[Paraspinal approach to lumbar foraminal tumor]

To treat lumbar foraminal tumors, the chosen operative approach depends on the tumor location and size. Although total facetectomy and the combined intra- and extraspinal canal approach provide a wide operative field, facet fusion is required and the procedure is invasive. We report the successful removal of Eden type IV tumors using only the paraspinal approach without complete facetectomy.

We treated 4 patients with lumbar foraminal tumors. All were Eden type IV (neurofibroma, n=3; schwannoma, n=1) and all were removed via the paraspinal approach without total facetectomy and the intraspinal canal approach. Although total facetectomy was not needed to remove the intraforaminal component, phased foraminal expansion with a SONOPET (m&m Co., Ltd., Tokyo, Japan) device was required in all cases. Intratumoral decompression was performed with probe for tumor and PAL-I and EMG recordings were obtained with direct stimulation of the nerve root.

All tumors were completely removed via only the paraspinal approach; neither total facetectomy and fusion, nor the addional intraspinal approach was required. There was no tumor recurrence or lumbar instability during the follow-up period.

To remove the intraforaminal component of Eden type IV tumors, phased expansion of the foramen with a SONOPET and intratumoral decompression with CUSA and PAL-I are required and effective. Using these devices, this less invasive approach is useful for the treatment of patients with lumbar foraminal tumors of Eden type IV.