Selective arterial embolization with ethylene-vinyl alcohol copolymer for control of massive lower gastrointestinal bleeding: feasibility and initial experience. J Vasc Interv Radiol. 2014;25:839-846. [PMID: 24755085 DOI: 10.1016/j.jvir.2014.02.024]

Twenty years of embolization for acute lower gastrointestinal bleeding: a meta-analysis of rebleeding and ischaemia rates

BACKGROUND

Transarterial embolization (TAE) for acute lower gastrointestinal bleeding (LGIB) can be technically challenging due to the compromise between achieving haemostasis and causing tissue ischaemia. The goal of the present study is to determine its technical success, rebleeding, and post-embolization ischaemia rates through meta-analysis of published literature in the last twenty years.

METHODS

PubMed, Embase, and Cochrane Library databases were queried. Technical success, rebleeding, and ischaemia rates were extracted. Baseline characteristics such as author, publication year, region, study design, embolization material, percentage of superselective embolization were retrieved. Subgroup analysis was performed based on publication time and embolization agent.

RESULTS

A total of 66 studies including 2121 patients who underwent embolization for acute LGIB were included. Endoscopic management was attempted in 34.5%. The pooled overall technical success, rebleeding, post-embolization ischaemia rates were 97.0%, 20.7%, and 7.5%, respectively. Studies published after 2010 showed higher technical success rates (97.8% vs 95.2%), lower rebleeding rates (18.6% vs 23.4%), and lower ischaemia rates (7.3% vs 9.7%). Compared to microcoils, NBCA was associated with a lower rebleeding rate (9.3% vs 20.8%) at the expense of a higher post-embolization ischaemia rate (9.7% vs 4.0%). Coagulopathy (P = .034), inotropic use (P = .040), and malignancy (P = .002) were predictors of post-embolization rebleeding. Haemorrhagic shock (P < .001), inotropic use (P = .026), malignancy (P < .001), coagulopathy (P = .002), blood transfusion (P < .001), and enteritis (P = .023) were predictors of mortality. Empiric embolization achieved a similarly durable haemostasis rate compared to targeted embolization (23.6% vs 21.1%) but a higher risk of post-embolization ischaemia (14.3% vs 4.7%).

CONCLUSION

For LGIB, TAE has a favourable technical success rate and low risk of post-embolization ischaemia. Its safety and efficacy profile has increased over the last decade. Compared to microcoils, NBCA seemed to offer a more durable haemostasis rate at the expense of higher ischaemia risk. Due to the heterogeneity of currently available evidence, future prospective and comparative studies are warranted.

ADVANCES IN KNOWLEDGE

(1) Acute LGIB embolization demonstrate a high technical success rate with acceptable rate of rebleeding and symptomatic ischaemia rates. Most ischaemic stigmata discovered during routine post-embolization colonoscopy were minor. (2) Although NBCA seemed to offer a more durable haemostasis rate, it was also associated with a higher risk of ischaemia compared to microcoils. (3) Coagulopathy, malignant aetiology, and inotropic use were predictors of rebleeding and mortality. (4) Routine post-embolization endoscopy to assess for ischaemia is not indicated.

Rare but critical: Aberrant vascular communication leading to multiorgan ischemia after prophylactic gastroduodenal artery embolization for refractory upper gastrointestinal bleeding

Upper gastrointestinal bleeding (UGIB) carries a high risk of morbidity and mortality despite recent improvements in diagnosis and management. Many patients failed to respond to initial endoscopic and medical management. Transcatheter arterial embolization (TAE) is now considered the next line of therapy over surgery in refractory UGIB because of its good safety profile and high technical and clinical success rate. We discuss the case of a 66-year-old female patient who presented with massive UGIB and had TAE after endoscopic hemostasis failed. She developed widespread ischemia involving multiple organs following the procedure, including the liver, gallbladder, pancreas, spleen, and small intestine, as a result of an abnormal communication between the gastroduodenal artery (GDA) and superior mesenteric artery (SMA), resulting in PVA particle reflux and widespread ischemic injury. It is important to carefully evaluate the vascular anatomic variations before the procedure to avoid potential complications of ischemia.

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.

Transcatheter Arterial Embolization (TAE) of Cancer-Related Bleeding

Background and Objectives: Roughly 10% of cancer patients experience an episode of bleeding. The bleeding severity can range from occasional trivial bleeds to major bleeding. The treatment for the bleeding may vary, depending on the clinical condition and anatomical site, and may include various strategies, among which TAE is a cornerstone of major bleeding management. However, the existing literature on tumor hemorrhages is inconsistent. The objective of this multicenter retrospective cohort study was to evaluate the effectiveness and safety of arterial embolization in the treatment of tumor hemorrhages in patients with solid cancers. Materials and Methods: The data for patients with solid cancers undergoing TAE for the management of tumor hemorrhages from January 2020 to May 2023 were gathered. Results: A total of 92 patients with cancer-related bleeding were treated between January 2020 and May 2023. No bleeding was detected by X-ray angiography (XA) in 12 (13%) cases; therefore, a blind embolization was performed. The most common bleeding site was the liver (21.7%). A total of 66 tumor hemorrhages were spontaneous. The most commonly used embolic agent was polyvinyl alcohol (PVA) particles (30.4%). Technical success was achieved in 82 (89.1%) cases, with an 84.8% clinical success rate related to 14 cases of rebleeding. Proximal embolization was performed for 19 (20.7%) patients. Complications were recorded for 10 (10.9%) patients. The 30-day bleeding-related mortality was 15.2%. The technical success, clinical success, proximal embolization rate, and 30-day rebleeding were worse in the subset of patients undergoing TAE with coils. Conclusions: Transcatheter arterial embolization (TAE) represents a viable and potentially life-saving therapeutic approach in the management of tumor hemorrhages, demonstrating a notable effectiveness and safety. The TAE of bleeding tumors using coils resulted in a higher rate of non-superselective proximal embolization, with a trend toward lower clinical success rates and higher rebleeding episodes.

Safety, Efficacy and Mid-Term Outcome for Transarterial Embolization (TAE) of Renal Angiomyolipoma (AML) Using Ethylene Vinyl Alcohol Copolymer Liquid Embolic Agent (EVOH)

Transarterial embolization (TAE) of renal angiomyolipoma (AML) is effective in treating and preventing hemorrhage. We report our experience using EVOH with a single-center retrospective study of all AML embolized with EVOH between June 2013 and March 2022 at the Montpellier University Hospital. A total of 29 embolizations were carried out in 24 consecutive patients (mean age: 53.86 years; 21 women and 3 men) with 25 AMLs for severe bleeding, symptomatic AML, tumor size > 4 cm, or presence of aneurysm(s) > 5 mm. Data collected included imaging and clinical outcomes, tuberous sclerosis complex status, change in AML volume, rebleeding, renal function, volume and concentration of EVOH used, and complications. Out of 29 embolizations performed for 25 AMLs, four were performed in an emergency. Technical success was achieved for 24/25 AMLs. Mean AML volume reduction was 53.59% after a mean follow-up time of 446 days using MRI or CT scan. Aneurysms on angiogram and the symptomatological nature of AML, as well as secondary TAE and multiple arterial pedicles, were statistically associated (p < 0.05). Two patients (8%) underwent nephrectomy after TAE. Four patients had a second embolization. Minor and major complication rates were 12% and 8%, respectively. Neither rebleeding nor renal function impairment was noticed. TAE of AML using EVOH is, thus, highly effective and safe.

Efficacy and Safety of Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs) in Transcatheter Arterial Embolization (TAE) of Acute Non-Neurovascular Bleeding: A Multicenter Retrospective Cohort Study

Background and Objectives: Transcatheter arterial embolization (TAE) is part of the daily practice of most interventional radiologists worldwide. The ideal liquid embolic agent is far from being identified. Non-adhesive liquid embolic agents (NALEA) harden from the outside to the inside, resulting in deep penetration, known as "magma-like" progression, which permits a more distal embolization with good control of the embolic material. This multicenter retrospective cohort study aims to assess the efficacy, feasibility and safety of transcatheter arterial embolization (TAE) with ethylene-vinyl alcohol (EVOH)-based NALEAs (Onyx and Squid) in acute bleeding outside of the neurovascular area. Materials and Methods: This study is a multicenter analysis of retrospectively collected data of consecutive patients who had undergone, from January 2015 to December 2022, transcatheter arterial embolization with non-adhesive EVOH-based agents in the setting of acute non-neurovascular bleeding. Results: Fifty-three patients underwent transcatheter arterial embolization for acute non-neurovascular bleeding. Eight (15.1%) procedures were performed in patients with coagulopathy. The most used concentration of EVOH-based NALEAs was 34 (i.e., 8%), with a mean dose of 0.5 (±0.3) mL. The mean CT-to-groin time, the mean procedure time, the mean CT-to-embolization time and the mean fluoroscopy time were 22.9 (±12.4) min, 27.5 (±7) min, 50.3 (±13.1) min and 7.5 (±2.8) min, respectively. Technical success was achieved in all cases with a 96.2% clinical success rate. Complications were recorded in six (11.3%) patients. No statistically significant differences were observed between the group of patients with coagulopathy and the group of patients without coagulopathy in terms of efficacy and safety endpoints. Conclusions: Transcatheter arterial embolization (TAE) performed with non-adhesive EVOH-based embolic agents is an effective, feasible and safe strategy for the management of acute non-neurovascular bleeding, even in the subgroup of patients with coagulopathy.

Transarterial embolization of acute non-neurologic bleeding using Ethylene Vynil Alcohol Copolymer: a single-Centre retrospective study

BACKGROUND

To evaluate feasibility, safety and effectiveness of transarterial embolization of acute non-neurologic hemorrhage with Ethylene Vynil Alcohol Copolymer (EVOH).

METHODS

Between January 2018 and June 2021, 211 patients (male 123, mean age 69.7 y + 17.9) who underwent transarterial embolization with Onyx™ for acute non-neurologic arterial bleeding were retrospectively reviewed. Most frequent etiology of bleeding was post-operative (89/211, 42.2%), trauma (62/211, 29.4%) and tumor (18/211, 8.5%). Technical success was defined as the angiographic evidence of target vessel complete occlusion. Clinical success was defined as resolution of bleeding. Any rebleeding within the primitive site, requiring a new intervention during the first 30-days following embolization, was considered a clinical failure. Occurrence of procedure-related complication and mortality within 30 days of the embolization were examined.

RESULTS

A total of 229 embolization procedures was performed in 211 pts.; technical success rate was 99.5% (210/211 pts). Clinical success rate was 94.3% (199/211 pts). In 11 patients (5.2%) a reintervention was needed because of a rebleeding occurring within the primitive site, whereas in five patients (2.4%) rebleeding occurred within a site different from the primitive. Factors more often associated with clinical failure were coagulopathy/ongoing anticoagulant therapy (5/11, 45.4%), and post-operative etiology (3/11, 27.3%). EVOH was used as the sole embolic agent in 214/229 procedures (93.4%), in association with coils in 11 cases (4.8%), and with microparticles in 4 cases (1.7%). In the present series, major complications occurred in 6 cases (2.8%): respectively, four cases (1.9%) of colonic ischemia and two groin hematomas (0.9%) with active extravasation were observed. 26 (12.3%) patients died during the follow-up.

CONCLUSION

Embolization of acute arterial bleeding with EVOH as a first-line embolic agent is feasible, safe and effective.

Indian College of Radiology and Imaging Consensus Guidelines on Interventions in Pancreatitis

Acute pancreatitis (AP) is one of the common gastrointestinal conditions presenting as medical emergency. Clinically, the severity of AP ranges from mild to severe. Mild AP has a favorable outcome. Patients with moderately severe and severe AP, on the other hand, require hospitalization and considerable utilization of health care resources. These patients require a multidisciplinary management. Pancreatic fluid collections (PFCs) and arterial bleeding are the most important local complications of pancreatitis. PFCs may require drainage when infected or symptomatic. PFCs are drained endoscopically or percutaneously, based on the timing and the location of collection. Both the techniques are complementary, and many patients may undergo dual modality treatment. Percutaneous catheter drainage (PCD) remains the most extensively utilized method for drainage in patients with AP and necrotic PFCs. Besides being effective as a standalone treatment in a significant proportion of these patients, PCD also provides an access for percutaneous endoscopic necrosectomy and minimally invasive necrosectomy. Endovascular embolization is the mainstay of management of arterial complications in patients with AP and chronic pancreatitis. The purpose of the present guideline is to provide evidence-based recommendations for the percutaneous management of complications of pancreatitis.

Endovascular Treatment of Gastrointestinal Hemorrhage

Background and Objectives: Severe non-variceal gastrointestinal bleeding is a life-threatening condition with complicated treatment if endoscopic therapy fails. In such cases, transcatheter arterial embolization is recommended. The technical and clinical effects of this technique were analyzed in this group of patients, as well as its complication rate and 30-day mortality. Materials and Methods: Patient data over a one-decade period (from 2010 to 2019) were analyzed retrospectively; 27 patients (18 men and 9 women; median age 61 years) treated by endovascular embolization in our institution, with clinically significant gastrointestinal hemorrhage after unsuccessful or impossible endoscopic treatment, were identified, and their data were collected. Results: The source of bleeding was found in 88% of patients, but embolization was performed in 96% of them. The overall technical success rate was 96.8%, and the clinical success was 88.5%. Re-bleeding occurred in eight cases, five of whom had re-embolization that was technically successful in four cases. The incidence of re-bleeding was significantly higher in patients with two or more comorbidities (p = 0.043). There was one serious complication (4%) in the group, and minor difficulties occurred in 18% of patients; 30-day mortality reached 22%. Mortality was significantly higher in the group of patients with re-bleeding (p = 0.044). Conclusions: Transcatheter arterial embolization is a mini-invasive method with high technical success in patients with endoscopically untreatable gastrointestinal bleeding; it is also suitable for high-risk cases. Mortality (to a significant extent) depends on the occurrence of re-bleeding and the patient’s comorbidities.

Evaluation of Multiple Embolic Agents for Embolization of the Superior Rectal Artery in an Animal Model

OBJECTIVE

To prospectively compare the safety of transcatheter embolization of superior rectal arteries in healthy pigs with multiple agents such as coils, spheres and liquids.

MATERIALS AND METHODS

Nine adult domestic pigs (three males, mean weight: 60 kg [50-70]) were randomly assigned to the embolization group: copolymer of ethylene vinyl alcohol (EVOH)-Onyx® (group 1, n = 3), microspheres 500 µ (group 2, n = 3), 2-mm micro-coils (group 3, n = 3). After a selective angiogram has been acquired, the embolic agent was infused at the distal part of rectal arteries. An angio-CT was performed before and after each embolization. After one week, angiography was repeated prior to euthanasia. At necropsy, the anorectal juncture was removed for histopathologic examination.

RESULTS

At necropsy, 100% of animals embolized with Onyx developed a significant necrosis zone of the distal part of the rectum. Histological examination revealed a mural infarction. For the micro-coil and microsphere groups, gross examination of the intestines did not reveal any evidence of ischaemia. The coils were found in the distal arterial vasculature of the meso-rectum, allowing a downstream revascularization by collaterals. The microspheres and onyx in the rectal wall, more distally.

CONCLUSION

Microspheres appear to induce fewer histologic complications than the liquid embolic agent and provide a more distal occlusion than micro-coils. These results suggest that, for superior rectal artery embolization, a super-selective embolization using spheres in human clinical conditions should be more effective and as safe as coil embolization. EVOH might be an unsafe embolization agent for haemorrhoids.

Embolic Materials: Understanding the Ocean of Choices

Embolization is a fundamental procedure that interventional radiologists perform on a daily basis to treat a variety of diseases. The disease processes for which embolization is considered a safe and effective treatment are continuously expanding, as are the embolization materials available for use. To achieve optimal clinical outcomes and minimize complications, it is imperative that the interventional radiologist understands the properties, strengths, and weaknesses of each class of embolic and specific embolic products. This is a continuous process as new materials are always becoming available. This article reviews the different classes of embolic materials, discusses strengths and weaknesses, and reviews areas of innovation.

Transcatheter Arterial Embolization in Acute Non-Variceal Gastrointestinal Bleedings: A Ten-Year Single-Center Experience in 91 Patients and Review of the Literature

Objective: To report the safety and efficacy of trans-arterial embolization (TAE) for upper gastrointestinal bleeding (UGIB) and lower gastrointestinal bleeding (LGIB) due to different etiologies in 91 patients for ten years. Methods: A retrospective analysis of GIB treated between January 2010 and December 2020 was performed. TAE was performed using different embolic agents (coils, particles, glue, gelatin sponge, and EVOH-based agents). Technical success, secondary technical success, clinical success, and complications were evaluated. Results: Technical success was achieved in 74/91 (81.32%) patients. Seventeen patients (18.68%) required re-intervention. Secondary technical success was achieved in all cases (100.0%). Clinical success was achieved in 81/91 patients (89.01%). No major complications were recorded; overall, minor complications occurred in 20/91 patients. Conclusions: TAE is a technically feasible and safe therapeutic option for patients with GIB from a known or blind anatomic source where endoscopic therapy has failed or is deemed unfeasible.

Small bowel obstruction caused by secondary jejunal tumor from renal cell carcinoma: A case report

BACKGROUND

Secondary jejunal tumor from renal cell carcinoma (RCC) is extremely rare in clinical practice and is easily missed and misdiagnosed because of the low incidence and atypical symptoms.

CASE SUMMARY

A 38-year-old male patient was diagnosed pathologically with left RCC after radical nephrectomy in 2012. The patient then suffered multiple lung metastases 2 years later and was treated with oral sorafenib without progression for 6 years. In 2020, an emergency intestinal segmental resection due to intestinal obstruction was required, and postoperative pathology confirmed a jejunal secondary tumor from RCC. The patient had a smooth recovery following surgery. Three months after surgery, the patient was diagnosed with left adrenal metastasis, and subsequent sintilimab therapy has stabilized his condition.

CONCLUSION

This report is written to remind urologists and pathologists of the potential for small intestinal secondary tumors when a patient with a history of RCC seeks treatment for digestive symptoms. Enteroscopy and abdominal contrast-enhanced computed tomography are essential means of examination, but severe cases require immediate surgical intervention despite the lack of a preoperative examination to distinguish tumor attributes.

Acute limb ischemia due to ONYX 34 migration during embolization of a traumatic pseudoaneurysm of the superficial femoral artery

Pseudo-aneurysms of the arteries of the lower limbs are a possible complication of leg trauma. Complications include rupture, infection, pain and distal embolization. This is a case of a 24-year-old man hospitalized after a car accident, in which we discovered a 1-cm large pseudo-aneurysm of the right superficial femoral artery. The pseudo-aneurysm in first place was treated by the interventional-radiologist for an endovascular repair by embolization with ONYX 34, but during the procedure the copolymer embolized in the arterial axe with complete obstruction of blood-flow in the lower limb. An urgent open surgical revascularization was then attempted by our team with the result of complete patency of the femoro-popliteal axis and of the tibial vessels. Embolization with ONYX is an effective and safe method, but it is susceptible to this type of complication for larger pseudo-aneurysms, where it is required an introduction of a larger quantity of polymer.

ACR Appropriateness Criteria® Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update

Diverticulosis remains the commonest cause for acute lower gastrointestinal tract bleeding (GIB). Conservative management is initially sufficient for most patients, followed by elective diagnostic tests. However, if acute lower GIB persists, it can be investigated with colonoscopy, CT angiography (CTA), or red blood cell (RBC) scan. Colonoscopy can identify the site and cause of bleeding and provide effective treatment. CTA is a noninvasive diagnostic tool that is better tolerated by patients, can identify actively bleeding site or a potential bleeding lesion in vast majority of patients. RBC scan can identify intermittent bleeding, and with single-photon emission computed tomography, can more accurately localize it to a small segment of bowel. If patients are hemodynamically unstable, CTA and transcatheter arteriography/embolization can be performed. Colonoscopy can also be considered in these patients if rapid bowel preparation is feasible. Transcatheter arteriography has a low rate of major complications; however, targeted transcatheter embolization is only feasible if extravasation is seen, which is more likely in hemodynamically unstable patients. If bleeding site has been previously localized but the intervention by colonoscopy and transcatheter embolization have failed to achieve hemostasis, surgery may be required. Among patients with obscure (nonlocalized) recurrent bleeding, capsule endoscopy and CT enterography can be considered to identify culprit mucosal lesion(s). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Cost-Effectiveness Analysis of Transcatheter Arterial Embolization Techniques for the Treatment of Gastrointestinal Bleeding in the United States

OBJECTIVES

Gastrointestinal (GI) bleeding is a common medical emergency associated with significant mortality. Transcatheter arterial embolization first was introduced by Rosch et al as an alternative to surgery for upper GI bleeding. The clinical success in patients with GI bleeding treated with transcatheter arterial embolization previously has been reported. However, there are no cost-effectiveness analyses reported to date. Here we report cost-effectiveness analysis of N-butyl 2-cyanoacrylate glue (NBCA) and ethylene-vinyl alcohol copolymer (Onyx) versus coil (gold standard) for treatment of GI bleeding from a healthcare payer perspective.

METHODS

Fixed-effects modeling with a generalized linear mixed method was used in NBCA and coil intervention arms to determine the pooled probabilities of clinical success and mortality with complications with their confidence intervals, while the Clopper-Pearson model was used for Onyx to determine the same parameters. Models were provided by the "Meta-Analysis with R" software package. A decision tree was built for cost-effectiveness analysis, and Microsoft Excel was used for probabilistic sensitivity analysis. The cost-effective option was determined based on the incremental cost-effectiveness ratio and scatter plots of incremental cost versus incremental quality-adjusted life-years.

RESULTS

Comparing scatter plots and incremental cost-effectiveness ratio results, -$1024 and -$1349 per quality-adjusted life-year for Onyx and N-butyl 2-cyanoacrylate glue, respectively, Onyx was the least expensive and most effective intervention.

CONCLUSION

Onyx was the dominant strategy regardless of threshold values. Our analyses provide a framework for researchers to predict the target clinical effectiveness for early-stage TAE interventions and guide resource allocation decisions.

Assessment of the embolization effect of temperature-sensitive p(N-isopropylacrylamide-co-butyl methylacrylate) nanogels in the rabbit renal artery by CT perfusion and confirmed by macroscopic examination

Transcatheter embolization is an important treatment method in clinical therapy, and vascular embolization material plays a key role in embolization. The temperature-sensitive p(N-isopropylacrylamide-co-butyl methylacrylate) (PIB) nanogel is a novel embolic agent. To evaluate the feasibility of the nanogel as a blood vessel embolization agent, we aimed to assess the effect of embolization with PIB nanogels in the rabbit renal artery by non-invasive computed tomography (CT) perfusion, macroscopic and histological examination. Ten healthy adult Japanese rabbits were used to implement RAE of PIB nanogels in their right kidneys. CT perfusion scans were performed pre- and post-treatment at various time-points (1, 4, 8, and 12 weeks). Two rabbits were euthanized and histologically examined at each time-point, and the remaining rabbits were euthanized at 12 weeks after embolization. The RAE efficacy of the nanogels was further confirmed by macroscopic and histological examination. The renal volume and renal blood flow (BF) of the right kidney were significantly decreased post-treatment compared with those pre-treatment (volume: pre, 9278 ± 1736 mm³; post 1 week, 5155 ± 979 mm³, P < 0.0001; post 4 weeks, 3952 ± 846 mm³, P < 0.0001; post 8 weeks, 3226 ± 556 mm³, P < 0.0001; post 12 weeks, 2064 ± 507 mm³, P < 0.0001. BF: pre, 530.81 ± 51.50 ml/min/100 ml; post 1 week, 0 ml/min/100 ml, P < 0.0001; post 4 weeks, 0 ml/min/100 ml, P < 0.0001; post 8 weeks, 0 ml/min/100 ml, P < 0.0001; post 12 weeks, 0 ml/min/100 ml, P < 0.0001). No revascularization or collateral circulation was observed on histological examination during this period, and PIB nanogels were dispersed in all levels of the renal arteries. Twelve weeks after embolization, CT perfusion showed no BF in the right renal artery and renal tissue, a finding that was consistent with histological examination showing complete embolization of the right renal artery with a lack of formation of collateral vessels. The effect of embolization on PIB was adequate, with good dispersion and permanency, and could be evaluated by non-invasive and quantitative CT perfusion.

Use of Phil Embolic Agent for Bleeding in Non-Neurological Interventions

Objective: To evaluate the safety and efficacy of the Phil liquid embolic agent in non-neurological embolization procedures. M&M: Thirty-five patients with a mean age of 62.5 years underwent percutaneous embolization using Phil for the treatment of visceral arterial bleedings in 20/35 patients (including three gluteal, one bladder, two superior mesenteric, three epigastric, one deep femoral, five internal iliac, four intercostal, and one lingual arteries), splanchnic pseudoaneurysms in 11/35 patients (including three hepatic, five splenic, and three renal arteries), pancreatic bleeding metastasis in 1/35 patient, and gastric bleeding varices in 3/35 patients. Phil is composed of a non-adhesive copolymer dissolved in DMSO (Anhydrous Dimethyl Sulfoxide) with different viscosity. Procedures were performed slowly under continuous fluoroscopic guidance to avoid embolization of non-target vessels. Results: Clinical success was obtained with a single intervention in 34 cases (97.15%), while a repeated procedure was required in one case (2.85%). No technical complications nor non-target embolization occurred. A case of post-embolic syndrome was noted (2.85%) in one patient. DMSO administration-related pain was successfully controlled by medical therapy. Conclusion: Phil can be considered a safe and effective embolic agent for the treatment of non-neurologic bleeding.

Recurrent massive hemoptysis in a patient with cystic fibrosis: balloon assisted Onyx embolization after bronchial artery coil recanalization

Background

Although not standard of care, Cystic Fibrosis patients with recurrent hemoptysis occasionally have coil embolization of bronchial arteries. In the event of recanalization of these arteries in this specific subset of patients, the presence of indwelling coils makes the prospect of conventional particle embolization more difficult, preventing both adequate catheterization of the coiled segment and reflux of the particles.

Case presentation

In this report, we describe a case of bronchial artery embolization of a complex Cystic Fibrosis patient with massive hemoptysis from recanalized coiled bronchial arteries utilizing a Scepter Balloon Catheter® (Microvention Terumo, USA) in administration of the liquid embolic agent Onyx® (Medtronic, USA).

Conclusions

The Scepter occlusion balloon catheter allowed for careful placement of the tip within the interstices of the pre-existing coils, allowing for Onyx injection directly into the coil mass without reflux, reconfirming the benefits of Onyx embolization in bronchial artery embolization and providing evidence that the Scepter occlusion balloon catheter should be added to the armamentarium of devices used in complex bronchial artery embolization for Cystic Fibrosis patients with massive hemoptysis.

Current role of cyanoacrylate glue transcatheter embolization in the treatment of acute nonvariceal gastrointestinal bleeding

INTRODUCTION

Over the past three decades, transcatheter arterial embolization (TAE) has become the first-line therapy for the management of acute nonvariceal gastrointestinal bleeding (NVGIB) that is refractory to endoscopic hemostasis. Advances in catheter-based techniques and newer liquid embolic agents, as well as recognition of the effectiveness of minimally invasive treatment options, have expanded the role of interventional radiology in the treatment of acute NVGIB. Many embolic agents have been used successfully. However, no guidelines exist about the choice of the best embolic agent which is still controversial. Cyanoacrylate glue has gained acceptance over time. This article aims to address the current role of TAE using cyanoacrylate glue for the treatment of acute NVGIB.

AREAS COVERED

The authors undertook a literature review of the current evidence on the use of cyanoacrylate glue in treating patients with acute NVGIB.

EXPERT OPINION

The evidence shows that cyanoacrylate glue is the most clinically useful embolic agent in treating patients with acute NVGIB, despite the need for learning curve, especially in case of coagulopathy. At present, research is ongoing to assess liquid embolic agents in the treatment of patients presenting with acute NVGIB. More research is needed but cyanoacrylate glue show promise for the future.

Single institutional experience of peripheral applications of a liquid embolic agent: Ethylene Vinyl Alcohol Copolymer

OBJECTIVE

To evaluate the safety and efficacy of ethylene vinyl alcohol (EVOH) copolymer for the treatment of a variety of peripheral vascular pathologies.

RESULTS

Between October 2010 and October 2017, 43 patients who underwent total 54 EVOH embolization procedures for the treatment of peripheral vascular pathologies were included. The cases which involved the use of EVOH for the treatment of nonvascular, neurologic, ophthalmologic, otolaryngologic or head-neck pathologies were excluded. The demographic data, technical and clinical success rates, and procedure-related details and complications were obtained. The most common indications for EVOH embolization were type II endoleaks (n = 18) and peripheral arteriovenous malformations (n = 14). The majority of cases (62.5%) used EVOH without any adjunct embolic material. The results of this study showed 100% technical success rates and 89% clinical success rates. No events of nontarget embolization or other procedure-related complications were noted. The mortality & morbidity rates were 0%. The loss to follow up rate was 16% (9 /54). The mean follow-up period was 134 days (range, 30 to 522 days).

CONCLUSION

The single institutional experience supports the safety and efficacy of EVOH embolization in the treatment of various peripheral vascular conditions.

Basic embolization techniques: tips and tricks

Good knowledge of the various approaches of embolization of peripheral bleedings and different embolic materials available is of paramount importance for successful and safe embolization. We review and illustrate the main endovascular and percutaneous techniques used for embolization, along with the characteristics of the different embolic materials, and the potential complications.

Pseudoaneurysm: a rare complication of distal transradial access in the anatomical snuffbox

BACKGROUND

This report presents a case of distal radial artery pseudoaneurysm following cardiac catheterization and its successful endovascular management. Due to its novelty as a catheterization site, few to no reports exist regarding the complications associated with distal radial access.

CASE PRESENTATION

A patient presented to the emergency department with severe wrist and hand swelling 48 h after successful cardiac catheterization via distal radial artery access. Angiography revealed a pseudoaneurysm which was embolized with Onyx™. Post intervention angiogram showed exclusion of the pseudoaneurysm and preservation of the left palmar arch vasculature.

CONCLUSION

The case presented herein demonstrates a rare complication of distal radial access at the anatomical snuffbox.

Migration of Ethylene Vinyl Alcohol Co-Polymer in the Urinary Tract Successfully Managed

Selective embolization is the treatment of choice for traumatic renal pseudoaneurysm. The use of ethylene vinyl alcohol copolymer (EVOH) was recently described as an embolic agent in peripheral lesions. The aim of a good embolic agent is to: achieve rapid and effective embolization; reach and fill distal vasculature targeted for embolization; be easy to prepare and use. Moreover, it should be highly radiopaque, controllable during administration, biocompatible and cost-effective. EVOH is a non-adhesive embolic agent and its efficacy is independent from the coagulant status. The risk of non-targeted embolization should be reduced by the good radio-opacity of the embolic material that is injected under continuous fluoroscopy. Nevertheless, symptomatic EVOH migration was described. We report a unique case of embolization of a renal pseudoaneurysm and migration of EVOH in the urinary tract. Retrograde trans-urethral removal of the migrated embolic agent was successfully performed. Our case report indicates that EVOH may not be appropriate when a fistula with renal calyx is suspected, even if its migration in the urinary tract may be managed.

When all else fails - Radiological management of severe gastrointestinal bleeding

Although most cases of acute nonvariceal gastrointestinal bleeding (GIB) either spontaneously resolve or respond to medical management and endoscopic therapy, there are still a significant proportion of severe patients who require emergency angiography and endovascular treatment. Over the past three decades, transcatheter arterial embolization (TAE) has become the first-line therapy for the management of acute nonvariceal GIB that is refractory to endoscopic hemostasis. Advances in catheter-based techniques and newer liquid embolic agents, as well as recognition of the effectiveness of minimally invasive treatment options, have expanded the role of interventional radiology in the treatment of bleeding for a variety of indications. TAE is a safe and effective minimally invasive alternative to surgery, when endoscopic treatment fails to control acute bleeding from the gastrointestinal tract. In this article we review the current role of angiography and TAE in the management of acute nonvariceal GIB.

The Role of Transcatheter Arterial Embolization in the Management of Nonvariceal Upper Gastrointestinal Bleeding

Nearly 50 years ago, catheter angiography was introduced as a means of both diagnosing and treating nonvariceal upper gastrointestinal bleeding. Technological advances and innovations have resulted in the introduction of microcatheters that, using a coaxial technique, are capable of selecting third-order arterial branches and of delivering a wide array of embolic agents. This article reviews the imaging diagnosis of nonvariceal upper gastrointestinal bleeding, the techniques of diagnostic and therapeutic angiography, the angiographic appearance of the various etiologies of nonvariceal upper gastrointestinal bleeding, the rationale behind case-specific selection of embolic agents as well as the anticipated outcome of transcatheter arterial embolization.

Transcatheter arterial embolisation for acute lower gastrointestinal haemorrhage: a single-centre study

OBJECTIVE

To investigate the safety and efficacy of transcatheter arterial embolisation (TAE) in the management of lower gastrointestinal bleeding (LGIB) and to identify predictors of clinical outcomes.

METHODS

Between December 2005 and April 2017, 274 patients underwent diagnostic angiography for signs and symptoms of LGIB; 134 patients with positive angiographic findings were retrospectively analysed. The technical success of TAE and clinical outcomes, including recurrent bleeding, major complications, and in-hospital mortality were evaluated. The associations of various clinical and technical factors with clinical outcomes were analysed. Predictors for clinical outcomes were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

A total of 134 patients (mean age, 59.7 years; range, 14-82 years) underwent TAE for LGIB. The bleeding foci were in the small bowel in 74 patients (55.2%), colon in 35 (26.1%), and rectum in 25 (18.7%). Technical success was achieved in 127 patients (94.8%). The clinical success rate was 63% (80/127). The rates of recurrent bleeding, major complications, and in-hospital mortality were 27.9% (31/111), 18.5% (23/124), and 23.6% (33/127), respectively. Superselective embolisation and the use of N-butyl cyanoacrylate (NBCA) were significant prognostic factors associated with reduced recurrent bleeding (OR, 0.258; p = 0.004 for superselective embolisation, OR, 0.313; p = 0.01 for NBCA) and fewer major complications (OR, 0.087; p ˂ 0.001 for superselective embolisation, OR, 0.272; p = 0.007 for NBCA).

CONCLUSIONS

TAE is an effective treatment modality for LGIB. Superselective embolisation is essential to reduce recurrent bleeding and avoid major complications. NBCA appears to be a preferred embolic agent.

KEY POINTS

• Transcatheter arterial Embolisation (TAE) is a safe and effective treatment for lower gastrointestinal tract haemorrhage. • Superselective embolisation is essential to improve outcomes. • N-butyl cyanoacrylate (NBCA) appears to be a preferred embolic agent with better clinical outcomes.

Trans Arterial Embolization of Non-variceal Upper Gastrointestinal Bleeding: Is the Use of Ethylene-Vinyl Alcohol Copolymer as Safe as Coils?

PURPOSE

The safety of liquid embolics over the conventional coils for the treatment of non-variceal upper gastrointestinal bleeding (UGIB) approach is still unclear. Purpose of this study is to assess the safety of ethylene-vinyl alcohol copolymer (EVOH 6%) over coils in the treatment of UGIB.

MATERIALS AND METHODS

All the upper gastrointestinal tract embolization procedures performed in a single center in a 6-year period were reviewed. Patients embolised with coils (Group A) versus those embolised with EVOH 6% (Group B) were compared. Technical/clinical success, bleeding recurrence, complication and mortality rates were analyzed.

RESULTS

A total 71 patients were included in the study (41 Group A and 30 Group B). Coagulopathy was present in 21% of Group A and 46% of Group B patients (p < 0.05). Technical and clinical success was 97.6 and 92.7% for Group A, and 100 and 93.3% for Group B respectively, (p > 0.05). Ten patients (17% Group A; 10% Group B) re-bled within the first 36 h and all of them were re-treated successfully with a second embolization. In Group A one major complication (bowel ischemia) occurred. No complication occurred in Group B. The survival rate in the first 30 days was 90.3% for group A and 90% for group B (p > 0.05).

CONCLUSION

This study demonstrated EVOH 6% appears to be as safe and effective as coils in the treatment of non-variceal UGIB.

Embolization with ethylene vinyl alcohol copolymer (Onyx®) for peripheral hemostatic and non-hemostatic applications: a feasibility and safety study

Background

Onyx^® is a liquid embolic agent, which is approved for the treatment of cerebral vascular lesions but still rarely used in peripheral interventional radiology. The goal of this study is to report the feasibility and safety of embolization with Onyx^® for peripheral hemostatic and non-hemostatic endovascular procedures.

Methods

Retrospective study of all consecutive patients who underwent visceral or peripheral embolization with Onyx^® for hemostatic or non-hemostatic purpose in our department between May 2014 and November 2016. Demographic data, clinical presentation, underlying etiology, culprit vessel, endovascular procedure, pain during embolization, outcomes, and follow-up data were collected.

Results

Fifty patients (males, 34; females, 16; mean age, 56±18 years; range, 15-89 years) were included. Twenty-nine (58%) of patients underwent hemostatic embolization for arterial (n=22, 44%) or venous (n=7, 14%) bleeding lesions, whereas 21 (42%) of patients underwent non-hemostatic embolization for arterial aneurysms (n=8, 16%), preoperative portal vein deprivation (n=6, 12%) or other indications (n=7, 14%). Onyx-18 was used in 37 (74%) patients, Onyx-34 in 9 (18%) patients, and a combination of both in 4 (8%) patients. Onyx was used alone in 25 (50%) patients and in combination with other agent in 25 (50%) patients. Mean number of Onyx^® vials used was 3.7 (range, 1-17). Immediate technical success rate was 100%. Primary clinical success was achieved in all patients. Recurrent bleeding occurred in two patients. Significant pain (pain score ≥3) was noted during injection in 10 (20%) patients. No major complication or side effects were noted within 1 month.

Conclusions

Transcatheter embolization with Onyx^® is feasible and safe in the peripheral arterial or venous vasculature for both bleeding and non-bleeding patients whatever the anatomic site.

Transcatheter arterial embolization for upper gastrointestinal tract bleeding

Introduction

Transcatheter arterial embolization is a possible treatment for patients with recurrent bleeding from the upper gastrointestinal tract after failed endoscopic management and is also an alternative to surgical treatment.

Aim

To analyze the outcomes of transcatheter arterial embolization and identify the clinical and technical factors that influenced the rates of morbidity and mortality.

Material and methods

A retrospective analysis was carried out, based on the data of 36 patients who underwent transcatheter arterial embolization for acute nonvariceal upper gastrointestinal bleeding in 2013 to 2015 in our center. An analysis was performed between early rebleeding rates, mortality and the following factors: patient sex, age, number of units of packed red blood cells and packed plasma administered to the patients, length of hospital stay, therapeutic or prophylactic embolization.

Results

The technical success rate of the embolization procedure was 100%. There were 15 (41.70%) therapeutic embolizations and 21 (58.3%) prophylactic embolizations. There was a 77.8% clinical success rate. Following embolization, 10 (27.80%) patients had repeated bleeding and 9 (25.0%) patients died. Significant associations were found between rebleeding and prophylactic embolization (OR = 10.53; p = 0.04) and between mortality and prophylactic embolization (OR = 10.53; p = 0.04) and units of packed red blood cells (OR = 1.25; p < 0.01).

Conclusions

In our experience, transcatheter arterial embolization is a safe treatment method for acute nonvariceal upper gastrointestinal bleeding and a possible alternative to surgery for high-risk patients.

Onyx extravasation during embolization of a brain arteriovenous malformation

During Onyx embolization to treat brain arteriovenous malformation (AVM), carefully observing the penetration of Onyx to the nidus is important in order to avoid complications such as hemorrhage, ischemia, and difficulty with microcatheter removal. We encountered a case of Onyx extravasation during embolization of a cerebellar AVM confirmed by surgical resection and pathological analysis. The patient was a 44-year-old man with Spetzler-Martin grade I cerebellar AVM who underwent Onyx embolization prior to resection of the brain AVM. While injecting Onyx into the nidus using the "plug-and-push" technique, Onyx extravasation was observed. Onyx injection was paused and subsequently restarted, thereby allowing continuation of embolization. An oblate Onyx cast that was entirely covered in cerebellar tissue was removed during total resection of the AVM, performed the same day. The surgically removed oblate Onyx cast did not contain brain tissue or vessel wall, and immunohistochemical staining against glial fibrillary acidic protein (GFAP) showed Onyx penetration into GFAP-positive cerebellar tissue. Onyx extravasation was confirmed based on intraoperative findings during resection as well as pathological findings. The patient has been followed for four years postoperatively, and adverse events caused by Onyx extravasation have not been observed. Unexpected cast of Onyx, remote from the vascular architecture of the AVM, may represent an intra-parenchymal extravasation.

New advances in lower gastrointestinal bleeding management with embolotherapy

Lower gastrointestinal bleeding (LGIB) is associated with high morbidity and mortality. Embolization is currently proposed as the first step in the treatment of acute, life-threatening LGIB, when endoscopic approach is not possible or is unsuccessful. Like most procedures performed in emergency setting, time represents a significant factor influencing outcome. Modern tools permit identifying and reaching the bleeding site faster than two-dimensional angiography. Non-selective cone-beam CT arteriography can identify a damaged vessel. Moreover, sophisticated software able to detect the vessel may facilitate direct placement of a microcatheter into the culprit vessel without the need for sequential angiography. A further important aspect is the use of an appropriate technique of embolization and a safe and effective embolic agent. Current evidence shows the use of detachable coils (with or without a triaxial system) and liquid embolics has proven advantages compared with other embolic agents. The present article analyses these modern tools, making embolization of acute LGIB safer and more effective.

Endovascular treatment of a pulmonary artery pseudoaneurysm caused by Swan-Ganz catheter deployment in an anticoagulated patient

We present a case report of an anticoagulated 78-year old man presenting a pulmonary artery pseudoaneurysm following Swan-Ganz catheter deployment after an aortic valve and aortic root replacement. Diagnosis was established by cone beam CT angiography and catheter angiographyand embolisation was achieved via a combination of plug and glue. This case emphasises the importance of endovascular techniques in the management of iatrogenic pulmonary pseudoaneurysms and shows the benefit of using highly hemostatic polymeric agent in anticoagulated patients to obtain a rapid and effective occlusion.

Ethylene vinyl alcohol copolymer (Onyx®) in peripheral interventional radiology: indications, advantages and limitations

Onyx(®) is a remarkable liquid embolizing agent that may allow a well-trained operator to undertake challenging embolization procedures. In multiple interventional radiology indications, the physico-chemical properties of Onyx(®) allow safe embolization. The purpose of this article is to review the advantages and disadvantages of Onyx(®) and identify its main indications.

What if endoscopic hemostasis fails? Alternative treatment strategies: interventional radiology

Since the 1960s, interventional radiology has played a role in the management of gastrointestinal bleeding. What began primarily as a diagnostic modality has evolved into much more of a therapeutic tool. And although the frequency of gastrointestinal bleeding has diminished thanks to management by pharmacologic and endoscopic methods, the need for additional invasive interventions still exists. Transcatheter angiography and intervention is a fundamental step in the algorithm for the treatment of gastrointestinal bleeding.

Superselective arterial embolization of the superior mesenteric artery for the treatment of gastrointestinal hemorrhage following allogeneic hematopoietic stem cell transplantation

Superselective arterial embolization is a common therapeutic procedure for cases of visceral hemorrhage. However, until now, it has not been applied in the treatment of gastrointestinal (GI) hemorrhage caused by acute graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation. We describe a case presenting with persistent GI bleeding associated with acute GVHD successfully treated by superselective arterial embolization of the superior mesenteric artery with gelatin sponge after noneffective conventional management. This case will help guide hematologists to deal with a similar situation in the future.