Efficacy of novel minimally invasive surgery using spinal microendoscope for treating extraforaminal stenosis at the lumbosacral junction.

ABSTRACT

STUDY DESIGN: A retrospective case study of the spinal microendoscopic surgery for the treatment of extraforaminal stenosis at the lumbosacral junction. OBJECTIVE: To evaluate the efficacy of a minimally invasive technique using spinal microendoscope and to examine the 2-year surgical outcome for this disease. SUMMARY OF BACKGROUND DATA The paraspinal approach has been the gold standard to expose the extraforaminal space. Although it seems to be ideal, the constricted surgical field of view may compromise the surgeon's ability and increase the risk of complications. This technique can be improved further. METHODS: A total of 32 patients, who completed a minimum follow-up of 2 years after the surgery, were included in this study. The study group consisted of 16 men and 16 women with an average age at surgery of 64 years and a mean follow-up of 37.4 months. Clinical results were evaluated according to the Japanese Orthopaedic Association (JOA) scoring system, visual analog scale, and the North American Spine Society Low Back Outcome Instrument. RESULTS: Two of these patients required revision surgery to correct insufficient decompression in the foramen. In the 30 other patients, the mean JOA score was 15.1 points before surgery and 23.1 points at the final follow-up. The mean recovery rate was 60.1%. The JOA scores improved significantly after surgery and the satisfactory results were maintained until the final follow-up. The visual analog scale scores for low-back pain, leg pain, and numbness also significantly improved. Twenty-eight of 32 patients (87.6%) were satisfied with this procedure. CONCLUSIONS: The spinal microendoscopic surgery demonstrated efficacy for treating extraforaminal stenosis at the lumbosacral junction where the lesion is difficult to be exposed. Quick and easy access along with minimal damage to the back muscles and bony structures could be accomplished using the property of its oblique view and angled surgical equipments. This procedure has produced long-lasting favorable outcomes and high patient satisfaction. Novel minimally invasive surgery may replace conventional open methods.