Extracranial Arteriovenous Malformations: Natural Progression and Recurrence after Treatment:

Congenital Vascular and Lymphatic Diseases

Over the past several centuries, the integration of contemporary medical techniques and innovative technologies, like genetic sequencing, have played a pivotal role in enhancing our comprehension of congenital vascular and lymphatic disorders. Nonetheless, the uncommon and complex characteristics of these disorders, especially considering their formation during the intrauterine stage, present significant obstacles in diagnosis and treatment. Here, we review the intricacies of these congenital abnormalities, offering an in-depth examination of key diagnostic approaches, genetic factors, and therapeutic methods.

Giant vascular malformations invading the skull: A case report

BACKGROUND

Vascular malformations (VMs) arise as a result of errors in the process of angiogenesis and are usually present at birth, but may not become apparent until after birth. However, giant VMs of the head and face are uncommon, with few reported cases, and the prognosis for their surgical intervention is unclear.

CASE SUMMARY

A 12-year-old girl was admitted to the hospital with findings of an enlarged right temporal scalp. After admission, computed tomography (CT) angiography of cerebral ateries showed a right occlusal gap and a right temporal artery venous malformation. Furthermore, cerebral angiography showed a right temporal lobe VM with multiple vessels supplying blood. The patient underwent surgery to remove the malformed vessels and the eroded skull. Two hours after the surgery, the patient's right pupil was dilated, and an urgent CT scan of the skull showed a right subdural haematoma under the incision, which was urgently removed by a second operation. After surgery, we gave continuous antibiotic anti-infection treatment, and the patient recovered well and was discharged two weeks later.

CONCLUSION

Surgical removal of giant haemangiomas is risky and adequate preoperative (including interventional embolisation) and intraoperative preparations should be made.

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.

Our Experience in the Surgical Management of Arterio-Venous Malformations of the head and neck

Introduction

Vascular anomalies comprise a diverse group of abnormalities in blood vessel morphogenesis that usually occur prenatally. Arterio-venous malformations (AVMs) are rare congenital vascular lesions accounting for 1.5% of all vascular anomalies, with 50% of them occur in the oral and maxillo-facial regions. Treatment of large, complex vascular lesions is a serious challenge for patients and surgeons because it can cause disfigurement and massive haemorrhage, which may be spontaneous or the result of surgical intervention. Our study aimed to demonstrate surgical management of massive AVMs of the head and neck.

Method

This retrospective study shows the treatment outcomes of 28 patients with massive maxillo-facial vascular malformations, who presented to our department for treatment from 1 January 2015 to 31 July 2022.

Results

Twenty-eight patients with a mean age of 17.32 ± 12.21 years (women: 15, men: 13) were enrolled in the study. Diagnosis included extra cranial AVMs of the head and neck region. Treatment modalities, in isolation or combination, included angioembolisation procedure, sclerotherapy, and surgery.

Conclusion

Management of AVMs is challenging owing to the replacement of normal tissue by the diseased ones and the high rate of recurrence. Hence, multi-modal approaches are needed for the effective restoration of tissues.

Soft Tissue Vascular Anomalies of the Extremities: A Proposed Diagnostic Approach

This narrative review aims to summarise the classification of vascular anomalies, their clinical presentation, and their radiological features to propose a diagnostic algorithm to approach patients with suspected soft tissue vascular anomalies of the extremities. The management of vascular anomalies necessitates a multidisciplinary approach. Clinical presentation and physical examination are sufficient in most cases to achieve a correct diagnosis. This is especially true for small congenital lesions of the skin and subcutaneous tissue. Imaging is used for accurate characterization of these lesions, especially in cases of atypical or vague clinical presentation, and to assess extension in cases of lesions that are larger and localized in deeper tissues.

Interdisciplinary Management of Vascular Anomalies in the Head and Neck

Vascular anomalies in the head and neck area are usually rare diseases and pose a particular diagnostic and therapeutic challenge. They are divided into vascular tumours and vascular malformations. A distinction is made between benign tumours, such as infantile haemangioma, and rare malignant tumours, such as angiosarcoma. Vascular malformations are categorised as simple malformations, mixed malformations, large vessel anomalies and those associated with other anomalies. Treatment is interdisciplinary and various modalities are available. These include clinical observation, sclerotherapy, embolisation, ablative and coagulating procedures, surgical resection and systemic drug therapy. Treatment is challenging, as vascular anomalies in the head and neck region practically always affect function and aesthetics. A better understanding of the genetic and molecular biological basis of vascular anomalies has recently led to clinical research into targeted drug therapies. This article provides an up-to-date overview of the diagnosis, clinic and treatment of vascular anomalies in the head and neck region.

Tumescent solution: a game changer in excising refractory arteriovenous malformation

Arteriovenous malformations of the head and neck are rare and inborn errors of vascular morphogenesis. They pose therapeutic challenges owing to their bleeding tendency and a high chance of recurrence. Treatment modalities include digital subtraction angiography with embolisation as a primary treatment or can be done preoperatively followed by surgical excision. We present a case of recurrent arteriovenous malformation of the postauricular region in an adolescent male who was taken up for upfront surgical excision with the help of a tumescent solution, thereby eliminating the need for embolisation and drastically reduced intraoperative blood loss.

Management of Midfacial and Skull Vault Osseous Vascular Lesions

There continuous to be widespread misuse of nomenclature used to described vascular anomalies, This is even more pronounced in the case of intra-osseous lesions. Bone involvement is more common with vascular malformations and extremely rare in haemangiomas. An accurate diagnosis is mandatory for tailored management and often based on a thorough history, clinical examination, and cross-sectional imaging. Surgery remains the main stay for the management of symptomatic venous malformations. Embolisation with or without surgery is the main stay for arteriovenous malformations. Virtual surgical planning, with surgical guides and patient specific implants help achieve predictably excellent results.

Targeting the microenvironment in the treatment of arteriovenous malformations

Extracranial arteriovenous malformations (AVMs) are regarded as rare diseases and are prone to complications such as pain, bleeding, relentless growth, and high volume of shunted blood. Due to the high vascular pressure endothelial cells of AVMs are exposed to mechanical stress. To control symptoms and lesion growth pharmacological treatment strategies are urgently needed in addition to surgery and interventional radiology. AVM cells were isolated from three patients and exposed to cyclic mechanical stretching for 24 h. Thalidomide and bevacizumab, both VEGF inhibitors, were tested for their ability to prevent the formation of circular networks and proliferation of CD31+ endothelial AVM cells. Furthermore, the effect of thalidomide and bevacizumab on stretched endothelial AVM cells was evaluated. In response to mechanical stress, VEGF gene and protein expression increased in patient AVM endothelial cells. Thalidomide and bevacizumab reduced endothelial AVM cell proliferation. Bevacizumab inhibited circular network formation of endothelial AVM cells and lowered VEGF gene and protein expression, even though the cells were exposed to mechanical stress. With promising in vitro results, bevacizumab was used to treat three patients with unresectable AVMs or to prevent regrowth after incomplete resection. Bevacizumab controlled bleeding, pulsation, and pain over the follow up of eight months with no patient-reported side effects. Overall, mechanical stress increases VEGF expression in the microenvironment of AVM cells. The monoclonal VEGF antibody bevacizumab alleviates this effect, prevents circular network formation and proliferation of AVM endothelial cells in vitro. The clinical application of bevacizumab in AVM treatment demonstrates effective symptom control with no side effects.

Wide Resection for Pediatric Extremity Vascular Malformation-A Tertiary Hospital's Experience

BACKGROUND

Vascular malformations of the extremities (VM) are common benign lesions that tend to grow throughout the patient's lifetime. They can cause various issues like pain, swelling, and even limb length discrepancies. Sclerotherapy was the preferred treatment choice in previous studies. However, sclerotherapy and many other treatments have the potential to result in higher recurrence rates. Surgical treatment has been shown to be effective and safe in many cases. Hence, this study aims to evaluate the suitability of wide resection surgery for VM to reduce recurrence.

METHODS

Fort-seven VM cases that underwent wide resection were identified retrospectively in the institution of study. Demographics, depth of malformation, whether malformations were local or diffuse, location and size of malformations, and histology records were taken note of. Records of recurrence and postoperative function were also gathered. We utilized self-reported questionnaires, QuickDASH and Lower Extremity Functional Scale, to determine patients' postsurgical physical function.

RESULTS

Out of 47 cases that underwent wide resection, we found a recurrence rate of 2.1%. No patients sustained any loss of function postsurgery, with few patients experiencing minor complications like tenderness, hypertrophic scars/keloids, as well as numbness. Good functionality posttreatment was also seen through self-reported questionnaires, with an average score of 2.12 for QuickDASH and 99.96% for LEFS.

CONCLUSION

Where margins can be obtained without functional impairment, surgical-wide resection for VM is a viable treatment option to minimize recurrence.

LEVEL OF EVIDENCE

Level-IV.

68 Ga-FAPI-04 Detected Hepatic Arteriovenous Malformation in a Patient With IgA Nephropathy

ABSTRACT

A 51-year-old woman with a history of IgA nephropathy was found to have a mass in the right lobe of the liver by abdominal ultrasound. The PET/CT scan revealed elevated 68 Ga-FAPI-04 uptake in the aforementioned lesion, indicating the potential presence of liver cancer. However, subsequent histopathological analysis confirmed it to be an arteriovenous malformation. This case illustrates that 68 Ga-FAPI-04 uptake can occur in arteriovenous malformation and is a benign cause of 68 Ga-FAPI-04 uptake.

A Microsurgical Arteriovenous Malformation Model on Saphenous Vessels in the Rat

Arteriovenous malformation (AVM) is an anomaly of blood vessel formation. Numerous models have been established to understand the nature of AVM. These models have limitations in terms of the diameter of the vessels used and the impact on the circulatory system. Our goal was to establish an AVM model that does not cause prompt and significant hemodynamic and cardiac alterations but is feasible for follow-up of the AVM's progression. Sixteen female rats were randomly divided into sham-operated and AVM groups. In the AVM group, the saphenous vein and artery were interconnected using microsurgical techniques. The animals were followed up for 12 weeks. Anastomosis patency and the structural and hemodynamic changes of the heart were monitored. The hearts and vessels were histologically analyzed. During the follow-up period, shunts remained unobstructed. Systolic, diastolic, mean arterial pressure, and heart rate values slightly and non-significantly decreased in the AVM group. Echocardiogram results indicated minor systolic function impact, with slight and insignificant changes in aortic pressure and blood velocity, and minimal left ventricular wall enlargement. The small-caliber saphenous AVM model does not cause acute hemodynamic changes. Moderate but progressive alterations and venous dilatation confirmed AVM-like features. The model seems to be suitable for studying further the progression, enlargement, or destabilization of AVM.

Relative expression of hormone receptors by endothelial and smooth muscle cells in proliferative and non-proliferative areas of congenital arteriovenous malformations

BACKGROUND

Episodic growth due to microvascular proliferations (MVP) has been reported in congenital arteriovenous malformations (AVM), which are normally quiescent lesions composed of mature malformed vessels. Since AVM also may worsen under conditions of hormonal dysregulation, we hypothesized that hormonal influences may stimulate this process of vasoproliferative growth through potential interactions with hormone receptors (HR).

METHODS

13 Cases of AVM tissue with histologically documented vasoproliferative growth were analyzed quantitatively for the presence and tissue localization of estrogen receptor (ER), progesterone receptor (PGR), growth hormone receptor (GHR) and follicle-stimulating hormone receptor (FSHR) in relation to resident cells of interest (endothelial cells (EC), smooth muscle cells (SMC) and mast cells (MC)) by applying multiplex immunohistochemistry (IHC) staining. Expression patterns in lesions with MVP and mature vessels were quantified and compared. Available fresh frozen tissues of 3 AVM samples were used to confirm the presence of HR using Reverse-Transcriptase quantitative Polymerase Chain Reaction (RT-qPCR).

RESULTS

All four HR studied were expressed in all cases within EC and SMC in areas of MVP and mature vessels, but not in normal skin tissue. ER, GHR, and FSHR showed more expression in EC of MVP and in SMC of mature vessels. RT-qPCR confirmed presence of all 4 HR in both areas.

CONCLUSION

Expression of ER, PGR, GHR, and FSHR in vasoproliferative areas of congenital AVM could explain onset of sudden symptomatic growth, as has observed in a subpopulation of patients. These findings may have implications for eventual anti-hormonal targeted therapy in the lesions involved.

Untargeted plasma metabolome identifies biomarkers in patients with extracranial arteriovenous malformations

Objective: This study aimed to investigate the plasma metabolic profile of patients with extracranial arteriovenous malformations (AVM). Method: Plasma samples were collected from 32 AVM patients and 30 healthy controls (HC). Ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) was employed to analyze the metabolic profiles of both groups. Metabolic pathway enrichment analysis was performed through Kyoto Encyclopedia of Genes and Genomes (KEGG) database and MetaboAnalyst. Additionally, machine learning algorithms such as Least Absolute Shrinkage and Selection Operator (LASSO) and random forest (RF) were conducted to screen characteristic metabolites. The effectiveness of the serum biomarkers for AVM was evaluated using a receiver-operating characteristics (ROC) curve. Result: In total, 184 differential metabolites were screened in this study, with 110 metabolites in positive ion mode and 74 metabolites in negative mode. Lipids and lipid-like molecules were the predominant metabolites detected in both positive and negative ion modes. Several significant metabolic pathways were enriched in AVMs, including lipid metabolism, amino acid metabolism, carbohydrate metabolism, and protein translation. Through machine learning algorithms, nine metabolites were identify as characteristic metabolites, including hydroxy-proline, L-2-Amino-4-methylenepentanedioic acid, piperettine, 20-hydroxy-PGF2a, 2,2,4,4-tetramethyl-6-(1-oxobutyl)-1,3,5-cyclohexanetrione, DL-tryptophan, 9-oxoODE, alpha-Linolenic acid, and dihydrojasmonic acid. Conclusion: Patients with extracranial AVMs exhibited significantly altered metabolic patterns compared to healthy controls, which could be identified using plasma metabolomics. These findings suggest that metabolomic profiling can aid in the understanding of AVM pathophysiology and potentially inform clinical diagnosis and treatment.

Clinical phenotype of adolescent and adult patients with extracranial vascular malformation

OBJECTIVE

In recent years, genotypic characterization of congenital vascular malformations (CVMs) has gained attention; however, the spectrum of clinical phenotype remains difficult to attribute to a genetic cause and is rarely described in the adult population. The aim of this study is to describe a consecutive series of adolescent and adult patients in a tertiary center, where a multimodal phenotypic approach was used for diagnosis.

METHODS

We analyzed clinical findings, imaging, and laboratory results at initial presentation, and set a diagnosis according to the International Society for the Study of Vascular Anomalies (ISSVA) classification for all consecutively registered patients older than 14 years of age who were referred to the Center for Vascular Malformations at the University Hospital of Bern between 2008 and 2021.

RESULTS

A total of 457 patients were included for analysis (mean age, 35 years; females, 56%). Simple CVMs were the most common (n = 361; 79%), followed by CVMs associated with other anomalies (n = 70; 15%), and combined CVMs (n = 26; 6%). Venous malformations (n = 238) were the most common CVMs overall (52%), and the most common simple CVMs (66%). Pain was the most frequently reported symptom in all patients (simple, combined, and vascular malformation with other anomalies). Pain intensity was more pronounced in simple venous and arteriovenous malformations. Clinical problems were related to the type of CVM diagnosed, with bleeding and skin ulceration in arteriovenous malformations, localized intravascular coagulopathy in venous malformations, and infectious complications in lymphatic malformations. Limb length difference occurred more often in patients with CVMs associated with other anomalies as compared with simple or combined CVM (22.9 vs 2.3%; P < .001). Soft tissue overgrowth was seen in one-quarter of all patients independent of the ISSVA group.

CONCLUSIONS

In our adult and adolescent population with peripheral vascular malformations, simple venous malformations predominated, with pain as the most common clinical symptom. In one-quarter of cases, patients with vascular malformations presented with associated anomalies on tissue growth. The differentiation of clinical presentation with or without accompanying growth abnormalities need to be added to the ISSVA classification. Phenotypic characterization considering vascular and non-vascular features remains the cornerstone of diagnosis in adult as well as pediatric patients.

Management of scalp arteriovenous malformations: a rising trend towards percutaneous direct puncture embolization technique-our experience

BACKGROUND

Scalp arteriovenous malformations (AVMs), or cirsoid aneurysms of the scalp, usually present with troublesome symptoms and cosmetic disfigurement. Endovascular/percutaneous embolization has evolved as a sole treatment method or adjunct to surgical excision in the management of scalp AVMs with an excellent outcome.

PURPOSE

To discuss minimally invasive techniques for treating scalp AVMs as well as to highlight the role of embolization before surgery.

MATERIAL AND METHODS

This is a retrospective study of 50 patients with scalp AVM who underwent embolization (percutaneous/endovascular) during 2010-2019 at a tertiary care center. n-butyl cyanoacrylate (n-BCA) was used as an embolizing agent in all the cases and the patients were followed up at three- and six-month intervals with Doppler evaluation.

RESULTS

A total of 50 patients were included in the study. The occipital region was the most common location; 82% were Schobinger class II lesions and 18% were class III lesions. Thirteen patients had small-sized AVMs and 37 patients had large-sized AVMs. Post-embolization surgery was performed in 36 patients. Of the patients, 28 underwent percutaneous embolization, 20 underwent endovascular embolization, and two underwent both to achieve complete embolization of the lesion. The number of percutaneous procedures increased in the latter half of the study period as the safety and efficacy of the technique were established. No major complications were seen in this study.

CONCLUSION

Embolization of scalp AVMs is a safe and effective technique and can be used in isolation for small lesions and as an adjunct procedure to surgery for large-sized lesions.

A 16-year retrospective study of vascular anomalies in the head and neck region

Depending on the diagnostic modality, the classification of vascular anomalies varies and so does the nomenclature. The 'International Society for the Study of Vascular Anomalies' (ISSVA) is the most widely accepted classification in the literature and is mainly based on the radiologic and clinical presentation. The aim of this article is to review the clinical practice of diagnosis and treatment of vascular anomalies in the head and neck region in a university hospital, with special focus on the nomenclature. All patients with a vascular anomaly presenting to the department of oral and maxillofacial surgery were reviewed in a retrospective manner. Nomenclature, diagnostic process, lesion characteristics, treatment and outcome were examined. The lesions were (re)classified according to the ISSVA classification. A total of 185 patients were identified, of which 12.4% (n = 23) had a congenital anomaly. After reclassification, the most common lesions were venous malformations (n = 47, 25.4%), followed by lobular capillary hemangiomas (n = 17, 9.2%). A group of 39 anomalies could not be further specified. One hundred and one patients (54,6%) received treatment, of which 93 were treated surgically (92,1% of treated patients). Endovascular treatment was considered in 41 patients but applied in only eight. This strict selection led to a low a complication rate. We provide an overview of the clinical practice in the management of vascular anomalies in a university hospital. The histology report is a source of miscommunication because clinicians use the ISSVA classification, while pathologists use the WHO classification. Every professional involved should be aware of the differences in classification and nomenclature.

Arteriovenous malformation Map2k1 mutation affects vasculogenesis

Somatic activating MAP2K1 mutations in endothelial cells (ECs) cause extracranial arteriovenous malformation (AVM). We previously reported the generation of a mouse line allowing inducible expression of constitutively active MAP2K1 (p.K57N) from the Rosa locus (R26GT-Map2k1-GFP/+) and showed, using Tg-Cdh5CreER, that EC expression of mutant MAP2K1 is sufficient for the development of vascular malformations in the brain, ear, and intestines. To gain further insight into the mechanism by which mutant MAP2K1 drives AVM development, we induced MAP2K1 (p.K57N) expression in ECs of postnatal-day-1 pups (P1) and investigated the changes in gene expression in P9 brain ECs by RNA-seq. We found that over-expression of MAP2K1 altered the transcript abundance of > 1600 genes. Several genes had > 20-fold changes between MAP2K1 expressing and wild-type ECs; the highest were Col15a1 (39-fold) and Itgb3 (24-fold). Increased expression of COL15A1 in R26GT-Map2k1-GFP/+; Tg-Cdh5CreER+/- brain ECs was validated by immunostaining. Ontology showed that differentially expressed genes were involved in processes important for vasculogenesis (e.g., cell migration, adhesion, extracellular matrix organization, tube formation, angiogenesis). Understanding how these genes and pathways contribute to AVM formation will help identify targets for therapeutic intervention.

Intramuscular capillary-type hemangioma: Diagnosis, treatment, and outcomes. A French multicentric retrospective study of 66 cases

PURPOSE

Intramuscular capillary-type hemangiomas (ICTHs) are rare entities, belonging to the group of intramuscular "hemangiomas." The diagnosis remains challenging. We aimed to assess the diagnostic criteria, treatments and outcomes of ICTHs.

METHODS

This retrospective study collected all cases of ICTH followed up in 9 French hospital centers, reviewed by an adjudication expert group.

RESULTS

Among 133 patients screened, 66 with ICTH were included. The median age of patients at diagnosis was 28.0 years, interquartile range (21.0---36.0). The lesion, mainly presenting as a gradually increasing mass (83.9%), was painless (88.9%) and was located in the head and neck (42.4%). MRI (available in all cases) mainly revealed a well-delineated lesion, isointense to the muscle on T1-weighted images, with enhancement after contrast injection; hyperintense on T2-weighted images; and containing flow voids. Among the 66 cases, 59 exhibited typical ICTH features and 7 shared some imaging features with arteriovenous malformations. These latter were larger than typical ICTHs and more painful and appeared on imaging as less well delimited and more heterogeneous tissue masses, with larger tortuous afferent arteries, earlier draining vein opacification and mild arteriovenous shunting. We propose to name these lesions arteriovenous malformation (AVM)-like ICTH. Pathological reports were similar in typical and AVM-like ICTH, showing capillary proliferation with mainly small-size vessels, negative for GLUT-1 and positive for ERG, AML, CD31 and CD34, with low Ki67 proliferation index (<10%), and adipose tissue. The most frequent treatment for ICTH was complete surgical resection (17/47, 36.2%), preceded in some cases by embolization, which led to complete remission.

CONCLUSIONS

ICTH can be diagnosed on MRI when it is typical. Biopsy or angiography are required for atypical forms.

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.

Head and Neck Arteriovenous Malformations: Clinical Manifestations and Endovascular Treatments

Arteriovenous malformations (AVMs) are vascular malformations that present high-flow direct communication between the arteries and veins, not involving the capillary beds. They can be progressive and lead to various manifestations, including abnormal skin or mucosal findings, ischemia, hemorrhage, and high-output heart failure in severe cases. AVMs often involve the head and neck region. Head and neck AVMs can present region-specific clinical manifestations, angioarchitecture, and complications, especially in cosmetic appearance and ingestion, respiratory, and neuronal functions. Therefore, when planning endovascular treatment of head and neck AVMs, physicians should consider not only the treatment strategy but also the preservation of the cosmetic appearance and critical functions. Knowledge of the functional vascular anatomy as well as treatment techniques should facilitate a successful management. This review summarizes AVMs' clinical manifestations, imaging findings, treatment strategy, and complications.

Endovascular and Percutaneous Embolotherapy for the Body and Extremity Arteriovenous Malformations

Arteriovenous malformations (AVMs) consist of abnormal communications between the arteries and veins. They can involve any part of the body and extremity and grow in proportion to age and in response to hormonal influence or trauma. When symptoms progress from Schöbinger clinical stage II to III, transcatheter and/or direct puncture embolization are less-invasive and repeatable options for symptom palliation. The goal of embolization is to obliterate the AV shunt, and the choice of lesion access and embolic agents is based on the individual anatomy and flow. Embolization can be technically challenging due to complex vascular anatomy and morbidity risks. Therefore, a multidisciplinary management is essential for the diagnosis and therapeutic intervention of AVMs.

Treatment of Challenging Extracranial Arteriovenous Malformations: A Single-Center Experience and Literature Review

ABSTRACT

Extracranial arteriovenous malformation (AVM) is a high-flow congenital vascular malformation, where direct communication between the arteries and veins impedes perfusion of capillary beds and causes disfigurement of the affected tissue. Surgery and endovascular therapy are currently the main treatment for extracranial AVMs. Nevertheless, management of complex cases is sometimes challenging because of severe complications such as refractory ulceration, life-threatening bleeding, and even cardiac insufficiency. Here, we reviewed the development and potential treatment for extracranial AVMs and shared our single-center experiences of diagnosis and treatment of this challenging disease.

A Rare Case of Scalp Arteriovenous Malformation in an Adolescent Patient

Scalp arteriovenous malformations (AVMs) are rare lesions that arise due to a pathological fistulous connection between scalp arterial feeders and draining veins without the involvement of capillary beds. Here, we report a case of a 17-year-old male who presented with an enlarging, pulsatile, mass in the scalp of the parietal region with mild headaches and was diagnosed with a scalp AVM that was treated successfully with endovascular trans-arterial embolization. Scalp AVMs are uncommon extracranial vascular abnormalities that neurosurgeons hardly ever see. To precisely define the angiographic architecture of an AVM and to organize further management, digital subtraction angiography is crucial.

Characteristics, Natural Course and Treatment of Intramuscular Capillary-type Haemangioma: A Systematic Literature Review

Intramuscular capillary-type haemangiomas (ICTH) are rare vascular anomalies that can easily be misdiagnosed as other entities. A systematic review was performed of all cases of ICTH in the literature since its first description in 1972. An adjudication committee reviewed cases to include only ICTHs. Among 1,143 reports screened, 43 were included, involving 75 patients. The most frequent differential diagnosis was intramuscular venous malformations. The mean age of patients at diagnosis was 21.2 years. ICTH was mainly described as a gradually increasing mass (81.8%), painless (73.9%), that could occur anywhere in the body but most frequently on the head and neck (44.0%). Magnetic resonance imaging (MRI) was mainly used for diagnosis (69.1%) and displayed specific features. The most frequent treatment was complete surgical removal (73.9%), which could be preceded by embolization, and led to complete remission without recurrence in all but 1 case.

Long-term changes of health-related quality of life in patients with peripheral vascular malformations - a prospective observational study

PURPOSE

The aim of this observational study was to assess health-related quality of life (HRQOL) changes in patients with vascular malformations, over a period of almost eight years, and to assess clinical and demographic characteristics possibly associated with HRQOL changes.

METHODS

Eighty out of 111 patients who were included in a previously published comparative HRQOL study accepted inclusion in this follow-up study. HRQOL at baseline and follow-up was assessed with the Short-Form 36-item questionnaire (SF-36). Median observation time was 7.9 years. Linear mixed models and linear regression models were applied to assess HRQOL change and possible associations with demographic and clinical variables.

RESULTS

The median age of the patient cohort at baseline evaluation (n = 111) was 27.0 years. Ninety-six out of 111 (86.5%) patients were diagnosed with venous malformations. Significantly higher SF-36 scores at follow-up were found for the physical domains Role limitations due to (RLDT) physical problems (difference=13.5; 95% CI [1.6, 25.3]) and Bodily pain (difference=11.3; 95% CI [3.8, 18.8]). No deterioration of HRQOL was found in any domain. In multivariate analyses, female gender, muscle/bone involvement, and higher age were associated with a positive relative change in SF-36 in the domains Physical functioning, RLDT physical problems, and RLDT emotional problems, respectively. Invasive treatment was not associated with long-term HRQOL change.

CONCLUSIONS

Over a period of almost eight years, significant improvement of SF-36 scores was observed in the physical domains RLDT physical problems and bodily pain. Female gender, muscle/bone involvement, and higher age were associated with HRQOL improvement in certain domains.

Extensive severe intraorbital arteriovenous malformations: report of a rare laser complication and successful management

Arteriovenous malformations (AVMs) are rare congenital errors of vascular morphogenesis, characterised by abnormal direct communications between arteries and veins, bypassing the normal capillary bed. Apart from the central nervous system, typical locations include the head and neck, and less frequently limbs, trunk or internal organs. AVMs of the head and neck often become clinically evident and symptomatic only in later childhood and are characterised by a history of variable growth, sometimes leading to large, deforming, pulsating masses with a propensity to massive haemorrhage. Therapeutic strategy is based on selective embolisation, surgical excision, or a combination of both. Radical surgical excision of local AVMs is the only effective treatment but it may be mutilating, especially for AVMs of the head and neck. Laser therapy represents a good option to treat the cutaneous aspects of AVMs nevertheless, its efficacy is limited. To the date, pharmacological therapy for AVMs is still on debate due to its controversial outcomes as it seems not as effective as other treatments and usually requires a longer course of application. However, pharmacological therapy could be useful in selected patients and for AVMs nonresponsive to traditional treatment, allowing them to obtain acceptable results without serious complications. This paper reports the case of a serious laser complication of extensive intraorbital AVM successfully treated by local reconstruction and topical pharmacological treatment.

Clinical Outcome and Quality of Life of Multimodal Treatment of Extracranial Arteriovenous Malformations: The APOLLON Study Protocol

PURPOSE

Arteriovenous malformations (AVMs) as rare diseases are diagnostically and therapeutically challenging. Due to the limited evidence regarding treatment outcome, prospective data are needed on how different treatment regimens affect outcome. The aims of this prospective trial are to determine effectiveness, safety, and clinical outcome of multimodal treatment in patients with extracranial AVMs.

MATERIALS AND METHODS

After clinical and magnetic resonance imaging (MRI)-based diagnosis and informed consent, 146 patients (> 4 years and < 70 years) undergoing multimodal therapy in tertiary care vascular anomalies centers will be included in this prospective observational trial. Treatment options include conservative management, medical therapy, minimally invasive image-guided procedures (embolization, sclerotherapy) and surgery as well as combinations of the latter. The primary outcome is the patient-reported QoL 6 months after completion of treatment using the short form-36 health survey version 2 (SF-36v2) and the corresponding short form-10 health survey (SF-10) for children. In addition, clinical presentation (physician-reported signs), MRI imaging (radiological assessment of devascularization), recurrence rate, and therapeutic safety will be analyzed. Further follow-up will be performed after 12, 24, and 36 months. Moreover, liquid biopsies are being obtained from peripheral blood at multiple time points to investigate potential biomarkers for therapy response and disease progression.

DISCUSSION

The APOLLON trial is a prospective, multicenter, observational open-label trial with unequal study groups to generate prospective evidence for multimodal treatment of AVMs. A multicenter design with the potential to assess larger populations will provide an increased understanding of multimodal therapy outcome in this orphan disease.

TRIAL REGISTRATION

German Clinical Trials Register (identification number: DRKS00021019) https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021019 .

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.

Super-selective and staged glue embolization for labral AVMs using ultra-thin microcatheters: report of two cases

BACKGROUND

Treating arteriovenous malformation (AVM) is challenging because of the high recurrence rate and because incomplete resection or embolization can induce aggressive growth. However, a standard strategy is not fully established. Although transcatheter arterial embolization (TAE) is currently almost always part of the treatment, in many cases, single treatment is not curative and only palliative. Additionally, the success and complication rates associated with TAE alone are unclear, and there has been limited study of staged TAE for facial AVMs. Furthermore, few reports have described the details of the procedure.

CASE-PRESENTATION

We report two cases of AVM of the upper lip in patients who were successfully treated by staged super-selective TAE at several-month intervals using ultra-thin microcatheters and n-butyl-2-cyanoacrylate.

CONCLUSION

Staged and super-selective TAE may prevent complications and provide high curability and might be a useful treatment in cases of AVM.

Extracranial arteriovenous malformations demonstrate dysregulated TGF-β/BMP signaling and increased circulating TGF-β1

Extracranial arteriovenous malformations (AVMs) are characterized by anomalous arterial-to-venous connections, aberrant angiogenesis, local inflammation and hypoxia, and disorganized histological architecture; however, the precise molecular perturbations leading to this phenotype remain elusive. We hypothesized that extracranial AVM tissue would demonstrate deregulation of the TGF-β/BMP signaling pathway, which may serve as a potential target in the development of molecular-based therapies for AVMs. AVM tissue was harvested during resection from 10 patients with AVMs and compared to control tissue. Blood was collected from 14 AVM patients and 10 patients without AVMs as controls. Expression of TGF-β/BMP pathway components was analyzed using RT-PCR, western blotting, and immunohistochemistry. Circulating levels of TGF-β1 were analyzed by ELISA. Paired t tests were utilized to perform statistical analysis. The mRNA levels of TGF-β1, ALK1, Endoglin (ENG), Smad6, Smad7, and Smad8 were significantly elevated in AVM tissue when compared to controls. Protein levels of TGF-β1 and Smad3 were elevated in AVM tissue while protein levels of BMP-9, ALK1, Smad1, Smad6, and Smad8 were significantly decreased in AVMs. Immunohistochemistry demonstrated increased TGF-β1 in the perivascular cells of AVMs compared to normal controls, and circulating levels of TGF-β1 were significantly higher in AVM patients. Patients with AVMs demonstrate aberrant TGF-β/BMP expression in AVM tissue and blood compared to controls. Targeting aberrantly expressed components of the TGF-β/BMP pathway in extracranial AVMs may be a viable approach in the development of novel molecular therapies, and monitoring circulating TGF-β1 levels may be a useful indicator of treatment success.

Exclusive surgical approach for facial arteriovenous malformations in precarious conditions

Arteriovenous malformations (AVMs) are high-flow vascular lesions that does not regress spontaneously. They are located in the cranio-facial region in 50% of cases. Most of the time, the management of these lesions is a combination of surgery and vascular embolization. However, when the conditions are precarious, even without access to embolization, it's possible to treat some of those lesions with safety. We report four cases of patients suffering from cranio-facial AVM, treated exclusively by surgery during humanitarian missions.

Interventional embolization combined with surgical resection for treatment of extracranial AVM of the head and neck: A monocentric retrospective analysis

Objectives

The aim of this study was to demonstrate the efficacy and feasibility of treating patients with extracranial arteriovenous malformations (AVM) of the head and neck with interventional embolization followed by surgical resection.

Methods

We reviewed the charts of all patients between 2012 and 2021 with extracranial AVM of the head and neck scheduled for interdisciplinary treatment according to University Hospital RWTH Aachen’s protocol and conducted standardized interviews using a newly developed questionnaire. Interview results, as well as clinical examination and radiographic outcome results were analyzed to help determine the efficacy of our treatment approach.

Results

We included 10 patients (8 female, 2 male), with a mean age of 33.5 (11–61) years who were scheduled for treatment of the AVM with interventional embolization followed by surgical resection. In 6 of the 10 patients (60%) the lesion was located in extracranial soft tissue only. In one patient (10%), the lesion was located in bone tissue only. A combined intraosseous and oral soft tissue lesion was seen in the remaining 3 patients (30%). Radiographic resolution was achieved in 62.5% of cases and a significant decrease of symptoms was identified (p = 0.002). None of the patients reported dissatisfaction and no major complications occurred.

Conclusion

An interdisciplinary treatment approach combining neuroradiological interventions with surgical resection appears to be an effective treatment with an acceptable complication rate. Patients treated according to our protocol showed a high satisfaction rate, regardless of the radiographic outcome. Standardized follow-up allows for early detection of recurrences and helps with subjective patient satisfaction.

Interventional therapy of extracranial arteriovenous malformations of the head and neck—A systematic review

Objectives

The primary aim of this study was to conduct a meta-analysis of the literature on interventional treatment for patients with extracranial AVM of the head and neck to identify a superior treatment. The secondary aim was to evaluate the methodological quality of associated articles published between 2000–2020.

Methods

The literature search was conducted on PubMed, Embase, the Cochrane Library, and scholar.google.com. Studies, meeting the acceptable reference standard underwent meta-analysis. All identified literature underwent methodological quality analysis.

Results

Of 1560 screened articles, 56 were included in the literature review. Appropriate diagnostic tests were reported in 98% of included articles. 13% of included articles did not specify the embolization agent. Outcome analysis varied throughout. 45% of the authors used radiographic imaging for follow-up. 77% specified the span of follow-up of their entire patient collective. Two articles met the inclusion criteria for meta-analysis. Curing rate of transarterial ethanol embolization for intraosseous AVM was 83% with a complication rate of 58%. Curing rate of ethanol combined with NBCA or Onyx in soft tissue AVM was 18% with a complication rate of 87%.

Conclusion

Our literature review revealed an absence of treatment or reporting standards for extracranial AVM of the head and neck. The meta-analysis is comprised of two articles and methodological quality is heterogeneous. We recommend implementing consistent reporting standards to facilitate comparability of studies and to provide robust data for the development of an evidence-based treatment strategy.

Advances in knowledge

Meta-analysis showed a favorable radiological outcome for intraosseous AVM when treated with intraarterial ethanol embolization. Our analysis demonstrated that the published data on extracranial AVMs of the head and neck is lacking in consistency and quality, prompting agreement for the need of standardized reporting on AVM treatments.

Head and neck arteriovenous malformations: University of Tennessee experience, 2012–2022

OBJECTIVE

Head and neck arteriovenous malformations (AVMs) are complex lesions that represent a subset of vascular anomalies (VAs). The authors present an analysis of their institutional experience managing these lesions as a multidisciplinary team.

METHODS

A retrospective chart review was performed of head and neck AVM patients treated at the authors’ institution from 2012 to 2022. Recorded data included patient demographic characteristics, details of clinical presentation, Schöbinger clinical scale and Yakes AVM classification results, and details of all endovascular and surgical treatments. The primary outcome of the study was clinical response to treatment. Angiographic occlusion and complication rates were reported. Chi-square tests were used for comparative statistics.

RESULTS

Sixteen patients (9 female, 56%) with AVMs of the head and neck presented from age 3 to 77 years. The Schöbinger stage was stage II in 56% of patients (n = 9) and stage III in 44% of patients (n = 7). The Yakes AVM classification was nidus type (2a, 2b, or 4) in 7 patients (43%) and fistula type (1, 3a, or 3b) in 9 patients (57%). The majority of patients (n = 11, 69.0%) were managed with embolization as the only treatment modality, with an average of 1.5 embolizations/patient (range 1–3). Surgical resection was employed in 5 patients (4 in combination with embolization). Symptom resolution and symptom control were achieved in 69% and 31% of patients, respectively, in the entire cohort. A radiographic cure was demonstrated in 50% of patients. There were no statistical differences in clinical outcomes or radiographic cure rates between patients treated with different modalities.

CONCLUSIONS

Head and neck AVMs can be treated successfully with a primarily endovascular management strategy by a multidisciplinary team with the goal of symptomatic control.

Molecular Pathways and Possible Therapies for Head and Neck Vascular Anomalies

Vascular Anomalies are a heterogenous group of vascular lesions that can be divided, according to the International Society for the Study of Vascular Anomalies Classification, into two main groups : Vascular Tumors and Vascular Malformations. Vascular Malformations can be further subdivided into slow-flow and fast-flow malformations. This clinical and radiological classification allows for a better understanding of vascular anomalies and aims to offer a more precise final diagnosis. Correct diagnosis is essential to propose the best treatment, which traditionally consists of surgery, embolization or sclerotherapy. Since a few years, medical treatment has become an important part of multidisciplinary treatment. Genetic and molecular knowledge of vascular anomalies are increasing rapidly and opens the door for a molecular classification of vascular anomalies according to the underlying pathways involved. The main pathways seem to be: PI3K/AKT/mTOR (PIKopathies) and RAS/RAF/MEK/ERK (RASopathies). Knowing the underlying molecular cascades allows us to use targeted medical therapies. The first part of this article aims to review the vascular anomalies seen in the head and neck region and their underlying molecular causes and involved pathways. The second part will propose an overview of the available targeted therapies based on the affected molecular cascade. This article summarizes theragnostic treatments available in vascular anomalies.

Hemorrhagic shock due to colonic arteriovenous malformation in late pregnancy: a case report

Background

Intestinal arteriovenous malformations are difficult to detect because they often present asymptomatically. However, pregnancy increases the hemorrhagic risk of intestinal arteriovenous malformations. This can lead to massive bleeding and hemodynamic instability, threatening the lives of both the mother and fetus. We describe a life-threatening case of hemorrhagic shock due to a colonic intestinal arteriovenous malformation during late pregnancy that was successfully treated through endovascular management.

Case presentation

A 36-year-old gravida 1, para 1 woman at 35 weeks’ gestation presented with hemodynamic instability and painless hematochezia. The patient had hemorrhagic shock and required massive transfusion. A colonoscopy failed to secure a visual field due to bloody fluid, and endoscopic hemostasis was difficult. Before the bleeding could be controlled, the condition of the fetus continued to deteriorate, showing bradycardia dysrhythmia. Therefore, an emergency cesarean section was performed, which was successful. However, the bleeding did not subside, with the patient’s hemodynamic instability and hematochezia persisting. An angiogram revealed an ascending colonic intestinal arteriovenous malformation, with extravasation of the contrast medium from a branch of the ileocolic artery. Localized blood flow control and hemodynamic stability were achieved via angioembolization. The patient had an uneventful postoperative recovery and was discharged on postoperative day 12. The newborn was admitted to the neonatal intensive care unit. She successfully recovered and was discharged when she was 22 days old.

Conclusions

We reported a case of colonic intestinal arteriovenous malformation resulting in hemodynamic instability due to hematochezia during late pregnancy, which was successfully treated via angioembolization. Intestinal arteriovenous malformation should be considered as a differential diagnosis in pregnant patients with hemodynamic instability and hematochezia.

Atypical case of arteriovenous malformation invading into a pedicled medial arm flap

A 54-year-old woman who had previously undergone total excision of an arteriovenous malformation (AVM) of lower lip and chin along with pedicled medial arm flap reconstruction, presented with recurrence of swelling in the same region. The patient reported progressive difficulty in feeding, talking and constant aching pain besides aesthetic concerns. On evaluation, recurrence of AVM with invasion into the flap substance was identified. We performed debulking surgery, which resulted in a considerable reduction in pain and improved lower lip functioning and aesthetic appeal of the face. This case is unique due to the rare presentation of an AVM invading the normal flap tissue. Such a finding has never been reported before for a pedicled flap, along with details of the histopathology and imaging description. There are lacunae in the understanding of the progression of vascular malformations and this additional information will add to the existing literature on AVM.

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.

Sirolimus used for treatment of retroperitoneal arteriovenous malformation in a premature neonate

We describe a case of a premature infant with antenatally detected retroperitoneal arteriovenous malformation (AVM) with extensive intraspinal extension. Treatment of the malformation with embolectomy and sclerotherapy was not feasible in view of intraspinal extensions and small size of vessels of the lesion. During a trial of propranolol over 20 days, the lesion progressed in size, roughly doubling in volume and was accompanied with deranged coagulation parameters. Treatment was therefore switched to oral prednisolone and sirolimus. The steroid was stopped after 6 weeks and sirolimus was continued with serum drug level monitoring and serial imaging of the malformation. After 4 months of sirolimus, the AVM remained at the same size as at the start of treatment, thus we propose that the drug may have arrested the growth of the lesion. This case highlights the use of sirolimus in management of AVMs in infants.

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.