Laser ablation of embryonic veins in children

Venous Anomalies in Overgrowth Syndromes

Overgrowth syndromes, particularly within the PIK3CA-related overgrowth syndrome (PROS) spectrum, are commonly associated with venous anomalies. The anomalies include spongiform venous malformations and persistent embryonic veins, such as the lateral marginal vein (of Servelle). The anomalous veins pose a significant risk of thromboembolic disease and should be occluded, preferably earlier in life. A thorough understanding of the conditions, anatomy, and interdisciplinary treatment of these complex anomalies is essential for optimal management. This review explores the clinical and imaging diagnosis of overgrowth syndromes and techniques for assessing and treating associated venous anomalies, particularly the endovenous closure of anomalous veins.

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.

An overview of interventional radiology techniques for the diagnosis and management of vascular anomalies: Part 2

Minimally invasive percutaneous and endovascular strategies performed by interventional radiologists have become the mainstays of treatment for vascular anomalies with improved outcomes, decreased complication rates, and less morbidity. The aim of this article is to introduce physicians who care for patients with vascular anomalies to state-of-the-art advancements in interventional radiology for diagnosis and treatment. Part 2 of this review discusses embolization, endovenous laser ablation, and image-guided percutaneous biopsy. Please see Part 1 for a discussion of sclerotherapy and cryoablation. Select vascular anomalies will be discussed as examples to highlight IR diagnostic and/or treatment techniques.

Klippel–Trenaunay Syndrome: Employment of a New Endovascular Treatment Technique—Mechanochemical Ablation Using the Flebogrif System

Background: Klippel–Trenaunay syndrome (KTS) is characterized by a triad of symptoms; varicose veins and venous malformations (VMs), capillary malformations (port-wine stain), and soft tissue and bone hypertrophy. Herein, we retrospectively studied six patients with KTS who underwent treatment with the Flebogrif system and evaluated their outcomes. Methods: Six KTS patients aged 16–22 years who had undergone 18 non-thermal ablations using the Flebogrif system were enrolled. All patients underwent multistage foam sclerotherapy with 3% polidocanol at 3–4-week intervals. Results: Venous clinical severity score (VCSS) analysis showed improvement in the patients’ clinical condition. All patients reported a significant improvement in aesthetic outcomes. One patient presented with recanalization of ablated marginal veins during the 24-month follow-up period. Patients could return to full activity within 7–10 days after the procedure. None of the patients experienced serious systemic complications. Conclusion: The use of the Flebogrif system in treating various forms of chronic venous insufficiency, including in patients with KTS, provides a high success rate with a high closure rate.

Clinical presentation and outcomes after endovascular management in a mixed pediatric and adult Klippel-Trenaunay syndrome population

OBJECTIVE

We retrospectively studied the clinical presentations and outcomes of endovascular management in a mixed pediatric and adult Klippel-Trenaunay syndrome (KTS) population at a single academic medical center.

METHODS

We performed a retrospective study of patients with KTS who had been referred for endovascular intervention after evaluation and diagnosis by a multidisciplinary team at a single academic medical center during a 10-year period. The patient demographics, areas affected, presenting symptoms, previous treatments, imaging modalities, endovascular treatment types, number of treatments, and complications were assessed. The technical and clinical success rates were calculated.

RESULTS

Twenty-six patients with suspected KTS were evaluated. Of these 26 patients, 20, aged 2 to 75 years, had been diagnosed with KTS using the International Society for the Study of Vascular Anomalies criteria and referred for endovascular management. The left lower extremity was affected most often. The presenting symptoms were pain (80%), edema (70%), bleeding (10%), numbness (25%), and claudication (25%). Of the 20 patients, 16 (80%) had undergone treatment of KTS before presenting to our institution. Magnetic resonance imaging and ultrasound (US) were the most common imaging modalities. Fifteen patients underwent 46 endovascular treatments during the study period. The treatments included 5 endovenous ablations only, 4 US-guided sclerotherapies with endovenous ablation, 5 US-guided sclerotherapies only, and 32 catheter-directed venograms with additional interventions. Localized intravascular coagulopathy was the only procedure-related complication and occurred in one patient after three treatments. The technical success rate was 97.8%, and the clinical success rate was 100%.

CONCLUSION

Endovascular intervention is safe and effective for KTS patients for whom conservative management has failed. Pain and edema were the most common presenting symptoms. Presenting symptoms may be related to pathology of anomalous veins, orthotopic superficial veins or deep veins. Venous claudication can be present in those with KTS despite patency of the deep venous system. Magnetic resonance imaging and duplex US are frequently used modalities for venous assessment. The complications of endovascular treatment are rare but include localized intravascular coagulopathy.

Mechanochemical Endovenous Ablation of Varicose Veins in Pediatric Patients with Klippel-Trénaunay Syndrome: Feasibility, Safety, and Initial Results

PURPOSE

To evaluate feasibility, safety, and results of endovenous mechanochemical ablation (MOCA) for treatment of persistent embryonic and dysplastic veins in pediatric patients with Klippel-Trénaunay syndrome (KTS).

MATERIALS AND METHODS

Thirteen MOCA procedures were performed in 11 patients (age range, 4-16 years) with KTS and symptomatic persistent embryonic or dysplastic veins during a 24-month period. All patients were evaluated with color Doppler (CD) ultrasound (US), contrast-enhanced MR imaging, and venography to assess the anatomy of the target vessels and patency of the deep venous system. All procedures were performed under general anesthesia with a ClariVein catheter and liquid sodium tetradecyl sulfate as the sclerosing agent. US and fluoroscopic guidance were used in all cases. Technical success rate, primary occlusion rate, adverse effects, and recanalization rates were evaluated. Clinical and radiological (CD US) controls were performed 1 day, 7 days, 1 month, and 6 months after the procedure and once a year thereafter, with a mean follow-up of 16 months (range, 6-25 months).

RESULTS

Technical success and primary occlusion were achieved in all patients with no adverse events. During the follow-up period, CD US demonstrated partial recanalization and symptom recurrence in 2 patients (18%), 14 and 18 months after the initial procedure. These 2 patients had a second ablation procedure with no recanalization or symptom recurrence during the subsequent follow-up period.

CONCLUSIONS

MOCA is feasible and appears to be a safe and effective technique for treatment of varicose veins in pediatric patients with KTS.

PIK3CA vascular overgrowth syndromes: an update

PURPOSE OF REVIEW

Over the past decade many previously poorly understood vascular malformation disorders have been linked to somatic activating mutations in PIK3CA, which regulates cell survival and growth via activation of the mTOR1-AKT pathway. The goal of this article is to describe and provide an update on the clinical features, complications, and management strategies for the PIK3CA-related overgrowth spectrum (PROS).

RECENT FINDINGS

PROS encompasses a heterogenous group of disorders with complications related to the tissues harboring the mutation. Vascular malformation syndromes, such as Klippel-Trenaunay syndrome and Congenital Lipomatous Overgrowth Vascular malformations Epidermal nevi and Skeletal abnormalities, have an increased risk of thromboembolic complications, which is accentuated postprocedurally. Asymmetric overgrowth, particularly of limbs, results in a high rate of orthopedic complications. Hypoglycemia screening in the neonatal period and ongoing monitoring for growth failure is recommended in megalencephaly capillary malformation due to its association with multiple endocrinopathies. Recently, sirolimus, an mTOR1 inhibitor, has shown promise in vascular anomalies and now PROS. PIK3CA direct inhibitor, Alpelisib (BYL719), was recently trialed with significant clinical benefit.

SUMMARY

As the pathogenesis of these conditions is better elucidated and targeted treatments are developed, recognizing the clinical features, comorbidities, and evolving therapeutic landscape across the PROS spectrum becomes more crucial for optimization of care.

Genitourinary involvement in pediatric patients with Klippel-Trenaunay Syndrome

BACKGROUND

Klippel-Trenaunay Syndrome (KTS) is a genetic vascular malformation disorder which induces a variety of phenotypic expression in patients which differ in terms of severity/location. While previous studies have documented genitourinary (GU) complications in adult KTS patients, documentation of the scope and incidence of GU involvement in the pediatric population with imaging findings is currently limited. This study represents the largest KTS genitourinary review to date.

OBJECTIVE

To assess the incidence, scope, clinical findings and imaging characteristics of GU pathology in pediatric KTS patients.

MATERIALS/METHODS

Using a retrospective data analysis design, the charts and imaging studies of pediatric KTS patients were reviewed. All patients received care at a specialized vascular clinic within a multicenter tertiary care system. Variables studied included age, age at KTS diagnosis, gender, urologic involvement, and age of urologic complication.

RESULTS

58 patients were identified. 33 were male and 25 were female. 10 patients had GU findings. Three of these patients had multifocal GU involvement (greater than 1 finding). Urologic manifestations were diverse with 9 distinct diagnoses involving 6 unique organs. Renal, vesical and scrotal pathologies were most common. Hematuria was the most common presenting symptom in 30% (3/10). Previously unreported findings (labial swelling, renal lymphatic cysts) were identified. The average age of KTS diagnosis was 4.9 years. The average age of documented GU complication and involvement was 7.6 years.

CONCLUSION

Significant GU complications due to KTS can occur in the pediatric population. Early clinical and imaging characterization of these conditions is important for management, family education and early intervention strategies.

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.