Efficacy of Biportal Endoscopic Spine Surgery for Lumbar Spinal Stenosis

BACKGROUND: Biportal endoscopic spine surgery (BESS) is a recent addition to minimally invasive spine surgery treatments. It boasts excellent magnification and fine discrimination of neural structures. Selective decompression with preservation of facet joints for structural stability is also feasible owing to access to the spinal canal and foramen deeper inside. This study has a purpose to investigate clinical benefits of BESS for spinal stenosis in comparison to the other common surgical treatments such as microscopic decompression-only (DO) and fusion and instrumentation (FI). METHODS: From December 2013 to March 2015, 30 cases of DO, 48 cases of FI, and 66 consecutive cases of BESS for lumbar spinal stenosis (LSS) were enrolled to evaluate the relative clinical efficacy of BESS. Visual analog scale (VAS) for back pain and leg pain, postoperative hemoglobin, C-reactive protein (CRP) changes, transfusion, and postoperative complications were examined. RESULTS: All the patients were followed up until 6 months, and 98 patients (86.7%) for 2 years. At the 6-month follow-up, VAS for back pain improved from 6.8 to 2.8, 6.8 to 3.2, and 6.8 to 2.8 (p = 0.078) for BESS, DO, and FI, respectively; VAS for leg pain improved from 6.3 to 2.2, 7.0 to 2.5, and 7.2 to 2.5 (p = 0.291), respectively. Two cases in the BESS group underwent additional foraminal decompression, but no fusion surgery was performed. Postoperative hemoglobin changes for BESS, DO, and FI were −2.5, −2.4, and −1.3 mL, respectively. The BESS group had no transfusion cases, whereas 10 cases (33.3%) in DO and 41 cases (85.4%) in FI had transfusion (p = 0.000). CRP changes for BESS, DO, and FI were 0.32, 6.53, and 6.00, respectively, at day 2 postoperatively (p = 0.000); the complication rate for each group was 8.6% (two dural tears and one root injury), 6.7% (two dural tears), and 8.3% (two dural tears and two wound infections), respectively. CONCLUSIONS: BESS for LSS showed clinical results not inferior to those of the other open surgery methods in the short-term. Stable hemodynamic changes with no need for blood transfusion and minimal changes in CRP were thought to cause less injury to the back muscles with minimal bleeding. Foraminal stenosis decompression should be simultaneously conducted with central decompression to avoid an additional surgery.