Radiofrequency Ablation of the Marginal Venous System in Patients with Venous Malformations

Anticoagulation and vascular anomalies

A State of the Art lecture titled "Anticoagulation and Vascular Anomalies" was presented at the International Society on Thrombosis and Haemostasis (ISTH) Congress in 2023. Vascular anomalies have been classified by the International Society for the Study of Vascular Anomalies into vascular tumors and vascular malformations. Although some vascular tumors, such as tufted angioma and kaposiform hemangioendothelioma, and other vascular malformations can present with coagulation aberrancies, these are not generally managed with anticoagulation. A subclassification of vascular malformations includes slow-flow vascular malformations. It is this subgroup specifically that has a high risk of venous thromboembolism (VTE) and morbidity associated with coagulopathy that may be present. In these select cases, anticoagulation may be indicated to reduce the risk of VTE, treat VTE, or manage localized thrombosis in the malformation that causes significant pain and reduced quality of life. There are established risk factors for VTE in these patients that will be reviewed. Finally, we summarize relevant new data on this topic presented during the 2023 ISTH Congress.

Endoscopic Resection for Vascular Anomalies in Children: A New Standard

OBJECTIVE

To report an innovative endoscopic surgery for subcutaneous vascular malformations and intramuscular fibro-adipose vascular anomaly (FAVA) at our center.

BACKGROUND

Historically, open surgical resection has been the treatment of choice. Recent advances in minimally invasive surgery have led to the successful application of endoscopic resection techniques for the surgical management of diseases of soft tissue.

METHODS

Patients who underwent endoscopic resection of vascular anomalies were included in this retrospective review. Data were extracted from our Vascular Anomalies Center database between September 2019 and October 2022, including sex, age, symptoms, diagnosis, sites of surgery, previous treatment, surgery, and follow-up.

RESULTS

There were 13 females and 15 males in the current study, with ages ranging from 1 to 17 years. The diagnoses included microcystic lymphatic malformation (LM) (n = 8), Klippel-Trénaunay syndrome (n = 7), venous malformation (n = 6), FAVA (n = 6), and mixed cystic LM (n = 1). Surgical sites included the lower extremity (n = 24), abdominal wall (n = 2), upper extremity (n = 1), and thoracic wall (n = 1). Five patients had an intramuscular lesion (FAVA). The endoscopic technique used 2 or 3 small ports in a gas inflation manner. Surgery included thrombectomy, radical resection, and debulking of vascular anomalies. Postoperative sclerotherapy with bleomycin was performed through a drainage tube in 6 patients with microcystic LM. Technical success was obtained in 27 patients. The conversion to open surgery was performed in one patient owing to the deep location of the lesion. No wound-related complication was observed.

CONCLUSIONS

Endoscopic surgery is a minimally invasive, effective, and safe treatment for subcutaneous vascular malformations and intramuscular FAVA. This approach can set a new standard that minimizes wound complications and reduces recovery time in patients undergoing resection for benign soft-tissue lesions.

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.

Interventionelle Behandlungsoptionen bei vaskulären Malformationen

Klassifikation von vaskulären Malformationen Während Hämangiome zu den vaskulären Tumoren zählen, sind vaskuläre Malformationen angeboren und bilden sich von selbst nicht zurück. Sie werden nach der ISSVA-Klassifikation unterschieden.

Indikation zur Therapie Ziele der Therapie von Gefäßmalformationen sind die Linderung der Symptome, der Organerhalt und die Verhinderung von Krankheitsprogress und Komplikationen.

Nichtinvasive Therapieoptionen Die Kompressionstherapie sowie physiotherapeutische Maßnahmen zählen zu den wichtigsten konservativen Therapieoptionen.

Invasive Therapieoptionen Die chirurgische Resektion, die oberflächliche Lasertherapie und die interventionelle Therapie stellen die invasiven Therapieoptionen dar. Für die Behandlung symptomatischer Gefäßmalformationen stehen mittlerweile zahlreiche minimalinvasive interventionelle Verfahren zur Verfügung. Slow-Flow-Malformationen können relativ komplikationsarm mittels perkutaner Sklerotherapie behandelt werden, die zu einem zeitversetzten entzündlichen Verschluss der Läsion führt. Dysplastische Venen wie die Marginalvene können mittels endoluminaler Verfahren erfolgreich verödet werden. Die zumeist Katheter-gesteuerten Embolisationsverfahren mittels Flüssigembolisaten, Plugs und Coils erlauben den Verschluss von Fast-Flow-Gefäßmalformationen.

Interventional Treatment Options in Children with Extracranial Vascular Malformations

Extracranial vascular malformations vary greatly and belong to the complex field of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic system. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) represents an important guidance for selecting appropriate therapy. Although many of the principles of endovascular treatment, including image-guided sclerotherapy and embolization, are similar in adult and pediatric practice, there are some distinct differences regarding the treatment of vascular malformations of children. Thus, it is crucial to involve longer-term plan about managing these chronic diseases and their impact on a growing child. This review provides a detailed overview over the clinical presentation of venous, lymphatic, and arteriovenous malformations in children and emphasizes the specifics of their interventional treatment options, including distinct pediatric dose limitations and procedure-related side effects.

Internal Iliac Vein Reflux: An Underrecognized Pathophysiology in Klippel-Trénaunay Syndrome With Pelvis Involvement

Background and objective

Internal iliac vein reflux (IIVR) has been underrecognized in Klippel-Trénaunay syndrome (KTS) with pelvis involvement. In this study, our aim was to report clinical and radiological characteristics, modified phlebography technique, and diagnostic and treatment algorithm and outcomes of IIVR in KTS patients with pelvis involvement.

Materials and methods

KTS patients diagnosed between May 2014 and January 2021 were retrospectively analyzed. The medical records and imaging studies of all patients with KTS of the lower extremities were included and reviewed. KTS was defined as the triad of capillary malformation, venous malformation, and limb overgrowth. Pelvis involvement was evaluated with MRI. Phlebography was performed if IIVR was suspected. IIVR ablation and sclerotherapy were performed if IIVR was confirmed in KTS patients with external genitalia/perineum manifestation and bleeding. Patients were followed up via outpatient consultations. Episodes of gross bleeding were specifically investigated.

Results

A total of 211 patients with lower limb KTS diagnosed by our team were included in the study. Unilateral IIVR was diagnosed in 97 patients, and bilateral IIVR in two patients; 117 KTS patients were managed with radiological intervention and/or hybrid surgery by our team. Eleven patients underwent an IIVR ablation procedure due to recurrent bleeding from pelvic organs. Postprocedural complications included transient fever (n=2) and mild anaphylactic reaction (n=1). A small hyperpigmented scar at the incision and/or accessing site was noticed in patients receiving bleomycin during the procedure (n=6). Bleeding episodes and anemia resolved in all patients during the follow-up period. Correspondingly, the involved IIV and its tributaries were found to have disappeared on imaging during the follow-up.

Conclusion

IIVR is common in KTS patients, and it can cause bleeding from pelvic organs. Bleeding can be managed with IIVR ablation and sclerotherapy in KTS with pelvis involvement.

Contrast-enhanced ultrasound with perfusion analysis in patients with venous malformations before and after percutaneous treatment with ethanol-gel

INTRODUCTION

Percutaneous sclerotherapy is a well-established treatment option for venous malformations (VM). A recently established sclerosing agent is ethanol-gel. Aim of this study was to identify, if contrast-enhanced ultrasound (CEUS) with an integrated perfusion analysis allows for differentiation between untreated VM, healthy tissue, and with gelified ethanol treated malformation tissue.

MATERIAL AND METHODS

In this institutional review board approved prospective study symptomatic VM patients underwent CEUS at exactly the same position before and after sclerotherapy with ethanol-gel. Two experienced sonographers performed all examinations after the bolus injection of microbubbles using a multi-frequency probe with 6 -9 MHz of a high-end ultrasound machine. An integrated perfusion analysis was applied in the center of the VM and in healthy, surrounding tissue. For both regions peak enhancement (peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT) were evaluated. Wilcoxon signed rank test was executed; p-values <0.05 were regarded statistically significant.

RESULTS

In 23 patients including children (mean age 25.3 years, 19 females) before treatment all identified parameters were significantly higher in the VM center compared to healthy tissue (peak: p < 0.01; TTP: p < 0.01; AUC: p < 0.01; MTT: p < 0.01). Comparing the VM center before and after treatment, TTP (p < 0.02) and MTT (p < 0.01) reduced significantly after sclerotherapy. In surrounding tissue only peak changed after treatment in comparison to pre-treatment results (p = 0.04). Comparing data in the VM center with surrounding tissue after sclerotherapy, results still differed significantly for peak (p < 0.01), TTP (p < 0.01), and AUC (p < 0.01), but assimilated for MTT (p = 0.07).

CONCLUSION

All with CEUS identified parameters seem to be excellent tools for differentiating between VM and healthy tissue. TTP and MTT could distinguish between with ethanol-gel sclerotized VM portions and untreated malformation parts and thereby might assist the monitoring of sclerotherapy with ethanol-gel.

Evaluation and management of the lateral marginal vein in Klippel-Trénaunay and other PIK3CA-related overgrowth syndromes

The lateral marginal vein is an anomalous clinical entity found in association with Klippel-Trénaunay and other PIK3CA-related overgrowth syndromes. Although it is reported to affect <20% of patients with Klippel-Trénaunay syndrome, this venous anomaly has been associated with significant morbidity and mortality attributable to venous hypertension and potentially lethal thromboembolic events. Limited literature exists on the diagnosis and management of this rare anomaly, with most of the reports focusing on retrospective clinical experience at a few centers of excellence. Despite these limitations, a systematic approach to diagnosis and treatment of this anomaly is warranted and expounded on herein. When plausible, clinical recommendations based on best available literature are made.

Klippel-Trenaunay Syndrome

Klippel-Trenaunay syndrome or KTS is a complex vascular syndrome associated with overgrowth occurring as a result of somatic mutations in the PIK3CA gene. Patients are diagnosed on the basis of physical findings, sometimes with supportive imaging, of commonly a segmental anomaly with a cutaneous port-wine stain, lymphatic and venous malformations and overgrowth. The severity of the component vascular malformations and the degree of overgrowth varies from patient to patient which demands care given by a multi-professional team with regular follow-up in a specialist clinic. Some patients may present with acute life-threatening problems, often as a result of veno-thromboembolic events (VTEs) especially following surgical and invasive radiological procedures. Awareness of such problems is vital and prophylactic measures to reduce such risks are paramount. The interventional radiologist is vital to the care team as he/she can undertake procedures including endovascular closure of significant venous anomalies which predispose to such VTEs. Although these procedures can be lengthy and complex, they can now provide a minimally invasive means to reduce the risk from life-threatening and sometimes fatal VTEs. The results however from such interventions will require long-term studies which to date are unavailable.