Sclerotherapy for Treatment of Anuerysmal Bone Cysts

Aneurysmal bone cysts (ABCs) are benign expansile lytic bone lesions of unknown origin that occur in the pediatric population. Characteristics of ABCs were previously discussed here.

Typically, the treatment of ABCs involves resection and curettage with or without bone grafting. However, there is a high recurrence rate reported with this treatment method with some studies reporting up to a recurrence rate of greater than 50%.

Surgical resection of ABCs is less favored as an extensive resection may be necessary and may immobilize the patient for a prolonged period. Furthermore, as ABCs are highly vascular lesions, surgical procedures carry the risk of significant blood loss.

Radiotherapy was previously used to treat ABCs but has since been abandoned due to studies demonstrating malignant transformation of the lesions and development of secondary tumors.

The traditional interventional radiology technique of embolization has been used effectively in the treatment of some ABCs. Preoperative selective embolization of the feeding vessel is used to reduce intraoperative blood loss as well as to treat lesions that are surgically inaccessible. Challenges of this therapy include risk of particle embolization to the vertebrobasilar and spinal arterial systems resulting in ischemia to vital structures. Additionally, not all ABCs have a feeding vessel that can be selectively embolized. 

More recently, studies have shown intralesional sclerotherapy to be an effective treatment for ABCs. Sclerosing agents act by damaging the endothelial lining which leads to activation of the coagulation cascade and thrombotic vascular occlusion. Agents that have been used for sclerotherapy include ethanol based solutions, methylprednisone, calcitonin, and doxycycline. Patients usually require several injections of the agent. Post procedure imaging typically shows sclerosis of the lesion with long term complete ossification. Patients have reported a relief of symptoms and low recurrence rates have been reported. This data suggests that image guided sclerotherapy of ABCs may be a safe, minimally invasive method of treating these lesions. 



REFERENCES
Rai AT and Collins JJ. Percutaneous treatment of pediatric aneurysmal bone cyst at C1: a minimally invasive alternative: a case report. AJNR Am J Neuroradiol 2005;26:30-3.
Rastogi S, Varshney MK, Trikha V, et al. Treatment of aneurysmal bone cysts with percutaneous sclerotherapy using polidocanol. J Bone Joint Surg [Br] 2006;88-B:1212-6.