This study aimed to compare the safety and effectiveness between unilateral biportal endoscopy (UBE) technique and microscopic decompression (MD) technique in lumbar spinal stenosis treatment. PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, and other databases were used to conduct extensive literature searches. RevMan ver. 5.3 software was used for the statistical analysis. Eleven studies were included with 930 patients, including 449 patients in the UBE group and 521 in the MD group. Both techniques revealed similar operative times at −1.77 minutes (95% confidence interval [CI], −7.59 to 4.05 minutes;
Lumbar spinal stenosis is a degenerative disease commonly seen in elderly individuals. Surgical intervention is commonly required for patients who fail conservative treatment. Minimally invasive spine surgery has become a research hotspot in the treatment of spinal degenerative diseases with the rapid development of technology in recent years [
For the first time, this study compared the area of dural sac expansion, the change in C-reactive protein (CRP) value, and the change in patient satisfaction (the modified MacNab score) with lumbar spinal stenosis after two surgical technology treatments compared with the previous meta-analysis [
PubMed, Web of Science, Embase and Cochrane Library, China National Knowledge Infrastructure, WanFang, and VIP databases were used to conduct a comprehensive search. Using subject terms, free words, and a combination of the two, the following search terms were used: “unilateral biportal endoscopy,” “biportal endoscopic spinal surgery,” “biportal endoscopic,” “spine endoscopy,” “microscopic decompression,” “minimally invasive spine,” and “lumbar canal stenosis.” The Boolean operations “AND” and “OR” were used to search. English or Chinese was the language used, and the search time was from the establishment of the database to July 30, 2021. This study did not require Institutional Review Board approval and/or informed consent.
Studies were selected that satisfied the following inclusion criteria: (1) compared the clinical results and laminectomy and decompression efficacy alone in patients with lumbar spinal stenosis treated with UBE and MD techniques. (2) The comparison outcome had at least one of the following: clinical, surgical, and imaging-related parameters (pre- and postoperative Visual Analog Scale [VAS] for leg pain, Oswestry Disability Index [ODI] score, surgery time, blood loss, complications, hospital stay, etc.). (3) The full text could be obtained; complete and useful data could be extracted. The measurement data were expressed as averages±standard deviation. Excluded studies were as follows: (1) case reports, review articles, published abstracts, studies involving fewer than 10 patients, and duplicate data and (2) articles with unavailable access to the full text.
The research object was determined by reading the title and literature abstract according to two independent authors (L.J. and Y.J.). The full text was searched if a decision could not be made. Disagreements were resolved through consensus and discussion with a third party (Y.H.). A bias risk assessment was performed. The reason for nonconformity or exclusion of the study was recorded and described.
Relevant data were extracted by two independent investigators after intensive reading of the full text, mainly including the name of the first author, publication year, study type, sample size, average age, complications, outcome indicators, and follow-up time. Data were statistically tabulated. The third researcher participated in the discussion and made a decision through consultation if there was a disagreement. If necessary, the authors of the literature were contacted to clarify relevant information of the research.
For randomized controlled trials, the evaluation quality refers to the standards recommended by the Cochrane system [
Review Manager software ver. 5.3 (the Cochrane Collaboration, London, UK) was used to perform statistical analysis and the results are represented by forest diagrams. The heterogeneity test was performed when the data were merged. The fixed-effects model was adopted if there was no obvious heterogeneity between the data (
A total of 386 related documents were obtained through a preliminary search. Eleven articles were ultimately included [
Only two of the included studies were randomized controlled trials [
Seven studies were included to evaluate the operation time of the two surgery types with 291 patients in the UBE group and 283 in the MD group [
Three articles were included [
Three articles were included, with 113 patients in the UBE group and 105 in the MD group [
Eleven articles were included, with 449 patients in the UBE group and 521 in the MD group [
Four articles were included, with 168 patients in the UBE group and 171 in the MD group [
Two articles were included, with 65 patients in the UBE group and 60 in the MD group [
Eight articles were included, with 597 patients in the UBE group and 586 in the MD group [
Seven articles were included, with 562 patients in the UBE group and 556 in the MD group [
Only three articles were included, with 106 patients in the UBE group and 90 in the MD group [
The postoperative complications with the most included literature were selected for publication bias analysis, and a funnel chart was made. The 11 points in the figure were roughly symmetrically distributed, indicating that publication bias had a small effect on the results (
MD technology has always been the gold standard treatment for lumbar spinal stenosis [
From this study, there was no significant difference between the two surgical procedures in terms of operation time, postoperative dural expansion area, complications, or the modified MacNab score. The two surgical techniques included complications, preoperative VAS for leg pain and last follow-up (>12 months) VAS for leg pain, and preoperative ODI score and last follow-up (>12 months) ODI score, and there were no significant differences in any of the aspects. However, a subgroup analysis was carried out due to heterogeneity, and results showed no significant differences. This indicates that these two techniques may be equally applicable to the treatment of lumbar spinal stenosis, are safe and effective, and have similar clinical effects.
The spinal canal decompression extent can be studied using magnetic resonance imaging to measure the dural mater area after surgery. Two minimally invasive surgical techniques were used to treat lumbar spinal stenosis after sufficient decompression, and spinal canal stenosis was significantly enlarged. UBE technique was more flexible and the decompression was more thorough although there was no significant difference between the two, especially for patients with severe lumbar central canal stenosis [
Serum creatine kinase (CK) and CRP have been used as parameters to assess muscle injury and acute inflammation, respectively. It was impossible to compare the two techniques in terms of surgical trauma due to the lack of postoperative CK data in this study. The results may have been affected by the large heterogeneity of the included studies although the results of this study showed that there were no significant differences in CRP 1 week after the operation. Choi and Kim [
The results of this study showed that the UBE technique has lower intraoperative blood loss and hospital stay than the MD technique. There were still significant differences between the two surgical techniques although the included studies were heterogeneous. The average length of hospital stay for patients treated with the UBE technique was 3.06 days shorter than that with the MD technique, likely due to UBE’s ability to minimize tissue damage and reduce operative muscle and ligament damage, intraoperative blood loss, and postoperative back pain recovery time [
This study has some limitations that need to be acknowledged. First, the best evidence for a systematic review is a randomized controlled trial. However, this systematic review only included two randomized controlled trials and the remaining nine were retrospective controlled studies, which may have distorted the results due to selection and recall bias. Second, the few included studies and the inconsistency of the results of the included studies indicate a high degree of variability in the results. Third, in the data included in this study for comparison, only the intraoperative blood loss and hospital stay were significantly different, and the heterogeneity showed obvious heterogeneity, which may be related to factors that depend on the operation situation and other variables. Further studies should be conducted with the same baseline and a larger sample size. The results of this study still have practical guiding significance despite the limitations.
There were no significant differences in the efficacy or safety of UBE and MD technology in the treatment of patients with lumbar spinal stenosis. However, UBE technology has less intraoperative bleeding and a shorter hospital stay. It can be well applied to lumbar spinal stenosis. It has a slight advantage and is a better surgical option than MD technology. More randomized controlled studies are needed to strengthen the current findings due to the inclusion of fewer studies.
No potential conflict of interest relevant to this article was reported.
This study was supported by the National Natural Science Foundation of China (No. 81760231; No. 81160220); Natural Science Foundation of Ningxia Hui Autonomous Region (CN) (No. NZ17153; No. NZ11197); First-Class Discipline Construction Founded Project of NingXia Medical University and the School of Clinical Medicine (NXYLXK2017A05); and Natural Science Foundation of Ningxia Hui Autonomous Region (No. 2022AAC03398).
Conception and design: Li Junjie, Yuan Haifeng; data acquisition: Li Junjie, Yin Jiheng, Liu Jun; analysis of data: Li Junjie, Yin Jiheng, Liu Jun; drafting of the manuscript: Li Junjie; critical revision: Li Junjie, Yin Jiheng, Liu Jun, Yuan Haifeng; obtaining funding: Lin haixiong, Yuan Haifeng; administrative support: Lin haixiong, Yuan Haifeng; and supervision: Yuan Haifeng.
PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) flow chart for the study search.
Judgement of the risk of bias included in the randomized controlled trial (RCT).
Forest plot of operation times for unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). SD, standard deviation; IV, inverse variance; CI, confidence interval; df, degrees of freedom.
Forest plot of estimated blood loss for unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). SD, standard deviation; IV, inverse variance; CI, confidence interval; df, degrees of freedom.
Forest plot of the area of dural sac expansion for unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). SD, standard deviation; IV, inverse variance; CI, confidence interval; df, degrees of freedom.
Forest plot of complications associated with unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). M-H, Mantel–Haenszel; CI, confidence interval; df, degrees of freedom.
Forest plot of lengths of hospital stay for unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). SD, standard deviation; IV, inverse variance; CI, confidence interval; df, degrees of freedom.
Forest plot of CRP for the unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). SD, standard deviation; IV, inverse variance; CI, confidence interval; df, degrees of freedom.
Subgroup analysis forest plot of preoperative and postoperative end of follow-up (more than 12 months) Visual Analog Scale (VAS) for leg pain for the unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). SD, standard deviation; IV, inverse variance; CI, confidence interval; df, degrees of freedom.
Subgroup analysis forest plot of preoperative and postoperative end of follow-up (more than 12 months) Oswestry Disability Index (ODI) scores for unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). SD, standard deviation; IV, inverse variance; CI, confidence interval; df, degrees of freedom.
Forest plot of patient satisfaction (the modified MacNab score) for unilateral biportal endoscopy (UBE) vs. microscopic decompression (MD). M-H, Mantel–Haenszel; CI, confidence interval; df, degrees of freedom.
Funnel diagram of complications in the two surgical methods. OR, odds ratio; SE, standard error.
Characteristics of included studies
Study | Design | Country | No. of patients (UBE/MD) | Age (yr) (UBE/MD) | Sex (M:F), (UBE/MD) | No. of levels | Complications | Outcomes | Final follow-up (mo) |
---|---|---|---|---|---|---|---|---|---|
Min et al. [ |
Case control study | Korea | 54/35 | 65.74±10.52/66.74±7.96 | 27:27/19:16 | All single level | UBE: dural tear (n=2), postoperative epidural hematoma (n=1); MD: dural tear (n=1), postoperative epidural hematoma (n=1) | VAS for back and leg; ODI; operative time; modified Macnab criteria; complication | UBE: 27.2±5.4 |
Ito et al. [ |
Single-center, retrospective analysis | Japan | 42/139 | 66.3±12.3/65.0±11.1 | 28:14/71:68 | All single level | UBE: dural injury (n=2); MD: hematoma (n=5), dural injury (n=8), reoperation (n=2) | VAS for back and leg; ODI; operative time; bone resection area; facet; preservation rates; EQ-5D questionnaire; complication | UBE: 6.7±0.6 |
Kim et al. [ |
Multicenter, retrospective analysis | Korea | 60/81 | 46.60±14.18/54.22±20.21 | 37:23/24:57 | All single level | UBE: change the surgical plan (n=3); MD: cerebrospinal fluid leakage (n=1), cerebrospinal fluid leakage and infection (n=1) | VAS for back and leg; ODI; operative time; complication; estimated blood loss; hospital stay; MacNab score; complications | UBE: 12.60±1.03 |
Heo et al. [ |
Retrospective analysis of prospectively | Korea | 37/33 | 66.7±9.4/63.4±11.1 | 15:22/12:21 | All single level | UBE: durotomy (n=1), postoperative hematoma (n=1) MD: durotomy (n=2), transient weakness (n=1), postoperative hematoma (n=2) | VAS for back and leg; ODI; operative time; dura expansion; angle of facetecomy; complication | UBE: 12.5±3.3 |
Kim et al. [ |
Retrospective study | Korea | 30/30 | 64.23±5.26/66.20±6.01 | 13:17/12:18 | All single level | UBE: cerebrospinal fluid leak (n=1); MD: cerebrospinal fluid leak (n=2), surgical site infection (n=1) | VAS; ODI; operative time; dura expansion; estimated blood loss; serum creatine kinase; CRP; modified MacNab score; complication | UBE: 12 |
Heo et al. [ |
A case control prospective study | Korea | 46/42 | 65.8±8.9/63.6±10.5 | 18:28/16:26 | All single level | UBE: durotomy (n=1), postoperative hematoma (n=1); MD: durotomy (n=1), postoperative hematoma (n=2) | VAS for back and leg; ODI; operative time; cross-sectional area of the dura; complication | UBE: 14.5±2.3 |
Park et al. [ |
Randomized controlled trial | Korea | 32/32 | 66.2 (41–80)/ 67.1 (45–79) | 13 :19/18 :14 | All single level | UBE: incidental durotomy (n=2), postoperative epidural hematoma (n=1); MD: incidental durotomy (n=2), postoperative epidural hematoma (n=1), revision surgery due to recurrent pain (n=1) | VAS for back and leg; ODI; operative time; complication; EQ-5D score; hospital stay; postoperative drainage; serum creatine phosphokinase | UBE: 12 |
Kang et al. [ |
A prospective randomized comparative study | Korea | 32/30 | 65.1±8.6/67.2±9.5 | 18:14/14:16 | All single level | UBE: revision (n=1); MD: revision (n=1) | Operative time; hospital stay; Hemovac drain output; complication | UBE: 6 |
Choi et al. [ |
Retrospective study | Korea | 35/30 | 65.4±11.8/65.2±12.0 | 14:21/17:13 | UBE: single level (24), multiple levels (11); MD: single level (15), multiple level (15) | UBE: dural tear (n=2), root injury (n=1); MD: dural tear (n=2) | VAS for back and leg; ODI; CRP; complication; postoperative hemoglobin; transfusion | UBE: 6 |
Tuo et al. [ |
Retrospective analyzed | China | 22/25 | 59.1±11.7/58.3±8.7 | 12:10/11:14 | All single level | UBE: postoperative epidural hematoma (n=1), dura tear (n=3) MD: postoperative epidural hematoma (n=1), dura tear (n=5) | VAS; ODI; operative time; hospital stay; intraoperative blood loss; complication; modified MacNab criteria | UBE: 12 |
Lee et al. [ |
Retrospective | Korea | 59/44 | 69.64±11.05/69.11±8.58 | 30:29/16:28 | All single level | UBE: dura tear (n=6), infection (n=2), postoperative epidural hematoma (n=1), incomplete decompression (n=2), others (n=1); MD: dura tear (n=4), infection (n=2), postoperative epidural hematoma (n=1), others (n=1) | VAS for back and leg; ODI; operative time; drainage volume; hospital stay; complication | UBE: 3 |
Values are presented as number, mean±standard deviation, or mean (range), otherwise stated.
UBE, unilateral biportal endoscopy; MD, microscopic decompression; M, male; F, female; VAS, Visual Analog Scale; ODI, Oswestry Disability Index; EQ-5D, European Quality of Life-5 Dimensions; CRP, C-reactive protein.
Quality evaluation according to the Risk of Bias Assessment of Non-randomized Studies Scale
Study | Selection of participants | Confounding variables | Measurement of exposure | Blinding of outcome assessment | Incomplete outcome data | Selective reporting outcome |
---|---|---|---|---|---|---|
Min et al. [ |
Low risk | Unclear risk | Low risk | High risk | Low risk | Low risk |
Ito et al. [ |
Low risk | Low risk | Low risk | High risk | Low risk | Low risk |
Kim et al. [ |
Low risk | Low risk | Low risk | High risk | Low risk | Low risk |
Heo et al. [ |
Low risk | High risk | Unclear risk | High risk | Low risk | Low risk |
Lee et al. [ |
Low risk | Unclear risk | Low risk | High risk | Low risk | Low risk |
Choi et al. [ |
Low risk | High risk | Unclear risk | High risk | Low risk | Low risk |
Tuo et al. [ |
Low risk | Low risk | Low risk | High risk | Low risk | Low risk |
Kim et al. [ |
Low risk | High risk | Low risk | High risk | Low risk | Low risk |
Heo et al. [ |
Low risk | Low risk | Low risk | High risk | Low risk | Low risk |