Transforaminal Full-endoscopic Discectomy for Gas-containing Herniated Nucleus Pulposus at L5-S1 Under Local Anesthesia : A Case Report.

The vacuum phenomenon is often observed in degenerative disc disease, whereas gas-containing disc herniation is relatively rare. Full-endoscopic discectomy at the lumbar spine level via a transforaminal approach, which was established and subsequently refined over the last two decades, requires only an 8-mm skin incision and causes minimal damage to the paravertebral muscles. Foraminoplasty, performed with a high-speed drill, is a useful technique to enlarge the foramen, especially when applied at the L5-S1 level, where the trajectory is limited because of anatomical structures such as the iliac crest. Here, we report a case of gas-containing lumbar disc herniation at L5-S1 that was successfully treated by transforaminal full-endoscopic discectomy. The patient was a 62-year-old man with low back pain and pain in the plantar aspect of the right great toe. Magnetic resonance and computed tomography scans demonstrated gas-containing lumbar disc herniation at L5-S1 on the right. Following foraminoplasty, transforaminal full-endoscopic lumbar discectomy was successfully performed under local anesthesia. The patient's symptoms improved immediately after the surgery. Transforaminal full-endoscopic surgery can be effective and minimally invasive even when performed for gas-containing disc herniation. J. Med. Invest. 69 : 328-331, August, 2022.