Aortic aneurysm sac filling with AneuFix injectable polymer during endovascular aneurysm repair: feasibility and safety trial study protocol.

INTRODUCTION: Type II endoleaks (T2ELs) following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) can lead to aneurysm growth, compromising the stent graft seal and risking rupture. Preventing these endoleaks during EVAR involves filling the AAA sac around the stent graft to exclude the aneurysm and block any arteries causing the endoleak. This study investigates the feasibility and safety of using AneuFix, a biocompatible injectable polymer developed by TripleMed (Geleen, the Netherlands), for aneurysmal sac filling during EVAR in high-risk T2EL patients. METHODS AND ANALYSIS: A feasibility, single-arm, single-centre clinical trial will initially include five patients with infrarenal AAA, eligible for EVAR, and at high risk for T2EL based on the number of patent lumbar arteries and the cross-sectional area of the aortic lumen at the level of the inferior mesenteric artery. Postevaluation by the Data Safety and Monitoring Board, the study cohort will extend to 25 patients. During EVAR and after stent graft deployment, the aneurysm sac is filled with AneuFix polymer using a filling sheath positioned parallel to the contralateral limb with the tip inside the aneurysm sac. Primary outcome is technical success (successful AAA sac filling). The secondary outcomes include clinical success at 6 and 12 months (occurrence of T2ELs and AAA growth assessed with CT angiography), intraoperative and perioperative complications, all endoleaks, adverse events, re-interventions, aneurysm rupture and patient survival. ETHICS AND DISSEMINATION: This trial was approved by the Dutch Authorities (Central Committee on Research Involving Human Subjects, IGJ), Amsterdam University Medical Centre Ethical Commission, and adheres to the Declaration of Helsinki and European Medical Device Regulation. Results will be shared at (inter)national conferences and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04307992.

Efficacy of Preemptive Embolization of Sac Branches During Endovascular Aneurysm Repair Using N-butyl-2-cyanoacrylate.

OBJECTIVE: A type 2 endoleak (T2EL) is the most frequently occurring endoleak type after endovascular aneurysm repair (EVAR). Residual T2ELs may cause aneurysm rupture; however, the management of a T2EL remains controversial. This study evaluated sac branch preemptive embolization using N-butyl-2-cyanoacrylate, aiming to prevent T2ELs and sac shrinkage. METHODS: Twelve consecutive patients underwent elective preemptive embolization during EVAR at our hospital between August 2018 to March 2019. Their demographic information, operative details, and sac diameters were examined at 6 months after EVAR. RESULTS: No procedural complications were observed. There were no in-hospital deaths among the 12 patients. Sac shrinkage was observed in this cohort (53.8-52.1 mm, p = 0.01). A total of 33 lumbar arteries were occluded with this procedure, and 2 patients had residual T2ELs at 6 months. CONCLUSIONS: A T2EL in preemptive sac branch embolization during EVAR has advantages in terms of safety and reduction. Although no clear evidence is available for the management of T2ELs, this study proposes a new standard to prevent it and improve the long-term outcomes after EVAR. However, embolization remains imperfect and further research is necessary.

Use of EndoAnchors during index endovascular aortic aneurysm repair in patients with hostile proximal aortic neck anatomy.

PURPOSE: Standard endovascular aortic aneurysm repair (EVAR) is sometimes the only treatment option for patients with hostile aortic neck anatomy, but it carries an increased risk of both early and late procedure-related complications. The aim of this study was to report on single-center experience with the Heli-FX EndoAnchors (Medtronic, Santa Rosa, CA) as an adjunctive procedure to endovascular aneurysm repair (EVAR) for prevention and perioperative treatment of proximal neck complications in patients with hostile neck anatomy.  MATERIALS AND METHODS: A single-centre, retrospective study evaluating 24 consecutive patients treated with EndoAnchors during the index EVAR procedure between November 2018 and August 2021. EndoAnchor implantation was indicated for cases with hostile proximal aortic neck anatomy characterised by the presence of at least one of the following parameters: length of 28 mm, angle of >60°, circumferential thrombus/calcification involving ≥50%, and reverse taper. RESULTS:  Median follow-up period was 22.5 months (IQR 2-31.5 months) with no aneurysm-related death, rupture, or conversion to open surgical repair during the follow-up. The procedural success rate was 100%, with no type Ia endoleak at the completion angiography. A mean of 7 EndoAnchors was used per patient (range 4-12). There were no EndoAnchor fractures and dislocations or stent graft fabric damage due to anchor implants. Twenty-three patients (95.8%) remained free of type Ia endoleak and migration on follow-up imaging. Aneurysm sac regression was observed in 13 patients (54.1%), while in 8 patients (33.3%) the sac remained stable. Sac enlargement was present in 1 patient (4.2%) due to late type Ia endoleak. Two patients were lost to the follow-up immediately after the procedure. Between two groups of patients (sac regression versus failure to regress), the larger initial diameter of the proximal neck was the only significant independent factor associated with a lower possibility of sac regression (p= 0,021). CONCLUSIONS:  The use of EndoAnchors during the index EVAR procedure in cases with challenging aortic neck anatomy with or without perioperative type Ia endoleak was associated with good midterm results and led to sac regression in most of the patients (Tab. 4, Fig. 3, Ref. 31).

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

OBJECTIVE: Type 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). METHODS: This 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. RESULTS: The 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. CONCLUSIONS: A 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.

OBJECTIVE: The 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). METHODS: CFT 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. RESULTS: Of 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). CONCLUSIONS: CFT 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.

Surgical Treatment for Sac Expansion Caused by Type II Endoleaks after Endovascular Aneurysm Repair of Abdominal Aortic Aneurysms/Iliac Aneurysms.

BACKGROUND: This study aimed to examine the outcomes of open surgery techniques involving sacotomy and suturing of the feeding vessels in patients with aneurysm sac expansion after endovascular aneurysm repair (EVAR). METHODS: Fourteen consecutive patients treated with sacotomy and suturing of feeding vessels for expanding aneurysm sacs with type II endoleaks following EVAR, between January 2018 and December 2022, were retrospectively included. All patients underwent preoperative digital subtraction angiography, and attempts were made to embolize the thick feeding vessels to reduce intraoperative bleeding. Age, sex, comorbidities, clinical presentation, aneurysm sac increase, morbidity, mortality, and follow-up were recorded. RESULTS: The median age of the patients was 72.89 ± 5.13 years old, and 13 (92.9%) patients were male. The sac size at the time of the open procedure was 107.89 ± 22.58 mm, and the extent of sac growth at the time of the open procedure was 37.50 ± 18.29 mm. The initial technical success rate of laparotomy and open ligation of the culprit arteries causing type II endoleaks was 92.9% (13/14). Among the patients, 5 (35.7%) had been treated with interventional embolization before the open procedure. One endograft was removed and replaced by a bifurcated Dacron graft because of distal dislocation in one patient. All patients recovered, and no deaths were recorded postoperatively. No patients had an eventful postoperative course or any subsequent graft-related complications during follow-up. CONCLUSIONS: Open surgical repair involving sacotomy and suturing of the feeding vessels appeared to have good outcomes in the treatment of patients with aneurysm sac expansion caused by type II endoleaks after EVAR. Preoperative embolization of feeding vessels can thus effectively reduce intraoperative bleeding.

Efficacy of Sac Coil Embolization in Endovascular Aortic Repair for Sac Shrinkage in Patients at a High Risk of Type II Endoleak from Lumbar Arteries.

BACKGROUND: In endovascular aortic repair (EVAR), preemptive embolization of sac branch vessels is effective in preventing postoperative type II endoleak (T2EL). However, this technique has not been widely adopted especially for lumbar arteries (LAs) because of technical difficulties and time constraints. This study aimed to investigate the efficacy of nonselective sac coil embolization, which is a simpler surgical method, in postoperative sac shrinkage for patients at a high risk of T2EL from LAs. METHODS: We retrospectively assessed 76 patients who underwent elective EVAR for abdominal aortic aneurysm with 4 or more patent LAs or at least 1 patent LA of ≥2 mm at our hospital between January 2014 and December 2022. The patients who underwent sac coil embolization were included in Group Ⅰ (n = 20), and the others were divided into 2 groups: those with an inferior mesenteric artery that was originally occluded or embolized by coils or stent graft bodies (Group Ⅱ, n = 21), and those without that (Group Ⅲ, n = 35). In Group Ⅰ, 0.035-inch coils were inserted into the sac after complete stent graft deployment. The cumulative incidence of sac shrinkage (≥5 mm) was compared between the groups. Further, univariable and multivariable Cox regression analyses were used to determine the predictors of sac shrinkage. RESULTS: Sac shrinkage (≥5 mm) was observed more frequently in Group Ⅰ (50%) than in Group Ⅱ (19%) and Group Ⅲ (17%) (P = 0.052 and 0.043, respectively). The cumulative incidence of sac shrinkage was significantly higher in Group Ⅰ than in Group Ⅱ (log-rank P = 0.039) and Group Ⅲ (log-rank P = 0.024). Multivariable Cox regression analyses revealed that sac embolization was a significant predictor of sac shrinkage (hazard ratio, 4.23; 95% confidence interval, 1.66-10.8; P = 0.003). CONCLUSIONS: Nonselective sac coil embolization in EVAR is potentially effective for sac shrinkage in the early postoperative phase in patients at high risk of T2EL from LAs. This simple procedure may improve prognosis after EVAR.

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

PURPOSE: To evaluate midterm results of whether the strategy to occlude target lumbar arteries using n-butyl-2-cyanoacrylate (nBCA) injection during endovascular aneurysm repair (EVAR) reduced the incidence of Type II endoleak (T2EL) after EVAR. MATERIALS AND METHODS: Between 2013 and 2020, 187 patients underwent EVAR; 106 in the treatment group received nBCA injection during EVAR, whereas 81 in the historical control group did not. The incidence of T2EL at 7 days, need for reintervention, and post-EVAR aneurysmal shrinkage were compared between the groups. RESULTS: Between the treatment group and the control group, significant differences were achieved in the incidence of T2EL (2.8% vs 28.4%; P < .0001) and decreased aneurysmal diameter was observed at 1 year after EVAR (-5.2 vs -3.8 mm; P = .034). In multivariate analysis, nBCA injection (odds ratio [OR], 0.04; P = .001) and younger age (OR, 0.92; P = .036) were significantly associated with a reduced incidence of T2EL. As a possible adverse event associated with nBCA injection, 2 cases of transient lower-limb motor dysfunction (1.9%) were observed. Propensity score analysis revealed that the treatment group had a significantly lower incidence of T2EL than that in the control group (P = .0002) even though there was no difference in the incidence of inferior mesenteric artery coil embolization between the groups. The survival rate without aneurysm sac enlargement (100.0% vs 69.8%; P = .014) and the reintervention-free rate (100.0% vs 63.1%; P = .034) in the treatment group were significantly higher than those in the control group. CONCLUSIONS: Concomitant nBCA injection can provide durable EVAR without T2EL, as supported by the avoidance of reintervention associated with aneurysm sac enlargement.

Endovascular aortic repair with sac embolization for the prevention of type II endoleaks (the EVAR-SE study): study protocol for a randomized controlled multicentre study in Germany.

BACKGROUND: Beyond a certain threshold diameter, abdominal aortic aneurysms (AAA) are to be treated by open surgical or endovascular aortic aneurysm repair (EVAR). In a quarter of patients who undergo EVAR, inversion of blood flow in the inferior mesenteric artery or lumbar arteries may lead to type II endoleak (T2EL), which is associated with complications (e.g. AAA growth, secondary type I endoleak, rupture). As secondary interventions to treat T2EL often fail and may be highly invasive, prevention of T2EL is desirable. The present study aims to assess the efficacy of sac embolization (SE) with metal coils during EVAR to prevent T2EL in patients at high risk. METHODS: Over a 24-month recruitment period, a total of 100 patients undergoing EVAR in four vascular centres (i.e. Klinikum rechts der Isar of the Technical University of Munich, University Hospital Augsburg, University Hospital Dresden, St. Joseph's Hospital Wiesbaden) are to be included in the present study. Patients at high risk for T2EL (i.e. ≥ 5 efferent vessels covered by endograft or aneurysmal thrombus volume <40%) are randomized to one group receiving standard EVAR and another group receiving EVAR with SE. Follow-up assessments postoperatively, after 30 days, and 6 months involve contrast-enhanced ultrasound scans (CEUS) and after 12 months an additional computed tomography angiography (CTA) scan. The presence of T2EL detected by CEUS or CTA after 12 months is the primary endpoint. Secondary endpoints comprise quality of life (quantified by the SF-36 questionnaire), reintervention rate, occurrence of type I/III endoleak, aortic rupture, death, alteration of aneurysm volume, or diameter. Standardized evaluation of CTA scans happens through a core lab. The study will be terminated after the final follow-up visit of the ultimate patient. DISCUSSION: Although preexisting studies repeatedly indicated a beneficial effect of SE on T2EL rates after EVAR, patient relevant outcomes have not been assessed until now. The present study is the first randomized controlled multicentre study to assess the impact of SE on quality of life. Further unique features include employment of easily assessable high-risk criteria, a contemporary follow-up protocol, and approval to use any commercially available coil material. Overcoming limitations of previous studies might help SE to be implemented in daily practice and to enhance patient safety. TRIAL REGISTRATION: ClinicalTrials.gov NCT05665101. Registered on 23 December 2022.