Feasibility of recurrent herniation surgery with biportal endoscopic discectomy:A comparison of biportal endoscopic discectomy and microscopic discectomy for recurrent disc herniation

Feasibility of recurrent herniation surgery with biportal endoscopic discectomy:A comparison of biportal endoscopic discectomy and microscopic discectomy for recurrent disc herniation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Feasibility of recurrent herniation surgery with biportal endoscopic discectomy:A comparison of biportal endoscopic discectomy and microscopic discectomy for recurrent disc herniation Sang Youp Han, Sang Hyub Lee, Jae-Won Jang, Dong-Geun Lee, Yong Eun Cho, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6141959/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background : In this study, we aimed to compare the clinical outcomes of unilateral biportal endoscopic lumbar discectomy (UBE) and open lumbar microdiscectomy (MD) for recurrent disc herniation. Methods : Ninety patients who underwent discectomy, including 44 and 46 who underwent UBE and MD, respectively, were enrolled. All surgeries were performed between March 2020 and April 2023. Only patients with single-level recurrence were included; patients with multilevel recurrence or unstable disease, as well as those who had undergone surgery less than 6 months prior, were excluded. Visual Analog Scale (VAS) scores, recurrence rates, and complications were compared between the groups. Results : The average follow-up periods were 19.09 months and 20.45 months in the UBE revision and MD revision discectomy groups, respectively. The mean bleeding loss and hospital stay were significantly shorter in the UBE group than in the MD group. Postoperative short-term back pain was significantly lower in the UBE group (VAS score, 3.32) than in the MD group (VAS score, 7.89). Radiating pain showed similar patterns in both groups at all time points. The recurrence rates were 4.55% and 8.7% in the UBE and MD groups, respectively. Regarding complications, 3 (6.81%) and 4 (8.7%) patients experienced dural tears in the UBE and MD revision groups, respectively. Conclusion : Both UBE and MD could achieve good long-term outcomes; however, UBE revision was superior in terms of short-term back pain, bleeding loss, and length of hospital stay after surgery. revision surgery discectomy endoscopy disc herniation Figures Figure 1 Figure 2 1. INTRODUCTION Several studies have demonstrated the advantages of unilateral biportal endoscopic (UBE) surgery. This endoscopic discectomy reduces postoperative pain, due to small wounds, and complications such as incidental durotomy and neural injury during surgery with good surgical vision [ 1 ]. In addition, postoperative instability is prevented by preserving the lumbar posterior columns with less infection after surgery. However, few studies have investigated the benefits of biportal endoscopic revision discectomy. Several studies comparing surgery through revision percutaneous endoscopic lumbar discectomy (PELD) and microscopic revision discectomy (MD) showed the numerous benefits of PELD [ 2 , 3 ]. However, few studies have compared the clinical outcomes of UBE and MD. To address this knowledge gap, in the present study, we compared the serial pain outcomes in patients who underwent UBE and MD and compared the associated complication and recurrence rates. 2. METHODS 2.1. Patients Patients who underwent surgery at our hospital between March 2020 and April 2023 were examined for the recurrence of herniated nucleus pulposus. This cohort included 44 and 46 patients who underwent UBE and MD, respectively. Nine skilled surgeons, all were experts in both UBE and MD, performed all surgeries. Demographic characteristics, time interval since previous surgery, operative level, length of hospital stay, blood loss, and operative time were reviewed. Regarding clinical evaluation, visual analog scale (VAS) scores for the operation site and radiating pain were measured before and after surgery. Preoperative and postoperative radiological images (radiography and magnetic resonance imaging [MRI]) were routinely taken one day after surgery and compared. Data analysis was performed using SPSS ver 28.0 (SPSS Inc., Chicago, IL, USA). 2.2. Indications and inclusion/exclusion criteria Patients with single-level radiculopathy or lower back pain caused by reherniated discs were enrolled. Only patients who underwent open microscopic discectomy for a period of more than six months without symptoms were included. This study was approved by the Institutional Review Board (approval no.: 2023-W09) of the Wiltse Memorial Hospital Spine Center. Patients with multilevel symptoms, ambiguous symptoms, previous fusion surgery, calcified discs, severe neurological deficits, or instability were excluded. 2.3. Preoperative and postoperative evaluation VAS scores were calculated preoperatively; immediate postoperatively; one day postoperatively; at discharge (average: UBE = 4.57 ± 2.84 days, MD = 7.0 ± 3.91 days); and at 1 and 3 months postoperatively. The number of intravenous and intramuscular painkillers administered on the day of surgery was also compared between the two groups. Painkillers were counted as the number of intravenous bolus paracetamol (Profa infusion 75 mL, Dai Han Pharma Korea Ltd., Seoul, Korea), intramuscular pethidine 25 mg, and tramadol 50 mg injections. The recurrence rate after surgery was divided into early and late stages, with the cutoff set at 14 days after surgery. Postoperative complications were also assessed. 2.4. Operation procedures All surgeries were performed under general or epidural anesthesia. The patients were placed in the prone position. Two holes were created on the ipsilateral side using a C-arm, with location based on the pedicle line above and below the disc space, 1 cm outside the midline (usually near the medial pedicle line). Location changed slightly, depending on the case. The surgeon’s right portal was usually located as a working portal, either to the left (0.5 cm) or right as 1.0 cm, and an incision was performed. After identifying the laminar and inferior articular processes, lateral decompression was performed using a high-speed diamond drill (no-cutting drill). Care was taken, as the ligamentum flavum may have been removed during a previous surgery. Neural tissue margins were secured through sufficient drilling. If the instrument was squeezed into a narrow space, the chances of a durotomy or neural damage were high. Once the surgical anatomy was confirmed, surgery was performed by thinning the inner bone by approximately 1 mm and carefully removing it using a curette, rather than directly drilling the inner cortical bone attached to the adhesion tissue. After removing the adhesion tissue, normal neural tissue was observed. This could be peeled off from the virgin area of the cranial part without durotomy, if required. After sufficient neural tissue exposure, the ventral adhesion was peeled off, and root retraction was performed for discectomy. If the adhesion was very severe, a lateral annulotomy was performed to secure space by internal decompression and gradually release the adhesion. After removing the disc fragment, the remnant disc around the torn disc was examined. Remnant discs could be more effectively removed using the Valsalva maneuver. After sufficient neural decompression, bleeding control, JP drain insertion, and surgery were performed. 3. RESULTS 3.1 Patients Ninety patients were enrolled in this study, of whom 44 underwent UBE and 46 underwent MD. The mean age of the patients undergoing UBE was 48.9 years old (28 men and 16 women; range: 26–79), and that of the patients treated with MD was 52.2 years old (31 men and 15 women; range 30–88), showing almost the same pattern. The most common surgical level in both groups was L4/5 (UBE = 61.3%, MD = 67.3%). The mean follow-up periods were 19.09 ± 10.22 in the UBE group and 20.45 ± 7.79 in the MD group ( p ≤ .0001). All surgeries were performed from March 2020 to March 2023. Demographic data are presented in Table 1. 3.2. Clinical outcomes The mean operation time was similar in both groups (UBE = 107.61 ± 35.87 minutes, MD = 107.50 ± 23.57 minutes, p ≤ .0001). However, the hospital length of stay was significantly shorter in the UBE group than in the MD group (UBE = 4.57 ± 2.84 days, MD = 7.0 ± 3.91 days, p = 0.169). The bleeding loss was also shorter in the UBE group (UBE = 34.09 ± 20.75 ml, MD = 41.82 ± 24.13 ml, p = 0.0569), without showing significant difference. There was no significant difference in the preoperative pain between the groups. However, there was a significant difference in postoperative back pain (VAS score: UBE = 3.32 ± 0.91, MD = 7.89 ± 1.06, p = 0.561). In addition, the number of painkillers used on the day of surgery was also confirmed to be higher in the MD group than in the UBE group (MD = 1.66 ± 1.22, UBE = 1.36 ± 0.84, p ≤ .0001). This difference in back pain continued until discharge. However, there was no difference between the two groups in the long term after 1 month. Postoperative radiating pain significantly improved in both groups without significant differences (Table 2, Fig. 1 ). 3.3 Recurrence and complications Recurrence after surgery was classified as either early or late (with 14 days as the cutoff). Early recurrence occurred in one case in the UBE group and two cases in the MD group. Late recurrence occurred in one patient in the UBE group (postoperative day 6 months) and twice in one patient in the MD group (5 and 18 months postoperatively). Patients in the UBE group underwent fusion surgery, and those in the MD group underwent MD twice. The overall recurrence rates were 4.55% and 8.7% in the UBE and MD groups, respectively (Table 3). Dural tears occurred in three patients in the UBE group and four patients in the MD group. In all cases, the patients recovered after conservative treatment using primary sutures. In addition, the UBE group was treated with peroral antibiotics and re-sutured because of the occurrence of wound dehiscence in two cases. The MD group underwent aspiration and re-suture due to the occurrence of wound dehiscence in one patient, while hematoma removal was performed due to postoperative hematoma. No major complications such as wound infection or nerve tissue damage occurred in any of the patients (Table 4). 4. CONCLUSIONS Recurrent disc herniation is a common complication after lumbar discectomy, occurring in 5–18% of patients [ 4 – 8 ]. In addition, the rate of surgical treatment of recurrent disc herniation is quite high at, approximately 62% [ 9 – 11 ]. Of note, the results of revision lumbar discectomy have been reported to be favorable [ 12 , 13 ]. However, patients experience discomfort during the process. In addition, revision surgery for recurrent disc herniation is more difficult and associated with a higher rate of complications than is virgin surgery. Scar tissue usually makes repeat microscopic discectomy more difficult and increases the risk of dural tears and/or nerve root injury [ 2 , 5 , 14 – 18 ]. The incidence of dural tears during repeat microscopic discectomy has been reported in up to 20% of patients [ 19 , 20 ]. Experienced surgeons can also perform durotomy when performing adhesiolysis. Durotomy increases hospital stay, while cerebral nervous system infection can cause fetal problems. In addition, maintaining absolute bed rest or lumbar drain insertion for durotomy causes discomfort among patients. However, surgery using an endoscope can reduce patient discomfort, lower the complication rate by magnifying surgical vision, and reduce posterior column damage [ 3 ]. Lee et al. [ 21 ] previously reported that the complication rate was lower than that of MD (UBE = 4% vs. MD = 10.3%) when revision surgery was performed using PELD. In addition, two cases of durotomy occurred only in the MD revision group (UBE = 0% vs. MD = 6.9%). Kang et al. [ 22 ] reported that UBE revision surgery provided faster pain relief and earlier functional recovery than did MD revision surgery. This study also showed that the immediate postoperative outcome was better than that of MD. Moreover, the results of long-term follow-up over six weeks were similar in both groups. Additionally, the incidence of incidental durotomy was lower than that of MD (6.3% vs. 10%). This study also confirmed that the UBE group had a lower incidence of durotomy than did the MD group (UBE = 6.8% vs. MD = 8.7%). Importantly, since the number of durotomy procedures was small and there was only one case, this difference did not reach significance. However, durotomies occurred less frequently. The surgical field of view achieved during UBE is much better than that achieved using a microscope; the possibility of incidental durotomy can be reduced as it can be performed by checking for blind spots that cannot be seen under a microscope. In addition, when MD is performed, venous bleeding may occur; the surgical field of view may be obscured as there is no venous bleeding due to water pressure with UBE. This technique also has the advantage of keeping the surgical field clean (Fig. 2 ). However, if a durotomy is performed during UBE surgery, serious problems can arise. When water flows into the durotomy site, the intracranial pressure increases, causing neurological deterioration. Symptoms such as seizures or mental retardation may occur. As such, completing the operation as soon as possible if a durotomy occurs is necessary. Furthermore, the surgical method should be changed to conventional microscopic discectomy if the operation is prolonged. Neural tissue damage is another complication that may occur during revision surgery is. Since the ligamentum flavum had already been removed, the neural tissue is immediately exposed without protection. Neural tissue damage can occur when a mistake is made during the bone drilling process or when a punch is used. However, improvements in the field of view can reduce the likelihood of neural damage; as such, UBE is associated with a lower risk of neural damage because the nerves are sunken due to water pressure. In addition, this water pressure facilitates adhesiolysis, and thermal damage is reduced by continuous irrigation. The third complication that can occur during revision surgery is related to wounds. Postoperative infection, hematoma, and wound dehiscence occur, resulting in reoperation, use of many antibiotics, and longer hospital stay. Conversely, UBE is associated with fewer back muscle injuries and small wounds, resulting in fewer wound-related problems. Indeed, in our center, patients treated with endoscopy showed few wound-related complications, which were relatively easy to resolve. Postoperative pain was better in the UBE revision group than in the MD revision group. Additionally, postoperative back pain significantly improved in the UBE group before discharge. The number of analgesics administered on the day of surgery was significantly lower in the UBE group. Improvement in radiculopathy was similarly significant in both groups immediately after surgery. However, there were no differences in terms of long-term follow-up (more than 1 month), as back pain and radiculopathy both improved without significant differences between the two groups. The recurrence rate was also higher in both the short- and long-term MD revision groups, without reaching significance due to the low number of recurrence cases. However, in the MD group, one patient experienced two recurrences at 5 and 18 months postoperatively. Although the exact cause is unknown, it can be assumed that there will be an impact on instability due to repeated posterior column injuries such as paraspinal muscle, facet, and wide laminectomies [ 22 ]. The retrospective design and relatively short follow-up period should be considered when interpreting the results of the present study. In addition, the follow-up period between the two groups was somewhat different. The limitations of this study are that only a few patients were enrolled and that it was a single-center study. Therefore, further randomized controlled trials are warranted. UBE revision discectomy had several advantages over MD revision discectomy, including ease of securing the surgical field of view, lower risk of surgery-related complications, and the smaller surgical wound which can reduce the probability of wound-related problems and recurrence. In addition, it had the advantage of a lower rate of immediate postoperative pain, as surgery could be performed without damaging the posterior column. Thus, the present study showed that endoscopic revision surgery might be an alternative to open revision surgery. Declarations Conflict of Interest: The authors declare no conflicts of interest. Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. References Jang JW, Lee DG, Park CK. Rationale, and advantages of endoscopic spine surgery. Int J Spine Surg. 2021;15 Supplement 3:S11–20. https://doi.org/10.14444/8160. 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 in 43 consecutive cases. Spine. 2004;29:E326–32. https://doi.org/10.1097/01.brs.0000134591.32462.98. 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. 2008;33:973–8. https://doi.org/10.1097/BRS.0b013e31816c8ade. Carragee EJ, Spinnickie AO, Alamin TF, Paragioudakis S. A prospective controlled study of limited versus subtotal posterior discectomy: short-term outcomes in patients with herniated lumbar intervertebral discs and large posterior annular defects. Spine. 2006;31:653–7. https://doi.org/10.1097/01.brs.0000203714.76250.68. 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. https://doi.org/10.1302/0301-620x.80b5.8540. Hoogland T, Schubert M, Miklitz B, Ramirez A. Transforaminal posterolateral endoscopic discectomy with or without the combination of a low-dose chymopapain: A prospective randomized study in 280 consecutive cases. Spine. 2006;15;31:E890–7. https://doi.org/10.1097/01.brs.0000245955.22358.3a. Silvers HR, Lewis PJ, Asch HL, Clabeaux DE. Lumbar discectomy for recurrent disc herniation. Clin Spine Surg. 1994;7:408–19. Swartz KR, Trost GR. Recurrent lumbar disc herniation. Neurosurg Focus. 2003;15:E10. https://doi.org/10.3171/foc.2003.15.3.10. Shin BJ. Risk factors for recurrent lumbar disc herniations. Asian Spine J. 2014;8:211–5. https://doi.org/10.4184/asj.2014.8.2.211. Cheng J, Wang H, Zheng W, Li C, Wang J, Zhang Z, Huang B, Zhou Y. Reoperation after lumbar disc surgery in hundred and seven patients. Int Orthop. 2013;37:1511–7. https://doi.org/10.1007/s00264-013-1925-2. 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J Bone Joint Surg Am. 1979;61:201–7. https://doi.org/10.2106/00004623-197961020-00007. Cinotti G, Gumina S, Giannicola G, Postacchini F. Contralateral recurrent lumbar disc herniation: results of discectomy compared with those in primary herniation. Spine. 1999;24:800–6. https://doi.org/10.1097/00007632-199904150-00012. Ozgen S, Naderi S, Ozek MM, Pamir MN. Findings and outcomes of revision lumbar disc surgery. J Spinal Disord. 1999;12:287–92. Vishteh AG, Dickman CA. Anterior lumbar microdiscectomy and interbody fusion for the treatment of recurrent disc herniation. Neurosurgery. 2001;48:334–7; discussion 338. https://doi.org/10.1227/00006123-200102000-00018. Choi KB, Lee DY, Lee SH. Contralateral reherniation after open lumbar microdiscectomy: comparison with ipsilateral reherniation. J Korean Neurosurg Soc. 2008;44:320–6. https://doi.org/10.3340/jkns.2008.44.5.320. Morgan-Hough CV, Jones PW, Eisenstein SM. Primary and revised lumbar discectomies. J Bone Joint Surg Br. 2003;85:871–4. Lee DY, Shim CS, Ahn Y, Kim HJ, Lee SH. Comparison of percutaneous endoscopic and open lumbar microdiscectomy for recurrent disc herniation. J Kor Neurosurg Soc. 2009;46:515–21. https://doi.org/10.3340/jkns.2009.46.6.515. Kang MS, Hwang J-H, Choi DJ, Chung HJ, Lee JH, Kim HN, Park HJ. Clinical outcomes of biportal endoscopic revision lumbar discectomy for recurrent lumbar disc herniation. J Orthop Surg Res. 2020;15:1–9. https://doi.org/10.1186/s13018-020-02087-6. Tables Table 1. Demographic data of the UBE and MD groups UBE group MD group P-value No. of patients 44 46 Sex Male 28 31 Female 16 15 Age (year) 48.93 ± 12.66 (26–79) 52.20 ± 12.35 (30–88) 0.169 Level of surgery L3/4 3 0 L4/5 28 31 L5/S1 13 15 Average follow-up period (months) 2020.03–2023.04 19.09 ± 10.22 2020.03–2023.03 20.45 ± 7.79 <0.0001 Operation time (min) 107.61 ± 35.87 107.50 ± 23.57 0.001 Hospital day (days) 4.57 ± 2.84 7.00 ± 3.91 0.001 Blood loss (ml) 34.09 ± 20.75 41.82 ± 24.13 0.057 UBE, Unilateral biportal endoscopic lumbar discectomy; MD, open lumbar microdiscectomy Table 2: Preoperative and postoperative VAS scores in the UBE and MD groups. UBE group (n = 44) MD group (n = 46) P-value Preoperative VAS Back 6.15 ± 0.25 6.55 ± 1.64 0.561 LEG 7.88 ± 0.65 8.02 ± 0.22 0.765 Immediate postoperative VAS * Back 3.32 ± 0.91 2.81 ± 0.72 0.025 LEG 7.89 ± 1.06 3.02 ± 0.63 <0.0001 POD #1D VAS Back 2.34 ± 0.51 6.74 ± 1.87 0.012 LEG 3.36 ± 0.61 3.73 ± 0.87 0.015 Discharge Day VAS Back 2.85 ± 0.11 4.24 ± 0.44 0.135 LEG 3.05 ± 0.75 2.84 ± 0.56 0.157 POD #1M VAS Back 1.55 ± 0.24 1.98 ± 0.78 0.362 LEG 2.54 ± 1.27 2.50 ± 1.52 0.402 POD #3M VAS Back 1.39 ± 0.89 1.17 ± 0.52 0.759 LEG 2.67 ± 1.72 2.71 ± 1.53 0.536 Last F/U VAS † Back 1.02 ± 0.67 1.45 ± 0.87 0.843 LEG 1.95 ± 0.56 1.78 ± 0.96 1.000 * Average intravenous or intramuscular painkiller use of operative day: UBE = 1.36 ± 0.84, MD = 1.66 ± 1.22 (P < .0001) † Average last follow-up period: UBE = 19.09 ± 10.22 months, MD = 20.45 ± 7.79 months POD, postoperative day; UBE, Unilateral biportal endoscopic lumbar discectomy; MD, open lumbar microdiscectomy; VAS, visual analog scale Table 3. Postoperative recurrence in the UBE and MD groups UBE group (n = 44) MD group (n = 46) Early recurrence (14 days) 1 2 ‡ Recurrence rate 2 (4.55%) 4 (8.7%) ‡ Same patient/revision MD discectomy 2 times (postoperative days 5 months, 18 months) UBE, Unilateral biportal endoscopic lumbar discectomy; MD, open lumbar microdiscectomy Table 4. Postoperative complications in the UBE and MD groups UBE group (n = 44) MD group (n = 46) Dural tear 3 (6.8%) 4 (8.7%) Wound dehiscence 2 1 Postoperative hematoma 1 Complication rate 5 (11.4%) 6 (13.0%) UBE, Unilateral biportal endoscopic lumbar discectomy; MD, open lumbar microdiscectomy Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6141959","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":432719328,"identity":"6c3ffa4e-d8d0-400d-b846-a57464aa0321","order_by":0,"name":"Sang Youp Han","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIiWNgGAWjYBACAwYGxsc/DGp4+NkbQFwLorQwGzNUHJOR7DkA4koQpYVNmuEMs43BjAQQnwgt5vxnjI0L29h4DCSfX93wo0CCgb+9OwGvFssZOYaPZ7bJ8JhL55Td7AE6TOLM2Q34HXaDx9iAF2iL5eyctBs8QC0GErkEtJw/YybB28bMY3DzTNrNP0RpOZBjJs1zBqjlBvux28TZciOt2HBGxTEeyZ4cttsyBhI8hP1y/vDGBx8Mauz52Y8/u/nmj40cf3svfi0MDBwGUAYPmMFDQDkIsD9AZ4yCUTAKRsEoQAUADUNHiVENsfIAAAAASUVORK5CYII=","orcid":"","institution":"The Leon Wiltse Memorial Hospital","correspondingAuthor":true,"prefix":"","firstName":"Sang","middleName":"Youp","lastName":"Han","suffix":""},{"id":432719329,"identity":"036be657-aee3-4b15-b468-853244bb241f","order_by":1,"name":"Sang Hyub Lee","email":"","orcid":"","institution":"The Leon Wiltse Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Sang","middleName":"Hyub","lastName":"Lee","suffix":""},{"id":432719330,"identity":"7ee743c7-63a8-46a2-b5bf-e2cdc60f1793","order_by":2,"name":"Jae-Won Jang","email":"","orcid":"","institution":"The Leon Wiltse Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jae-Won","middleName":"","lastName":"Jang","suffix":""},{"id":432719332,"identity":"149948d5-239b-4e16-a3e8-e884c181ade2","order_by":3,"name":"Dong-Geun Lee","email":"","orcid":"","institution":"The Leon Wiltse Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Dong-Geun","middleName":"","lastName":"Lee","suffix":""},{"id":432719333,"identity":"0a55c53d-d096-4ab7-a088-a417d1fad659","order_by":4,"name":"Yong Eun Cho","email":"","orcid":"","institution":"The Leon Wiltse Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yong","middleName":"Eun","lastName":"Cho","suffix":""},{"id":432719334,"identity":"570b307d-5ce5-4d6f-850b-f098d6ffdd1d","order_by":5,"name":"Choon-Keun Park","email":"","orcid":"","institution":"The Leon Wiltse Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Choon-Keun","middleName":"","lastName":"Park","suffix":""},{"id":432719337,"identity":"3f126a32-8ae3-4012-9568-f879891ddc89","order_by":6,"name":"Il Sup Kim","email":"","orcid":"","institution":"St. Vincent's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Il","middleName":"Sup","lastName":"Kim","suffix":""}],"badges":[],"createdAt":"2025-03-03 02:23:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6141959/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6141959/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":79175664,"identity":"34e8fd7f-c020-4b7e-b8c8-98758d6bab7a","added_by":"auto","created_at":"2025-03-25 09:55:07","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":183325,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative and postoperative VAS score VAS, Visual Analog Scale\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-6141959/v1/dd02563d0896d819b251e479.png"},{"id":79178997,"identity":"a6d97c79-4aa3-42c6-a874-5836456d8aa5","added_by":"auto","created_at":"2025-03-25 10:11:07","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1562845,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of the field of view between the MD and UBE revision surgeries MD, open lumbar microdiscectomy; UBE, Unilateral biportal endoscopic lumbar discectomy\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-6141959/v1/f530ba0e302105820a21936b.png"},{"id":79180853,"identity":"8b9f5f8c-f025-469a-af64-8d6dd45fe987","added_by":"auto","created_at":"2025-03-25 10:27:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3993212,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6141959/v1/9ea5458a-dd0b-4a7d-8462-c03138d4a50c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eFeasibility of recurrent herniation surgery with biportal endoscopic discectomy:A comparison of biportal endoscopic discectomy and microscopic discectomy for recurrent disc herniation\u003c/p\u003e","fulltext":[{"header":"1. INTRODUCTION","content":"\u003cp\u003eSeveral studies have demonstrated the advantages of unilateral biportal endoscopic (UBE) surgery. This endoscopic discectomy reduces postoperative pain, due to small wounds, and complications such as incidental durotomy and neural injury during surgery with good surgical vision [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In addition, postoperative instability is prevented by preserving the lumbar posterior columns with less infection after surgery. However, few studies have investigated the benefits of biportal endoscopic revision discectomy.\u003c/p\u003e \u003cp\u003eSeveral studies comparing surgery through revision percutaneous endoscopic lumbar discectomy (PELD) and microscopic revision discectomy (MD) showed the numerous benefits of PELD [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, few studies have compared the clinical outcomes of UBE and MD. To address this knowledge gap, in the present study, we compared the serial pain outcomes in patients who underwent UBE and MD and compared the associated complication and recurrence rates.\u003c/p\u003e"},{"header":"2. METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e\u003cb\u003e2.1.\u003c/b\u003e \u003cem\u003ePatients\u003c/em\u003e\u003c/h2\u003e \u003cp\u003ePatients who underwent surgery at our hospital between March 2020 and April 2023 were examined for the recurrence of herniated nucleus pulposus. This cohort included 44 and 46 patients who underwent UBE and MD, respectively. Nine skilled surgeons, all were experts in both UBE and MD, performed all surgeries.\u003c/p\u003e \u003cp\u003e Demographic characteristics, time interval since previous surgery, operative level, length of hospital stay, blood loss, and operative time were reviewed. Regarding clinical evaluation, visual analog scale (VAS) scores for the operation site and radiating pain were measured before and after surgery. Preoperative and postoperative radiological images (radiography and magnetic resonance imaging [MRI]) were routinely taken one day after surgery and compared. Data analysis was performed using SPSS ver 28.0 (SPSS Inc., Chicago, IL, USA).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e\u003cem\u003e2.2. Indications and inclusion/exclusion criteria\u003c/em\u003e\u003c/h2\u003e \u003cp\u003ePatients with single-level radiculopathy or lower back pain caused by reherniated discs were enrolled. Only patients who underwent open microscopic discectomy for a period of more than six months without symptoms were included. This study was approved by the Institutional Review Board (approval no.: 2023-W09) of the Wiltse Memorial Hospital Spine Center. Patients with multilevel symptoms, ambiguous symptoms, previous fusion surgery, calcified discs, severe neurological deficits, or instability were excluded.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Preoperative and postoperative evaluation\u003c/h2\u003e \u003cp\u003eVAS scores were calculated preoperatively; immediate postoperatively; one day postoperatively; at discharge (average: UBE\u0026thinsp;=\u0026thinsp;4.57\u0026thinsp;\u0026plusmn;\u0026thinsp;2.84 days, MD\u0026thinsp;=\u0026thinsp;7.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.91 days); and at 1 and 3 months postoperatively. The number of intravenous and intramuscular painkillers administered on the day of surgery was also compared between the two groups. Painkillers were counted as the number of intravenous bolus paracetamol (Profa infusion 75 mL, Dai Han Pharma Korea Ltd., Seoul, Korea), intramuscular pethidine 25 mg, and tramadol 50 mg injections.\u003c/p\u003e \u003cp\u003eThe recurrence rate after surgery was divided into early and late stages, with the cutoff set at 14 days after surgery. Postoperative complications were also assessed.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4. Operation procedures\u003c/h2\u003e \u003cp\u003eAll surgeries were performed under general or epidural anesthesia. The patients were placed in the prone position. Two holes were created on the ipsilateral side using a C-arm, with location based on the pedicle line above and below the disc space, 1 cm outside the midline (usually near the medial pedicle line). Location changed slightly, depending on the case. The surgeon\u0026rsquo;s right portal was usually located as a working portal, either to the left (0.5 cm) or right as 1.0 cm, and an incision was performed.\u003c/p\u003e \u003cp\u003eAfter identifying the laminar and inferior articular processes, lateral decompression was performed using a high-speed diamond drill (no-cutting drill). Care was taken, as the ligamentum flavum may have been removed during a previous surgery. Neural tissue margins were secured through sufficient drilling. If the instrument was squeezed into a narrow space, the chances of a durotomy or neural damage were high.\u003c/p\u003e \u003cp\u003eOnce the surgical anatomy was confirmed, surgery was performed by thinning the inner bone by approximately 1 mm and carefully removing it using a curette, rather than directly drilling the inner cortical bone attached to the adhesion tissue. After removing the adhesion tissue, normal neural tissue was observed. This could be peeled off from the virgin area of the cranial part without durotomy, if required. After sufficient neural tissue exposure, the ventral adhesion was peeled off, and root retraction was performed for discectomy. If the adhesion was very severe, a lateral annulotomy was performed to secure space by internal decompression and gradually release the adhesion. After removing the disc fragment, the remnant disc around the torn disc was examined. Remnant discs could be more effectively removed using the Valsalva maneuver. After sufficient neural decompression, bleeding control, JP drain insertion, and surgery were performed.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. RESULTS","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Patients\u003c/h2\u003e \u003cp\u003eNinety patients were enrolled in this study, of whom 44 underwent UBE and 46 underwent MD. The mean age of the patients undergoing UBE was 48.9 years old (28 men and 16 women; range: 26\u0026ndash;79), and that of the patients treated with MD was 52.2 years old (31 men and 15 women; range 30\u0026ndash;88), showing almost the same pattern. The most common surgical level in both groups was L4/5 (UBE\u0026thinsp;=\u0026thinsp;61.3%, MD\u0026thinsp;=\u0026thinsp;67.3%). The mean follow-up periods were 19.09\u0026thinsp;\u0026plusmn;\u0026thinsp;10.22 in the UBE group and 20.45\u0026thinsp;\u0026plusmn;\u0026thinsp;7.79 in the MD group (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026le;\u0026thinsp;.0001). All surgeries were performed from March 2020 to March 2023. Demographic data are presented in Table\u0026nbsp;1.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Clinical outcomes\u003c/h2\u003e \u003cp\u003eThe mean operation time was similar in both groups (UBE\u0026thinsp;=\u0026thinsp;107.61\u0026thinsp;\u0026plusmn;\u0026thinsp;35.87 minutes, MD\u0026thinsp;=\u0026thinsp;107.50\u0026thinsp;\u0026plusmn;\u0026thinsp;23.57 minutes, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026le;\u0026thinsp;.0001). However, the hospital length of stay was significantly shorter in the UBE group than in the MD group (UBE\u0026thinsp;=\u0026thinsp;4.57\u0026thinsp;\u0026plusmn;\u0026thinsp;2.84 days, MD\u0026thinsp;=\u0026thinsp;7.0\u0026thinsp;\u0026plusmn;\u0026thinsp;3.91 days, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.169). The bleeding loss was also shorter in the UBE group (UBE\u0026thinsp;=\u0026thinsp;34.09\u0026thinsp;\u0026plusmn;\u0026thinsp;20.75 ml, MD\u0026thinsp;=\u0026thinsp;41.82\u0026thinsp;\u0026plusmn;\u0026thinsp;24.13 ml, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0569), without showing significant difference.\u003c/p\u003e \u003cp\u003eThere was no significant difference in the preoperative pain between the groups. However, there was a significant difference in postoperative back pain (VAS score: UBE\u0026thinsp;=\u0026thinsp;3.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91, MD\u0026thinsp;=\u0026thinsp;7.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.06, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.561). In addition, the number of painkillers used on the day of surgery was also confirmed to be higher in the MD group than in the UBE group (MD\u0026thinsp;=\u0026thinsp;1.66\u0026thinsp;\u0026plusmn;\u0026thinsp;1.22, UBE\u0026thinsp;=\u0026thinsp;1.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.84, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026le;\u0026thinsp;.0001). This difference in back pain continued until discharge. However, there was no difference between the two groups in the long term after 1 month. Postoperative radiating pain significantly improved in both groups without significant differences (Table\u0026nbsp;2, Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e3.3 Recurrence and complications\u003c/h2\u003e \u003cp\u003eRecurrence after surgery was classified as either early or late (with 14 days as the cutoff). Early recurrence occurred in one case in the UBE group and two cases in the MD group. Late recurrence occurred in one patient in the UBE group (postoperative day 6 months) and twice in one patient in the MD group (5 and 18 months postoperatively). Patients in the UBE group underwent fusion surgery, and those in the MD group underwent MD twice. The overall recurrence rates were 4.55% and 8.7% in the UBE and MD groups, respectively (Table\u0026nbsp;3).\u003c/p\u003e \u003cp\u003eDural tears occurred in three patients in the UBE group and four patients in the MD group. In all cases, the patients recovered after conservative treatment using primary sutures. In addition, the UBE group was treated with peroral antibiotics and re-sutured because of the occurrence of wound dehiscence in two cases. The MD group underwent aspiration and re-suture due to the occurrence of wound dehiscence in one patient, while hematoma removal was performed due to postoperative hematoma. No major complications such as wound infection or nerve tissue damage occurred in any of the patients (Table\u0026nbsp;4).\u003c/p\u003e \u003c/div\u003e"},{"header":"4. CONCLUSIONS","content":"\u003cp\u003eRecurrent disc herniation is a common complication after lumbar discectomy, occurring in 5\u0026ndash;18% of patients [\u003cspan additionalcitationids=\"CR5 CR6 CR7\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In addition, the rate of surgical treatment of recurrent disc herniation is quite high at, approximately 62% [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Of note, the results of revision lumbar discectomy have been reported to be favorable [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. However, patients experience discomfort during the process.\u003c/p\u003e \u003cp\u003eIn addition, revision surgery for recurrent disc herniation is more difficult and associated with a higher rate of complications than is virgin surgery. Scar tissue usually makes repeat microscopic discectomy more difficult and increases the risk of dural tears and/or nerve root injury [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan additionalcitationids=\"CR15 CR16 CR17\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. The incidence of dural tears during repeat microscopic discectomy has been reported in up to 20% of patients [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Experienced surgeons can also perform durotomy when performing adhesiolysis. Durotomy increases hospital stay, while cerebral nervous system infection can cause fetal problems. In addition, maintaining absolute bed rest or lumbar drain insertion for durotomy causes discomfort among patients. However, surgery using an endoscope can reduce patient discomfort, lower the complication rate by magnifying surgical vision, and reduce posterior column damage [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Lee et al. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] previously reported that the complication rate was lower than that of MD (UBE\u0026thinsp;=\u0026thinsp;4% vs. MD\u0026thinsp;=\u0026thinsp;10.3%) when revision surgery was performed using PELD. In addition, two cases of durotomy occurred only in the MD revision group (UBE\u0026thinsp;=\u0026thinsp;0% vs. MD\u0026thinsp;=\u0026thinsp;6.9%). Kang et al. [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] reported that UBE revision surgery provided faster pain relief and earlier functional recovery than did MD revision surgery. This study also showed that the immediate postoperative outcome was better than that of MD. Moreover, the results of long-term follow-up over six weeks were similar in both groups. Additionally, the incidence of incidental durotomy was lower than that of MD (6.3% vs. 10%).\u003c/p\u003e \u003cp\u003eThis study also confirmed that the UBE group had a lower incidence of durotomy than did the MD group (UBE\u0026thinsp;=\u0026thinsp;6.8% vs. MD\u0026thinsp;=\u0026thinsp;8.7%). Importantly, since the number of durotomy procedures was small and there was only one case, this difference did not reach significance. However, durotomies occurred less frequently.\u003c/p\u003e \u003cp\u003eThe surgical field of view achieved during UBE is much better than that achieved using a microscope; the possibility of incidental durotomy can be reduced as it can be performed by checking for blind spots that cannot be seen under a microscope. In addition, when MD is performed, venous bleeding may occur; the surgical field of view may be obscured as there is no venous bleeding due to water pressure with UBE. This technique also has the advantage of keeping the surgical field clean (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). However, if a durotomy is performed during UBE surgery, serious problems can arise. When water flows into the durotomy site, the intracranial pressure increases, causing neurological deterioration. Symptoms such as seizures or mental retardation may occur. As such, completing the operation as soon as possible if a durotomy occurs is necessary. Furthermore, the surgical method should be changed to conventional microscopic discectomy if the operation is prolonged.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eNeural tissue damage is another complication that may occur during revision surgery is. Since the ligamentum flavum had already been removed, the neural tissue is immediately exposed without protection. Neural tissue damage can occur when a mistake is made during the bone drilling process or when a punch is used. However, improvements in the field of view can reduce the likelihood of neural damage; as such, UBE is associated with a lower risk of neural damage because the nerves are sunken due to water pressure. In addition, this water pressure facilitates adhesiolysis, and thermal damage is reduced by continuous irrigation.\u003c/p\u003e \u003cp\u003eThe third complication that can occur during revision surgery is related to wounds. Postoperative infection, hematoma, and wound dehiscence occur, resulting in reoperation, use of many antibiotics, and longer hospital stay. Conversely, UBE is associated with fewer back muscle injuries and small wounds, resulting in fewer wound-related problems. Indeed, in our center, patients treated with endoscopy showed few wound-related complications, which were relatively easy to resolve.\u003c/p\u003e \u003cp\u003ePostoperative pain was better in the UBE revision group than in the MD revision group. Additionally, postoperative back pain significantly improved in the UBE group before discharge. The number of analgesics administered on the day of surgery was significantly lower in the UBE group. Improvement in radiculopathy was similarly significant in both groups immediately after surgery. However, there were no differences in terms of long-term follow-up (more than 1 month), as back pain and radiculopathy both improved without significant differences between the two groups.\u003c/p\u003e \u003cp\u003eThe recurrence rate was also higher in both the short- and long-term MD revision groups, without reaching significance due to the low number of recurrence cases. However, in the MD group, one patient experienced two recurrences at 5 and 18 months postoperatively. Although the exact cause is unknown, it can be assumed that there will be an impact on instability due to repeated posterior column injuries such as paraspinal muscle, facet, and wide laminectomies [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe retrospective design and relatively short follow-up period should be considered when interpreting the results of the present study. In addition, the follow-up period between the two groups was somewhat different. The limitations of this study are that only a few patients were enrolled and that it was a single-center study. Therefore, further randomized controlled trials are warranted.\u003c/p\u003e \u003cp\u003eUBE revision discectomy had several advantages over MD revision discectomy, including ease of securing the surgical field of view, lower risk of surgery-related complications, and the smaller surgical wound which can reduce the probability of wound-related problems and recurrence. In addition, it had the advantage of a lower rate of immediate postoperative pain, as surgery could be performed without damaging the posterior column. Thus, the present study showed that endoscopic revision surgery might be an alternative to open revision surgery.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConflict of Interest:\u003c/strong\u003e The authors declare no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003eThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eJang JW, Lee DG, Park CK. Rationale, and advantages of endoscopic spine surgery. Int J Spine Surg. 2021;15 Supplement 3:S11\u0026ndash;20. https://doi.org/10.14444/8160.\u003c/li\u003e\n\u003cli\u003eAhn 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 in 43 consecutive cases. Spine. 2004;29:E326\u0026ndash;32. https://doi.org/10.1097/01.brs.0000134591.32462.98.\u003c/li\u003e\n\u003cli\u003eHoogland 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. 2008;33:973\u0026ndash;8. https://doi.org/10.1097/BRS.0b013e31816c8ade.\u003c/li\u003e\n\u003cli\u003eCarragee EJ, Spinnickie AO, Alamin TF, Paragioudakis S. A prospective controlled study of limited versus subtotal posterior discectomy: short-term outcomes in patients with herniated lumbar intervertebral discs and large posterior annular defects. Spine. 2006;31:653\u0026ndash;7. https://doi.org/10.1097/01.brs.0000203714.76250.68.\u003c/li\u003e\n\u003cli\u003eCinotti G, Roysam GS, Eisenstein SM, Postacchini F. Ipsilateral recurrent lumbar disc herniation: a prospective, controlled study. J Bone Joint Surg Br. 1998;80:825\u0026ndash;32. https://doi.org/10.1302/0301-620x.80b5.8540.\u003c/li\u003e\n\u003cli\u003eHoogland T, Schubert M, Miklitz B, Ramirez A. Transforaminal posterolateral endoscopic discectomy with or without the combination of a low-dose chymopapain: A prospective randomized study in 280 consecutive cases. Spine. 2006;15;31:E890\u0026ndash;7. https://doi.org/10.1097/01.brs.0000245955.22358.3a.\u003c/li\u003e\n\u003cli\u003eSilvers HR, Lewis PJ, Asch HL, Clabeaux DE. Lumbar discectomy for recurrent disc herniation. Clin Spine Surg. 1994;7:408\u0026ndash;19.\u003c/li\u003e\n\u003cli\u003eSwartz KR, Trost GR. Recurrent lumbar disc herniation. Neurosurg Focus. 2003;15:E10. https://doi.org/10.3171/foc.2003.15.3.10.\u003c/li\u003e\n\u003cli\u003eShin BJ. Risk factors for recurrent lumbar disc herniations. Asian Spine J. 2014;8:211\u0026ndash;5. https://doi.org/10.4184/asj.2014.8.2.211.\u003c/li\u003e\n\u003cli\u003eCheng J, Wang H, Zheng W, Li C, Wang J, Zhang Z, Huang B, Zhou Y. Reoperation after lumbar disc surgery in hundred and seven patients. Int Orthop. 2013;37:1511\u0026ndash;7. https://doi.org/10.1007/s00264-013-1925-2.\u003c/li\u003e\n\u003cli\u003eLebow RL, Adogwa O, Parker SL, Sharma A, Cheng J, McGirt MJ. Asymptomatic same-site recurrent disc herniation after lumbar discectomy: results of a prospective longitudinal study with 2-year serial imaging. Spine. 2011;36:2147\u0026ndash;51. https://doi.org/10.1097/BRS.0b013e3182054595.\u003c/li\u003e\n\u003cli\u003eYoshihara H, Chatterjee D, Paulino CB, Errico TJ. Revision surgery for \u0026ldquo;real\u0026rdquo; recurrent lumbar disk herniation: a systematic review. Clin Spine Surg. 2016;29:111\u0026ndash;8. https://doi.org/10.1097/BSD.0000000000000365.\u003c/li\u003e\n\u003cli\u003eIlyas H, Savage J. Lumbar disc herniation and SPORT: a review of the literature. Clin Spine Surg. 2018;31:366\u0026ndash;72. https://doi.org/10.1097/BSD.0000000000000696.\u003c/li\u003e\n\u003cli\u003eKim SS, Michelsen CB. Revision surgery for failed back surgery syndrome. Spine. 1992;17:957\u0026ndash;60. https://doi.org/10.1097/00007632-199208000-00015.\u003c/li\u003e\n\u003cli\u003eWaddell G, Kummel EG, Lotto WN, Graham JD, Hall H, McCulloch JA. Failed lumbar disc surgery and repeat surgery following industrial injuries. J Bone Joint Surg Am. 1979;61:201\u0026ndash;7. https://doi.org/10.2106/00004623-197961020-00007.\u003c/li\u003e\n\u003cli\u003eCinotti G, Gumina S, Giannicola G, Postacchini F. Contralateral recurrent lumbar disc herniation: results of discectomy compared with those in primary herniation. Spine. 1999;24:800\u0026ndash;6. https://doi.org/10.1097/00007632-199904150-00012.\u003c/li\u003e\n\u003cli\u003eOzgen S, Naderi S, Ozek MM, Pamir MN. Findings and outcomes of revision lumbar disc surgery. J Spinal Disord. 1999;12:287\u0026ndash;92.\u003c/li\u003e\n\u003cli\u003eVishteh AG, Dickman CA. Anterior lumbar microdiscectomy and interbody fusion for the treatment of recurrent disc herniation. Neurosurgery. 2001;48:334\u0026ndash;7; discussion 338. https://doi.org/10.1227/00006123-200102000-00018.\u003c/li\u003e\n\u003cli\u003eChoi KB, Lee DY, Lee SH. Contralateral reherniation after open lumbar microdiscectomy: comparison with ipsilateral reherniation. J Korean Neurosurg Soc. 2008;44:320\u0026ndash;6. https://doi.org/10.3340/jkns.2008.44.5.320.\u003c/li\u003e\n\u003cli\u003eMorgan-Hough CV, Jones PW, Eisenstein SM. Primary and revised lumbar discectomies. J Bone Joint Surg Br. 2003;85:871\u0026ndash;4.\u003c/li\u003e\n\u003cli\u003eLee DY, Shim CS, Ahn Y, Kim HJ, Lee SH. Comparison of percutaneous endoscopic and open lumbar microdiscectomy for recurrent disc herniation. J Kor Neurosurg Soc. 2009;46:515\u0026ndash;21. https://doi.org/10.3340/jkns.2009.46.6.515.\u003c/li\u003e\n\u003cli\u003eKang MS, Hwang J-H, Choi DJ, Chung HJ, Lee JH, Kim HN, Park HJ. Clinical outcomes of biportal endoscopic revision lumbar discectomy for recurrent lumbar disc herniation. J Orthop Surg Res. 2020;15:1\u0026ndash;9. https://doi.org/10.1186/s13018-020-02087-6.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1. Demographic data of the UBE and MD groups\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"648\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003eUBE group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003eMD group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003eP-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eNo. of patients\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 38px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 162px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eAge (year)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e48.93 \u0026plusmn; 12.66 (26\u0026ndash;79)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e52.20 \u0026plusmn; 12.35 (30\u0026ndash;88)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e0.169\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eLevel of surgery\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eL3/4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eL4/5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eL5/S1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eAverage follow-up period (months)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e2020.03\u0026ndash;2023.04\u003c/p\u003e\n \u003cp\u003e19.09 \u0026plusmn; 10.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e2020.03\u0026ndash;2023.03\u003c/p\u003e\n \u003cp\u003e20.45 \u0026plusmn; 7.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e\u0026lt;0.0001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eOperation time (min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e107.61 \u0026plusmn; 35.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e107.50 \u0026plusmn; 23.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eHospital day (days)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e4.57 \u0026plusmn; 2.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e7.00 \u0026plusmn; 3.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 200px;\"\u003e\n \u003cp\u003eBlood loss (ml)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e34.09 \u0026plusmn; 20.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e41.82 \u0026plusmn; 24.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 64px;\"\u003e\n \u003cp\u003e0.057\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eUBE, Unilateral biportal endoscopic lumbar discectomy; MD, open lumbar microdiscectomy\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Table 2: Preoperative and postoperative VAS scores in the UBE and MD groups.\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"647\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 124px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003eUBE group\u003c/p\u003e\n \u003cp\u003e(n = 44)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003eMD group\u003c/p\u003e\n \u003cp\u003e(n = 46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003eP-value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 124px;\"\u003e\n \u003cp\u003ePreoperative\u003c/p\u003e\n \u003cp\u003eVAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eBack\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e6.15 \u0026plusmn; 0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e6.55 \u0026plusmn; 1.64\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.561\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e7.88 \u0026plusmn; 0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e8.02 \u0026plusmn; 0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.765\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 124px;\"\u003e\n \u003cp\u003eImmediate postoperative VAS\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eBack\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e3.32 \u0026plusmn; 0.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e2.81 \u0026plusmn; 0.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.025\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e7.89 \u0026plusmn; 1.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e3.02 \u0026plusmn; 0.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u0026lt;0.0001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 124px;\"\u003e\n \u003cp\u003ePOD #1D\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eVAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eBack\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e2.34 \u0026plusmn; 0.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e6.74 \u0026plusmn; 1.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.012\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e3.36 \u0026plusmn; 0.61\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e3.73 \u0026plusmn; 0.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.015\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 124px;\"\u003e\n \u003cp\u003eDischarge Day\u003c/p\u003e\n \u003cp\u003eVAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eBack\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e2.85 \u0026plusmn; 0.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e4.24 \u0026plusmn; 0.44\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.135\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e3.05 \u0026plusmn; 0.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e2.84 \u0026plusmn; 0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.157\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 124px;\"\u003e\n \u003cp\u003ePOD #1M\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eVAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eBack\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e1.55 \u0026plusmn; 0.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e1.98 \u0026plusmn; 0.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.362\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e2.54 \u0026plusmn; 1.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e2.50 \u0026plusmn; 1.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.402\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 124px;\"\u003e\n \u003cp\u003ePOD #3M\u003c/p\u003e\n \u003cp\u003eVAS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eBack\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e1.39 \u0026plusmn; 0.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e1.17 \u0026plusmn; 0.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.759\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e2.67 \u0026plusmn; 1.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e2.71 \u0026plusmn; 1.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.536\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 124px;\"\u003e\n \u003cp\u003eLast F/U\u003cbr\u003eVAS\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eBack\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e1.02 \u0026plusmn; 0.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e1.45 \u0026plusmn; 0.87\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.843\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLEG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 185px;\"\u003e\n \u003cp\u003e1.95 \u0026plusmn; 0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e1.78 \u0026plusmn; 0.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003e*\u003c/sup\u003eAverage intravenous or intramuscular painkiller use of operative day: UBE = 1.36 \u0026plusmn; 0.84, MD = 1.66 \u0026plusmn; 1.22 (P \u0026lt; .0001)\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e\u0026dagger;\u003c/sup\u003eAverage last follow-up period: UBE = 19.09 \u0026plusmn; 10.22 months, MD = 20.45 \u0026plusmn; 7.79 months\u003c/p\u003e\n\u003cp\u003ePOD, postoperative day; UBE, Unilateral biportal endoscopic lumbar discectomy; MD, open lumbar microdiscectomy; VAS, visual analog scale\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eTable 3. Postoperative recurrence in the UBE and MD groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"602\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 262px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003eUBE group (n = 44)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003eMD group (n = 46)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 262px;\"\u003e\n \u003cp\u003eEarly recurrence (\u0026lt;14 days)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 262px;\"\u003e\n \u003cp\u003eLate recurrence (\u0026gt;14 days)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e2\u003csup\u003e\u0026Dagger;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 262px;\"\u003e\n \u003cp\u003e\u0026nbsp;Recurrence rate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 174px;\"\u003e\n \u003cp\u003e2 (4.55%)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e4 (8.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003csup\u003e\u0026Dagger;\u003c/sup\u003eSame patient/revision MD discectomy 2 times (postoperative days 5 months, 18 months)\u003c/p\u003e\n\u003cp\u003eUBE, Unilateral biportal endoscopic lumbar discectomy; MD, open lumbar microdiscectomy\u003c/p\u003e\n\u003cp\u003eTable 4. Postoperative complications in the UBE and MD groups\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"602\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 237px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 187px;\"\u003e\n \u003cp\u003eUBE group (n = 44)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 178px;\"\u003e\n \u003cp\u003eMD group (n = 46)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 237px;\"\u003e\n \u003cp\u003eDural tear\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 187px;\"\u003e\n \u003cp\u003e3 (6.8%)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 178px;\"\u003e\n \u003cp\u003e4 (8.7%)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 237px;\"\u003e\n \u003cp\u003eWound dehiscence\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 187px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 178px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 237px;\"\u003e\n \u003cp\u003ePostoperative hematoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 187px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 178px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 237px;\"\u003e\n \u003cp\u003eComplication rate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 187px;\"\u003e\n \u003cp\u003e5 (11.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 178px;\"\u003e\n \u003cp\u003e6 (13.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eUBE, Unilateral biportal endoscopic lumbar discectomy; MD, open lumbar microdiscectomy\u003c/p\u003e\n"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"revision surgery, discectomy, endoscopy, disc herniation","lastPublishedDoi":"10.21203/rs.3.rs-6141959/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6141959/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cem\u003eBackground\u003c/em\u003e\u003cstrong\u003e: \u003c/strong\u003eIn this study, we aimed to compare the clinical outcomes of unilateral biportal endoscopic lumbar discectomy (UBE) and open lumbar microdiscectomy (MD) for recurrent disc herniation.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eMethods \u003c/em\u003e\u003cstrong\u003e: \u003c/strong\u003eNinety patients who underwent discectomy, including 44 and 46 who underwent UBE and MD, respectively, were enrolled. All surgeries were performed between March 2020 and April 2023. Only patients with single-level recurrence were included; patients with multilevel recurrence or unstable disease, as well as those who had undergone surgery less than 6 months prior, were excluded. Visual Analog Scale (VAS) scores, recurrence rates, and complications were compared between the groups.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eResults\u003c/em\u003e\u003cstrong\u003e: \u003c/strong\u003eThe average follow-up periods were 19.09 months and 20.45 months in the UBE revision and MD revision discectomy groups, respectively. The mean bleeding loss and hospital stay were significantly shorter in the UBE group than in the MD group. Postoperative short-term back pain was significantly lower in the UBE group (VAS score, 3.32) than in the MD group (VAS score, 7.89). Radiating pain showed similar patterns in both groups at all time points. The recurrence rates were 4.55% and 8.7% in the UBE and MD groups, respectively. Regarding complications, 3 (6.81%) and 4 (8.7%) patients experienced dural tears in the UBE and MD revision groups, respectively.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eConclusion\u003c/em\u003e\u003cstrong\u003e: \u003c/strong\u003eBoth UBE and MD could achieve good long-term outcomes; however, UBE revision was superior in terms of short-term back pain, bleeding loss, and length of hospital stay after surgery.\u003c/p\u003e","manuscriptTitle":"Feasibility of recurrent herniation surgery with biportal endoscopic discectomy:A comparison of biportal endoscopic discectomy and microscopic discectomy for recurrent disc herniation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-03-25 09:55:02","doi":"10.21203/rs.3.rs-6141959/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"fb5415ab-f8da-4b0a-a8f8-199a51468353","owner":[],"postedDate":"March 25th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-03-25T09:55:05+00:00","versionOfRecord":[],"versionCreatedAt":"2025-03-25 09:55:02","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6141959","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6141959","identity":"rs-6141959","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}