Prenatal Diagnosis of Vascular Anomalies: Update and Review of the Literature

Sirolimus used for treatment of retroperitoneal arteriovenous malformation in a premature neonate

We describe a case of a premature infant with antenatally detected retroperitoneal arteriovenous malformation (AVM) with extensive intraspinal extension. Treatment of the malformation with embolectomy and sclerotherapy was not feasible in view of intraspinal extensions and small size of vessels of the lesion. During a trial of propranolol over 20 days, the lesion progressed in size, roughly doubling in volume and was accompanied with deranged coagulation parameters. Treatment was therefore switched to oral prednisolone and sirolimus. The steroid was stopped after 6 weeks and sirolimus was continued with serum drug level monitoring and serial imaging of the malformation. After 4 months of sirolimus, the AVM remained at the same size as at the start of treatment, thus we propose that the drug may have arrested the growth of the lesion. This case highlights the use of sirolimus in management of AVMs in infants.

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.

Rapidly involuting congenital hemangioma: a case of complete prenatal involution

We report a case of rapidly involuting congenital hemangioma of the flank, which was diagnosed in the 2(nd) trimester of gestation and showed complete involution before term. In our case sonography revealed a highly vascular soft tissue mass with smooth contours, which was isointense with the placenta on T2-weighted MR images. The fetus was born with scar tissue at the site of the lesion. To our knowledge this is the 1(st) reported case of rapidly involuting congenital hemangioma showing complete involution before term.

Basic science and clinical aspects of vascular anomalies

PURPOSE OF REVIEW

Patients with vascular and lymphatic anomalies are often 'medical orphans' ascertained through distinct medical specialists. Multidisciplinary vascular anomalies programs provide focused expertise in diagnosis and treatment for patients. National and international workshops on vascular anomalies are fostering clinical and basic science research to enhance our understanding of vascular development and vascular anomalies. Herewith is presented an update of recent advances in the study of vascular/lymphatic anomalies.

RECENT FINDINGS

New original findings include (1) the identification of distinct cell surface markers and other cellular properties in hemangiomas and vascular malformations relevant to vascular development, (2) the discovery of novel genetic mutations and susceptibility genes in patients with vascular anomalies, (3) recognition of new risk stratifications and clinical issues for patients with hemangiomas and vascular malformations, and (4) the elucidation of sequelae from the disorders as well as side effects of recent and previous therapies for vascular anomalies.

SUMMARY

Vascular anomalies are an attractive model for the study of human disorders of vasculogenesis and angiogenesis. The etiology of these disorders is unclear and likely represents a multifactorial process. Clinical clues are leading to scientific investigations that may enable targeted therapies, prevention strategies, or both.

Transiently Arterialized Hemangiomas: Relevant Clinical and Cardiac Issues

Although the majority of hemangiomas of infancy undergo an uncomplicated, predictable course of proliferation followed by involution, a subset of patients sustain a more fastidious course. These include hemangiomas that, at least during part of their life cycle, have a high flow (arterial) component. Hemangiomas with high flow are most frequently located in the liver. These lesions can lead to significant morbidity, with high output cardiac failure. We have identified nonhepatic hemangiomas that have an apparent propensity to develop a high flow element--the parotid, upper arm, scalp, and rarely the upper lip--and present our experience in this report. These lesions appear to behave as transiently "arterialized" hemangiomas.