How I do it. Arteriovenous malformation management

Single-cell and spatial transcriptomic analyses reveal transcriptional cell lineage heterogeneity in extracranial arteriovenous malformation

BACKGROUND

Extracranial arteriovenous malformations (eAVMs) are rare congenital vascular anomalies consisting of abnormal artery-vein bypass with no intervening capillary network, and can lead to disability and death. The critical genetic determination factors and key transcriptional pathways of the eAVMs genesis process are still unclear.

OBJECTIVE

To generate an overview of the molecular information within eAVMs at the single-cell level.

METHODS

We performed single-cell RNA sequencing (scRNA-seq) on nine samples of eAVMs receiving a confirmatory histopathologic evaluation from a board-certified dermatopathologist and two nonlesional tissue sample controls. 10x Visium spatial transcriptomics (ST) was performed on one eAVM to spatially localize heterogeneous cells and profile the gene expression dynamics of the cells in their morphological context. The scRNA-seq and ST data were integrated and analyzed to further query for spatially restricted mapping of intrapopulation heterogeneous cells.

RESULTS

We identified different cell states of endothelial cells (ECs), perivascular cells and immune cells in eAVMs, uncovered the presence of MAFB+ nidus ECs, characterized mesenchymal activation in ECs, and identified transcriptional variation within perivascular cells and the presence of smooth muscle-like pericytes in eAVMs. Dysregulated cell to cell interactions among ECs, perivascular cells and immune cells that are associated with eAVMs, including those involving MDK, VEGF, ANGPT, SEMA3 and GALECTIN-9 were cataloged. Together, our results depicted the heterogeneity underlying cell function and interaction of eAVMs at a single-cell resolution.

CONCLUSION

We present a comprehensive picture of the cell-resolution atlas that describes the transcriptomic heterogeneity underlying cell function and interaction in eAVMs.

Retrospective clinical study on the efficacy and complications of interventional embolization in the treatment of scalp arteriovenous fistula

Introduction

Scalp arteriovenous fistula (AVF) is a rare and intricate vascular anomaly characterized by a direct connection between an artery and a vein, without an intervening capillary system. This anomaly can induce significant local hemodynamic changes and is associated with various complications, such as pain, a pulsatile mass, increasing swelling, and venous hypertension skin ulcerations which may be non-healing. This study aimed to evaluate the efficacy and safety of interventional embolization treatments for scalp AVF at Shandong Provincial Hospital.

Methods

This retrospective clinical analysis assessed 21 patients who underwent interventional embolization between 2018 and 2024. Patients included were those treated in the vascular surgery department at Shandong Provincial Hospital, who had comprehensive medical records and follow-up data. Treatment methods, outcomes, and complications were thoroughly analyzed through patient medical records.

Results

Among the patients studied, direct puncture was the most prevalent treatment method, employed in 42.86% (9/21) of cases, followed by various combinations of arterial, venous, and direct approaches. Ethanol, used in 85.71% (18/21) of the cases, demonstrated its broad efficacy and application in clinical settings. Immediate imaging post-treatment confirmed a cure rate of 85.71% (18/21). The main postoperative complications included swelling, with some patients also experiencing nodules, scabbing, or hair loss.

Conclusion

Interventional embolization has proven to be a safe and effective method for managing scalp AVF, significantly minimizing complications. Future research should focus on further optimizing these treatment methods to enhance efficacy and improve patient quality of life.

SOLAMEN syndrome with cardiovascular damage

SOLAMEN syndrome is a rare, recently recognized congenital syndrome that is characterized by progressive and hypertrophic diseases involving multiple systems, including segmental overgrowth, lipomatosis, arteriovenous malformation (AVM) and epidermal nevus. According to literatures, SOLAMEN syndrome is caused by heterozygous PTEN mutation. Phenotypic overlap complicates the clinical identification of diseases associated with PTEN heterozygous mutations, making the diagnosis of SOLAMEN more challenging. In addition, SOLAMEN often presents with segmental tissue overgrowth and vascular malformations, increasing the possibility of misdiagnosis as klipple-trenaunay syndrome or Parks-Weber syndrome. Here, we present a case of a child presenting with macrocephaly, patchy lymphatic malformation on the right chest, marked subcutaneous varicosities and capillaries involving the whole body, overgrowth of the left lower limb, a liner epidermal nevus on the middle of the right lower limb, and a large AVM on the right cranial thoracic entrance. Based on the typical phenotypes, the child was diagnosed as SOLAMEN syndrome. detailed clinical, imaging and genetic diagnoses of SOLAMEN syndrome was rendered. Next-generation sequencing (NGS) data revealed that except for a germline PTEN mutation, a PDGFRB variant was also identified. A subsequent echocardiographic examination detected potential cardiac defects. We suggested that given the progressive nature of AVM and the potential severity of cardiac damage, regular echocardiographic evaluation, imaging follow-up and appropriate interventional therapy for AVM are recommended.

The Guidelines for Percutaneous Transhepatic Portal Vein Embolization: English Version

Preoperative portal vein embolization is a beneficial option to reduce the risk of postoperative liver failure by promoting the growth of the future liver remnant. In particular, a percutaneous transhepatic procedure (percutaneous transhepatic portal vein embolization) has been developed as a less-invasive approach. Although percutaneous transhepatic portal vein embolization is widely recognized as a safe procedure, various complications, including rare but fatal adverse events, have been reported. Currently, there are no prospective clinical trials regarding percutaneous transhepatic portal vein embolization procedures and no standard guidelines for the PTPE procedure in Japan. As a result, various methods and various embolic materials are used in each hospital according to each physician's policy. The purpose of these guidelines is to propose appropriate techniques at present and to identify issues that should be addressed in the future for safer and more reliable percutaneous transhepatic portal vein embolization techniques.

Arteriovenous malformation of the ear optimized with cinematic rendering images: A case presentation and review of literature

Arteriovenous malformations (AVMs) define rare aberrations in vascular morphogenesis. AVMs are typically present at birth, and unless they are stimulated to grow quickly by trauma, illness, or hormonal effects, they enlarge in proportion to an individual's growth. Clinical manifestations of AVMs are often linked to abnormal mass effects and blood perfusion. In this report, we describe a unique case of AVM of the left ear in a 24-year-old male, employing cinematic rendering along with a review of differential diagnosis and treatment options.

Embolo/sclerotherapy for the treatment of hand arteriovenous malformations: a single-center retrospective cohort experience

Purpose

To retrospectively report our preliminary experience of treating hand arteriovenous malformations (AVMs) with embolo/sclerotherapy.

Materials and methods

Retrospectively review the demographics, treatment detail, outcome data, and complications of 13 consecutive patients with hand AVMs from January 2018 to December 2021. We embolize the dominant outflow vein with elastic coils and then use absolute ethanol or polidocanol for intravascular sclerotherapy and bleomycin for interstitial sclerotherapy.

Results

Yakes type II presents in four lesions, type IIIa in six, and type IIIb in three. A total of 29 treatment episodes were conducted for the 13 patients (1 episode for 3 patients, 2 for 4 patients, and 3 for 6 patients; the repeated treatment rate was 76.9%). The mean stretched length of coils for 1 treatment episode was 95 cm. The mean absolute ethanol dosage was 6.8 ml (range 4-30 ml). In addition, 10 ml of 3% polidocanol foam was injected and interstitial sclerotherapy with 150,000 IU bleomycin was performed on every patient. The post-operative arterial-dominant outflow vein pressure index (AVI) increased in the 29 procedures (6.55 ± 1.68 vs. 9.38 ± 2.80, P < 0.05). The Mann-Whitney U test showed that the post-operative AVI was higher in patients without re-intervention (P < 0.05). Local swelling occurred after all the procedures. Blistering occurred in 6 of the patients in 13 (44.8%) of the 29 procedures. Superficial skin necrosis occurred in 3 of the patients in 5 (17.2%) of the 29 procedures. The swelling, blistering, and superficial skin necrosis recovered within 4 weeks. No finger amputation occurred. The follow-up time was 6 months. The 6-month assessment of clinical improvement after the last treatment episode showed that 2 patients were cured, 10 were improved, and 1 remained unchanged. With regard to angiographic evaluation, 9 showed partial response and 4 complete response.

Conclusion

Embolo/sclerotherapy can be effective and safe for hand AVM. The AVI increased significantly after embolo/sclerotherapy, and the index may be valuable in predicting recurrence in further study.

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

ABSTRACT

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Management of Pancreatico-duodenal arterio-venous malformation

Purpose

To describe the interventional management and clinical outcome of pancreatico-duodenal arterio-venous malformations (PDAVMs).

Material and Methods

Seven patients presenting a PDAVM (6 women, 1 male; mean age: 61) were retrospectively reviewed. Technical, clinical success and complications of embolization and surgical management of symptomatic PDAVMs were assessed. Technical success was defined as a complete occlusion of the PDAVM and clinical success as no clinical symptom or recurrence during follow-up. Patients with asymptomatic PDAVMs were followed clinically, by Doppler ultrasound and CT-angiography.

Results

Mean follow-up time was 69 months (15-180). Five symptomatic patients presented with upper gastrointestinal bleeding (n=3), ascites (n=1), and abdominal pain (n=1). Two patients were asymptomatic. The PDAVMs were classified as follow: Yakes I (1), IIIa (2), IIIb (3) and IV (1). Five symptomatic patients were treated with 9 embolization sessions with arterial approach (onyx®, glue, coils) in 7 and venous approach in 2 (plugs, coils, covered stents, STS foam and onyx®). Technical success of embolization was 60% (3/5). Devascularization was incomplete for 2 Yakes IIIB patients. Clinical success of embolization was estimated at 80% (4/5) as one patient required additional surgery (Whipple) because of persistent bleeding. One splenic vein thrombosis was treated successfully by mechanical thrombectomy and heparin. No recurrence occurred during follow-up. No progression was documented in asymptomatic patients.

Conclusion

Embolization of symptomatic PDAVMs is effective and surgery should be performed in second intention. Complete devascularization is more difficult to obtain in Yakes III PDAVM.

Recurrent urinary retention due to clots caused by a congenital renal arteriovenous malformation that forms a complex vascular network: Report of two cases

INTRODUCTION

Repeated urinary retention due to clots caused by congenital renal arteriovenous malformation is rare.

CASE PRESENTATION

A 40-year-old woman (case 1) and a 66-year-old man (case 2) experienced recurrent urinary retention due to clots. Neither patient had a history of renal trauma nor was taking any medications. Contrast-enhanced abdominal computed tomography revealed a large hematoma in the renal pelvis and ureter with no masses, stones, or vascular lesions and only dilated blood vessels in the arterial phase in case 1. Angiography of the kidney in both patients revealed an arteriovenous malformation, and embolization of the arteries feeding the arteriovenous malformation was performed. Soon after embolization, hematuria disappeared completely with no recurrence for 5 years in case 1 and 2 years in case 2.

CONCLUSION

Congenital renal arteriovenous malformation should be considered as a cause of recurrent clot retention, and angiographic embolization of the feeding arteries can be an effective treatment.

The Efficiency and Safety of Ethanol Sclerotherapy for Labial Arteriovenous Malformations

BACKGROUND

AND PURPOSE: Labial arteriovenous malformations, usually with accompanying cosmetic defects, pain, and bleeding, are aggressive with characteristics of high risk of recurrence and absence of effective treatment. This study presents a technique of sclerotherapy for labial arteriovenous malformations.

METHODS

Patients with labial arteriovenous malformations were treated with percutaneous ethanol sclerotherapy with or without polyvinyl alcohol particle embolization. The efficiency, complications, and recurrence rate were analyzed with imaging and clinical follow-up data.

RESULTS

Of the 15 patients, all patients received one or more treatment sessions, from which eight realized a cure (53.3%) and five had remission (33.3%). Two patients who did not achieve an effective result await further treatment. Four (26.7%) patients treated with ethanol sclerotherapy combined with polyvinyl alcohol particle embolization developed recurrence. No recurrence occurred in patients treated with only sclerotherapy (mean ± SD follow-up 17.2 ± 8.1 months). Thirteen patients developed transient complications: swelling, mild bleeding, and blistering. One patient had a postoperative scar of about 0.5 cm.

CONCLUSIONS

Ethanol sclerotherapy appears effective as a treatment for labial arteriovenous malformations. Careful application of the treatment can reduce the occurrence of complications.

Incidence of major complications from embolo-sclerotherapy of head and neck vascular malformations in a single specialist centre

OBJECTIVE

Current data on the nature and rate of major complications for embolo-sclerotherapy (EST) of vascular malformations are scarce. However, even fewer studies focus on vascular malformations specific to the head and neck, which confer an increased specific risk of airway compromise, neurologic and ophthalmologic injury. More understanding is required surrounding the type and incidence of complications to improve treatment planning and informed consent. Therefore, this study aimed to review major complications secondary to EST of head and neck vascular malformations over a 5-year period in a single specialized multidisciplinary centre for vascular anomalies.

METHODS

All interventions were decided by the multidisciplinary team. Demographic, procedural and complication data between 1st January 2013 and 31st December 2017 were prospectively documented in a dedicated database and analysed. EST of high-flow vascular malformations (HFVMs) was performed by selective catheter angiography or direct injection, and by direct injection only for low-flow vascular malformations (LFVMs). Major complications were defined as any tissue or functional damage caused by direct injection, distal embolization or tissue reaction and were decided by the multidisciplinary team.

RESULTS

Forty-eight patients (median age of 35 years; range of 14-70 years; 18 men and 30 women) had 100 EST procedures for head and neck vascular malformation. Of these, 14 patients had EST for HFVM and 34 patients for LFVM, total 43 and 57 procedures, respectively. Overall, five patients with HFVM developed major complications from EST when compared with two patients with LFVM (p = 0.0167). Two patients required pre-emptive tracheostomy due to risk of post-operative airway compromise. Overall, seven (14.6%) patients experienced major complication from EST. In the HFVM group, major complications from EST occurred in five patients; four cases of tissue ulceration and necrosis (two needed debridement, one healed with resultant fibrosis that impeded speech and one resolved spontaneously) and one post-procedural airway compromise requiring tracheostomy. Meanwhile, in the LFVM group, major complications occurred in two patients; one case of severe necrosis involving the alar cartilage, lip and cheek requiring debridement and reconstruction under plastics and one simple cellulitis. No patients sustained stroke or vision impairment.

CONCLUSIONS

EST is relatively safe for head and neck vascular malformations in a high-volume experienced centre. Our major complication rate of 14.6% per patient (35.7% for HFVM; 5.9% for LFVM) or 7% per procedure (11.6% for HFVM; 3.5% LFVM) compares favourably with published data from other centres. These data will improve treatment planning and informed consent for EST for both HFVM and LFVM of the head and neck.

Giant parapharyngeal high-flow arteriovenous malformation causing airway compromise: emergency embolo-sclerotherapy via an endovascular-only approach

Head and neck arteriovenous malformations are the commonest extracranial vascular malformations but demonstrate a unique challenge in the limited available surgical options secondary to their intimate association to vital structures. We present a case of middle-aged female patient who presented with threatened upper-airway obstruction and bleeding secondary to a slowly enlarging parapharyngeal arteriovenous malformations. She was treated with an endovascular-only approach with the proximal arteriole branches selectively undergoing embolo-sclerotherapy with an optimal radiological and clinical outcome. We also demonstrate the utility of elective tracheostomy prior to intervention.

How to Treat Peripheral Arteriovenous Malformations

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.

Therapeutic outcomes of embolotherapy of extremity bone intraosseous arteriovenous malformation with ethanol, coils, and n-butyl cyanoacrylate

OBJECTIVE

We evaluated the therapeutic outcomes of embolotherapy for bone arteriovenous malformations (AVMs) affecting the extremities using ethanol, coils, and n-butyl cyanoacrylate (NBCA).

METHODS

We reviewed the data from 36 patients (18 males, 18 females; mean age 25 years; age range, 1-64 years) with bone AVMs affecting their extremities who had undergone embolotherapy using ethanol, coils, and NBCA from December 1996 to July 2019. Of the 36 patients, 19 had had pure bone AVMs and 17 mixed bone and soft tissue (MBS) AVMs. Embolotherapy was performed using direct puncture or a transvenous or an intra-arterial approach (range, 1-18 procedures; mean, 5 procedures). During the 178 embolotherapy procedures, ethanol was used in all 36 patients, except for 1. Coils were used in 14 patients, and NBCA and a lipiodol mixture in 9 patients. The therapeutic outcomes were evaluated by the clinical symptom response and the degree of devascularization on follow-up angiography or computed tomography. The major and minor complications were also evaluated.

RESULTS

The clinical success (cure or markedly improvement) rate of embolotherapy for pure bone AVMs was significantly better than that for the MBS AVMs (88% vs 18%; P < .001). The complete devascularization rate of the bone AVM component of the MBS AVMs was 71%; however, the cure rate of the MBS AVMs was 0% owing to the remaining soft tissue AVMs. Of the 36 patients, 12 experienced complications, including 11 minor (2 skin bullae formation and 10 transient peripheral nerve injury) and 1 major (longstanding nerve palsy).

CONCLUSIONS

Embolotherapy for bone AVMs affecting the extremities using ethanol, coils, and an NBCA mixture is effective and safe for the resolution or improvement of symptoms, especially in those with pure bone AVMs.

3T MRI of Peripheral Vascular Malformations: Characteristics and Comparison of Two Fat-Saturated sequences: Short Tau Inversion Recovery Versus Three-Dimensional High-Resolution Volume Interpolated Gradient Recalled Echo

PURPOSE

 To assess morphological and hemodynamic characteristics of peripheral vascular malformations on 3 T magnetic resonance imaging (MRI) including qualitative comparison of two fat-saturated sequences: short tau inversion recovery (STIR) and three-dimensional high-resolution volume interpolated gradient recalled echo (GRE).

MATERIALS AND METHODS

 During 9 months, 100 patients with suspected or known vascular malformations were prospectively assessed on a 3 T scanner using T2-weighted STIR and turbo spin echo (TSE), T1-weighted TSE, time-resolved contrast-enhanced magnetic resonance angiography (MRA) with interleaved stochastic trajectories (TWIST) and T1-weighted volume interpolated breath-hold examination (VIBE) after contrast enhancement. The analysis included signal behavior and morphologic and hemodynamic characteristics. Additionally, the image quality of the fat-saturated sequences was evaluated by 2 radiologists.

RESULTS

 86 patients (14 dropouts; 57 female, 29 male; mean age 26.8 years, age range 1-56) were analyzed. 22 had high-flow and 64 low-flow malformations, including 14 with a lymphatic component. In 21 of 22 patients with high-flow malformations, typical characteristics (flow voids, hyperdynamic arteriovenous fistula, dilated main/feeder-arteries and draining veins) were documented. Patients with low-flow malformations had phleboliths in 35 cases, fluid-fluid levels in 47 and dilated draining veins in 23. Lymphatic malformations showed peripheral contrast enhancement of cyst walls in the volume interpolated GRE. The comparison of fat-saturated sequences showed significantly better results of the volume interpolated GRE in all categories except the presence of artifacts which were significantly reduced in the STIR (p < 0.05).

CONCLUSION

 3 T MRI with MRA provides detailed morphological and hemodynamic information of different types of peripheral vascular malformations. Contrast-enhanced high-resolution volume interpolated GRE proved superior to STIR in differentiating morphologic features and to be diagnostic in the differentiation of lymphatic parts and joint involvement.

KEY POINTS

  · 3 T MRI with MRA offers detailed information about vascular malformations.. · Fat-saturated MRI provides especially information about morphological characteristics, extent and tissue involvement.. · Volume interpolated GRE proved superior in almost all categories compared to STIR.. · Volume interpolated GRE showed more artifacts.. · Volume interpolated GRE additionally allows differentiation of lymphatic parts and evaluation of joint involvement..

CITATION FORMAT

· Höhn F, Hammer S, Fellner C et al. 3T MRI of Peripheral Vascular Malformations: Characteristics and Comparison of Two Fat-Saturated sequences: Short Tau Inversion Recovery Versus Three-Dimensional High-Resolution Volume Interpolated Gradient Recalled Echo. Fortschr Röntgenstr 2021; 193: 446 - 458.

Treatment Outcomes of Embolization for Peripheral Arteriovenous Malformations

PURPOSE

To evaluate treatment outcomes of embolization for peripheral arteriovenous malformations (AVMs) in a tertiary referral center where ethanol is the primary agent of choice.

METHODS

A retrospective study was performed of 93 patients (median age, 31 years; range, 2-66 years) with peripheral AVMs treated with embolization (n = 442; median, 2 per patient; range, 1-82) between January 2010 and July 2016. Ethanol was used in most cases (n = 428; 97%). AVMs were classified as type I (n = 3), type II (n = 57), type IIIa (n = 5), type IIIb (n = 15), and type IV (n = 13) according to the Yakes classification system. Effectiveness of embolization was based on AVM devascularization on angiography: 100% (total), 90%-99% (near-total), 70%-90% (substantial), 30%-70% (partial), and 0%-30% (failure). Complications were graded according to the Society of Interventional Radiology classification.

RESULTS

In 69% of patients, 70%-100% devascularization was achieved. Total and near-total occlusion of the nidus were more often achieved in AVMs of types I and IIIa (both 100%) than in AVMs of types II, IIIb, and IV (56%, 67%, and 39%, respectively; P = .019). A total of 109 complications were identified: 101 minor (22.9%) and 8 major (1.8%). Major complications included wounds (n = 5), false aneurysm (n = 1), finger contracture (n = 1), and severe pain (n = 1) requiring therapy. The patient complication risk was significantly affected by the number of procedures (relative risk = 2.0; P < .001). Age, AVM location, and angioarchitecture type did not significantly affect complication risk.

CONCLUSIONS

AVM embolization resulted in 70%-100% devascularization in 69% of patients, with few major complications. This study indicates that the type of AVM angioarchitecture affects the number of procedures needed and the achievability of AVM devascularization.

Monitoring Arteriovenous Malformation Response to Genotype-Targeted Therapy

Arteriovenous malformations (AVMs) have recently been reported to have a high incidence of somatic KRAS mutations suggesting potential for treatment with mitogen-activated protein kinase inhibitors. In this case report, we describe genotype-targeted treatment of a KRAS mutant metameric AVM in a patient with Cobb syndrome using the mitogen-activated protein kinase inhibitor trametinib. Therapeutic response was monitored with phase-contrast magnetic resonance angiography to quantify AVM arterial inflow as an imaging biomarker. Treatment with trametinib resulted in a substantial decrease in blood flow to the AVM, with a >75% reduction in arterial inflow after 6 months of trametinib therapy.

Clinical and imaging features of intraosseous arteriovenous malformations in jaws: a 15-year experience of single centre

Intraosseous arteriovenous malformations in jaws (j-AVMs) are rare congenital high-flow vascular anomalies with a high tendency of life-threatening haemorrhage and are regarded as one of the most dangerous haemorrhagic diseases in maxillofacial region. Pre-treatment clinical and imaging evaluations serve as the most important diagnostic modalities. A retrospective study involved 211 patients with j-AVMs from November 2003 to November 2017 was performed. The male-to-female ratio of j-AVMs was approximately 4:3. The mean age of the patients with j-AVMs is 21.86. Bleeding was the main complaint associated with j-AVMs. J-AVMs occurred in the mandible more often than in the maxilla (64.93% and 32.23%, respectively). Most j-AVMs (95.26%) occurred in the posterior teeth region. Classical imaging features of j-AVMs included: an unclear maxillary sinus with a mild ground-glass appearance (maxillary j-AVMs) and a clear oval or irregular lucency that is mostly centred on the root of the first molar (mandibular j-AVMs) on OPGs, enhancement in the cancellous bone on contrast-enhanced CTs. Other atypical features of j-AVMs were also concluded. A comprehensive diagnose system based on clinical and imaging features of j-AVMs could provide valuable reference data for clinical management of j-AVMs and help avoid improper iatrogenic trauma or delayed treatment.

Incidence of major complication following embolo-sclerotherapy for upper and lower extremity vascular malformations

OBJECTIVE

The current literature on the major complications of embolo-sclerotherapy of upper and lower extremity vascular malformations is scarce. Evaluating and understanding the rates and types of potential major complications of embolo-sclerotherapy of vascular malformations help treatment planning and informed consent. Therefore, this study reviewed major complications following embolo-sclerotherapy of all upper and lower extremity vascular malformations in a single specialized multidisciplinary vascular malformation center over a 5-year period.

METHODS

All patients with vascular malformations underwent multidisciplinary directed intervention. Demographic, procedural, follow-up, and complication data were collected prospectively in a dedicated database, and reviewed retrospectively. Major complications for upper and lower extremity vascular malformations from 1 January 2013 to 31 December 2017 were analyzed. All embolo-sclerotherapies of high-flow vascular malformations (HFVMs) were performed under selective catheter angiography and direct injection, but low-flow vascular malformations (LFVM) with direct injection only. Major complications were defined as any tissue or functional damage caused by direct injection, distal embolization, or tissue reaction.

RESULTS

Seventy patients (median age of 25 years; 44 males and 26 females) had 150 embolo-sclerotherapy procedures for upper extremity vascular malformation. Of these, 28 patients had embolo-sclerotherapy for HFVM and 42 patients for LFVM; total 78 and 72 procedures, respectively. A total of 107 patients (median age of 26 years; 42 males and 65 females) had 160 embolo-sclerotherapy interventions for lower extremity vascular malformations. Of these, 18 patients had embolo-sclerotherapy for HFVM and 89 patients for LFVM; total of 30 and 130 procedures, respectively. The overall major complication rates following embolo-sclerotherapy of upper and lower extremity vascular malformations were 14.3% and 4.7%, respectively (P = 0.030). In the upper extremity HFVM group, major complications from embolo-sclerotherapy occurred in five patients; three ischemic fingers requiring amputation and two skin ulcerations. Meanwhile, in the upper extremity LFVM group, major complications occurred in five patients; one median nerve injury requiring nerve grafting and hand therapy, one hand contracture requiring tendon release, and three skin ulcerations. There was only one major complication, which was cellulitis in the lower extremity HFVM group. In the lower extremity LFVM group, major complications occurred in four patients; two skin ulcerations, one cellulitis, and one deep vein thrombosis.

CONCLUSIONS

Embolo-sclerotherapy is relatively safe for upper and lower extremity vascular malformations in a high-volume experienced center where our major complication rates were 14.3% and 4.7%, respectively, which compare favorably or similar to those reported in most recent literature. These outcomes will direct treatment strategies to avoid local and systemic toxic complications in the upper and lower extremity, for both HFVM and LFVM, and to improve informed consent.

Capillary-venule malformation is a microfistulous variant of arteriovenous malformation

OBJECTIVE

To describe typical clinical presentation of patients with microfistular, capillary-venule (CV) malformation as a variant form of arteriovenous malformations (AVM).

METHODS

A retrospective clinical analysis of 15 patients with CV-AVM confirmed by a computational flow model enrolled in a prospective database of patients with congenital vascular malformation between January 2008 and May 2018.

RESULTS

The mean age of the patients at first time of presentation was 30 years with balanced sex ratio. Presentation was dominated by soft tissue hypertrophy (n = 12 [80.0%]) and atypical varicose veins (n = 11 [73.3%]). The anatomic location of enlarged varicose veins gave no uniform pattern and did not correspond with the typical picture of primary varicose vein disease. Most often, symptomatic CV-AVM was found at the lower extremities in this series of unselected patients. The most frequent compartment affected was the subcutis (n = 14 [93.3%]), involvement of muscle was recorded in one-third and cutis in one-fourth of patients.

CONCLUSIONS

A high grade of clinical suspicion is needed to recognize CV-AVM and to prevent inadequate therapy owing to missed diagnosis.

Clinical Course of Extracranial Arteriovenous Malformations

PURPOSE

Despite many advances in the knowledge of vascular malformations, extracranial arteriovenous malformations (AVMs) remain an enigma and are usually misdiagnosed and mismanaged due to their associated rare morbidity. This study aimed to describe the clinical course and emphasize the progressive nature of AVMs through a retrospective study of 446 patients.

METHODS

Patients with cutaneous and soft-tissue AVMs presenting to our Vascular Anomalies Center between March 2011 and March 2017 were reviewed. Medical records were examined for disease course, age at first presentation at our institution, distributions and locations of lesions, clinical staging, progression, and previous treatments. Progression was defined as advancement to a higher Schobinger stage from a lower stage.

RESULTS

A total of 446 patients (mean age, 25.6 ± 14.0 years) were enrolled in this study, including 232 (52.0%) males (gender ratio, 1.08:1). Arteriovenous malformations lesions in 76.7% (342/446) of the patients were located in the head and neck. Children with Stage I AVMs had a 41.9% risk of progression before adolescence and an 80.0% risk of progression before adulthood. Nearly all patients (96.2%) showed progression in adulthood. Diffuse lesions were more likely to progress than localized lesions (P < 0.05) in childhood and adolescence. Lesions in the head and neck regions were less likely to progress than those in other regions in childhood (P = 0.005). A total of 216 (48.4%) patients had undergone previous treatments. Among these patients, bleomycin showed an unintentional positive effect in the treatment of AVMs.

CONCLUSIONS

Extracranial AVMs have a continuously progressive nature. A full understanding regarding the progressive course of AVMs can lead patients and physicians to attach importance to early diagnosis and management. Meanwhile exploring innovative treatments should be focused in the future to prevent potential destructive progression.

Sclerotherapy with Adjunctive Stasis of Efflux (STASE) in Venous Malformations: Techniques and Strategies

Venous malformations are very commonly encountered in interventional radiologic practice. Indications for therapy are clearly defined based on the lesion's impact on patient's quality of life. Screening laboratory coagulation studies in patients with historical or lesion morphologic risk factors often reveal abnormal coagulation parameters consistent with localized intravascular coagulation or more severe coagulopathic states. These may require chronic or periprocedural medical management to avoid potentially life-threatening disseminated intravascular coagulation or other thromboembolic phenomena. Once a multidisciplinary decision to treat a venous malformation is made, one must decide between percutaneous and/or surgical techniques. Sclerotherapy with adjunctive stasis of efflux (STASE) techniques have become the mainstay of therapy for most venous malformations as they are well-tolerated and effective. STASE techniques work primarily by (i) the administration of sclerosant(s) exerting an inhibitory and/or endotheliocidal effect on venous malformation endothelium leading to thrombosis, involution, and fibrosis, and secondarily via adjunctive outflow occlusion using any combination of local compression, balloons, gelatin, coils, laser, radiofrequency, or adhesives to improve sclerosant penetration and dwell-time in the lesion. Adhesives alone can fill the lesion to facilitate surgical resection in some cases. Common sclerosants in modern practice include sodium tetradecyl sulfate, bleomycin, polidocanol, ethanol, and hypertonic saline. Most agents can be given directly in unmodified or "neat" form or can be mixed with a gas to form a sclerofoam or embolic such as gelatin to form a sclerogel. Choice and method of sclerosant delivery in each patient is based on the intraluminal lesion volume, architecture, vital structure proximity, agent toxicity, viscosity, and level of experience of the interventional radiologist with that particular agent. Multi-session STASE therapy usually reduces symptoms of chronic pain or mass with low risk of known complications of skin or nerve impairment, compartment syndrome, hemoglobinuria, deep venous thrombosis, or pulmonary phenomena.

Subclassification and Treatment Results of Ethanol Embolotherapy of Type II Arteriovenous Malformations of the Extremity and Body

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.

Case Report of Ethanol and Cyanoacrylate Embolisation of a Recurrent Uncontrollable Torrentially Bleeding Arteriovenous Malformation of the Finger

Introduction

In general, arteriovenous malformations (AVMs) are extremely rare, with an incidence of only 1 in 100,000. They are rarer still in the hands and present variably with bleeding, heaviness, a pulsatile mass, pain, ulceration, or necrosis.

Report

The case of a 25 year old man with a rapidly bleeding right thumb AVM is presented. Bleeding was torrential and life threatening within a matter of seconds. He had previously undergone surgical ligation and embolisation twice at another centre, without success. At presentation, he had no thumb function and the bones of the thumb were exposed. An angio-embolisation was performed with ethanol and cyanoacrylate as the embolic agent. This was done using direct puncture into the AVM and also with a transarterial approach with microcatheters inserted into various unnamed branches feeding the AVM. Non-target embolisation and reflux was prevented by deploying a pneumatic tourniquet and mechanical elastic bands to confine the flow of the embolic agents within the AVM. Re-aspiration of the embolic agent post-embolisation was also performed to prevent local/systemic ethanol toxicity. Haemostasis was achieved without the need for further compression. A right thumb disarticulation was subsequently performed and the patient expressed great satisfaction with the outcome.

Discussion

AVMs in the hand are particularly challenging to treat owing to the need to preserve function of the myriad tissues and structural units that enable the many hand movements involved in activities of daily living. Even a partial loss of function may be disabling or poorly tolerated. The mainstays of treatment are embolisation, sclerotherapy, and surgical ligation/resection, all of which carry the potential for ischaemic injury to muscle and soft tissue. A holistic approach to management is desirable prior to selecting the appropriate management plan.

•

Finger arteriovenous malformations (AVMs) are rare.

•

Treatment of hand AVMs is associated with high complication rates and functional decline.

•

Endovascular techniques can maintain function without permanent disability or recurrence.

•

Ethanol ablation has shown permanence in AVM of the extremities.

•

Use of glue and ethanol slows down the passage of ethanol, limiting collateral tissue damage.

Complications After Treatment of Head and Neck Venous Malformations With Sodium Tetradecyl Sulfate Foam

PURPOSE

The aim of this study was to evaluate complications in patients with head and neck venous malformations (VMs) treated with foam sclerotherapy using sodium tetradecyl sulfate (STS).

METHODS

The authors retrospectively evaluated the complications, pain. and degree of satisfaction in 69 consecutive patients affected by cervicofacial VM managed with STS using the Tessari method in a single institution.

RESULTS

The average number of procedures for each patient was 2.1. The most frequent complication was blistering. We observed 1 patient of temporary weakness of a facial nerve branch, 1 paradoxical embolism, and 1 orbital compartment syndrome.The average pain score was 0 (no pain at all) (51.5%). There was no statistically significant correlation between patient satisfaction and the presence of complications or the degree of pain.

CONCLUSIONS

Sclerotherapy with STS is an effective treatment that yields to very high patient satisfaction. This procedure has an overall low complication rate and is usually effective within a few sessions. However, severe complications may occur; these must be pointed out in the informed consent and the surgeon must be aware of and ready to quickly treat them to prevent long-term sequelae.

Absolute Ethanol Embolization Combined with Surgical Resection of Scalp Arteriovenous Malformations: Interim Results

PURPOSE

To assess treatment methods, interim results, and complications of absolute ethanol embolization combined with surgical resection of scalp arteriovenous malformations (AVMs).

MATERIALS AND METHODS

From September 2012 to January 2015, 15 consecutive patients (8 male and 7 female) with scalp AVMs underwent staged ethanol embolizations. Ethanol embolization was performed using transcatheter and/or direct puncture techniques. Ten patients with scalp AVMs with a dominant outflow vein (DOV) also underwent coil deployment before ethanol embolization. Two patients underwent surgical resection after ethanol embolization was achieved. Follow-up evaluations included clinical outcome of symptoms and signs and imaging at 1.5 months, 6 months, and annually thereafter.

RESULTS

In 15 patients, 33 ethanol embolizations were performed; 16 coil deployments were performed in 10 patients who had scalp AVMs with a DOV. Of 15 patients, 8 (53.3%) were cured, 2 of whom underwent surgical resection. All 8 patients showed no recurrence in the follow-up period (range, 12-48 months; mean, 25 months). Seven patients (46.7%) had partial remission and will need further treatment sessions for residual AVMs (range, 1-12 months; mean, 7 months). In 3 of 15 patients (20%), 7 minor complications (skin blisters and necrosis) occurred. All minor complications healed with wound dressing and observation. There were no major complications.

CONCLUSIONS

Ethanol embolization has the potential for cure in management of scalp AVMs, with an acceptable risk of minor and major complications. Once AVMs are devascularized, surgical resection can be performed to improve cosmetic results.

Treatment of Early-stage Extracranial Arteriovenous Malformations with Intralesional Interstitial Bleomycin Injection: A Pilot Study

Purpose To assess the efficacy and safety of intralesional interstitial bleomycin injection in the treatment of early-stage (Schobinger stage I or II) extracranial arteriovenous malformations (AVMs). Materials and Methods This prospective study involved 34 patients with early-stage AVMs, as defined by the Schobinger staging system. The patients received intralesional interstitial bleomycin injected at a maximum dose of 15 000 IU or 1000 IU per kilogram of body weight for children who weighed less than 15 kg per procedure for a total of 6 months (once every month). Therapeutic outcome was evaluated by the degree of devascularization at angiography and the clinical outcome 3 months after the last treatment. Further follow-up was evaluated based on further clinical outcome. Adverse events were recorded according to the Society of Interventional Radiology classification. Results Of the 34 patients with early-stage AVM, 32 (mean age, 20.5 years; 24 female [75%]) completed the study. The results showed that 27 (84.4%, 95% confidence interval [CI]: 71.1, 97.7) patients were responsive to bleomycin injection, including nine (28.1%) with a complete response. Four (12.5%) patients showed no response, and one (3.1%) patient experienced worsening 3 months after the last treatment. During further follow-up (mean follow-up time, 20.7 months; range, 5-28 months), the outcome remained stable in 31 (96.9%) of the 32 patients. A major complication, anaphylactic shock, was observed in one (3.1%, 95% CI: 0, 9.5) patient. Common minor complications included hyperpigmentation, nausea, pruritus, and bullae. Conclusion Intralesional interstitial bleomycin injection is a feasible approach for early-stage AVMs and yields safe and effective outcomes. ^© RSNA, 2017.

New Treatment Approaches to Arteriovenous Malformations

Arteriovenous malformations (AVMs) are high-flow vascular anomalies that have demonstrated a very high recurrence rate after endovascular treatment, surgical treatment, or a combination of both. Surgical treatments have shown good response when they are small and well localized but a poor response when diffuse. A better understanding of the nature of the lesion has led to a better response rate and a safer treatment for these patients. This has been accomplished through a detailed understanding of the angioarchitecture of the lesion, enabling a tailored approach in reaching and targeting the nidus of the AVM with different liquid embolic agents, more specifically ethanol. Flow reduction techniques help in exposing the nidus to sclerosant agents. A clinical classification, the Schobinger classification, will help determine the appropriate time to start or to pursue therapy.

An Unusual Case of Giant Arterio-Venous Malformation of Anterior Abdominal Wall

Arterio-Venous Malformations (AVMs) are high flow vascular anomalies, commonly seen in head, neck and extremities. AVMs represent a direct connection between the arterial and the venous systems. They are congenital, often asymptomatic and rarely manifest before adolescence. Depending on the site, size and symptoms, treatment options varies from conservative management to surgical resection. Here, we report a case of 20-year-old male patient with long standing lump in the anterior abdominal wall with no typical clinical features of vascular lesions. However, imaging findings were suggestive of vascular malformation, and final histopathological examination revealed arterio-venous malformation.

Embolisation of an extensive arteriovenous malformation of the temporal region as an alternate treatment: case report

Objectives:

To report the case of a spontaneous arteriovenous malformation involving the auricula, external auditory meatus, middle ear and part of the petrous apex, and also to provide updated information about its management.

Case report:

A 33-year-old woman presented complaining of accelerated growth of a retro-auricular swelling during her latest pregnancy, together with pain, pulsatile tinnitus and ear discharge. An arteriovenous malformation occupying the right auricula, external auditory canal, mastoid proccess of the temporal bone and the lateral half of the petrous segment was diagnosed, using temporal computerised tomography and magnetic resonance imaging. The lesion was embolised with polyvinyl alcohol particles at angiography. Excision of the arteriovenous malformation nidus was performed. Three years post-operatively, magnetic resonance imaging showed no residual lesion or recurrence at the temporal bone and petrous apex, although a few scanty, serpiginous, vascular remnants had persisted.

Conclusions:

In the head and neck, arteriovenous malformations usually occur intracranially; they are rare outside the cranium. To our knowledge, there have been no previously published cases of such an extensive arteriovenous malformation involving the temporal region. Apropos of our case, the definition, clinical findings, diagnostic approaches and therapeutic management of arteriovenous malformations are discussed.

Republished: Transvenous ethanol sclerotherapy of feeding arteries for treatment of a dural arteriovenous fistula

Dural arteriovenous fistulas (DAVFs) can be complex lesions that require a well trained eye for proper characterization and management decisions. With numerous possible arteries to supply and veins to drain them, DAVFs are often complex lesions. To best treat these complex lesions, the neurointerventionalist should be adept at treating them with multiple techniques. This report describes a unique case in which a DAVF was treated with arterial sclerotherapy using ethanol from a transvenous approach.

Embolization of Congenital Renal Arteriovenous Malformations Using Ethanol and Coil Depending on Angiographic Types

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.

Treatment of glomus tympanicum tumors by preoperative embolization and total surgical resection

PURPOSE

The purpose of this study was to evaluate the effectiveness on function preservation and tumor control of the treatment of glomus tympanicum tumors with pre-operative embolization followed by total surgical resection.

MATERIAL AND METHODS

We describe a series of 6 patients with a glomus tympanicum tumor who were treated in our hospital using the same technique: the day before surgery selective tumor embolization due to denaturation with 96% ethanol. Following parameters were considered: tumor classification, tumor control, clinical and audiological outcome, effectiveness of embolization, percentage of tumor necrosis and treatment complications.

RESULTS

There were no severe complications due to embolization or surgery. Tumor blush disappeared completely in 5 patients on DSA post embolization and histologic evaluation of the resected tissue showed a median of 69.2% of tumor necrosis. Pulsatile tinnitus disappeared in all patients and 3 patients had no symptoms at all. Hearing ameliorated in 4 patients, 1 patient without hearing loss pre- treatment still had normal hearing after treatment and 1 patient's hearing was worse after treatment. Average follow-up was 21.3months.

CONCLUSIONS

Treatment of glomus tympanicum tumors by pre-operative embolization with ethanol and surgical resection has not been described before. Our results show that it is a safe procedure with a good long term tumor control, good clinical and audiological outcome.

Thrombosis of pancreatic arteriovenous malformation induced by diagnostic angiography: case report

Background

We report on a case of pancreatic arteriovenous malformation (PAVM) that obliterated shortly after diagnostic angiography (DSA). PAVM is a rare anomaly that presents with upper abdominal pain, signs of acute pancreatitis and massive gastrointestinal bleeding. The management of PAVM is rather complex, with complete treatment usually accomplished only by a total extirpation of the affected organ or at least its involved portion. DSA prior to treatment decisions is helpful for characterizing symptomatic PAVM, since it can clearly depict the related vascular networks. In addition, interventional therapy can be performed immediately after diagnosis.

Case presentation

A 39-old male was admitted due to recurring upper abdominal pain that lasted several weeks. Initial examination revealed the absence of fever or jaundice, and the laboratory tests, including that for pancreatic enzymes, were unremarkable. An abdominal ultrasound (US) showed morphological and Doppler anomalies in the pancreas that were consistent with a vascular formation. A subsequent DSA depicted a medium-sized nidus, receiving blood supply from multiple origins but with no dominant artery. Coil embolization was not possible due to the small caliber of the feeding vessels. In addition, sclerotherapy was not performed so as to avoid an unnecessary wash out to the non-targeted duodenum. Consequently, the patient received no specific treatment for his symptomatic PAVM. A large increase in pancreatic enzymes was noticed shortly after the DSA procedure. Imaging follow-up by means of CT and MRI showed small amounts of peripancreatic fluid along with a limited area of intra-parenchymal necrosis, indicating necrotizing pancreatitis. In the post-angiography follow-up the patient was hemodynamically stable the entire time and was treated conservatively. The symptoms of pancreatitis improved over a few days, and the laboratory findings returned to normal ranges. Long-term follow-up by way of a contrast-enhanced CT revealed no recanalization of the thrombosed PAVM.

Conclusion

The factors associated with the obliteration of PAVM during or after DSA are poorly understood. In our case it may be attributed to the low flow dynamics of PAVM, as well as to the local administration of a contrast agent. Asymptomatic PAVM, as diagnosed with non-invasive imaging techniques, should not be evaluated with DSA due to the potential risk of severe complications, such as acute pancreatitis.

Pediatric Interventional Radiology: Vascular Interventions

Pediatric interventional radiology (PIR) comprises a range of minimally invasive diagnostic and therapeutic procedures that are performed using image guidance. PIR has emerged as an essential adjunct to various surgical and medical conditions. Over the years, technology has undergone dramatic and continuous evolution, making this speciality grow. In this review, the authors will discuss various vascular interventional procedures undertaken in pediatric patients. It is challenging for the interventional radiologist to accomplish a successful interventional procedure. There are many vascular interventional radiology procedures which are being performed and have changed the way the diseases are managed. Some of the procedures are life saving and have become the treatment of choice in those patients. The future is indeed bright for the practice and practitioners of pediatric vascular and non-vascular interventions. As more and more of the procedures that are currently being performed in adults get gradually adapted for use in the pediatric population, it may be possible to perform safe and successful interventions in many of the pediatric vascular lesions that are otherwise being referred for surgery.