[Application of intraoperative spinal ultrasonography in thoracic spinal decompressive operations]

To investigate the feasibility and clinical value of intraoperative ultrasonography (IOUS) in thoracic spinal decompression surgery.

Ten patients with confirmed thoracic spinal stenosis underwent thoracic spinal decompression in our center from August 2009 to December 2010. The appearance of the compressed section of spinal cord was observed with IOUS. Before and after the decompression operation, the diameters of dural sac and the spinal cord were recorded respectively. The location and nature of the compression-causing mass were confirmed.

IOUS clearly showed the shape of the normal and the compressed sections of dural sac and spinal cord. In the 14 thoracic spinal cord sections of these 10 patients, the anteroposterior diameter, horizontal diameter, and their ratio were bigger than those before decompression. The values of anteroposterior diameter and anteroposterior/horizontal diameter ratio showed significant differences(the P value of dural sac anteroposterior diameter comparison was 0.008, which of spinal cord was 0.007; the P values of these two structures ratio comparison were both 0.002 before and after decompression), while the horizontal diameter presented no significant differences (the P values of both structures were 0.270 and 0.195 respectively before and after decompression).

IOUS can clearly show the morphological changes of the dural sac and spinal cord before and after the decompression. In addition, it helps surgeons to locate and specify the nature of the compression-causing mass on the ventral side of dural sac. Furthermore, IOUS can suggest whether the decompression is sufficient in a real-time manner.