Abstract: BACKGROUND: Spinal canal decompression using uniportal endoscopic surgery is a new minimally invasive surgery in the treatment of lumbar spinal stenosis. However, this technique needs a steep learning curve and high requirements for surgical equipment and instruments, which limits its clinical application. We previously use the spinal endoscopy as a monitoring endoscopy and combined with unilateral biportal endoscopy to propose a hybrid technique of spinal endoscopy to achieve coaxial endoscopic operation and hands-separate operation.
OBJECTIVE: To compare the clinical outcome of hybrid technique and uniportal endoscopic surgery in treatment of lumbar spinal stenosis with bilateral lower limb pain symptoms. 
METHODS: Ninety patients diagnosed of lumbar spinal stenosis with bilateral symptoms were included and retrospectively analyzed at First People’s Hospital, Shanghai Jiao Tong University from August 2020 to August 2022. 44 cases were included in group A (hybrid technique group), while 46 cases were included in group B (uniportal endoscopic surgery). The nerve decompression was observed during the surgery. Operation time, hospital stay time, and expenses were recorded in both groups. The visual analog scale scores of lower back pain and both lower extremities pain, Oswestry disability index scores of quality of life and excellent and good rate of modified Macnab criteria were recorded and compared at preoperative, postoperative 3 days, and postoperative 3 and 6 months. 
RESULTS AND CONCLUSION: (1) The operation time of group A was significantly shorter than that of group B (P < 0.05). (2) The lower back pain and lower extremity pain of the severe side at postoperative 3 days, and 3 and 6 months were significantly relieved in both groups (P < 0.05). The visual analog scale score of lower extremity pain on the mild side was significantly decreased at postoperative 3 days, 3 and 6 months than preoperative score in the group A (P < 0.05). The visual analog scale score of lower extremity pain on the mild side was significantly decreased at postoperative 3 days than preoperative score in the group B (P < 0.05). The visual analog scale scores of lower extremity pain on the mild side at postoperative 3 and 6 months did not show significant difference than preoperative score in the group B. The comparison between the two groups showed that there was no significant difference in the visual analog scale scores of postoperative lower back pain and lower extremity pain of the severe side (P > 0.05). The visual analog scale scores of lower extremity pain on the mild side in the group A were significantly lower than those of group B at postoperative 3 and 6 months (P < 0.05). (3) The Oswestry disability index scores of both groups at postoperative 3 day were significantly lower than preoperative score (P < 0.05), and there was no significant difference between the two groups 3 days after operation. Oswestry disability index scores of group A at postoperative 3 and 6 months were significantly decreased than preoperative score (P < 0.05). The Oswestry disability index scores of group B at postoperative 3 and 6 months did not show significant differences than preoperative score (P > 0.05). The comparison between the two groups showed the Oswestry disability index scores of group A were significantly lower than group B at postoperative 3 and 6 months (P < 0.05). (4) The results of modified Macnab showed that the excellent and good rate of group A was significantly higher than that of group B (95%, 78%, P < 0.05). (5) It is indicated that the hybrid technique is a new spinal endoscopy technique, which has the advantages of less trauma and faster recovery as a minimally invasive surgery. The clinical outcome of hybrid technique is superior to that of uniportal endoscopic surgery in the treatment of lumbar spinal stenosis with bilateral symptoms. Additionally, it also has the advantages of good operational flexibility and high decompression efficiency as an open surgery. 

Key words: spine endoscopy hybrid technique, uniportal endoscopic surgery, lumbar spinal stenosis, bilateral symptom, decompression