Minimally Neural Retractive, Total Annular Resection, Transforaminal Endoscopic (TARTE) Approach for Severely Canal Compromising Lumbar Disk Herniation Accompanied by a Neurologic Deficit

Abstract

Objective Treatment of severely canal compromising lumbar disk herniations (LDH), occupying more than 50% of the canal area, are associated with technical difficulty and worse outcomes. This study aimed to describe new techniques of transforaminal endoscopic lumbar diskectomy (TELD) with less neural retraction, and total annular resection for broad-based severely canal compromising disk herniation. We also evaluated the feasibility and safety of the techniques, and analyzed the clinical and radiologic outcomes of 32 patients presenting with neurologic deficits. Methods A retrospective cohort study was performed with 32 consecutive patients who underwent TELD for broad-based severely canal compromising LDH between January 2018 and January 2020. We removed the LDH using two novel techniques: (1) the “mobile outside-in” approach and total annular resection method and (2) internal decompression and subsequent pushdown method of the migrated fragment. The cross-sectional area (CSA) on magnetic resonance image was evaluated preoperatively and compared with the postoperative image within 7 days and between 6 months and 1 year. The visual analog scale (VAS) for back and leg pain, Oswestry disability index (ODI), MacNab's criteria, and motor power of the involved lower extremities were evaluated pre- and postoperatively. Results A total of 32 patients, with an average age of 37.5 years (range: 17–66), underwent surgery. The mean VAS score for back pain improved from 7.84 ± 1.02 to 1.31 ± 0.54 and the ODI score improved from 74.3 ± 7.82 to 20.4 ± 3.71 at final follow-up. According to MacNab's criteria, 23 patients had excellent and 9 patients had good outcomes at final follow-up. All patients operated on at the L4–L5 level had great toe/ankle dorsiflexion and/or ankle plantar flexion weakness; knee extension weakness was found at the L2–L3 and L3–L4 levels. Motor function improved significantly; the mean values and range preoperatively, and at 1 month, 3 months, and final follow-up, were 3.41 ± 0.95 (1–4), 4.56 ± 0.56 (3–5), 4.88 ± 0.34 (4–5), and 4.97 ± 0.18 (4–5), respectively (p < 0.001, at all follow-up). The mean values and range of the preserved CSA proportion, preoperatively and within 1 week after surgery, and at final follow-up were 34.9 ± 10.9 (15–61), 81.06 ± 10.24 (63–97), and 93.03 ± 5.37 (76–99), respectively (p < 0.001, at all follow-up). Conclusion The transforaminal endoscopic approach for broad-based severely canal compromising LDH can be considered a feasible surgical option for an experienced surgeon. With total annular resection and pushdown of migrated fragments, safe and complete removal of LDH was possible in patients with a neurologic deficit. Total annular resection may increase the overall but not the early recurrence rate.