Comparison of recurrence and postoperative outcomes after endoscopic versus microsurgical sequestrectomy for lumbar disc herniation: 5-year experience

Introduction

Endoscopic techniques in spinal surgery are gaining increasing importance. Currently, not only standard procedures for intervertebral disc herniations and spinal stenosis can be performed endoscopically, but also more complex operations, such as cage implantation [e.g., percutaneous endoscopic transforaminal lumbar interbody fusion (PE-TLIF)] (1) or decompression for Chiari malformations (2,3). Surgical expertise continues to expand, optical systems and instruments are constantly improving, and new navigation technologies are being introduced. Despite these advances, endoscopic techniques still have several limitations that restrict their broader application.

Both percutaneous endoscopic sequestrectomy (PES) or percutaneous endoscopic discectomy (PED), and open microsurgical sequestrectomy (OMS) or open microsurgical discectomy (OMD), are widely used surgical treatments for lumbar disc herniation (LDH) and are generally considered safe and effective. Across the literature, long-term clinical outcomes appear broadly comparable between techniques with respect to pain reduction, functional improvement, and recurrence-related endpoints. Evidence from systematic reviews and randomized controlled trials (RCTs) suggests no clinically meaningful differences in patient-reported measures such as leg pain, low back pain, and Oswestry Disability Index (ODI), and overall complication profiles—including recurrence and reoperation—are also similar in many comparative series (4-9).

OMS remains a well-established reference technique supported by extensive long-term data and a familiar safety profile. Endoscopic approaches, however, are often associated with less perioperative tissue disruption, shorter hospitalization, faster postoperative recovery, and more favorable cosmetic outcomes, although they typically require dedicated equipment and specific surgeon training. Overall, both approaches represent valid options, and selection is usually individualized based on surgeon experience, patient factors and preferences, anatomical considerations, and local resources (4-10).

One of the most common complications after surgery for LDH is recurrence, defined as a new LDH at the same spinal level and on the same side following the index procedure, occurring after an initial postoperative improvement of the preoperative symptoms. Some authors vary this definition to include a new LDH at the same level on the contralateral side as well (3). Published series report a wide range of recurrence rates after surgery for LDH, from 0.5% to 21%. Reported same-side, same-level recurrences are more narrowly distributed, typically around 1.4% to 11.4%. Importantly, re-operation rates are not equivalent to recurrence rates and have been reported between 5.2% and 19%, with higher values generally observed with longer follow-up; for example, reoperation rates have been described as approximately 0.5% at 1 year and rising to about 2.8% at 15 years after surgery (3,11-18).

Multiple factors have been investigated in relation to recurrence rates and recurrence risk, including surgical technique. Over the last two decades, endoscopic and minimally invasive procedures have gained a wide spectrum of applications in spinal surgery, and minimally invasive spine surgery (MISS) is increasingly considered a standard approach for the treatment of LDH. To compare “open” techniques with minimally invasive ones, multiple studies have been conducted in recent years. A meta-analysis including nine relevant RCTs involving 1,092 patients identified similar recurrence rates between PED and OMD. The recurrence rates of the PED group and OMD group were 5.04% and 3.35%, respectively. The reoperation rates of the PED group and OMD group were 6.82% and 6.93%, respectively (19).

Nevertheless, these methods differ in several important aspects. One of the main differences is that the microsurgical approach allows the surgeon to use more than one instrument simultaneously, which often facilitates better mobilization of the sequestrum, especially in technically unfavorable positions (for example, near the nerve root origin). However, endoscopic techniques may be more suitable in cases where surgical access itself represents a major challenge, such as in patients with extreme obesity (20). Thus, prospective randomized studies do not fully answer the key question of selecting the optimal method for an individual patient. We believe that indication selection should be based on multiple factors, including the location of the herniation, its chronicity (acute or chronic), neurological symptomatology, and patient-specific anatomical characteristics.

We present the 5-year experience of our clinic in order to discuss indications for endoscopic techniques and specific aspects of patient management. We present this article in accordance with the TREND reporting checklist (available at https://jss.amegroups.com/article/view/10.21037/jss-2026-0147/rc).

Methods

A total of 187 patients underwent surgical treatment by PES or OMS for LDH between September 2019 and November 2022, with a follow-up of at least 2.5 years. All procedures were performed by our four staff surgeons. OMS was performed via laminotomy or hemilaminectomy, depending on case-specific considerations. PES was performed either via transforaminal percutaneous endoscopic sequestrectomy (TPES) or interlaminar percutaneous endoscopic sequestrectomy (IPES), based on case-specific considerations.

Recurrence was defined as a new LDH at the same spinal level and on the same side after the index surgery, occurring after postoperative relief of the preoperative symptoms, without a specified minimum time interval. All recurrences included in this study were clinically suspected based on recurrent symptoms and confirmed by MRI. Reoperation was indicated in symptomatic recurrent cases with new paresis, therapy-resistant radicular pain, and/or cauda equina/conus medullaris symptoms. Therefore, cases requiring reoperation after recurrence were defined as recurrence requiring reoperation (RrR). Conservatively treated recurrences were not included in the recurrence analysis, because all recurrence cases required reoperation and were therefore classified as RrR.

Statistical analysis

All categorical variables were analyzed using Fisher’s exact test, with the exception of surgical segment, which was analyzed using the chi-square test. All continuous variables were analyzed using Welch’s t-test. A P value <0.05 was considered statistically significant. P values were not adjusted for multiple comparisons. Effect estimates with 95% confidence intervals (CIs) were reported where appropriate. Mean differences (MDs) were used for continuous variables, and risk differences (RDs) were used for categorical variables. A multivariable Cox proportional hazards regression was performed, including surgical technique, age, symptom duration <3 months, and grouped surgical segment as covariates. Recurrence-free survival was analyzed using Kaplan-Meier curves and compared between groups using the log-rank test. Cox proportional hazards regression was used to estimate hazard ratios with 95% CIs. All analyses were performed using R for OS, Version 4.5.2 (R Foundation for Statistical Computing, Vienna, Austria). This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Due to the retrospective nature of the study, ethics committee approval was not required. The study involved the retrospective analysis of anonymized data obtained during routine clinical practice, in accordance with institutional regulations. Informed consent was therefore not required.

Results

Baseline characteristics

Patients in the PES group were significantly younger than those in the OMS group (47.15±14.12 vs. 53.03±14.31 years; MD −5.88, 95% CI: −10.63 to −1.13; P=0.02). Sex distribution was comparable between groups, with 53% males in the PES group and 60% in the OMS group (RD −6.8%, 95% CI: −28.5% to 14.9%; P=0.49). Symptom duration <3 months was more frequent in the PES group (95.7% vs. 80.7%; RD 15.0%, 95% CI: −0.6% to 25.4%; P=0.01). Radicular pattern differed significantly between groups (P<0.001), with absence of radicular pain observed only in the PES group (14.9% vs. 0.0%; RD 14.9%, 95% CI: 4.7–27.7%). Surgical segment distribution also differed significantly between groups (P<0.001), with PES more frequently performed at L5–S1 (57.4% vs. 29.3%; RD 28.2%, 95% CI: 6.0–48.1%), whereas OMS was more frequently performed at L4–5 (23.4% vs. 51.4%; RD −28.0%, 95% CI: −46.0% to −6.0%). Rates of hypoesthesia/paraesthesia were similar (89.4% vs. 91.4%; RD −2.1%, 95% CI: −17.6% to 9.8%; P=0.77), as were rates of paresis (34.0% vs. 48.6%; RD −14.5%, 95% CI: −34.6% to 7.9%; P=0.09), urinary and/or fecal incontinence (6.4% vs. 1.4%; RD 5.0%, 95% CI: −2.9% to 16.8%; P=0.10), and cauda equina/conus medullaris syndrome (8.5% vs. 3.6%; RD 4.9%, 95% CI: −4.7% to 18.4%; P=0.23). Laterality was comparable between groups (right: 48.9% vs. 50.7%; RD −1.8%, 95% CI: −23.6% to 20.2%; P=0.87). Previous surgery at the same level was observed only in the OMS group (0.0% vs. 8.6%; RD −8.6%, 95% CI: −14.4% to 2.6%; P=0.04) (Table 1).

Perioperative and clinical outcomes

Postoperative reduction of pain/symptoms was high in both groups but was slightly lower after PES compared with OMS (93.6% vs. 99.3%; RD −5.7%, 95% CI: −17.0% to 1.7%; P=0.050). Discectomy was performed exclusively in the OMS group (57.1% vs. 0.0%; RD −57.1%, 95% CI: −65.0% to −41.3%; P<0.001). Dural tears occurred only in the OMS group (2.9% vs. 0.0%; RD −2.9%, 95% CI: −7.1% to 6.4%; P=0.57). Operative time was significantly shorter in the PES group (84.74±37.16 vs. 122.89±41.39 minutes; MD −38.15, 95% CI: −50.97 to −25.33; P<0.001), whereas length of hospital stay was comparable (4.34±1.88 vs. 4.65±2.02 days; MD −0.31, 95% CI: −0.95 to 0.33; P=0.34).

The overall complication rate did not differ significantly between PES and OMS (21.3% vs. 12.1%; RD 9.1%, 95% CI: −6.6% to 27.2%; P=0.15). Recurrence rates were numerically higher after PES (12.8% vs. 7.1%; RD 5.6%, 95% CI: −6.7% to 21.2%), but this difference was not statistically significant (P=0.24). All recurrences required operative management, i.e., RrR. Neuropathic pain was more frequent after PES (8.5% vs. 1.4%; RD 7.1%, 95% CI: −1.7% to 19.5%; P=0.04), while wound infection, root injury, cerebrospinal fluid (CSF) fistula, postoperative hematoma, and instability were rare and showed no significant between-group differences (all P≥0.44). Reoperation rates for first recurrence were identical to the recurrence rates (12.8% vs. 7.1%; RD 5.6%, 95% CI −6.7% to 21.2%; P=0.24), and time to first recurrence among recurrent cases was similar between groups (7.56±5.56 vs. 5.14±5.56 months; MD 2.42, 95% CI: −3.92 to 8.76; P=0.42). Reoperation for second recurrence was uncommon (4.3% vs. 1.4%; RD 2.8%, 95% CI: −3.9% to 13.9%; P=0.26), and time to second recurrence did not differ significantly (6.50±7.78 vs. 5.50±0.71 months; MD 1.00, 95% CI: −66.53 to 68.53; P=0.89). Mean follow-up duration was comparable between groups (51.02±7.63 vs. 50.35±11.06 months; MD 0.67, 95% CI: −2.21 to 3.55; P=0.65) (Table 2).

Time-to-event analysis

In the exploratory multivariable Cox regression adjusted for age, symptom duration <3 months, and grouped surgical segment, PES was associated with a numerically higher hazard of recurrence compared with OMS, although this association was not statistically significant [hazard ratio (HR) 1.98, 95% CI: 0.65–5.98; P=0.23]. Age was not associated with recurrence risk (HR 1.00 per 1-year increase, 95% CI: 0.96–1.04; P=0.95). Symptom duration <3 months was also not significantly associated with recurrence-free survival (HR 0.64, 95% CI: 0.17–2.40; P=0.51). Compared with L4–5, neither L5–S1 (HR 1.03, 95% CI: 0.31–3.45; P=0.96) nor upper lumbar levels (HR 1.54, 95% CI: 0.42–5.70; P=0.52) were significantly associated with recurrence (Table 3).

Kaplan-Meier analysis showed no significant difference in recurrence-free survival between PES and OMS (log-rank χ²=1.36, P=0.24). At 12 months, recurrence-free survival was 87.2% in the PES group and 94.3% in the OMS group. At 24 months, recurrence-free survival was 87.2% after PES and 92.9% after OMS, remaining unchanged at 60 months. Median recurrence-free survival was not reached in either group (Table 4).

Discussion

In this single-center cohort with a minimum follow-up of 2.5 years, both PES and OMS provided high rates of postoperative symptom improvement. Overall, our findings support the concept highlighted in the Introduction that endoscopic and microsurgical techniques represent established and effective options for LDH, with broadly comparable long-term clinical outcomes in many settings. At the same time, our data underscore that these approaches differ in relevant perioperative and complication-related aspects and that patient selection remains critical.

Comparison with current evidence

A recent systematic review and meta-analysis published in 2026, including randomized trials and cohort studies, reported no clinically relevant differences between endoscopic discectomy and microdiscectomy regarding leg pain, back pain, and ODI across short-, mid-, and long-term follow-up (21). In our cohort, postoperative symptom reduction was also high in both groups, although it was slightly lower after PES compared with OMS (93.6% vs. 99.3%; RD −5.7%, 95% CI: −17.0% to 1.7%; P=0.050). This borderline difference should be interpreted cautiously, as symptom improvement was assessed as a binary outcome in our dataset rather than by validated patient-reported outcome measures (PROMs) such as ODI or visual analogue scale (VAS), which limits direct comparability with the meta-analysis and with the broader literature.

With respect to operative parameters, the literature found no clinically significant difference in operative time between endoscopic discectomy and microsurgical discectomy (21,22), whereas operative time was substantially shorter after PES in our series (84.74±37.16 vs. 122.89±41.39 minutes; MD −38.15 minutes, 95% CI: −50.97 to −25.33; P<0.001). This discrepancy may reflect differences in technique definitions (sequestrectomy vs. discectomy), institutional workflow, surgeon experience, and case selection. Notably, discectomy was performed exclusively in the OMS group (57.1% vs. 0.0%; RD −57.1%, 95% CI: −65.0% to −41.3%; P<0.001) in our study, which likely contributed to longer operative duration in OMS and represents an important procedural difference between groups.

Lenght of stay (LOS) was comparable in our cohort (4.34±1.88 vs. 4.65±2.02 days; MD −0.31 days, 95% CI: −0.95 to 0.33; P=0.34). This contrasts with the recent evidence, which reported significantly shorter LOS after endoscopic discectomy. As also already emphasized in the literature, LOS is influenced not only by surgical invasiveness but also by local discharge pathways, health-system structures, and regional practice patterns. Therefore, LOS differences are not necessarily generalizable across health-care settings (21,22).

Recurrence and reoperation

Recurrence remains one of the most relevant outcomes after LDH surgery. In our cohort, recurrence rates were numerically higher after PES than OMS (12.8% vs. 7.1%; RD 5.6%, 95% CI −6.7% to 21.2%), although this did not reach statistical significance (P=0.24). These findings align in direction with current literature (11-19,21). The wide CI and lack of statistical significance suggest that this finding should be interpreted cautiously, particularly given the limited number of recurrence events.

Because recurrence is a time-dependent event, we additionally performed Kaplan-Meier recurrence-free survival analysis and Cox regression. Kaplan-Meier analysis showed no significant difference in recurrence-free survival between PES and OMS (log-rank χ²=1.36, P=0.24). At 12 months, recurrence-free survival was 87.2% after PES and 94.3% after OMS; at 24 and 60 months, recurrence-free survival remained 87.2% after PES and 92.9% after OMS. In exploratory multivariable Cox regression adjusted for age, symptom duration <3 months, and grouped surgical segment, PES was associated with a numerically higher hazard of recurrence compared with OMS, although this association was not statistically significant (HR 1.98, 95% CI: 0.65–5.98; P=0.23). These additional analyses support the interpretation that recurrence-related outcomes were not statistically different between groups, while also highlighting the uncertainty caused by the small number of events.

Importantly, our recurrence definition was clinically strict in that all recurrences required operative management and were therefore classified as RrR. This may contribute to differences in absolute recurrence rates across studies, given the heterogeneity of recurrence definitions in the literature, including imaging-confirmed recurrence, symptomatic recurrence, and recurrence requiring surgery, as well as differences in follow-up duration.

From a mechanistic perspective, recurrence risk may be influenced by the extent of disc removal. Endoscopic sequestrectomy often emphasizes targeted fragment removal with preservation of disc tissue, whereas microsurgical procedures may more frequently include disc space exploration and additional disc removal. In our cohort, the procedural difference is reflected in the variable “discectomy performed”, which occurred only in OMS. Although such strategies may reduce residual fragment risk in some cases, they may also have different implications for postoperative back pain and disc degeneration. The optimal balance between targeted sequestrectomy and more extensive discectomy remains debated and is likely influenced by herniation morphology, annular defect size, chronicity, and segment-specific anatomy.

Complications

The overall complication rate did not differ significantly between PES and OMS (21.3% vs. 12.1%; RD 9.1%, 95% CI: −6.6% to 27.2%; P=0.15), which is consistent with the reported complication rates between endoscopic discectomy and microsurgical discectomy (11-19,21). In our data, dural tears occurred only in OMS (2.9% vs. 0.0%; RD −2.9%, 95% CI: −7.1 to 6.4; P=0.57). Wound complications were rare in our cohort, limiting meaningful comparative inference; nevertheless, the 2026 meta-analysis reported significantly lower wound complications after ED, which remains a plausible advantage of less invasive soft-tissue exposure (21).

A notable finding in our series was the higher rate of neuropathic pain after PES (8.5% vs. 1.4%; RD 7.1%, 95% CI: −1.7% to 19.5%; P=0.04). This may reflect irritation of the dorsal root ganglion or exiting nerve root during endoscopic access, particularly in transforaminal trajectories, as well as the effects of working channel manipulation and irrigation. However, given the small number of events, this result should be interpreted cautiously and ideally validated in larger datasets with standardized postoperative neuropathic pain assessment.

Baseline differences, selection effects, and limitations

Several clinically relevant baseline imbalances were present between groups, including younger age and shorter symptom duration in the PES group, different surgical level distribution, and previous surgery at the same level only in the OMS group. These differences may confound comparisons of recurrence and complications, as level, chronicity, and revision status can influence surgical complexity and recurrence risk. Although an exploratory multivariable Cox regression was performed to adjust for age, symptom duration, and grouped surgical segment, only 16 recurrence events occurred; therefore, this analysis should be interpreted cautiously and cannot fully exclude residual confounding.

Procedural heterogeneity should also be considered. Discectomy was performed in 57.1% of OMS cases but in none of the PES cases; thus, this study reflects real-world institutional treatment strategies rather than a pure comparison of surgical access alone. A reliable subgroup analysis of sequestrectomy versus discectomy was not feasible because all discectomy cases occurred in the OMS group and the number of recurrence events was limited.

Clinical outcomes were assessed based on documented postoperative symptom reduction, but validated PROMs such as ODI or VAS were not routinely available. Therefore, direct comparison with studies using standardized PROMs is limited. Overall, the present findings should be interpreted as observational and exploratory rather than definitive estimates of technique-specific effects.

Conclusions

Taken together, our experience supports the view that both PES and OMS are valid approaches for LDH, with broadly similar clinical effectiveness. PES offered a substantial reduction in operative time in our setting, while recurrence showed a nonsignificant numerical increase and neuropathic pain occurred more frequently after PES. These findings reinforce the need for careful patient selection and technique tailoring based on herniation level, morphology and chronicity, neurological status, prior surgery, and surgeon expertise. Prospective studies with standardized PROMs and adequately powered recurrence analyses are warranted to clarify technique-specific risks and benefits in well-defined LDH subgroups.

The choice of surgical approach in the treatment of intervertebral disc herniation should be patient-oriented. The primary goal must be the improvement of clinical symptomatology and minimization of complications.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the TREND reporting checklist. Available at https://jss.amegroups.com/article/view/10.21037/jss-2026-0147/rc

Data Sharing Statement: Available at https://jss.amegroups.com/article/view/10.21037/jss-2026-0147/dss

Peer Review File: Available at https://jss.amegroups.com/article/view/10.21037/jss-2026-0147/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jss.amegroups.com/article/view/10.21037/jss-2026-0147/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Due to the retrospective nature of the study, ethics committee approval was not required. The study involved the retrospective analysis of anonymized data obtained during routine clinical practice, in accordance with institutional regulations. Informed consent was therefore not required.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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