The evidence indicated that operative time, blood loss and complication rates were significantly reduced with percutaneous endoscopic lumbar discectomy in patients with recurrent lumbar disc herniation in comparison with open lumbar microdiscectomy. Whereas, the difference between the treatment groups were similar in terms of pain reduction, global perceived effect (MacNab score), re-operation and recurrence rate. Hence, percutaneous endoscopic lumbar discectomy could be used as an alternative to the conventional procedure in the treatment of recurrent lumbar disc herniation. Search terms were provided, but a full search strategy was not reported, therefore it was not possible to judge if all relevant studies had been retrieved. Further high-quality randomised controlled trials were required to address the present review question.
Overall summary Risk of bias unclear
Search terms were provided but a full search strategy was not reported, therefore it was not possible to judge if all relevant studies had been retrieved.
|A. Did the interpretation of findings address all of the concerns identified in Domains 1 to 4?||No information|
|B. Was the relevance of identified studies to the review's research question appropriately considered?||Probably yes|
|C. Did the reviewers avoid emphasizing results on the basis of their statistical significance?||Probably yes|
|Risk of bias in the review||Unclear|
|Number of studies||8|
|Number of participants||475|
|Last search date||July 2015|
|Objective||To evaluate the effectiveness of percutaneous endoscopic lumbar discectomy in the treatment of recurrent lumbar disc herniation and to present its indications and techniques.|
|Population||Patients with recurrent lumbar disc herniation (verified by radiological examination).
The studies in which primary lumbar disc herniation operated by percutaneous endoscopic lumbar discectomy were excluded.
|Interventions||Percutaneous endoscopic lumbar discectomy.
Studies in which treatment with percutaneous endoscopic transforaminal discectomy or percutaneous endoscopic interlaminar discectomy were included.
|Comparator||Open lumbar microdiscectomy and conventional microsurgical.|
|Outcome||Leg pain and back pain (measured using visual analogue scale), functional status (assessed using Oswestry disability index), global perceived effect (McNab score/the percentage of patients satisfactory), and other outcomes (recurrences, complications, re-operation), dural tear incidence, operation time, blood loss and hospital stay.|
|Study design||Prospective randomised controlled trial, retrospective controlled studies, prospective cohort studies and observational retrospective studies.
The literature of review were excluded.
The mean overall operative time of percutaneous endoscopic lumbar discectomy (PELD) for recurrent lumbar disc herniation (rLDH) was 47.37 minutes (24 to 79.06; five studies, n=177 patients). The mean overall improvement of leg pain (assessed using visual analogue scale (VAS) score) was 66.92% (50.6% to 89.87%; seven studies, n=457 patients), back pain (VAS score) 54.91% (29% to 67.95%; five studies, n=339 patients), Oswestry disability index (ODI) was 60.9% (40.7% to 75%; four studies, n=111 patients) and the global perceived effect (MacNab score) 75.77% (60% to 95%; five studies, n=391 patients).
The mean overall complications rate was 4.89% (0% to 9.76%; five studies, n=177 patients), re-operation rate was 3.66% (2.33% to 4.8%; three studies, n=110 patients), recurrence rate was 6.3% (4% to 10%; six studies, n=414 patients) and total dural tear rate was 0.1% (0% to 4.9%, seven studies, n=213 patients).
Pooled analysis of three trials reported a statistically significant reduction in the operation time in patients who received PELD (when compared to those who received open microdiscectomy (OD) (mean difference (MD) = -59.08, 95% confidence interval (CI) -98.03 to -20.13; n=197 patients). Similarly, a statistically significant reduction in blood loss (MD = -161.73, 95% CI -418.46 to 95.01; two studies, n=143 patients) and hospital stay (MD = -6.49, 95% CI -13.83 to 0.84; two studies, n=97 patients) were observed in the PELD group than in the OD group.
No significant difference was observed between PELD and OD groups in terms of improvement in back pain (VAS score) (MD = -0.28, 95% CI -3.90 to 3.33; two studies, 141 patients), improvement in leg pain (VAS score) (MD=2.03, 95% CI -1.38 to 5.44), ODI (MD = -3.62, 95% CI -13.93 to 6.70; two studies, 141 patients) and incidence of recurrence (risk ratio (RR) = 0.53, 95% CI 0.13 to 2.22; three trials, n=184 patients).
Summary estimates from three studies showed a significant reduction in the incidence of complications in the PELD group (RR=0.24, 95% CI 0.08 to 0.71; n=197 patients) compared to the OD group.
The eligibility criteria were well described and appeared appropriate to address the present review question. Studies with more than 10 cases were included and found to be appropriate. No restriction was reported based on the sources of information.
|1.1 Did the review adhere to pre-defined objectives and eligibility criteria?||Probably yes|
|1.2 Were the eligibility criteria appropriate for the review question?||Probably yes|
|1.3 Were eligibility criteria unambiguous?||Probably yes|
|1.4 Were all restrictions in eligibility criteria based on study characteristics appropriate (e.g. date, sample size, study quality, outcomes measured)?||Probably yes|
|1.5 Were any restrictions in eligibility criteria based on sources of information appropriate (e.g. publication status or format, language, availability of data)?||Probably yes|
|Concerns regarding specification of study eligibility criteria||Low|
MEDLINE, EMBASE, Web of Science and Cochrane databases were searched for relevant studies. The reference lists of eligible studies and relevant reviews were checked for additional relevant studies. Search terms were provided, but a full search strategy was not reported. The searches were not restricted to date, publication format or language. Two review authors were independently involved in the study selection process and any disagreement between them was resolved by discussion with the corresponding author.
|2.1 Did the search include an appropriate range of databases/electronic sources for published and unpublished reports?||Probably yes|
|2.2 Were methods additional to database searching used to identify relevant reports?||Probably yes|
|2.3 Were the terms and structure of the search strategy likely to retrieve as many eligible studies as possible?||No information|
|2.4 Were restrictions based on date, publication format, or language appropriate?||Probably yes|
|2.5 Were efforts made to minimise error in selection of studies?||Yes|
|Concerns regarding methods used to identify and/or select studies||Unclear|
Two review authors were independently involved in the data extraction process and re-checked by one author. Sufficient study characteristics appeared to have been extracted to allow interpretation of the results and study results were appropriately collected for the synthesis. Methodological quality of the included controlled trials and non-control studies were assessed according to the 12 criteria and instructions recommended by the Cochrane Back Review Group and modified 5-point assessment score respectively. Two review authors were independently involved in the risk of bias assessment and any disagreements were resolved by discussion with the corresponding author.
|3.1 Were efforts made to minimise error in data collection?||Yes|
|3.2 Were sufficient study characteristics considered for both review authors and readers to be able to interpret the results?||Probably yes|
|3.3 Were all relevant study results collected for use in the synthesis?||Probably yes|
|3.4 Was risk of bias (or methodological quality) formally assessed using appropriate criteria?||Probably yes|
|3.5 Were efforts made to minimise error in risk of bias assessment?||Yes|
|Concerns regarding methods used to collect data and appraise studies||Low|
The synthesis included all eligible studies. The method of analysis was explained and appeared to be appropriate. There was significant evidence of heterogeneity for five outcomes (operation time, blood loss, hospital stay, back pain and leg pain). Appropriate attempts were not made to explore the possible sources of heterogeneity due to less numbers of studies for each outcome (two to three studies). Publication bias was not feasible due to the low number of studies included for each comparison. The quality of individual studies was considered in the synthesis.
|4.1 Did the synthesis include all studies that it should?||Probably yes|
|4.2 Were all pre-defined analyses reported or departures explained?||Probably yes|
|4.3 Was the synthesis appropriate given the degree of similarity in the research questions, study designs and outcomes across included studies?||Probably yes|
|4.4 Was between-study variation minimal or addressed in the synthesis?||Probably yes|
|4.5 Were the findings robust, e.g. as demonstrated through funnel plot or sensitivity analyses?||Probably yes|
|4.6 Were biases in primary studies minimal or addressed in the synthesis?||Probably yes|
|Concerns regarding synthesis and findings||Low|
The objective of this systematic review was to identify the effectiveness of percutaneous endoscopic lumbar discectomy (PELD) in the treatment of recurrent lumbar disc herniation (rLDH) and to present its indications and techniques. We conducted a comprehensive search in MEDLINE, EMBASE, PubMed, Web of Science and Cochrane databases, searching for relevant studies of managing rLDH with PELD up to July 2015. Only papers published in English were included. Two review authors independently selected the studies, extracted relevant data and assessed their methodological quality. The Cochrane Collaborations Revman 5.3 software was used for data analyses among the controlled studies. At last, one randomized controlled trial (RCT), two non-randomized control studies and five observational studies including a total of 579 cases were selected for this system review. The methodological quality of these studies was low to modern. The mean overall improvement of leg pain (visual analogue scale) was 66.92% (50.6%-89.87%), back pain (visual analogue scale) 54.91% (29%-67.95%), Oswestry Disability Index 60.9% (40.7%-75%), global perceived effect (MacNab/other) 75.77% (60%-95%). The mean overall of complication rate was 4.89% (0%-9.76%), dural tear rate 0.1% (0%-4.9%), recurrence rate 6.3% (4%-10%), re-operation rate 3.66% (2.33%-4.8%). We conducted a meta-analysis among the control trials. Compared with Open discectomy (OD), PELD resulted in better outcomes in terms of operative time, blood loss, lower complication rates, but with no significance differences regarding hospital stay, second recurrence rate, Macnab criteria and pain reduction. In conclusion, according to the current evidence, PELD is an effective procedure for the treatment of rLDH in terms of reducing complication and shorting hospital course, comparing with OD. Therefore, we suggested that PELD was a feasible alternative to OD in the treatment of the rLDH in the condition of proper indication. High-quality RCTs with large sample sizes are needed to further confirm these results. Copyright © 2016 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.