TOTAL EN-BLOC SPONDYLECTOMY AND CIRCUMSPINAL DECOMPRESSION FOR SOLITARY SPINAL METASTASIS

We have developed a new surgical technique, 'total en bloc spondylecto my' (TES), to treat a solitary metastasis in the thoracic or lumbar ve rtebra. This operation is designed as a local cure for the metastatic site and involves the radical resection of the affected vertebra with a wide margin. The spondylectomy consists of two steps: en bloc lamine ctomy with posterior spinal instruments for stabilisation (first step) and en bloc corporectomy and replacement using a vertebral prosthesis (second step). TES makes it possible to remove the affected vertebra extracompartmentally with its tumour barrier and accomplishes circumfe rential decompression of the spinal cord. Before clinical practice, we constructed experimental models using cats to examine spinal cord blo od flow (SCBF) after ligation of the nerve roots and circumspinal deco mpression. The changes of SCBF were negligible, so it was proved that TES on one vertebra has little effect on spinal cord circulation. This method was used in 24 patients. Fourteen of the 18 patients with neur ological deficits improved remarkably, and the 23 evaluable cases expe rienced pain relief. Impending paralysis was prevented in all six pati ents by this surgical intervention. There has been no recurrence of th e local tumour after surgery. After a median follow up period of 14.1 months, 12 patients have survived. These data suggest that TES may hav e a significant clinical value in the treatment of spinal metastasis.