Neurological safety of spinal surgery for nucleus pulposus removal under spinal endoscopic imaging guided by inter laminar spine

OBJECTIVE: To explore the technical points, approach selection and short-term clinical efficacy of PELD through the intervertebral foramina or interlaminar approach in the treatment of highly shifted LDH. METHODS: From September 2018 to June 2020, 19 patients with highly shifted LDH were treated with PELD in The First Hospital of Yulin. It included, 10 males and 9 females; aged 34 to 69 years, with an average of 48 years. Thirteen cases were shifted to the caudal side, and six cases were shifted to the head side. The responsible segments included L3/41 cases, L4/511 cases, and L5/S17 cases. All patients had symptoms of low back and leg pain. The Sowerby dysfunction index (ODI) was 63.5%±10.7% before surgery. The visual analogue scale of pain (VAS) was low back pain (5.2±2.1) and leg pain (7.1±2.4). 14 cases used transforaminal approach, and 5 cases used translaminar approach. RESULTS: All cases completed the operation successfully, the operation time was 60~110min, with an average of 70 minutes. The follow-up time ranged from 6 to 42 months, with an average of 20.8 months. At the last follow-up, ODI was 10.8%±6.8%, VAS back pain score (2.1±1.1) and leg pain score (1.8±0.9). Compared with preoperative, ODI and VAS scores were significantly decreased (P<0.05). The results of Mac Nab method were 14 excellent, four good, and one fair. During the follow-up period, one patient’s leg pain symptoms recurred seven days after operation. No further hernia was found under intervertebral foramen. The symptoms disappeared after two weeks of symptomatic treatment such as swelling and analgesia, and he was discharged. No perioperative complications such as infection and nerve root injury occurred. CONCLUSION: When PELD is used to treat high-displacement LDH, the choice of transforaminal approach or interlaminar approach needs to be personalized according to the LDH segment and the direction of displacement.