Ethanol embolization of arteriovenous malformations in the buttock: ten-year experiences in diagnoses and treatment options.

BACKGROUND: Clinically, arteriovenous malformations in the buttocks (bAVMs) are extremely rare. Our study aimed to evaluate the efficacy and safety of ethanol embolotherapy in managing bAVMs. RESULTS: A total of 32 patients with bAVMs (14 females and 18 males) from 2012 to 2021 were included in this study. All patients underwent complete clinical and imaging examinations. Further, the AVMs lesions were analyzed according to Schöbinger staging and Yakes classification. Each patient had undergone a multistage ethanol embolization. The amelioration of clinical symptoms and devascularization on angiography were evaluated at regular follow-ups. In the present cohort, the 11-20 age group had the most patients (15/32; 46.88%). A total of 124 embolization procedures were performed (average 3.88 procedures per patient), and the average dose of absolute ethanol was 18.96 mL per procedure. Thirteen patients with dominant draining veins underwent additional coil deployment before ethanol embolization (13/32; 40.63%). During follow-ups, clinical improvement was found in 23 of 27 who presented with a pulsating mass (85.19%), 17 of 20 with abnormal local skin temperature (85%), 5 of 6 with bleeding (83.33%), and 5 of 5 patients treated for pain (100%). More than 75% angiographic devascularization was achieved in 18 patients (18/32; 56.25%). Finally, 12 out of 13 patients (92.31%) reduced from Schöbinger Stage III to a lower grade, and ten patients exhibited a complete response (10/32; 31.23%). There was a single serious complication of local necrosis, while neither paranesthesia nor infection was observed postoperatively. CONCLUSIONS: Ethanol embolization assisted with coils can treat bAVMs effectively and safely. The Yakes classification contributed to the optimal ethanol embolotherapy of bAVMs.

MicroRNA-135b-5p Is a Pathologic Biomarker in the Endothelial Cells of Arteriovenous Malformations.

Arteriovenous malformations (AVMs) are congenital vascular anomalies with a poor prognosis. AVMs are considered intractable diseases, as there is no established approach for early diagnosis and treatment. Therefore, this study aimed to provide new evidence by analyzing microRNAs (miRNAs) associated with AVM. We present fundamental evidence for the early diagnosis and treatment of AVM by analyzing miRNAs in the endothelial cells of AVMs. This study performed sequencing and validation of miRNAs in endothelial cells from normal and AVM tissues. Five upregulated and two downregulated miRNAs were subsequently analyzed under hypoxia and vascular endothelial growth factor (VEGF) treatment by one-way analysis of variance (ANOVA). Under hypoxic conditions, miR-135b-5p was significantly upregulated in the AVM compared to that under normal conditions, corresponding to increased endothelial activity (p-value = 0.0238). VEGF treatment showed no significant increase in miR-135b-5p under normal conditions, however, a surge in AVM was observed. Under both hypoxia and VEGF treatment, comparison indicated a downregulation of miR-135b-5p in AVM. Therefore, miR-135b-5p was assumed to affect the pathophysiological process of AVM and might play a vital role as a potential biomarker of AVMs for application related to diagnosis and treatment.

[Ischemic stroke due to paradoxical embolism through pulmonary arteriovenous malformation in a young patient]. / ACV isquémico debido a embolia paradojal a través de malformación arteriovenosa pulmonar en paciente joven.

Paradoxical embolism due to an isolated pulmonary arteriovenous malformation (PAVM) is a rare cause of ischemic stroke. PAVMs are abnormal high-flow connections between pulmonary arteries and veins, diverting deoxygenated blood into the systemic circulation and they represent a less common source of paradoxical embolisms, especially in young individuals. Endovascular embolization is the preferred treatment for clinically significant PAVMs. We present the case of a 34-year-old woman with a left thalamic ischemic stroke. Severe contrast passage was detected in cerebral arteries through transcranial Doppler. Intracardiac ultrasound did not reveal a patent foramen ovale, prompting further investigation with pulmonary CT angiography, confirming the presence of PAVM. The patient underwent successful endovascular treatment. It is essential to consider PAVM in the etiological diagnosis of ischemic stroke, especially in young patients with signs of abnormal right-to-left communication. Periodic follow-up imaging is recommended to assess potential recurrence or changes in PAVM, emphasizing the importance of appropriate management of these malformations.

La embolia paradojal debido a una malformación arteriovenosa pulmonar (MAVP) aislada es una causa infrecuente de accidente cerebrovascular (ACV) isquémico. Las MAVP son conductos anómalos de alta circulación entre arterias y venas pulmonares, desviando sangre desoxigenada hacia la circulación sistémica y representan una fuente menos común de embolias paradojales, especialmente en personas jóvenes. La embolización endovascular es el tratamiento preferido para MAVP clínicamente significativas. Presentamos el caso de una mujer de 34 años con ACV isquémico talámico izquierdo. Se detectó pasaje de burbujas "en cortina" en arterias cerebrales mediante Doppler transcraneal. En ecografía intracardíaca no se encontró foramen oval permeable, motivo por el cual se avanzó con realización de angiotomografía pulmonar, la cual confirmó la presencia de MAVP. La paciente recibió tratamiento endovascular exitoso. Es esencial considerar la MAVP en el diagnóstico etiológico del ACV isquémico, especialmente en pacientes jóvenes con signos de comunicación anormal de derecha a izquierda. Se recomienda un seguimiento periódico mediante imágenes para evaluar la posible recurrencia o cambios en la MAVP, resaltando la importancia del manejo adecuado de estas malformaciones.

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.

Personalised stroke evaluation and management: tailoring individualised patient care for hereditary haemorrhagic telangiectasia.

SummaryHereditary haemorrhagic telangiectasia (HHT) has an estimated prevalence of 1 in 5000-8000 individuals globally with pulmonary arteriovenous malformations (PAVMs) affecting approximately 15%-50% of HHT patients. Ischaemic stroke is a known complication of PAVMs that affects ≤30% of patients with PAVMs. Studies have shown that patients with PAVMs have ischaemic stroke a decade earlier than routine stroke. The predominant mechanism of ischaemic stroke in HHT patients is paradoxical embolism due to PAVMs, but most HHT-related PAVMs are asymptomatic. Additionally, HHT is often underdiagnosed in patients and poses a challenge to physicians due to its rarity. We present a case of a patient with ischaemic stroke who was subsequently diagnosed with HHT and found to have a PAVM on further evaluation. This case highlights the importance of using an individualised patient-centred stroke evaluation and screening for PAVMs in patients who had a stroke with possible or suspected HHT and definite HHT.

Microsurgical Treatment for Arteriovenous Malformations in the Hand.

Vascular malformations in the extremities are a common site of occurrence; arteriovenous malformations (AVMs) are the least frequent of all vascular malformations, estimated at 5% to 20%. The first step in management is to perform a thorough clinical examination. Symptoms are assessed, and staging is performed using the Schobinger classification. Next, ultrasonography and contrast-enhanced computed tomography are used to confirm the diagnosis of AVM and to confirm the extent of the malformation. Surgery is the first-line treatment and reconstruction is performed. In cases where surgery is not feasible, embolization and sclerotherapy may be used to alleviate symptoms.

Surgical Treatment of Spontaneous Superficial Temporal Artery Arteriovenous Malformation: A Case Report.

BACKGROUND An arteriovenous malformation (AVM) is an abnormal connection between an artery and a vein, bypassing the capillary network. An AVM of the superficial temporal artery (STA) can occur after trauma, iatrogenic injury, infection, or spontaneously. Spontaneous, or iatrogenic, presentations of STA AVM are thought to be rare, with very few reported cases. Symptoms include local pain, headache, tinnitus, or paresthesia, in addition to a palpable mass associated with thrill on palpation. Options for diagnosis include intra-arterial angiography, doppler ultrasound, magnetic resonance angiography (MRA), and computed tomography angiography (CTA). Current management options include surgical excision, ligation, and embolization; however, it is unknown which treatment is superior in terms of recurrence and which carries a lower risk of complications. CASE REPORT We present a case of a spontaneous STA AVM in a 76-year-old woman with past medical history significant for seasonal allergies and hyperlipidemia, who presented with pulsatile tinnitus and a palpable, tender mass located to the left temporal area. The mass had been present for several years, with gradual increase in size two to three years prior to presentation. She denied any history of trauma or procedure prior to presentation of the pulsatile mass. She underwent open excision with complete resolution of symptoms and no recurrence at 11-month follow-up. CONCLUSIONS AVM of the STA is a condition that can occur secondary to trauma, infection, iatrogenic injury, or spontaneously. Spontaneous, or iatrogenic, presentations of STA AVM are thought to be rare, with very few cases documented in the literature. Surgical treatment remains the standard of management, with options including surgical excision, ligation, or embolization.

Elucidating the pathogenesis behind arteriovenous malformations of the central nervous system: a bibliometric analysis.

Arteriovenous malformations (AVMs) are vascular malformations of the central nervous system (CNS) with potential for significant consequences. The exact pathophysiologic mechanism of AVM formation is not fully understood. This study aims to evaluate bibliometric parameters and citations of the literature of AVMs to provide an overview of how the field has evolved. We performed an electronic search on Web of Science to identify the top 100 published and indexed articles with the highest number of citations discussing the pathogenesis of AVMs. This study yielded 1863 articles, of which the top 100 were selected based on the highest total citation count. These articles included 24% basic science, 46% clinical, and 30% review articles. The most-cited article was a clinical article from 2003, and the most recent was published in 2022. The median number of authors was 6, with the highest being 46 for a clinical article. The top 5 journals were identified, with the highest impact factor being 20.1. 13 countries were identified, with the US contributing the most articles (approximately 70%). Regarding genes of investigation, VEGF was one of the early genes investigated, while more interested in RAS/MAPK has been garnered since 2015. There is a growing interest in AVM genomics and pathogenesis research. While progress has been made in understanding clinical aspects and risk factors, the exact pathophysiological mechanisms and genetic basis of AVM formation remain incompletely understood. Further investigation of key genes in AVM pathogenesis can allow identification of potential therapeutic targets.

Combined Preoperative Endovascular Embolization and Surgical Excision for Scalp Arteriovenous Malformations: A Systematic Review and Case Illustration.

OBJECTIVE: To evaluate the efficacy of the combined approach of preoperative endovascular embolization (EE) and surgical excision (SE) for scalp arteriovenous malformation (AVM) and present an illustrative case report. METHODS: A systematic review was conducted using online databases (PubMed/Medline, Cochrane, and Embase) on February 15, 2023. The inclusion criteria were any type of study of patients with scalp AVMs who were diagnosed and confirmed through angiography and treated with combined preoperative EE and SE. All the articles that met the inclusion criteria were included in this study. RESULTS: A total of 49 articles (91 patients) were included. The patients' age ranged from 10 days to 70 years at the time of presentation. The most common symptoms were a pulsatile mass in 51 patients (56.04%), progressively growing mass in 31 patients (34.06%), and bruits and/or thrills in 22 patients (24.17%). Complications of preoperative EE and SE were observed in only 5 patients; 3 patients (3.29%) had harvested skin graft marginal necrosis, 1 patient (1.09%) had skin necrosis, and 1 patient (1.09%) had a wound infection. Only 2 patients (2.19%) reported a recurrent or residual mass during a median follow-up period of 12 months. CONCLUSIONS: The management of scalp AVMs can be challenging; therefore, focused, and accurate identification of the complexity of the vascular anatomy is required. The combined method of preoperative EE and SE showed satisfactory outcomes with low rates of complications and recurrence; thus, we recommend this approach for the management of scalp AVMs.

Macrocheilia as an Atypical Clinical Presentation of Capillary Malformation-Arteriovenous Malformation Type 2.

This case report describes a 53-year-old man with multiple erythematous macules and papules diffusely distributed on the frontal area, cheeks, eyelids, nose, and supralabial skin.

Hereditary hemorrhagic telangiectasia: from signaling insights to therapeutic advances.

Hereditary hemorrhagic telangiectsia (HHT) is an inherited vascular disorder with highly variable expressivity, affecting up to 1 in 5,000 individuals. This disease is characterized by small arteriovenous malformations (AVMs) in mucocutaneous areas (telangiectases) and larger visceral AVMs in the lungs, liver, and brain. HHT is caused by loss-of-function mutations in the BMP9-10/ENG/ALK1/SMAD4 signaling pathway. This Review presents up-to-date insights on this mutated signaling pathway and its crosstalk with proangiogenic pathways, in particular the VEGF pathway, that has allowed the repurposing of new drugs for HHT treatment. However, despite the substantial benefits of these new treatments in terms of alleviating symptom severity, this not-so-uncommon bleeding disorder still currently lacks any FDA- or European Medicines Agency-approved (EMA-approved) therapies.

Shear Stress and Sub-Femtomolar Levels of Ligand Synergize to Activate ALK1 Signaling in Endothelial Cells.

Endothelial cells (ECs) respond to concurrent stimulation by biochemical factors and wall shear stress (SS) exerted by blood flow. Disruptions in flow-induced responses can result in remodeling issues and cardiovascular diseases, but the detailed mechanisms linking flow-mechanical cues and biochemical signaling remain unclear. Activin receptor-like kinase 1 (ALK1) integrates SS and ALK1-ligand cues in ECs; ALK1 mutations cause hereditary hemorrhagic telangiectasia (HHT), marked by arteriovenous malformation (AVM) development. However, the mechanistic underpinnings of ALK1 signaling modulation by fluid flow and the link to AVMs remain uncertain. We recorded EC responses under varying SS magnitudes and ALK1 ligand concentrations by assaying pSMAD1/5/9 nuclear localization using a custom multi-SS microfluidic device and a custom image analysis pipeline. We extended the previously reported synergy between SS and BMP9 to include BMP10 and BMP9/10. Moreover, we demonstrated that this synergy is effective even at extremely low SS magnitudes (0.4 dyn/cm2) and ALK1 ligand range (femtogram/mL). The synergistic response to ALK1 ligands and SS requires the kinase activity of ALK1. Moreover, ALK1's basal activity and response to minimal ligand levels depend on endocytosis, distinct from cell-cell junctions, cytoskeleton-mediated mechanosensing, or cholesterol-enriched microdomains. However, an in-depth analysis of ALK1 receptor trafficking's molecular mechanisms requires further investigation.

Use of Polyurethane-Covered Stents for Exclusion of Pulmonary Arteriovenous Malformations.

PURPOSE: To evaluate the safety, technical success and short-term effectiveness of polyurethane-covered stent (PK Papyrus, BioTronik, Berlin) in the treatment of pulmonary arteriovenous malformations (PAVMs) that are not amenable to embolotherapy. MATERIALS AND METHODS: In this IRB-approved, retrospective study, data from patients who received polyurethane-covered stents for exclusion of PAVMs were analyzed. The study included 5 patients (all women) with a median age of 40 years (range 25-60). Patients presented with hypoxemia, TIAs, and/or epistaxis; 4 were confirmed to have HHT. All had multiple PAVMs diagnosed on chest CT and underwent embolization with other devices in addition to the polyurethane-covered stent. The indication for stent placement in all cases was a short and/or tortuous feeding artery. Safety was assessed by immediate or short-term complications, e.g., migration, stent thrombosis, and fracture. Technical success was defined as the ability to accurately place the stent at the intended location. Effectiveness was defined as successful exclusion of PAVM with no perfusion across the AVM. RESULTS: Technical success of stent placement was 100%. AVM exclusion rate was 80% after single stent deployment; in the case of incomplete exclusion, success was achieved using an overlapping stent to completely cover a second feeding artery. During the median follow-up period of 5 months (range 2-10), all stents remained patent, and AVMs were excluded without other complications. CONCLUSION: Exclusion of PAVMs with polyurethane-covered stents is technically feasible, safe, and shows short-term effectiveness for PAVMs with a short/tortuous feeding artery when traditional embolization techniques are not possible.