Arteriovenous Malformations Research Articles

Evaluation of micro-remnant niduses of arteriovenous malformations post-gamma knife radiosurgery by 3D-rotational angiography.

Recent innovations in radiological imaging have enabled the detection of micro-remnant niduses of arteriovenous malformations (AVMs) after gamma knife radiosurgery (GKS), which have not been previously perceptible. Herein, we focus on the difficulty of evaluating micro-remnant AVMs after GKS that are hardly perceptible on conventional examinations and propose integrating follow-up three-dimensional rotational angiography (3D-RA) in the previous gamma plan as a solution. We retrospectively searched NTT Medical Center Tokyo hospital database for patients with AVMs who underwent both two-dimensional digital subtraction angiography (2D-DSA) and 3D-RA as follow-up for GKS from February 2021 to January 2024. Patients with suspected nidus occlusion on the latest non-contrast-enhanced magnetic resonance angiography (NC-MRA) were included, and contrast-enhanced magnetic resonance angiography (CE-MRA), 2D-DSA, and 3D-RA were evaluated. Twelve patients with 13 AVM sites were defined as having complete nidus occlusion on upfront NC-MRA. On 2D-DSA, seven AVM sites showed the presence of slight remaining AVMs based on the detection of remnant drainage veins, however the nidus was not detected in three cases. Nevertheless, 3D-RA detected micro-remnant niduses in all seven AVM sites, and four patients underwent re-GKS. Nine patients with ten AVM sites also underwent CE-MRA, and six AVM sites were diagnosed with radiation-induced parenchymal injury. Importing the 3D-RA image into the treatment planning has the potential to be more helpful than NC-MRA or CE-MRA to detect micro-remnant AVMs and evaluate the true remnant volume, and may contribute to a more detailed treatment planning, thereby improving the results of GKS retreatment.

Considerations for the Use of Stereotactic Radiosurgery to Treat Large Arteriovenous Malformations.

Stereotactic radiosurgery (SRS) is an effective treatment strategy for cerebral arteriovenous malformations (AVMs). Aggressive treatment achieving complete obliteration is necessary to prevent further intracranial hemorrhage and neurological deficits. However, SRS treatment of large AVMs (>10 cm3) is challenging. To prevent toxicity in the normal brain tissue, it is imperative to reduce the radiation dose as the lesion volume increases; however, this also reduces the rate of obliteration. In this study, we review the various radiosurgical approaches for treating large AVMs and their outcomes, and suggest ways to improve treatment outcomes during SRS for large AVMs.

Obstetric management for pregnant women with Klippel-Trenaunay syndrome: A UK case report and review of the literature.

Klippel-Trenaunay Syndrome (KTS) is a rare congenital vascular disorder characterized by extensive capillary and venous malformations that pose unique challenges during pregnancy. This case report discusses the successful management of a 34-year-old pregnant woman with KTS who had two caesarean sections, resulting in the birth of two healthy babies. Despite the lack of evidence-based guidelines for obstetrical management in KTS, a multidisciplinary team collaborated to devise a high-risk thrombosis management plan, involving the use of compression stocking and low molecular weight heparin prophylaxis. The patient's elevated risk of thrombosis, exacerbated during pregnancy, informed the decision of caesarean sections, aligning with finding that in most KTS pregnancies, this method of delivery based on obstetric indications and arteriovenous malformations is chosen. This case highlights the importance of systematic and patient-centered care, advocating for comprehensive obstetric management guidelines to address the unique challenges posed by KTS during pregnancy. Further research is warranted to enhance our understanding and refine guidelines for individuals with vascular abnormalities linked to KTS.

Outcome of early versus late primary embolization in ruptured brain arteriovenous malformations.

To determine whether patients with a ruptured brain arteriovenous malformation (rBAVM) would benefit from an early embolization. rBAVM treated first by embolization between March 2002 and May 2022 were included. Embolization was defined early (Group 1) when performed within 10 days postbleeding. If later, embolization was considered late (Group 2). Demographic and rBAVM data were compared between the groups. High-risk bleeding components and reasons for deferring embolization were retrieved. Primary endpoint was rebleeding. Secondary endpoints were good functional outcome (FO, modified Rankin Scale mRS ≤ 2) and angiographic occlusion. Predictors of rebleeding and FO were determined by multivariate analysis. 105 patients were recruited (N = 34 in Group 1; N = 71 in Group 2). No rebleeding was noted before, during or after the first embolization session in the early embolization group. Late embolization depended on missed diagnosis and referral pattern. Eleven patients (10.5%) suffered a rebleeding, of whom N = 3 before embolization (only in Group 2), N = 5 periembolization (N = 2 at the second embolization session in Group 1) and N = 3 spontaneous more than 30 days postembolization. More high-risk components were embolized in Group 1 (19/34; 55.9 vs 17/71; 23.9%; p = .011). Rebleeding rates, FO at last FU (90.9% vs 74.3%) and occlusion rates (80.8% vs 88.5%) did not differ between the groups. Glasgow coma scale ≤ 8 predicted rebleeding, rebleeding correlated with poor FO. Early embolization did prevent rebleeding. The overall rebleeding risk was linked to bleeding before late embolization and bleeding at the second embolization. Rebleeding predicted the final FO.

High-intensity Focused Ultrasound Ablation Combined with Hysteroscopy for the Treatment of Uterine Arteriovenous Fistula Associated with Retained Products of Conception: A Prospective Cohort Study

To evaluate the efficacy of combining high-intensity focused ultrasound (HIFU) ablation with hysteroscopic removal of retained products of conception in the presence of a uterine arteriovenous fistula (UAVF). Prospective cohort study SETTING: Tertiary hospital. 17 patients with UAVF and retained products of conception. HIFU ablation combined with hysteroscopic removal of retained products of conception RESULTS: All patients presented with irregular vaginal bleeding following pregnancy termination and not responsive to medical treatment. Patients were confirmed to have a UAVF along with concurrent intrauterine residue using three-dimensional color Doppler ultrasonography, uterine angiography, or pelvic-enhanced magnetic resonance imaging; and demonstrated a poor response to medical treatment. Under real-time ultrasound guidance, HIFU was used to ablate the arteriovenous malformation region. Patients underwent hysteroscopic removal of retained products of conception; the removed tissue was subjected to pathological examination. All patients underwent monthly uterine color Doppler ultrasound examinations and menstrual status follow-up within 3 months postoperatively and showed normal menstrual recovery without signs of arteriovenous malformations on ultrasonography. Pathological examination of the tissues removed during hysteroscopic clearance revealed characteristics consistent with pregnancy, with abnormal blood vessels in some tissues. All patients experienced normal menstrual recovery postoperatively, without intrauterine adhesions. Combining HIFU ablation with postoperative hysteroscopic surgery effectively treats pregnancy related UAVF with minimal complications, preserves fertility; it offers an additional treatment option for patients wanting future fertility.

Genetic Analysis of Cerebrovascular Diseases

With advances in genetic analysis technology, the genetic and molecular backgrounds of cerebrovascular diseases have become clearer. In moyamoya disease and intracranial artery stenosis, RNF213 p.Arg4810Lys has been identified as a disease susceptibility gene variant(germline variant), and various analyses have been conducted. PDGFRB mutations have been identified as characteristic somatic variants in cerebral aneurysms and are attracting attention. In addition, PIK3CA and MAP3K3 mutaions have been identified in cerebral cavernous malformations as somatic variants. Moreover, KRAS and BRAF mutations have been identified in arteriovenous malformations as somatic variants, respectively. Further studies are in progress. We reviewed the results of recent genetic analyses of cerebrovascular diseases, focusing particularly on genetic mutations.

Surgical treatment and outcome of spinal arteriovenous malformations

Surgical treatment and outcome of spinal arteriovenous malformations

Akt is a mediator of artery specification during zebrafish development.

The dorsal aorta (DA) is the first major blood vessel to develop in the embryonic cardiovascular system. Its formation is governed by a coordinated process involving the migration, specification, and arrangement of angioblasts into arterial and venous lineages, a process conserved across species. Although vascular endothelial growth factor a (VEGF-A) is known to drive DA specification and formation, the kinases involved in this process remain ambiguous. Thus, we investigated the role of protein kinase B (Akt) in zebrafish by generating a quadruple mutant (aktΔ/Δ), in which expression and activity of all Akt genes - akt1, -2, -3a and -3b - are strongly decreased. Live imaging of developing aktΔ/Δ DA uncovers early arteriovenous malformations. Single-cell RNA-sequencing analysis of aktΔ/Δ endothelial cells corroborates the impairment of arterial, yet not venous, cell specification. Notably, endothelial specific expression of ligand-independent activation of Notch or constitutively active Akt1 were sufficient to re-establish normal arterial specification in aktΔ/Δ. The Akt loss-of-function mutant unveils that Akt kinase can act upstream of Notch in arterial endothelial cells, and is involved in proper embryonic artery specification. This sheds light on cardiovascular development, revealing a mechanism behind congenital malformations.

Pulmonary Arteriovenous Malformation in a Young Man

ABSTRACT A young man was diagnosed to have pulmonary arteriovenous malformation (PAVM) when he was admitted with COVID infection. He had no respiratory distress but his saturation at room air was 90%. Chest X-ray revealed non-homogenous opacity in left lower lobe (LLL). The heart was structurally normal on 2D echocardiography; the saline bubble study was however positive for extra-cardiac shunt. Computed tomography pulmonary angiography (CTPA) revealed PAVM with well-defined lobulated sac measuring 2.9 × 1.9 × 2.5 cm in lateral basal segment of LLL with segmental branch of left pulmonary artery as feeder vessel and it drained into left pulmonary vein. The patient was managed with percutaneous intervention using Amplatzer Vascular Plug II to occlude the feeder vessel. Post-intervention, patient’s saturation improved to 98% at room air and saline bubble study was negative for extra-cardiac shunt. CTPA at 06 weeks revealed complete thrombosis of the sac.

SÍNDROME DE RENDU-OSLER-WEBER E APLASIA MEDULAR TRANSITÓRIA ASSOCIADA AO PARVOVÍRUS B19: RELATO DE CASO

Hereditary hemorrhagic telangiectasia, also known as Rendu-Osler-Weber syndrome, is an uncommon genetic disease characterized by arteriovenous malformations mainly in skin and mucous membranes, but also in visceral organs, lungs and even central nervous system, causing intermittent hemorrhagic episodes, some of them potentially severe. Their main consequence is iron deficiency anemia. Parvovirus b19 is a DNA virus with proerythroblast tropism whose infection is generally asymptomatic, but might cause cutaneous manifestations, such as infectious erythema, articular symptoms and medullary aplasia, rarely seen in immunocompetent individuals. The aim of this study is to demonstrate the association of these two diseases and their potential correlation. In this report we describe a 54 years old woman with a history of epistaxis since childhood, who presented worsening hemorrhagic episodes, melena, dyspnea at rest and pancytopenia. During investigation the diagnosis of Rendu-Osler-Weber syndrome was made, and posteriorly it was identified that her clinical worsening and pancytopenia was caused by medullary aplasia associated to parvovirus b19infection.

Scalp Arteriovenous Malformation. Percutaneous Multistage Ligature under Ultrasound Guidance: Palliative Technique to be Considered. Case report.

Background: Scalp arteriovenous malformations (AVMs) are fast-flow malformations characterized by the presence of arteriovenous shunting without an intervening capillary bed within the subcutaneous layer. Aim: To report a case of AVMs managed by percutaneous multistage ligature under ultrasound guidance. Case report: A 68-year-old patient with a AVMs was managed by percutaneous multistage ligature under ultrasound guidance with acceptable cosmetic and functional results. Conclusion: Some patients with bad health conditions and a high risk of anesthesia with comorbidities can benefit from multistage transcutaneous ligation of the principal arterial pedicular under ultrasound guidance. This simple and palliative technique must be considered in some cases.

Unforeseen outcomes: Unveiling cyst formation post stereotactic radiosurgery in brain arteriovenous malformations cases

IntroductionCyst formation after stereotactic radiosurgery (SRS) for brain arteriovenous malformations (AVMs) is a rare, delayed but important complication. Prompt recognition and appropriate treatment is essential for good outcome. MethodsWe analysed our institute’s Gamma knife treatment records from 2008 to 2023 and analysed AVM treated patients by gamma knife radiosurgery (GKRS). Patients with cyst formation and with adequate follow up were identified. Clinical details, management and prognosis of these patients was studied in detail along with prior literature review. ResultsA total of 921 AVM patients were treated in the above period and 7 patients were identified with cyst formation. The mean nidus volume was 12.98 ml, the mean radio surgical marginal dose was 23.57 Gy and maximal dose 47.21 Gy. The mean interval gap between SRS and cyst detection was 6.45 years. The mean volume of cyst cavity formed was 47.85 ml. Patients presented either with features of raised intracranial pressure (3) or focal neurological deficits (3) or seizures (1). 3 patients had achieved angiographic nidus obliteration at the time of cyst detection. Treatment was mostly on surgical lines with cyst fenestration(2 patients), excision (3 patients) and emergency decompressive craniectomy (1 patient). 1 patient required additional Ommaya insertion. Conservative management was followed for 1 patient. Residual nidus was treated either by concomitant excision or embolization or redo GKRS.Favourable outcome was seen in 6 out of 7 patients (85.71%) post cyst management with symptomatic and radiological improvement whereas 1 patient (14.28%) died due to refractory status epilepticus secondary to malignant cerebral edema. ConclusionCyst formation after GKRS for AVM treatment is an often-neglected complication due to its low incidence and often long latency period. Long term follow up of patients is hence necessary for prompt recognition. Diagnostic DSA should be done in all patients with cysts to look for residual nidus. Asymptomatic ones can be followed up conservatively while surgical treatment is required for symptomatic cases. Ventricular diversion like Ommaya or cystoperitoneal shunt may be necessary in some cases. Treatment outcome is usually favourable provided timely detection is done.

Rupture risk assessment in cerebral arteriovenous malformations: an ensemble model using hemodynamic and morphological features

BackgroundCerebral arteriovenous malformation (AVM) is a cerebrovascular disorder posing a risk for intracranial hemorrhage. However, there are few reliable quantitative indices to predict hemorrhage risk accurately. This study aimed to...

Diagnostic accuracy of arterial spin labeling MR imaging in detecting cerebral arteriovenous malformations: a systematic review and meta-analysis.

Diagnostic accuracy of arteriovenous malformations (AVMs) is imperative for delineating management. The current standard is digital subtraction angiography (DSA). Arterial spin labeling (ASL) is an understudied noninvasive, non-contrast technique that allows angioarchitecture visualization and additionally quantifies cortical and AVM cerebral blood flow and hemodynamics. This meta-analysis aims to compare ASL and DSA imaging in detecting and characterizing cerebral AVMs. EMBASE, Medline, Scopus, and Cochrane databases were queried from inception to July 2022 for reports of AVMs evaluated by DSA and ASL imaging. Fourteen studies with 278 patients evaluated using DSA and ASL imaging prior to intervention were included; pCASL in 11 studies (n = 239, 85.37%) and PASL in three studies (n = 41, 14.64%). The overall AVM detection rate on ASL was 99% (CI 97-100%); subgroup analysis revealed no difference between pCASL vs. PASL (99%; CI 96-100% vs. 100%; CI 95-100% respectively, p = 0.42). The correlation value comparing ASL and DSA nidus size was 0.99. DSA and ASL intermodality agreement Cohen's k factor for Spetzler Martin Grading (SMG) was reported at a median of 0.98 (IQR 0.73-0.1), with a 1.0 agreement on SMG classification. A median of 25 arteries were detected by DSA (IQR 14.5-27), vs. 25 by ASL (IQR 14.5-27.5) at a median 0.92 k factor. ASL provides angioarchitectural visualization noninferior to DSA and additionally quantifies CBF. Our study suggests that ASL should be considered in the detection of AVMs, especially in patients with contrast contraindications or apprehension towards an invasive assessment.

Diagnosis on dilemma: Arteriovenous malformation with scar pregnancy with old retained product of conception

Cesarean scar pregnancy (CSP) is described as the placement of a gestational sac within the scar from a previous cesarean operation and is considered an ectopic pregnancy. Ectopic pregnancy situated in a cesarean section scar is a rare but potentially life-threatening event. Because of its rarity, there are no universal guidelines to manage this condition. CSP has no pathognomonic signs or symptoms and its presentation varies considerably. Here, we report a case of scar pregnancy containing an old retained product of conceptus.

Pediatric interventional neuroradiology: "How I do it" vol. II-Embolization.

Pediatric arteriovenous shunts can be challenging to embolize and the consequences of excess venous penetration disastrous. Moreover, the congenital nature of most shunts necessitates neonatal intervention whenever (medically refractory) heart failure occurs. Here, we describe current endovascular treatment strategies based on personal experience and literature review. While disparate, arteriovenous malformation, dural arteriovenous fistula (AVF), pial AVF, and vein of Galen aneurysmal malformation share unifying features such as high output heart failure and venous hypertension. This tutorial is divided into passages on Goals, Access, and Treatment which respect differences among pediatric arteriovenous shunts while maintaining a narrative economy.

Flank pain, hypertension, and hematuria: CT and 3D cinematic rendering in the evaluation of renal artery emergencies-a pictorial essay.

Non-traumatic acute renal artery emergencies encompass a spectrum of etiologies, including renal artery stenosis, arteriovenous malformations, aneurysms and pseudoaneurysms, dissections, thrombosis, and vasculitis. Prompt and accurate diagnosis in the emergency setting is crucial due to the potential for significant morbidity and mortality. Computed tomography (CT) and CT angiography (CTA) are the mainstay imaging modalities, offering rapid acquisition and high diagnostic accuracy. The integration of 3D postprocessing techniques, such as 3D cinematic rendering (CR), improves the diagnostic workflow by providing photorealistic and anatomically accurate visualizations. This pictorial essay illustrates the diagnostic utility of CT and CTA, supplemented by 3D CR, through a series of 10 cases of non-traumatic renal artery emergencies. The added value of 3D CR in improving diagnostic confidence, surgical planning, and understanding of complex vascular anatomy is emphasized.

Arteriovenous Malformations in Osler-Weber-Rendu Syndrome: Pathophysiology, Clinical Manifestations, and Advances in Management

Osler-Weber-Rendu Syndrome, or Hereditary Hemorrhagic Telangiectasia (HHT), is a rare genetic disorder marked by the development of arteriovenous malformations (AVMs) throughout the body. These abnormal vascular connections bypass the capillary network, leading to significant clinical challenges. This article reviews the pathophysiology, clinical manifestations, and advances in the management of AVMs in HHT. The genetic basis of HHT involves mutations in the ENG, ACVRL1, and SMAD4 genes, which play critical roles in the TGF-β signaling pathway. These mutations result in endothelial dysfunction, contributing to the formation of AVMs. The clinical impact of AVMs is significant, particularly when they occur in the brain, lungs, liver, or gastrointestinal tract, where they can lead to life-threatening complications. This review also explores current diagnostic and management strategies, emphasizing the importance of a multidisciplinary approach. Interventional techniques such as embolization, stereotactic radiosurgery, and microsurgical resection are discussed, alongside emerging therapies like anti-angiogenic drugs and gene therapy. These advancements have led to more personalized and effective treatment plans for patients. As a result, the management of AVMs in HHT has seen significant progress, with a growing emphasis on individualized care. Continued research and the development of specialized treatment centers are crucial for further improving patient outcomes in this complex condition.

Ultra-early neurological deterioration following a brain arteriovenous malformation rupture.

This study aims to explore the impact of ultra-early neurological deterioration (U-END) on the outcome (mortality and poor neurological status) following a brain arteriovenous malformation (BAVM) rupture and identify determinants of U-END. Patients with BAVM ruptures admitted to a single tertiary care center were retrospectively reviewed. U-END was defined as a worsening by two or more points on the Glasgow Coma Scale (GCS). U-END was tested as a potential predictor of in-hospital mortality and poor outcomes. Univariate and multivariate analyses were performed to identify determinants of U-END. Patients with U-END were also matched and compared with BAVM rupture controls presenting with a GCS close or equal to either their initial or their lowest GCS. A total of 248 patients with BAVM ruptures met the inclusion criteria, with 39 (15.7%) patients presenting with U-END. U-END was not associated with and was not an independent predictor of in-hospital mortality (12.8 vs. 10.5% in the rest of the study population; p = 0.67) or poor outcomes (39.5 vs. 36.9%; p = 0.77). The only independent determinants of U-END were hydrocephalus (OR 2.6 [95%CI, 1.1-6.4]; p = 0.03) and intraventricular hemorrhage (IVH; OR 3.5 [95%CI, 1.1-11.7]; p = 0.04). When compared to the initial GCS control group, U-END patients more often presented with IVH (89.5 vs. 64.1%; p = 0.009) and hydrocephalus (73 vs. 38.5%; p = 0.003). When compared to the lowest GCS control group, U-END patients had lower early S100B serum levels (0.35 ± 0.37 vs. 0.83 ± 1; p = 0.009) and a lower rate of poor outcome (39.5 vs. 64.9%; p = 0.03). Ultra-early neurological deterioration in ruptured BAVMs did not result in increased mortality or poor outcomes and was most often related to IVH and hydrocephalus.

Stereotactic Radiosurgery With Versus Without Neoadjuvant Endovascular Embolization for Brain Arteriovenous Malformations With Associated Intracranial Aneurysms.

Stereotactic radiosurgery (SRS) with neoadjuvant embolization is a treatment strategy for brain arteriovenous malformations (AVMs), especially for those with large nidal volume or concomitant aneurysms. The aim of this study was to assess the effects of pre-SRS embolization in AVMs with an associated intracranial aneurysm (IA). The International Radiosurgery Research Foundation AVM database from 1987 to 2018 was retrospectively reviewed. SRS-treated AVMs with IAs were included. Patients were categorized into those treated with upfront embolization (E + SRS) vs stand-alone SRS (SRS). Primary end point was a favorable outcome (AVM obliteration + no permanent radiation-induced changes or post-SRS hemorrhage). Secondary outcomes included AVM obliteration, mortality, follow-up modified Rankin Scale, post-SRS hemorrhage, and radiation-induced changes. Forty four AVM patients with associated IAs were included, of which 23 (52.3%) underwent pre-SRS embolization and 21 (47.7%) SRS only. Significant differences between the E + SRS vs SRS groups were found for AVM maximum diameter (1.5 ± 0.5 vs 1.1 ± 0.4 cm3, P = .019) and SRS treatment volume (9.3 ± 8.3 vs 4.3 ± 3.3 cm3, P = .025). A favorable outcome was achieved in 45.4% of patients in the E + SRS group and 38.1% in the SRS group (P = .625). Obliteration rates were comparable (56.5% for E + SRS vs 47.6% for SRS, P = .555), whereas a higher mortality rate was found in the SRS group (19.1% vs 0%, P = .048). After adjusting for AVM maximum diameter, SRS treatment volume, and maximum radiation dose, the likelihood of achieving favorable outcome and AVM obliteration did not differ between groups (P = .475 and P = .820, respectively). The likelihood of a favorable outcome and AVM obliteration after SRS with neoadjuvant embolization in AVMs with concomitant IA seems to be comparable with stand-alone SRS, even after adjusting for AVM volume and SRS maximum dose. However, the increased mortality among the stand-alone SRS group and relatively low risk of embolization-related complications suggest that these patients may benefit from a combined treatment approach.