Application and Previous Report of External Channel Positioning System in Enlarged Foraminoplasty

Transforaminal total endoscopic lumbar discectomy (TELD) is a typical minimally invasive procedure that has been successfully used in patients with different types of lumbar disc herniation in recent years. However, the procedure has a steep learning curve. External channel positioning system changes the blind technique of traditional foraminoplasty, which relies on fluoroscopy for repeated evaluation, and makes it a new technique that relies on mechanical operation and objective evaluation, thereby improving safety and reducing learning curve. The application is now reported. Objective: To explore the impact of external channel location system (ECLS) for the improvement of intraoperative parameters and surgical outcomes of foraminal enlargement plasty (FEP) in patients with lumbar disc herniation (LDH). Methods: This prospective case series study enrolled patients with LDH who scheduled for FEP in the Affiliated Hospital of Chengde Medical College between February 2021 and February 2022. The intraoperative parameters and surgical outcomes included nerve root and dural injury, puncture localization and postoperative and preoperative pain (visual analog scale, VAS, and Oswestry disability index, ODI). Results: Eighteen patients were enrolled for analysis. None showed nerve root and dural injury after 3 months, and without recurrence reported. There were 17 (94.4%) patients had a successful puncture localization in one procedure. No significant difference between percent (P) 25 and P75 values of the duration of puncture localization, number of X-ray sessions required for puncture localization, and the duration of operation were observed (all P > 0.05). Postoperative VAS (1.45 ± 0.99 and 6.65 ± 2.08) and ODI (0.13 ± 0.06 and 0.73 ± 0.07) scores were significantly decreased compared with preoperative values (P < 0.05). According to the modified Macnab criteria, 8 and 10 cases had excellent and good outcomes, respectively. Conclusion: ECLS might have favorable improvement for intraoperative parameters and outcomes of FEP.