Intraoperative spinal sonography of soft-tissue masses of the spinal cord and spinal canal.

Intraoperative spinal sonography (IOSS) was used to evaluate and monitor the progress of surgery in 18 patients with soft-tissue masses of the spinal canal and spinal cord. With intramedullary masses, IOSS showed not only the site of maximum cord enlargement so that a precise biopsy could be performed but also was able to demonstrate the zone of transition between the mass and normal cord tissue. With extradural masses and intradural extramedullary masses, IOSS showed the exact size and location of the masses and confirmed their removal and/or adequate spinal cord decompression. IOSS indicated the extent of bone removal necessary to give adequate exposure to accomplish total removal of these masses or to localize the proper level for tissue biopsy. IOSS also indicated the need to open the dura when there had been unsuspected transdural tumor spread or when bony decompression had not been sufficient to relieve the pressure on the spinal cord in tonsillar ectopia. Intraoperative spinal sonography is recommended in all cases of spinal surgery performed to resect or biopsy soft-tissue masses of the spinal canal or spinal cord.