Venous Malformations and Blood Coagulation in Children

Assessing coagulopathy and endothelial dysfunction in pediatric venous malformation: A thromboelastometry and syndecan-1 study

OBJECTIVE

The occurrence of unpredictable pain crises are the principal determinant of the quality of life for patients with venous malformations (VM). A definite coagulation phenomenon, characterized by an increase in D-dimer levels and the presence of phleboliths within the malformation, has been previously reported. By applying Virchow's triad and evaluating intralesional samples, our objective is to delineate the coagulation profile and the extent of endothelial dysfunction within the malformation.

METHODS

With the authorization of the Ethics Committee, a research project was undertaken on intralesional and extralesional blood samples from 30 pediatric patients afflicted with spongiform VM. Thromboelastometry analyses were performed using ROTEM Sigma, and the concentration of syndecan-1 was determined by ELISA.

RESULTS

In the ROTEM analyses, the A5, A10, and maximum clot firmness (MCF) values were below the established reference ranges in the intralesional samples in both the EXTEM and INTEM assays, indicating that intralesional clots had significant instability. Furthermore, during the investigation of the delayed fibrinolysis phase using recombinant tissue plasminogen activator (rtPA) in EXTEM analysis, widespread hyperfibrinolysis was observed intralesional. Additionally, analysis of syndecan-1 showed significant differences between extralesional and intralesional levels (p < .026) and controls (p < .03), suggesting differences in the state of endothelium.

CONCLUSIONS

For the first time, we developed a comprehensive understanding of the coagulopathic profile of VM and the role of endothelial dysfunction in its pathogenesis. These findings will enable the implementation of targeted therapies based on the individual coagulation profiles.

Imaging of peripheral vascular malformations - current concepts and future perspectives

Vascular Malformations belong to the spectrum of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic vasculature. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) is of major importance to guide proper treatment. Imaging plays a crucial role to classify vascular malformations according to their dominant vessel type, anatomical extension, and flow pattern. Several imaging concepts including color-coded Duplex ultrasound/contrast-enhanced ultrasound (CDUS/CEUS), 4D computed tomography angiography (CTA), magnetic resonance imaging (MRI) including dynamic contrast-enhanced MR-angiography (DCE-MRA), and conventional arterial and venous angiography are established in the current clinical routine. Besides the very heterogenous phenotypes of vascular malformations, molecular and genetic profiling has recently offered an advanced understanding of the pathogenesis and progression of these lesions. As distinct molecular subtypes may be suitable for targeted therapies, capturing certain patterns by means of molecular imaging could enhance non-invasive diagnostics of vascular malformations. This review provides an overview of subtype-specific imaging and established imaging modalities, as well as future perspectives of novel functional and molecular imaging approaches. We highlight recent pioneering imaging studies including thermography, positron emission tomography (PET), and multispectral optoacoustic tomography (MSOT), which have successfully targeted specific biomarkers of vascular malformations.

Blue rubber bleb nevus syndrome: a single-center case series in 12 years

BACKGROUND

Blue rubber bleb nevus syndrome is a rare congenital disease characterized by multiple venous malformations in skin and gastrointestinal tract, not all patients have typical cutaneous lesions, refractory anemia may be the only clinical symptom, it is easy to miss diagnosis.

METHODS

A retrospective single center study was conducted on 8 patients with blue rubber bleb nevus syndrome from 2009 to 2021. Data were analyzed including clinical feature, diagnostic workup and results, gene detection, treatment and follow-up.

RESULTS

Five children (62.5%) developed the disease in infancy, which initial symptoms were all cutaneous venous malformations. All children had chronic refractory anemia and gastrointestinal bleeding. Cutaneous lesions were observed in 87.5%, 1 child had multiorgan involvement. Gastrointestinal venous malformations were observed in 100%, lesions were more common in small intestine than in stomach or colon. No somatic mutation in TEK was found in our children. Diagnostic interval was on average 4.7 years. Eighty-seven-point-five percent children received at least one endoscopic or surgical intervention, however, those methods could not eradicate all the lesions and prevent relapse. Two children treated with sirolimus for more than 8 years, only 1 have satisfactory therapeutic effect. Besides, I child has growth retardation and emotional problems during follow-up.

CONCLUSIONS

Blue rubber bleb nevus syndrome needs to be considered when find bluish nodular cutaneous lesions, chronic anemia or gastrointestinal bleeding of unknown origin. Capsule endoscopy is the most sensitive in diagnosing of this disease. Oral sirolimus at a relatively low dosage is effective, further comprehensively studies are required to evaluation of its efficacy, safety and the optimal dosage about the children.