Minimal access spinal surgery (MASS) in treating thoracic spine metastasis

Study Design. A retrospective study was conducted. Objective. This study aims to analyze the feasibility and efficacy of using minimal access spinal surgery ( MASS) for managing thoracic spine metastasis. Summary of Background Data. Literature regarding minimally invasive surgical treatment for thoracic spine metastasis is sparse. In the past decade, the role of minimally invasive or endoscopic technique in managing metastatic thoracic disease has evolved. Methods. From February 1997 to March 2003, 46 patients with spine metastases, from T3 - T12, were enrolled in this study. There were 29 patients undergoing MASS. Seventeen patients received standard thoracotomy ( ST) in the early study period served as the control group. The indications for MASS include intractable back pain and/ or neurologic deficits or neurologic deterioration during or after radiotherapy. Inclusion criteria for this study included tumor limited to one or two vertebral segments. Results. In the MASS and ST groups, no patient died as a result of an immediate intraoperative event. The mean operative blood loss was 1,110 versus 1,162 mL ( P = 0.63), and the mean operative length was 179 versus 180 minutes ( P = 0.54). Complication rates and 1-year, 2-year, and overall survival rates were comparable and the mean grade of neurologic recovery was 1.2 on the Frankel scale in both groups. Only 6.9% of MASS patients required a 2-day postoperative ICU stay compared with 88% of ST patients ( P < 0.0001). Conclusions. The MASS technique is safe and effective and has proved to be an excellent alternative in managing thoracic spine metastasis. Surgeons may use progressively smaller incisions ( 5 - 6 cm in length) for the procedure. The learning curve for performing MASS procedures was not steep.