13-year-old female patient with recurrent painful swelling at the medial distal left thigh. Condition after surgical exploration, which was aborted due to severe bleeding. Histologically a "hemangioma" was diagnosed. However, this diagnosis does not correspond to the biological behavior of the lesion. Postoperatively no improvement of the exercise-dependent pain.
Digital subtraction angiography (DSA) in the early arterial phase shows a dilated feeding artery (so-called “feeder artery”), in this case a medial superior genicular artery. This artery is dilated over time due to chronic hyperperfusion with increased blood flow.
Digital subtraction angiography (DSA) in the interstitial and early venous phase again 4 s later shows no direct early venous outflow of the contrast agent but, instead, a pooling phenomenon. In an arteriovenous malformation, an immediate venous outflow would be seen because of multiple direct arteriovenous communications.
Super-selective catheterization of the feeding artery with a microcatheter again depicts multiple, fine arteriovenous fistulas, but not the immediate venous outflow as would be typical of an AVM. However, the visible arteriovenous fistulas are unusually prominent in this venous malformation.
The completely occluded venous malformation, which in this case had contained multiple arteriovenous fistulas, was successfully resected after successful embolization and sclerotherapy with complete occlusion. Axial T2-weighted MRI demonstrates the completeness of the resection without a remaining lesion.
The venous malformation (VM) presented with severe intraoperative bleeding during an initial incomplete open resection attempt. On further evaluation, MR angiography revealed multiple atypical arteriovenous fistulas in the venous malformation, but not the typical behavior of an AVM with immediate venous outflow.
The venous malformation was therefore completely embolized from a transarterial access, which is normally not necessary in a venous malformation.
As an added complication, a clear communication with the deep conducting venous system of the leg was found, which had to be occluded before sclerotherapy, in this case with ethanol gel. Subsequently, complete sclerotherapy was performed.
The occluded venous malformation was then completely resected without complications or increased bleeding. The venous malformation has remained asymptomatic to date, and recurrence is not expected.
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