The use of cyanoacrylate adhesives in the management of congenital vascular malformations

Acinetobacter pittii thrombophlebitis complicating cyanoacrylate closure procedure

Chronic venous disease is a common condition causing pain, discomfort, and skin changes that effect quality of life and productivity. Various treatment modalities have been developed to manage retrograde venous blood flow and its associated complications, ranging from conservative therapy to more invasive techniques such as endothermal ablation and cyanoacrylate closure (CAC). Recently, CAC has gained popularity due to its faster recovery time and lower incidence of postprocedure discomfort and complications. The most commonly reported side effects include phlebitis, access site bruising or pain, and dermatitis. We present a case of phlebitis caused by Acinetobacter pittii following a CAC procedure using the VenaSeal device (Medtronic) in a patient with diabetes. The patient required surgical resection of the affected vein and prolonged antibiotic therapy. Bacterial contamination of the cyanoacrylate adhesive within a vein poses a significant treatment challenge with antibiotics alone due to biofilm production. Aggressive source control with removal of the adhesive-treated vein could be required for treatment of endovascular infections resulting from these common procedures.

Novel temperature responsive polymer based sealant for embolization

A sealant has been developed that improves upon current catheter-based treatments in the following ways: 1) Efficient delivery system, 2) No in situ polymerization, 3) No harmful byproducts, and 4) Cost-effective formulation. During the development process, particular attention was given to materials that were tunable, safe, and effective sealant agents. The thermo-responsive properties of poly(N-isopropylacrylamide) (PNIPAM) provides an ideal foundation to develop an optimized solution. Through a combination of model-based and material testing, a hydrogel was developed that balances conformational factors to achieve a customized transition temperature, radiopacity suitable for visualization, mechanical properties suitable for delivery via 3Fr catheter, sufficient cohesion once applied to resist migration under physiological pressures and an improved safety profile. Two applications, embolization of lymphatic leakage and exclusions of the left atrial appendage (LAA), to eliminate LAA dead space to reduce the risk of thromboembolic events, were considered. The material and benchtop results for this product demonstrate the suitability of this new material not only for these applications but also for other potential healthcare applications.

Retrieval of n-Butyl Cyanoacrylate Cast Migrated to the Dorsalis Pedis and Posterior Tibial Artery During Embolization of the Deep Circumflex Iliac Artery Using the Stent Retriever Device: A Case Report

CLINICAL IMPACT

This case highlights the innovative application of stent retriever devices for retrieving migrated NBCA casts, traditionally used for stroke management in peripheral arterial occlusions. This adaptation offers clinicians a new, effective tool for managing embolization complications, such as unintended material migration that can cause severe ischemia. Implementing this technique could change clinical practice by providing a reliable method to swiftly address and resolve potentially limb-threatening situations, thereby improving patient outcomes and procedural safety. This advancement in interventional radiology enhances clinicians' ability to handle complex embolic events with greater confidence and efficacy.

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.

Photomodulated Extrusion as a Localized Endovascular Hydrogel Deposition Method

Minimally invasive endovascular embolization is used to treat a wide range of diseases in neurology, oncology, and trauma where the vascular morphologies and corresponding hemodynamics vary greatly. Current techniques based on metallic coils, flow diverters, liquid embolics, and suspended microspheres are limited in their ability to address a wide variety of vasculature and can be plagued by complications including distal migration, compaction, and inappropriate vascular remodeling. Further, these endovascular devices currently offer limited therapeutic functions beyond flow control such as drug delivery. Herein, a novel in situ microcatheter-based photomodulated extrusion approach capable of dynamically tuning the physical and morphological properties of injectable hydrogels, optimizing for local hemodynamic environment and vascular morphology, is proposed and demonstrated. A shear thinning and photoactivated poly(ethylene glycol diacrylate)-nanosilicate (PEGDA-nSi) hydrogel is used to demonstrate multiple extrusion modes which are controlled by photokinetics and device configurations. Real-time photomodulation of injected hydrogel viscosity and modulus is successfully used for embolization in various vasculatures, including high-flow large vessels and arterial-to-arterial capillary shunts. Furthermore, a generalizable therapeutic delivery platform is proposed by demonstrating a core-shell structured extrusion encapsulating doxorubicin to achieve a more sustained release compared to unencapsulated payload.

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

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

Ophthalmic artery occlusion following n-butyl cyanoacrylate embolization of an orbital arteriovenous malformation

A 33-year-old pregnant woman presented with six months of right-sided proptosis. Neuroimaging revealed a right orbital arteriovenous malformation arising from the second segment of the ophthalmic artery. As she was 9 weeks pregnant, the decision was made to monitor her closely. Over the following six months, her proptosis progressed, accompanied by decreased visual acuity, afferent pupillary defect, and red desaturation concerning for compressive optic neuropathy. After planned c-section, she underwent embolization with n-butyl cyanoacrylate. Upon awakening after embolization, she had no light perception vision from her right eye and was found to have ophthalmic artery obstruction. She ultimately developed a blind painful right eye and underwent enucleation with histopathology demonstrating glue in the central retinal artery, posterior ciliary arteries, and choroid. This case highlights ophthalmic artery occlusion as a rare complication of orbital arteriovenous malformation embolization and demonstrates correlating histopathological findings, which have not previously been reported.

Silk-elastinlike protein-based hydrogels for drug delivery and embolization

Silk-Elastinlike Protein-Based Polymers (SELPs) can form thermoresponsive hydrogels that allow for the generation of in-situ drug delivery matrices. They are produced by recombinant techniques, enabling exact control of monomer sequence and polymer length. In aqueous solutions SELP strands form physical crosslinks as a function of temperature increase without the addition of crosslinking agents. Gelation kinetics, modulus of elasticity, pore size, drug release, biorecognition, and biodegradation of SELP hydrogels can be controlled by placement of amino acid residues at strategic locations in the polymer backbone. SELP hydrogels have been investigated for delivery of a variety of bioactive agents including small molecular weight drugs and fluorescent probes, oligomers of glycosaminoglycans, polymeric macromolecules, proteins, plasmid DNA, and viral gene delivery systems. In this review we provide a background for use of SELPs in matrix-mediated delivery and summarize recent investigations of SELP hydrogels for controlled delivery of bioactive agents as well as their use as liquid embolics.

Endovascular embolisation of external carotid artery system haemorrhage in radiated nasopharyngeal carcinoma

PURPOSE

To review the effectiveness and safety of embolisation in managing haemorrhage from the external carotid artery (ECA) system in radiated nasopharyngeal carcinoma (NPC) patients.

METHODS

Radiated NPC patients who presented with severe oronasal bleeding and underwent digital subtraction angiography that excluded blowouts from the internal carotid artery from 2011 to 2021 were reviewed. Those who subsequently underwent embolisation of the ECA system were analysed for technical success rate, post-embolisation re-bleeding rate and complications.

RESULTS

Seventeen embolisations were performed in fifteen patients during the 10-year period. The technical success rate was 100%, however the early haemostatic rate (no re-bleed within 7 days of embolisation) was 70.6% (12/17) and the overall long-term haemostatic rate was 58.8% (10/17). The re-bleed rates of targeted and empiric embolisations were 33.3% (3/9) and 50.0% (4/8), respectively. The re-bleed rates with liquid agents, coils and particles were 0% (0/7), 33.3% (1/3) and 85.7% (6/7), respectively. Amongst the embolisations utilising liquid agents, 71.4% (5/7) were targeted, distal embolisations. All re-bleeds underwent surgical ligation or repeat embolisation; half of them further experienced recurrent bleeding. There were no significant complications with embolisation.

CONCLUSION

Although embolisation of the ECA system in NPC has a high technical success rate and is safe, re-bleeding appears to be common. Targeted, distal embolisation with liquid embolics appear to have good haemostatic effect. Clinicians should be aware that patients may need repeated procedures to secure haemostasis.

Emerging Polymer Materials in Trackable Endovascular Embolization and Cell Delivery: From Hype to Hope

Minimally invasive endovascular embolization is a widely used clinical technique used for the occlusion of blood vessels to treat various diseases. Different occlusive agents ranging from gelatin foam to synthetic polymers such as poly(vinyl alcohol) (PVA) have been commercially used for embolization. However, these agents have some drawbacks, such as undesired toxicity and unintended and uncontrolled occlusion. To overcome these issues, several polymer-based embolic systems are under investigation including biocompatible and biodegradable microspheres, gelling liquid embolic with controlled occlusive features, and trackable microspheres with enhanced safety profiles. This review aims to summarize recent advances in current and emerging polymeric materials as embolization agents with varying material architectures. Furthermore, this review also explores the potential of combining injectable embolic agents and cell therapy to achieve more effective embolization with the promise of outstanding results in treating various devastating diseases. Finally, limitations and challenges in developing next-generation multifunctional embolic agents are discussed to promote advancement in this emerging field.

Sunlight activated film forming adhesive polymers

Stimuli-sensitive biomaterials that are activated by light are in need of formulations that are stable under indoor lighting yet can be activated under direct sunlight. Carbene-based bioadhesives are a new generation of film-forming polymers that are stable under indoor lighting yet are rapidly activated with low-energy UVA light, but have never been evaluated under sunlight exposure. Previous investigations have evolved two flexible carbene-based platforms, where aryl-diazirine is grafted on to polyamidoamine dendrimers (PAMAM-NH₂; generation-5) or hydrophobic liquid polycaprolactone tetrol to yield G5-Dz_x and CaproGlu, respectively. For the first time the activation of G5-Dz_x and CaproGlu is investigated by natural sunlight with intensities up to 10 mW·cm^-2. Structure-property relationships of bioadhesion are investigated by: (1) joules dose of sunlight; (2) bioadhesive polymer structure; and (3) optical concentrators of magnifying glass and Fresnel lens. Using only natural sunlight, adhesion strength could be tuned from 20 to 150 kPa with crosslinking achieved in under 1 min. The results show that carbene-based polymers are a class of stimuli-sensitive biomaterials that are stable to indoor lighting, yet can be rapidly activated under direct sunlight, which may be useful for topical film forming polymers or as active ingredients in sunscreen formulations.

Long Vascular Sheaths for Transfemoral Neuroendovascular Procedures in Children

PURPOSE

To evaluate the safety and efficacy of long vascular sheaths for transfemoral neuroendovascular procedures in children.

MATERIALS AND METHODS

A retrospective evaluation of transfemoral neuroendovascular procedures in children <18 years, using long sheaths was undertaken analyzing procedure type, fluoroscopic times, technical success, access site and systemic complications. Twenty-seven consecutive procedures were included over a 2-year period. Mean age was 8.4 years (standard deviation [SD] 6.3) (range 17.0 months-16.3 years).

RESULTS

Patients were 44% female and mean weight was 35.0 kg (SD 22.8) (range 9.8-72.2 kg). A third of the procedures were performed in ≤15 kg children. The most common procedure was for embolization (n=13, 48.1%) and the most common indication was dual microcatheter technique (52%). The most common device used was the 5 Fr Cook Shuttle sheath. Mean fluoroscopy time was 61.9 minutes (SD 43.1). Of these procedures, 93% were technically successful. Femoral vasospasm, when present, was self-limiting. Complications (3/27, 11.1%) included groin hematoma (n=1), neck vessel spasm that resolved with verapamil (n=1), and intracranial thromboembolism (n=1), with no significant difference between the ≤15 kg and >15 kg subcohorts. There were no aorto-femoro-iliac or limb-ischemic complications.

CONCLUSION

Long vascular sheaths without short femoral sheaths can be safely used for pediatric neuroendovascular procedures as they effectively increase inner diameter access without increasing the outer sheath diameter. This property increases the range of devices used and intracranial techniques that can be safely performed without arterial compromise, thus increasing the repertoire of the neurointerventionist.

Advancements in the development on new liquid embolic agents for use in therapeutic embolisation

This review covers the current state-of-the-art in the development of liquid embolics for therapeutic embolisation.

Management of extracranial arteriovenous malformations of the head and neck

The purpose of this study was to review the outcomes of the different therapies for extracranial head and neck arteriovenous malformations (AVMs). AVMs are high-flow congenital vascular anomalies. They are composed of a complex system of vessels directly connecting feeding arteries to draining veins forming a nidus. They may be potentially life-threatening due to progressive symptoms and infiltrative disease. Extracranial AVMs most commonly affect the head and neck area (47.4%) followed by the extremities (28.5%). AVMs are best characterized as being either focal or diffuse. Focal AVMs have good outcomes following adequate treatment. Diffuse lesions have multiple feeding vessel, which results in high rates of recurrence despite treatment. The management of AVMs includes conventional surgery and endovascular techniques. A combination of embolization and surgical resection has become the treatment of choice over the last years. The main goal of both forms of treatment being the complete blockage or resection of the nidus. Transcatheter embolization of vessels has evolved over the years and new embolic agents have emerged. The types of materials available for embolization are classified into mechanical devices, liquid agents and particulates. Efficacy, rate of recurrence and most common complications were evaluated. AVMs recurrence after embolization or resection is reported in up to 80% of cases. Incomplete resection and embolization can induce aggressive growth of the remaining nidus and the risk of progression is up to 50% within the first 5 years and recurrences can occur up to 10 years later. Although ethanol seems to be associated with the highest degree of cure and permanent occlusion, the overall complication rate reported was 48%. Other materials, such as cyanoacrylate, have obtained modest rates of complete remission, while the reported rates of complete regression of AVMs with Fibrin glue and Polyvinyl alcohol are above 50%. At present, there are no unified agreement on the ideal embolic agent. Therefore, a multidisciplinary approach is recommended to support decision making about the best therapeutic approach and to achieve optimal outcome. A long-term post-treatment follow-up is recommended to recognize early recurrence.

Advances in Biomaterials and Technologies for Vascular Embolization

Minimally invasive transcatheter embolization is a common nonsurgical procedure in interventional radiology used for the deliberate occlusion of blood vessels for the treatment of diseased or injured vasculature. A wide variety of embolic agents including metallic coils, calibrated microspheres, and liquids are available for clinical practice. Additionally, advances in biomaterials, such as shape-memory foams, biodegradable polymers, and in situ gelling solutions have led to the development of novel preclinical embolic agents. The aim here is to provide a comprehensive overview of current and emerging technologies in endovascular embolization with respect to devices, materials, mechanisms, and design guidelines. Limitations and challenges in embolic materials are also discussed to promote advancement in the field.

Cyanoacrylate closure for peripheral veins: Consensus document of the Australasian College of Phlebology

Background

Cyanoacrylates are fast-acting adhesives used in procedural medicine including closure of superficial wounds, embolization of truncal vessels pre-operatively, vascular anomalies, visceral false aneurysms, endoleaks, gastrointestinal varices and gastrointestinal bleeding. More recently, catheter-directed cyanoacrylate adhesive closure was introduced as an alternative to endovenous thermal ablation (ETA) to occlude superficial veins of the lower limbs.

Objectives

To formulate policies for the safe and effective delivery of cyanoacrylate adhesive closure procedures in Australasia, based on current experience and evidence.

Methods

A panel of phlebologists including vascular surgeons, interventional radiologists, dermatologists and research scientists systematically reviewed the available data on cyanoacrylate products used in medicine and shared personal experience with the procedure. The reviewed material included bibliographic and biomedical data, material safety data sheets and data requested and received from manufacturers. Results and recommendations: Cyanoacrylate adhesive closure appears to be an effective treatment for saphenous reflux with occlusion rates at 36 months of 90–95%. We recommend a maximum dose of 10 mL of cyanoacrylate per treatment session. Serious complications are rare, but significant. Hypersensitivity to acrylates is reported in 2.4% of the population and is an important absolute contraindication to cyanoacrylate adhesive closure. 1 Post-procedural inflammatory reactions, including hypersensitivity-type phlebitis, occur in 10–20% of patients. 2 In the long term, cyanoacrylate adhesive closure results in foreign-body granuloma formation within 2–12 months of the procedure. We recommend against the use of cyanoacrylate adhesive closure in patients with uncontrolled inflammatory, autoimmune or granulomatous disorders (e.g. sarcoidosis). Caution should be exercised in patients with significant active systemic disease or infection and alternative therapies such as thermal ablation and foam sclerotherapy should be considered.

Conclusions

Cyanoacrylate adhesive closure appears to be an effective endovenous procedure, with short-term closure rates comparable to ETA and therefore greater efficacy than traditional surgery for treating superficial veins of the lower limbs. Ongoing data collection is required to establish the long-term safety.

Tissue adhesive for vascular access devices: who, what, where and when?

Despite vascular access devices (VADs) being vital for patient care, device failure rates are unacceptably high with around 25% of central venous devices, and 30-40% of peripheral venous devices, developing complications that result in VAD failure. The use of tissue adhesive is a novel method of securing VADs and is gaining popularity, however the evidence base guiding its clinical use is still emerging. This article aims to review the types and properties of tissue adhesives, provide an overview of the existing evidence base, and discuss how tissue adhesives may be used in clinical practice.

Full recovery after non-target cerebral embolization of n-butyl-cyanoacrylate occurred during emergency treatment of a facial arteriovenous malformation

Background

Non-target embolization is a well-known complication of endovascular procedures for arteriovenous malformation. However, few reports have described non target encephalic embolization, detailing its temporal evolution.

Case presentation

A 41-year-old man presented with a massive hemorrhage in the oral cavity due to an arteriovenous malformation involving the left hemiface and tongue. Under conscious sedation, selective angiography was followed by endovascular embolization with a mixture of n-butyl-cyanoacrylate-methacryloxy-sulfolane (NBCA-MS) with Lipiodol. The hemorrhage was successfully arrested, but the procedure was complicated with a reflux of embolic material from the right external carotid artery into the common carotid, caused by strong unexpected coughing. Non-target embolization was confirmed by emergency CT and subsequent MRI. After initial neurological impairment, the patient recovered fully and was discharged after one week. No sequelae were confirmed by 9-months follow-up with CT and MRI. We describe technical aspects, multimodality imaging, clinical presentation, and follow-up of this peculiar case.

Conclusion

Endovascular embolization of AVM fed by the external carotid is at risk for non-target brain embolization and general anesthesia should be considered to prevent inadvertent movements and master the delivery of the embolic agent A small amount of Lipiodol / NBCA-MS may be fully tolerated by the brain matter and partially reabsorbed without permanent deficit.

Combined glue embolization and excision for the treatment of venous malformations

Background

The purpose of this study was to evaluate safety, technical success, and clinical outcomes of treatment for venous malformations using n-BCA glue embolization immediately prior to excision. Sixty three patients (22 male, 41 female; mean age 12 years (range 1–25)) who underwent 70 procedures for extremity and trunk venous malformations were reviewed. Indications for treatment included pain (100%), swelling (22%), and diminished range of motion (16%). Thirty seven patients (59%) had undergone prior stand-alone interventional or surgical treatment but were persistently symptomatic. Safety, technical and clinical success were retrospectively assessed.

Results

Embolization was technically successful in 100% of patients. Mean lesion size was 3.0 × 2.9 × 5.7 cm. Three patients (5%) underwent planned, second stage procedures for lesions intentionally not treated at the first procedure. Four patients (6%) underwent an unplanned, second stage procedure for residual disease after the primary operation. Mean and median follow-up duration were 18 and 17 months, respectively (range 3 to 35 months). Symptomatic improvement was achieved in 58 patients (92%), of whom 41 (65%) reported complete elimination of pain. There were no recognized instances of nontarget embolization or other complications of the interventional procedure. One patient required additional surgery for wound dehiscence and one patient developed an abscess requiring incision and drainage. Minor surgical complications included surgical site skin infections (n = 5) and numbness (n = 1). Mean and median surgical blood loss volumes were 131 mL and 10 mL, respectively. One patient required perioperative blood transfusion.

Conclusions

Extremity and truncal venous malformations can be safely and effectively treated in a single-stage fashion using glue embolization immediately preceding excision.

Retrieval of a migrated N-butyl-2 cyanoacrylate cast using a snare-kit system during dural AVF embolization: A case report

N-butyl-2 cyanoacrylate (NBCA) is a liquid embolic material that is widely used in various endovascular procedures because of its permanent and rapid vascular occluding effect regardless of the coagulation profile of the patient. However, NBCA migration to unintended vessels may result in serious complications. This report describes the retrieval of a migrated NBCA cast from the transverse-sigmoid sinus during dural arteriovenous fistula embolization using a transvenous snaring technique.

Initial experience with precipitating hydrophobic injectable liquid in cerebral arteriovenous malformations

BACKGROUND

Precipitating hydrophobic injectable liquid is a newly introduced liquid embolic agent for endovascular embolization with some technical advantages over other liquid embolic agents. We present our initial experience with precipitating hydrophobic injectable liquid in the endovascular treatment of cerebral arteriovenous malformations.

METHODS

From October 2015 to January 2018, 27 patients harboring cerebral arteriovenous malformations underwent endovascular embolization with precipitating hydrophobic injectable liquid 25. Clinical features, angiographic results, procedural details, complications, and follow-up details were retrospectively analyzed.

RESULTS

Twenty-seven patients with cerebral arteriovenous malformations were included. Total obliteration in one endovascular session was confirmed for 14/27 (52%) patients. Partial embolization was attained in 13 patients (48%) in whom staged treatment with following radiosurgery or surgery was planned. No mortality was recorded in this series. Complications during or after the embolization occurred in six of 27 (22.2%) patients.

CONCLUSION

In our initial experience, precipitating hydrophobic injectable liquid has acceptable clinical outcome comparable to other liquid embolic agents. Although this is the largest reported study in arteriovenous malformation treatment with precipitating hydrophobic injectable liquid, further studies are needed to validate its safety and efficacy.

Embolization as the Primary Treatment for Mandibular Arteriovenous Malformations: An Analysis of 50 Literature Reports and of an Illustrative Case

PURPOSE

The aim of the present report is to describe 50 cases in the literature of mandibular arteriovenous malformations (AVMs) in which embolization was the primary treatment and to discuss details such as age, gender, materials used, outcome of embolization, time of follow-up, and intra- or postprocedure complications. An illustrative case in which reossification was noticed after embolization also is presented.

PATIENTS AND METHODS

The study was carried out in 2 steps. In the first, an electronic search without time restriction for embolization as the primary treatment for mandibular AVMs was performed on Medline through PubMed. In the second, the case of a patient with mandibular AVM and massive oral bleeding episodes is described after a long-term follow-up.

RESULTS

Clinical stability with the cessation of oral bleeding episodes was detected in 25 cases and 2 cases were planned for another embolization session. Clinical stability and reossification were detected in 23 of the 50 cases included. Complications were reported in 50% of cases, but most were minor and transient.

CONCLUSION

Currently, owing to more sophisticated imaging techniques, the diagnosis of mandibular AVMs is quicker and new, less invasive techniques that avoid surgical resection have proved effective. It should be emphasized that these techniques are not without complications and that long-term monitoring is extremely important.

Assessment of periprocedural hemodynamic changes in arteriovenous malformation vessels by endovascular dual-sensor guidewire

Endovascular embolization is an important modality in the treatment of brain AVMs. Nowadays staged embolization is the method of choice for the prevention of perioperative hemorrhagic complications. Current theory suggests that simultaneous occlusion of more than 60% of AVM volume induces significant redistribution local blood flow. That, in turn, may lead to hemorrhage due to AVM rupture. Aside from angiographic findings, there is still no method that predicts the degree of safe partial embolization. Intraluminal measurement of flow velocity and pressure in the vicinity of the AVM nidus might allow detecting the changes in local hemodynamics. That can provide a valuable data and shed the light on the origin of vascular catastrophes. Ten patients underwent 12 embolization sessions with intraluminal flow velocity and pressure monitoring. The measurements were performed by dual-sensor guidewire. The "Combomap" (Volcano) system with Combowire microguidewires was chosen for measurements, as there is a documented experience of safe use of said guidewires in the cerebral vasculature. The findings observed during the study matched empirical data as well as the current physiological hypothesis of AVM hemorrhage. In conjunction with DSA runs, intraluminal flow velocity and pressure monitoring has the potential to become a valuable tool in AVM treatment.

Expert review on the VenaSeal® system for endovenous cyano-acrylate adhesive ablation of incompetent saphenous trunks in patients with varicose veins

INTRODUCTION

The treatment of incompetent truncal veins has been innovated by the introduction of minimally invasive non-thermal non-tumescent (NTNT) techniques. One of these consists of the use of cyanoacrylate glue to occlude the vein lumen by means of the VenaSeal device. Areas covered: This expert-review aims to evaluate NTNT ablation of incompetent saphenous trunks using the VenaSeal device. Expert commentary: Cyanoacrylate adhesive embolization of incompetent truncal veins using the VenaSeal device is a safe and efficacious innovative technique. Further studies are needed to evaluate anatomical and clinical outcomes at long term.

Urticarial reaction following endovascular embolization of an orbital arteriovenous malformation (AVM) with n-butyl cyanoacrylate (nBCA) glue

Orbital arteriovenous malformations (AVMs) are rare vascular lesions that may be managed with endovascular embolization followed by surgical resection. Embolization is often accomplished with n-butyl-2-cyanoacrylate (nBCA), which is considered to be a safe and effective liquid occlusive agent. Localized vascular inflammation has been associated with endovascular nBCA use in histopathologic studies, but reports of systemic hypersensitivity reactions following endovascular embolization with nBCA are rare. We present a case of a 26-year-old male who developed an intermittent systemic urticarial reaction without cardiopulmonary compromise beginning four weeks after nBCA embolization of an orbital AVM. Subsequent skin allergy testing performed by an allergist confirmed hypersensitivity to nBCA glue and the patient has since been successfully managed with daily oral antihistamines. Awareness of this rare potential complication of endovascular embolization with nBCA will aid in the counseling and management of patients with AVMs.

Polymerization kinetics of a mixture of Lipiodol and Glubran 2 cyanoacrylate glue upon contact with a proteinaceous solution

The Glubran 2 cyanoacrylate glue is a liquid embolic agent used to block blood vessels endovascularly. Typically mixed with an iodized oil (Lipiodol) for visualization under X-ray, it polymerizes when in contact with blood and tissues owing to the presence of ions and proteins. The objective of the study is to determine the influence of plasma proteins in the polymerization reaction. A triggering solution containing bovine serum albumin (BSA) and the main blood ions is used as a model of plasma. The polymerization kinetics of Glubran 2-Lipiodol mixtures is measured upon aspiration in a capillary tube and contact with the proteinaceous solution. Having varied the glue and protein concentrations, we show that glue-Lipiodol mixtures with concentrations larger or equal to 25% polymerize when put in contact with an ionic solution containing at least 4% of BSA. The reaction is decomposed into two phases: a fast zwitterionic polymerization induced by the BSA molecules followed by a slower polymerization phase. The reaction speed and extent of the solidification region mostly depend on the glue concentration. The time for the glue solution to polymerize over a 1mm thickness varies from 5s for pure glue to about 1min for a 50% glue concentration, and 10min for a 25% glue mixture. It is the first time that the kinetics of the two polymerization reactions is quantified for Glubran 2, which will provide the information needed by interventional radiologists to optimize the planning of endovascular glue injection.

Endovascular Embolization of Intracranial Infectious Aneurysms in Patients Undergoing Open Heart Surgery Using n-Butyl Cyanoacrylate

INTRODUCTION

Mycotic aneurysms are a serious complication of infective endocarditis with increased risk of intracranial hemorrhage. Patients undergoing open heart surgery for valve repair or replacement are exposed to anticoagulants, increasing the risk of aneurysm bleeding. These patients may require endovascular or surgical aneurysm treatment prior to heart surgery, but data on this approach are scarce.

METHODS

Retrospective review of consecutive patients with infectious endocarditis and mycotic aneurysms treated endovascularly with Trufill n-butyl cyanoacrylate (n-BCA) at the Cleveland Clinic between January 2013 and December 2015.

RESULTS

Nine patients underwent endovascular treatment of mycotic aneurysms with n-BCA (mean age of 39 years). On imaging, 4 patients had intracerebral hemorrhage, 2 had multiple embolic infarcts, and the rest had no imaging findings. Twelve mycotic aneurysms were detected (3 patients with 2 aneurysms). Seven aneurysms were in the M4 middle cerebral artery segment, 4 in the posterior cerebral artery distribution, and 1 in the callosomarginal branch. n-BCA was diluted in ethiodized oil (1:1 to 1:2). Embolization was achieved in a single rapid injection with immediate microcatheter removal. Complete aneurysm exclusion was achieved in all cases without complications. All patients underwent open heart surgery and endovascular embolization within a short interval, 2 with both procedures on the same day. There were no new hemorrhages after aneurysm embolization.

CONCLUSIONS

Endovascular embolization of infectious intracranial aneurysms with liquid embolics can be performed successfully in critically ill patients requiring immediate open heart surgery and anticoagulation. Early embolization prior to and within a short interval from open heart surgery is feasible.

Polymerization kinetics of n-butyl cyanoacrylate glues used for vascular embolization

Vascular embolization is a minimally invasive treatment used for the management of vascular malformations and tumors. It is carried out under X-ray by navigating a microcatheter into the targeted blood vessel, through which embolic agents are delivered to occlude the vessels. Cyanoacrylate liquid glues have been widely used for vascular embolization owing to their low viscosity, rapid polymerization/solidification rate, good penetration ability and low tissue toxicity. The objective of this study is to quantitatively investigate the physical properties of two n-butyl cyanoacrylate (nBCA) glues (Glubran 2 and Histoacryl) mixed with an iodized oil (Lipiodol) at various concentrations. We show that an homogeneous solution results from the mixing of the glue and Lipiodol, and that the viscosity, density and interfacial tension of the mixture increase with the proportion in Lipiodol. We have designed a new experimental setup to systemically characterize the polymerization kinetics of a glue mixture upon contact with an ionic solution. We observe that the whole polymerization process includes two phases: an interfacial polymerization that takes place at the interface as soon as the two liquids are in contact with a characteristic time scale of the order of the minute; a volumetric polymerization during which a reaction front propagates within the mixture bulk with a characteristic time scale of the order of tens of minutes. The polymerization rate, front propagation speed and volume reduction increase with the glue concentrations. It is the first time that such comprehensive results are obtained on liquid embolic agents.

Polymeric materials for embolic and chemoembolic applications

Percutaneous transcatheter embolization procedures involve the selective occlusion of blood vessels. Occlusive agents, referred to as embolics, vary in material characteristics including chemical composition, mechanical properties, and the ability to concurrently deliver drugs. Commercially available polymeric embolics range from gelatin foam to synthetic polymers such as poly(vinyl alcohol). Current systems under investigation include tunable, bioresorbable microspheres composed of chitosan or poly(ethylene glycol) derivatives, in situ gelling liquid embolics with improved safety profiles, and radiopaque embolics that are trackable in vivo. This article reviews commercially available materials used for embolization as well as polymeric materials that are under investigation.

Leaking pseudoaneurysm of lower limb saphenous vein graft: a rare complication and its successful treatment by endovascular embolization

A rare complication after lower limb revascularization using a saphenous vein bypass graft in a crush injury patient where the saphenous vein graft was the sole supplying vessel to the leg is described; a pseudoaneurysm developed in the saphenous vein graft and caused active profuse bleeding through the surgical wound. The aetiology of this condition is uncertain but it could occur owing to slippage of ligature from one of the tributaries of the saphenous vein. The diagnosis was made by digital subtraction angiography. The pseudoaneurysm was successfully obliterated by glue embolization, which stopped the bleeding immediately, with preservation of distal flow, thereby salvaging the limb.

Comparison of Clinical Outcomes following Glue versus Polyvinyl Alcohol Portal Vein Embolization for Hypertrophy of the Future Liver Remnant prior to Right Hepatectomy

PURPOSE

To report outcomes after portal vein embolization (PVE) and right hepatectomy in patients receiving embolization with N-butyl cyanoacrylate (NBCA) glue + central AMPLATZER Vascular Plug (AVP; glue group) or polyvinyl alcohol (PVA) particles ± coils (PVA group).

MATERIALS AND METHODS

Between March 2008 and August 2013, all patients having PVE with NBCA + AVP or PVA ± coils before right hepatectomy were retrospectively reviewed; 85 patients underwent PVE with NBCA + AVP (n = 45) or PVA ± coils (n = 40). The groups were compared using Mann-Whitney U and χ² tests.

RESULTS

Technical success of embolization was 100%. Degree of hypertrophy (16.2% ± 7.8 vs 12.3% ± 7.62, P = .009) and kinetic growth rate (3.5%/wk ± 2.0 vs 2.6%/wk ± 1.9, P = .016) were greater in the glue group versus the PVA group. Contrast volume (66.1 mL ± 44.8 vs 189.87 mL ± 62.6, P < .001) and fluoroscopy time (11.2 min ± 7.8 vs 23.49 min ± 11.7, P < .001) were significantly less during the PVE procedure in the glue group. Surgical outcomes were comparable between groups, including the number of patients unable to go onto surgery (P = 1.0), surgical complications (P = .30), length of hospital stay (P = .68), and intensive care unit admissions (P = .71). There was 1 major complication (hepatic abscess) in each group after PVE.

CONCLUSIONS

PVE performed with NBCA + AVP compared with PVA ± coils resulted in greater degree of hypertrophy of the future liver remnant, less fluoroscopic time and contrast volume, and similar complication rates.

Prioritized Venous Coiling Facilitating Endovascular Treatment of Brain Arteriovenous Malformations with a Fistulous Component

BACKGROUND

Brain arteriovenous malformation (AVM) with a fistulous component presents a treatment challenge. The presence of the fistulous component may be related to either a complication from endovascular treatment, perioperative hemorrhagic events during surgical resection, or incomplete obliteration after radiosurgery.

CASE DESCRIPTION

From December 2010 to May 2014, 7 consecutive patients (3 men, 4 women, average age, 28.7 years; age range, 11 months to 67 years) with AVMs with a high-flow fistulous component were treated at our institute with venous coiling before transarterial liquid embolization. One AVM was grade I based on the Spetzler-Martin grading system, 1 was grade II, 3 were grade III, and 2 were grade IV. The nidus size ranged from 1.7 to 6.0 cm. Four patients had pure fistulous-type lesions, and 3 had lesions of the mixed fistulous-plexiform type. All AVMs shared a common feature of a high-flow fistulous component with a large venous pouch emerging from the nidus. After endovascular embolization of the AVMs, 3 patients had complete occlusion, 3 patients had near-complete occlusion, and 1 patient had significant reduction in volume. There was no immediate complication after embolization, but 1 patient experienced delayed hemorrhage 3 days after the procedure.

CONCLUSIONS

Prioritized transarterial venous coiling is feasible for the embolization of AVMs with a high-flow fistulous component and the procedure had an acceptable complication rate.

Endoscopic management of refractory gastrointestinal non-variceal bleeding using Histoacryl (N-butyl-2-cyanoacrylate) glue

Background: Histoacryl glue (N-butyl-2-cyanoacrylate) has well-established utility in the endoscopic management of gastrointestinal variceal bleeding. The role of Histoacryl glue in non-variceal bleeding is less clear, and there are few articles describing its use in this setting.

Methods: Six patients with intractable non-variceal gastrointestinal bleeding were managed using injection of Histoacryl glue. All patients had previously failed conventional endostasis and/or interventional angioembolization and were not suitable for emergency salvage surgery due to serious comorbidities or unacceptable anaesthetic risk. An endoscopic Lipiodol-Histoacryl-Lipiodol sandwich injection technique was used in these patients. The clinical outcomes and complications were evaluated.

Results: There were four females and two males with a mean age of 55 years. Bleeding lesions included gastric ulcers (n = 2), duodenal ulcers (n = 2), duodenal gastrointestinal stromal tumor (GIST) (n = 1) and rectal ulcers (n = 1). All patients had successful Histoacryl endostasis without the requirement for salvage surgery. There was no treatment-related morbidity and no mortality. Two patients had further bleeding after initial Histoacryl endostasis, which was successfully controlled with further endoscopic Histoacryl injection.

Conclusion: Histoacryl endostasis should be included in the treatment algorithm for refractory non-variceal gastrointestinal bleeding.

A case-based approach to common embolization agents used in vascular interventional radiology

OBJECTIVE

The objective of this article is to familiarize the reader with the most commonly used embolic agents in interventional radiology and discuss an approach for selecting among the different embolic agents. This article reviews their properties and uses a case-based approach to explain how to select one.

CONCLUSION

A wide variety of embolic agents are available. Familiarity with the available embolic agents and selection of the most appropriate embolic agent is critical in interventional radiology to achieve optimum therapeutic response and avoid undesired, potentially disastrous complications such as nontarget embolization.

Imaging and interventional therapy for varicoceles

Varicocele is a common treatable cause of testicular pain, male infertility, and Leydig cell dysfunction. Scrotal ultrasonography has become the modality of choice in the diagnosis and post-treatment follow-up of varicocele. Visualization of dilated veins and reflux into the pampiniform plexus enables accurate diagnosis. Although the pathophysiology of varicocele in testicular dysfunction remains unclear, numerous studies have established significant improvement in the seminal parameters and pregnancy rates after varicocele repair. Interventional therapy is a minimally invasive effective treatment option for primary and salvage varicocele repair. This review discusses sonographic criteria used in the pre- and post-procedural evaluation of varicocele and various interventional techniques for varicocele treatment.

Sapheon: the solution?

Less invasive endovenous techniques have been shown to be as effective as open surgery in the treatment of varicose veins. Furthermore, they cause less postoperative bruising and pain and enable early return to normal activities and work. Tumescent anaesthesia is safe and obviates complications of general or spinal anaesthesia. Drawbacks are a steep learning curve and painful administration during treatment. Tumescentless techniques like Clarivein™ or VenaSeal™ Sapheon Closure System are recently under investigation. Short-term results of VenaSeal™ are comparable with thermal ablation. The procedure is safe without serious adverse events. Perioperative pain and patient discomfort with this tumescentless approach is minimal but postoperative recovery is temporarily hindered by thrombophlebitis in 14–15 % of patients. One-year results in a small feasibility study has demonstrated durable closure at this endpoint. No longer-term results are available. A randomized control trial between VenaSeal™ and Covidien ClosureFast™ is in a preparatory phase.