Comparative study on the technique and efficacy of microscope-assisted MI-TLIF and naked-eye MI-TLIF in lumbar revision surgery

Background: Lumbar revision surgery can be performed by simple lumbar nerve decompression or lumbar interbody fusion, including percutaneous endoscopic lumbar discectomy, transforaminal lumbar interbody fusion (TLIF), etc. However, lumbar revision surgery is very difficult in surgical operation. We sought to explore the technique safety and efficacy of microscope-assisted minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) in lumbar revision surgery.

Methods: Cases of postoperative recurrence following lumbar spine surgery (n = 63) treated from December 2016 to July 2021 were retrospectively analyzed, including 24 cases of microscope-assisted MI-TLIF (microscopic group) and 39 cases of naked-eye MI-TLIF (naked-eye group). The operation time, intraoperative blood loss, incision length, postoperative drainage, length of hospital stay, initial operation, and visual analog score (VAS) of low back and leg pain before and at 7 days and 3 months after the operation and the last follow-up were compared between the two groups. The Oswestry Dysfunction Index (ODI) and the Japanese Orthopaedic Association (JOA) scores before and after the operation and the Bridwell interbody fusion grades at 1 year were compared. The independent t tests, Mann-Whitney U tests, and Chi-square tests were used for analysis.

Results: All 63 patients were successfully treated by operation and were followed up for an average of 31.5 ± 8.6 months (range 12-48 months). The two groups had no significant difference in sex, age, incision length, initial operation, or operative segment (P > 0.05). There was no significance in operation time, VAS score, ODI score, and JOA score of low back pain or Bridwell interbody fusion grade between the two groups (P > 0.05). Significant differences in intraoperative blood loss, postoperative drainage, and the lengths of hospital stay were observed between the two groups (P < 0.05). Cerebrospinal fluid leakage (n = 2), edema of nerve roots (n = 2), and incision infection (n = 1) were observed in the naked-eye group. There were no complications in the microscopic group, such as cerebrospinal fluid leakage, edema of nerve roots, and incision infection.

Conclusion: Although microscope-assisted MI-TLIF and naked-eye MI-TLIF are both effective during lumbar revision surgery, microscope-assisted MI-TLIF brings less trauma, less bleeding, shorter postoperative hospital stay, and faster recovery. Unlike traditional surgery, microscope-assisted MI-TLIF provides a clear visual field, adequate hemostasis, and nerve decompression.