Transcatheter embolization with Squid, combined with other embolic agents or alone, in different abdominal diseases: a single-center experience in 30 patients

The Advantages of Non-Adhesive Gel-like Embolic Materials in the Endovascular Treatment of Benign Hypervascularized Lesions of the Head and Neck

OBJECTIVES

The use of non-adhesive gel-like embolic materials (NAGLEMs) in the endovascular treatment of hypervascularized formations in the head and neck is gaining in popularity because of a number of important characteristics involved. Their primary benefits are their capacity to penetrate diseased vasculature, effectively distribute, and, most importantly, remain controllable during the process. We reviewed the literature and evaluated the results of using NAGLEMs in comparison to other embolizing substances (namely, coils, glue, and particles) as alternative embolizing agents for patients receiving care at our clinic. The process comprised evaluating the safety, effectiveness, and technological elements of endovascular therapy used to treat two categories of hypervascular pathological abnormalities that were surgically corrected between 2015 and 2023. Arteriovenous malformations (AVMs) located in the head, neck, and paragangliomas with jugular/carotid body localization are combined by intense shunting blood flow and shared requirements for the embolic agent used in endovascular treatment (such as penetration, distribution, delayed polymerization, and controllability). An analysis of the literature was also conducted. Results showed 18 patients diagnosed with neck paragangliomas of the carotid body and jugular type. Five patients with arteriovenous malformation (AVM) of the face and neck were included, consisting of sixteen females and seven males with an average age of 55 ± 13 years. Endovascular procedures were performed using NAGLEMs (ONYX (Medtronic, Irvine, CA, USA), SQUID (Balt, Montmorency, France), and PHIL (Microvention, Tustin, CA, USA)) and dimethyl sulfoxide (DMSO)-compatible balloon catheters. All patients achieved complete or partial embolization of hypervascularized formations using one or more stages of endovascular treatment. Additionally, three AVMs of the face and two paragangliomas of the neck were surgically excised following embolization. In other instances, formations were not deemed necessary to be removed. The patients' condition upon discharge was assessed by the modified Rankin Scale (mRs) and rated between 0 and 2.

CONCLUSION

Currently, NAGLEMs are predominantly used to treat hypervascularized formations in the neck and head due to their fundamental properties. These properties include a lack of adhesion and a delay in predictable polymerization (after 30-40 min). NAGLEMs also exhibit excellent distribution and penetration throughout the vascular bed of the formation. Adequate controllability of the process is largely achieved through the presence of embolism forms of different viscosity, as well as excellent X-ray visualization.

Endovascular and surgical obliteration rates of spinal dural arteriovenous fistulae: a single UK Centre experience

OBJECTIVE

Endovascular treatment (EVT) of spinal dural arteriovenous fistulae (SDAVF) has become increasingly popular given its less invasive nature. This study aims to assess radiological obliteration rates after surgery and EVT for SDAVF in a major tertiary referral centre serving a population of 2.2 million.

METHOD

A retrospective review of all patients diagnosed with SDAVF between February 2010 and February 2018 was undertaken, identifying baseline demographics, treatment modality and the final radiological outcome (i.e., persistence of the SDAVF). Patients were identified from the departmental neurovascular database, clinical notes and imaging reports.

RESULTS

Twenty patients were identified with an angiographically confirmed SDAVF. Two (10%) were managed conservatively. Nine patients (45%) underwent EVT. Obliteration was achieved in one patient (11%) after a single procedure, while one patient required two sessions. Further surgery was required in five patients (56%) to achieve complete obliteration. Nine patients (45%) underwent surgical disconnection as first treatment. Obliteration was radiologically confirmed in eight patients (89%). No radiological (MRI or angiographic) follow-up data was available for two patients (one from each group) and these were excluded from analysis. In this study, the obliteration rate of SDAVF after surgery was superior compared to EVT (p <0.01).

CONCLUSION

Complete obliteration and recurrence rates after single treatment with EVT were inferior compared to surgical intervention. EVT may be better suited for specific presentations of SDAVF either in isolation or as an adjunct in multi-modality treatment. A national registry of outcomes may aid ongoing refinement of patient selection for EVT.

Peripheral Arteriovenous Malformation Embolization Using Squid

Materials and Methods

Between January 2018 and December 2020, twenty patients (7 men and 13 women) with peripheral high-flow arteriovenous malformations who were treated primarily with arterial embolization using squid were retrospectively included. Anatomical sites being treated included the head and neck (16), extremities (2), uterus (1), and pelvis (1). Squid was used as the sole embolic agent in 15 patients, and transarterial embolization was employed in all cases except one where direct puncture embolization was used. Treatments were delivered over one or two sessions, with or without surgery. A total of 27 sessions were carried out with an interval time ranging from 6 to 36 months between sessions.

Results

Technical success was achieved in all cases. In those patients treated with squid alone, 13 exhibited total devascularization following embolization, and a further 4 required surgical excision to achieve complete obliteration of the arteriovenous malformation. There were no major complications, cases of microcatheter entrapment, or dimethyl sulfoxide-related pain recorded. On follow-up, one patient reported persistent pain, and another patient developed a garlicky taste. All other patients reported complete resolution of symptoms following treatment.

Conclusion

This study demonstrates the successful use of squid in managing peripheral arteriovenous malformations with low complication rates and long-term stable results, therefore validating its efficacy when used alone or in combination with other embolic agents. Squid may be the preferred embolic agent in any interventional radiologist's armamentarium as it offers formulations with varying viscosities (squid-18 and squid-12). We conclude that squid should be considered as a first-line embolic agent in the management of peripheral arteriovenous malformations.

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.

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.

Translumbar type II endoleak embolization with a new liquid iodinated polyvinyl alcohol polymer: Case series and review of current literature

Purpose

To describe our experience with the use of a novel iodized Polyvinyl Alcohol Polymer liquid agent (Easyx) in type II endoleak treatment with translumbar approach.

Methods

Our case series is a retrospective review of patients with type II endoleak (T2E) treated with Easyx from December 2017 to December 2020. Indication for treatment was a persistent T2E with an increasing aneurysm sac ≥5 mm on computed tomography angiography (CTA) over a 6-month interval. Technical success was defined as the embolization of the endoleak nidus with reduction or elimination of the T2E on sequent CTA evaluation. Clinical success was defined as an unchanged or decreased aneurysm sac on follow-up CTA. Secondary endpoints included the presence of artifacts in the postprocedural cross-sectional tomographic imaging and post and intraprocedural complications.

Results

Ten patients were included in our retrospective analysis. All T2E were successfully embolized. Clinical success was achieved in 9 out of 10 patients (90%). The mean follow-up was 14 3-20 months. No beam hardening artifact was observed in follow-up CT providing unaltered imaging.

Conclusion

Easyx is a novel liquid embolic agent with lava-like characteristics and unaltered visibility on subsequent CT examinations. In our initial experience, Easyx showed to have all the efficacy requisites to be an embolization agent for type II EL management. Its efficacy, however, should be evaluated in more extensive studies and eventually compared with other agents.

Liquid Embolic Agents for Endovascular Embolization: A Review

Endovascular embolization (EE) has been used for the treatment of blood vessel abnormalities, including aneurysms, AVMs, tumors, etc. The aim of this process is to occlude the affected vessel using biocompatible embolic agents. Two types of embolic agents, solid and liquid, are used for endovascular embolization. Liquid embolic agents are usually injectable and delivered into the vascular malformation sites using a catheter guided by X-ray imaging (i.e., angiography). After injection, the liquid embolic agent transforms into a solid implant in situ based on a variety of mechanisms, including polymerization, precipitation, and cross-linking, through ionic or thermal process. Until now, several polymers have been designed successfully for the development of liquid embolic agents. Both natural and synthetic polymers have been used for this purpose. In this review, we discuss embolization procedures with liquid embolic agents in different clinical applications, as well as in pre-clinical research studies.

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.

Rheological Properties of Non-Adhesive Embolizing Compounds-The Key to Fine-Tuning Embolization Process-Modeling in Endovascular Surgery

The study of polymers' rheological properties is of paramount importance both for the problems of their industrial production as well as for their practical application. Two polymers used for embolization of arteriovenous malformations (AVMs) are studied in this work: Onyx-18^® and Squid-12^®. Viscosity curve tests and computational fluid dynamics (CFD) were used to uncover viscosity law as a function of shear rate as well as behavior of the polymers in catheter or pathological tissue models. The property of thermal activation of viscosity was demonstrated, namely, the law of dependence of viscosity on temperature in the range from 20 °C to 37 °C was established. A zone of viscosity nonmonotonicity was identified, and a physical interpretation of the dependence of the embolic polymers' viscosity on the shear rate was given on the basis of Cisco's model. The obtained empirical constants will be useful for researchers based on the CFD of AVMs. A description of the process of temperature activation of the embolic polymers' viscosity is important for understanding the mechanics of the embolization process by practicing surgeons as well as for producing new prospective embolic agents.

Type IIIb Endoleak: The Great "Masquerader" - Risks of Liquid Agent Dislocation During Sac Embolization Techniques

The diagnosis of late type III endoleaks may be very challenging on non-invasive imaging studies, and it is not unusual for type IIIb endoleaks to be misdiagnosed as type I endoleaks. The present report illustrates a type III endoleak that was misdiagnosed and treated as Type Ia endoleak. Embolization of the endoleak using a liquid embolic agent (Squid) was complicated by intraluminal graft dislodgement of the liquid agent. This unusual complication was recognised and treated successfully. Type IIIb endoleaks should always be considered in patients with persistent aneurysm sac perfusion treated with embolization using liquid embolic agents.

Internal Iliac Artery Embolization within EVAR Procedure: Safety, Feasibility, and Outcome

BACKGROUND

This study is focused on Internal Iliac Artery (IIA) embolization in patients undergoing Endovascular Aneurysm Repair (EVAR). Our aims were: to establish the feasibility of the procedure; to assess the presence of endoleak (EL) and increase in the size of the sac at follow-up; to define the need for reintervention; and to evaluate mortality rate.

METHODS

In this retrospective single-center study, EVAR-treated patients with an embolization of IIA were chosen. Coils and vascular plug were used as embolizing agents.

RESULTS

A total of 49 participants were enrolled in the study (48 men and one woman) with a median age of 76 ± 12 years. Patients had no early EL in 87.75% of cases, 8.16% had type 1a EL, 2.04% type 1b EL, and 2.04% type 2 EL, with a comprehensive technical success of 95.91%. In the follow-up, at 1 month 72.22% remained without EL, at 6 months 70.97%, and at 1 year 81.48%. In the same period, the trend of type 1 EL was 5.56% (1 month), 3.23% (6 months), and 0% (1 year). For EL type 2: 22.22% at 1 month, 25.81% at 6 months, and 16.7% at 1 year. The overall mortality was 35.58% and the re-intervention rate was 16.33%.

CONCLUSIONS

IIA embolization is a feasible and safe procedure. The presence of EL is not superior to EVAR procedures that do not involve embolization.

Preoperative Transarterial Embolization of a Large Petrotentorial Angiomatous Meningioma Using Combination of Liquid Embolic Materials: A Case Report

Intracranial angiomatous meningiomas are a rare WHO grade I histological variant of meningioma whose vascular component exceeds 50% of the total tumor area. Preoperative embolization of angiomatous meningiomas has rarely been reported previously. A 58-year-old woman was referred to our institute for a large petrotentorial hypervascular tumor presented with progressively worsening right facial paralysis and hearing loss for 6 months. Cranial computed tomography scan and magnetic resonance imaging revealed a large homogenously enhancing multilobulated mass involving middle and posterior cranial fossae with marked brainstem compression. The tumor extended into a right internal auditory canal and labyrinthine structures with destructive changes of bony structures. Magnetic resonance angiography showed hypervascularity in the tumor. Preoperative transarterial embolization using liquid embolic materials was successfully performed with resulting in almost complete devascularization of the tumor. Adequate hemostasis was achieved following gross total resection of the tumor (Simpson grade II). A histopathological examination confirmed the diagnosis of an angiomatous meningioma. Preoperative transarterial embolization of angiomatous meningioma with liquid embolic material was safe and effective in reducing perioperative blood loss and facilitating total tumor resection.

Trancatheter embolization of pulmonary artery pseudoaneurysm with detachable coils in association with non-adhesive liquid embolizing agent (Squid)

A nodular lesion at the lower left pulmonary lobe was detected in a 46 years old male during a preoperative chest X-Ray for appendicitis. To further characterise the nodule, a contrast enhanced computed tomography (CE-CT) was performed showing a 20 mm vascular lesion, which was suspected to be a pseudoaneurysm. The diagnostic angiography detected a flattening of the vascular wall with a voluminous pseudoaneurysm (PSA) in the distal portion of the tributary branch of the inferior left lobe. To treat the lesion, a 2.9F microcatheter was advanced into the sac and 4 detachable coils were placed (16-18mm Penumbra Inc) to pack the PSA. To block vascular supply to the lesion, the feeding artery was embolized with an ethylene vinyl alcohol copolymer agent (Squid Peri 18, Emboflu). The final angiographic control showed the exclusion of the pseudoaneurysmal sac which was confirmed by SEMAR™ reconstructed CE-CT scan after 40 days. Furthermore, no signs of pulmonary infarction were reported. (www.actabiomedica.it).

Bronchial artery embolization with an ethylene vinyl alcohol copolymer agent (Squid) and polyvinyl alcohol particles for treatment of hemoptysis

Bronchial artery embolization (BAE) is considered the first choice treatment for hemoptysis. To our knowledge no cases of BAE using a recent ethylene vinyl alcohol copolymer agent (Squid) have been previously mentioned. Two cases of BAE for remitting hemoptysis using Squid and polyvinyl alcohol particles are reported in this technical note. The final angiographic control confirmed full exclusion of the target territory in both cases. Both patients felt some chest pain immediately after the embolization, not requiring any medications. No more episodes of hemoptysis occurred in the following 3 months after the procedure.

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.

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.

Safety and Effectiveness of Ethylene Vinyl Alcohol Copolymer Embolization of Peripheral High-Flow Arteriovenous Malformations: Results of a Prospective Study

PURPOSE

To prospectively evaluate the efficacy and safety of a new ethylene vinyl alcohol (EVOH) copolymer-based embolic agent in the treatment of symptomatic peripheral arteriovenous malformations (AVMs).

MATERIALS AND METHODS

This prospective single-center study evaluated EVOH embolization with 3 different formulations of EVOH (Squid Peri 12 cP, 18 cP, and 34 cP; BALT Germany GmbH, Düsseldorf, Germany) in patients with symptomatic AVMs. Between April 2018 and October 2019, 36 embolization procedures in 21 patients (3 males and 18 females; mean age, 34.7 years) were performed (inclusion criteria: symptomatic peripheral AVM, ≥14 years of age, and elective embolization). Symptoms, technical aspects (transarterial, transvenous, or percutaneous approach; plug or balloon occlusion), clinical and technical success (defined as the improvement of symptoms and complete angiographic eradication of the AVM nidus), adverse events, and short-term outcomes were assessed.

RESULTS

The mean volume of the embolic agent used per session was 3.4 mL of EVOH 34 cP (standard deviation [SD], ± 5.4), 6.2 mL ± 8.1 of EVOH 18 cP, and 4.6 mL ± 10.1 of EVOH 12 cP. Angiographic success was achieved in 18 patients (85.7%). The mean follow-up was 190 days (range, 90-538 days; median, 182 days). In the follow-up assessment, findings of magnetic resonance imaging showed that 19 patients (90.5%) had a persistent state of devascularization compared with postinterventional angiography. Amelioration or complete elimination of pain was achieved in 90.0% of the patients. One patient experienced a major adverse event; minor adverse events developed in 2 patients.

CONCLUSIONS

In this study, EVOH appeared to be a safe and effective embolic agent in peripheral AVMs and had a low rate of adverse events in a limited number of patients.

The Two-Step Treatment for Giant Hepatic Hemangiomas

The aim of the present study is to analyze the feasibility and the impact of a two-step approach in the treatment of giant hemangiomas (GH) i.e., exceeding 10 cm in maximum diameter, consisting of transarterial embolization (TAE) followed by laparoscopic liver resection (LLR). Ten patients with 11 GH were treated with TAE and subsequent LLR between 2017 and 2020 (Group A). A matched cohort of 10 patients with GH treated with upfront LLR between 2014 and 2017 was identified for comparison (Group B). Data were analyzed regarding intraoperative and postoperative outcomes, including successful completion of LLR, morbidity, and mortality. Successful microparticle embolization of the GH-feeding arteries was performed in all patients in group A. In three cases a liquid embolic agent (Squid-18) was also injected to obtain complete embolization. No complications were observed after TAE. Successful surgery was performed after a mean time interval of 2.2 days from TAE without any case of conversion to laparotomy. Statistically significant differences between group A and group B were found in intraoperative blood loss (250 ± 200 vs. 400 ± 300 mL, p = 0.039), operative time (245 ± 60 vs. 420 ± 60 min, p = 0.027), and length of stay (5 ± 1 vs. 8 ± 2 days, p = 0.046). Our data suggest that two-step TAE + LLR might be a safe and effective option for surgical treatment of GH >10 cm.

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

Visceral artery aneurysms (VAAs) are rare, usually asymptomatic and incidentally discovered during a routine radiological examination. Shared guidelines suggest their treatment in the following conditions: VAAs with diameter larger than 2 cm, or 3 times exceeding the target artery; VAAs with a progressive growth of at least 0.5 cm per year; symptomatic or ruptured VAAs. Endovascular treatment, less burdened by morbidity and mortality than surgery, is generally the preferred option. Selection of the best strategy depends on the visceral artery involved, aneurysm characteristics, the clinical scenario and the operator's experience. Tortuosity of VAAs almost always makes embolization the only technically feasible option. The present narrative review reports state of the art and new perspectives on the main endovascular and other interventional options in the treatment of VAAs. Embolization techniques and materials, use of covered and flow-diverting stents and percutaneous approaches are accurately analyzed based on the current literature. Visceral artery-related considerations and targeted approaches are also provided and discussed.

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.

Management of Renal Cell Carcinoma With Extensive Caval Thrombosis Utilizing a Temporary Atrial Caval Filter Through a Combined Endovascular and Open Surgical Technique

The most common cause of neoplastic thrombotic infiltration of the inferior vena cava is renal cell carcinoma (RCC). In the present report we described a case of a patient with massive RCC and extensive neoplastic thrombosis reaching the retrohepatic tract of the inferior vena cava. After a discussion in a multidisciplinary team meeting we decided to perform a radical nephrectomy with vena cava thrombectomy along with the support of a novel removable vena cava filter in order to avoid thromboembolism during the surgical procedure. Furthermore, a preoperative renal artery embolization with a non-adhesive liquid embolic agent was performed ahead of the surgical procedure in order to reduce the risk of intraoperative bleeding. The surgical procedure performed the day after was based on a hybrid endovascular-surgical approach consisting in nephrectomy, liver derotation, cavotomy with the additional use of a novel temporary caval filter, thus reducing the risk of intraoperative thromboembolic dissemination.

Facial palsy after embolization with Squid® 12

Endovascular procedures with liquid embolic agents such as ethylene-vinyl alcohol (EVOH) copolymers are indicated before surgical treatment of cervical paraganglioma. Consequently, these agents are now available as low viscosity formulations, one of which is Squid 12, which are demonstrating superior vascular penetration. Cases of facial paralysis secondary to embolization of cervical vascular lesions with classic embolic agents have been reported in the English literature, however, this complication has not been described with new generation options such as Squid 12.

We describe the case of a 43-year-old patient with a left neck carotid paraganglioma. Embolization was performed under general anaesthesia before surgical excision. In the immediate postoperative period, the patient developed total left facial palsy. Since the imaging tests (Computed Tomography (CT) and Magnetic Resonance Imaging (MRI)) and neurological examination showed no involvement of additional cranial nerves (CN), we hypothesise that the main cause of this complication is ischemia of the vasa nervorum of CN VII secondary to embolization. Almost six months later, the patient continues to present total facial paralysis (Grade VI House-Brackmann facial paralysis scale), and palsy of the left CN X and XII as a complication secondary to surgical resection of the paraganglioma.

This case is relevant since it is the first clinical case of permanent facial paralysis secondary to embolization with Squid 12.

Emergency tips recanalisation and gastroesophageal varices embolisation with an ethylene vinyl alcohol copolymer agent (Squid) and detachable coils

Transjugular intrahepatic portosystemic shunt (TIPS) is currently indicated as first therapeutic option in the main complications of portal hypertension, including bleeding gastroesophageal varices and refractory ascites. In case of bleeding gastroesophageal varices, an adjuvant embolisation within TIPS can be useful to prevent rebleeding. In the present technical note, the management in emergency of a patient with haemorrhagic shock due to bleeding gastroesophageal varices and occluded TIPS is reported. TIPS recanalisation with an adjunctive stent and high-pressure balloon angioplasty and gastroesophageal varices embolisation using detachable coils and a non-adhesive liquid embolic agent were performed during the same emergent procedure. After the procedure, clinical stabilisation of the patient was achieved, with blood transfusions suspension and Blakemore tube removal. At 6 months, regular TIPS patency at colour Doppler and no rebleeding episodes were recorded. To our knowledge, whilst coils are routinely used for varices embolisation, non-adhesive liquid embolic agents have been never mentioned. Liquid embolic agents seem to provide a stable plug strengthening the embolising action of the coils. Further studies involving a cohort of patients with long-term follow-up will be necessary to confirm whether this association can be more effective than coils alone in gastroesophageal varices embolisation.

Embolization of peripheral arteriovenous malformations and fistulas with precipitating hydrophobic injectable liquid (PHIL®)

PURPOSE

This paper reports on the preliminary experience of a single center in the embolization of peripheral AVMs and fistulas with precipitating hydrophobic injectable liquid (PHIL^®), focusing on technical aspects and short-term clinical outcomes.

MATERIALS AND METHODS

Seven males and five females were included in this study, mean age 42.16 years. For ten of them, it was the first embolization treatment; two had been previously treated with Onyx^® embolization. PHIL^® was injected with a transarterial approach without other embolics during the same procedure. Lesions were localized in small bowel (1), colon (1), head face (5), forefoot (1), uterus (1) and thorax (3); all were symptomatic. After 30-day clinical follow-up, a contrast-enhanced CT or MR was acquired at 3 months from intervention to detect eventual lesion residual.

RESULTS

After a single embolization procedure, complete technical success was obtained in 50%, while clinical improvement without additional therapies was appreciable in all patients. No technical failure occurred; in two cases, a small amount of PHIL^® proximally refluxed in nontarget vessels without clinical effects. No tattooing effects of superficial lesions neither artifacts at CT and cone-beam CT controls were evident.

CONCLUSIONS

PHIL^® seems to be a safe and effective liquid embolic agent for the treatment of peripheral AVMs and fistulas; although a direct comparison between PHIL and Onyx was not performed, PHIL might present the advantages of reduced artifacts at postprocedural CT scan and no need for shaking time preparation, but it is more expensive due to lower volume of product for each package and slightly less radiopaque at fluoroscopy.

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.