Visceral Artery Aneurysms Embolization and Other Interventional Options: State of the Art and New Perspectives

Added Value of Selective Intra-arterial Cone-Beam CT Angiography in the Management of Visceral Artery Aneurysms

PURPOSE

The aim of this study is to evaluate the value of selective intra-arterial cone-beam computed tomography angiography (CBCTA) relative to conventional computed tomography angiography (CTA) in understanding visceral artery aneurysm (VAA) morphology, and its impact on treatment planning.

MATERIALS AND METHODS

Between January 2017 and August 2021, all patients who had a diagnosis of VAA and underwent intraoperative CBCTA imaging were retrospectively reviewed. Impact on treatment decisions, optimal C-arm angulations derived from CBCTA, and additional radiation exposure were reported. Two blinded independent reviewers qualitatively reviewed CBCTA and conventional CTA images. A 5-point Likert scale (1=poor image quality, 5=excellent image quality) was used to assess the overall image quality of each modality. Number of vessels arising from the aneurysm sac was counted.

RESULTS

A total of 16 patients had a diagnosis of VAA during the study period, of whom 10 patients had intraoperative CBCTA and conventional CTA available for review. Out of 10 patients, 7 underwent successful endovascular treatment, 2 were deemed not amenable for endovascular embolization based on intraoperative CBCTA findings, and 1 had resolved pseudoaneurysm. Total fluoroscopy time and radiation dose (dose area product [DAP] and skin dose) for all procedures were 27.7 ± 19.9 minutes, 28 362 (±18 651) µGy*m2, and 1879 (±1734) mGy, respectively. Radiation exposure from CBCTA (DAP and skin dose) was 5703 (±3967) µGy*m2 and 223.6 (±141.3) mGy, respectively. In patients who underwent endovascular treatment, the proportional DAP from CBCTA was 18.3% (±15.3%) of the total procedural radiation dose. Qualitative rating of overall image quality of CBCTA images was superior to CTA images (mean score: 4.55 vs 3, p<0.001). More branch vessels arising from the VAA were identified by all reviewers in CBCTA as compared with conventional CTA (median, min-max: 3, 0-4 vs 2,1-3 vessels).

CONCLUSION

Intraoperative CBCTA after selective intra-arterial contrast injection, with better spatial resolution, provided better delineation of visceral aneurysm morphology as compared with conventional, intravenous CTA and enabled optimal treatment planning at a reasonable additional radiation exposure.

CLINICAL IMPACT

Visceral artery aneurysms (VAA) are often diagnosed incidentally by conventional computed tomographic angiography (CTA). Endovascular treatment typically requires selective angiographies at multiple projections to better understand aneurysm morphology, location, and efferent branch vessels. Intra-arterial cone-beam CT angiography (CBCTA) for VAA has the advantage of selective contrast opacification, better spatial resolution, and three-dimensional/multi-planar visualization of aneurysm morphology. In addition, CBCTA enables identification of optimal C-arm working projection for subsequent endovascular treatment. The aim of this study is to evaluate the value of intraoperative CBCTA relative to conventional CTA in understanding visceral artery aneurysm morphology and its impact on treatment planning.

Gastroduodenal artery aneurysm - an extremely rare but insidious cause of abdominal pain: a case report

An arterial aneurysm is a localized weakening of the artery wall that results in pathological dilatation. All intra-abdominal artery aneurysms are labeled as visceral artery aneurysms (VAA), apart from the aorto-iliac artery aneurysms. VAA´s are rare, gastroduodenal artery aneurysms (GDAA), constituting 1.5% of visceral artery aneurysms. A woman in her early 80s´ presented with chronic epigastric pain, weight loss, and nausea. Conservative management was unsuccessful. Imaging revealed a GDAA, prompting endovascular coil embolization. Subsequent evaluation confirmed Polyarteritis Nodosa (PAN), treated with rituximab. The report underscores the diagnostic challenges, emphasizing the need for a multidisciplinary approach using imaging and angiography. GDAA's potential life-threatening rupture necessitates prompt intervention, as illustrated in this case. The rare association with PAN, although infrequent, underscores the importance of considering underlying etiologies in multiple visceral aneurysms. Early diagnosis and intervention are pivotal for this uncommon yet potentially lethal condition.

Splenic Artery Infectious Aneurysms in Infective Endocarditis - An Observational Study and Comprehensive Literature Review

BACKGROUND

To determine the prevalence, the clinical and radiological features, associated factors, treatment, and outcome of splenic artery aneurysms (SAAs) in infective endocarditis (IE).

METHODS

We retrospectively reviewed 474 consecutive patients admitted to our institution with definite IE (2005-2020).

RESULTS

Six patients had SAAs (1.3%; 3 women; mean age: 50 years). In all cases, the diagnosis was obtained by abdominal computed tomography angiography (CTA). SAAs-IE were solitary and saccular with a mean diameter of 30 mm (range: 10-90 mm). SAAs-IE were intrasplenic (n = 4) or hilar (n = 2). Streptococcus spp. were the predominant organisms (n = 4). In all cases, a left-sided native valve was involved (aortic, n = 3; mitral, n = 2; mitral-aortic, n = 1). SAAs were silent in half patients and were revealed by abdominal pain (n = 2) and by the resurgence of fever after cardiac surgery (n = 1). All patients underwent emergent valve replacement. One patient died within 24 hr from multiorgan failure. For the others, uneventful coil embolization was performed in 4 patients after valve replacement (3 diagnosed early and 1 at 8 weeks). In the remaining patient, SAA-IE diagnosed at abdominal CTA at day 16, with complete resolution under appropriate antibiotherapy alone.

CONCLUSIONS

SAAs-IE are a rare occurrence that may be clinically silent. SAAs-IE can be intrasplenic or hilar in location. Endovascular treatment in this context was safe. According to current guidelines, radiologic screening by abdominal CTA allowed the detection of silent SAAs which could be managed by endovascular treatment to prevent rupture. The delayed formation of these SAAs could justify a CTA control at the end of antibiotherapy.

Ruptured Mycotic Aneurysm of the Superior Mesenteric Artery: A Case Report

An infected (mycotic) aneurysm of the visceral arteries is an uncommon entity, which may arise from a secondary infection of a preexisting aneurysm or be due to degeneration from a primary infection. Mycotic aneurysms require prompt recognition and definitive treatment; otherwise, there can be devastating morbidity and mortality. We present the case of a 51-year-old female with HIV and Crohn's disease who presented with subacute abdominal pain, nausea, and vomiting and was found to have an ultimately fatal mycotic aneurysm of the superior mesenteric artery. In addition, we discuss the characteristic imaging features of mycotic aneurysms on computed tomography and magnetic resonance imaging.

Guidelines on the diagnosis, treatment and management of visceral and renal arteries aneurysms: a joint assessment by the Italian Societies of Vascular and Endovascular Surgery (SICVE) and Medical and Interventional Radiology (SIRM)

The objective of these Guidelines is to provide recommendations for the classification, indication, treatment and management of patients suffering from aneurysmal pathology of the visceral and renal arteries. The methodology applied was the GRADE-SIGN version, and followed the instructions of the AGREE quality of reporting checklist. Clinical questions, structured according to the PICO (Population, Intervention, Comparator, Outcome) model, were formulated, and systematic literature reviews were carried out according to them. Selected articles were evaluated through specific methodological checklists. Considered Judgments were compiled for each clinical question in which the characteristics of the body of available evidence were evaluated in order to establish recommendations. Overall, 79 clinical practice recommendations were proposed. Indications for treatment and therapeutic options were discussed for each arterial district, as well as follow-up and medical management, in both candidate patients for conservative therapy and patients who underwent treatment. The recommendations provided by these guidelines simplify and improve decision-making processes and diagnostic-therapeutic pathways of patients with visceral and renal arteries aneurysms. Their widespread use is recommended.

CIRSE Standards of Practice for the Endovascular Treatment of Visceral and Renal Artery Aneurysms and Pseudoaneurysms

BACKGROUND

Endovascular treatment of visceral and renal artery aneurysms and pseudoaneurysms is an effective, minimally invasive treatment that has been successfully used since the early 1990s, with refined and expanded techniques and tools currently offering excellent outcomes. Due to increased detection of such lesions in recent years, many of which are asymptomatic, revision of the indications for intervention and the correct endovascular treatment approaches has become essential.

PURPOSE

This document will presume that the indication for treatment is clear and approved by the multidisciplinary team and will define the standards required for the performance of each intervention, as well as their relative advantages and limitations. CIRSE Standards of Practice documents are not intended to impose a standard of clinical patient care, but recommend a reasonable approach to, and best practices for, the performance of the endovascular treatment of visceral and renal artery aneurysms and pseudoaneurysms.

METHODS

The writing group was established by the CIRSE Standards of Practice Committee and consisted of five clinicians with internationally recognised expertise in endovascular treatments. The writing group reviewed the existing literature on visceral and renal artery aneurysms and pseudoaneurysms, performing an evidence search using PubMed to identify publications in English and relating to human subjects from 1990 to 2022. The final recommendations were formulated through consensus.

RESULTS

Endovascular treatment has an established role in the successful management of visceral and renal artery aneurysms and pseudoaneurysms, and this Standards of Practice document provides up-to-date recommendations for its safe performance.

Spontaneous Resolution of Recurrent Pancreatitis After Splenic Artery Pseudoaneurysm Stent Placement

Acute pancreatitis (AP) is a relatively common condition most often secondary to excess alcohol consumption, choledocholithiasis, medications, or hypertriglyceridemia. In rare cases, AP can result in a secondary splenic artery pseudoaneurysm (SAP). SAPs are a rare yet serious medical complication and are often under-diagnosed as they are usually asymptomatic. However, rupture and subsequent hemorrhage of SAPs pose life-threatening risks. This case involves a 72-year-old male presenting with portal vein thrombosis and recurrent episodes of AP with persistently elevated levels of lipase of no apparent etiology over a 6-month period. As patient history and pertinent test results ruled out all common causes of recurrent AP, the etiology of his AP remained unknown. After an SAP rupture and emergency treatment with an endovascular stent, the patient's recurrent AP spontaneously resolved, and lipase returned to normal levels. This case represents a yet-to-be-reported etiology of AP in which the proximal nature of the SAP with its associated inflammatory response to the pancreas resulted in intermittent AP. The lack of any other reasonable explanation for the etiology of the patient's recurrent AP along with the absence of any additional episodes after the treatment of his SAP supports this diagnosis. The findings of this case could prove useful to clinicians with patients suffering from recurrent episodes of AP with no known etiology and suggest that a potential undiagnosed SAP should be investigated further.

Growing Renal Vein Aneurysm Treated by Endovascular Repair: A Case Report and Literature Review

Renal vein aneurysm (RVA) is extremely rare and often asymptomatic, disclosed only incidentally on diagnostic imaging modalities such as computed tomography and ultrasonography. Management is often just watchful follow-up, but some patients require intervention. We present the case of a 74-year-old man complaining of lower back pain in whom a 53-mm RVA was identified. He underwent successful endovascular repair using Amplatzer vascular plugs. The aneurysm had completely resolved by 12 months. Endovascular treatment of a primary RVA does not seem to have been reported previously. This is a milestone case in the management of RVA.

3D printing in the endovascular treatment of visceral artery aneurysms

Visceral artery aneurysms (VAAs) are vascular pathologies that are difficult to treat. The variable geometry of the vessels and the location of aneurysms render difficult their evaluation in radiological imaging studies. Less invasive endovascular procedures are increasingly used in common practice. Our aim was to test the feasibility of using 3D printing technology in the preparation of preoperative spatial models of visceral artery aneurysms and their impact on interventional treatment. In our observational study, we examined a group of patients with true aneurysms of the visceral arteries who were followed and who underwent endovascular procedures with the use of 3D prints for better imaging of vascular lesions. We analyzed the fused filament fabrication method of 3D printing and printable materials in the preparation of spatial vascular models. We confirmed that more accurate visualization and analysis of vascular anatomy could assist operators in attempting minimally invasive treatment with good results. Extending imaging studies using 3D printing models that allow for the assessment of the position, morphology and geometry of the aneurysm sac, particularly of vessel branches, could encourage surgeons to perform endovascular procedures.

Endovascular Treatment of Visceral Artery Pseudoaneurysms with Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs)

Background and Objectives: Treatment of visceral artery pseudoaneurysms (VAPs) is always indicated regardless of their diameters, as their risk of rupture is significantly higher than that of visceral artery aneurysms. The invasiveness of surgery and its associated complications have led to a shift in favor of radiological interventions as the initial treatment of choice. However, there are still some unanswered questions on endovascular treatment of VAPs regarding the optimal endovascular technique and the efficacy and safety outcomes. The purpose of this multicenter study was to retrospectively evaluate the effectiveness and safety of endovascular treatment of visceral pseudoaneurysms using Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs). Materials and Methods: Consecutive patients who underwent endovascular embolization with EVOH-based NALEAs for visceral artery pseudoaneurysms between January 2018 and June 2023 were retrospectively evaluated. Results: 38 embolizations were performed. Technical success was achieved in all patients. The clinical success rate was high (92.1% overall), with no significant differences between ruptured and unruptured VAPs (p = 0.679). Seven patients (18.4%) experienced procedure-related complications, related to one case of non-target embolization, four splenic abscesses due to end-organ infarction, and two femoral pseudoaneurysms. The rates of procedure-related complications, end-organ infarction, and vascular access-site complications did not significantly differ between ruptured and unruptured VAPs (p > 0.05). Conclusions: Both ruptured and unruptured visceral pseudoaneurysms can be effectively and safely treated with NALEA-based endovascular embolization. We suggest considering the use of NALEAs, particularly in specific clinical cases that highlight their advantages, including patients with coagulopathy, fragile vessels, and embolization targets that are located at a considerable distance from the microcatheter tip and are otherwise difficult to reach.

Emergent vessel embolization for major traumatic and non-traumatic hemorrhage: Indications, tools and outcomes

Endovascular embolization of bleeding vessels in trauma and non-trauma patients is frequently used and is an important tool for bleeding control. It is included in the EVTM (endovascular resuscitation and trauma management) concept and its use in patients with hemodynamic instability is increasing. When the correct embolization tool is chosen, a dedicated multidisciplinary team can rapidly and effectively achieve bleeding control. In this article, we will describe the current use and possibilities for embolization of major hemorrhage (traumatic and non-traumatic) and the published data supporting these techniques as part of the EVTM concept.

Acute management of mesenteric emergencies: Tailoring the solution to the problem

Acute mesenteric ischemia (AMI) constitutes a life-threatening problem that can result in death, multiorgan failure, and severe nutritional disability. Although AMI is a rare cause of acute abdominal emergencies, ranging between 1 and 2 individuals per 10,000, the morbidity and mortality rates are high. Arterial embolic etiology composes nearly one-half of AMIs, with a sudden onset of severe abdominal pain considered the most common symptom. Arterial thrombosis is the second most common cause of AMI, which presents similarly to arterial embolic AMI, although often more severe due to anatomic differences. Veno-occlusive causes of AMI are the third most common and are associated with an insidious onset of vague abdominal pain. Each patient is unique, and the treatment plan should be tailored to their individual needs. This may include considering the patient's age, comorbidities, and overall health, as well as their preferences and personal circumstances. A multidisciplinary approach involving specialists from different fields, such as surgeons, interventional radiologists, and intensivists, is recommended for the best possible outcome. Potential challenges in tailoring an optimal treatment plan for AMI may include delayed diagnosis, limited availability of specialized care, or patient factors that make some interventions less feasible. Addressing these challenges requires a proactive and collaborative approach, with regular review and adjustment of the treatment plan as needed to ensure the best possible outcome for each patient.

Pulmonary Artery Pseudoaneurysms Embolization: Bicentric Experience and Review of the Literature

The purpose of this bicentric case series was to report the safety, efficacy, and clinical outcome of transcatheter embolization in pulmonary artery pseudoaneurysms (PAPAs). Between January 2016 and June 2021, eight patients with PAPA were subjected to transcatheter embolization. The total number of patients was eight, of which five were female, with a mean age of 62 ± 14 years (average ± standard deviation). Etiology was traumatic in 2/8 cases and iatrogenic in 6/8 cases (after positioning a Swan-Ganz catheter in 5/6 cases and a temporary pacemaker in the latter case). In a single case, the PAPA was incidentally discovered during a routine X-ray, in the remaining 7 cases, the procedure was performed in emergency settings. PAPA embolization was performed using detachable coils alone in 3 cases; coils and glue in 1 case; coils, glue, and vascular plug in 1 case; coils and non-adhesive liquid embolic agents (Onyx and Squid respectively) in 2 cases; and non-adhesive liquid embolic agent alone (Onyx) in 1 case. No peri-procedural or post-procedural complications were recorded. Both the technical and clinical success rates were 100.0%. In conclusion, endovascular embolization is a technically feasible and safe therapeutic option for patients with PAPAs.

Giant Superior Mesenteric Artery Aneurysm Treated by Endovascular Treatment in a Very Elderly Female

Superior mesenteric artery (SMA) aneurysms (SMAAs) are rare and account for approximately 7% of all visceral artery aneurysms. If the anatomical complexity permits and the patency of organ perfusion is allowed, then an endovascular approach is the first choice for minimally invasive procedures. We report the case of a 92-year-old female with a giant SMAA and challenging anatomy, including a short proximal sealing zone from the origin of the SMA and a short distal sealing zone from the hepatic artery bifurcation. In view of her advanced age, she was treated endovascularly with covered stents. Reintervention was required to correct a postoperative endoleak; however, a favorable outcome was achieved with endovascular therapy.

Endovascular embolization of visceral artery aneurysm: a retrospective study

To assess the safety and efficacy of endovascular embolization techniques, we compared the short- to medium-term prognosis of coil embolization for symptomatic visceral aneurysms (SVAA) and asymptomatic visceral aneurysms (ASVAA) to identify risk factors associated with 30-day mortality. Explore the symptom profile and intrinsic associations of SVAA. A retrospective study of 66 consecutive patients at two tertiary care hospitals from 2010 to 2020 compared the short- to mid-term outcomes of 22 symptomatic VAAs and 44 asymptomatic VAAs treated with coil embolization. Univariate and log-rank tests were used to analyze the prognostic impact of SVAA and ASVAA. SVAA group had significantly higher 30-day mortality than ASVAA group (2(9.1%) vs 0, P = 0.042), both patients who died had symptomatic pseudoaneurysms. Perioperative complications such as end-organ ischemia (P = 0.293) and reintervention (P = 1) were similar in both groups. No difference in event-free survival was identified between the two groups (P = 0.900), but we found that the majority of pseudoaneurysms were SVAA (4/5) and that they had a much higher event rate than true aneurysms. In addition, dyslipidemia may be an influential factor in the development of VAA (P = 0.010). Coil embolization is a safe and effective method of treatment for VAA. Most pseudoaneurysms have symptoms such as abdominal pain and bleeding, and in view of their risk, more attention should be paid to symptomatic patients and the nature of the aneurysm should be determined as soon as possible to determine the next stage of treatment.

ENDOVASCULAR DIAGNOSTICS AND TREATMENT OF HEMORRHAGES IN MILITARY AND CIVILIAN PATIENTS FOLLOWING ABDOMINAL SURGERY

OBJECTIVE

The aim: The retrospective analysis of the angiographic picture and clinical results of endovascular treatment of patients with postoperative abdominal and gastrointestinal bleeding was carried out.

PATIENTS AND METHODS

Materials and methods: The results of 447 endovascular diagnostic and therapeutic interventions in 391 patients (46 military and 345 civilians) with postoperative bleeding performed from 2012 to 2022 were studied. According to computer tomography with contrast enhancement, the source of bleeding was identified in 216 (67.7%) cases.

RESULTS

Results: In 345 (88.2%) patients, it was possible to reliably identify the source of bleeding on angiography. In 46 (11.8%) patients with an unexplained source of bleeding, the target arterial pool was determined on the basis of localization, volume, and features of surgical intervention and considered as preventive interventions. A total of 447 endovascular hemostatic interventions were performed on 391 patients. A stent graft was installed in 27 patients, 420 embolization were performed in 364 patients. Thus, in 43 (11.0%) patients, embolization was performed repeatedly, in 12 cases - three times, in 1 case - four times. In 16 cases (15 cases of prophylactic embolization), endovascular hemostasis was ineffective and required subsequent surgical intervention.

CONCLUSION

Conclusions: Endovascular interventions are an effective method of diagnosis and treatment of postoperative abdominal bleeding. Prophylactic embolization allows you to prevent the recurrence of postoperative bleeding with an instrumentally undiagnosed source, however, you need to be prepared for the multi-stage treatment aimed at sequentially shutting down the collateral blood supply to the damaged area.

Massive upper gastrointestinal bleeding caused by splenic artery pseudoaneurysm rupture: A case report

BACKGROUND

Upper gastrointestinal (UGI) bleeding secondary to a ruptured splenic artery pseudoaneurysm (SAP) is a rare but life-threatening condition. Owing to the low prevalence, it remains a diagnostic and therapeutic challenge. When patients are admitted to the hospital with UGI bleeding, it is easy to overlook the cause of SAP rupture.

CASE SUMMARY

We report the case of a 65-year-old man who was admitted to our hospital with hematemesis. By endoscopic inspection and imaging examination, he was diagnosed with a ruptured SAP that caused UGI bleeding. He underwent surgery and was discharged 20 d after surgery. Now, he has good quality of life, with no incidents of hematemesis or melena.

CONCLUSION

We have documented a case of SAP rupture of unknown etiology, in which the ruptured SAP caused a gastric fistula that eventually resulted in massive UGI bleeding. Through timely diagnosis and treatment, the patient's life was saved. Therefore, even if patients with acute UGI bleeding have no previous history of pancreatic disease, abdominal trauma, etc., it is still suggested that SAP be considered as a differential diagnosis. Once SAP is found, a prompt diagnosis and urgent treatment strategy should be employed to achieve good results.

Embolization in Pediatric Patients: A Comprehensive Review of Indications, Procedures, and Clinical Outcomes

Embolization in pediatric patients encompasses a large spectrum of indications, ranging from the elective treatment of congenital diseases of the cardiovascular system to the urgent management of acute hemorrhagic conditions. In particular, the endovascular treatment of central and peripheral vascular malformations and hypervascular tumors represents a wide chapter for both congenital and acquired situations. Thanks to the progressive availability of low-profile endovascular devices and new embolic materials, the mini-invasive approach has gradually overtaken surgery. In this review, the main embolization procedures will be illustrated and discussed, with a focus on clinical indications and expected outcomes. The most recent mini-invasive techniques will be described, with hints on the cutting-edge devices and embolic materials.

Placement of a flow diverter-like stent together with coil embolisation for treatment of pancreatic pseudoaneurysm involving the origin of the gastroduodenal artery

A pancreatic pseudoaneurysm can occur following an attack of pancreatitis. This occurs due to erosion of the pancreatic or peripancreatic artery by the pancreatic enzyme-rich pancreatic secretion pseudocyst. If left untreated, it may cause massive and even fatal haemorrhage. Interventional radiology with coil embolisation of the pseudoaneurysm is the standard of care in such cases. We describe a patient who developed a pseudoaneurysm involving the origin of the gastroduodenal artery (GDA). This was successfully managed by coil embolisation of the pseudoaneurysm along with placement of a flow diverter-like stent in the common hepatic artery across the origin of the GDA leading to exclusion of the diseased segment.

Splenic Artery Pseudoaneurysms: The Role of ce-CT for Diagnosis and Treatment Planning

Splenic artery pseudoaneurysm (PSA) is a contained vascular wall lesion associated with a high mortality rate, generally related to pancreatitis, trauma, malignancy, iatrogenic injury, and segmental arterial mediolysis. Computed tomography angiography allows us to visualize the vascular anatomy, differentiate a PSA from an aneurysm, and provide adequate information for endovascular/surgical treatment. The present review reports on the main state-of-the-art splenic artery PSA diagnosis, differentiating between the pros and cons of the imaging methods and about the endovascular treatment.

Non-Adhesive Liquid Embolic Agents in Extra-Cranial District: State of the Art and Review of the Literature

This review focuses on the use of “new” generation of non-adhesive liquid embolic agents (NALEA). In literature, non-adhesive liquid embolic agents have mainly been used in the cerebral district; however, multiple papers describing the use of NALEA in the extracranial district have been published recently and the aim of this review is to explore and analyze this field of application. There are a few NALEA liquids such as Onyx, Squid, and Phil currently available in the market, and they are used in the following applications: mainly arteriovenous malformations, endoleaks, visceral aneurysm or pseudoaneurysm, presurgical and hypervascular lesions embolization, and a niche of percutaneous approaches. These types of embolizing fluids can be used alone or in combination with other embolizing agents (such as coils or particles) so as to enhance its embolizing effect or improve its possible defects. The primary purpose of this paper is to evaluate the use of NALEAs, predominantly used alone, in elective embolization procedures. We did not attempt a meta-analysis due to the data heterogeneity, high number of case reports, and the lack of a consistent follow-up time period.