SLR - August 2014 - Valarie Samoy
Reference: Shisha T, Marton-Szucs G, Dunay M, Pap K, Kiss S, Nemeth T, Szendroi M, Szoke G. The Dangers of Intraosseous Fibrosing Agent Injection in the Treatment of Bone Cysts. The Origin of Major Complications Shown in a Rabbit model. International Orthopaedics. 2007; 31:359-362.
Scientific Literature Review
Reviewed By: Valarie Samoy, DPM
Residency Program: Southern Arizona VA Healthcare System
Podiatric Relevance: Aneurysmal bone cysts (ABC) are benign bony lesions consisting of blood-filled spaces, which most commonly occupy the metaphysis of long bones (i.e. tibia) and the calcaneus. These lesions are commonly treated surgically with curettage and grafting, however, percutaneous procedures such as injection with a fibrosing agent (Ethibloc) have been reported with successful results.
Methods: Twelve New Zealand White Rabbits underwent the same procedure, and an additional three rabbits served as a control group. Prior to injection, each rabbit was administered anesthesia and the left hind limb was shaved. Using a standard needle and sterile surgical technique, the medial cortex of the tibia was punctured and 0.5 ml of intraosseous tissue was aspirated. Approximately 0.5 ml of Ethibloc was slowly injected into the void. In the control group, the 0.5 ml of aspirated tissue was re-administered instead of Ethibloc.
Results: All rabbits not treated with the fibrosing agent (control group) recovered fully and remained healthy throughout follow-up. 9 of 12 (75 percent) rabbits treated with the fibrosing agent died within 3-15 minutes post-injection, and an additional rabbit in the same group died one hour post-injection. The remaining two rabbits recovered fully and remained healthy throughout follow-up. Necropsy was performed, which revealed massive pulmonary embolism in all deceased rabbits. The emboli consisted solely of Ethibloc.
Conclusions: It is believed that Ethibloc may enter systemic circulation through either venous anastomoses or through the wall of the medulla, especially if overdosed. The authors conclude that repeated injection of smaller quantities of Ethibloc may be safer than a single injection of a larger quantity. It is also suggested that mapping of any venous drainage via injection of contrast material be performed prior to injection of a fibrosing agent to assess risk of embolism.