Spinal Kaposiform Hemangioendotheliomas: Is There a Role for Endovascular Treatment?

Abstract

Kaposiform hemangioendotheliomas (KHE) are rare vascular neoplasms composed of groups of capillaries and endothelial cells, forming aneurysms and arteriovenous fistulas. They occur mainly in the extremities during early childhood or infancy, and although they are locally aggressive, the occurrence of metastases is uncommon. A 9-month-old male infant born with a thoracolumbar cutaneous red lesion presented with progressive loss of strength in lower limbs, evolving with progressive flaccid paraplegia and areflexia. The investigation showed extensive intramedullary injury extending from T2 to L2, with associated intradural aneurysms. After an excisional biopsy showing KHE, the intradural lesion was treated endovascularly through transarterial embolization using PVA microspheres2. The uneventful procedure was complemented by corticosteroids and systemic chemotherapy with vincristine, achieving rapid and progressive motor recovery. After 6-months of follow-up, the patient was able to walk with ataxic gait and imaging showed remission of the lesion.KHE generally affect the trunk, retroperitoneum and extremities, but cases involving the head and neck were already described. Complication with Kasabach-Merritt syndrome (KMS) is common, and it is characterized by life-threatening thrombocytopenia, hemolytic anemia, and coagulopathy. Due to tumor rarity, delayed diagnosis is frequent. The lesions should be preoperatively distinguished from benign lesions, such as infantile hemangioma, because imaging characteristics are different. The optimal therapy is still unknown, and although complete surgical excision is considered curative, extensive intramedullary injuries may be difficult to resect due to the risk of hemorrhage. The endovascular treatment of vascular spinal lesions has potential to reduce the intraoperative bleeding, shrink the lesion and avoid mass effect. However, the feeding arteries of KHE are usually numerous and thin, thus embolization may be difficult. The targeted therapy with the mTOR inhibitor (such as sirolimus and everolimus) may have better results than traditional vincristine, and adjunct embolization seems to induce faster resolution of KMS. Endovascular treatment is a valuable tool to improve outcomes and quality of life, therefore multidisciplinary treatment is encouraged.