High-flow Arteriovenous Malformations Research Articles

High-Flow Arteriovenous Malformations: Treatment Using a Venous Approach.

High-flow arteriovenous malformations (AVMs) are among the rarest and most recalcitrant lesions in medicine. Patients with these anomalies are best managed longitudinally in tertiary referral centers by dedicated multidisciplinary teams that include surgeons, dermatologists, hematologists, geneticists, and interventional radiologists. A significant percentage of these lesions cannot be cured per se and intervention can worsen symptoms or preclude effective future embolization. Existing classification systems help guide treatment, but in nearly all cases, therapy must be individualized based on patient, symptoms, and lesion angioarchitecture. For various reasons, referral to tertiary centers may be impossible for some patients. The purpose of this article is to provide an approach to the evaluation and treatment of these abnormalities.

Facial Artery Arteriovenous Malformation: An Interdisciplinary Approach to Management

Arteriovenous malformations (AVMs) are rare vascular abnormalities that can result from defects in blood vessels. They are not often found in the facial area, and this report describes a case of a high-flow AVM in an adult patient with swelling in the left mandibular region. Since there were no complications related to swelling, a comprehensive investigation ultimately resulted in the accurate identification of the AVM. The potential risks associated with these malformations highlight the importance of accurate diagnosis and comprehensive diagnostic approaches involving detailed patient history, clinical examination, and advanced imaging techniques. Computed tomography angiography confirmed the diagnosis before undergoing angioembolization and complete excision of the AVM. This case underscores how important accurate diagnosis is for preventing serious complications associated with AVMs and emphasizes using a multidisciplinary strategy when managing these uncommon vascular anomalies.

Acquired High Flow Arteriovenous Malformation of the Lower Lip Induced by Hormonal Variation- Report of a Rare Case and Review

Arteriovenous malformations (AVMs) are uncommon vascular lesions. AVMs are the most serious type of vascular malformations, causing substantial deformity and functional disability. AVMs of the acquired type are rarely confronted in the head and neck region. They may present as a medical emergency while performing dental procedures due to their potential for uncontrollable haemorrhage. Dental professionals should be aware of their potentially fatal complications and management. Accurate diagnosis of AVMs is critical and their management remains challenging. Vascular anomalies involving the lips can negatively impact the functionality and facial appearance. In this article, we discuss a very rare case of acquired AVM of the lower lip triggered by hormonal variation occurring during menopause in a female patient, 58 years of age. There are no reported cases of acquired AVM of the lip with hormonal variation occurring during menopause as the trigger for proliferation of the lesion. An overview of the clinical, etiological, diagnostic and management aspects of head and neck region-acquired AVMs is also presented in this paper.

Shortened Cerebral Circulation Time Predicts Resistance to Obliteration in High-Flow Brain Arteriovenous Malformations After Stereotactic Radiosurgery.

Treatment selection for brain arteriovenous malformations (BAVMs) is complicated by BAVM size, location, and hemodynamics. Quantitative digital subtraction angiography is used to quantify the hemodynamic impact of BAVMs on cerebral circulation. This study investigated the association between cerebral circulation time and the complete obliteration (CO) rate of BAVMs after stereotactic radiosurgery (SRS). We analyzed the data of 143 patients who underwent SRS for BAVMs between January 2011 and December 2019 in our institute. Their pre-SRS magnetic resonance imaging and angiography images were analyzed to acquire BAVM characteristics and quantitative digital subtraction angiography parameters. Modified cerebral circulation time (mCCT) was defined as the time difference between the bolus arrival time of the ipsilateral cavernous internal carotid artery and that of the parietal vein, as determined from the lateral view of images obtained using digital subtraction angiography. Cox regression with hazard ratios and Kaplan-Meier analyses were conducted to determine the associations between the parameters and BAVM CO after SRS. Of the 143 patients, 101 (70.6%) achieved BAVM CO. According to the multivariate analyses, an increased mCCT (hazard ratio: 1.24, P = .041) was the independent factor associated with BAVM CO after adjustment for age, sex, hemorrhagic presentation, a BAVM volume of >5 cm3, and a margin dose of >18 Gy. Individuals with an mCCT of ≤2.32 s had a lower 36-month probability of BAVM CO than did those with an mCCT of >2.32 s (44.1% ± 6.8% vs 63.3% ± 5.6%, P = .034). The hemodynamic impact of high-flow BAVM demonstrated by a shortened mCCT is associated with a lower BAVM CO rate after SRS.

Magnetic resonance - guided treatment of low-flow vascular malformations and the technologies to potentiate adoption.

Vascular malformations are congenital, non-neoplastic lesions that arise secondary to defects in angiogenesis. Vascular malformations are divided into high-flow (arteriovenous malformation) and low-flow (venous malformations and lymphatic malformations). Magnetic resonance imaging (MRI) is the standard for pre-and post-intervention assessments, while ultrasound (US), X-ray fluoroscopy and computed tomography (CT) are used for intra-procedural guidance. Sclerotherapy, an image-guided therapy that involves the injection of a sclerosant directly into the malformation, is typically the first-line therapy for treating low-flow vascular malformations. Sclerotherapy induces endothelial damage and necrosis/fibrosis with eventual involution of the malformation. Image-guided thermal therapies involve freezing or heating target tissue to induce cell death and necrosis. MRI is an alternative for intra-procedural guidance and monitoring during the treatment of vascular malformations. MR can provide dynamic, multiplanar imaging that delineates surrounding critical structures such as nerves and vasculature. Multiple studies have demonstrated that MR-guided treatment of vascular malformations is safe and effective. This review will detail (1) the use of MR for the classification and diagnosis of vascular malformations, (2) the current literature surrounding MR-guided treatment of vascular malformations, (3) a series of cases of MR-guided sclerotherapy and thermal ablation for the treatment of vascular malformations, and (4) a discussion of technologies that may potentiate interventional MRI adoption including high intensity focused ultrasound and guided laser ablation.

Bleomycin electrosclerotherapy (BEST) for the treatment of vascular malformations. An International Network for Sharing Practices on Electrochemotherapy (InspECT) study group report.

Biomedical applications of electroporation are expanding out of the field of oncology into vaccination, treatment of arrhythmias and now in the treatment of vascular malformations. Bleomycin is a widely used sclerosing agent in the treatment of various vascular malformations. The application of electric pulses in addition to bleomycin enhances the effectiveness of the drug, as demonstrated by electrochemotherapy, which utilizes bleomycin in the treatment of tumors. The same principle is used in bleomycin electrosclerotherapy (BEST). The approach seems to be effective in the treatment of low-flow (venous and lymphatic) and, potentially, even high-flow (arteriovenous) malformations. Although there are only a few published reports to date, the surgical community is interested, and an increasing number of centers are applying BEST in the treatment of vascular malformations. Within the International Network for Sharing Practices on Electrochemotherapy (InspECT) consortium, a dedicated working group has been constituted to develop standard operating procedures for BEST and foster clinical trials. By treatment standardization and successful completion of clinical trials demonstrating the effectiveness and safety of the approach, higher quality data and better clinical outcomes may be achieved.

Prevalence and clinical features of orbital vascular anomalies in children

ABSTRACT Purpose To report the prevalence, clinical characteristics, and natural history of orbital vascular anomalies diagnosed among children over a 50-year period. Methods The medical records of all patients <19 years diagnosed with any form of an orbital vascular anomaly (OVA) at Mayo Clinic, Rochester, Minnesota from January 1 1966, through December 31 2015, were retrospectively reviewed. Results A total of 109 children were diagnosed with OVA during the 50-year period, of which 24 were from Olmsted County, MN, yielding a birth prevalence of 1 in 4,305 live births. The median age at diagnosis for the 109 patients was 1.2 years (range, 0–17.9 years) and 67 (61.5%) were female. Common presenting symptoms included proptosis in 80 (73.4%) patients, abnormalities in skin color in 45 (41.3%) patients, and pain in 18 (16.5%) patients. There were 55 (50.5%) vascular malformations [50 (91%) low-flow lymphatic malformations, 3 (5.5%) high-flow arteriovenous malformations, and 2 (3.5%) low-flow venous malformations] and 54 (49.5%) vascular tumors [53 (98%) capillary hemangiomas and 1 (2%) kaposiform hemangioendothelioma]. During a mean follow-up of 5.95 years (range 0–27.7 years), amblyopia and/or strabismus were diagnosed in 46 (43.4%) patients. Conclusions Capillary hemangiomas and low-flow lymphatic malformations comprise most of the orbital vascular anomalies in this cohort of children. Amblyopia and strabismus are common sequelae, highlighting the importance of early diagnosis and appropriate management.

Combining superselective catheterization and electrochemotherapy: A new technological approach to the treatment of high-flow head and neck vascular malformations.

The study aims to demonstrate a combination of superselective catheterization and electrochemotherapy as a feasible and effective new technological approach in treating high-flow vascular malformations of the head and neck region. In the patient with high-flow arteriovenous malformation of the lower lip, superselective catheterization was performed under general anesthesia. The microcatheter was used to administer 750 IU BLM intra-arterially into the feeding vessel. The whole malformation surface was then covered with 15 applications of electric pulses using the plate electrode. Excellent response, without functional or aesthetic deficits, was obtained in 10 weeks. During this period, debridement and necrectomy were performed regularly on follow-up visits. The pain was managed with oral paracetamol and sodium metamizole. Combining electrochemotherapy using bleomycin with superselective catheterization and arteriography is a feasible treatment option for high-flow vascular malformations in the head and neck region and could play a significant role in managing these challenging lesions.

A study of duplex ultrasound examination in peripheral vascular malformations

Vascular malformations belong to wide spectrum of disease involving all vascular segments- arteries, veins as well as lymphatics. Being Ultrasound as the primary diagnostic modality, all peripheral vascular malformation diagnosis can be made by clinical examination and duplex ultrasound examination.A study of 50 patients was carried over a period of 1 year from 1 May 2021 to 1 May 2022 on the patient who came with complain of slow growing, superficial swelling which is painless in nature. The machine used is Affinity Philips 70 G.With help of duplex ultrasound, various types of vascular malformations were diagnosed with incidence such as Slow Flow Venous malformation (60%- 30 patients), High flow Arterio-venous malformations (16%- 8 patients), Capillary malformations (12%- 6 patients) and Lymphatic malformations (12%- 6 patients).Vascular malformations have been classified into venous, arterial, capillary, combined and lymphatic malformations types. Besides age presentations, detailed history and clinical examination, ultra-sound imaging plays an important role in correct diagnosis and classification of vascular malformations. It assesses exact flow dynamics in order to differentiate between Slow flow v/s High flow vascular malformations. MRI is most valuable diagnostic tool for comprehensive assessment of vascular malformationsUltrasound are first imaging modality in peripheral vascular malformations. It has plays crucial role in proper treatment planning of the lesion as it describes the extent, type, flow pattern within the lesion.

Study of Safety and Efficacy of Endovascular Management of High-Flow Arteriovenous Malformation

Study of Safety and Efficacy of Endovascular Management of High-Flow Arteriovenous Malformation

MULTIDISCIPLINARY APPROACH TO TREATMENT OF HIGH FLOW HEAD AND NECK ARTERIOVENOUS MALFORMATIONS: SINGLE CENTRE EXPERIENCE IN 7 COMPLEX CASES

Introduction: The objective of this work is to determine the role of a multidisciplinary approach in treating the complex high flow head and neck arteriovenous malformations (AVMs), involving radiologists and plastic surgeons for the best possible outcomes. Methods: Between 2018 and 2020, the investigators conducted a retrospective analysis on seven patients with high-flow head and neck AVMs who received treatment at a tertiary care facility. Age at first diagnosis, presenting features, prior therapies, endovascular treatment, surgical treatment, and therapeutic outcomes were all recorded. A comparison of pre-and post-procedure pictures was made to assess the clinical outcomes for all patients. Results: Seven patients with complex high flow head and neck AVMs were jointly managed by performing plastic surgery and interventional radiology. There were male and female, with an average age of 24 years. Each patient underwent embolization followed by surgical resection within a 24-hour window of up to 72 hours. In six out of seven patients, the lesion was removed therapeutically, whereas the seventh required palliative resection. Only one patient, there was a minor wound healing difficulty able to be treated with dressings. Conclusion: The results revealed that embolization alone is not effective to reduce the adverse effects. Incomplete removal of AVM showed the same effect as incomplete removal of a tumour. It may not improve symptoms and may worsen the recurrence, thus multi-modality approach is beneficial. A multidisciplinary approach, aided by the interventional radiologist and enable plastic surgeons to remove the high-flow AVMs effectively.

Preoperative flow analysis of arteriovenous malformations and obliteration response after stereotactic radiosurgery.

Morphological and angioarchitectural features of cerebral arteriovenous malformations (AVMs) have been widely described and associated with outcomes; however, few studies have conducted a quantitative analysis of AVM flow. The authors examined brain AVM flow and transit time on angiograms using direct visual analysis and a computer-based method and correlated these factors with the obliteration response after Gamma Knife radiosurgery. A retrospective analysis was conducted at a single institution using a prospective registry of patients managed from January 2013 to December 2019: 71 patients were analyzed using a visual method of flow determination and 38 were analyzed using a computer-based method. After comparison and validation of the two methods, obliteration response was correlated to flow analysis, demographic, angioarchitectural, and dosimetric data. The mean AVM volume was 3.84 cm3 (range 0.64-19.8 cm3), 32 AVMs (45%) were in critical functional locations, and the mean margin radiosurgical dose was 18.8 Gy (range 16-22 Gy). Twenty-seven AVMs (38%) were classified as high flow, 37 (52%) as moderate flow, and 7 (10%) as low flow. Complete obliteration was achieved in 44 patients (62%) at the time of the study; the mean time to obliteration was 28 months for low-flow, 34 months for moderate-flow, and 47 months for high-flow AVMs. Univariate and multivariate analyses of factors predicting obliteration included AVM nidus volume, age, and flow. Adverse radiation effects were identified in 5 patients (7%), and 67 patients (94%) remained free of any functional deterioration during follow-up. AVM flow analysis and categorization in terms of transit time are useful predictors of the probability of and the time to obliteration. The authors believe that a more quantitative understanding of flow can help to guide stereotactic radiosurgery treatment and set accurate outcome expectations.

Endovascular Treatment of a Giant Renal Artery Aneurysm with High-Flow Renal Arteriovenous Malformation

Renal artery aneurysms (RAAs) are rare lesions with a prevalence of less than 1% in the general population. Renal arteriovenous malformations (AVMs) are rare lesions with an estimated incidence of less than 0.04%. The coexistence of these two clinical entities is extremely rare and narrows the available treatment options by endovascular or open surgery. We describe a case of a giant symptomatic RAA type III, which was combined with a high-flow renal AVM in the right kidney. Using two vascular plugs, the RAA was excluded successfully. The perfusion of the right kidney’s lower pole was preserved by implantation of two covered stents in the inferior segmental renal artery.

Is malignant edema and hemorrhage after occlusion of high-flow arteriovenous malformation related to the size of feeding arteries and draining veins?

ObjectiveOur study aimed to identify predictive factors for malignant post-treatment edema and hemorrhage in patients who underwent microsurgical treatment of arteriovenous malformation (AVM) in our institution. MethodsThe study included 72 patients treated by microsurgery for cerebral symptomatic and/or ruptured AVM between 2010 and 2020. Six patients developed postprocedural malignant edema and hemorrhage (group M); the other 66 patients had no malignant edema and hemorrhage (group NM). In each patient, flow was assessed indirectly by summing the diameters of all feeding arteries to obtain an overall diameter (ODA), and similarly for draining veins (ODV). High-flow was defined as a delay between feeding artery injection and draining vein injection (DAV)<1 second on dynamic digital subtraction angiography. Univariate analysis was performed. ResultsMean ODA and ODV were respectively 11mm (±8.2) and 11mm (±5.3) in group M and 2.9mm (±1.4) and 3.7mm (±1.3) in group NM (P=0.001). High-flow AVM was demonstrated in 4 out of 5 patients (85%) in group M and in 14 out of 55 (25%) in group NM (P=0.02). Associated aneurysm was seen in 5 patients in group M (83%) and in 11 in group NM (17%) (P=0.001). ConclusionHigh-flow AVM may be associated with higher risk of postoperative edema and hemorrhage. Multidisciplinary discussion is mandatory in these cases, to define a pre-therapeutic plan for progressive staged vascular malformation occlusion.

Perfusion management during cardiopulmonary bypass in a patient with high cardiac output due to arteriovenous malformations.

We present a case of a 37-year-old woman diagnosed with Parkes-Weber syndrome characterized by high-flow arterio-venous malformations of the pelvic region with an estimated cardiac output of 7.2-8.5 l/min. Due to concomitant Marfan syndrome, the patient also presented an aortic root aneurysm needing surgical treatment under cardiopulmonary bypass. Concerns arose regarding the ability to maintain sufficient perfusion pressure during cardiopulmonary bypass due to the arterio-venous malformations. To address this, an intravascular balloon occlusion at the level of the aortic bifurcation was placed in order to limit arterial inflow into the arterio-venous malformations and achieve optimal perfusion pressure during cardiopulmonary bypass. The patient did not experience any complications and recovered completely after surgery.

Combined Treatment of High-Flow Scalp Arteriovenous Malformations.

Appropriate treatment of scalp arteriovenous malformations (SAVMs) remains largely unclear given the rarity of reported cases. This single-institution case series presents consecutive patients with extracranial SAVMs and long-term follow up.The primary aim of this study was to review treatment decisions, evaluate clinical outcomes, and compare our experience to available literature in order to better understand SAVMs and improve future outcomes. A retrospective review of consecutive patients with extracranial SAVMs between January 2015 and December 2019 was performed. Treatment factors of interest included embolization method, embolic agents, and decision to proceed with surgical resection. Relevant clinical outcomes included recurrence rates, cure rates, and complications. Seven patients were included in the present series. Satisfactory outcomes were ultimately achieved for all 7 patients using embolization with or without combined surgical resection. Embolizations performed in combination with resection were curative in 4 of 4 cases (100%). Embolizations performed without resection were curative in 0 of 4 cases (0%), satisfactory in 2 of 4 cases (50%), and unsatisfactory in 2 of 4 cases (50%). All SAVM patients in this series were treated satisfactorily using embolization with or without operative resection. This study strongly suggests that embolization combined with surgical resection during the same admission yields the best treatment outcomes for SAVMs, specifically demonstrating lower rates of recurrence and embolization-related complications. Decisions on whether or not to proceed with resection should be made by the interventional radiologist, the plastic surgeon, and the patient together.

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

PurposeTo 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 MethodsThis 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. ResultsThe 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. ConclusionsIn 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.

Adenosine-induced Asystole during AVM Embolization

BackgroundAdenosine induced cardiac standstill has been used intraoperatively for both aneurysm and arteriovenous malformation (AVM) surgery and embolization. We sought to report the results of adenosine induced cardiac standstill as an adjunct to endovascular embolization of brain AVMs.Material and MethodsWe retrospectively identified patients in our prospectively maintained database to identify all patients since January 2007 in whom adenosine was used to induce cardiac standstill during the embolization of a brain AVM. We recorded demographic data, clinical presentation, Spetzler Martin grade, rupture status, therapeutic intervention and number of embolization sessions, angiographic and clinical results, clinical and radiological outcomes and follow-up information.ResultsWe identified 47 patients (22 female, 47%) with average age 42 ± 17 years (range 6–77 years) who had undergone AVM embolization procedures using adjunctive circulatory standstill with adenosine. In total there were 4 Spetzler Martin grade 1 (9%), 9 grade 2 (18%), 15 grade 3 (32%), 8 grade 4 (18%), and 11 grade 5 (23%) lesions. Of the AVMs six were ruptured or had previously ruptured. The average number of embolization procedures per patient was 5.7 ± 7.6 (range 1–37) with an average of 2.6 ± 2.2 (range 1–14) embolization procedures using adenosine. Overall morbidity was 17% (n = 8/47) and mortality 2.1% (n = 1/47), with permanent morbidity seen in 10.6% (n = 5/47) postembolization. Angiographic follow-up was available for 32 patients with no residual shunt seen in 26 (81%) and residual shunts seen in 6 patients (19%). The angiographic follow-up is still pending in 14 patients. At last follow-up 93.5% of patients were mRS ≤2 (n = 43/46).ConclusionAdenosine induced cardiac standstill represents a viable treatment strategy in high flow AVMs or AV shunts that carries a low risk of mortality and permanent neurological deficits.

Transcatheter Embolo-sclerotherapy of High Flow Arteriovenous Malformations

Background: Vascular malformations can be classified according to endothelial characteristics and flow dynamics of the lesions, on which the principles of treatment are based. Percutaneous injection of sclerosing agents such as ethanol or sodium tetradecyl sulfate is the mainstay treatment for the more prevalent low-flow or venous vascular malformations. In contrast, symptomatic high-flow arteriovenous malformation (AVM) generally requires transcatheter embolo-sclerotherapy with or without surgery to control the disease process. Objective: To evaluate the safety and efficacy of endovascular management of high flow arteriovenous malformation by embolization and sclerotherapy. Patients and methods: This study was conducted at Mansoura University Hospitals, we included a total of 18 cases diagnosed with high flow AVM. All cases were subjected to complete history taking, thorough physical examination, and routine laboratory investigations. Also, duplex ultrasound (US) and computed tomography (CT) angiography were ordered for all cases. Results: The mean age of the included cases was (26.73 years (range, 8 – 60 years). Males represented 61.11% of these cases, while the remaining patients were females. As regard the clinical result, success was achieved in 16 cases (61.11%). Only two cases had poor clinical result (11.11%). Transient ischemia was encountered in 2 cases (11.11%). Other complications included ulceration (5.56%), foot gangrene (5.56%), hand ischemia with amputation (5.56%), contracture scar (5.56%), and necrosis with transient PE (6.7%). With a mean follow up period of 26 months (range, 6 – 36 months), 16 cases showed very good outcome (88.89%), one case had good outcome (5.56%), while the remaining case had poor outcome (5.56%). Conclusion: Embolo-sclerotherapy appears to be safe and effective intervention for high flow arteriovenous malformations.

Diode laser for the treatment of a high flow lip vascular malformation.

About 50% of vascular malformations are located at the head and neck region where they can usually be associated with functional and/or aesthetic limitations. Laser treatment has proven to be effective in treatment of small low-flow vascular malformations, but little is known about the use of this therapy for high-flow larger arteriovenous malformations (AVMs). A congenital high-flow vascular malformation of the upper lip had to be treated because it was causing functional impairment and deformity which were affecting the quality of life. The mainstay of treatment is surgical therapy after embolization of the lesion, but the treatment of high-flow lesions is difficult because of the high risk of mortality and morbidity. The lesion was then treated with transmucosal diode laser applications in multiple sessions. The lesion progressively reduced in dimension without any sign of recurrence after multiple sessions of transmucosal diode laser applications. The clinical examination and the ultrasound scan performed four years after the last treatment demonstrated that no complications or further recurrence occurred. Multiple sessions of diode laser application can be a safe, effective and minimally-invasive treatment for oral mucosa vascular malformations, even if characterized by high flow.