Interventional Spine

Nikdokht, Farid, M.D.
Matthew, T, Whitehead, M.D., Non ASSR Member
R Sean, Pakbaz, M.D., Non ASSR Member

Excerpta

We present a case of a 53 year old female with multiple myeloma who presented to the Interventional Neuroradiology Suite for treatment of multiple vertebral compression fractures.

The patient was treated on two separate occasions with kyphoplasty at multiple levels in the thoracic and lumbar spine. On her second visit, the patient was treated at the L1, L2, and L4 levels using the new KYPHON cement delivery system (from Medtronic) and a left transpedicular approach at all three levels.

Due to the greater power of this hydraulic delivery system, the device is able to deliver more viscous cement material than the traditional kyphoplasty systems. Therefore, by the time the cement delivery system was detached from the bone filling device, the cement was hardened into a cast which extended from the main methyl methacrylate mass through the pedicle and into the neck of the cannula.

We then allowed time for further hardening of the methyl methacrylate to a more brittle consistency. In order to remove the portion of the methyl methacrylate cast outside the vertebra, we partially pulled out the guide stopping just superficial to the pedicle and leaving it within the paravertebral muscle. We then angled the guide inferiorly to an approximately 45 degree angle while exerting forward pressure at the junction of the guide and skin surface in order to create a fulcrum, thereby transecting the hardened methyl methacrylate cast at the tip of the guide. Finally, we attached a 60 mL syringe to the guide and removed it while exerting maximum suction, to ensure that the methyl methacrylate cast remained within the guide during removal.

This unique rescue technique allowed us to avoid much more invasive measures for removal of the hardened extra-vertebral methyl methacrylate cast which could have required open surgery with dissection of subcutaneous tissues, fascia, and muscles.