Surgical experience of gas-containing disk herniation.

Disk herniation with gas or gas-containing disk herniation (GCDH) is rare, although epidural gas is associated with the vacuum phenomenon. The clinical, radiologic, and surgical findings were retrospectively analyzed of 18 patients with GCDH. The demographic, clinical, and radiologic findings including computed tomography and magnetic resonance imaging, as well as operative methods were examined. The mean age was 64.4 years (range 51-84 years). All patients presented with acute radiculopathy or exacerbation of chronic pain associated with GCDH of the lumbar spine. All lumbar GCDHs were related to the vacuum phenomenon. Ruptured disks predominantly compressed the nerve root with gas in 17 cases, except in one with only compressed nerve root by gas without disk herniation. All patients had confirmed GCDH at surgery. All patients underwent removal of GCDH and five with another level of spinal stenosis or disk herniation underwent selective decompression. The six patients with instability underwent fusion. Visual analogue scale score of radicular pain was improved from 7.4 ± 0.9 before surgery to 3.2 ± 0.7 at the 3-month follow-up examination. No recurrence occurred after surgery. GCDH can occur as a space-occupying lesion in epidural space as well as a cause of radiculopathy. GCDH may indicate the source of clinical symptoms in the degenerative spine, especially combined with spinal stenosis or multiple spinal disk herniations.