA) assessment within 24 hours. Secondary endpoints were clinical success defined as the absence of abdominal aortic aneurysm (AAA) growth at 6 months on CTA, serious adverse events, re-interventions, and neurological abnormalities. Computed tomography angiography follow-up was performed at 1 day and at 3, 6, and 12 months. This analysis reports the initial experience of the first 10 patients treated with AneuFix. Seven men and 3 women with a median age of 78 years (interquartile range (IQR), 74-84) were treated. Median aneurysm growth after endovascular aneurysm repair (EVAR) was 19 mm (IQR, 8-23 mm). Technical success was 100%; it was possible to puncture the endoleak cavity of all treated patients and to inject AneuFix. Clinical success at 6 months was 90%. One patient showed 5 mm growth with persisting endoleak, probably due to insufficient endoleak filling. No serious adverse events related to the procedure or AneuFix material were reported. No neurological disorders were reported. The first results of type II endoleak treatment with AneuFix injectable elastomer in a small number of patients with a growing aneurysm show that it is technically feasible, safe, and clinically effective at 6 months. Effective and durable embolization of type II endoleaks causing abdominal aortic aneurysms (AAA) growth after EVAR is challenging. A novel injectable elastic polymer (elastomer) was developed, specifically designed to treat type II endoleaks (AneuFix, TripleMed, Geleen, the Netherlands). Embolization of the type II endoleak was performed by translumbar puncture. The viscosity changes from paste-like during injection, into an elastic implant after curing. The initial experience of this multicentre prospective pivotal trial demonstrated that the procedure is feasible and safe with a technical success of 100%. Absence of AAA growth was observed in 9 out of 10 treated patients at 6 months.

Identifying Patients at High Risk for Post-EVAR Aneurysm Sac Growth.

Post-EVAR (endovascular aneurysm repair) aneurysm sac growth can be seen as therapy failure as it is a risk factor for post-EVAR aneurysm rupture. This study sought to identify preoperative patient predictors for developing post-EVAR aneurysm sac growth. A systematic review was conducted to select potential predictive preoperative factors for post-EVAR sac growth (including a total of 34.886 patients), which were evaluated by a retrospective single-center analysis of patients undergoing EVAR between 2009 and 2019 (N=247) with pre-EVAR computed tomography scans and at least 1 year follow-up. The primary study outcome was post-EVAR abdominal aortic aneurysm (AAA) sac enlargement (≥5 mm diameter increase). Multivariate Cox regression and Kaplan-Meier survival curves were constructed. Potential correlative factors for post-EVAR sac growth included in the cohort analysis were age, sex, anticoagulants, antiplatelets, renal insufficiency, anemia, low thrombocyte count, pulmonary comorbidities, aneurysm diameter, neck diameter, neck angle, neck length, configuration of intraluminal thrombus, common iliac artery diameter, the number of patent lumbar arteries, and a patent inferior mesenteric artery. Multivariate analysis showed that infrarenal neck angulation (hazard ratio, 1.014; confidence interval (CI), 1.001-1.026; p=0.034) and the number of patent lumbar arteries (hazard ratio, 1.340; CI, 1.131-1.588; p<0.001) were associated with post-EVAR growth. Difference in estimated freedom from post-EVAR sac growth for patients with ≥4 patent lumbar arteries versus <4 patent lumbar arteries became clear after 2 years: 88.5% versus 100%, respectively (p<0.001). Of note, 31% of the patients (n=51) with ≥4 patent lumbar arteries (n=167) developed post-EVAR sac growth. In our cohort, the median maximum AAA diameter was 57 mm (interquartile range [IQR] = 54-62) and the median postoperative follow-up time was 54 months (IQR = 34-79). In all, 23% (n=57) of the patients suffered from post-EVAR growth. The median time for post-EVAR growth was 37 months (IQR = 24-63). In 46 of the 57 post-EVAR growth cases (81%), an endoleak was observed; 2.4% (n=6) of the patients suffered from post-EVAR rupture. The total mortality in the cohort was 24% (n=60); 4% (n=10) was AAA related. This study showed that having 4 or more patent lumbar arteries is an important predictive factor for postoperative sac growth in patients undergoing EVAR. This study strongly suggests that having 4 or more patent lumbar arteries should be included in preoperative counseling for EVAR, in conjunction to the instructions for use (IFU).

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

Type 2 endoleaks (T2ELs) have been considered a benign condition and intervention is recommended when they are associated to sac expansion. The aim of this study was to report on T2EL embolization midterm outcomes, using neurointerventional material. A single-center retrospective analysis of consecutive patients treated with transarterial embolization, using neurointerventional material, for T2EL after standard endovascular aortic aneurysm repair (EVAR) between January 01, 2017 and July 30, 2022, was undertaken. Primary outcome was technical success and secondary outcome was T2EL recurrence during follow-up. Twenty six patients [92.3% males, mean age 73.9±7.7years] were included. The median time between EVAR and T2EL diagnosis was 12months (range: 1-84months). In 38.5% of patients, T2EL was detected at first month after EVAR. The time to embolization was 18months (range: 1-96months). In 42.3% of cases, a patent inferior mesenteric artery was suspected to relate to T2EL formation while in 42.3% of cases, a lumbar artery. Twelve procedures (38.4%) were performed using coils and Onyx and 13 (50%), using only Onyx. Technical success was 84.6%. The mean follow-up was 24months (range: 1-60months), including 20 patients. In 30% of cases, an T2EL recurrence was detected. Three patients (11.5%) underwent secondary embolization. Transarterial embolization for T2EL, using neurointerventional material, provided acceptable technical success and T2EL recurrence rates at 2years of follow-up. Longer follow-up data would further estimate the durability of the technique.

Factors Influencing on the Aneurysm Sac Shrinkage after Endovascular Abdominal Aortic Aneurysm Repair by the Analysis of the Patients with the Aneurysm Sac Shrinkage and Expansion.

Objectives: The aneurysmal sac shrinkage has been reported as the strong predictor of favorable long-term outcome after endovascular aneurysm repair (EVAR). We evaluated the effects of perioperative and intraoperative factors on the aneurysm sac shrinkage. Methods: EVAR was performed for 296 patients during August 2009-December 2021. Nine patients with type Ia, Ib, or III; 69 patients with the sac diameter change less than 5 mm; and five patients with sac re-expansion after shrunk more than 5 mm were excluded. Thus, patients with sac shrinkage 5 mm or more (79 patients, shrinkage group) and with sac expansion 5 mm or more (18 patients) were included in this study. Antifibrinolytic therapy with tranexamic acid (TXA) 1500 mg/day for 6 months after EVAR was introduced in March 2013 and patent aortic side branches were coil embolized during EVAR since July 2015. Patients' background and patent aortic side branches at the end of EVAR were evaluated. Results: Univariate analysis for comparison between patients with sac shrinkage and sac expansion revealed that males (82.3% vs. 55.6%, p = 0.021), without antiplatelet therapy (40.5% vs. 66.7%, p = 0.044) and TXA (79.8% vs. 38.9%, p <0.001), were significantly associated with sac shrinkage. By multivariate analysis, the odds ratio of sac shrinkage was 11.7 for males, 0.1 for the patients on antiplatelet therapy, and 6.5 for the patient who received TXA. The patients with patent inferior mesenteric artery (IMA) were less in the shrinkage group (20.3% vs. 77.8%, p <0.001) and with two or less patent lumbar arteries (LAs) were more in the shrinkage group (82.3% vs. 33.3%, p < 0.001). The odd ratio of sac shrinkage was 7.8 for occluded IMA and 3.9 for two or less patent LAs. Conclusion: The possibility of sac shrinkage would be high for the patient with occluded IMA and two or less patent LA at the end of EVAR, and that patient received TXA after EVAR. (This is a translation of Jpn J Vasc Surg 2022; 31: 291-297.).

Routine Inferior Mesenteric Artery Embolisation is Unnecessary Before Endovascular Aneurysm Repair

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

Abstract 9371: Effectiveness of Endovascular Aneurysm Repair With Inferior Mesenteric Artery Embolization From Mid-Term Outcome of a Randomized Controlled Trial

Introduction: Adequate management of type II endoleak (T2EL) has been widely discussed, and inferior mesenteric artery (IMA) embolization before endovascular aneurysm repair (EVAR) has been reported to reduce the T2EL. However, there have been no randomized controlled trials (RCT) confirming the efficacy. Thus, this study aimed to evaluate the effect of IMA embolization during EVAR in patients at high risk of T2EL in an RCT. Methods: This study included patients scheduled for elective EVAR between September 2014 and March 2018. Patients at high risk of T2EL (IMA patency with IMA ≥ 3 mm, LAs ≥ 2 mm, or an aortoiliac-type aneurysm) were prospectively randomized to receive EVAR with or without IMA embolization. The primary endpoint was T2EL occurrence during follow-up. The secondary endpoints were aneurysmal sac changes, adverse events from IMA embolization, and reintervention rate due to T2EL. Results: A total of 106 patients were randomized to the embolization group (group A, n = 53) or the nonembolization group (group B, n = 53). The technical success rate of IMA embolization was 88.7%, and no complications related to IMA embolization were observed. During the mean follow-up period—50.2 ± 21.9 months in group A and 52.9 ± 23.1 months in group B—the incidence of T2EL was significantly lower in the embolization group (23.9% in group A vs. 53.8% in group B; P &lt; 0.0001). Sac diameter changes, the incidence of aneurysmal sac growth (≥5 mm) related to T2EL, and freedom from sac enlargement (≥5 mm) related to T2EL at 5 years were –6.5 ± 8.9 mm vs. –1.1 ± 13.1 mm, 6.5% vs. 25.0%, and 97.5% vs. 72.0% in groups A and B, respectively (P = 0.015; P = 0.025; P = 0.018), which show that both shrinkage of aneurysm and freedom from sac enlargement are significantly higher in group A. Although no significant difference was observed in the reintervention rate due to T2EL (0% in group A vs. 2% in group B; P = 0.344), a significant difference in sac enlargement (≥10 mm) related to T2EL was observed (0% in group A vs. 13.5% in group B; P = 0.010), suggesting that reintervention would need to be considered. Conclusions: The results demonstrated the effectiveness of IMA embolization during EVAR in high-risk patients for the prevention of T2EL, which is suggested for avoiding aneurysmal sac enlargement related to T2EL.

Volumetric analysis of effectiveness of embolization for preventing type II endoleaks following endovascular aortic aneurysm repair

ObjectiveThe presence of endoleak was associated with the failure of endovascular aortic aneurysm repair (EVAR) treatment. The key to eliminating type II endoleak has shifted from reintervention to prevention. This study aimed to evaluate the effectiveness and safety of applying fibrin sealant to prevent type II endoleak in conjunction with EVAR. MethodsAll patients with abdominal aortic aneurysm who underwent EVAR from June 2019 to July 2021 were reviewed. Patients were grouped as Group A: standard EVAR with preemptive embolization and Group B: standard EVAR alone. The primary endpoint was the incidence of type II endoleak. The secondary endpoints were aneurysm sac regression, the inferior mesenteric artery patency, the numbers of patent lumbar arteries, and all-cause mortality. ResultsA total of 104 patients were included in Group A, and 116 were included in Group B. Technical success rate was 100%. The overall incidence of type II endoleak in Group A was significantly lower than that in Group B (4.8% vs 19.0%). The mean time of freedom from type II endoleak was 22.71 months for Group A (95% confidence interval, 21.59-23.83 months) and 19.89 months for Group B (95% confidence interval, 18.08-21.70 months). The Kaplan-Meier estimate of freedom from type II endoleak showed a significantly longer duration of freedom from type II endoleak in Group A (81.0% vs 95.2%). Group A showed a continuous sac regression tendency. In Group B, the sac volume decreased within 12 months but increased by 3.07 cm3 at 24 months. No complications were noted in both groups. ConclusionsNonselective preemptive embolization with porcine fibrin sealant during EVAR was safe and effective in preventing type II endoleak in the short and mid-term. Preemptive embolization can lead to a significantly higher sac regression rate. Larger patient populations and longer follow-ups with randomized control designed trials are expected to verify the long-term effectiveness and safety of preemptive embolization in preventing type II endoleak.

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.

Optimization of Type II Endoleak Embolization Using Onlay Fusion, Needle Assist Guidance, and Intraoperative Assessment with Contrast-enhanced Ultrasound

Effectiveness of type II endoleak (T2E) embolization is highly variable. The purpose of this study was to evaluate a protocol for T2E embolization using onlay fusion, needle assist guidance and intraoperative assessment with contrast-enhanced ultrasound (IO-CEUS). We reviewed the clinical data of 28 consecutive patients (89% male; mean age, 81 ± 11 years) treated for T2E using the standardized protocol from 2016 to 2019. Aneurysm sac embolization was performed using combination of 0.018-inch coils and ethylene vinyl alcohol copolymer (Onyx-18) via transarterial (Fig 1) or translumbar (Fig 2) approach. IO-CEUS was performed to determine resolution of T2E with additional embolization performed whenever needed. Technical success was defined by access to intended T2E nidus, successful delivery of embolic material, and absence of nontarget embolization. Clinical success was defined by technical success, absence or near complete resolution of T2E, and stabilization of aneurysm sac diameter on follow-up imaging. T2E embolization was indicated for significant aneurysm sac enlargement averaging 10 ± 7 mm at a mean follow-up of 50 ± 34 months from the index endovascular aortic repair (endovascular aneurysm repair [EVAR]) in 18 patients (64%) or fenestrated-branched EVAR in 10 patients (36%). Twelve patients (43%) had prior failed attempts to treat the T2E. Translumbar access was used in 23 patients (82%) and transarterial approach in 5 patients (18%), all of whom had patent inferior mesenteric arteries. T2E embolization was performed using Onyx-18 in 27 patients (96%) and coils in 25 patients (89%). Technical success was achieved in all patients. Completion IO-CEUS demonstrated complete T2E resolution in 20 patients (71%) and persistent, but reduced T2E in 8 patients (29%). There was no mortality. Nineteen patients (68%) were discharged to home on the same day. Mean length of hospital stay was 0.5 ± 0.7 days. After a mean follow-up of 19 ± 11 months, 23 patients (82%) had clinical success with aneurysm sac stabilization, with significantly higher rates among patients who had no T2E on completion IO-CEUS (95% vs 50%; P = .014). Of the five patients (18%) who had persistent aneurysm sac enlargement of 5 mm or more, two required additional T2E embolization procedures, both of whom had residual T2E on completion IO-CEUS. There were no aortic ruptures. A protocol using onlay fusion and needle assist guidance to facilitate aneurysm sac embolization and IO-CEUS assessment to document complete resolution of the T2E achieved clinical success in 82% of patients. Absence of residual T2E on completion IO-CEUS predicted higher rates of clinical success.Fig 2Type 2 endoleak (T2E)-treated with translumbar approach. We use on-lay fusion based on the most recent computed tomography angiography study and intraoperative cone beam computed tomography scan (A). The patient is positioned in lateral decubitus (B). A plan is created based on the preoperative CTA and needle assist track software is used to facilitate advancement of needle via translumbar access (C). Once embolization is completed, a contrast-enhanced ultrasound is performed to assess the area of embolization (D).View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Incidence and Fate of Refractory Type II Endoleak after EVAR: A Retrospective Experience of Two High-Volume Italian Centers.

Introduction: The aim of the present study is to report the outcome of patients presenting an isolated type II endoleak (TIIEL) requiring reintervention and to identify clinical and anatomical characteristics potentially implicated in refractory TIIEL occurrence and fate. Materials and Methods: A multicenter retrospective study on TIIEL requiring reintervention was conducted between January 2003 and December 2020. Demographic and clinical characteristics, procedural technical aspects, reinterventions, and outcomes were recorded. TIIEL determining sac expansion greater than 10 mm underwent a further endovascular procedure aiming to exclude aneurismal sac. Redo endovascular procedures were performed via endoleak nidus direct embolization and/or aortic side branches occlusion. TIIELs responsible for persisting aneurysmal sac perfusion 6 months after redo endovascular procedures were classified as “refractory” and submitted to open conversion. Results: A total of 102 TIIEL requiring reintervention were included in the final analysis. Eighty-eight (86.27%) patients were male, the mean age was 77.32 ± 8.08 years, and in 72.55% of cases the American Society of Anaesthesiologists (ASA) class was ≥3. The mean aortic diameter was 64.7 ± 14.02 mm, half of treated patients had a patent inferior mesenteric artery (IMA), and 44.11% ≥ 3 couples of patent lumbar arteries (LA). In 49 cases (48.03%) standard endovascular aneurysm repair (EVAR) procedure was completed without adjunctive maneuvers. All enrolled patients were initially submitted to a further endovascular procedure once TIIEL requiring reintervention was diagnosed; 57 patients underwent LAs or IMA embolization (55.87%), 42 transarterial aneurismal sac embolization (41.17%), and three (2.96%) laparoscopic ostial ligations of the inferior mesenteric artery. During a mean follow-up of 15.22 ± 7.57 months (7–48), a redo endovascular approach was able to ensure complete sac exclusion in 52 cases, while 50 patients presented a still evident refractory TIIEL and therefore a surgical conversion or semiconversion was conducted. At the univariate analysis refractory TIIEL patients were significantly different from those who did not develop the complication in terms of preoperative clinical, morphological characteristics, and initial EVAR procedures: coronary artery disease occurrence (p = 0.005, OR: 3.18, CI95%: 1.3–7.2); preoperative abdominal aortic aneurysm (AAA) sac diameter (p = 0.0055); IMA patency (p = 0.016, OR: 2.64, CI95%: 1.18–5.90); three or more patent LAs; isolated standard EVAR without adjunctive procedures (p > 0.0001; OR: 9.48, CI95%: 3.84–23.4). Conclusions: Our experience seems to demonstrate that it is reasonable to try to preoperatively identify those patients who will develop a refractory TIIEL after EVAR and those with a TIIEL requiring reintervention for whom a simple endovascular redo will not be enough, needing surgical conversion.

Significance of preoperative thrombus burden in the prediction of a persistent type II and reintervention after infrarenal endovascular aneurysm repair

BackgroundPersistent type II endoleak has necessitated prolonged surveillance and is a reason for reintervention after infrarenal 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 a persistent type II endoleaks. MethodsConsecutive patients who underwent infrarenal EVAR from October 2009 to October 2017 in a single vascular network were included. TB was assessed on preoperative computed tomography angiogram and was defined as a percentage of thrombus across the maximal sac diameter in comparison with the luminal diameter measured orthogonally at the same level. Patients were categorized into three groups: low TB (<25%), medium TB (25%-50%), and high TB (>50%). All patients underwent postoperative EVAR surveillance comprising computed tomographic angiography or duplex ultrasound imaging. Type II endoleak observed for more than 1 year was defined as persistent type II endoleak. Odds ratio (OR) and Student’s t-test were used to determine significance. ResultsSome 275 EVARs were performed in the study period. A total of 45 procedures were excluded because of either iliac-only intervention (n = 9), no preoperative 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, and comorbidities nor preoperative sac diameter. There was high interobserver 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 = .0003). Reintervention was also significantly more likely to occur in the presence of a persistent type II endoleak compared with its absence; n = 12 of 13 (92%) patients who underwent reintervention had a persistent type II endoleak (OR, 43.4 [5.5-242]; P = .0003). Sac size reduction was significantly greater in medium TB and high TB cohorts when compared with low TB: −25% and −27% vs −15% (P = .0046 and P < .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 with 40% where the IMA was occluded P < .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 with those with a high TB and an occluded IMA (OR, 34.1 [1.99-583]; P = .015). ConclusionsLow TB is associated with increased rates of persistent type II endoleak, especially in the presence of a patent IMA. High TB is associated with increased sac regression and low reintervention rates. TB can be assessed reliably and could be used for risk stratification in the planning of infrarenal EVAR. Pre-emptive embolization of IMA or lumbar vessels in those with low TB may be beneficial. TB could be a useful tool for designing a post-EVAR surveillance regimen.

Inferior Mesenteric Artery Revascularization for Salvage of Mesenteric Ischemia

Often sacrificed in favor of the celiac and superior mesenteric arteries, the inferior mesenteric artery (IMA) can provide crucial inflow to the abdominopelvic viscera and spinal cord, especially in the presence of concomitant celiac or superior mesenteric artery (SMA) disease. We sought to elucidate the presentation and course of patients who had undergone IMA-specific revascularization. A retrospective analysis was performed of IMA revascularization procedures performed at an urban quaternary center from 2010 to 2020. Patients were included if concomitant renal artery, celiac artery, or SMA revascularization had been performed. Angioplasty, stenting, and open procedures were included. The patient characteristics, indications, and perioperative and long-term outcomes were analyzed. From 2010 to 2020, 10 patients had met the inclusion and exclusion criteria. Of the 10 patients, 9 were women (90%). Their median age was 71 years (range 47-88), and 80% had a history of smoking. Six patients had undergone elective IMA revascularization for chronic disease. Of the remaining four patients with acute symptoms, two had presented with an acute-on-chronic exacerbation of symptoms. All four patients with acute symptoms had presented as hospital transfers and had undergone intervention within 12 hours of transfer. However, two patients had had symptoms lasting >8 days before transfer. The 10 patients had undergone 16 procedures. Of the 10 patients, 8 had undergone IMA stenting, 1 had undergone percutaneous transluminal angioplasty alone, and 1 had undergone open IMA and aortic endarterectomy with patch angioplasty. Four patients had received concomitant celiac artery or SMA revascularization, with a large meandering mesenteric artery determining the choice to revascularize the IMA. In the six patients without celiac artery or SMA revascularization, three patients had had known SMA and celiac artery occlusions, and one had had a known occluded celiomesenteric trunk. In the four patients with acute symptoms, three small bowel resections and two laparotomies without bowel resection were performed. Six patients had required intensive care unit admission. Seven patients had had >1 year patency or had been lost to follow-up without known failure of IMA revascularization. Two patients died within 30 days with patent IMAs after withdrawal of care because of necrotic small bowel requiring resection. Two patients had undergone aortovisceral bypass after IMA occlusion—one patient on the day after IMA stenting and one patient at 17 months after IMA stenting. Revascularization of the IMA can serve as a reliable salvage option for patients with chronic or acute-on-chronic mesenteric ischemia, and should be considered for patients with high-grade stenosis or occlusion of the celiac artery and SMA.

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

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

Risk Analysis of Aneurysm Sac Enlargement Caused by Type II Endoleak after Endovascular Aortic Repair

Although the preoperative risk factors associated with the occurrence of type II endoleak (ETII) after endovascular aortic repair (EVAR) have gradually become more evident, the preoperative risk factors associated with aneurysm sac enlargement caused by ETII remain unclear. This study aimed to determine the preoperative risk factors associated with aneurysm sac enlargement caused by ETII after EVAR. This retrospective cohort study reviewed 519 EVARs performed for true abdominal aortic aneurysm between January 2006 and December 2018 at our institution. EVARs using commercially available bifurcated devices with no type I or III endoleaks during follow-up and with ≥12 months follow-up were included. A total of 320 patients were enrolled in the study. To identify the preoperative risk factors of sac enlargement after EVAR, Cox regression analysis was used to assess preoperative data. The median follow-up period was 60.8 months. Overall, 135 of 320 patients (42%) had ETII during follow-up, and 47 of 135 patients (35%) developed aneurysm sac enlargement. Multivariate analysis revealed that chronic kidney disease (CKD) stage ≥4 (hazard ratio [HR], 4.65; 95% confidence interval [CI], 2.13-10.15; P=0.001), patent inferior mesenteric artery (IMA) (HR, 17.85; 95% CI, 2.46-129.73; P< 0.001), and number of patent lumbar arteries (LAs) (HR, 1.37; 95% CI, 1.13-1.68; P= 0.002) were risk factors of aneurysm sac enlargement caused by ETII. CKD stage ≥4, patent IMA, and number of patent LAs were independent risk factors for aneurysm sac enlargement after EVAR. In particular, patent IMA had the highest HR and seemed to have the greatest impact on long-term aneurysm sac enlargement. Hence, taking preoperative measures to address a patent IMA appears to be important in reducing the incidence of sac enlargement.

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

PurposeTo evaluate the impact of preemptive inferior mesenteric artery (IMA) embolization on outcomes of endovascular abdominal aortic aneurysm (AAA) repair (EVAR). Materials and MethodsFrom 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. ResultsA 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. ConclusionsPreventive 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.