Prospective comparative analysis of three types of decompressive surgery for lumbar central stenosis: conventional, full-endoscopic, and biportal endoscopic laminectomy

Abstract

Conventional open laminectomy has long been considered one of the important surgical options for lumbar central stenosis owing to its positive outcomes. However, newer approaches have emerged as alternatives, including full-endoscopic and biportal endoscopic laminectomy. Therefore, a comparison of the outcomes that are associated with each of these surgical methods is warranted. This prospective multicenter trial, initiated in February 2019, compared the outcomes of three lumbar central stenosis surgical approaches: open laminectomy (OPEN), uniportal endoscopy (UNIPORT), and biportal endoscopy (BIPORT). Among 115 participants from seven centers, one-year follow-ups assessed laboratory, radiological, and clinical outcomes. Despite all groups showing adequate decompression and clinical improvement, the OPEN group exhibited less improvement in Visual analog scale (VAS) for back pain scores (p < 0.05) and significant postoperative increases in most laboratory markers. Furthermore, the OPEN group experienced a significant decrease in multifidus muscle cross-sectional area compared to endoscopic groups (p < 0.001). Each surgical techniques produced similar clinical outcomes and dural space expansion. However, endoscopic surgery was associated with better muscle preservation and better relief of back pain. Endoscopic surgery is a reasonable alternative to conventional laminectomy for treating lumbar central stenosis.This trial was registered on CRIS (Clinical Research Information Service, KCT0004355).

Figure 1

Operative image of the three techniques. (a) An image of the operating field applying the retractor after muscle dissection in an open laminectomy, as well as an image of intraoperative level confirmation and a decompressed condition. (b) Appearance of a mounted single portal and the C-arm picture used to examine the surgical level in a full-endoscopic procedure. Endoscopic view of a decompression procedure in uniportal process. (c) Two portals mounted in biportal endoscopic surgery. The C-arm image demonstrated level confirmation and docking of instruments. Endoscopic view of biportal process.

Figure 2

Measurement of the cross-sectional area of the dural sac and multifidus muscle in axial T2-weighted MR images. The area was estimated automatically by tracing a line (red dotted) along the outer wall of the dural. An additional line (yellow solid) was drawn to identify the deteriorated multifidus muscle after surgery. Lean muscle cross-sectional area (CSA) was the sum of all the areas outlined. These methods allow for the comparison of pre- and postoperative conditions, enabling the confirmation of the muscle and dural CSA.

Figure 3

Flow diagram depicting the enrollment, allocation, treatment, and follow-up procedures.

Figure 4

Results of laboratory blood tests conducted before surgery and on the first and third days after surgery. (a) Mean creatine phosphokinase (CPK), U/L (units per liter). (b) Mean lactate dehydrogenase (LDH), IU/L (international units per liter). (c) Mean erythrocyte sedimentation rate (ESR), mm/hr (millimeters per hour). (d) Mean C-reactive protein (CRP), mg/L (milligrams per liter).

Figure 5

Tendency in clinical outcomes among the three groups during the course of a 12-month follow-up. (a) Mean VAS scores for back pain, ranged from 0 (no pain) to 10. (b) Mean VAS scores for leg pain, ranged from 0 (no pain) to 10. (c) Mean Oswestry disability index (ODI) scores, ranged from 0 (no disability) to 100. (d) Mean physical component score (PCS) of 36-item short-form health survey (SF-36), ranged from 0 (severe impairment) to 100. (e) Mean mental component score (MCS) of SF-36, ranged from 0 (severe impairment) to 100.