Imaging of peripheral vascular malformations - current concepts and future perspectives

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

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

Dermato-Radiological Evaluation of Congenital Limb Overgrowth Vascular Syndromes

International Society for the Study of Vascular Anomalies classification defines Congenital Limb Overgrowth Vascular Syndromes (CLOS) as a subset of vascular syndromes with other abnormalities that present with unilateral limb overgrowth. It includes Klippel-Trenaunay Syndrome, Parkes-Weber Syndrome, CLOVES (Congenital Lipomatous Overgrowth, Vascular Malformations, Epidermal Nevi, Spinal/Skeletal Anomalies/Scoliosis) Syndrome, Proteus Syndrome, PTEN Hamartomatous Syndrome, and Fibroadipose Vascular Anomaly. Due to their rare and complex nature, a multidisciplinary approach to diagnosis and treatment is required. A thorough clinical and radiological workup can go miles in reflecting on the patient's outcome. Here we report five cases of CLOS with their detailed dermato-radiological profiles.

Fluoroscopy- and Endoscopy-Guided Transoral Sclerotherapy Using Foamed Polidocanol for Oropharyngolaryngeal Venous Malformations in a Hybrid Operation Room: A Case Series

Background: Treatment of oropharyngolaryngeal venous malformations (VMs) remains challenging. This study evaluated the effectiveness and safety of fluoroscopy- and endoscopy-guided transoral sclerotherapy for oropharyngolaryngeal VMs in a hybrid operation room (OR). Methods: Patients with oropharyngolaryngeal VMs who underwent transoral sclerotherapy in a hybrid OR were enrolled. Results: Fourteen patients (six females, eight males; median age of 26 years; range, 4-71 years) were analyzed. The symptoms observed were breathing difficulties (n = 3), snoring (n = 2), sleep apnea (n = 1), and swallowing difficulties (n = 1). Lesions were extensive in the face and neck (n = 9) and limited in the oropharyngolarynx (n = 5). A permanent tracheostomy was performed on two patients, while a temporary tracheostomy was performed on five patients. The treated regions were the soft palate (n = 8), pharynx (n = 7), base of the tongue (n = 4), and epiglottis (n = 1). The median number of sclerotherapy sessions was 2.5 (range, 1-9). The median follow-up duration was 81 months (range, 6-141). Treatment outcomes were graded as excellent (n = 2), good (n = 7), or fair (n = 5). The post-treatment complication was bleeding (n = 1), resulting in an urgent tracheostomy. Conclusions: Fluoroscopy- and endoscopy-guided transoral sclerotherapy in a hybrid OR can be effective and safe for oropharyngolaryngeal VMs.

Outcome of bleomycin electrosclerotherapy of slow-flow malformations in adults and children

OBJECTIVES

To evaluate the safety and clinical outcome of bleomycin electrosclerotherapy (BEST) for treating extracranial slow-flow malformations.

METHODS

In this retrospective investigation of a multicenter cohort presenting symptomatic slow-flow malformations, patient records were analyzed with respect to procedural details and complications. A treatment-specific, patient-reported questionnaire was additionally evaluated, obtained 3-12 months after the last treatment, to assess the subjective outcomes, including mobility, aesthetic aspects, and pain, as well as the occurrence of postprocedural skin hyperpigmentation. All outcome parameters were compared according to patients' age.

RESULTS

Overall, 325 BEST treatments were performed in 233 patients after intralesional and/or intravenous bleomycin injection. The total complication rate was 10.2% (33/325), including 29/352 (8.9%) major complications. Patient-reported mobility decreased in 10/133 (8.8%), was stable in 30/113 (26.5%), improved in 48/113 (42.5%), and was rated symptom-free in 25/113 (22.1%) patients. Aesthetic aspects were rated impaired compared to baseline in 19/113 (16.8%), stable in 21/133 (18.6%), improved in 62/113 (54.9%), and perfect in 11/133 (9.7%) patients. Postprocedural skin hyperpigmentation occurred in 78/113 (69%) patients, remaining unchanged in 24/78 (30.8%), reduced in 51/78 (65.5%), and completely resolved in 3/78 (3.8%) patients. The median VAS pain scale was 4.0 (0-10) preprocedural and 2.0 (0-9) postprocedural. Children/adolescents performed significantly better in all parameters compared to adults (≥ 16 years) (mobility, p = 0.011; aesthetic aspects, p < 0.001; pain, p < 0.001).

CONCLUSIONS

BEST is effective for treating slow-flow vascular malformations, with few but potentially significant major complications. Regarding patient-reported outcomes, children seem to benefit better compared to older patients, suggesting that BEST should not be restricted to adults.

CLINICAL RELEVANCE STATEMENT

Bleomycin electrosclerotherapy is a safe and effective approach and therapy should not be restricted to adults due to good clinical outcomes in children.

Extracranial Vascular Anomalies Driven by RAS/MAPK Variants: Spectrum and Genotype-Phenotype Correlations

BACKGROUND

We aimed to correlate alterations in the rat sarcoma virus (RAS)/mitogen-activated protein kinase pathway in vascular anomalies to the clinical phenotype for improved patient and treatment stratification.

METHODS AND RESULTS

This retrospective multicenter cohort study included 29 patients with extracranial vascular anomalies containing mosaic pathogenic variants (PVs) in genes of the RAS/mitogen-activated protein kinase pathway. Tissue samples were collected during invasive treatment or clinically indicated biopsies. PVs were detected by the targeted sequencing of panels of genes known to be associated with vascular anomalies, performed using DNA from affected tissue. Subgroup analyses were performed according to the affected genes with regard to phenotypic characteristics in a descriptive manner. Twenty-five vascular malformations, 3 vascular tumors, and 1 patient with both a vascular malformation and vascular tumor presented the following distribution of PVs in genes: Kirsten rat sarcoma viral oncogene (n=10), neuroblastoma ras viral oncogene homolog (n=1), Harvey rat sarcoma viral oncogene homolog (n=5), V-Raf murine sarcoma viral oncogene homolog B (n=8), and mitogen-activated protein kinase kinase 1 (n=5). Patients with RAS PVs had advanced disease stages according to the Schobinger classification (stage 3-4: RAS, 9/13 versus non-RAS, 3/11) and more frequent progression after treatment (RAS, 10/13 versus non-RAS, 2/11). Lesions with Kirsten rat sarcoma viral oncogene PVs infiltrated more tissue layers compared with the other PVs including other RAS PVs (multiple tissue layers: Kirsten rat sarcoma viral oncogene, 8/10 versus other PVs, 6/19).

CONCLUSIONS

This comparison of patients with various PVs in genes of the RAS/MAPK pathway provides potential associations with certain morphological and clinical phenotypes. RAS variants were associated with more aggressive phenotypes, generating preliminary data and hypothesis for future larger studies.

Diagnosis of a chronic wound in the special case of a vascular malformation: A proposal of the Wound and Healing Group of the French Society of Vascular Medicine

Vascular malformations can present with a variety of symptoms and an unpredictable course with the occurrence of wounds. Ulcerations in patients with vascular malformations are fortunately rare. Although few data exist, complications may involve a variety of mechanistic or hemodynamic factors. A rigorous etiological and vascular assessment is therefore essential. In view of the paucity of recommendations, the Wound and Healing Group of the French Society of Vascular Medicine, based on the literature on the subject, presents a number of suggestions for the diagnosis and management of wounds associated with vascular malformations.

Effectiveness of polidocanol sclerotherapy in alleviating symptoms in patients with venous malformations

OBJECTIVE

The objective of this study was to retrospectively evaluate the effectiveness of polidocanol in managing pain, swelling, functional limiting and cosmetic disorders in patients with venous malformations (VMs).

METHODS

This retrospective study included patients who underwent sclerotherapy with polidocanol for VMs between 2020 and 2022. Patient records, imaging findings, and evaluation questionnaires used in the preprocedure and follow-up phases were reviewed. After sclerotherapy, patients were followed up at 1, 2, 3, and 6 months. During these visits, the previously used 11-point verbal numerical rating scale (from 0 [no pain] to 10 [worst pain thinkable]) was used to evaluate the severity of symptoms such as pain, swelling, cosmetic discomfort, and functional limitation, and patients were asked to report the number of days per week they experienced these symptoms owing to the VM.

RESULTS

A total of 194 sclerotherapy procedures (mean, 1.6 ± 0.3 procedures) in 84 patients (55 female and 29 male patients; mean age, 22.45 ± 11.83 years) were conducted. The majority of these malformations (81%, or 68 patients) were located in the extremities. We found a significant decrease in pain, swelling, functional limitation, cosmetic appearance, and number of painful days between all time points, except for the comparison between months 3 and 6 (P < .001) CONCLUSIONS: Polidocanol sclerotherapy is a safe and effective treatment for VMs that significantly decreases patient complaints and has a very low complication rate. Particularly, following patients at short intervals and administering additional sclerotherapy sessions when necessary will significantly increase patient satisfaction.

Management of congenital urogenital and perineal vascular malformations: correlation of clinical findings with diagnostic imaging for treatment decision

PURPOSE

 Analysis of clinical and diagnostic findings in rare urogenital and perineal vascular malformations only occurring in 2-3 % of vascular anomalies with regard to clinical symptoms and treatment decisions.

MATERIALS AND METHODS

 All 25 out of 537 patients presenting with congenital urogenital and perineal vascular malformations at our institution from 2014 to 2021 were included. Vascular anomaly classification, anatomical location, clinical symptoms at presentation, diagnostic imaging, and pain intensity were retrospectively assessed from the patient record and therapy management was evaluated.

RESULTS

 In total, 25 patients (10 females (40 %), 15 males (60 %)), aged 6 to 77 years were included. Diagnoses were: 10 (40 %) venous malformations (VMs), 5 (20 %) lymphatic malformations (LMs) and 10 (40 %) arteriovenous malformations (AVMs). Malformation manifestations were: 12 (32 %) lesser pelvis, 12 (32 %) external genitalia, and 13 (34 %) perineal/gluteal region. One AVM was located in the kidney. The leading clinical symptom was pain. The mean intensity was 6.0/10 for LM, 5.7/10 for VM, and 4.5/10 for AVM. Further major symptoms included physical impairment, local swelling, and skin discoloration. Bleeding complications or sexual dysfunction were rare findings. Patients with VM reported significantly more symptoms than patients with AVM (p = 0.0129). In 13 patients (52 %) minimally invasive therapy was indicated: 10 (77 %) sclerotherapies and 3 (23 %) transcatheter embolization procedures. Complete symptomatic remission was achieved in 9 (69 %) patients, partial response in 3 (23 %) patients, and 1 patient showed no clinical response to therapy. Follow-up appointments without the need for immediate minimally invasive therapy were significantly more common in patients with AVMs than in patients with VMs (p = 0.0198).

CONCLUSION

 To create a higher awareness of congenital urogenital and perineal vascular malformations. Awareness of this rare condition avoids misdiagnosis. Therapy decisions should be symptom-oriented. Emergency intervention is rarely required, even in fast-flow vascular malformations.

KEY POINTS

  · Venous malformations cause more symptoms with higher pain intensity than arteriovenous malformations.. · Diagnosis and adequate treatment can be hampered by a lack of awareness of the clinical presentation.. · Bleeding complications are rare, even in high-flow vascular malformations.. · Pain and physical impairment are the most commonly observed symptoms in these patients..

A Comprehensive Review of Sonographic Assessment of Peripheral Slow-Flow Vascular Malformations

This comprehensive review explores the role of sonographic assessment in diagnosing and characterizing peripheral slow-flow vascular malformations (PSFVM). The review begins with an introduction providing the background and significance of PSFVM, defining these vascular anomalies, and emphasizing the importance of sonography in their diagnosis. The objectives focus on a thorough examination of existing literature, assessing the effectiveness of sonography in delineating morphological and hemodynamic features crucial for accurate classification. The summary of key findings highlights the diagnostic accuracy of sonography while acknowledging its limitations. Implications for clinical practice emphasize the practical utility of sonography in early diagnosis and preoperative planning, suggesting integration into multimodal approaches. The conclusion underscores the need for standardized criteria, ongoing education, and future research, positioning sonography as a valuable tool in the comprehensive management of PSFVM.

Deep learning-based differentiation of peripheral high-flow and low-flow vascular malformations in T2-weighted short tau inversion recovery MRI

BACKGROUND

Differentiation of high-flow from low-flow vascular malformations (VMs) is crucial for therapeutic management of this orphan disease.

OBJECTIVE

A convolutional neural network (CNN) was evaluated for differentiation of peripheral vascular malformations (VMs) on T2-weighted short tau inversion recovery (STIR) MRI.

METHODS

527 MRIs (386 low-flow and 141 high-flow VMs) were randomly divided into training, validation and test set for this single-center study. 1) Results of the CNN's diagnostic performance were compared with that of two expert and four junior radiologists. 2) The influence of CNN's prediction on the radiologists' performance and diagnostic certainty was evaluated. 3) Junior radiologists' performance after self-training was compared with that of the CNN.

RESULTS

Compared with the expert radiologists the CNN achieved similar accuracy (92% vs. 97%, p = 0.11), sensitivity (80% vs. 93%, p = 0.16) and specificity (97% vs. 100%, p = 0.50). In comparison to the junior radiologists, the CNN had a higher specificity and accuracy (97% vs. 80%, p < 0.001; 92% vs. 77%, p < 0.001). CNN assistance had no significant influence on their diagnostic performance and certainty. After self-training, the junior radiologists' specificity and accuracy improved and were comparable to that of the CNN.

CONCLUSIONS

Diagnostic performance of the CNN for differentiating high-flow from low-flow VM was comparable to that of expert radiologists. CNN did not significantly improve the simulated daily practice of junior radiologists, self-training was more effective.

Vascular Malformations and Tumors: A Review of Classification and Imaging Features for Cardiothoracic Radiologists

The International Society for the Study of Vascular Anomalies (ISSVA) classification is a comprehensive histology-based scheme that was updated in 2018. It is important for cardiothoracic imagers to understand this classification to ensure that accurate terminology is used and that archaic terms are avoided when vascular lesions are described. Knowledge of the various malformations (including common conditions, such as venous malformation, arteriovenous fistula, and arteriovenous malformation) and vascular tumors allows for timely diagnosis and appropriate management. This review describes various vascular anomalies, in accordance with ISSVA classification and terminology; highlights key imaging features associated with each; and discusses the role of different imaging modalities. Keywords: Pulmonary, Soft Tissues/Skin, Vascular, Arteriovenous Malformation © RSNA, 2023.

Structured magnetic resonance imaging-based characterization of the marginal vein reveals limits of the Weber-classification

Background: The marginal vein (MV) is a persisting embryonic vein located at the lateral aspect of the lower limb. The Weber-classification, which was developed on the basis of phlebography in the 1990s, is the only existing classification system for this rare disease. Aim of this study was the structured characterization of the lateral marginal vein (MV) using magnetic resonance imaging (MRI) and evaluation of the applicability of the Weber-classification. Patients and methods: Institutional Review Board approval was obtained for this retrospective, single-center study. All patients who underwent contrast-enhanced MRI (using a prospectively determined protocol) of the untreated MV were included. MV anatomy and associated findings were characterized in a structured way taking into account the criteria of the Weber-classification for MV: inflow, outflow and extension. If three criteria of the Weber-classification were fulfilled the MV was categorized as "classifiable according to Weber". The MV was categorized as "partially classifiable according to Weber", if two criteria were met and as "not classifiable according to Weber" if less than two criteria were applicable. Results: 56 imaging studies of 58 MV (7 thoracoabdominal, 51 lower extremities) were reviewed. 18/51 MV of the lower extremities were "classifiable" according to the Weber-classification. 33/51 lower extremity MV were not definitely categorized according to the Weber-classification: 19/51 MV were "partially classifiable" and 14/51 MV were "not classifiable". 30/51 MV presented with hypoplastic, 1/51 with aplastic deep venous system. 34/51 lower extremity and 6/7 thoracoabdominal MV were associated with an additional vascular malformation (VM). Conclusions: MRI is suitable for detailed anatomic characterization of the MV and reveals additional therapy relevant findings like associated VM. The Weber-classification was not applicable in most cases, reflecting its limits and the heterogeneity of this rare disease. Structured reports rather than an obsolete classification system should be preferred for MRI of the MV.

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

PURPOSE

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

MATERIALS AND METHODS

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

DISCUSSION

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

TRIAL REGISTRATION

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

Multicentered analysis of percutaneous sclerotherapies in venous malformations of the face

Objectives

To evaluate the safety and outcome of image-guided sclerotherapy for treating venous malformations (VMs) of the face.

Materials and methods

A multicenter cohort of 68 patients with VMs primarily affecting the face was retrospectively investigated. In total, 142 image-guided sclerotherapies were performed using gelified ethanol and/or polidocanol. Clinical and imaging findings were assessed to evaluate clinical response, lesion size reduction, and complication rates. Sub-analyses of complication rates depending on type and injected volume of the sclerosant as well as of pediatric versus adult patient groups were conducted.

Results

Mean number of procedures per patient was 2.1 (±1.7) and mean follow-up consisted of 8.7 months (±6.8 months). Clinical response (n = 58) revealed a partial relief of symptoms in 70.7% (41/58), 13/58 patients (22.4%) presented symptom-free while only 4/58 patients (6.9%) reported no improvement. Post-treatment imaging (n = 52) revealed an overall objective response rate of 86.5% (45/52). The total complication rate was 10.6% (15/142) including 4.2% (7/142) major complications, mostly (14/15, 93.3%) resolved by conservative means. In one case, a mild facial palsy persisted over time. The complication rate in the gelified ethanol subgroup was significantly higher compared to polidocanol and to the combination of both sclerosants (23.5 vs. 6.0 vs. 8.3%, p = 0.01). No significant differences in complications between the pediatric and the adult subgroup were observed (12.1 vs. 9.2%, p = 0.57). Clinical response did not correlate with lesion size reduction on magnetic resonance imaging (MRI).

Conclusion

Image-guided sclerotherapy is effective for treating VMs of the face. Clinical response is not necessarily associated with size reduction on imaging. Despite the complex anatomy of this location, the procedures are safe for both adults and children.

Image-Guided Embolotherapy of Arteriovenous Malformations of the Face

PURPOSE

To evaluate the safety and outcome of image-guided embolotherapy of extracranial arteriovenous malformations (AVMs) primarily affecting the face.

MATERIALS AND METHODS

A multicenter cohort of 28 patients presenting with AVMs primarily affecting the face was retrospectively investigated. Fifty image-guided embolotherapies were performed, mostly using ethylene-vinyl alcohol copolymer-based embolic agents. Clinical and imaging findings were assessed to evaluate response during follow-up (symptom-free, partial relief of symptoms, no improvement, and progression despite embolization), lesion devascularization (total, 100%; substantial, 76-99%; partial, 51-75%; failure, < 50%; and progression), and complication rates (classified according to the CIRSE guidelines). Sub-analyses regarding clinical outcome (n = 24) were performed comparing patients with (n = 12) or without (n = 12) subsequent surgical resection after embolotherapy.

RESULTS

The median number of embolotherapy sessions was 2.0 (range, 1-4). Clinical outcome after a mean follow-up of 12.4 months (± 13.3; n = 24) revealed a therapy response in 21/24 patients (87.5%). Imaging showed total devascularization in 14/24 patients (58.3%), including the 12 patients with subsequent surgery and 2 additional patients with embolotherapy only. Substantial devascularization (76-99%) was assessed in 7/24 patients (29.2%), and partial devascularization (51-75%) in 3/24 patients (12.5%). Complications occurred during/after 12/50 procedures (24.0%), including 18.0% major complications. Patients with subsequent surgical resections were more often symptom-free at the last follow-up compared to the group having undergone embolotherapy only (p = 0.006).

CONCLUSION

Image-guided embolotherapy is safe and effective for treating extracranial AVMs of the face. Subsequent surgical resections after embolization may substantially improve patients' clinical outcome, emphasizing the need for multimodal therapeutic concepts.

LEVEL OF EVIDENCE

Level 4, Retrospective study.

Diffusion-Weighted Imaging Prior to Percutaneous Sclerotherapy of Venous Malformations—Proof of Concept Study for Prediction of Clinical Outcome

Prediction of response to percutaneous sclerotherapy in patients with venous malformations (VM) is currently not possible with baseline clinical or imaging characteristics. This prospective single-center study aimed to predict treatment outcome of percutaneous sclerotherapy as measured by quality of life (QoL) by using radiomic analysis of diffusion-weighted (dw) magnetic resonance imaging (MRI) before and after first percutaneous sclerotherapy. In all patients (n = 16) pre-interventional (PRE-) and delta (DELTA-) radiomic features (RF) were extracted from dw-MRI before and after first percutaneous sclerotherapy with ethanol gel or polidocanol foam, while QoL was assessed using the Toronto Extremity Salvage Score (TESS) and the 36-Item Short Form Survey (SF-36) health questionnaire. For selecting features that allow differentiation of clinical response, a stepwise dimension reduction was performed. Logistic regression models were fitted and selected PRE-/DELTA-RF were tested for their predictive value. QoL improved significantly after percutaneous sclerotherapy. While no common baseline patient characteristics were able to predict response to percutaneous sclerotherapy, the radiomics signature of VMs (independent PRE/DELTA-RF) revealed high potential for the prediction of clinical response after percutaneous sclerotherapy. This proof-of-concept study provides first evidence on the potential predictive value of (delta) radiomic analysis from diffusion-weighted MRI for Quality-of-Life outcome after percutaneous sclerotherapy in patients with venous malformations.