Arteriovenous malformations

Treatment Effectiveness and Recurrence of Extracranial Arteriovenous Malformations Following Surgical Operations: A 15-Year Retrospective Cohort Study

BACKGROUND

At present, there is no golden standard for treatment of extracranial arteriovenous malformations (AVMs) and recurrence remains a major challenge with limited available evidence on the associated factors. This study aimed to evaluate the effectiveness of surgical treatment options, in terms of size reduction, symptoms, and early recurrence in patients treated surgically for AVMs.

METHODS

A retrospective cohort study was conducted to evaluate patients with AVMs following surgical treatment in 2 centers from 2005 to 2020. Posttreatment lesion size and symptoms, as well as recurrence, were assessed. Multiple regression analysis was performed to identify factors associated with recurrence.

RESULTS

Forty-four surgical treatment cases in 31 patients were assessed with a mean follow-up duration period of 67.9 ± 39.5 months. Treatment included total resection in 26 cases (59.1%) and partial resection 18 (40.9%), with free flap coverage used in 19 cases (43.2%). No acute exacerbation following treatment was observed in our cohort. Total resection significantly reduced posttreatment lesion size ( P < 0.001), symptoms ( P < 0.001), and recurrence (20.0%, P = 0.03). The recurrence rate was significantly higher after partial resection (73.7%, P = 0.03). Total resection was identified as an associated factor for significantly reduced AVM recurrence (odds ratio: 0.12; 95% confidence interval: 0.03, 0.52). However, the use of free flaps did not significantly reduce recurrence, post treatment size or improve AVM symptoms.

CONCLUSIONS

Total resection is the optimal treatment for AVMs. Free flaps are useful in covering large defects but the regulative effect of free flap remains controversial.

[Management of pediatric vascular malformations]

BACKGROUND

Vascular malformations belong to the group of vascular anomalies. They are rare congenital diseases resulting from abnormal development of vessels and can arise in any location, often in the head and neck region. Clinical symptoms are variable, functional handicaps and esthetic problems may result.

MATERIALS AND METHODS

One differentiates between arteriovenous, lymphatic, venous, and capillary malformations and combinations thereof. Their classification, symptoms, diagnostics, and treatment options are discussed.

RESULTS

The different types of vascular malformations as well as their clinical presentation, diagnostic workup, and therapeutic options are presented, supported by clinical examples.

CONCLUSION

Interdisciplinary care of pediatric patients with vascular malformations is essential in order to generate a treatment concept after correct diagnosis and improve symptoms and quality of life.

Scrotal arteriovenous malformation (AVM) successfully resected without angioembolization: A case report

INTRODUCTION AND IMPORTANCE

The main types of scrotal vascular lesions are varicocele, hemangioma, lymphangioma and arteriovenous malformation (AVM). AVM consists of network between arteries and veins without capillaries. It is the rarest type especially when in scrotum.

CASE PRESENTATION

A 24-year-old male patient presented with a skin deformity and painless swelling in the left scrotum. Physical examination revealed this swelling that extended to the inguinal region. Duplex Ultrasound (DUS) followed by Multi-slice Computed Tomography (MSCT) were performed to establish the diagnosis. Management depended on surgical excision without angioembolization. Preoperative sperm analysis showed oligoasthenozoospermia that improves significantly after treatment and 1 year of follow-up.

CLINICAL DISCUSSION

Surgical resection of scrotal AVM without embolization has been used in very few cases and has resulted in a satisfactory outcome with no signs of recurrence throughout the follow-up period.

CONCLUSION

Based on our experience, surgical excision without embolization is a reasonable alternative approach to treat scrotal AVM in low-income countries alongside avoiding the negative consequences of radiation therapy. Treatment should be considered when fertility is affected.

Pediatric Vascular Anomalies: A Clinical and Radiological Perspective

According to the International Society for the Study of Vascular Anomalies (ISSVA) classification, vascular anomalies include a diverse range of pathologies, classified as either vascular tumors or vascular malformations. This classification, last revised in 2018, aims to explain the biological basis of vascular lesions and help clinicians to manage the anomalies. In vascular tumors, there are proliferative changes of endothelial cells, while vascular malformations primarily consist of structural vascular abnormalities. Infantile hemangioma is the most common soft-tissue vascular tumor. Vascular malformations are an extensive group of malformations of the arterial, venous, and lymphatic systems, either in isolation or in combination. Radiological evaluation plays a key part in the management of pediatric patients with these entities. The understanding of sonography and magnetic resonance imaging findings entails its correlation with clinical findings at the time of scanning.

Patient characteristics and disease spectrum in a German vascular anomalies center

BACKGROUND

Vascular malformations are rare diseases that should be treated in dedicated vascular anomaly centers (VAC). There is only a small amount of data on the diagnostic and therapeutic handling of these patients, before they are referred to a VAC.

PURPOSE

To demonstrate the disease-specific patient characteristics in a German VAC, which are required to determine diagnostic and therapeutic steps.

MATERIAL AND METHODS

In a retrospective study, all patients who were treated in the VAC from April 2014 until August 2021 were identified. In total, 593 patients were included in this study.

RESULTS

Almost all patients had previously consulted a physician (591/593, 99.7%). A mean of two different physicians had been consulted (range 0-10). Patients with more complex, syndromal vascular malformations had significantly more previous appointments (P = 0.0018). In only 44% (261/593) of patients, the referral diagnosis was made correctly. Most patients had been previously treated for their vascular anomaly: pharmacotherapy (n = 130; 21.9%), compression garments (n = 141; 23.8%), surgical resection (n = 80; 17.3%) and sclerotherapy (n = 68; 11.5%). Fifty-two patients who had been falsely diagnosed had also received therapy prior to their referral to the VAC (8.8%). Most patients received an ultrasound examination in the VAC (n = 464; 78.2%). Most frequently, compression therapy was prescribed (n = 256; 43.2%), followed by sclerotherapy (n = 175, 29.5%) and pharmacotherapy (n = 55; 9.3%).

CONCLUSION

Patients suffering from vascular anomalies often go through a complicated scheduling with numerous outpatient appointments and have a high risk of misdiagnosis and mistreatment prolonging the medical condition. Therefore, patients with vascular anomalies should be treated in a dedicated vascular anomaly center.

Ethanol Embolotherapy for Cutaneous Erythema of High-Flow Vascular Malformations in the Head and Neck

BACKGROUND

Cutaneous erythema is one of the most common signs of arteriovenous malformations (AVMs) in the head and neck region, influencing aesthetic appearance. Surgical resection of AVMs may lead to cicatrization of the skin or aggravation of the lesion. Laser treatment, although effective in improving superficial vascular lesions, cannot prevent deep AVMs from further development.

OBJECTIVE

The authors propose an absolute ethanol embolization therapy that can effectively and safely eradicate the nidus with a favorable aesthetic outcome.

METHODS

The authors conducted a retrospective observational study of 14 AVM patients with distinct cutaneous erythema in the head and neck region undergoing embolotherapy in a single primary care center. Symptoms before and after treatment, complications, and degree of devascularization were recorded and assessed. Changes in cutaneous redness were evaluated using a previously reported quantitative measurement.

RESULTS

Complete symptomatic relief was observed in 5 patients, and major improvement was observed in 9 patients. The mean Δ a * value of the color change had a significant reduction of 6.50 ± 4.04, p < .001, indicating a remarkable remission of cutaneous erythema.

CONCLUSION

Ethanol embolization is an effective and safe treatment for head and neck AVMs with excellent aesthetic outcomes and might become a potential treatment method for other superficial vascular anomalies.

The Role and Therapeutic Implications of Inflammation in the Pathogenesis of Brain Arteriovenous Malformations

Brain arteriovenous malformations (bAVMs) are focal vascular lesions composed of abnormal vascular channels without an intervening capillary network. As a result, high-pressure arterial blood shunts directly into the venous outflow system. These high-flow, low-resistance shunts are composed of dilated, tortuous, and fragile vessels, which are prone to rupture. BAVMs are a leading cause of hemorrhagic stroke in children and young adults. Current treatments for bAVMs are limited to surgery, embolization, and radiosurgery, although even these options are not viable for ~20% of AVM patients due to excessive risk. Critically, inflammation has been suggested to contribute to lesion progression. Here we summarize the current literature discussing the role of the immune system in bAVM pathogenesis and lesion progression, as well as the potential for targeting inflammation to prevent bAVM rupture and intracranial hemorrhage. We conclude by proposing that a dysfunctional endothelium, which harbors the somatic mutations that have been shown to give rise to sporadic bAVMs, may drive disease development and progression by altering the immune status of the brain.

Current concepts of vascular anomalies

Vascular anomalies encompass a variety of malformations and tumors that can result in severe morbidity and mortality in both adults and children. Advances have been made in the classification and diagnosis of these anomalies, with the International Society for the Study of Vascular Anomalies establishing a widely recognized classification system. In recent years, notable progress has been made in genetic testing and imaging techniques, enhancing our ability to diagnose these conditions. The increasing sophistication of genetic testing has facilitated the identification of specific genetic mutations that help treatment decisions. Furthermore, imaging techniques such as magnetic resonance imaging and computed tomography have greatly improved our capacity to visualize and detect vascular abnormalities, enabling more accurate diagnoses. When considering reconstructive surgery for facial vascular anomalies, it is important to consider both functional and cosmetic results of the procedure. Therefore, a comprehensive multidisciplinary approach involving specialists from dermatology, radiology, and genetics is often required to ensure effective management of these conditions. Overall, the treatment approach for facial vascular anomalies depends on the type, size, location, and severity of the anomaly. A thorough evaluation by a team of specialists can determine the most appropriate and effective treatment plan.

Lower-Extremity Arteriovenous Malformation Masquerading as Peripheral Artery Disease

An arteriovenous malformation (AVM) refers to an anomalous, direct connection between an artery and a vein. Typically, these two vessels are interposed by high-resistance capillary beds, the absence of which results in a high-flow system from an artery into a vein. Venous vessel walls are not designed to handle such high-pressure blood flow, and their vessel wall structure becomes permanently altered and weakened. For this reason, AVMs are at an increased risk for hemorrhages and ruptures. AVMs present with a spectrum of symptoms, ranging from skin discoloration, ischemia in distal tissues, and heart failure from arteriovenous shunting. Here, we present a case of a patient who underwent amputation of his second left toe, initially thought to be a result of peripheral arterial disease (PAD) due to his extensive smoking history. Further imaging findings revealed a rare lower-extremity AVM as the source of his ischemia, not PAD. Ultimately, the treatment of the vascular anomaly and resolution of the patient's symptoms were achieved via transarterial embolization. This case emphasizes the importance of looking beyond PAD as the cause of distal lower-extremity ischemia and provides insights into an uncommon and often missed diagnosis of extracranial AVMs.

Radiological Profile of 18,430 Vascular Anomalies: Incidence and Demographic Distribution in an Adult Population

BACKGROUND

Most studies on focusing on the prevalence of vascular anomalies are either aimed to determine the individual occurrence of a specific type among known bearers of abnormalities or propose an estimation of prevalence for the general population by extrapolating from the paediatric population. In this scenario, we intended to assess the profile of vascular anomalies in a group of patients subjected to imaging studies, throughout a long period of time, to evaluate the frequency of abnormal findings in a consecutive, nonselected population.

METHODS

This is a retrospective review of 996,569 computed tomography and magnetic resonance studies between 2009 and 2019. Findings were grouped as vascular tumours (hemangiomas; vascular tumours), cavernomas, and vascular malformations. Positive findings were evaluated with regard to patients' demographic characteristics and anatomic distribution and the subset of vascular malformations was also evaluated with regard to size, classification in accordance to flow pattern, and Hamburg Classification.

RESULTS

Eighteen thousand four hundred thirty positive examinations were evaluated (mean age, 55.82 ± 15.43 years; 8,188 men). Vascular anomalies were present in 18.49 per 1,000 examinations (17.41 hemangiomas; 0.69 cavernomas and 0.39 vascular malformations per 1,000 examinations). Hemangiomas and cavernomas were homogeneous in anatomic location between sexes throughout the age groups. Complex malformations were heterogeneous in anatomic distribution between the sexes in each age group, with intracranial findings decreasing for female patients in older groups.

CONCLUSIONS

Vascular anomalies were found in 18.49 per 1,000 examinations. Hemangiomas and cavernomas were homogenously distributed, whereas complex malformations displayed a heterogeneous anatomic distribution pattern between sexes in each age group.

Vascular anomalies: diagnostic features and step-wise approach

The first part of this review article emphasized correct nomenclature, classification systems, and imaging algorithm of vascular anomalies. The second part of the review discusses the individual entities, highlighting the characteristic clinico-radiological features of the commonly encountered ones. A step-wise algorithmic approach is also proposed for the evaluation of a suspected case of vascular anomaly.

Shoulder Pain Associated With Multiple Arteriovenous Malformations Successfully Treated With Embolization

A 44-year-old male presented with left upper extremity and shoulder pain with worsening functional impairment after years of repetitive use, overtraining, and multiple injuries from weightlifting and mixed martial arts. Imaging showed no obvious injury or ligamentous deformity other than mild osteoarthritis (OA) of the left glenohumeral joint. Duplex ultrasonography (US) revealed four arteriovenous malformations (AVMs) surrounding the shoulder joint and left upper extremity. The vasculature was mapped via angiography through a transradial approach. Initial treatment included transarterial embolization of two AVMs off the axillary artery and branching anterior circumflex humeral artery. Secondary treatment included embolization of two lesions months later via direct puncture, one through a transvenous approach and the second through direct transmalformation cannulation, via the nidus, near the clavicle and posterior scapular lateral border. Treatment resulted in significant improvement in pain and range of motion. Follow-up assessments revealed improvement in overall symptoms, recovered function, and return to exercise and competitive mixed martial arts. This case highlights the value of duplex ultrasonography, embolization, and transarterial and transvenous approaches for the treatment of AVM-associated extremity or joint pain.

Recurrent head and neck arteriovenous malformations: A case report

Head and neck arteriovenous malformations are rare, congenital, and high-flow vascular malformations characterized by abnormal communication between feeding arteries and draining veins without intervening capillaries. Arteriovenous malformations are considered the most dangerous type of vascular malformation because progressive symptoms and infiltration can result in potentially life-threatening consequences. Left untreated, arteriovenous malformations can cause significant cosmetic deformities, severe bleeding, and high-output cardiac failure associated with arteriovenous shunting. The effective treatment of arteriovenous malformations located in the head and neck region is quite challenging due to high rates of recurrence and potentially lethal complications. We describe a case presenting with large arteriovenous malformations in the face and neck. Despite attempting several treatments, including external carotid artery ligation and embolization with liquid embolic agents, the patient continued to experience recurrence and symptoms of bleeding and pain. After admission, reconstructive plastic surgery was performed, supplemented by percutaneous direct puncture embolization, using glue injected into the venous and transarterial embolization. The patient was discharged with clinical recovery. Digital subtraction angiography remains the gold standard for assessing symptomatic and aggressive arteriovenous malformations, both before and after treatment. The treatment of head and neck arteriovenous malformations often requires a multidisciplinary approach to achieve the best clinical results.

Vascular malformation rupture in a patient affected by Costello syndrome

Costello syndrome (CS) is a rare genetic syndrome affecting multiple organs, generally caused by mutations of the HRAS gene, belonging to the RAS/MAPK genes family.A male patient with CS developed a painful pulsatile mass on the lateral side of the wrist. An initial ultrasonographic investigation confirmed the presence of a radial artery lesion, possibly an arterial aneurysm. On surgical resection, histological evaluation showed a tangle of vascular structures with variable calibre and abnormal wall histology. Immunohistochemical stainings revealed a very poor endothelial contribution to the central vascular wall structure. These histological observations led us to conclude we had managed an acute vascular malformation (VM) rupture, rather than a common arterial aneurysmal condition. Considering the molecular mechanisms regulated by RAS/MAPK genes, CS patients might have a higher risk of developing VMs and, in the presence of a pulsatile mass with acute onset, VM rupture should be considered.

Multimodality Treatment of Vascular Anomalies of The Head And Neck

Vascular anomalies affect up to 5% of children with the majority affecting the head and neck. They present at different ages as a wide variety of lesions. Careful evaluation with history, physcial examination and imaging assist in the proper diagnosis. Depending on the condition, treatment options for vascular anomalies include topical therapy, selective photothermolysis, sclerotherapy, embolization, surgical excision and targeted systemic therapy. Staged multimodal therapeutic regimens have proven to best control disease and allow for preservation of function and aesthetics. The timing, sequence and combination of therapies is best determined by a multidisciplinary vascular anomalies team. Patients and families need to be counseled on anticipated positive outcomes following a protracted course of treatment for the majority of vascular anomalies.

Neonatal vascular anomalies manifesting as soft-tissue masses

The broad and heterogeneous spectrum of vascular anomalies ranges from an innocuous localized cutaneous discoloration to complex, extensive and life-threatening diagnoses. While many of these lesions are present at birth, smaller and deeper lesions might be clinically occult for months or years. Certain vascular anomalies commonly manifest in the prenatal or neonatal period and often have suggestive clinical and imaging features that can aid the radiologist in making a correct diagnosis. The characteristics of such lesions presenting very early in life, particularly those manifesting as soft-tissue masses, are the focus of this review.

Surgical management of auricular arteriovenous malformations: A literature review

Auricular arteriovenous malformations (AVMs) can cause a variety of symptoms that seriously impact the patient's appearance, life, and mental well‐being. Surgery is the primary management method for auricular AVMs, but there is no consensus on how to surgically manage auricular AVMs. In this article, we document a comprehensive review of the characteristics, classification, and surgical interventions to treat auricular AVMs.

Somatic Mutational Landscape of Extracranial Arteriovenous Malformations and Phenotypic Correlations

BACKGROUND

Somatic genetic variants may be the cause of extracranial arteriovenous malformations, but few studies have explored these genetic anomalies, and no genotype-phenotype correlations have been identified.

OBJECTIVES

To characterize the somatic genetic landscape of extracranial arteriovenous malformations and correlate these findings with the phenotypic characteristics of these lesions.

METHODS

This study included twenty-three patients with extracranial arteriovenous malformations that were confirmed clinically and treated by surgical resection, and for whom frozen tissue samples were available. Targeted next-generation sequencing analysis of tissues was performed using a gene panel that included vascular disease-related genes and tumor-related genes.

RESULTS

We identified a pathogenic variant in 18 out of 23 samples (78.3%). Pathogenic variants were mainly located in MAP2K1 (n=7) and KRAS (n=6), and more rarely in BRAF (n=2) and RASA1 (n=3). KRAS variants were significantly (p<0.005) associated with severe extended facial arteriovenous malformations, for which relapse after surgical resection is frequently observed, while MAP2K1 variants were significantly (p<0.005) associated with less severe, limited arteriovenous malformations located on the lips.

CONCLUSIONS

Our study highlights a high prevalence of pathogenic somatic variants, predominantly in MAP2K1 and KRAS, in extracranial arteriovenous malformations. In addition, our study identifies for the first time a correlation between the genotype, clinical severity and angiographic characteristics of extracranial arteriovenous malformations. The RAS/MAPK variants identified in this study are known to be associated with malignant tumors for which targeted therapies have already been developed. Thus, identification of these somatic variants could lead to new therapeutic options to improve the management of patients with extracranial arteriovenous malformations.

CTRP9 Mitigates the Progression of Arteriovenous Shunt-Induced Pulmonary Artery Hypertension in Rats

The present study is aimed at investigating the molecular mechanism of C1q/TNF-related protein 9 (CTRP9) and providing a new perspective in arteriovenous shunt-induced pulmonary arterial hypertension (PAH). PAH was established by an arteriovenous shunt placement performed in rats. Adenovirus(Ad)-CTRP9 and Ad-green fluorescent protein viral particles were injected into the rats through the tail vein. Following 12 weeks, the mean pulmonary arterial pressure (mPAP) and right ventricular systolic pressure (RVSP) were measured and morphological analysis was conducted to confirm the establishment of the PAH model. The systemic elevation of CTRP9 maintained pulmonary vascular homeostasis and protected the rats from dysfunctional and abnormal remodeling. CTRP9 attenuated the pulmonary vascular remodeling in the shunt group by decreasing the mPAP and RVSP, which was associated with suppressed inflammation, apoptosis, and extracellular matrix injury. In addition, CTRP9 dramatically increased the phosphorylation of AKT and p38-MAPK in the lung tissues of shunt-operated animals. These findings suggest a previously unrecognized effect of CTRP9 in pulmonary vascular homeostasis during PAH pathogenesis.

Stereotactic Body Radiotherapy (SBRT) for an Extracranial Arteriovenous Malformation of the Pelvis

Extracranial arteriovenous malformations (AVMs) are rare pathological, benign conditions that are characterized by aberrantly connected arteries and veins without normal intervening capillary vasculature. Although stereotactic radiosurgery is an established, efficacious, safe treatment for intracranial AVMs, there is no known published data on the use of stereotactic body radiotherapy (SBRT) for the treatment of abdominopelvic AVMs. One patient with an extracranial AVM in the pelvis that was only partially responsive to embolization was treated with SBRT to a dose of 21 Gy, delivered in three fractions over six calendar days. At presentation, the patient was non-ambulatory due to neuropathic pain from a sciatic impingement of the AVM. The patient underwent two prior catheter-based embolization procedures that had achieved partial obliteration, but with the persistence of neuropathic pain and symptoms. After SBRT to the pelvic AVM, the patient had marked improvement in pain over 10 months and was able to ambulate again. Follow-up angiography and CT demonstrated the obliteration of previously visualized AVM. We describe the first known report of pelvic AVM successfully treated with a combination of embolization and SBRT. Three-fraction SBRT to a total dose of 21 Gy appears to be safe and effective for extracranial AVMs arising in the pelvis. This strategy may be considered for patients with pelvic AVMs that are refractory to standard interventional therapies. However, these findings should be validated in larger cohorts.

Endovascular embolization for managing a massive shoulder arteriovenous malformation

Arteriovenous malformations (AVMs) are congenital high flow pathologic linkages between arteries and veins of different sizes that may occur in any part of the body. The clinical presentation is largely dependent on the size and location of AVMs and can range from an asymptomatic birthmark to congestive heart failure in extreme cases. In this report, we describe a 20-year-old male who presented with a large AVM of the right shoulder that resulted in significant cosmetic and physical impairment and treated with several sessions of endovascular embolization with good clinical outcomes. This case highlights the complexity of diagnosing and managing these AVMs. Most of these anomalies require a multi-disciplinary approach that integrates both trans-catheter and surgical interventions with trans-arterial lesion embolization being the cornerstone of the treatment.

A Rare Cause of Post-traumatic Right Lower Extremity Swelling in an Adolescent Male

Unilateral extremity swelling after trauma usually results from acute musculoskeletal or orthopedic injuries. Worsening of swelling raises concern for compartment syndrome or vascular injury. Time-sensitive diagnosis and interventions are needed to avoid life- or limb-threatening consequences. In this report, we highlight the case of a 16-year-old male who presented with unilateral lower extremity pain and swelling, one week after a motor vehicle accident. Thorough evaluation and appropriate imaging detected the presence of an abnormal communication between the muscular branch of the anterior tibial artery and the vein. Arteriovenous fistulas (AVFs) are usually acquired and caused by penetrating trauma or iatrogenic procedures. They are rarely associated with blunt trauma. It is important to determine the degree of flow within the communication, as high flow lesions are associated with severe complications such as limb ischemia and heart failure. This report highlights the evaluation and management of a patient with delayed post-traumatic unilateral extremity swelling that eventually resulted in the diagnosis of a low-flow AVF amenable to conservative management, resulting in complete resolution of his symptoms.

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.

Blood Flow and Shear Stress Allow Monitoring of Progression and Prognosis of Tumor Diseases

In the presence of tumor angiogenesis, blood flow must increase, leading to an elevation of blood flow velocities (BFVels) and wall shear stress (WSS) in upstream native arteries. An adaptive arterial remodeling is stimulated, whose purpose lies in the enlargement of the arterial inner diameter, aiming for normalization of BFVels and WSS. Remodeling engages delayed processes that are efficient only several weeks/months after initiation, independent from those governing expansion of the neovascular network. Therefore, during tumor expansion, there is a time interval during which elevation of BFVels and WSS could reflect disease progression. Conversely, during the period of stability, BFVels and WSS drop back to normal values due to the achievement of remodeling processes. Ovarian peritoneal carcinomatosis (OPC), pseudomyxoma peritonei (PMP), and superficial arteriovenous malformations (AVMs) are diseases characterized by the development of abnormal vascular networks developed on native ones. In OPC and PMP, preoperative blood flow in the superior mesenteric artery (SMA) correlated with the per-operative peritoneal carcinomatosis index (OPC: n = 21, R = 0.79, p < 0.0001, PMP: n = 66, R = 0.63, p < 0.0001). Moreover, 1 year after surgery, WSS in the SMA helped in distinguishing patients with PMP from those without disease progression [ROC-curve analysis, AUC = 0.978 (0.902-0.999), p < 0.0001, sensitivity: 100.0%, specificity: 93.5%, cutoff: 12.1 dynes/cm²]. Similarly, WSS in the ipsilateral afferent arteries close to the lesion distinguished stable from progressive AVM [ROC-curve analysis, AUC: 0.988, (0.919-1.000), p < 0.0001, sensitivity: 93.5%, specificity: 95.7%; cutoff: 26.5 dynes/cm²]. Blood flow volume is indicative of the tumor burden in OPC and PMP, and WSS represents an early sensitive and specific vascular marker of disease progression in PMP and AVM.

Pregnancy after percutaneous ethanol sclerotherapy for uterine arteriovenous fistula: Case report

Uterine arteriovenous fistula is a rare but life-threatening gynecologic entity. Meanwhile, long-term radiation exposure will do serious harm to doctors' health. So we improve the operation method to reduce the radiation exposure time. The patient, a 24-years-old woman with a history of dilation and curettage, had long-term menorrhagia and anemia. Uterine arteriovenous fistula was confirmed by ultrasonography and computed tomography angiograph. Percutaneous anhydrous ethanol sclerotherapy was performed under the guidance of the X-ray imaging. The patient was followed up for 2 years without recurrence and had normal menstruation. Recently, she is successfully pregnant again. Percutaneous anhydrous ethanol sclerotherapy is a new option treating uterine arteriovenous fistula, which can greatly shorten the irradiation time and reduce the recurrence rate and has no obvious adverse effect on fertility.

Interdisciplinary management of peripheral arteriovenous malformations: review of the literature and current proceedings

Arteriovenous malformations (AVMs) are a rare congenital vascular disorder. They represent a fast-flow vascular malformation. Clinically, AVMs present a heterogenous expression and can affect every part of the body. Here, we will solely focus on extracranial AVMs. Generally, AVMs progress with the patient's age. Patients often suffer from pulsation, skin discoloration, pain, ulceration, bleeding, and disfigurement. Diagnostic tools include color-coded duplex sonography, MRI and CT imaging, as well as the clinical examination. 4D dynamic perfusion-computed tomography may help in the interventional planning. Digital subtraction angiography is required during interventional therapy. AVMs pose a great challenge to the treating physician. The therapy of this rare disease should be managed in an interdisciplinary center for vascular malformations. It consists of conservative measures, such as compression garments and pain medication, transcatheter or, more rarely, percutanous embolization, and surgical resection. In smaller, localized lesions, resection with primary wound closure may be feasible, whereas extensive AVMs regularly require the reconstruction of the resulting soft tissue defect and possibly affected functional structures by means of free tissue transfer. In the interdisciplinary setting required for an appropriate treatment of AVMs, extensive knowledge of the various therapies, including those from different specialties, is necessary. Therefore, this article aims to provide an overview over both the interventional and surgical therapeutic options.

Effects of serum starvation and vascular endothelial growth factor stimulation on the expression of Notch signalling pathway components

Brain arteriovenous malformation (BAVM) is an abnormality in the cerebral vascular system. Although the upregulation of the Notch signalling pathway is a deterministic factor in BAVM, the mechanism by which this pathway is upregulated in patients with BAVM is uncertain. The effects of serum starvation and vascular endothelial growth factor (VEGF) stimulation on the Notch signalling pathway in brain microvascular endothelial cells (MECs) and mouse embryonic stem (mES)/embryoid body (EB)-derived endothelial cells were investigated in this study. The duration of serum starvation and VEGF concentration were changed, cell viability was measured, and reasonable time and concentration gradients were selected for subsequent studies. Protein and mRNA expression levels of Notch signalling pathway components in both MECs and mES/EB-derived endothelial cells were detected using western blotting and real-time PCR, respectively. Expression levels of the Notch1, Notch4, Jagged1, delta-like ligand 4 (Dll4) and Hes1 proteins and mRNAs were upregulated by lower VEGF concentrations and shorter-term serum starvation but inhibited by higher VEGF concentrations and longer-term serum starvation. This study revealed effects of changes in the duration of serum starvation and VEGF concentration on the expression of Notch signalling pathway components in both MECs and mES/EB-derived endothelial cells, potentially contributing to BAVM formation.

Management of symptomatic adult penile urethral arteriovenous malformation

We present the Case of a 23-year-old male with a history of recurrent spontaneous urethral bleeding due to an arteriovenous malformation (AVM) of his corpus spongiosum which abutted his penile urethra. AVMs are often congenital but can also be related to prior trauma. The literature on male genital AVMs is primarily limited to pediatric AVMs of the scrotum or glans penis with one report of adult urethral AVM in the setting of known trauma. We describe a novel presentation of atraumatic adult male genital AVM treated by surgical repair with resolution of bleeding.

Stemness-Associated Markers Are Expressed in Extracranial Arteriovenous Malformation

Objectives: Arteriovenous malformation (AVM) consists of a nidus with poorly formed low-resistance vessels in place of a functional capillary network. The role of somatic mutations in embryonic stem cells (ESCs) and vascular anomalies and the presence of primitive populations in vascular anomalies led us to investigate the presence of a primitive population in extracranial AVM.

Methods: Extracranial AVM tissue samples from 12 patients were stained for stemness-associated markers OCT4, SOX2, NANOG, KLF4, and c-MYC using immunohistochemical staining. In situ hybridization (ISH) was performed on six tissue samples to determine transcript expression. Western blotting and RT-qPCR were performed on two AVM-derived primary cell lines to determine protein and transcript expression of these markers, respectively. Immunofluorescence staining was performed on two tissue samples to investigate marker co-localization.

Results: Immunohistochemical staining demonstrated the expression of OCT4, SOX2, KLF4, and c-MYC on the endothelium and media of lesional vessels and cells within the stroma of the nidus in all 12 AVM tissue samples. ISH and RT-qPCR confirmed transcript expression of all five markers. Western blotting showed protein expression of all markers except NANOG. Immunofluorescence staining demonstrated an OCT4+/SOX2+/KLF4+/c-MYC+ population within the endothelium and media of the lesional vessels and cells within the stroma of the AVM nidus.

Conclusions: Our findings may suggest the presence of a primitive population within the AVM nidus. Further investigation may lead to novel therapeutic targeting of this population.

Contemporary Management of Vascular Anomalies of the Head and Neck-Part 1: Vascular Malformations: A Review

Importance

Vascular anomalies of the head and neck are relatively rare lesions. Management is challenging because of the high likelihood of involvement of functionally critical structures. Multiple modalities of treatment exist for vascular anomalies of the head and neck, including medical therapies, sclerotherapy and embolization procedures, and surgery. This review focuses on the accurate diagnosis and the relative roles of the various therapeutic options.

Observations

Vascular anomalies are classified by the International Society for the Study of Vascular Anomalies into 2 major groups: vascular tumors and vascular malformations. Vascular tumors encompass proliferative lesions ranging from infantile and congenital hemangiomas to kaposiform hemangioendothelioma. Alternatively, vascular malformations are embryologic errors in vasculogenesis. This article focuses on the management of vascular malformations. The 3 primary vascular malformation subclassifications are lymphatic, venous, and arteriovenous. The burden of disease, diagnosis, and current management options are discussed in detail for each subtype.

Conclusions and Relevance

Most vascular malformations of the head and neck require a multidisciplinary approach. Available medical, interventional radiologic, and surgical interventions are constantly evolving. Optimization of function and cosmesis must be balanced with minimization of treatment-associated morbidity. Otolaryngologists-head and neck surgeons must remain up to date regarding options for diagnosis and management of these lesions.

Vascular anomalies of the head and neck

The head and neck are the most common site of involvement for vascular tumors and malformations, with more than half of all vascular anomalies seen in this region. Lesions in this location can cause significant disfigurement and can be associated with airway obstruction, impairment in vision or hearing, swallowing disorders and hemorrhage. Accurate diagnosis is critical in determining treatment, and interdisciplinary care is essential for optimal management. We review clinical and imaging features that are key to establishing the correct diagnosis, and review treatment modalities, with emphasis on interventional and surgical procedures.

Wall Shear Stress in the Feeding Native Conduit Arteries of Superficial Arteriovenous Malformations of the Lower Face is a Reliable Marker of Disease Progression

PURPOSE

 To assess the prognostic value of the wall shear stress (WSS) measured in the feeding native arteries upstream from facial superficial arteriovenous malformations (sAVMs). Reliable prognostic criteria are needed to distinguish progressive from stable sAVMs and thus support the indication for an aggressive or a conservative management to avoid severe facial disfigurement.

MATERIALS AND METHODS

 We prospectively included 25 patients with untreated facial sAVMs, 15 patients with surgically resected sAVMs and 15 controls. All had undergone Doppler ultrasound examination (DUS) with measurements of inner diameters, blood flow velocities, computation of blood flow and WSS of the feeding arteries. Based on the absence or presence of progression in clinical and imaging examinations 6 months after, we discriminated untreated patients as stable or progressive.

RESULTS

 WSS in the ipsilateral external carotid artery was higher in progressive compared to stable sAVMs (15.8 ± 3.3dynes/cm² vs. 9.6 ± 2.0dynes/cm², mean±SD, p < 0.0001) with a cut-off of 11.5dynes/cm² (sensitivity: 92 %, specificity: 92 %, AUC: 0.955, [95 %CI: 0.789-0.998], p = 0.0001). WSS in the ipsilateral facial artery was also higher in progressive compared to stable sAVMs (50.7 ± 14.5dynes/cm² vs. 25.2 ± 7.1dynes/cm², p < 0.0001) with a cut-off of 34.0dynes/cm² (sensitivity: 100 %, specificity: 92 %, AUC: 0.974, [95 %CI: 0.819-1.000], p = 0.0001). The hemodynamic data of operated patients were not different from those of the control group.

CONCLUSION

 WSS measured in the feeding arteries of an sAVM may be a simple reliable criterion to distinguish stable from progressive sAVMs. This value should be considered to guide the therapeutic strategy as well as the long-term follow-up of patients with facial sAVMs.

Superselective Arterial Embolization of Arteriovenous Malformation of Internal Pudendal Artery, a Rare Cause of Hematuria: A Case Report

Arteriovenous malformation (AVM) is a common form of vascular malformation, an abnormal direct communication between an artery and a vein without passing through the capillaries. AVM may just present as hematuria without plain or other symptoms. The article presents a case of a 52-year-old male with gross hematuria diagnosed as AVM of internal pudendal artery, which was successfully managed with superselective arterial embolization using temporary embolization materials.

Extracranial arteriovenous malformations: from bedside to bench

Arteriovenous malformation (AVM) is defined as a fast-flow vascular anomaly that shunts blood from arteries directly to veins. This short circuit of blood flow contributes to progressive expansion of draining veins, resulting in ischaemia, tissue deformation and in some severe cases, congestive heart failure. Various medical interventions have been employed to treat AVM, however, management of which remains a huge challenge because of its high recurrence rate and lethal complications. Thus, understanding the underlying mechanisms of AVM development and progression will help direct discovery and a potential cure. Here, we summarize current findings in the field of extracranial AVMs with the aim to provide insight into their aetiology and molecular influences, in the hope to pave the way for future treatment.

Spectrum of Imaging Manifestations of Vascular Malformations and Tumors Beyond Childhood: What General Radiologists Need to Know

Vascular anomalies encompass a collection of diagnoses that differ greatly in terms of clinical presentation, natural history, imaging findings, and management. The purpose of this article is to review diagnostic imaging findings of vascular malformations and vascular tumors, excluding the central nervous system, that occur beyond childhood. A widely accepted classification system created by the International Society for the Study of Vascular Anomalies provides a framework for this review, focusing on the entities most likely to be encountered by general radiologists, although several rare but clinically important entities are also reviewed.

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.

Brief Description of ISSVA Classification for Radiologists

Ongoing discovery regarding the origin and treatment of vascular anomalies requires standardized nomenclature which itself must undergo iterative updating. This article introduces the 2018 International Society for the Study of Vascular Anomalies (ISSVA) classification, emphasizing the biologic basis of vascular anomalies, summarizing the key features of commonly encountered entities, and serving as a foundation for subsequent articles presented herein. Vascular tumors are discussed to highlight their distinction from vascular malformations which will receive greater attention with respect to management and technical considerations within the issue.

Up-to-date imaging review of paediatric soft tissue vascular masses, focusing on sonography

The purpose of this article is to provide an up-to-date overview on imaging of paediatric vascular soft tissue masses, including both neoplastic and non-neoplastic lesions. We describe the-often challenging-imaging diagnosis-mainly performed by ultrasound (and secondarily by MRI) and differential diagnosis of vascular soft tissue lesions in children. We underline how important it is to determine whether a vascular anomaly has a regional vascular origin, or if there are other entities, ranging from benign to malignant lesions, which have flow-signal or blood degradation products. Even though clinical examination and patient's history are the first and indispensable steps in the initial diagnosis, the role of imaging is crucial, not only to determine whether a mass represents a true tumour/pseudo-tumour, but also to achieve a more correct diagnosis and determine the extension of the tumour/pseudo-tumour and its relation with the nearby anatomic structures.

Evaluation of dynamic effects of therapy-induced changes in microcirculation after percutaneous treatment of vascular malformations using contrast-enhanced ultrasound (CEUS) and time intensity curve (TIC) analyses

The aim of this follow-up study was to demonstrate the effect of percutaneous interventional treatment on local microcirculation of peripheral vascular malformations using CEUS and TIC analysis.

MATERIAL AND METHODS

Retrospective analysis of 197 patients (136 female; 61 male; 3-86 years) with 135 venous (VM), 39 arterio-venous (AVM), 8 lymphatic and 15 veno-lymphatic peripheral vascular malformations before and after the first percutaneous treatment.CEUS was performed after i.v. injection of 1-2.4 ml of sulfur hexafluoride microbubbles (SonoVue®) using a 6-9 MHz linear probe. Digitally stored cine loops (starting in the early arterial phase for 60 sec) were read by independent readers in consensus. Regions of interest (ROI) were defined in the center and at the margins of the malformation, as well as in the healthy surrounding tissue. TIC analyses with Time to Peak (TTP) and Area under the Curve (AUC) were calculated using integrated perfusion software.

RESULTS

After the treatment there was a significant decrease for median AUC in VM in the center from 297.8 (14.5-2167.6) rU down to 243.3 (0.1-1678.8) rU (p = 0.043) and in the surrounding tissue down to 107.7 (20.2-660.2) rU (p = 0.018). For the other malformations AUC decreased in the center and the margins as well. TTP rose, however these changes did not reach the level of significance.

CONCLUSION

Analyzing the capillary microcirculation TICs offer a possibility of monitoring therapy-induced capillary changes of vascular malformations.

Endovascular treatment of an intraosseous arteriovenous malformation of the mandible in a child. A case Report

The modern application of interventional radiology techniques is revolutionizing the treatment of the vascular malformations of the head and neck. In fact, the morbidity related with the surgical extirpation of the malformation might be drastically reduced with the use of an endovascular approach. The present report describes the case of a 11 years old male affected by a large intraosseous arteriovenous malformation of the mandible. The coil embolization of the main drainage vein caused the spontaneous regression of the lesion and avoided a mutilating surgery and severe psychological sequels. A multidisciplinary approach of these case is mandatory. A careful clinical and radiological study of the patient is essential for a proper management. The choice of the treatment should be based on the location and extension of the malformation, age of the patient, experience with endovascular techniques and clinic. Key words:Endovacualr approach, intraosseous arteriovenous malformation, head and neck, child.

Female Pelvic Vascular Malformations

Vascular malformations are classified primarily according to their flow characteristics, slow flow (lymphatic and venous) or fast flow (arteriovenous). They can occur anywhere in the body but have a unique presentation when affecting the female pelvis. With a detailed clinical history and the proper imaging studies, the correct diagnosis can be made and the best treatment can be initiated. Lymphatic and venous malformations are often treated with sclerotherapy while arteriovenous malformations usually require embolization. At times, surgical intervention of vascular malformations or medical management of lymphatic malformations has been implemented in a multidisciplinary approach to patient care. This review presents an overview of vascular malformations of the female pelvis, their clinical course, diagnostic studies, and treatment options.

Spontaneous Regression of Parapharyngeal Arteriovenous Malformation

Arteriovenous malformations (AVMs) are fast-flow vascular malformations that mostly occur in the head and neck region. They are typically progressive and their spontaneous regression is almost never seen. We present a case with pulsatile tinnitus and a parapharyngeal AVM. It resolved completely after diagnostic catheter-based angiography alone.