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Introduction: Brain arteriovenous malformations (bAVMs) present complex challenges in neurosurgery, requiring precise pre-surgical planning. In this context, 3D printing technology has emerged as a promising tool to aid in understanding bAVM morphology and enhance surgical outcomes, particularly in pediatric patients. This study aims to assess the feasibility and effectiveness of using 3D AVM models in pediatric bAVM surgery., Methodology: The study was conducted at Great Ormond Street Hospital, and cases were selected sequentially between October 2021 and February 2023. Eight pediatric bAVM cases with 3D models were compared to eight cases treated before the introduction of 3D printing models. The 3D modelling fidelity and clinical outcomes were assessed and compared between the two cohorts., Results: The study demonstrated excellent fidelity between 3D models and actual operative anatomy, with a median difference of only 0.31 mm. There was no statistically significant difference in angiographic cure rates or complications between the 3D model group and the non-3D model group. Surgical time showed a non-significant increase in cases involving 3D models. Furthermore, the 3D model cohort included higher-grade bAVMs, indicating increased surgical confidence., Conclusion: This study demonstrates the feasibility and efficacy of utilizing 3D AVM models in pediatric bAVM surgery. The high fidelity between the models and actual operative anatomy suggests that 3D modelling can enhance pre-surgical planning and intraoperative guidance without significantly increasing surgical times or complications. Further research with larger cohorts is warranted to confirm and refine the application of 3D modelling in clinical practice., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Arteriovenous malformations (AVMs) are direct communications between primitive reticular networks of dysplastic vessels that have failed to mature into capillary vessels. Based on angiographic findings, peripheral AVMs can be classified into six types: type I, type IIa, type IIb, type IIc, type IIIa, and type IIIb. Treatment strategies vary with the types. Type I is treated by embolizing the fistula between the artery and the vein with coils. Type II (IIa, IIb, and IIc) AVM is treated as follows: first, reduce the blood flow velocity in the venous segment of the AVM with coils; second, perform ethanol embolotherapy of the residual shunts. Type IIIa is treated by transarterial catheterization of the feeding arteries and injection of diluted ethanol. Type IIIb is treated by transarterial or direct puncture approaches. A high concentration of ethanol is injected through the transarterial catheter or direct puncture needle. When the fistula is large, coil insertion is required to reduce the amount of ethanol. Type I and type II AVMs showed the best clinical results; type IIIb showed a satisfactory response rate. However, type IIIa showed the poorest response rate, either alone or in combination with other types. Clinical success can be achieved by using different treatment strategies for different angiographic AVM types., Competing Interests: The authors have no potential conflicts of interest to disclose., (Copyright © 2021 The Korean Society of Radiology.)

Purpose: To evaluate endovascular treatment of head and neck arteriovenous malformations (AVMs) based on the Yakes AVM classification and correlate treatment approach with clinical and angiographic outcomes., Materials and Methods: A retrospective single-center study was performed in patients who underwent endovascular treatment of head and neck AVMs between January 2005 and December 2017. Clinical and operative records, imaging, and postoperative courses of patients were reviewed. Clinical stage was determined according to the Schobinger classification. AVM architecture and treatment approaches were determined according to the Yakes classification. Primary outcomes were clinical and angiographic treatment success rates and complication rates, with analysis according to the Yakes classification., Results: A total of 29 patients (15 females) were identified, with a mean age of 30.6 years. Downgrading of the Schobinger clinical classification was achieved in all patients. Lesions included 8 Yakes type IIa, 5 type IIb, 1 type IIIa and IIIb, and 14 type IV. Lesions were treated using an intra-arterial, nidal, or transvenous approach, using ethanol and liquid embolic agents. Arteriovenous shunt eradication of >90% was achieved in 22 of 28 patients (79%), including 9 of 13 (69%) of Yakes type IV lesions and 13 of 15 (87%) of the other types. There were 5 significant complications in 79 procedures (6%), including 4 of 50 (8%) in Yakes type IV lesions., Conclusions: Schobinger stage was downgraded in all patients. Arteriovenous shunt eradication of >90% was achieved in most patients. Yakes type IV lesions required more sessions, and shunt eradication was higher in the Yakes II and III groups., (Copyright © 2020 SIR. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate the characteristics of intraretinal microvascular abnormalities (IRMAs) before and after panretinal photocoagulation (PRP) for diabetic retinopathy (DR) by using optical coherence tomography angiography (OCTA)., Methods: Forty-six eyes of 29 patients with DR were included (26 eyes with severe nonproliferative diabetic retinopathy [SNPDR] and 20 eyes with proliferative diabetic retinopathy [PDR]). En face OCTA images of IRMAs in a 6 × 6-mm area were acquired by using Cirrus 5000 with AngioPlex. The morphological changes in IRMAs were evaluated before and after PRP. The changes in the IRMAs were divided into five subtypes: unchanged; tuft regression; reperfusion; mixed (combined tuft regression/reperfusion); and worsening (new appearance of tuft)., Results: Unchanged IRMAs were identified in 15 SNPDR eyes and 2 PDR eyes; all neovascularization (NV) had regressed after PRP. Tufts were more frequently observed in the PDR eyes (15/20, 75%) than in the SNPDR eyes (8/26, 31%) (P = 0.003), and two tufts tended to exceed the inner limiting membrane, which showed progression to NV before PRP. The reperfusion phenomenon was observed in 7/26 SNPDR eyes and 4/20 PDR eyes, including the mixed type, and showed two vascular patterns: abnormal (dilated, tortuous, and twisted) and normal vessels. The worsening type was observed in 1/26 SNPDR eye and 2/20 PDR eyes., Conclusions: OCTA enabled classification of IRMA into more detailed types. The unchanged and reperfusion types suggested that IRMAs had aspects of remodeling. However, IRMAs with tufts were observed in 75% of the PDR eyes, and the tufts had aspects of NV.

Purpose: To evaluate the safety and efficacy of ethanol and coil embolization of type II arteriovenous malformation (AVM) according to a new subtype classification., Materials and Methods: Eighty-four type II AVMs in the body or extremity of 79 patients who underwent AVM treatment from 1996 to 2017 were retrospectively subclassified according to the angiographic morphology of the draining vein as type IIa (arterioles shunt to focal segment of single draining vein), type IIb (arterioles shunt to venous sac with multiple draining veins), and type IIc (arterioles shunt along long segment of draining vein). Coil and ethanol embolization of the focal or long segment of the draining vein or the venous sac was performed with direct puncture or transvenous approach according to subtype. Treatment outcomes, number of treatment sessions, and complications were analyzed., Results: AVM cure (ie, complete embolization) rates were 95%, 76%, and 65% in types IIa, IIb, and IIc AVMs, respectively. The cure rate of type IIa AVMs was significantly better than that of type IIc AVMs (P = .015). Median numbers of treatment sessions were 1 in types IIa and IIb AVMs and 2.5 in type IIc AVMs, with a significant difference between type IIc and the other 2 types (P < .05). Minor complications occurred in 20% of patents and major complications occurred in 7%., Conclusions: The cure rate of type IIa AVMs was significantly better than that of type IIc AVMs, which also required significantly more treatment sessions than the other 2 types., (Copyright © 2019 SIR. Published by Elsevier Inc. All rights reserved.)

Treatment of arteriovenous malformations (AVMs) should be individualized based on the imaging findings. A total of 117 AVM cases were categorized into three types based on the angio-architectural characteristics: Type I (n=14, no draining vein or diameter of the draining vein <2mm); Type II (n=64, draining vein diameter 2-6mm); and Type III (n=39, draining vein diameter >6mm). Subjects were randomly allocated to one of two treatment groups: Group A (n=59) received multipoint percutaneous ethanol injection (MPEI), while Group B (n=58) received super-selective angiograms followed by embolization with gelfoam (EFAG) plus MPEI. Patients were followed up for 2-6 years. A significant between-group difference with respect to treatment outcomes was observed only for Type III cases (P<0.05). Direct percutaneous puncture digital-subtraction-angiography-guided classification of AVMs provides easy-to-follow guidelines for its clinical management. EFAG plus MPEI with reduced procedure time and the amount of ethanol should be used for Type III AVMs., (Copyright © 2018. Published by Elsevier Ltd.)

Arterioportal vascular anomalies are communications between the splanchnic arteries and the portal system that represent a rare cause of presinusoidal portal hypertension in small animals. There is little information concerning the imaging findings of arterioportal communications in small animals and no classification could be found for radiologists and surgeons. The aims of this retrospective descriptive multicentric study were to describe the computed tomographic characteristics of arterioportal communications in a group of cats and dogs, and to propose a classification based on computed tomography (CT) angiographic anatomy. Computed tomography databases from multiple veterinary hospitals were searched for cats and dogs with a diagnosis of arterioportal communication. A total of 36 animals (33 dogs, three cats) met the inclusion criteria. There were 32 intrahepatic arterioportal malformations and four extrahepatic fistulae. The intrahepatic arterioportal malformations were classified as right divisional (11/32) and left divisional (21/32), and the left divisional were subclassified as left medial (16/21) and left lateral (4/21). One patient showed multiple intrahepatic arterioportal communications with concomitant left medial and left lateral conformations. Two patients with intrahepatic arteriovenous malformation showed concomitant congenital intrahepatic shunts. The proposed anatomical classification based on CT angiography could allow veterinary radiologists to have a more systematic approach and help improve the radiologist-surgeon communication., (© 2018 The Authors. Veterinary Radiology & Ultrasound published by Wiley Periodicals, Inc. on behalf of American College of Veterinary Radiology.)

Introduction: Arteriovenous malformations (AVMs) are characterized by pathological high flow, low resistance connections between arteries and veins. Treatment is critically dependent on correct interpretation of angioarchitectural features. However, some microfistular AVMs do not match the characteristics described in current AVM classification systems. Therefore, we propose a new subgroup of microfistular AVMs, composed of enlarged, fistulous paths on the venous half of capillaries and/or dilated draining venules (hyperdynamic, capillary-venulous malformation [CV-AVM]). CV-AVMs still ensure arterial flow to the periphery and fistulous venous drainage is less pronounced than in classical AVMs such that these lesions are often misinterpreted as venous malformations., Materials and Methods: We developed a computational model to study the effects of microvascular anomalies on local hemodynamics, as well as their impact on angiographic contrast propagation. Flow rates and pressures were computed with a lumped parameter description, while contrast propagation was determined by solving the 1D advection-diffusion equation., Results and Conclusions: For the newly proposed CV-AVM angioarchitecture, the computational model predicts increased arterio-venous contrast agent transit times and highly dispersive transport characteristics, compared to microfistular, interstitial type IV AVMs and high flow type II and III AVMs. We related these findings to time-contrast intensity curves sampled from clinical angiographies and found that there is strong evidence for the existence of CV-AVM., Competing Interests: The authors have declared that no competing interests exist.

Background:  Vascular anomalies are a diagnostic and therapeutic challenge. They require dedicated interdisciplinary management. Optimal patient care relies on integral medical evaluation and a classification system established by experts in the field, to provide a better understanding of these complex vascular entities., Method:  A dedicated classification system according to the International Society for the Study of Vascular Anomalies (ISSVA) and the German Interdisciplinary Society of Vascular Anomalies (DiGGefA) is presented. The vast spectrum of diagnostic modalities, ranging from ultrasound with color Doppler, conventional X-ray, CT with 4 D imaging and MRI as well as catheter angiography for appropriate assessment is discussed., Results:  Congenital vascular anomalies are comprised of vascular tumors, based on endothelial cell proliferation and vascular malformations with underlying mesenchymal and angiogenetic disorder. Vascular tumors tend to regress with patient's age, vascular malformations increase in size and are subdivided into capillary, venous, lymphatic, arterio-venous and combined malformations, depending on their dominant vasculature. According to their appearance, venous malformations are the most common representative of vascular anomalies (70 %), followed by lymphatic malformations (12 %), arterio-venous malformations (8 %), combined malformation syndromes (6 %) and capillary malformations (4 %)., Conclusion:  The aim is to provide an overview of the current classification system and diagnostic characterization of vascular anomalies in order to facilitate interdisciplinary management of vascular anomalies., Key Points:   · Vascular anomalies are comprised of vascular tumors and vascular malformations, both considered to be rare diseases.. · Appropriate treatment depends on correct classification and diagnosis of vascular anomalies, which is based on established national and international classification systems, recommendations and guidelines.. · In the classification, diagnosis and treatment of congenital vascular anomalies, radiology plays an integral part in patient management.., Citation Format: · Sadick M, Müller-Wille R, Wildgruber M et al. Vascular Anomalies (Part I): Classification and Diagnostics of Vascular Anomalies. Fortschr Röntgenstr 2018; 190: 825 - 835., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (© Georg Thieme Verlag KG Stuttgart · New York.)

Superficial vascular anomalies constitute a large group of malformative and tumoral conditions developed from all types of vessels. Vascular tumors are the result of cellular hyperplasia, whereas vascular malformations (VMs) are constituted of dysplastic vessels. The classification from International Society for the Study of Vascular Anomalies (ISSVA) is based on this pathogenic difference. The most common vascular tumor is infantile hemangioma, which treatment, when necessary, is propranolol. Congenital hemangiomas and tumors that might be complicated with Kasabach-Merritt phenomenon, i.e. deep thrombocytopenia, are much rarer. Management of Kasabach-Merritt phenomenon is now largely based on sirolimus. Low-flow VMs include capillary, venous and lymphatic malformations; arteriovenous malformations are high-flow malformations. These different types of VMs might be combined. Currently, there is an increasing work in delineating the different entities based on molecular findings. Treatment of VMs depends on the impairment linked to them, and is decided case by case, in pluridisciplinary consultations. Interventional treatments, especially surgery and sclerotherapy, are usually partially efficient, and management of patients with VMs increasingly involves medical drugs. First-line treatment of coagulation disorders associated with venous malformations is based on low molecular weight heparin; sirolimus seems efficient in hemorrhagic complications refractory to usual treatment. Sirolimus is about to become the standard treatment in painful inflammatory manifestations of mixed and/or complicated lymphatic malformations., (Copyright © 2018 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.)

Accurate histopathologic description in correlation with clinical and radiological evaluation is required for treatment of vascular anomalies, both neoplastic and malformative. It is important to examine current clinical, histologic, and immunophenotypical features that distinguish the major types of congenital and perinatal vascular anomalies affecting the head and neck. General discussions of pathogenesis and molecular diagnosis must also be taken into account. This article provides an overview of the features that distinguish the major types of congenital and perinatal vascular anomalies affecting the head and neck, and summarizes the diagnostic histopathologic criteria and nomenclature currently applied to these lesions., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The purposes of this study were to review historical changes in the classification of spinal arteriovenous (AV) shunts and to propose a practical classification system. The associated literature regarding the classification of spinal AV shunts was reviewed in the angiography era between 1967 and 2015. The classification systems of spinal AV shunts and a proposed classification system were presented with neuroradiological imaging and medical illustrations. There have been seven major classification systems based on the evolution of diagnostic methods as well as treatments for spinal AV shunts: the first description of spinal AV shunts diagnosed and classified using spinal angiography in 1971; the second classification based on a case report of intradural direct perimedullary arteriovenous fistulas (AVFs) treated by microsurgery in 1987; the third classification based on a case series of intradural perimedullary AVFs treated by endovascular interventions in 1993; the fourth and fifth classification systems based on a case series of spinal AVFs and arteriovenous malformations (AVMs) treated by microsurgery or endovascular interventions in 2002; the sixth classification based on a case series of cranio-spinal dural AV shunts in 2009; and the seventh classification based on a case series of extradural AVFs treated by microsurgery and endovascular interventions in 2011. Based on historical reports, the author proposed a classification system according to the sites (dural, intradural, and extradural) and types (AVF and AVM) of AV shunts. By learning the historical background, we may obtain a clearer understanding of the complex and confusing classification system of spinal AV shunts.

Purpose: To evaluate effectiveness and safety of embolization of congenital renal arteriovenous malformations (AVMs) using ethanol and/or coil according to angiographic type., Materials and Methods: Between August 2010 and October 2015, 11 patients (13 sessions; 10 women and 1 man; mean age, 50.8 y) with congenital renal AVMs were treated using ethanol and/or coils via 2 approaches (transarterial access or direct puncture). Demographics, clinical findings, diagnostic modalities, angiographic types, technical and clinical success rates, and complications were reviewed. Renal AVMs were classified into 3 angiographic types, and treatment was based on this classification., Results: Technical success rate was 91% (10/11), and clinical success rate was 100% (11/11). Of patients, 7 had type III AVMs, 3 had type I AVMs, and 1 had type II AVM. Embolic agents were ethanol in 5 patients, coils with ethanol in 3 patients, and coils in 3 patients. Of the 8 patients treated with ethanol, 6 had infarcted renal areas of 3.5%-30% (mean, 14.6%). After a mean follow-up period of 16.3 months, there was no evidence of recurrent AVMs on imaging or laboratory studies., Conclusions: Embolization of congenital renal AVMs via transarterial or direct percutaneous approaches using ethanol and/or coils based on a simple angiographic classification was safe and effective and elicited good outcomes. Most of the patients with congenital renal AVMs were women., (Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.)

Spinal arteriovenous malformations (AVMs) are a diverse population of vascular lesions associated with significant long-term morbidity and neurologic impairment. Spinal AVMs can be classified into three categories: intramedullary, extradural-intradural, and conus, depending on their angioarchitecture and anatomy. Extradural-intradural lesions are typically incurable due to their diffuse nature, but patients may benefit from targeted therapy of symptomatic components. Intramedullary and conus AVMs are amenable to safe surgical resection when combined with endovascular embolization and use of a pial dissection technique that spares entry into the neural parenchyma., (© 2017 Elsevier B.V. All rights reserved.)

Spinal arteriovenous malformations and fistulas comprise spinal vascular malformations (sVMs), a rare but challenging neurosurgic entity. A number of mechanisms have been proposed as explanations of neurologic decline in the setting of arteriovenous shunting, including venous hypertension, venous congestion, hemorrhage, vascular steal, or mass effect, which can be worsened with venous varices or aneurysmal dilations. Anatomic location and features dictate the categorization of sVMs. Two major systems are in place for classification of sVMs - (1) the American/French/English connection and (2) the Spetzler system - as well as a number of systems that have been described over the past century., (© 2017 Elsevier B.V. All rights reserved.)

Vascular anomalies are a diverse group of pathologic conditions. They have different manifestations, natural histories, and treatments. Compared with other vascular malformations, arteriovenous malformations (AVMs) are considered the most symptomatic and difficult to manage. AVMs inherently progress and have a high rate of recurrence after treatment. Imaging helps provide an accurate and early diagnosis, which can then be used to direct appropriate management, with embolization evolving as the primary therapy. Thus, radiology plays a crucial role in the detection, workup, and management of AVMs. Ultrasonography (US) is a useful initial imaging modality, particularly when AVMs involve the extremities or a superficial or accessible location. Limitations include poor identification of soft-tissue and bone components, as well as suboptimal evaluation of deep or complex AVMs. Magnetic resonance (MR) angiography is the preferred imaging modality for AVMs and should be considered in any symptomatic patient or in the initial evaluation of vascular anomalies that are equivocal at US. Computed tomographic angiography should be reserved for those patients who are unable to undergo MR angiography or for evaluation of acute symptoms, such as bleeding or airway compromise. Conventional catheter-based angiography is useful for real-time depiction and evaluation of AVMs, particularly in the planning and execution of endovascular treatment and in the diagnosis of an AVM when findings from noninvasive imaging are equivocal for a high-flow component. As with the diagnostic workup, MR angiography is the preferred posttreatment modality. (©)RSNA, 2016.

Arteriovenous malformations are the most unpredictable and dangerous congenital malformations. They consist of multiple arteriovenous shunts with high flow and can progress to heart failure. They are rarely localized in the upper limb and pose therapeutic problems. We report a new case in a 27-year old woman, admitted for pulsatile pain in the left elbow. The diagnosis was made by clinical examination and ultrasonography. The surgical treatment without embolization and sclerotherapy, consisted of a large resection of the nidus without postoperative complication., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Clinical history, physical examination, evolution and imaging findings (Colour Doppler sonography, MRI if available) are of pivotal importance in the diagnostic pathway of an infantile vascular anomaly. Histopathology with specific stains and markers is contributive in difficult cases. Differentiation between vascular tumors (hemangioma) and vascular malformations is now well known and integrated into the ISSVA classification. We report here a 6-months-old boy, who presented with a localized cutaneous and expansive vascular birthmark in the left cheek and developed bleedings at the age of 18 months. Diagnostic features of a hemangioma were not evident, and the final diagnosis of a venous malformation was confirmed by histopathology., (© Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: To describe the authors' experience with orbital vascular malformations using the International Society for the Study of Vascular Anomalies (ISSVA) classification and the preferred radiologic techniques., Methods: Review of clinical and radiologic experience from 1976 to 2012. This article presents the findings from several studies conducted on vascular malformations of the orbit, all of which received institutional review board approval when needed., Results: The orbital vascular malformations can be evaluated, classified, and managed according to the ISSVA classification to provide a common language of communication between specialties, which takes into account flow dynamics., Conclusions: The ISSVA can be applied for vascular malformations of the orbit.

Spinal arteriovenous malformations (sAVMs) are rare vascular lesions whose natural history remains incompletely defined. Several classification schemes for sAVMs have evolved based on an improved understanding of the anatomic characteristics as well as pathophysiologic behavior of these arteriovenous shunts. Advances in endovascular technology have inspired the adoption of interventional techniques both as stand-alone treatment and as part of a multi-modality management paradigm for sAVMs. Further refinements in liquid embolic agents as well as improved microcatheter navigability will contribute to an ever-expanding role for endovascular intervention in the management of these lesions.

Objective: The purpose of this study was to review the medical literature and the current classification of vascular anomalies to clarify common misconceptions and provide guidance for imaging and treatment. In this first article of a two-part series, we focus on the fast-flow vascular anomalies., Conclusion: Nonuniformity of terminology across the medical literature hampers understanding of the vascular anomalies. A familiarity with the classification and biology on which this terminology is based is essential for accurate and precise diagnosis.

Objective: The purpose of this article is to review the medical literature and the current classification of the vascular anomalies to clarify common misconceptions and provide guidance for imaging and treatment. In this second article of a two-part series, we focus on slow-flow vascular anomalies., Conclusion: Nonuniformity of terminology across the medical literature hampers understanding of vascular anomalies. A familiarity with the classification and biology on which it is based are essential for accurate and precise diagnosis.

Arterio-venous malformations (AVMs) are congenital vascular malformations (CVMs) that result from birth defects involving the vessels of both arterial and venous origins, resulting in direct communications between the different size vessels or a meshwork of primitive reticular networks of dysplastic minute vessels which have failed to mature to become 'capillary' vessels termed "nidus". These lesions are defined by shunting of high velocity, low resistance flow from the arterial vasculature into the venous system in a variety of fistulous conditions. A systematic classification system developed by various groups of experts (Hamburg classification, ISSVA classification, Schobinger classification, angiographic classification of AVMs,) has resulted in a better understanding of the biology and natural history of these lesions and improved management of CVMs and AVMs. The Hamburg classification, based on the embryological differentiation between extratruncular and truncular type of lesions, allows the determination of the potential of progression and recurrence of these lesions. The majority of all AVMs are extra-truncular lesions with persistent proliferative potential, whereas truncular AVM lesions are exceedingly rare. Regardless of the type, AV shunting may ultimately result in significant anatomical, pathophysiological and hemodynamic consequences. Therefore, despite their relative rarity (10-20% of all CVMs), AVMs remain the most challenging and potentially limb or life-threatening form of vascular anomalies. The initial diagnosis and assessment may be facilitated by non- to minimally invasive investigations such as duplex ultrasound, magnetic resonance imaging (MRI), MR angiography (MRA), computerized tomography (CT) and CT angiography (CTA). Arteriography remains the diagnostic gold standard, and is required for planning subsequent treatment. A multidisciplinary team approach should be utilized to integrate surgical and non-surgical interventions for optimum care. Currently available treatments are associated with significant risk of complications and morbidity. However, an early aggressive approach to elimiate the nidus (if present) may be undertaken if the benefits exceed the risks. Trans-arterial coil embolization or ligation of feeding arteries where the nidus is left intact, are incorrect approaches and may result in proliferation of the lesion. Furthermore, such procedures would prevent future endovascular access to the lesions via the arterial route. Surgically inaccessible, infiltrating, extra-truncular AVMs can be treated with endovascular therapy as an independent modality. Among various embolo-sclerotherapy agents, ethanol sclerotherapy produces the best long term outcomes with minimum recurrence. However, this procedure requires extensive training and sufficient experience to minimize complications and associated morbidity. For the surgically accessible lesions, surgical resection may be the treatment of choice with a chance of optimal control. Preoperative sclerotherapy or embolization may supplement the subsequent surgical excision by reducing the morbidity (e.g. operative bleeding) and defining the lesion borders. Such a combined approach may provide an excellent potential for a curative result. Conclusion. AVMs are high flow congenital vascular malformations that may occur in any part of the body. The clinical presentation depends on the extent and size of the lesion and can range from an asymptomatic birthmark to congestive heart failure. Detailed investigations including duplex ultrasound, MRI/MRA and CT/CTA are required to develop an appropriate treatment plan. Appropriate management is best achieved via a multi-disciplinary approach and interventions should be undertaken by appropriately trained physicians.

Background: Anatomic diversity among cerebellar arteriovenous malformations (AVMs) calls for a classification that is intuitive and surgically informative. Selection tools like the Spetzler-Martin grading system are designed to work best with cerebral AVMs but have shortcomings with cerebellar AVMs., Objective: To define subtypes of cerebellar AVMs that clarify anatomy and surgical management, to determine results according to subtypes, and to compare predictive accuracies of the Spetzler-Martin and supplementary systems., Methods: From a consecutive surgical series of 500 patients, 60 had cerebellar AVMs, 39 had brainstem AVMs and were excluded, and 401 had cerebral AVMs., Results: Cerebellar AVM subtypes were as follows: 18 vermian, 13 suboccipital, 12 tentorial, 12 petrosal, and 5 tonsillar. Patients with tonsillar and tentorial AVMs fared best. Cerebellar AVMs presented with hemorrhage more than cerebral AVMs (P < .001). Cerebellar AVMs were more likely to drain deep (P = .04) and less likely to be eloquent (P < .001). The predictive accuracy of the supplementary grade was better than that of the Spetzler-Martin grade with cerebellar AVMs (areas under the receiver-operating characteristic curve, 0.74 and 0.59, respectively). The predictive accuracy of the supplementary system was consistent for cerebral and cerebellar AVMs, whereas that of the Spetzler-Martin system was greater with cerebral AVMs., Conclusion: Patients with cerebellar AVMs present with hemorrhage more often than patients with cerebral AVMs, justifying an aggressive treatment posture. The supplementary system is better than the Spetzler-Martin system at predicting outcomes after cerebellar AVM resection. Key components of the Spetzler-Martin system such as venous drainage and eloquence are distorted by cerebellar anatomy in ways that components of the supplementary system are not.

Introduction and Aims: Sclerotherapy has become first line treatment for most venous malformations and some lymphatic malformations. We aimed to measure our sclerotherapy treatment success using 3% sodium tetradecyl sulphate (STD) and describe our experience., Materials and Methods: Retrospective five year review (Jan 04-09) of children with vascular malformations treated at our centre with 3% STD. Patients were classified using the Birmingham classification and treatment success was measured through case note review and pre- and post-treatment photographs. FINDINGS AND RESULTS: Forty-three (84.3%) of the 51 patients with vascular malformations (VM) who underwent sclerotherapy derived a benefit. Twelve patients (23.5%) had an excellent result, 31 (60.8%) were improved whilst eight (15.7%) were unchanged. Using Fisher's exact test, there was a statistically significant difference in achieving complete resolution of superficial VMs compared to lesions involving the deeper layers of the head and neck. 17.6% of patients developed a complication with an overall complication rate of 12.2% per injection. There was one major complication with the remainder consisting of superficial skin necrosis that resolved conservatively., Conclusions: Treatment with 3% STD sclerotherapy is effective in venous and some lymphatic vascular malformations. It should be considered an important treatment modality within a multi-disciplinary setting in these difficult problems., (Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

The understanding of hereditary vascular anomalies was hampered for a long time by unclear und unspecific terminology. Today, the classification of the International Society for the Study of Vascular Anomalies (ISSVA) differentiates between vascular tumours (mostly infantile haemangioma) with active endothelial proliferation and regression and vascular malformations (VM), which are defects of the vascular morphogenesis and are distinguished in predominantly venous, arterial, capillary, lymphatic, arteriovenous or combined VM. Symptoms are pain, swelling and restricted movement, accompanied by skin signs like dys-plastic veins and capillary VM (naevus flammeus). Thrombophlebitis and chronic venous insufficiency are related to venous VM. Arteriovenous VM are progressive and can cause ischaemic necroses, in rare cases even a high-output cardiac fail-ure. Lymphatic VM lead to localised swelling, in the long run often to recurrent erysipelas and lymphorroea. Primary imaging is provided by -ul-trasound including flow measurements. Mor-phol-ogy and organ involvement is best delineated by magnetic resonance imaging. Phlebography is used to image deep venous system anomalies and is always accompanied by varicography of the dysplastic parts of the venous VM. Digital subtraction angiography is performed to demon-strate the flow pattern in feeding arteries, the nidus and the drainage veins of arteriovenous VM. Besides size and localisation the prognosis of the patients is determined by the pressure (the high-er the pressure, the poorer the prognosis) and the flow rate (the higher the flow rate, the poorer the prognosis) in the VM. Diagnosis and treatment of these rare diseases are best performed in special-ised, interdisciplinary centres., (© Georg Thieme Verlag KG Stuttgart ˙ New York.)

The process of understanding and treating children with vascular anomalies has been hampered by confusing and occasionally incorrect terminology. The most important step when evaluating a maxillofacial vascular anomaly is to determine whether it is a tumor or a malformation. In most cases, this diagnosis can be made by history and physical examination. Selective radiographic imaging is helpful in differentiating vascular malformations or the extent of bony involvement and/or destruction. Children with vascular anomalies should be managed by an interdisciplinary team of trained providers who are committed to following, treating, and studying patients with these complex problems., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Superficial venous malformations are part of a larger group now called superficial vascular anomalies and previously known as angiomas. These include vascular tumors or infantile hemangioma, low-flow vascular malformations (capillary, lymphatic, and superficial venous malformations) and high-flow vascular malformations (arteriovenous malformations). Some of these lesions are complex. This classification facilitates their multidisciplinary therapeutic management. Embolization is an effective curative treatment for malformations of small and intermediate size. The objective for large or complex malformations is to restore anatomic function and improve cosmetic results., ((c) 2010. Published by Elsevier Masson SAS.)

Objective: The aim of the study was to evaluate the incidence of postirradiation imaging changes after stereotactic radiosurgery for arteriovenous malformations (AVM) and cerebral cavernous malformations (CCM)., Material and Methods: A group of 85 patients treated for arteriovenous malformations (62 patients, 73%) and cavernomas (23 patients, 27%) between October 2001 and December 2005 was analyzed. All patients were treated with stereotactic radiosurgery with doses ranging from 8-28 Gy. After the irradiation, magnetic resonance imaging (MRI) or computed tomography (CT) was performed at 6 to 12-month intervals to assess the effects of the treatment. The mean follow-up time for the whole group was 27.3 months; AVM group -- 26 months; CCM group -- 30.9 months. All the imaging data were carefully reviewed to identify the radiological symptoms of postradiosurgical damage. T2 or FLAIR hyperintensity, T1-hypointensity and contrast enhancement on MRI and the presence of hypodense areas and contrast enhancement on CT examinations were assessed., Results: Imaging abnormalities were found in 28 (33%) patients. The symptoms of postradiosurgical damage were observed in 21 (33.9%) patients in the AVM group and 7 (30.4%) patients in the CCM group. Radiological symptoms of radiation necrosis associated with neurological deterioration were identified in two patients with cavernomas, while no radiation necrosis was found in the AVM group. Patients in whom radiological signs of focal brain edema or gliosis existed were asymptomatic., Conclusions: Radiological symptoms of postradiosurgical damage affected about one third of the irradiated patients, typically without any clinical manifestations. Patients irradiated for CCMs seem to be more prone to develop symptomatic postradiosurgical necrosis; this observation, however, requires further investigation.

The differential diagnosis of vascular malformations of the upper aero-digestive tract may represent a diagnostic challenge and become a hindrance for therapy planning. The terminus "extracranial vascular anomalies" of the Head and Neck integrates hemangiomas and vascular malformations. The differential diagnosis contains benign and malign neoplasms, naevi, pigmentations and purpura., (Georg Thieme Verlag KG Stuttgart New York.)

We report on a case of a 12-year-old girl that was admitted under our care complaining of headache for over a month which was accompanied by vomiting and diplopia over the last 10 days. On neurological examination a right upper limb tremor and cervical rigidity were noted. CT and MRI scan was performed and revealed a giant left frontotemporal lesion. The lesion was heterogenous with calcifications and hemosidirin, surrounded by brain swelling and causing midline shift. There was little enhancement after gadolinium administration. The last finding led us to consider the presence of a vascular abnormality as a possible diagnosis. The patient was operated upon via a left fronto-temporal craniotomy. We managed to excise the lesion totally. Histopathology revealed the presence of an AVM. Postoperatively the patient was neurologically intact but a subcutaneous collection of CSF was noted that was successfully treated by drainage. Although surgical treatment of deeply seated giant AVM's in the dominant hemisphere of speech and motor-sensory area have a relative high proportion of postoperative neurological deficit, careful surgical intervention can produce excellent outcome.

During treatment of spinal arteriovenous malformations (AVMs), such as dural arteriovenous fistula (AVF), perimedullary AVF, and intramedullary AVM, it is often difficult to identify the feeding artery and draining vein because of presence of multiple dilated veins in the dural space and multiple shunts. Disruption of incorrect vessels may elicit major functional deficits in the spinal cord. To avoid such complications, it is extremely important to identify the correct vessels prior to and during surgical treatment. Recently, several types of techniques have been developed for diagnosis and treatment of spinal AVMs. Although spinal AVMs must be diagnosed by digital subtraction angiography (DSA) before any surgical treatment can begin, other techniques such as CT angiography and contrasted MR angiography are valuable as a form of screening and can be useful in guiding the DSA procedure. In addition, several techniques including intraoperative angiography, dye-injection and the micro Doppler method have proven useful during the surgical procedure for understanding complex spinal vascular architectures. These approaches facilitate in the identification of feeding vessels, thereby preventing neurological deterioration due to disruption of the incorrect vessels during the surgery of spinal AVF. At the neurophysiological level, intraoperative MEP monitoring is a sensitive method for the detection of immediate motor fiber damage. Utilization of these innovative approaches will contribute to the safe and effective treatment of spinal AVMs.

Orbital vascular lesions, mainly including hemangioma and vascular malformation, are the most common disorders among orbital diseases. Vascular lesions of the orbit have clinically complicated presentations and are very hard to deal with. Selection of therapeutic modality on orbital vascular lesions requires an appropriate classification of them. An improved classification of these lesions has been proposed by the Orbital Society based on the pathological types and hemodynamic features and has been extensively used in developed countries. However, orbital vascular lesions are still being classified based on morphology in China. This classification system does not represent the pathological difference between hemangioma and vascular malformation of the orbit, nor the hemodynamic characteristics among different vascular malformations of the orbit. Morphology based classification has hampered scientific dialogue and confused clinicians, with occasionally serious consequences for patients. Thus, the use of a pathology and hemodynamics based classification of orbital vascular lesions should be highly advocated. We can expect that the use of appropriate classification can improve the management of these lesions in our country.

Pediatric hematologist/oncologists have a critical role in the diagnosis and management of patients who have complex vascular anomalies. They provide the clinical and medical skills needed to diagnose, treat, and manage these patients. Hematologist/oncologists also provide support for clinical trials and drug development to further treatment options for these patients.

Arteriovenous malformation (AVM) of the tongue is a rare lesion of the cranio-facial vascular anomaly. Decision making concerning the vascular anomaly is not established because there are complex classifications of diagnosis and many treatment options. We report a case of AVM of the tongue, and review vascular anatomy and knowledge for treating this lesion. A 50-year-old man presented with dysarthria, sleep apnea and snoring because of a mass lesion of his sublingual region that had become larger over a two-year period. Neuroradiological examination revealed lingual arteriovenous fistula (AVF) associated with AVM of the tongue base. We performed transfemoral transarterial embolization via both lingual arteries using Polyvinyl alcohol particles and Eudragit-E as non-adhesive glue material. Final angiograms after embolization revealed a small residual nidus fed by the right facial artery mental branch, but shunt flow was markedly reduced. This vascular malformation was removed after a day of TAE (transarterial embolization). The patients symptom was improved and relapse has not been confirmed though 18 months have passed since the surgery. Using classification proposed by Mulliken and Glowacki, vascular anomalies are divided into two groups: hemangiomas and vascular malformations (AVM/F, arterial, venous, capillary, lymphatic and combined). AVM/F is classified into high flow malformation. TAE is useful for high flow malformation and can be used as the sole treatment or as an adjunct. Treatment should be to eradicate nidus or fistula completely, which is the fundamental abnormality because even the smallest residual nidus will expand to cause recurrence. The treatment of Cranio-facial AVM's requires rigorous differential diagnosis and appropriate management. Inadequate treatment is thought to contribute to collateral flow and disease progression in advanced AVM, making further management difficult.

Vascular anomalies are an uncommon cause of gastrointestinal bleeding. Imaging plays an important role in the diagnosis and therapy of these anomalies. Accurate diagnosis, classification and awareness of associated syndromes are mandatory for applying the appropriate management. In this pictorial essay we review the classification, imaging characteristics and treatment of gastrointestinal vascular anomalies.

Vascular anomalies are a complex pathological group. They are especially difficult to study because of confusion in the terminology used. The classification developed by the ISSVA (International Society for the Study of Vascular Anomalies) now allows using a common scientific language. The classification is based on clinical, radiological, hemodynamic, and histological arguments. There are two groups of lesions: vascular tumors and vascular malformations. Vascular tumors are associated to vascular proliferation. They are called hemangioma and can be infantile or congenital. Vascular malformations are associated to vessels with morphologic anomalies. They are classified according to the distorted vessel type, capillary, venous, lymphatic, and arteriovenous). Such a classification has many implications. It is a guide for the orientation of radiological exams and treatment of vascular anomalies. The management of these anomalies is still difficult and must involve an interdisciplinary approach.

We present a rare case of maxillary intraosseous vascular malformation and review the nomenclature used by pathologists and clinicians in classifying vascular anomalies. We also discuss the literature and highlight potential management pitfalls.

Vascular malformations are anomalies always present at birth that, contrary to hemangiomas, never regress and may grow during lifetime. Clinical presentation of vascular malformations is extremely variable and ranges from asymptomatic spots of mere aesthetic concern to lesions with high blood flow or located in critical sites that may be life-threatening. Given the low incidence of these disorders it is difficult to establish therapeutic guidelines. In addition to a correct classification of vascular anomalies, it is necessary a multidisciplinary approach for the follow-up and management of these patients. The first part of this review focuses on the different classifications of vascular anomalies, maintaining as reference the one proposed by the International Society for the Study of Vascular Anomalies (ISSVA). Additionally, clinical features of the different subtypes of vascular anomalies as well as their association in certain syndromes are reviewed.

Objectives: To examine our vascular anomalies team's experience with tongue arteriovenous malformations (AVM) with specific emphasis on the spectrum on disease and surgical management., Methods: Retrospective chart review of 11 patients (10 female, 1 male), discovered from 1997 to 2005 with histological, radiographic, and clinical characteristics consistent with tongue AVM., Results: Four patients displayed advanced disease with malformations involving the tongue, floor of mouth, and neck. Contributions from multiple feeding arteries were identified by angiography as each patient reported a prior history of surgical or embolic procedures. These lesions required preoperative embolization and extensive resection with complex reconstruction (mean operating time, 10.9 hr). One patient had evidence of recurrent disease (mean follow-up, 24.6 mo). In contrast, seven patients presented with discreet tongue malformations with a single feeding lingual artery. These patients reported no prior intervention, required only one resection (mean operating time, 2.8 hr), and have shown no evidence of recurrence (mean follow-up, 11 mo). Slight histologic differences between advanced versus focal tongue AVM were identified., Conclusions: This study suggests that tongue AVM can occur within a spectrum of disease with different clinical presentations, radiographic findings, and histology among patients with focal versus advanced lesions. Inadequate treatment is thought to contribute to collateral flow and disease progression in advanced AVM, making further management difficult. However, focal tongue AVM may represent early lesions that are more amenable to surgical management.