Localized intravascular coagulation in venous malformations: A system review

Vascular Malformations

Vascular malformations are intricate anomalies of the circulatory system, presenting a diverse array of clinical manifestations, and posing significant challenges in diagnosis and treatment. The pathogenesis of vascular malformations is explored through the lens of genetic and molecular mechanisms, shedding light on the pivotal role of somatic mutations and dysregulated signaling pathways. Clinical presentations of vascular malformations are widely variable, ranging from cosmetic concerns to life-threatening complications. The utility of imaging techniques, such as magnetic resonance imaging (MRI), computed tomography (CT), and angiography, are discussed in detail, emphasizing their role in precise delineation and characterization. Therapeutic strategies for vascular malformations are multifaceted, considering factors such as lesion size, location, potential complications, and patient-specific factors. Traditional interventions, including surgical excision and embolization, are appraised alongside emerging approaches like targeted molecular therapies and minimally invasive procedures. The manuscript underscores the need for an individualized treatment approach, optimizing outcomes while minimizing risks and complications. In summation, this manuscript offers a comprehensive analysis of vascular malformations, encompassing their underlying pathogenesis, clinical nuances, diagnostic methods, and therapeutic considerations. By synthesizing current knowledge and highlighting gaps in understanding, this review serves as a valuable resource for clinicians, researchers, and medical practitioners, fostering an enhanced comprehension of vascular malformations and paving the way for improved patient care and innovative research endeavors.

Localised intravascular coagulation complicating venous malformations: Clinical characterisation

OBJECTIVE

The International Union of Phlebology recommends measuring at least D-dimer and fibrinogen levels in the diagnosis of extensive extra-truncular venous malformations, with a surface area of 10 cm2 or those which are deep, as well as prior to any interventional procedure. The aim of the study was to characterise venous malformations associated with a possible vascular complication.

METHOD

This study was an observational and multicentre study. The objective was to explore the presence of a possible coagulation disorder among patients with venous malformation. The primary endpoint was to characterise venous malformations with increased D-dimer levels.

RESULTS

The majority of the 72 venous malformations were located in the trunk region, mostly in intramuscular or subcutaneous locations. There were 72 venous malformations with increased D-dimer levels including 3 with biological disseminated intravascular coagulation (elevated D-dimer and fibrinogen <1 g/L). The anticoagulant treatments administered were very heterogeneous in class and dosage, and at the end of the treatment, 17 elevated D-dimers were persistent, 9 venous malformations remained painful and 27 showed thrombotic regression.

CONCLUSION

Venous vascular malformations are probably underestimated and should probably be explored more systematically in terms of coagulation disorder regardless of size or symptomatology. The therapeutic recommendations to treat localised intravascular coagulation with low-molecular weight are not widely applied. Studies are needed, in particular to assess the role of oral anticoagulants in the management of coagulation disorder among patients with venous malformation.

Study of vascular sclerosing agent based on the dual mechanism of vascular endothelial cell damage-plasmin system inhibition

Venous malformations are a vascular disorder. Currently, the use of chemical sclerosing agents is a common clinical approach for the treatment of venous malformations. However, the effectiveness of existing sclerosing agents is unsatisfactory and often accompanied by severe side effects. In this study, we have developed a novel cationic surfactant-based sclerosing agent (POL-TA) by conjugating the plasmin inhibitor tranexamic acid (TA) with a nonionic surfactant polidocanol (POL) through an ester bond. POL-TA induces endothelial cell damage, triggering the coagulation cascade and thrombus formation. Moreover, it releases TA in vivo, which inhibits plasmin activity and the activation of matrix metalloproteinase (MMPs), thereby stabilizing the fibrin network of the thrombus and promoting vascular fibrosis. We have established a cell model using venous malformation endothelial cells and assessed the cellular damage and underlying mechanisms of POL-TA. The inhibitory effects of POL-TA on the plasmin-MMPs system were evaluated using MMP-9 activity assay kit. Additionally, the mice tail vein model was employed to investigate the vascular sclerosing effects and mechanisms of POL-TA.

Dabigatran etexilate is efficacious in consumptive coagulopathy and pain associated with venous malformations

OBJECTIVE

Consumptive coagulopathy treatment and pain management are crucial for patients with venous malformations (VMs). Dabigatran etexilate, a non-vitamin K antagonist oral anticoagulant, has known advantages compared with low-molecular-weight heparin and vitamin K antagonists, including oral administration, a more consistent pharmacokinetics/pharmacodynamics profile, a better safety profile, and no need for coagulation surveillance. In the present study, we tested the efficacy and safety of dabigatran etexilate for consumptive coagulopathy treatment and pain management for patients with VMs.

METHODS

To investigate the efficacy and safety of dabigatran etexilate in treating localized intravascular coagulation (LIC) associated with VM, we retrospectively collected data for 19 outpatients with VM and LIC, who had been treated with dabigatran etexilate from September 2019 to June 2021. The patients provided oral informed consent and underwent biologic blood testing, routine examinations, and determination of coagulation function before and after treatment. The dosage of dabigatran etexilate was 110 mg twice daily for adults and 55 mg twice daily for children.

RESULTS

All 19 patients had benefited from dabigatran etexilate treatment with coagulation improvement and pain relief. Pain had improved in all 16 evaluable patients. The fibrinogen and D-dimer levels had improved in 18 of 19 patients. The fibrin degradation product level had improved in 10 of 14 patients. None of patients reported lesion regression, appearance changes, or improvement in mobility. No significant differences were found in the D-dimer, fibrinogen, and fibrin degradation product levels between the short-term (<10 days) and long-term (≥10 days) use of the medication. Dabigatran etexilate was well tolerated by all patients. No bleeding event had occurred during follow-up.

CONCLUSIONS

The results of our study have confirmed the efficacy and safety of dabigatran etexilate in treating pain and LIC in patients with VMs. Dabigatran etexilate is a suitable choice preoperatively to modify coagulation function and pain in patients with VMs.

Comprehensive analysis of exosomal circRNA, lncRNA, and mRNA profiles to identify the potential RNAs involved in the pathogenesis of venous malformation

BACKGROUND

Venous malformation (VM) is a kind of congenital vascular anomaly with a high incidence of recurrence, detailed pathogenesis and standard treatment of VM still lack now. Increasing evidence showed exosomal RNA plays a pivotal role in various diseases. However, the underlying mechanism of VM based on the potential differentially exosomal RNAs remains unclear.

METHODS

Comparative high-throughput sequencing with serum exosomes from three VM patients and three healthy donors was used to explore differentially expressed (DE) circRNAs, DE lncRNAs, and DE mRNAs involving the formation of VM. We identified and verified DE circRNAs, DE lncRNAs, and DE mRNAs via qRT-PCR assay. We explored the potential functions of these exosomal DE non-coding RNAs via performing further Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Besides, circRNA/lncRNA-miRNA-mRNA linkages were also constructed to find their potential relationships in VM.

RESULTS

A total of 121 circRNAs, 53 lncRNAs, and 42 mRNAs (|log₂ FC| ≥ 2.0, FDR <0.05, n = 3) were determined to be differentially expressed. QRT-PCR validated that these top-changed DE circRNAs, lncRNAs, and mRNAs had significant expression changes. Functional studies demonstrated that DE circRNAs play a pivotal role in thyroid hormone signaling pathway, DE lncRNAs function as a key regulator in MAPK signaling pathway and DE miRNAs participate in the process of hepatocellular carcinoma mostly.

CONCLUSION

Our study comprehensively depicted exosomal DE non-coding RNAs networks related to the pathogenesis of VM which can provide new insight into, a novel target for treating VM.

Venous Malformations

Venous malformations, the most common type of vascular malformation, are slow-flow lesions resulting from disorganized angiogenesis. The International Society for the Study of Vascular Anomalies (ISSVA) classification offers a categorization scheme for venous malformations based on their genetic landscapes and association with congenital overgrowth syndromes. Venous malformations present as congenital lesions and can have broad physiologic and psychosocial sequelae depending on their size, location, growth trajectory, and tissue involvement. Diagnostic evaluation is centered around clinical examination, imaging evaluation with ultrasound and time-resolved magnetic resonance imaging, and genetic testing for more complex malformations. Interventional radiology has emerged as first-line management of venous malformations through endovascular treatment with embolization, while surgery and targeted molecular therapies offer additional therapeutic options. In this review, an updated overview of the genetics and clinical presentation of venous malformations in conjunction with key aspects of diagnostic imaging and treatment are discussed.

How we approach localized vascular anomalies

Vascular anomalies are a group of disorders divided into two distinct subtypes: vascular tumors and vascular malformations. Vascular tumors are proliferative in nature, while malformations are nonproliferative. Simple, localized vascular malformations refer to a group of malformations that are localized to a single area of involvement. These simple malformations include capillary, lymphatic, venous, and arteriovenous malformations. The pediatric hematologists and oncologists are becoming increasingly involved in the diagnosis and management of these disorders. This review presents four cases as a means to discuss the diagnosis, clinical and imaging features, and management strategies of simple, localized vascular malformations.

Treatment outcomes and effects of ethanol sclerotherapy on systemic coagulation profile of patients with venous malformation

OBJECTIVE

Venous malformations (VMs) and sclerotherapy may disrupt the normal systemic coagulation profile in individuals. This study investigated a correlation between the clinical efficacy of sclerotherapy in the treatment of VMs and the changes in coagulation indexes to provide data that will inform future application of this therapy.

METHODS

From September 2019 to September 2020, 61 patients were enrolled in this study to receive sclerotherapy with absolute alcohol. The clinical outcomes and the coagulation profile were assessed.

RESULTS

Sclerotherapy induced increasing in fibrin (original) degradation products (FDP), D-dimer (D-D). The changes in FDP and D-D level pre- and post-treatment were positively correlated with treatment outcomes. Moreover, repeated treatment with absolute alcohol may restore normal levels of FDP and D-D.

CONCLUSIONS

Upregulation of FDP and D-D levels after sclerotherapy results in good therapeutic outcomes. Therefore, monitoring changes in FDP and D-D levels in patients with VMs undergoing sclerotherapy may reflect the effects of sclerotherapy.

Refractory serositis in Gorham–Stout syndrome

Background

Gorham–Stout syndrome (GSS) is a rare disorder with various presentations and unpredictable prognoses. Previous understandings of GSS mainly focused on progressive bone destruction, while we identified a group of GSS patients with serous effusion as the first symptom. This study aimed to investigate the clinical characteristics of patients with GSS having serous effusion as the first symptom.

Methods

Patients diagnosed with GSS were identified through the Peking Union Medical College Hospital Medical Record System. The demographic, clinical, laboratory, and imaging data were collected. Patients who first presented with serous effusion were recruited into the serous group, while those with bone destruction were recruited into the bone group.

Results

Of the 23 patients with GSS enrolled, 13 were in the bone group and 10 in the serous group. The median disease duration was shorter and exercise tolerance was lower in the serous group. Despite less frequent bone pain in the serous group, the frequency of bone involvement was similar to that in the bone group. Patients in the serous group had higher rates of bilateral pleural effusion and multiple serous effusion. However, serous effusion also developed with disease progression in the bone group. Of the 17 patients treated with bisphosphonates, 14 reached bone-stable state. However, 5 out of 10 patients with serous effusion still had refractory effusions after bisphosphonates treatment. Three patients received sirolimus treatment, with an improvement in serous effusion. Seventeen patients were followed up; three patients died, two in the bone group and one in the serous group.

Conclusions

This study discovered that GSS could first be presented with serous effusion. We believe that this may be a new phenotype of the disease. Sirolimus might help in controlling serous effusion and improving prognosis.

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.