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Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy
Journal of Clinical Neuroscience xxx (xxxx) xxx
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Clinical study
Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy Yunhee Choi a, Chi Heon Kim b,c,d,e,⇑, John M. Rhee e, Calvin C. Kuo f, Urim Lee g, Sung Bae Park b,c,d,h, Chang-Hyun Lee b,c,d, Seung Heon Yang b,c,d, Kyoung-Tae Kim i,j, Chun Kee Chung b,c,d,g,k a
Medical Research Collaborating Center, Seoul National University Hospital, 101 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea Department of Neurosurgery, Seoul National University College of Medicine, 103 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea Department of Neurosurgery, Seoul National University Hospital, 101 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea d Clinical Research Institute, Seoul National University Hospital, 101 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea e Department of Orthopaedic Surgery and Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA f Regional Spine Surgery Department, Kaiser Permanente, 3600 Broadway, Suite 15, Oakland, CA 94611, USA g Human Brain Function Laboratory, Department of Neurosurgery, Seoul National University Hospital, 101 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea h Department of Neurosurgery, Seoul National University Boramae Hospital, Borame Medical Center 20, Boramae-ro 5-gil, Dongjak-gu, Seoul 07061, South Korea i Department of Neurosurgery, Kyungpook National University Hospital, 130 Dongdeok-ro, Jung-gu, Daegu 41944, South Korea j Department of Neurosurgery, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 41944, South Korea k Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea b c
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Article history: Received 14 September 2019 Accepted 20 December 2019 Available online xxxx Keywords: Lumbar vertebrae Pain Endoscopic discectomy Recurrence Spine Surgery Treatment outcome
a b s t r a c t Objective: Full-endoscopic lumbar discectomy (FELD) is a minimally invasive surgical option for recurrent lumbar disc herniation (LDH). Nonetheless, patients’ clinical outcomes may be poorer after surgery for recurrent LDH than for primary LDH. Therefore, we compared patients’ longitudinal clinical outcomes after FELD for recurrent LDH or primary LDH. Methods: The medical records of patients who underwent FELD for primary LDH (group A) or recurrent LDH (group B) were retrospectively reviewed. The inclusion criteria were: 1) single-level LDH or recurrent LDH at L4-5 or L5-S1, 2) age 60 years, 3) previous open discectomy (group B), and 4) 6 months of follow-up. In total, 244 patients (group A, 211; group B, 33) were included. Clinical outcomes (Oswestry Disability Index [ODI]; visual analogue pain score for the back and leg [VAS-B] and [VAS-L]) over 24 months of follow-up were compared between groups with a linear mixed-effects model. Results: All clinical outcomes significantly improved from pre-operation to 3 months postoperatively (p < 0.01), and the improvement was maintained for 24 months postoperatively in both groups. The clinical outcomes of groups A and B were not significantly different during 24 months follow-up (ODI, p = 0.94; VAS-B, p = 0.11; and VAS-L, p = 0.48). The reoperation rate was 3.3% in group A and 3.0% in group B, but the overall complication rate was higher in group B (9.8%) than in group A (6.6%). Conclusion: The longitudinal clinical outcomes after FELD for recurrent LDH may not be poor as feared. However, the higher complication rate in patients undergoing FELD for recurrent LDH should be noted. Ó 2019 Elsevier Ltd. All rights reserved.
1. Introduction Recurrent lumbar disc herniation (LDH), which is a major concern after surgery for primary LDH, occurs in approximately 10% of patients [1–3]. Non-surgical modalities such as medications, physiotherapy, or interventional injections are first-line treatments for recurrent LDH, but surgical treatment is considered if
⇑ Corresponding author: Department of Neurosurgery, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-gu, Seoul 110-744, South Korea. E-mail address: [email protected] (C.H. Kim).
those treatments are not effective for 6 weeks, pain is incapacitating, or substantial motor weakness is present [1]. However, revision discectomy is more complex than primary surgery because of scar formation, progressed disc degeneration, and the higher likelihood of less satisfactory clinical outcomes and re-recurrence [4–8]. Some authors advocate fusion surgery due to those issues, but fusion surgery has been associated with a longer surgical time, longer hospital stay, higher hospital costs, and higher rates of surgery-related complications than nonfusion discectomy [1,9–13]. A systematic review showed that clinical outcomes such as functional disability, low back pain, and leg
https://doi.org/10.1016/j.jocn.2019.12.047 0967-5868/Ó 2019 Elsevier Ltd. All rights reserved.
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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pain were not significantly different between patients who underwent discectomy with fusion and those who underwent discectomy without fusion, and excellent or good surgical outcomes were achieved in more than 80% of patients without fusion surgery [8,11–14]. For those reasons, non-fusion surgery was chosen for 77% of patients in a population-based study, and revision discectomy remains a viable surgical option [1,6,12,15–18]. More recently, full-endoscopic lumbar discectomy (FELD) has been utilized for recurrent LDH, with comparable results to open discectomy [5,9,19–23]. The advantages of FELD for recurrent LDH include a short hospital stay, minimal tissue injury, and less need to go through scar tissue; therefore, FELD may be an alternative surgical technique [3,13,21]. Nonetheless, there are concerns that most patients may experience poorer longitudinal clinical outcomes with time and that outcomes may be poorer after surgery for recurrent LDH than for primary LDH. In this context, we investigated patients’ longitudinal clinical outcomes after FELD for recurrent LDH in comparison with those after FELD for primary LDH.
ments were removed using forceps. In group A, fragmentectomy of the herniated disc and removal of loose disc fragments under the herniated disc were generally sufficient because they had small annular defects [7,21,24,25,29]. However, more extensive removal of loose disc fragments was sometimes necessary in group B, because more disc material may remain in the setting of an large annular defect [7,15,29]. For IL, an 8-mm skin incision was made at the skin above the interlaminar space, and the dilator and working tube were sequentially introduced. The ligamentum flavum was opened for primary LDH, and the ruptured disc and all graspable loose disc fragments were removed using forceps or flexible forceps. For recurrent LDH, the scar tissue was dissected from the medial facet joint with a working tube, and the scar tissue and the neural tissue were retracted together with the working tube [19,26]. The ruptured disc and all graspable loose disc fragments were removed using forceps. A larger amount of loose disc fragments was removed for recurrent LDH than for primary LDH. The working tube and endoscope were pulled out after confirmation of decompression and hemostasis, and the skin was closed using 3–0 Nylon sutures.
2. Materials and methods 2.1. Materials
2.3. Postoperative management
Since 2005, all clinical and radiological data for patients undergoing FELD were prospectively recorded using an electronic medical records system (IRB No. 0507-509-153) [24,25]. Informed consent was obtained from all patients. After approval from our institutional review board (IRB No. 1611-015-803), the prospectively collected medical records were retrospectively reviewed for patients who underwent FELD from 2009 to 2016. FELD was indicated when symptomatic primary LDH or recurrent LDH was incapacitating for more than 6 weeks with non-surgical treatment, or neurological weakness (manual motor power of less than 3 out of 5) was present [24,25]. We selected patients according to the following inclusion criteria: 1) single-level LDH or recurrent LDH at L4-5 or L5-S1, 2) age 60 years, 3) symptomatic primary LDH or recurrent LDH verified with magnetic resonance imaging, 4) previous history of open discectomy for patients with recurrent LDH, 5) absence of spinal stenosis at any level, 6) absence of a psychiatric or neuromuscular diagnosis, such as depression or Parkinson disease, and 7) a follow-up period longer than 6 months [24,25]. A total of 244 patients (group A, FELD for primary LDH, 211; group B, FELD for recurrent LDH, 33) were included in the present study (Fig. 1).
The preoperative and postoperative management protocols were the same in all patients. Patients were encouraged to ambulate on the day of surgery and all patients were discharged the next day if their symptoms had improved [24–26]. Patients were scheduled to visit the clinic at 3, 6, and 12 months postoperatively and yearly thereafter. Additionally, patients were encouraged to visit an outpatient clinic at any time when they experienced intractable pain. Patients were asked to fill out patient-reported-outcome questionnaires, including the Korean version of the Oswestry Disability Index (K-ODI, x/45) and visual analogue pain scores for the back (VAS-B, x/10) and leg (VAS-L, x/10) on each clinic visit day [30,31]. The median follow-up period was 24.2 months (range, 6–81) for group A and 24.4 months (range, 6–62) for group B.
2.2. Surgical techniques Standard surgical techniques were used in both groups [7,19– 22,24–27]. The selection of the surgical approach was the same for both groups; primarily, a transforaminal approach (TF) was used for L4-5 and an interlaminar approach (IL) for L5-S1 [24– 26]. IL was preferred for patients with high-grade superior or inferior migrated LDH at any level, an LDH exhibiting high-grade (>50%) canal compromise, or a high iliac crest [20,24–26,28]. All operations were done with the patient in the prone position under general anesthesia, fluoroscopic guidance, and electromyographic monitoring. The basic surgical techniques of TF and IL were as follows. For TF, an 18-gauge needle was inserted from the symptomatic side aiming at the neural foramen of the disc herniation under fluoroscopic guidance. A guidewire was inserted, and an 8mm skin incision was made. The dilator and the working tube were sequentially introduced. An endoscope (Vertebris system; RIWOspine GmbH, Knittlingen, Germany) was introduced after the dilator was removed. The ruptured disc and all graspable loose disc frag-
2.4. Statistical analysis Continuous and non-continuous values were compared using the t-test and chi-square test (or the Fisher exact test), respectively, and using the standardized difference. Since the sample size was small, the confounders for comparisons of clinical outcomes (K-ODI, VAS-B and VAS-L) were determined considering p-values <0.1 and a standardized difference >0.2. Clinical outcomes were longitudinally compared between group A and group B for 24 months with a linear mixed-effects model. The random effect was the subjects. The fixed effects included group, time, the interaction between group and time, the baseline values of clinical outcomes, and confounders. The factors considered as confounders were age, sex, duration of recent symptoms, body mass index (kg/m2), smoking status (yes vs. no), surgical level, side of symptom, disc type (bulging/protrusion vs. extrusion/sequestration) [32], high-grade canal compromise by the LDH (>50% of the spinal canal) [20,33], high-grade migration [20,34], disc degeneration (Pfirrmann grade at the index level [grade 1–3 vs. 4–5]) [35,36], the presence of Modic changes (yes vs. no), and the surgical approach (TF vs IL) [37]. A post hoc analysis was planned using the stepdown Bonferroni method to test the changes between the preoperative and postoperative (3, 6, 12, and 24 months) time points. All statistical analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC, USA). Statistical significance was defined as p < 0.05 (2-sided).
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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Fig. 1. Flow diagram of patients. Each box shows the number of patients in each group. Gray boxes indicate patients included in the analysis. Abbreviations: LDH, primary lumber disc herniation; FELD, full endoscopic lumbar discectomy.
3. Results Patients’ characteristics are described in Table 1. Male patients comprised more than half of both groups. The surgical level was L4-5 in more than half of the patients in both groups. The selection of the surgical approach was not statistically significantly different between groups (p = 0.76). For primary LDH, TF was performed in 85 of 122 patients (70%) at L4-5, and IL was performed in 84 of 89 patients (94%) at L5-S1. For recurrent LDH, TF was performed in 14 of 18 patients (78%) at L4-5, and IL was performed in 14 of 15 patients (93%) at L5-S1. Highly migrated LDHs at L4-5 were removed with IL in 16 of 18 (89%) patients in group A and in 1 of 1 patient (100%) in group B. There was no statistically significant difference in any of the considered factors between groups (p > 0.05), but a trend for higher age and severe disc degeneration was observed in group B (Table 1). None of the clinical outcomes during the postoperative time period at 3, 6, 12, and 24 months were significantly different between the groups, adjusting for baseline values and the confounders (p > 0.05). The clinical outcomes
significantly improved from the preoperative baseline to postoperative 3 months (adjusted p < 0.01 for K-ODI, VAS-B, and VAS-L) and the improvements were maintained for 24 months postoperatively. The estimated mean differences between the two groups (group B – group A) at 24 months postoperatively were 0.69 (95% confidence interval [CI], 2.41 to 1.03; p = 0.43) for K-ODI, 0.01 (95% CI, 0.57 to 0.56; p = 0.99) for VAS-B and 0.26 (95% CI, 0.85 to 0.32; p = 0.38) for VAS-L (Table 2 and Fig. 2). Complications occurred in 14 patients (6.6%) in group A and 4 patients (9.8%) in group B (p = 0.48). Several patients had more than 2 complications. Complications included reoperation in 7 patients (within 3 months in 5 patients; 24 months in 1 and 39 months in 1 patient), transient weakness in 2 patients, dysesthesia in 2 patients, dural tear in 3 patients (TF, 1; IL, 2) and persistent leg pain in 1 patient in group A. In group B, complications included reoperation in 1 patient at 12 months, transient weakness in 1, dysesthesia in 1, and persistent leg pain in 1. Persistent leg pain was controlled with an epidural injection 1 week after surgery in both groups.
Table 1 Characteristics of patients.
Age Sex (female) Duration of symptoms BMI (kg/m2) Smoking (yes) Surgical level (L4-5) Side (right) Disc type (extrusion/sequestration) High canal compromise (yes) High grade migration (yes) Disc degeneration (severe) Modic change (yes) Surgical approach (TF)
Primary LDH (n = 211)
Recurrent LDH (n = 33)
p-value
Standardized difference
40.6 ± 10.5 105 (49.8%) 4.5 ± 4.9 24.1 ± 3.4 52 (24.6%) 122 (57.8%) 99 (46.9%) 132 (62.6%) 88 (41.7%) 29 (13.7%) 113 (53.6%) 55 (26.1%) 90 (42.7%)
44.2 ± 9.5 13 (39.4%) 5.2 ± 7.0 24.5 ± 3.3 8 (24.2%) 18 (54.5%) 12 (36.4%) 24 (72.7%) 12 (36.4%) 4 (12.1%) 23 (69.7%) 11 (33.3%) 15 (45.5%)
0.06 0.27 0.59 0.5 0.96 0.72 0.26 0.26 0.56 >0.99 0.08 0.38 0.76
0.36 0.21 0.12 0.13 0.01 0.07 0.21 0.22 0.11 0.05 0.34 0.16 0.06
Abbreviations: LDH, lumbar disc herniation; BMI, body mass index; TF, transforaminal approach.
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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Table 2 Clinical outcomes.
K-ODI VAS-B VAS-L
Primary LDH Recurrent LDH Primary LDH Recurrent LDH Primary LDH Recurrent LDH
Pre
3mo
6mo
12mo
24mo
22.5 ± 7.9 22.7 ± 9.1 6.6 ± 2.0 6.1 ± 2.4 7.0 ± 1.7 7.5 ± 1.6
10 ± 7.3 9.8 ± 6.5 2.6 ± 2.1 2.7 ± 2.3 2.4 ± 2.2 2.7 ± 2.5
8.6 ± 6.4 10.9 ± 6.3 2.8 ± 2.2 3.7 ± 1.9 2.2 ± 2.3 2.4 ± 1.9
8.8 9.5 3.0 2.7 2.4 2.0
6.6 7.1 2.7 2.1 2.1 1.6
± ± ± ± ± ±
6.9 6.8 2.2 2.2 2.4 1.8
± ± ± ± ± ±
5.9 8.2 2.4 2.4 2.3 2.4
All values are mean ± standard deviations. Abbreviations: LDH, lumbar disc herniation; K-ODI, Korean version of the Oswestry Disability Index; VAS-B, visual analogue pain score for the back; VAS-L, visual analogue pain score for the leg.
Fig. 2. Clinical outcomes. The left axis shows values of visual analogue pain scores for the back (VAS-B, x/10) and leg (VAS-L, x/10), while the right axis shows values of the Korean version of the Oswestry Disability Index (K-ODI, x/45). All parameters showed a significant decrease at postoperative 3 months, which remained stable during the 24month follow-up period.
4. Discussion The objective of the present study was to investigate longitudinal clinical outcomes after FELD for recurrent LDH in comparison with those after FELD for primary LDH. The results showed a significant clinical improvement within 3 months after surgery, and the improvement was maintained throughout the 24-month follow-up period. The outcomes were not significantly different from those obtained after FELD for primary LDH. However, the higher complication rate of FELD for recurrent LDH should be noted by both physicians and patients who are considering this procedure. 4.1. Recurrent LDH and surgical options Reoperation is performed in more than 10% of patients after surgery for primary LDH [1,2,38–41]. Because of the potential for a large annular defect after the second operation and further disc degeneration, concerns about re-recurrent herniation and poor clinical outcomes are major issues both for patients and physicians after reoperation [4,7,29]. Consequently, fusion surgery might be a logical option for treating recurrent disease. Osterman et al. showed that fusion surgery had a protective effect for further spinal surgery through a population-based study (relative risk, 0.27; 95% CI, 0.12–0.61) [1]. Systematic reviews also showed that fusion surgery reduced re-recurrence [11,12]. Although the rereoperation rate could be reduced with fusion surgery, other factors such as hospital stay, complication rate, hospital costs, and
the physical/mental burden for patients must also be considered in deciding upon a surgical method [9,10,15,17]. A systematic review could not find enough evidence to support any significant difference in outcomes between discectomy alone and discectomy with fusion [12]. When the issue of re-reoperation was set aside, clinical outcomes regarding function and pain were not significantly different between fusion surgery and non-fusion surgery [9,10,16,17]. Perhaps as a consequence, population-based studies have shown that non-fusion surgery is selected in 60–70% of patients with recurrent LDH [1,39]. Prior studies have evaluated cross-sectional clinical outcomes after non-fusion surgery for recurrent LDH. Overall, satisfactory clinical outcomes (excellent or good outcomes) were obtained in more than 80% of patients after reoperation [12]. Cinotti et al. performed a prospective study to compare clinical outcomes between patients who underwent open discectomy for recurrent LDH and primary LDH, and satisfactory clinical outcomes were obtained in 85% and 88% (p > 0.05) of patients, respectively [6]. Ahn et al. reported similar pain outcomes at 6 months postoperatively for minimally invasive lumbar discectomy between patients with recurrent LDH and primary LDH [15]. More recently, FELD was suggested as an alternative option to open discectomy for recurrent LDH [3,4,7]. Kapetanakis et al. reported longitudinal outcomes after FELD for recurrent LDH [3]. They showed that significant clinical improvement was achieved starting at 6 weeks postoperatively and that the improvement was stable for a 12-month follow-up period [3]. Hoogland et al. showed that excellent or good outcomes
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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were achieved in 86% of patients after FELD for recurrent LDH during 2 years of follow-up [4]. A randomized controlled trial conducted by Ruetten et al. showed that a favorable clinical outcome was achieved in 95% of patients after either FELD or open discectomy for recurrent LDH [7]. The re-recurrence rate was not significantly different between them (7% after FELD and 5% after open discectomy p > 0.05).[7] Similar clinical outcomes between FELD and open discectomy have also been supported by other clinical studies [7,14,42]. Revision open discectomy is expected to be technically challenging due to the presence of adhesions and thick scar tissue, but these issues can potentially be avoided by approaching the recurrent LDH through an untouched surgical trajectory with an endoscope [4,7,14,19,22,26,42]. Ruetten at al. showed that the complication rate was lower after FELD than after open discectomy; dural injury occurred after FELD in 2% of patients and after open discectomy in 6% of patients, while transient dysesthesia occurred in 4% of patients after FELD and 11% of patients after open discectomy, and surgical wound problems occurred only after open discectomy, in 7% of patients [7]. Ahn et al. showed that short operative time, short hospital stay, and disc height preservation were additional advantages of FELD for recurrent LDH [14]. Overall satisfactory clinical outcomes were achieved in more than 85% of patients after FELD for recurrent LDH, and the present study showed that the improved outcomes were stable during 24 months postoperatively [3,5,7,23,42]. In addition, the outcomes were not remarkably poor when compared with the outcomes after FELD for primary LDH. However, more complications occurred in patients with recurrent LDH than in those with primary LDH. Although this tendency was not statistically significant, the higher complication rate should not be disregarded. Moreover, FELD costs more than open discectomy in some countries and a cost-effectiveness analysis may provide further insight on the optimal option. 4.2. Limitations First, this study was underpowered due to its retrospective study design and small number of patients. However, the 95% CI for mean differences (-2.41 to 1.03 for K-ODI, 0.57 to 0.56 for VAS-B and 0.85 to 0.32 for VAS-L) seem to be negligible, considering the mean clinically important differences of those factors [43]. A large multicenter study would provide a more robust answer. Second, the surgeon’s expertise and philosophy, as well as patient characteristics, are major determinants in surgical decision-making [44]. FELD is an alternative surgical option. In this regard, this study has limitations in generalizability. The message of this study was not to recommend FELD in all patients with recurrent LDH, but to provide information for both patients and physicians who are considering FELD. 5. Conclusion FELD for recurrent LDH improved clinical outcomes within 3 months after surgery and the improvement was stable during a 24-month follow-up period. The outcomes were not significantly different from those obtained after FELD for primary LDH. However, the higher complication rate among patients undergoing FELD for recurrent LDH should be noted by both physicians and patients who are considering this procedure. Author contributions Y Choi and CH Kim had full access to all study data and take responsibility for its integrity and the accuracy of the analyses.
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Y Choi, SH Yang, CH Kim and CK Chung designed the study protocol. SB Park, CH Lee and KT Kim managed the literature searches and summaries of the previous research. Y Choi, CC Kuo and CK Kim wrote the first draft of the manuscript. CC Kuo, CH Kim, Y Choi and JM Rhee revised the intellectual content and provided the final approval of the manuscript. Declaration of Competing Interest A grant from the Korea Health Technology R&D Project supported this work through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare, Republic of Korea (HC15C1320). Grant No. 0320160210 (20161062) from the Seoul National University Hospital supported this study. This research was partially supported by Korean Spinal Neurosurgery Society. The first author (CHK) is a consultant of RIWOspine GmbH. The other authors declare that they have no conflicts of interest concerning the materials/methods used in this study or the findings described in this paper. The institutional review board at the Seoul National University Hospital approved this study (H-1611-015-803). Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jocn.2019.12.047. References [1] Osterman H, Sund R, Seitsalo S. Keskimaki I. Risk of multiple reoperations after lumbar discectomy: a population-based study. Spine (Phila Pa 1976) 2003 (28):621–7. https://www.ncbi.nlm.nih.gov/pubmed/12642772. [2] Malter AD, McNeney B, Loeser JD, Deyo RA. 5-year reoperation rates after different types of lumbar spine surgery. Spine (Phila Pa 1976) 1998 (23):814–20. http://www.ncbi.nlm.nih.gov/pubmed/9563113. [3] Kapetanakis S, Gkantsinikoudis N, Charitoudis G. The role of full-endoscopic lumbar discectomy in surgical treatment of recurrent lumbar disc herniation: a health-related quality of life approach. Neurospine 2019;16:96–104. https:// www.ncbi.nlm.nih.gov/pubmed/30943711. [4] Hoogland T, van den Brekel-Dijkstra K, Schubert M, Miklitz B. Endoscopic transforaminal discectomy for recurrent lumbar disc herniation: a prospective, cohort evaluation of 262 consecutive cases. Spine (Phila Pa 1976) 2003 (33):973–8. https://www.ncbi.nlm.nih.gov/pubmed/18427318. [5] Ahn Y, Lee SH, Park WM, Lee HY, Shin SW, Kang HY. Percutaneous endoscopic lumbar discectomy for recurrent disc herniation: surgical technique, outcome, and prognostic factors of 43 consecutive cases. Spine (Phila Pa 1976) 2003(29): E326–32. https://www.ncbi.nlm.nih.gov/pubmed/15303041. [6] Cinotti G, Roysam GS, Eisenstein SM, Postacchini F. Ipsilateral recurrent lumbar disc herniation. A prospective, controlled study. J Bone Joint Surg Br 1998;80:825–32. [7] Ruetten S, Komp M, Merk H, Godolias G. Recurrent lumbar disc herniation after conventional discectomy: a prospective, randomized study comparing fullendoscopic interlaminar and transforaminal versus microsurgical revision. J Spinal Disord Tech 2009;22:122–9. https://www.ncbi.nlm.nih.gov/pubmed/ 19342934. [8] Suk KS, Lee HM, Moon SH, Kim NH. Recurrent lumbar disc herniation: results of operative management. Spine (Phila Pa 1976) 2001(26):672–6. https:// www.ncbi.nlm.nih.gov/pubmed/11246384. [9] Yao Y, Zhang H, Wu J, Liu H, Zhang Z, Tang Y, et al. Comparison of three minimally invasive spine surgery methods for revision surgery for recurrent herniation after percutaneous endoscopic lumbar discectomy. World Neurosurg 2017;100(641–7):e1. [10] Liu C, Zhou Y. Percutaneous endoscopic lumbar diskectomy and minimally invasive transforaminal lumbar interbody fusion for recurrent lumbar disk herniation. World Neurosurg 2017;98:14–20. https://www.ncbi.nlm.nih.gov/ pubmed/27773858. [11] Ajiboye RM, Drysch A, Mosich GM, Sharma A, Pourtaheri S. Surgical treatment of recurrent lumbar disk herniation: a systematic review and metaanalysis. Orthopedics 2018;41:e457–69. https://www.ncbi.nlm.nih.gov/pubmed/ 29940051. [12] Drazin D, Ugiliweneza B, Al-Khouja L, Yang D, Johnson P, Kim T, et al. Treatment of recurrent disc herniation: a systematic review. Cureus 2016;8: e622. https://www.ncbi.nlm.nih.gov/pubmed/27382530. [13] Li X, Hu Z, Cui J, Han Y, Pan J, Yang M, et al. Percutaneous endoscopic lumbar discectomy for recurrent lumbar disc herniation. Int J Surg 2016;27:8–16. https://www.ncbi.nlm.nih.gov/pubmed/26805569.
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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Clinical study
Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy Yunhee Choi a, Chi Heon Kim b,c,d,e,⇑, John M. Rhee e, Calvin C. Kuo f, Urim Lee g, Sung Bae Park b,c,d,h, Chang-Hyun Lee b,c,d, Seung Heon Yang b,c,d, Kyoung-Tae Kim i,j, Chun Kee Chung b,c,d,g,k a
Medical Research Collaborating Center, Seoul National University Hospital, 101 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea Department of Neurosurgery, Seoul National University College of Medicine, 103 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea Department of Neurosurgery, Seoul National University Hospital, 101 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea d Clinical Research Institute, Seoul National University Hospital, 101 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea e Department of Orthopaedic Surgery and Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA f Regional Spine Surgery Department, Kaiser Permanente, 3600 Broadway, Suite 15, Oakland, CA 94611, USA g Human Brain Function Laboratory, Department of Neurosurgery, Seoul National University Hospital, 101 Daehak-Ro, Jongno-gu, Seoul 03080, South Korea h Department of Neurosurgery, Seoul National University Boramae Hospital, Borame Medical Center 20, Boramae-ro 5-gil, Dongjak-gu, Seoul 07061, South Korea i Department of Neurosurgery, Kyungpook National University Hospital, 130 Dongdeok-ro, Jung-gu, Daegu 41944, South Korea j Department of Neurosurgery, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 41944, South Korea k Department of Brain and Cognitive Sciences, Seoul National University College of Natural Sciences, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea b c
a r t i c l e
i n f o
Article history: Received 14 September 2019 Accepted 20 December 2019 Available online xxxx Keywords: Lumbar vertebrae Pain Endoscopic discectomy Recurrence Spine Surgery Treatment outcome
a b s t r a c t Objective: Full-endoscopic lumbar discectomy (FELD) is a minimally invasive surgical option for recurrent lumbar disc herniation (LDH). Nonetheless, patients’ clinical outcomes may be poorer after surgery for recurrent LDH than for primary LDH. Therefore, we compared patients’ longitudinal clinical outcomes after FELD for recurrent LDH or primary LDH. Methods: The medical records of patients who underwent FELD for primary LDH (group A) or recurrent LDH (group B) were retrospectively reviewed. The inclusion criteria were: 1) single-level LDH or recurrent LDH at L4-5 or L5-S1, 2) age 60 years, 3) previous open discectomy (group B), and 4) 6 months of follow-up. In total, 244 patients (group A, 211; group B, 33) were included. Clinical outcomes (Oswestry Disability Index [ODI]; visual analogue pain score for the back and leg [VAS-B] and [VAS-L]) over 24 months of follow-up were compared between groups with a linear mixed-effects model. Results: All clinical outcomes significantly improved from pre-operation to 3 months postoperatively (p < 0.01), and the improvement was maintained for 24 months postoperatively in both groups. The clinical outcomes of groups A and B were not significantly different during 24 months follow-up (ODI, p = 0.94; VAS-B, p = 0.11; and VAS-L, p = 0.48). The reoperation rate was 3.3% in group A and 3.0% in group B, but the overall complication rate was higher in group B (9.8%) than in group A (6.6%). Conclusion: The longitudinal clinical outcomes after FELD for recurrent LDH may not be poor as feared. However, the higher complication rate in patients undergoing FELD for recurrent LDH should be noted. Ó 2019 Elsevier Ltd. All rights reserved.
1. Introduction Recurrent lumbar disc herniation (LDH), which is a major concern after surgery for primary LDH, occurs in approximately 10% of patients [1–3]. Non-surgical modalities such as medications, physiotherapy, or interventional injections are first-line treatments for recurrent LDH, but surgical treatment is considered if
⇑ Corresponding author: Department of Neurosurgery, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-gu, Seoul 110-744, South Korea. E-mail address: [email protected] (C.H. Kim).
those treatments are not effective for 6 weeks, pain is incapacitating, or substantial motor weakness is present [1]. However, revision discectomy is more complex than primary surgery because of scar formation, progressed disc degeneration, and the higher likelihood of less satisfactory clinical outcomes and re-recurrence [4–8]. Some authors advocate fusion surgery due to those issues, but fusion surgery has been associated with a longer surgical time, longer hospital stay, higher hospital costs, and higher rates of surgery-related complications than nonfusion discectomy [1,9–13]. A systematic review showed that clinical outcomes such as functional disability, low back pain, and leg
https://doi.org/10.1016/j.jocn.2019.12.047 0967-5868/Ó 2019 Elsevier Ltd. All rights reserved.
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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pain were not significantly different between patients who underwent discectomy with fusion and those who underwent discectomy without fusion, and excellent or good surgical outcomes were achieved in more than 80% of patients without fusion surgery [8,11–14]. For those reasons, non-fusion surgery was chosen for 77% of patients in a population-based study, and revision discectomy remains a viable surgical option [1,6,12,15–18]. More recently, full-endoscopic lumbar discectomy (FELD) has been utilized for recurrent LDH, with comparable results to open discectomy [5,9,19–23]. The advantages of FELD for recurrent LDH include a short hospital stay, minimal tissue injury, and less need to go through scar tissue; therefore, FELD may be an alternative surgical technique [3,13,21]. Nonetheless, there are concerns that most patients may experience poorer longitudinal clinical outcomes with time and that outcomes may be poorer after surgery for recurrent LDH than for primary LDH. In this context, we investigated patients’ longitudinal clinical outcomes after FELD for recurrent LDH in comparison with those after FELD for primary LDH.
ments were removed using forceps. In group A, fragmentectomy of the herniated disc and removal of loose disc fragments under the herniated disc were generally sufficient because they had small annular defects [7,21,24,25,29]. However, more extensive removal of loose disc fragments was sometimes necessary in group B, because more disc material may remain in the setting of an large annular defect [7,15,29]. For IL, an 8-mm skin incision was made at the skin above the interlaminar space, and the dilator and working tube were sequentially introduced. The ligamentum flavum was opened for primary LDH, and the ruptured disc and all graspable loose disc fragments were removed using forceps or flexible forceps. For recurrent LDH, the scar tissue was dissected from the medial facet joint with a working tube, and the scar tissue and the neural tissue were retracted together with the working tube [19,26]. The ruptured disc and all graspable loose disc fragments were removed using forceps. A larger amount of loose disc fragments was removed for recurrent LDH than for primary LDH. The working tube and endoscope were pulled out after confirmation of decompression and hemostasis, and the skin was closed using 3–0 Nylon sutures.
2. Materials and methods 2.1. Materials
2.3. Postoperative management
Since 2005, all clinical and radiological data for patients undergoing FELD were prospectively recorded using an electronic medical records system (IRB No. 0507-509-153) [24,25]. Informed consent was obtained from all patients. After approval from our institutional review board (IRB No. 1611-015-803), the prospectively collected medical records were retrospectively reviewed for patients who underwent FELD from 2009 to 2016. FELD was indicated when symptomatic primary LDH or recurrent LDH was incapacitating for more than 6 weeks with non-surgical treatment, or neurological weakness (manual motor power of less than 3 out of 5) was present [24,25]. We selected patients according to the following inclusion criteria: 1) single-level LDH or recurrent LDH at L4-5 or L5-S1, 2) age 60 years, 3) symptomatic primary LDH or recurrent LDH verified with magnetic resonance imaging, 4) previous history of open discectomy for patients with recurrent LDH, 5) absence of spinal stenosis at any level, 6) absence of a psychiatric or neuromuscular diagnosis, such as depression or Parkinson disease, and 7) a follow-up period longer than 6 months [24,25]. A total of 244 patients (group A, FELD for primary LDH, 211; group B, FELD for recurrent LDH, 33) were included in the present study (Fig. 1).
The preoperative and postoperative management protocols were the same in all patients. Patients were encouraged to ambulate on the day of surgery and all patients were discharged the next day if their symptoms had improved [24–26]. Patients were scheduled to visit the clinic at 3, 6, and 12 months postoperatively and yearly thereafter. Additionally, patients were encouraged to visit an outpatient clinic at any time when they experienced intractable pain. Patients were asked to fill out patient-reported-outcome questionnaires, including the Korean version of the Oswestry Disability Index (K-ODI, x/45) and visual analogue pain scores for the back (VAS-B, x/10) and leg (VAS-L, x/10) on each clinic visit day [30,31]. The median follow-up period was 24.2 months (range, 6–81) for group A and 24.4 months (range, 6–62) for group B.
2.2. Surgical techniques Standard surgical techniques were used in both groups [7,19– 22,24–27]. The selection of the surgical approach was the same for both groups; primarily, a transforaminal approach (TF) was used for L4-5 and an interlaminar approach (IL) for L5-S1 [24– 26]. IL was preferred for patients with high-grade superior or inferior migrated LDH at any level, an LDH exhibiting high-grade (>50%) canal compromise, or a high iliac crest [20,24–26,28]. All operations were done with the patient in the prone position under general anesthesia, fluoroscopic guidance, and electromyographic monitoring. The basic surgical techniques of TF and IL were as follows. For TF, an 18-gauge needle was inserted from the symptomatic side aiming at the neural foramen of the disc herniation under fluoroscopic guidance. A guidewire was inserted, and an 8mm skin incision was made. The dilator and the working tube were sequentially introduced. An endoscope (Vertebris system; RIWOspine GmbH, Knittlingen, Germany) was introduced after the dilator was removed. The ruptured disc and all graspable loose disc frag-
2.4. Statistical analysis Continuous and non-continuous values were compared using the t-test and chi-square test (or the Fisher exact test), respectively, and using the standardized difference. Since the sample size was small, the confounders for comparisons of clinical outcomes (K-ODI, VAS-B and VAS-L) were determined considering p-values <0.1 and a standardized difference >0.2. Clinical outcomes were longitudinally compared between group A and group B for 24 months with a linear mixed-effects model. The random effect was the subjects. The fixed effects included group, time, the interaction between group and time, the baseline values of clinical outcomes, and confounders. The factors considered as confounders were age, sex, duration of recent symptoms, body mass index (kg/m2), smoking status (yes vs. no), surgical level, side of symptom, disc type (bulging/protrusion vs. extrusion/sequestration) [32], high-grade canal compromise by the LDH (>50% of the spinal canal) [20,33], high-grade migration [20,34], disc degeneration (Pfirrmann grade at the index level [grade 1–3 vs. 4–5]) [35,36], the presence of Modic changes (yes vs. no), and the surgical approach (TF vs IL) [37]. A post hoc analysis was planned using the stepdown Bonferroni method to test the changes between the preoperative and postoperative (3, 6, 12, and 24 months) time points. All statistical analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC, USA). Statistical significance was defined as p < 0.05 (2-sided).
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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Fig. 1. Flow diagram of patients. Each box shows the number of patients in each group. Gray boxes indicate patients included in the analysis. Abbreviations: LDH, primary lumber disc herniation; FELD, full endoscopic lumbar discectomy.
3. Results Patients’ characteristics are described in Table 1. Male patients comprised more than half of both groups. The surgical level was L4-5 in more than half of the patients in both groups. The selection of the surgical approach was not statistically significantly different between groups (p = 0.76). For primary LDH, TF was performed in 85 of 122 patients (70%) at L4-5, and IL was performed in 84 of 89 patients (94%) at L5-S1. For recurrent LDH, TF was performed in 14 of 18 patients (78%) at L4-5, and IL was performed in 14 of 15 patients (93%) at L5-S1. Highly migrated LDHs at L4-5 were removed with IL in 16 of 18 (89%) patients in group A and in 1 of 1 patient (100%) in group B. There was no statistically significant difference in any of the considered factors between groups (p > 0.05), but a trend for higher age and severe disc degeneration was observed in group B (Table 1). None of the clinical outcomes during the postoperative time period at 3, 6, 12, and 24 months were significantly different between the groups, adjusting for baseline values and the confounders (p > 0.05). The clinical outcomes
significantly improved from the preoperative baseline to postoperative 3 months (adjusted p < 0.01 for K-ODI, VAS-B, and VAS-L) and the improvements were maintained for 24 months postoperatively. The estimated mean differences between the two groups (group B – group A) at 24 months postoperatively were 0.69 (95% confidence interval [CI], 2.41 to 1.03; p = 0.43) for K-ODI, 0.01 (95% CI, 0.57 to 0.56; p = 0.99) for VAS-B and 0.26 (95% CI, 0.85 to 0.32; p = 0.38) for VAS-L (Table 2 and Fig. 2). Complications occurred in 14 patients (6.6%) in group A and 4 patients (9.8%) in group B (p = 0.48). Several patients had more than 2 complications. Complications included reoperation in 7 patients (within 3 months in 5 patients; 24 months in 1 and 39 months in 1 patient), transient weakness in 2 patients, dysesthesia in 2 patients, dural tear in 3 patients (TF, 1; IL, 2) and persistent leg pain in 1 patient in group A. In group B, complications included reoperation in 1 patient at 12 months, transient weakness in 1, dysesthesia in 1, and persistent leg pain in 1. Persistent leg pain was controlled with an epidural injection 1 week after surgery in both groups.
Table 1 Characteristics of patients.
Age Sex (female) Duration of symptoms BMI (kg/m2) Smoking (yes) Surgical level (L4-5) Side (right) Disc type (extrusion/sequestration) High canal compromise (yes) High grade migration (yes) Disc degeneration (severe) Modic change (yes) Surgical approach (TF)
Primary LDH (n = 211)
Recurrent LDH (n = 33)
p-value
Standardized difference
40.6 ± 10.5 105 (49.8%) 4.5 ± 4.9 24.1 ± 3.4 52 (24.6%) 122 (57.8%) 99 (46.9%) 132 (62.6%) 88 (41.7%) 29 (13.7%) 113 (53.6%) 55 (26.1%) 90 (42.7%)
44.2 ± 9.5 13 (39.4%) 5.2 ± 7.0 24.5 ± 3.3 8 (24.2%) 18 (54.5%) 12 (36.4%) 24 (72.7%) 12 (36.4%) 4 (12.1%) 23 (69.7%) 11 (33.3%) 15 (45.5%)
0.06 0.27 0.59 0.5 0.96 0.72 0.26 0.26 0.56 >0.99 0.08 0.38 0.76
0.36 0.21 0.12 0.13 0.01 0.07 0.21 0.22 0.11 0.05 0.34 0.16 0.06
Abbreviations: LDH, lumbar disc herniation; BMI, body mass index; TF, transforaminal approach.
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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Table 2 Clinical outcomes.
K-ODI VAS-B VAS-L
Primary LDH Recurrent LDH Primary LDH Recurrent LDH Primary LDH Recurrent LDH
Pre
3mo
6mo
12mo
24mo
22.5 ± 7.9 22.7 ± 9.1 6.6 ± 2.0 6.1 ± 2.4 7.0 ± 1.7 7.5 ± 1.6
10 ± 7.3 9.8 ± 6.5 2.6 ± 2.1 2.7 ± 2.3 2.4 ± 2.2 2.7 ± 2.5
8.6 ± 6.4 10.9 ± 6.3 2.8 ± 2.2 3.7 ± 1.9 2.2 ± 2.3 2.4 ± 1.9
8.8 9.5 3.0 2.7 2.4 2.0
6.6 7.1 2.7 2.1 2.1 1.6
± ± ± ± ± ±
6.9 6.8 2.2 2.2 2.4 1.8
± ± ± ± ± ±
5.9 8.2 2.4 2.4 2.3 2.4
All values are mean ± standard deviations. Abbreviations: LDH, lumbar disc herniation; K-ODI, Korean version of the Oswestry Disability Index; VAS-B, visual analogue pain score for the back; VAS-L, visual analogue pain score for the leg.
Fig. 2. Clinical outcomes. The left axis shows values of visual analogue pain scores for the back (VAS-B, x/10) and leg (VAS-L, x/10), while the right axis shows values of the Korean version of the Oswestry Disability Index (K-ODI, x/45). All parameters showed a significant decrease at postoperative 3 months, which remained stable during the 24month follow-up period.
4. Discussion The objective of the present study was to investigate longitudinal clinical outcomes after FELD for recurrent LDH in comparison with those after FELD for primary LDH. The results showed a significant clinical improvement within 3 months after surgery, and the improvement was maintained throughout the 24-month follow-up period. The outcomes were not significantly different from those obtained after FELD for primary LDH. However, the higher complication rate of FELD for recurrent LDH should be noted by both physicians and patients who are considering this procedure. 4.1. Recurrent LDH and surgical options Reoperation is performed in more than 10% of patients after surgery for primary LDH [1,2,38–41]. Because of the potential for a large annular defect after the second operation and further disc degeneration, concerns about re-recurrent herniation and poor clinical outcomes are major issues both for patients and physicians after reoperation [4,7,29]. Consequently, fusion surgery might be a logical option for treating recurrent disease. Osterman et al. showed that fusion surgery had a protective effect for further spinal surgery through a population-based study (relative risk, 0.27; 95% CI, 0.12–0.61) [1]. Systematic reviews also showed that fusion surgery reduced re-recurrence [11,12]. Although the rereoperation rate could be reduced with fusion surgery, other factors such as hospital stay, complication rate, hospital costs, and
the physical/mental burden for patients must also be considered in deciding upon a surgical method [9,10,15,17]. A systematic review could not find enough evidence to support any significant difference in outcomes between discectomy alone and discectomy with fusion [12]. When the issue of re-reoperation was set aside, clinical outcomes regarding function and pain were not significantly different between fusion surgery and non-fusion surgery [9,10,16,17]. Perhaps as a consequence, population-based studies have shown that non-fusion surgery is selected in 60–70% of patients with recurrent LDH [1,39]. Prior studies have evaluated cross-sectional clinical outcomes after non-fusion surgery for recurrent LDH. Overall, satisfactory clinical outcomes (excellent or good outcomes) were obtained in more than 80% of patients after reoperation [12]. Cinotti et al. performed a prospective study to compare clinical outcomes between patients who underwent open discectomy for recurrent LDH and primary LDH, and satisfactory clinical outcomes were obtained in 85% and 88% (p > 0.05) of patients, respectively [6]. Ahn et al. reported similar pain outcomes at 6 months postoperatively for minimally invasive lumbar discectomy between patients with recurrent LDH and primary LDH [15]. More recently, FELD was suggested as an alternative option to open discectomy for recurrent LDH [3,4,7]. Kapetanakis et al. reported longitudinal outcomes after FELD for recurrent LDH [3]. They showed that significant clinical improvement was achieved starting at 6 weeks postoperatively and that the improvement was stable for a 12-month follow-up period [3]. Hoogland et al. showed that excellent or good outcomes
Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047
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were achieved in 86% of patients after FELD for recurrent LDH during 2 years of follow-up [4]. A randomized controlled trial conducted by Ruetten et al. showed that a favorable clinical outcome was achieved in 95% of patients after either FELD or open discectomy for recurrent LDH [7]. The re-recurrence rate was not significantly different between them (7% after FELD and 5% after open discectomy p > 0.05).[7] Similar clinical outcomes between FELD and open discectomy have also been supported by other clinical studies [7,14,42]. Revision open discectomy is expected to be technically challenging due to the presence of adhesions and thick scar tissue, but these issues can potentially be avoided by approaching the recurrent LDH through an untouched surgical trajectory with an endoscope [4,7,14,19,22,26,42]. Ruetten at al. showed that the complication rate was lower after FELD than after open discectomy; dural injury occurred after FELD in 2% of patients and after open discectomy in 6% of patients, while transient dysesthesia occurred in 4% of patients after FELD and 11% of patients after open discectomy, and surgical wound problems occurred only after open discectomy, in 7% of patients [7]. Ahn et al. showed that short operative time, short hospital stay, and disc height preservation were additional advantages of FELD for recurrent LDH [14]. Overall satisfactory clinical outcomes were achieved in more than 85% of patients after FELD for recurrent LDH, and the present study showed that the improved outcomes were stable during 24 months postoperatively [3,5,7,23,42]. In addition, the outcomes were not remarkably poor when compared with the outcomes after FELD for primary LDH. However, more complications occurred in patients with recurrent LDH than in those with primary LDH. Although this tendency was not statistically significant, the higher complication rate should not be disregarded. Moreover, FELD costs more than open discectomy in some countries and a cost-effectiveness analysis may provide further insight on the optimal option. 4.2. Limitations First, this study was underpowered due to its retrospective study design and small number of patients. However, the 95% CI for mean differences (-2.41 to 1.03 for K-ODI, 0.57 to 0.56 for VAS-B and 0.85 to 0.32 for VAS-L) seem to be negligible, considering the mean clinically important differences of those factors [43]. A large multicenter study would provide a more robust answer. Second, the surgeon’s expertise and philosophy, as well as patient characteristics, are major determinants in surgical decision-making [44]. FELD is an alternative surgical option. In this regard, this study has limitations in generalizability. The message of this study was not to recommend FELD in all patients with recurrent LDH, but to provide information for both patients and physicians who are considering FELD. 5. Conclusion FELD for recurrent LDH improved clinical outcomes within 3 months after surgery and the improvement was stable during a 24-month follow-up period. The outcomes were not significantly different from those obtained after FELD for primary LDH. However, the higher complication rate among patients undergoing FELD for recurrent LDH should be noted by both physicians and patients who are considering this procedure. Author contributions Y Choi and CH Kim had full access to all study data and take responsibility for its integrity and the accuracy of the analyses.
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Y Choi, SH Yang, CH Kim and CK Chung designed the study protocol. SB Park, CH Lee and KT Kim managed the literature searches and summaries of the previous research. Y Choi, CC Kuo and CK Kim wrote the first draft of the manuscript. CC Kuo, CH Kim, Y Choi and JM Rhee revised the intellectual content and provided the final approval of the manuscript. Declaration of Competing Interest A grant from the Korea Health Technology R&D Project supported this work through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare, Republic of Korea (HC15C1320). Grant No. 0320160210 (20161062) from the Seoul National University Hospital supported this study. This research was partially supported by Korean Spinal Neurosurgery Society. The first author (CHK) is a consultant of RIWOspine GmbH. The other authors declare that they have no conflicts of interest concerning the materials/methods used in this study or the findings described in this paper. The institutional review board at the Seoul National University Hospital approved this study (H-1611-015-803). Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jocn.2019.12.047. References [1] Osterman H, Sund R, Seitsalo S. Keskimaki I. Risk of multiple reoperations after lumbar discectomy: a population-based study. Spine (Phila Pa 1976) 2003 (28):621–7. https://www.ncbi.nlm.nih.gov/pubmed/12642772. [2] Malter AD, McNeney B, Loeser JD, Deyo RA. 5-year reoperation rates after different types of lumbar spine surgery. Spine (Phila Pa 1976) 1998 (23):814–20. http://www.ncbi.nlm.nih.gov/pubmed/9563113. [3] Kapetanakis S, Gkantsinikoudis N, Charitoudis G. The role of full-endoscopic lumbar discectomy in surgical treatment of recurrent lumbar disc herniation: a health-related quality of life approach. Neurospine 2019;16:96–104. https:// www.ncbi.nlm.nih.gov/pubmed/30943711. [4] Hoogland T, van den Brekel-Dijkstra K, Schubert M, Miklitz B. Endoscopic transforaminal discectomy for recurrent lumbar disc herniation: a prospective, cohort evaluation of 262 consecutive cases. Spine (Phila Pa 1976) 2003 (33):973–8. https://www.ncbi.nlm.nih.gov/pubmed/18427318. [5] Ahn Y, Lee SH, Park WM, Lee HY, Shin SW, Kang HY. Percutaneous endoscopic lumbar discectomy for recurrent disc herniation: surgical technique, outcome, and prognostic factors of 43 consecutive cases. Spine (Phila Pa 1976) 2003(29): E326–32. https://www.ncbi.nlm.nih.gov/pubmed/15303041. [6] Cinotti G, Roysam GS, Eisenstein SM, Postacchini F. Ipsilateral recurrent lumbar disc herniation. A prospective, controlled study. J Bone Joint Surg Br 1998;80:825–32. [7] Ruetten S, Komp M, Merk H, Godolias G. Recurrent lumbar disc herniation after conventional discectomy: a prospective, randomized study comparing fullendoscopic interlaminar and transforaminal versus microsurgical revision. J Spinal Disord Tech 2009;22:122–9. https://www.ncbi.nlm.nih.gov/pubmed/ 19342934. [8] Suk KS, Lee HM, Moon SH, Kim NH. Recurrent lumbar disc herniation: results of operative management. Spine (Phila Pa 1976) 2001(26):672–6. https:// www.ncbi.nlm.nih.gov/pubmed/11246384. [9] Yao Y, Zhang H, Wu J, Liu H, Zhang Z, Tang Y, et al. Comparison of three minimally invasive spine surgery methods for revision surgery for recurrent herniation after percutaneous endoscopic lumbar discectomy. World Neurosurg 2017;100(641–7):e1. [10] Liu C, Zhou Y. Percutaneous endoscopic lumbar diskectomy and minimally invasive transforaminal lumbar interbody fusion for recurrent lumbar disk herniation. World Neurosurg 2017;98:14–20. https://www.ncbi.nlm.nih.gov/ pubmed/27773858. [11] Ajiboye RM, Drysch A, Mosich GM, Sharma A, Pourtaheri S. Surgical treatment of recurrent lumbar disk herniation: a systematic review and metaanalysis. Orthopedics 2018;41:e457–69. https://www.ncbi.nlm.nih.gov/pubmed/ 29940051. [12] Drazin D, Ugiliweneza B, Al-Khouja L, Yang D, Johnson P, Kim T, et al. Treatment of recurrent disc herniation: a systematic review. Cureus 2016;8: e622. https://www.ncbi.nlm.nih.gov/pubmed/27382530. [13] Li X, Hu Z, Cui J, Han Y, Pan J, Yang M, et al. Percutaneous endoscopic lumbar discectomy for recurrent lumbar disc herniation. Int J Surg 2016;27:8–16. https://www.ncbi.nlm.nih.gov/pubmed/26805569.
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Please cite this article as: Y. Choi, C. H. Kim, J. M. Rhee et al., Longitudinal clinical outcomes after full-endoscopic lumbar discectomy for recurrent disc herniation after open discectomy, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.12.047