Sac Embolization Research Articles

The usefulness of contrast-enhanced subtraction magnetic resonance imaging for detecting endoleaks after endovascular aortic repair with prophylactic intraoperative sac embolization.

Metallic and hyperdense artifacts and T1-shortening substances in the abdominal aortic aneurysm (AAA) sac generated by embolic materials and lipiodol pose challenges in the identification of endoleaks on follow-up computed tomography (CT) or magnetic resonance imaging (MRI). To evaluate the usefulness of contrast-enhanced subtraction MRI (CES-MRI) for detecting endoleaks after endovascular abdominal aortic aneurysm repair (EVAR) with intraoperative AAA sac embolization compared with CE-CT, this study was conducted. In this study, 28 consecutive patients who underwent EVAR with prophylactic AAA sac embolization were included. All patients underwent CES-MRI and CE-CT to detect endoleaks. The definitive diagnosis of endoleaks was a consensus reading of CE-CT and CES-MRI by two certified radiologists, in addition to angiography or reproducible radiological findings in the observational examination. Analysis was performed to evaluate which examination was better for detecting endoleaks. The sensitivity, specificity, and area under the curve of CE-CT and CES-MRI according to observer 1 were 50%, 100%, and 0.813 (95% confidence interval [CI] = 0.625-1.00) and 100%, 95%, and 0.997 (95% CI = 0.984-1.00), respectively, and those according to observer 2 were 50%, 100%, and 0.750 (95% CI = 0.514-0.986) and 100%, 95%, and 0.969 (95% CI = 0.903-1.00), respectively. Intolerable artifacts were significantly observed on CE-CT. The severity of the artifacts did not depend on the stent graft on CT and MRI. Although no significant difference was observed, CES-MRI tended to have better accuracy for endoleak detection in EVAR with intraoperative AAA sac embolization than CE-CT.

Evaluating the feasibility of contrast-enhanced ultrasound for detecting after preemptive coiling endoleaks in endovascular aortic aneurysm repair: A pilot study

Endovascular aortic aneurysm repair is widely used for the treatment of abdominal aortic aneurysm (AAA), but has a 10% to 40% incidence of type II endoleak during follow-up. There are various techniques to treat these endoleaks in the case of enlarging of the AAA, but the clinical effectiveness is low. In recent years, preemptive AAA sac embolization has shown some encouraging results with significant AAA shrinkage. However, the presence of embolic material can complicate continued endoleak detection making assessment of treatment outcome difficult. We investigate the ability of contrast-enhanced-ultrasound examination to detect endoleaks in patients undergoing preemptive coil embolization of the AAA sac.

Treatment strategy for splenic artery aneurysms and novel classification based on imaging

ObjectiveThe incidence of splenic artery aneurysms (SAAs) has increased with advances in imaging techniques, necessitating a comprehensive classification to guide treatment strategies. This study aims to propose a novel classification system for SAAs based on aneurysm characteristics and to review treatment outcomes at our center. MethodsThis retrospective study included 113 patients with SAAs admitted to Peking Union Medical College Hospital from January 2019 to December 2023, assessed using computed tomography angiography or digital subtraction angiography. A new classification system was devised based on the aneurysm location, morphology, integrity, and parent artery anatomy. Treatment strategies were determined based on these characteristics, with interventions ranging from endovascular therapy to laparoscopic and open surgery. Patients were followed up after the intervention to assess mortality, complications, reinterventions, and aneurysm-related outcomes. ResultsThe study cohort of 113 patients with 127 SAAs had a predominance of female patients (63.7%) and a mean age of 52.7 years. The SAAs were classified into five types, with type I being the most common. The intervention techniques varied across types, with sac embolization, covered stent implantation, and artery embolization being the most frequently used. The overall technical success rate was 94.7%, with perioperative complication and reintervention rates of 25.0% and 0.9%, respectively, and no deaths within 30 days after the intervention. The median follow-up duration was 21 months, with overall complications rate of 3.5% and no aneurysm-related complications or deaths. ConclusionsThe proposed classification system effectively guides the selection of treatment strategies for SAAs, incorporating key anatomical and morphological features. This system facilitated high technical success and low complication rates, underscoring the importance of tailored techniques in managing SAAs.

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

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. 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 ≥2mm 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 (≥5mm) was compared between the groups. Further, univariable and multivariable Cox regression analyses were used to determine the predictors of sac shrinkage. Sac shrinkage (≥5mm) 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). 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.

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

BackgroundBeyond 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.MethodsOver 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.DiscussionAlthough 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.

Long-term Impact of Preemptive Nonselective Perigraft Aortic Sac Embolization During Endovascular Aortic Repair

Long-term Impact of Preemptive Nonselective Perigraft Aortic Sac Embolization During Endovascular Aortic Repair

Injectable Shear-Thinning Hydrogels with Sclerosing and Matrix Metalloproteinase Modulatory Properties for the Treatment of Vascular Malformations.

Sac embolization of abdominal aortic aneurysms (AAAs) remains clinically limited by endoleak recurrences. These recurrences are correlated with recanalization due to the presence of endothelial lining and matrix metalloproteinases (MMPs)-mediated aneurysm progression. This study incorporated doxycycline (DOX), a well-known sclerosant and MMPs inhibitor, into a shear-thinning biomaterial (STB)-based vascular embolizing hydrogel. The addition of DOX was expected to improve embolizing efficacy while preventing endoleaks by inhibiting MMP activity and promoting endothelial removal. The results showed that STBs containing 4.5% w/w silicate nanoplatelet and 0.3% w/v of DOX were injectable and had a 2-fold increase in storage modulus compared to those without DOX. STB-DOX hydrogels also reduced clotting time by 33% compared to untreated blood. The burst release of DOX from the hydrogels showed sclerosing effects after 6 h in an ex vivo pig aorta model. Sustained release of DOX from hydrogels on endothelial cells showed MMP inhibition (ca. an order of magnitude larger than control groups) after 7 days. The hydrogels successfully occluded a patient-derived abdominal aneurysm model at physiological blood pressures and flow rates. The sclerosing and MMP inhibition characteristics in the engineered multifunctional STB-DOX hydrogels may provide promising opportunities for the efficient embolization of aneurysms in blood vessels.

Early outcomes of the Conformable endograft in severe neck angulation from the Triveneto Conformable Registry

ObjectiveThe study reports retrospective evaluation of early outcomes from a multicentric experience with the Excluder conformable endograft with active control system (CEXC Device) in the treatment of abdominal aortic aneurysms. Its design allows more flexibility, given by proximal unconnected stent rows and a bending wire within the delivery catheter enables control of proximal angulation. This study specifically focuses on the severe neck angulation (SNA) subgroup (≥60°). MethodsAll patients treated with CEXC Device in nine vascular surgery centers of Triveneto area (Northeast Italy) between January 2019 and July 2022 were enrolled prospectively and analyzed retrospectively. Demographic and aortic anatomical characteristics were evaluated. Endovascular aneurysm repair in SNA were selected for analysis. Major investigated outcomes were technical success, endoleaks, morbidity, mortality, and reinterventions at 30 days and during follow-up. Endograft migration and postoperative aortic neck angulation changes were also analyzed. ResultsA total of 129 patients were enrolled. An infrarenal angle of ≥60° was observed in 56 patients (43%) (SNA group) and their data analyzed. The mean patient age was 78.9 ± 5.9 years and median abdominal aortic aneurysm diameter 59 mm (range, 45-94 mm). Median aortic infrarenal neck length, angulation and diameter were 22 mm (range, 13-58 mm), 77° (range, 60°-150°), and 22.0 ± 3.5 mm respectively. Analysis revealed a technical success rate of 100% and perioperative major complication rate of 1.7%. Intraoperative and perioperative morbidity and mortality rates were 3.5% (one buttock claudication and one inguinal surgical cutdown) and 0%, respectively. No perioperative type I endoleaks were observed. The median follow-up was 13 months (range, 1-40 months). Five patients died during follow-up from aneurysm-unrelated causes. Two reinterventions occurred (3.5%): one conversion for a type IA endoleak and one sac embolization for a type II endoleak. Aneurysm sac shrinkage was observed in 15 patients (26%) and aneurysm stability in 35 patients (62%), respectively. Estimated freedom from reinterventions at 24 months was 92%. Aortic neck median postoperative angulation was 75° (range, 45°-139°). ConclusionsThe Triveneto Conformable Registry shows good early results of the CEXC device in severely angulated aortic infrarenal necks. These data need confirmation on longer follow-up and a wider cohort of patients to further increase endovascular aneurysm repair eligibility in SNA.

Feasibility of aortic aneurysm sac embolization using a novel shape memory polymer embolic device

BackgroundWe investigated the feasibility of aneurysm sac embolization using a novel self-expanding porous shape memory polymer (SMP) device during endovascular aortic abdominal or thoracic aneurysm repair (EVAR).MethodsRetrospective analysis of consecutive patients treated at 2 centers in Germany. Patients were treated from January 2019 to July 2021 with follow-up at 7 days and 3, 6, and 12 months. Aneurysm sacs were implanted with SMP devices immediately following endograft placement during the same procedure. Primary endpoint was technically successful SMP-device deployment into the aneurysm sac outside the endograft. Secondary endpoints were changes in aneurysm volume and associated complications (e.g., endoleaks).ResultsWe included 18 patients (16 males), aged 72 ± 9 years, achieving 100% technical success. Mean preprocedure aortic aneurysm sac volume was 195 ± 117 mL with a perfused aneurysm volume of 97 ± 60 mL. A mean of 24 ± 12 SMP devices per patient were used (range 5–45, corresponding to 6.25–56.25 mL expanded embolic material volume). All evaluable patients exhibited sac regression except 2 patients yet to reach 3-month follow-up. At mean 11 ± 7 months (range 3–24), change in aneurysm volume from baseline was -30 ± 21 mL (p < 0.001). In 8 patients, aneurysm regression was observed despite type 2 endoleaks in 6 and type 1A endoleaks in 2, none of them requiring further intervention to date. No morbidity or mortality related to this treatment occurred.ConclusionsSMP devices for aortic aneurysm sac embolization during endovascular repair appear feasible and safe in this small case series. Prospective studies are needed.Key points• Shape memory polymer is a novel, self-expanding, porous, and radiolucent embolic device material.• Aortic aneurysm sacs were treated with polymer devices immediately following endograft placement.• Aortic aneurysm sac regression was observed in all patients with over 3-month follow-up.• Aortic aneurysm sac regression was observed even in the presence of endoleaks.

Endovascular Aneurysm Sac Embolization for Treatment of Ruptured Aneurysms in the Aortoiliac Segment Using N-Butyl-Cyanoacrylate.

Background Aneurysmal rupture in the aortoiliac segment is a severe, life-threatening condition. Nowadays, in addition to surgical treatment, the implantation of a covered stent graft constitutes a feasible, minimally invasive treatment option. A novel approach is the add-on of transarterial aneurysm sac embolization with N-butyl-cyanoacrylate (NBCA). Here, we report our experience of performing this add-on embolization procedure after endovascular aneurysm repair for complex ruptured aneurysms of the aortoiliac segment. Material and Methods We describe six patients (mean age of 75.2 years; all male) with ruptured aneurysms in the visceral aortic and aortoiliac segment in whom a high-volume transarterial aneurysm sac embolization was performed as an add-on therapy to the implantation of an aortic prosthesis. The aim of this add-on intervention was to achieve the definite embolization of the aneurysmal rupture site and to ensure the best possible aneurysmal sealing. We report the feasibility, technical success, and considerations of using NBCA as well as clinical and follow-up imaging results, given their availability. Results Technical success was achieved in all cases. Clinical success was achieved in four cases. No periprocedural complications or reinterventions were reported. The mean full procedure time was 107.8 min. The mean radiation dose was 12,966.1 cGy/cm2. A mean amount of 10.7 mL of NBCA mixed with lipiodol in a 1:3 to 1:5 ratio was used for all patients. Available follow-up imaging up to 36 months after the procedure showed no aneurysm progression or endoleaks. In two patients, the NBCA cast had almost fully dissolved over the course of follow-up. Conclusions Our study underscores the notion that aneurysm sac embolization using high volumes of NBCA with ethiodized oil as an embolic agent is a feasible and add-on treatment option for optimizing the exclusion of the aneurysm from patients with ruptured aneurysms in the aortoiliac segment.

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

Type II endoleaks (ELII) are the most common complication following endovascular aneurysm repair (EVAR). Persistent type II endoleaks require continual surveillance and have been shown to increase the risk of Type I and III endoleaks, sac growth, need for intervention, conversion to open or even rupture directly or indirectly. These are often difficult to treat following EVAR and there are limited data regarding the effectiveness of prophylactic treatment of ELII. The aim of this study is to report midterm outcomes of prophylactic perigraft arterial sac embolization (pPASE) performed in patients undergoing EVAR. This is a comparison of two elective cohorts of those undergoing EVAR using the Ovation stent graft with and without prophylactic branch vessel and sac embolization. Patients who underwent pPASE at our institution had data collected in a prospective, IRB approved database. These were compared against the core lab adjudicated data from the Ovation IDE trial. Prophylactic PASE was performed at the time of EVAR with thrombin, contrast and gelfoam if lumbar or mesenteric arteries were patent. Endpoints included freedom from ELII, reintervention, sac growth, all-cause mortality (ACM) and aneurysm-related mortality (ARM). Thirty-six patients (13.1%) underwent pPASE, while 238 patients (86.9%) had standard EVAR. Median follow-up was 56 months (IQR 33-60). The 4-year freedom from ELII estimates were 84% for the pPASE vs 50.7% for the standard EVAR group (P=0.0002). All aneurysms in the pPASE group remained stable in size or demonstrated regression, whereas aneurysm sac expansion was seen in 10.9% of the standard EVAR group, P=0.03. At 4 years, mean AAA diameter decreased by 11mm (95% CI 8-15) in the pPASE group vs 5mm (95%CI 4-6) for the standard EVAR group, P=0.0005. There were no differences in the 4-year freedom from ACM and ARM. However, the difference in reintervention for ELII trended toward significance (0.0% vs 10.7%, P=0.1). On multivariable analysis, pPASE was associated with a 76% reduction in ELII [aHR(95%CI): 0.24 (0.08-0.65), P=0.005]. These results suggest that pPASE in those undergoing EVAR is safe and effective in the prevention of EII and significantly improves sac regression over standard EVAR while minimizing the need for reintervention.

Efficacy and safety of prophylactic intraoperative sac embolization in EVAR for abdominal aortic aneurysm: A meta-analysis.

We aimed to investigate the effectiveness and safety of prophylactic sac embolization during endovascular aneurysm repair (EVAR) in patients suffering from abdominal aortic aneurysms. We performed a systematic literature search of PubMed, Web of Science, EMbase, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP, Wanfang and China Biomedical Literature Database (CBM) to identify studies evaluating the outcomes of sac embolization vs. no embolization among patients who had received EVAR. The time limit of the search was from the establishing database to July 22, 2022. Outcome measures involved the type II endoleak rate, the other endoleak rate, the reintervention rate, mortality, and operation time. Fixed (no heterogeneity) or random effects models were constructed for each outcome. The outcomes are represented as the odds ratio (OR) with a 95% confidence interval (CI). Among the 2,622 studies screened, 13 studies involving 747 participants were included in the review. The incidence of early-term type II endoleak (OR = 0.2, 95% CI (0.13,0.31), P < 0.00001), mid-term type II endoleak (OR = 0.23, 95% CI (0.15,0.37), P < 0.00001), late-term type II endoleak (OR = 0.27, 95% CI (0.16,0.46), P < 0.00001) and reintervention (OR = 0.50, 95% CI (0.37,0.78), P = 0.002) within the sac embolization group were significantly lower than those in the non-embolization group. No significant differences were observed between the two groups were found for the other endoleak rates (OR = 0.67, 95% CI (0.34,1.32), P = 0.25), mortality (OR = 0.64, 95% CI (0.25,1.66), P = 0.36) and operation time operation (MD = 5.76, 95% CI (-8.30,19.83), P = 0.42). EVAR combined with sac embolization effectively reduces the incidence of type II endoleak and the reintervention rate without enhancing the operation time. Therefore, more high-quality studies are still needed for validation due to the limited amount and quality of included literature. https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022365648.

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

This study aimed to evaluate the effect of aggressive embolization of side branches arising from the aneurysmal sac before endovascular aneurysm repair. This retrospective study included 95 patients who underwent endovascular infrarenal abdominal aortic aneurysm repair at Tottori University Hospital between October 2016 and January 2021. Of these, 54 underwent standard endovascular aneurysm repair (conventional group), and 41 underwent coiling of the inferior mesenteric and lumbar arteries before undergoing endovascular aneurysm repair (embolization group). The occurrence of type II endoleak, change in aneurysmal sac diameter, and reintervention rate due to type II endoleak during follow-up were evaluated. Compared to the conventional group, the embolization group had a significantly lower incidence of type II endoleak, more frequent aneurysmal sac shrinkage, and lower aneurysmal sac growth related to type II endoleak. Our results demonstrated the effectiveness of aggressive aneurysmal sac embolization before endovascular aneurysm repair to prevent type II endoleak and the consequent long-term aneurysmal sac enlargement.

Percutaneous contrast-enhanced ultrasound-guided transabdominal sac embolization is an effective technique for treating complicated type II endoleaks after endovascular aneurysm repair

Objective: In the present study, we evaluated and compared the outcomes of transarterial embolization with those of percutaneous contrast-enhanced ultrasound-guided transabdominal sac embolization (PUSE) for type II endoleaks (T2ELs).

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.

In-vitro Assessments of Clot Elicitation by Thrombogenic Fibers vs. Embolization Coils.

Late and persistent type II endoleaks (EL2) following Endovascular Aneurysm Repair (EVAR) have been recognized as an independent and significant risk factor for aneurysm sac growth and secondary procedures. Solutions are available for treatment, with varying success rates; preventive perioperative sac embolization with coils appears safe and effective. The objective of this study is to compare whole blood coagulation elicited by a textile stent-graft equipped with thrombogenic, patented "Kardiozis" fibers (PKF) to that elicited by embolization coils in an in vitro study. The approach is to establish an equivalence between PKF and coils in a static model, then to compare clot elicitation by both materials in a perfused model aneurysm chamber subjected to EL2. The weight of clot elicited during exposure to blood was the primary measurement. In the static model, PKF and coils were soaked in blood for up to 90 minutes (N = 30) and elicited similar clotting. In the dynamic model, stent-grafts equipped with PKF or coils were exposed to blood flow inside an aneurysm model for up to 3h (N = 5), with generally higher clot weights for stent-grafts with PKF (non-significant). Complete thrombosis of the aneurysm model was observed in one experimental series (positive control and stent-graft with PKF). A stent-graft with PKF elicits at least as much clot as embolization coils dispersed in an aneurysm model chamber under continuous blood flow. PKF positioned on the outer wall of stent-grafts could have a similar action as coiling of the aneurysm sac during the index EVAR.

Successful Sac Embolization to Eliminate a Type 2 Endoleak After Thoracic Endovascular Aortic Repair by Penetration of a Vascular Plug Implanted in a Left Subclavian Artery

Purpose: To describe a technique of vascular plug penetration by a guidewire with a heavy tip load for additional embolization of a type 2 endoleak after endovascular aortic aneurysm repair (EVAR). Technique: The technique of vascular plug penetration is effective for additional embolization of a type 2 endoleak, when large arteries such as left subclavian artery (LSA) or hypogastric artery remain patent even after the embolization of the vessel has been performed using a vascular plug and are responsible for the endoleak. A tapered guidewire with a heavy tip load enables the penetration of the disk of the plug, followed by introduction of a microcatheter into the endoleak nidus. In the presented case, the technique successfully eliminated a type 2 endoleak in a thoracic aortic aneurysm for which a patent LSA despite the embolization by a vascular plug was responsible. Conclusion: The technique of vascular plug penetration allows an access to an endoleak cavity via a vascular plug placed in an aortic side branch for additional embolization of a type 2 endoleak after EVAR.

Percutaneous contrast-enhanced ultrasound-guided transabdominal sac embolization is an effective technique for treating complicated type II endoleaks after endovascular aneurysm repair

ObjectiveIn the present study, we evaluated and compared the outcomes of transarterial embolization with those of percutaneous contrast-enhanced ultrasound-guided transabdominal sac embolization (PUSE) for type II endoleaks (T2ELs). MethodsA retrospective review was conducted of consecutive patients who had undergone T2EL embolization between January 2015 and December 2020 at our center. The cohort was divided into two groups according to the embolization approach: PUSE vs transarterial. Freedom from aneurysm growth, safety, immediate technical success, freedom from persistent T2ELs, and the repeat embolization rate were assessed. ResultsA total of 25 patients and 28 embolization procedures (PUSE, n = 16; transarterial embolization, n = 12) were examined. Both the fluoroscopic time (13.3 ± 3.2 minutes vs 35.0 ± 7.0 minutes; P < .001) and the procedural time (84.9 ± 8.4 minutes vs 117.1 ± 14.8 minutes; P < .001) were significantly shorter in the PUSE group than in the transarterial group. After the embolization procedure, the patients were followed up for a mean duration of 24.7 ± 14.9 months for the PUSE group and 35.9 ± 21.1 months for the transarterial group (P = .1323). Five patients in the transarterial group had undergone unsuccessful embolization, with success in 7 of the 12 patients in the transarterial group and all 16 patients in the PUSE group (P = .0081). Failure had resulted from failed transarterial access or a recurrent T2EL. Three of the five patients had undergone subsequent PUSE during follow-up. No patient in the PUSE group had experienced sac expansion compared with four patients in the transarterial group (P = .0242). Similarly, no patient in the PUSE group had developed a newly discovered T2EL vs four patients in the transarterial group (P = .0242). Thus, the outcomes were markedly better for the PUSE group than were those for the transarterial group. A major procedure-related complication (abdominal abscess) occurred in one patient in the transarterial group. ConclusionsPUSE is safe and effective for managing T2ELs. It yields better outcomes in terms of preventing aneurysm growth, decreasing the incidence of repeat embolization and complications, minimizing the recurrence of T2ELs, and reducing the fluoroscopic and procedural times. We, thus, regard it as the preferred approach for the management of T2ELs.

Pulmonary Arteriovenous Malformation Embolization: So Much Left to Learn

Embolization of pulmonary arteriovenous malformations (PAVMs) has been utilized effectively for more than 40 years. Initially performed using conventional coils and/or detachable balloons in the era of cut-film angiography, currently, there is an armamentarium of embolic devices and methods for effecting therapy. Two studies in this issue of the Journal of Vascular Interventional Radiology compare traditional feeding artery embolization with venous sac (“nidal”) embolization, and in both, sac embolization appeared to improve the occlusion rate of lesions (1,2).