Long-term outcomes of primary percutaneous endoscopic lumbar discectomy: systematic review and meta-analysis

Article information

Asian Spine J. 2026;.asj.2025.0572

Publication date (electronic) : 2026 April 23

doi : https://doi.org/10.31616/asj.2025.0572

Conor McNamee ¹^,², David Kelly ¹^,², Oisin Shannon ¹^,², Jake Michael McDonnell ¹, Stacey Darwish ¹^,³, Joseph Simon Butler ¹^,²

¹National Spine Injuries Unit, Mater Misericordiae University Hospital, Dublin, Ireland

²University College Dublin, Dublin, Ireland

³Saint Vincent’s University Hospital, Dublin, Ireland

Corresponding author: Conor McNamee, National Spine Injuries Unit, Mater Misericordiae University Hospital, Eccles Street, Dublin 7, Ireland, Tel: +353-892318757, E-mail: conor.mcnamee@ucdconnect.ie

Received 2025 September 15; Revised 2025 November 5; Accepted 2025 December 14.

Abstract

Study Design

Systematic review and meta-analysis.

Objectives

To evaluate long-term functional, radiological, and surgical outcomes of percutaneous endoscopic lumbar discectomy (PELD).

Overview of Literature

Early studies suggest that PELD achieves outcomes comparable to those of microdiscectomy with less perioperative morbidity and faster recovery, although technical challenges contribute to a steep learning curve. Long-term data remain sparse, and observational studies are necessary to assess late outcomes.

Methods

A systematic search of the PubMed, Embase, and Scopus databases was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies that reported outcomes at ≥5 years after PELD were included. The Visual Analog Scale (VAS) for leg and back pain, Oswestry Disability Index (ODI), Japanese Orthopedic Association score, disc height, range of motion (ROM), complication rates, recurrent herniation, and reoperation rates were assessed. Data were extracted and pooled using random-effects meta-analysis as appropriate. The risk of bias was assessed using the National Institute of Health Quality Assessment Tool.

Results

Nine studies including 2,369 patients undergoing transforaminal or interlaminar PELD with a mean follow-up of ≥5 years were analyzed. Pooled functional outcomes at ≥5 years were favorable: VAS (leg) 1.09, VAS (back) 1.18, and ODI 11.98. The proportion of patients with good/excellent results according to the MacNab criteria was 88%. Recurrence and reoperation rates were 6% and 7%, respectively, similar to those reported after microdiscectomy in historical cohorts. Radiological outcomes showed modest disc height reduction and preserved ROM without evidence of long-term instability based on flexion-extension ROM. Most complications were early, transient, and infrequent.

Conclusions

PELD may provide sustained symptom relief and low rates of complication, recurrence, and reoperation in long-term follow-up. Late clinical and functional outcomes appear to be favorable. However, the predominance of retrospective data and selective loss to follow-up limits the strength of the conclusions.

Keywords: Percutaneous endoscopic lumbar discectomy; Lumbar disc herniation; Recurrence; Systematic review

Introduction

Percutaneous endoscopic lumbar discectomy (PELD) is an emerging minimally invasive alternative to open and tubular microdiscectomy for treating symptomatic lumbar disc herniation. Generally, PELD is performed using either the transforaminal or interlaminar route, with each offering distinct advantages. Transforaminal techniques exploit Kambin’s triangle, a natural working corridor that provides direct access to the disc space with minimal soft tissue dissection [1]. By avoiding subperiosteal dissection of the paraspinal musculature and minimizing disruption to the stabilizing ligamentous structures, transforaminal PELD may reduce postoperative muscle denervation [2], atrophy, and subsequent segmental instability [3] compared with conventional posterior midline techniques. Interlaminar PELD is particularly valuable at the L5–S1 segment, which has a notably wide interlaminar space and where anatomical variants such as a high iliac crest can impede the more lateral transforaminal approach [4]. Through direct endoscopic visualization via the interlaminar window, effective decompression is similarly achieved without extensive tissue disruption.

Early results from randomized and observational studies suggest that PELD provides symptom relief and functional recovery comparable to those of microdiscectomy, with the added benefits of reduced perioperative morbidity and a shorter hospital stay [5–8]. Furthermore, PELD procedures are frequently conducted under local or regional anesthesia, allowing for same-day patient discharge and increased surgical efficiency [9]. These early advantages are largely attributed to the preservation of native anatomy, which may also lead to favorable outcomes over the longer term. However, the technical challenges inherent to endoscopic discectomy, primarily altered visualization [10] and confined working channels, contribute to an extended learning curve. Such limitations also raise concerns regarding the adequacy of decompression, the possibility of residual or recurrent pathology, and the possibility of delayed treatment failure. Therefore, further research explicitly evaluating long-term clinical and functional outcomes after PELD is necessary; however, such studies are few.

The relative absence of long-term data poses a significant challenge for surgical decision-making. While randomized controlled trials (RCTs) remain the gold standard, they are often limited by short follow-up durations, small sample sizes, and difficulty in retaining participants over time. As a result, RCTs are often underpowered to detect late complications or capture gradual changes in function [11]. These limitations are particularly pertinent in spine surgery, where symptom recurrence and reoperation may occur several years after the index procedure. For these reasons, well-designed observational trials will likely remain a valuable and pragmatic complement to randomized evidence when assessing long-term real-world outcomes and complication profiles [12].

This systematic review and meta-analysis aimed to address the current evidence gap by synthesizing the available evidence on long-term outcomes after PELD, specifically focusing on functional improvement, complication rates, recurrent disc herniation, reoperation rates, and radiographic changes after transforaminal or interlaminar endoscopic lumbar discectomy.

Methods

Two independent reviewers (D.K. and O.S.) searched the literature according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) [13]. The PubMed, Embase, and Scopus databases were queried on June 16, 2024, without a publication date restriction. The following search string was used for all the databases: (“endoscopic lumbar dis*ectomy” OR “percutaneous endoscopic lumbar dis*ectomy” OR PELD OR TELD OR IELD OR “full endoscopic” OR “full-endoscopic” OR “transforaminal endoscopic lumbar dis*ectomy” OR “interlaminar endoscopic lumbar dis*ectomy”) AND (“cohort*” OR “observational” OR “RCT” OR “randomi*ed controlled trial*” OR “outcome*” OR “complication*” OR “reherniation*” OR “reherniation*” OR “recurrence*” OR “revision*”) NOT (“pediatric end-stage liver disease” OR “pediatric end-stage liver disease”).

Duplicate studies were manually identified through digital object identifier (DOI)/PubMed identifier (PMID) and title checks and then removed. The two reviewers independently screened the results based on the title and abstract, applying exclusion criteria (Table 1). The remaining full texts were then independently assessed according to the inclusion criteria (Table 1). In cases of disagreement, one author (J.M.) acted as the final decision maker regarding study inclusion. Corresponding authors were emailed to obtain inaccessible full texts, and studies were excluded if no copy was received.

Table 1

Inclusion/exclusion criteria during record screening process

Data extraction

Data were independently extracted by two authors (D.K. and O.S.) using a standardized data collection form. Extracted variables included study identifiers (author, year, DOI, and study number), country of origin, enrollment period, study design, surgical technique (including anesthesia type), indications and exclusion criteria, and the number of treated patients. Patient demographic variables included age, sex distribution, body mass index, smoking status, and mean duration of follow-up. Radiographic levels treated (L1–S1) and outcome measures were also recorded. Continuous outcomes included the Visual Analog Scale (VAS) scores for back and leg pain, the Oswestry Disability Index (ODI), the Japanese Orthopedic Association (JOA) score, disc height (mm), and range of motion (ROM), with corresponding standard deviations where available. Binary outcomes included the rates of good/excellent modified MacNab classification, aggregate complications, recurrent herniation, and revision surgery.

Quality assessment

The National Institute of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies was used to assess the risk of bias [14]. This tool includes 14 items assessing aspects such as the clarity of the research question, specification of the study population, sample size justification, and control for confounding variables. Each item is rated as “yes,” “no,” “cannot determine,” “not applicable,” or “not reported.” Reviewers make an overall decision regarding study quality based on the presence or absence of key sources of bias relevant to the study design and research question. In the current study, these were judged to be loss to follow-up and exclusion due to insufficient follow-up or sample size. The risk of bias was assessed independently by two authors (C.M. and D.K.), with consensus used to resolve disagreements.

Meta-analysis

Any outcome reported in three or more investigations was subsequently meta-analyzed. Using R and the meta package (The R Foundation for Statistical Computing, Vienna, Austria), binary outcomes were pooled using a random-effects model with inverse variance weighting and logit transformation of proportions. Confidence intervals (CIs) were calculated using the Clopper-Pearson method [15], which provides conservative but exact CIs for binomial proportions. Continuous outcomes were pooled as raw means (MRAW) using a random-effects model with inverse variance weighting and the DerSimonian–Laird method to estimate between-study variance [16]. CIs were calculated using normal approximation. Random-effects models were selected a priori. In the forest plots, horizontal lines represent the 95% CI of the reported values. The solid squares represent each study’s reported mean and are proportional in size to the weights calculated for the meta-analysis. The diamond shows the pooled mean, with the lateral tips of the diamond indicating the associated 95% CI.

Results

The literature search identified 4,264 studies (PubMed: 1,169, Embase: 1,732, Scopus: 1,363). After removing 2,304 duplicates, the remaining 1,960 studies were screened according to exclusion criteria, yielding 88 reports for full-text assessment, of which 11 records were inaccessible. The screening procedure is illustrated in Fig. 1.

Fig. 1

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) flow diagram of systematic literature search.

Study characteristics

After screening, nine studies comprising 2,369 patients with an average age of 47.2 years were included. Five studies described solely transforaminal PELD techniques [17–21], three described both interlaminar and transforaminal approaches [22–24], and one detailed only interlaminar PELD [24]. Eight investigations were retrospective cohort studies [17–19,21–25] and one was a prospective observational study [20]. The mean follow-up time ranged from 5 to 11.2 years, with a mean of 6.9 years. Five studies specifically reported the number of patients excluded from the analysis due to insufficient follow-up [16–21], while this information was omitted in the remainder. The most common indication for surgery was lumbar disc herniation, while two studies included patients with concurrent lateral recess or foraminal stenosis [18,20]. All reports detailed the distribution of operated levels, and the most common operated levels were L4/L5 and L5/S1 across all investigations. Patients included in the interlaminar arm of the study by Wu et al. [24] were operated under general anesthesia, while all seven other investigators reporting anesthetic factors described a combination of local and regional techniques [17–20,22–24]. When assessing study quality, loss to follow-up and exclusions due to inadequate follow-up duration were the most frequent sources of bias. The reporting of demographic variables and outcome definitions was generally adequate. Prospective data were limited but demonstrated higher methodological quality. A summary of the included reports is shown in Table 2.

Table 2

Summary of included reports

Functional outcomes

VAS (leg) and ODI [17–20,22–25] were the most commonly reported functional outcomes, each included in eight studies [17–20,22–25]. Li et al. [20] reported VAS scores ranging from 0 to 100. Values from this study were divided by 10 to facilitate comparison with all remaining investigations that used scales ranging from 0 to 10. All functional measures improved at the final follow-up compared to preoperative values. The mean preoperative VAS (leg) score was 6.40, with a mean decrease of −5.29 to 1.11 by 5 or more years after surgery. ODI showed similar improvement from a preoperative mean of 58.31, with a mean change of −46.30 to 12.01, at long-term follow-up. Table 3 displays the mean values of all functional measures before surgery and at the final follow-up.

Table 3

Reported functional measures before surgery and at the long-term follow-up

VAS score (leg)

The pooled VAS (leg) score 5 years postoperatively among 663 patients was 1.09 (95% CI, 0.62 to 1.56). The heterogeneity was high (I²=98.5%, p<0.01). Fig. 2 illustrates the reported scores and the pooled results.

Fig. 2

Forest plot showing Visual Analog Scale (VAS) (leg pain) 5+ years post-percutaneous endoscopic lumbar discectomy (PELD). SD, standard deviation; MRAW, raw mean; CI, confidence interval; IL, interlaminar PELD; TF, transforaminal PELD.

VAS score (back)

VAS (back) was included in seven investigations comprising 599 patients [17,19,20,22–25]. The pooled backpain score was 1.18 (95% CI, 0.72 to 1.63) at 5 years or more following surgery. The heterogeneity was high (I²=97.4%, p<0.01). The results are shown in Fig. 3.

Fig. 3

Forest plot showing Visual Analog Scale (VAS) (back pain) 5+ years post-percutaneous endoscopic lumbar discectomy (PELD). SD, standard deviation; MRAW, raw mean; CI, confidence interval; IL, interlaminar PELD; TF, transforaminal PELD.

ODI

ODI was reported in eight studies involving 663 patients at 5 or more years post-procedure [17–20,22–25]. The pooled ODI was 11.98 (95% CI, 9.28 to 14.68). The heterogeneity was high (I²=97.7%, p<0.01). Fig. 4 shows a forest plot of this analysis.

Fig. 4

Forest plot showing Oswestry Disability Index (ODI) 5+ years post-percutaneous endoscopic lumbar discectomy (PELD). SD, standard deviation; MRAW, raw mean; CI, confidence interval; IL, interlaminar PELD; TF, transforaminal PELD.

Modified MacNab criteria

Six studies comprising 561 patients described the proportion of good/excellent surgical results, as measured using the modified MacNab criteria [17,19,20,23–25]. The meta-analysis found that the pooled proportion of patients achieving this benchmark after 5 or more years was 0.877 (95% CI, 0.841 to 0.905). The heterogeneity was low (I²=14.5%, p=0.32). The results are shown in Fig. 5.

Fig. 5

Forest plot showing proportion of good/excellent MacNab criteria 5+ years post-percutaneous endoscopic lumbar discectomy (PELD). CI, confidence interval; TF, transforaminal PELD; IL, interlaminar PELD.

JOA score

Three studies consisting of 157 patients reported the JOA score [18,19,23]. The pooled JOA score 5 or more years post-PELD was 24.87 (95% CI, 23.51 to 26.22). The heterogeneity was high (I²=87.6%, p<0.01). The results are shown in Fig. 6.

Fig. 6

Forest plot showing Japanese Orthopedic Association (JOA) score 5+ years post-percutaneous endoscopic lumbar discectomy (PELD). SD, standard deviation; MRAW, raw mean; CI, confidence interval.

Radiological outcomes

Four investigations reported radiological outcomes at a minimum of 5 years follow-up after primary PELD. Tang et al. [18] reported absolute disc height in millimeters, while Li et al. [23] in 2024, Eun et al. [22] and Li et al. [19] in 2021 reported various disc height ratios. Tang et al. [18] and Li et al. [23] in 2024 also reported changes in segmental ROM assessed using flexion-extension radiographs.

Tang et al. [18] observed a minimal loss in disc height and preserved segmental ROM at 6 years, with the postoperative disc height and ROM averaging 10.19±0.66 mm and 5.41°±2.31°, respectively, compared to preoperative values of 10.22±0.65 mm and 5.59°±2.22°, respectively.

At over 8 years of follow-up, Li et al. [23] in 2024 reported a modestly reduced disc height index, defined as twice the height of the intervertebral disc divided by the sum of the heights of the superior and inferior vertebrae, from 35.23%±4.10% preoperatively to 30.72%±2.96% postoperatively, with ROM maintained (5.47°±0.75° preoperative vs. 5.78°±0.69° postoperative).

Li et al. [19] in 2021 and Eun et al. [22] defined disc height ratio as the ratio of postoperative to preoperative disc height, with a reduction to 84.52%±5.66% and 81.54%±17.4% at mean follow-ups of 8 and 11 years, respectively.

Complications

Intra- and postoperative complications were reported in six studies involving 567 patients [17–20,23,25], with dysesthesia, muscle weakness, and dural tears being the most frequent. Dysesthesia was described in five studies [17–20,25], affecting 33 patients. While the majority experienced transient symptoms, eight patients had persistent dysesthesia at follow-up [17,19]. Muscle weakness occurred in four patients across two studies, with full resolution reported in all instances [17,18]. Dural tears were documented in six patients from three studies [17,18,25], and a small number of hematomas were also reported. Recurrent disc herniation was excluded from this analysis and evaluated separately. The pooled proportion of patients experiencing complications at 5 years after PELD was 0.091 (95% CI, 0.043 to 0.181). The heterogeneity was high (I²=84.0%, p<0.01). The results are shown in Fig. 7.

Fig. 7

Forest plot showing proportion of patients suffering complications 5+ years post-percutaneous endoscopic lumbar discectomy (PELD). CI, confidence interval.

Recurrent disc herniation

All included studies reported instances of recurrent disc herniation occurring at the same level as the initial surgery [17–25]. This analysis comprised 2,369 patients. Recurrences occurred as early as 1 month postoperatively [18,19] and as late as 72 months postoperatively [21]. The largest study, involving 1,706 patients, reported a mean recurrence interval of 27.4 months [21]. The pooled proportion of patients suffering recurrence was 0.067 (95% CI, 0.044 to 0.099). The heterogeneity was moderate (I²=60.1%, p=0.01). The results are shown in Fig. 8.

Fig. 8

Forest plot showing proportion of patients suffering recurrent herniation 5+ years post-percutaneous endoscopic lumbar discectomy (PELD). CI, confidence interval. IL, interlaminar PELD; TF, transforaminal PELD.

Reoperation rate

Six investigators reported the number of reoperations [17–20,22,24] in 564 patients. Eun et al. [22] was an outlier in this analysis, describing six patients who required revision open microdiscectomy for recurrence and another 17 patients requiring subsequent decompression at another level from a cohort of 62 patients with a mean follow-up of 11 years. The pooled proportion of patients undergoing reoperation at 5 years was 0.072 (95% CI, 0.026 to 0.186). The heterogeneity was high (I²=89.1%, p<0.01). The results are shown in Fig. 9.

Fig. 9

Forest plot showing proportion of patients undergoing reoperation 5+ years post-percutaneous endoscopic lumbar discectomy (PELD). CI, confidence interval. IL, interlaminar PELD; TF, transforaminal PELD.

Discussion

Full endoscopic lumbar discectomy offers effective nerve root decompression while minimizing disruption to the surrounding soft tissues. This technique may facilitate quicker recovery, preservation of spinal stability, and reduced scar formation, which could collectively enhance long-term outcomes. While the short-term benefits of PELD are increasingly supported by evidence, data describing long-term outcomes remain limited.

Functional outcomes after PELD, assessed using standardized measures such as the VAS and ODI, showed significant improvement from baseline and sustained improvement over time. At 5 or more years postoperatively, the patients consistently reported minimal back and leg pain and low levels of disability. Among the included studies, 87.7% of patients rated their outcomes as good or excellent, suggesting that durable patient satisfaction was achieved. These findings are largely comparable to those reported after minimally invasive microdiscectomy at similar follow-up intervals [26,27], although direct comparisons should be approached with caution because of differences in study design and patient populations. Longitudinal data from open and microdiscectomy cohorts suggest that patient satisfaction may wane over time, particularly as the initial postoperative improvement plateaus and degeneration progresses [28–30]. While a similar trend might be expected after PELD, this review finds no evidence to support this, although high-quality data remains scarce. Additionally, much of the existing literature describing long-term outcomes after discectomy was published more than two decades ago, and any apparent decline in patient-reported outcomes may reflect outdated techniques and perioperative care rather than intrinsic patient progression after discectomy in current practice [31].

Surgical complications following PELD primarily arise in the early postoperative period, with transient neurological deficits, most commonly dysesthesia, being the most prevalent. Several potential causes have been proposed by the authors of the reviewed studies, including inadequate foraminoplasty, reactive nerve root edema, thermal injury, and surgeon inexperience [25]. Although dysesthesia after microdiscectomy is uncommon, it is a well-recognized complication of PELD, particularly after resection of lateral disc herniations, with a reported incidence of 1%–5% [32]. It is typically attributed to dorsal root ganglion irritation during insertion of the transforaminal working cannula or traction on the exiting nerve root [33]. Various technical modifications have been proposed to reduce this risk, although none have fully eliminated it [32–34]. Despite these concerns, dysesthesia is generally mild [33] and self-limited, with only eight instances of persistent deficit identified in this review of >2,000 patients after over 5 years of follow-up. Given this apparent absence of late adverse events, previous meta-analyses suggesting equivalent early complications of PELD and microdiscectomy can likely be relied upon to guide long-term decision-making [7].

Reported recurrence rates following discectomy increase with longer follow-up. Rates of 7.5% at 5 years [35], 8.5% at 8.6 years, and 9.7% at 10 years have been published [36]. A recent nationwide cohort study in the United States confirmed that recurrence is a persistent risk after the early postoperative period, finding a 5-year recurrence rate of 14.4% after primary discectomy and even higher recurrence rates after revision [37]. The pooled recurrence rate after PELD in this series compares favorably with these estimates, being 6.7% at 5 or more years postoperatively. Conventional wisdom states that extensive discectomy reduces the risk of recurrent herniation; therefore, this comparison may be confounded by varying surgeon practice. However, this interpretation has been challenged by numerous investigations reporting the absence of a relationship between the extent of dissection and the risk of recurrent herniation [38]. Elderly patients, smokers, and diabetics have been credibly associated with a greater risk of recurrent herniation, possibly due to the acceleration of the degenerative cascade unrelated to surgery [37,39]. However, the average age of participants included in this review was just 47 years, which likely contributed to a flattering estimate of the long-term recurrence rate. Robust, long-term comparative studies controlling for competing factors are necessary before definitive conclusions can be drawn regarding the comparative risk of recurrence between PELD and conventional techniques.

Long-term radiological outcomes following PELD were infrequently reported, and heterogeneous outcome measures were used, thus preventing a meta-analysis. Qualitatively, current evidence suggests that full endoscopic decompression generally results in minimal disc height loss (approximately 20%). In the two studies reporting segmental ROM, slight reductions were noted at long-term follow-up, suggesting no evidence of long-term instability after PELD based on this metric. Notably, vertebral translations were not described, yet instability could manifest in this area. Minor reductions in disc height are likely an inevitable outcome after discectomy [27]; however, randomized data indicate that greater disc height collapse may occur following more extensive disc resection [40], while lower-quality studies imply that microendoscopic and full endoscopic techniques may better preserve disc height than conventional microdiscectomy in the long term [22,41,42]. Such associations between disc height and surgical technique are at least somewhat confounded by variations in surgeon philosophy and surgical goals. Disc height collapse has been cited as a cause of instability after surgery [3] and has been linked with recurrent disc herniation [43], thus raising the possibility that the modest recurrence rate observed in this synthesis may reflect a relative preservation of intervertebral function.

This study had several limitations. Most included studies were retrospective, introducing potential biases from selective loss to follow-up and incomplete baseline data. Heterogeneity in surgical techniques, outcome definitions, and follow-up durations limits the generalizability of pooled estimates. The observational nature of the data introduced confounding, particularly from the imposition of minimum follow-up periods. If patients lost to follow-up differ meaningfully from those retained, selection bias may occur. In studies that reported loss to follow-up or exclusions for insufficient follow-up, this proportion was consistently under 15%; therefore, these studies may be considered a faithful representation of long-term outcomes. However, four studies did not report this metric, representing a residual source of bias. Small sample sizes in many studies reduce statistical power, although pooling partially mitigates this. Recurrent herniation and reoperation are longitudinal outcomes best assessed using survival analysis; however, the included publications did not provide Kaplan-Meier charts or similar data, which would have allowed for this type of analysis. Eleven articles identified during the literature search were inaccessible, and their exclusion may have affected the results of this study. Subgroup analyses assessing learning curve effects, differences in regional and general anesthesia, transforaminal versus interlaminar techniques, and effects of surgical level are important but were infeasible because of the small number of studies and aggregate level reporting. Perhaps the most relevant unanswered question is how PELD compares to conventional techniques in the long term. However, the near absence of long-term comparative trials limits such assessments to qualitative comparisons, with a high risk of bias and confounding.

Conclusions

This meta-analysis suggests that PELD provides durable symptom relief and a low risk of long-term recurrence, along with favorable functional outcomes. Radiological outcomes also appear acceptable, with modest disc height reduction and no evidence of long-term instability in the limited studies reporting ROM. However, most of the included studies were retrospective and heterogeneous in methodology, introducing a significant risk of bias and limiting the generalizability of the findings. The lack of long-term comparative trials prevents definitive conclusions regarding the relative merits of PELD over other discectomy techniques. Future research should prioritize prospective comparative trials with long-term follow-up to validate these conclusions.

Key Points

Five years or more postoperatively, patients generally report very low pain and disability levels, with nearly nine in 10 rating their outcomes as good or excellent.
Rates of recurrence and reoperation seem modest over the long term, and complications are infrequent and arise early. Radiological follow-up shows only minor disc height loss without evidence of instability in the limited studies reporting flexion-extension range of motion.
The evidence base is limited by the predominance of retrospective studies, differing methods, and a paucity of long-term comparative trials, indicating that the results should be interpreted cautiously.

Notes

Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Author Contributions

Conceptualization: CM, JM. Methodology: CM, JM. Data curation: DK, OS. Formal analysis: CM. Resources: SD, JB. Visualization: JM. Writing–original draft: CM, DK. Writing–review & editing: CM, DK, OS, JM, SD, JB. Final approval of the manuscript: all authors.

References

1. Tumialan LM, Madhavan K, Godzik J, Wang MY. The history of and controversy over Kambin’s triangle: a historical analysis of the lumbar transforaminal corridor for endoscopic and surgical approaches. World Neurosurg 2019;123:402–8. https://doi.org/10.1016/j.wneu.2018.10.221.

2. Lu K, Liang CL, Cho CL, et al. Oxidative stress and heat shock protein response in human paraspinal muscles during retraction. J Neurosurg 2002;97:75–81. https://doi.org/10.3171/spi.2002.97.1.0075.

3. Schaller B. Failed back surgery syndrome: the role of symptomatic segmental single-level instability after lumbar microdiscectomy. Eur Spine J 2004;13:193–8. https://doi.org/10.1007/s00586-003-0632-x.

4. Chen W, Zheng Y, Liang G, Chen G, Hu Y. Clinical effects of transforaminal approach vs interlaminar approach in treating lumbar disc herniation: a clinical study protocol. Medicine (Baltimore) 2020;99:e22701. https://doi.org/10.1097/md.0000000000022701.

5. Ruetten S, Komp M, Merk H, Godolias G. Full-endoscopic interlaminar and transforaminal lumbar discectomy versus conventional microsurgical technique: a prospective, randomized, controlled study. Spine (Phila Pa 1976) 2008;33:931–9. https://doi.org/10.1097/brs.0b013e31816c8af7.

6. Teles P, Pereira P, Silva C, Vaz R, Santos Silva P. Minimally invasive treatment for lumbar disc herniation: a matched comparison between tubular microdiscectomy and percutaneous endoscopic lumbar discectomy. Cureus 2024;16:e57589. https://doi.org/10.7759/cureus.57589.

7. Ruan W, Feng F, Liu Z, Xie J, Cai L, Ping A. Comparison of percutaneous endoscopic lumbar discectomy versus open lumbar microdiscectomy for lumbar disc herniation: a meta-analysis. Int J Surg 2016;31:86–92. https://doi.org/10.1016/j.ijsu.2016.05.061.

8. Gadjradj PS, Rubinstein SM, Peul WC, et al. Full endoscopic versus open discectomy for sciatica: randomised controlled non-inferiority trial. BMJ 2022;376:e065846. https://doi.org/10.1136/bmj-2021-065846.

9. Mooney J, Laskay N, Erickson N, et al. General vs local anesthesia for percutaneous endoscopic lumbar discectomy (PELD): a systematic review and meta-analysis. Global Spine J 2023;13:1671–88. https://doi.org/10.1177/21925682221147868.

10. Koh CH, Booker J, Choi D, et al. Learning curve of endoscopic lumbar discectomy: a systematic review and meta-analysis of individual participant and aggregated data. Global Spine J 2025;15:1435–44. https://doi.org/10.1177/21925682241289901.

11. Kelly A, McNamee C, Deane T, Kelly JG, Kelly D, Blakeney W. Stemless reverse total shoulder arthroplasty: a systematic review and meta-analysis. JSES Rev Rep Tech 2025;5:203–15. https://doi.org/10.1016/j.xrrt.2025.01.003.

12. Valsamis EM, Prats-Uribe A, Koblbauer I, et al. Reverse total shoulder replacement versus anatomical total shoulder replacement for osteoarthritis: population based cohort study using data from the National Joint Registry and Hospital Episode Statistics for England. BMJ 2024;385:e077939. https://doi.org/10.1136/bmj-2023-077939.

13. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71. https://doi.org/10.1136/bmj.n71.

14. NIH Study Quality Assessment Tools [Internet] Bethesda (MD): National Institute of Health; 2021. [cited 2025 Jan 3]. Available from: https://www.nhlbi.nih.gov/health-topics/study-quality-assessment-tools.

15. Puza B, O’neill T. Generalised Clopper–Pearson confidence intervals for the binomial proportion. J Stat Comput Simul 2006;76:489–508. https://doi.org/10.1080/10629360500107527.

16. DerSimonian R, Laird N. Meta-analysis in clinical trials. Control Clin Trials 1986;7:177–88. https://doi.org/10.1016/0197-2456(86)90046-2.

17. Ahn Y, Lee U, Kim WK, Keum HJ. Five-year outcomes and predictive factors of transforaminal full-endoscopic lumbar discectomy. Medicine (Baltimore) 2018;97:e13454. https://doi.org/10.1097/md.0000000000013454.

18. Tang J, Li Y, Wu C, et al. Clinical efficacy of transforaminal endoscopic lumbar discectomy for lumbar degenerative diseases: a minimum 6-year follow-up. Front Surg 2022;9:1004709. https://doi.org/10.3389/fsurg.2022.1004709.

19. Li X, Bai J, Hong Y, et al. Minimum seven-year follow-up outcomes of percutaneous endoscopic lumbar discectomy for lumbar degenerative disease. Int J Gen Med 2021;14:779–85. https://doi.org/10.2147/ijgm.s293400.

20. Li ZZ, Hou SX, Shang WL, Song KR, Zhao HL. Modified percutaneous lumbar foraminoplasty and percutaneous endoscopic lumbar discectomy: instrument design, technique notes, and 5 years follow-up. Pain Physician 2017;20:E85–98. https://doi.org/10.36076/ppj.2017.1.e85.

21. Li Y, Wang B, Li H, et al. Adjuvant surgical decision-making system for lumbar intervertebral disc herniation after percutaneous endoscopic lumber discectomy: a retrospective nonlinear multiple logistic regression prediction model based on a large sample. Spine J 2021;21:2035–48. https://doi.org/10.1016/j.spinee.2021.07.012.

22. Eun SS, Lee SH, Sabal LA. Long-term follow-up results of percutaneous endoscopic lumbar discectomy. Pain Physician 2016;19:E1161–6. https://doi.org/10.36076/ppj/2016.19.e1161.

23. Li T, Zhang J, Ding Z, Jiang Q, Ding Y. Percutaneous endoscopic lumbar discectomy versus open fenestration discectomy for lumbar disc herniation: a retrospective propensity score-matched study with more than 5 years of follow-up. J Orthop Surg Res 2024;19:753. https://doi.org/10.1186/s13018-024-05239-0.

24. Wu C, Lee CY, Chen SC, Hsu SK, Wu MH. Functional outcomes of full-endoscopic spine surgery for high-grade migrated lumbar disc herniation: a prospective registry-based cohort study with more than 5-years of follow-up. BMC Musculoskelet Disord 2021;22:58. https://doi.org/10.1186/s12891-020-03891-1.

25. Tu Z, Li YW, Wang B, et al. Clinical outcome of full-endoscopic interlaminar discectomy for single-level lumbar disc herniation: a minimum of 5-year follow-up. Pain Physician 2017;20:E425–30. https://doi.org/10.36076/ppj.2017.e430.

26. Aichmair A, Du JY, Shue J, et al. Microdiscectomy for the treatment of lumbar disc herniation: an evaluation of reoperations and long-term outcomes. Evid Based Spine Care J 2014;5:77–86. https://doi.org/10.1055/s-0034-1386750.

27. Rahme R, Moussa R, Bou-Nassif R, et al. Lumbar microdiscectomy: a clinicoradiological analysis of outcome. Can J Neurol Sci 2011;38:439–45. https://doi.org/10.1017/s0317167100011847.

28. Salenius P, Laurent LE. Results of operative treatment of lumbar disc herniation: a survey of 886 patients. Acta Orthop Scand 1977;48:630–4. https://doi.org/10.3109/17453677708994809.

29. Dvorak J, Gauchat MH, Valach L. The outcome of surgery for lumbar disc herniation. I. A 4–17 years’ follow-up with emphasis on somatic aspects. Spine (Phila Pa 1976) 1988;13:1418–22. https://doi.org/10.1097/00007632-198812000-00015.

30. Findlay GF, Hall BI, Musa BS, Oliveira MD, Fear SC. A 10-year follow-up of the outcome of lumbar microdiscectomy. Spine (Phila Pa 1976) 1998;23:1168–71. https://doi.org/10.1097/00007632-199805150-00019.

31. Wong T, Patel A, Golub D, et al. Prevalence of long-term low back pain after symptomatic lumbar disc herniation. World Neurosurg 2023;170:163–73. https://doi.org/10.1016/j.wneu.2022.11.029.

32. Cho JY, Lee SH, Lee HY. Prevention of development of postoperative dysesthesia in transforaminal percutaneous endoscopic lumbar discectomy for intracanalicular lumbar disc herniation: floating retraction technique. Minim Invasive Neurosurg 2011;54:214–8. https://doi.org/10.1055/s-0031-1287774.

33. Kim HS, Kim JY, Wu PH, Jang IT. Effect of dorsal root ganglion retraction in endoscopic lumbar decompressive surgery for foraminal pathology: a retrospective cohort study of interlaminar contralateral endoscopic lumbar foraminotomy and discectomy versus transforaminal endoscopic lumbar foraminotomy and discectomy. World Neurosurg 2021;148:e101–14. https://doi.org/10.1016/j.wneu.2020.12.176.

34. Fiorenza V, Ascanio F. Percutaneous endoscopic transforaminal outside-in outside technique for foraminal and extraforaminal lumbar disc herniations: operative technique. World Neurosurg 2019;130:244–53. https://doi.org/10.1016/j.wneu.2019.07.005.

35. Hakkinen A, Kiviranta I, Neva MH, Kautiainen H, Ylinen J. Reoperations after first lumbar disc herniation surgery; a special interest on residives during a 5-year follow-up. BMC Musculoskelet Disord 2007;8:2. https://doi.org/10.1186/1471-2474-8-2.

36. Yorimitsu E, Chiba K, Toyama Y, Hirabayashi K. Long-term outcomes of standard discectomy for lumbar disc herniation: a follow-up study of more than 10 years. Spine (Phila Pa 1976) 2001;26:652–7. https://doi.org/10.1097/00007632-200103150-00019.

37. Etigunta SK, Liu AM, Gausper A, et al. Long-term reoperation rates after single-level lumbar discectomy: a nationwide cohort study. Spine (Phila Pa 1976) 2025;50:1052–7. https://doi.org/10.1097/brs.0000000000005328.

38. Ambrosio L, Vadala G, de Rinaldis E, et al. Discectomy versus sequestrectomy in the treatment of lumbar disc herniation: a systematic review and meta-analysis. Spine J 2025;25:211–26. https://doi.org/10.1016/j.spinee.2024.09.007.

39. Abdel-Fattah AR, Irving A, Baliga S, Myint PK, Martin KR. How to spot the recurring lumbar disc?: risk factors for recurrent lumbar disc herniation (rLDH) in adult patients with lumbar disc prolapse: a systematic review and meta-analysis. Acta Orthop Belg 2023;89:381–92. https://doi.org/10.52628/89.3.11201.

40. Barth M, Diepers M, Weiss C, Thome C. Two-year outcome after lumbar microdiscectomy versus microscopic sequestrectomy: part 2: radiographic evaluation and correlation with clinical outcome. Spine (Phila Pa 1976) 2008;33:273–9. https://doi.org/10.1097/brs.0b013e31816201a6.

41. Song Z, Ran M, Luo J, et al. Follow-up results of microendoscopic discectomy compared to day surgery using percutaneous endoscopic lumbar discectomy for the treatment of lumbar disc herniation. BMC Musculoskelet Disord 2021;22:160. https://doi.org/10.1186/s12891-021-04038-6.

42. Wang M, Zhou Y, Wang J, Zhang Z, Li C. A 10-year follow-up study on long-term clinical outcomes of lumbar microendoscopic discectomy. J Neurol Surg A Cent Eur Neurosurg 2012;73:195–8. https://doi.org/10.1055/s-0031-1297248.

43. Kim KT, Park SW, Kim YB. Disc height and segmental motion as risk factors for recurrent lumbar disc herniation. Spine (Phila Pa 1976) 2009;34:2674–8. https://doi.org/10.1097/brs.0b013e3181b4aaac.

Article information Continued

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Author	Year	LOE	NIH	Approach	Patients	Excluded FU (%)^a)	Age (yr)	Male (%)	FU (yr)	Outcomes reported^b)
Retrospective investigations
Ahn et al. [17]	2018	IV	Good	TF	204	10.9	32.9	53.4	5.0^c)	1, 2, 3, 5, 8, 9, 10
Tang et al. [18]	2022	IV	Fair	TF	64	12.3	57.7	43.8	6.0^c)	2, 3, 4, 6, 7, 8, 9, 10
Eun et al. [22]	2016	IV	Poor	35/38 TF; 3/38 IL	38^d)	NR	53.7	63.2	11.2	1, 2, 3, 6, 9, 10
Li et al. [23]	2024	III	Poor	TF & IL	51	NR	40.3	80.4	8.1	1, 2, 3, 4, 5, 6, 7, 8, 9
Tu et al. [25]	2017	III	Poor	IL	72	NR	38.3	55.6	6.2	1, 2, 3, 5, 8, 9
Li et al. [19]	2021	IV	Fair	TF	42	12.5	48.6	57.1	8.0	1, 2, 3, 4, 5, 6, 8, 9, 10
Li et al. [21]	2021	IV	Good	TF	1,706	5.6	47.0	59.0	6.4	9
Wu et al. [24]	2021	III	Poor	IL	17	NR	55.2	35.3	5.7	1, 2, 3, 5, 9, 10
				TF	41	NR	56.7	34.1	6.3
Prospective investigations
Li et al. [20]	2017	II	Good	TF	134	9.5	41.4	50.7	5.0	1, 2, 3, 5, 8, 9, 10

Outcome	No. of studies	Preoperative	Improvement	At follow-up
VAS (leg)	8	6.40±2.36	5.29±2.08	1.11±0.64
ODI	8	58.31±12.52	46.30±4.69	12.01±4.69
VAS (back)	7	4.15±2.10	2.95±1.57	1.21±0.77
Modified MacNab criteria	6	-	-	0.90±0.05
JOA	3	10.24±2.35	14.52±2.34	24.76±1.24