{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,11]],"date-time":"2026-04-11T02:01:48Z","timestamp":1775872908127,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2025,9,12]],"date-time":"2025-09-12T00:00:00Z","timestamp":1757635200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Objectives: Transforaminal endoscopic lumbar foraminotomy (TELF) is an emerging minimally invasive surgical technique for lumbar foraminal stenosis. However, its effectiveness is debated because of concerns regarding adequate decompression and its long-term consistency. This study introduced the extended form of TELF, an advanced technique, to provide more extensive decompression using the same approach. Thus, this study aimed to describe the surgical technique and clinical outcomes of this technique. Methods: This retrospective cohort study included patients who underwent conventional (n = 67) or extended (n = 64) TELF. The surgical procedure involved a transforaminal approach with endoscopic decompression, including the removal of the tip of the superior articular process, foraminal ligament, and ligamentum flavum (conventional group), or additional decompression, involving the isthmus and portions of the superior and inferior pedicle walls (extended group). Clinical outcomes were assessed using the visual analog pain scale, Oswestry disability index, and modified Macnab criteria. Results: Despite the longer surgical duration, the extended TELF group tended to show better outcomes in terms of the VAS and ODI scores at the early and final 2-year follow-ups (p &lt; 0.05). The overall success rates were 92.19% and 85.07% in the extended and conventional groups, respectively. No difference was observed in surgical complications between the two groups. Conclusions: Extended TELF, a refined endoscopic technique, achieves better effects than conventional TELF with a lower risk of nerve root irritation by creating a sufficiently safe resection margin. The results support the use of an extended TELF as an advanced form of endoscopic foraminal decompression.<\/jats:p>","DOI":"10.3390\/jcm14186446","type":"journal-article","created":{"date-parts":[[2025,9,12]],"date-time":"2025-09-12T13:43:02Z","timestamp":1757684582000},"page":"6446","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Clinical Efficacy of Extended Transforaminal Endoscopic Lumbar Foraminotomy Compared with the Conventional Technique"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3262-1672","authenticated-orcid":false,"given":"Yong","family":"Ahn","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, Kyung Hee University Hospital at Gangdong, Kyung Hee University College of Medicine, Seoul 05278, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1630-7595","authenticated-orcid":false,"given":"Han-Byeol","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Gachon University Gil Medical Center, Incheon 21565, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2815-9908","authenticated-orcid":false,"given":"Seong","family":"Son","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Gachon University Gil Medical Center, Incheon 21565, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5696-5931","authenticated-orcid":false,"given":"Byung-Rhae","family":"Yoo","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Gachon University Gil Medical Center, Incheon 21565, Republic of Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1055\/s-2008-1052006","article-title":"Endoscopic laser foraminoplasty on the lumbar spine\u2014Early experience","volume":"41","author":"Knight","year":"1998","journal-title":"Minim. Invasive Neurosurg."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1097\/00007632-200002010-00022","article-title":"Spine update. Lumbar foraminal stenosis","volume":"25","author":"Jenis","year":"2000","journal-title":"Spine"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"754","DOI":"10.3171\/jns.1991.74.5.0754","article-title":"Unilateral facetectomy approach for lateral lumbar disc herniation","volume":"74","author":"Garrido","year":"1991","journal-title":"J. Neurosurg."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1312","DOI":"10.1097\/00007632-199111000-00012","article-title":"Diagnosis and operative treatment of intraforaminal and extraforaminal nerve root compression","volume":"16","author":"Kunogi","year":"1991","journal-title":"Spine"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1163","DOI":"10.1097\/01.brs.0000216431.69359.91","article-title":"Risk factor for unsatisfactory outcome after lumbar foraminal and far lateral microdecompression","volume":"31","author":"Chang","year":"2006","journal-title":"Spine"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"973","DOI":"10.1097\/00007632-200104150-00025","article-title":"Long-term complications in adult spinal deformity patients having combined surgery a comparison of primary to revision patients","volume":"26","author":"Lapp","year":"2001","journal-title":"Spine"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"818","DOI":"10.1097\/00007632-200204150-00008","article-title":"Factors predicting hospital stay, operative time, blood loss, and transfusion in patients undergoing revision posterior lumbar spine decompression, fusion, and segmental instrumentation","volume":"27","author":"Zheng","year":"2002","journal-title":"Spine"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"E770","DOI":"10.1097\/BSD.0000000000000391","article-title":"Predicting postoperative morbidity and readmission for revision posterior lumbar fusion","volume":"30","author":"Basques","year":"2017","journal-title":"Clin. Spine Surg."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Miscusi, M., Trungu, S., Ricciardi, L., Forcato, S., Piazza, A., Ramieri, A., and Raco, A. (2023). Stand-alone oblique lumbar interbody fusion (OLIF) for the treatment of adjacent segment disease (ASD) after previous posterior lumbar fusion: Clinical and radiological outcomes and comparison with posterior revision surgery. J. Clin. Med., 12.","DOI":"10.3390\/jcm12082985"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"216","DOI":"10.3171\/jns.1993.78.2.0216","article-title":"Percutaneous endoscopic discectomy: Surgical technique and preliminary results compared to microsurgical discectomy","volume":"78","author":"Mayer","year":"1993","journal-title":"J. Neurosurg."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"958","DOI":"10.2106\/00004623-199907000-00008","article-title":"A prospective, randomized study comparing the results of open discectomy with those of video-assisted arthroscopic microdiscectomy","volume":"81","author":"Hermantin","year":"1999","journal-title":"J. Bone Jt. Surg. Am."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"E890","DOI":"10.1097\/01.brs.0000245955.22358.3a","article-title":"Transforaminal posterolateral endoscopic discectomy with or without the combination of a low-dose chymopapain: A prospective randomized study in 280 consecutive cases","volume":"31","author":"Hoogland","year":"2006","journal-title":"Spine"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"931","DOI":"10.1097\/BRS.0b013e31816c8af7","article-title":"Full-endoscopic interlaminar and transforaminal lumbar discectomy versus conventional microsurgical technique: A prospective, randomized, controlled study","volume":"33","author":"Ruetten","year":"2008","journal-title":"Spine"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1097\/BSD.0b013e318175ddb4","article-title":"Recurrent lumbar disc herniation after conventional discectomy: A prospective, randomized study comparing full-endoscopic interlaminar and transforaminal versus microsurgical revision","volume":"22","author":"Ruetten","year":"2009","journal-title":"J. Spinal Disord. Tech."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"72","DOI":"10.14444\/7010","article-title":"Percutaneous endoscopic lumbar discectomy versus microdiscectomy for the treatment of lumbar disc herniation: Pain, disability, and complication rate\u2014A randomized clinical trial","volume":"14","author":"Meyer","year":"2020","journal-title":"Int. J. Spine Surg."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"847","DOI":"10.1007\/s00586-016-4885-6","article-title":"A randomised controlled trial of transforaminal endoscopic discectomy vs. microdiscectomy","volume":"26","author":"Gibson","year":"2017","journal-title":"Eur. Spine J."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1007\/s00586-009-1155-x","article-title":"Transforaminal endoscopic surgery for symptomatic lumbar disc herniations: A systematic review of the literature","volume":"19","author":"Nellensteijn","year":"2010","journal-title":"Eur. Spine J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1007\/s00586-015-3776-6","article-title":"A meta-analysis of endoscopic discectomy versus open discectomy for symptomatic lumbar disk herniation","volume":"25","author":"Cong","year":"2016","journal-title":"Eur. Spine J."},{"key":"ref_19","first-page":"103","article-title":"Full-Endoscopic procedures versus traditional discectomy surgery for discectomy: A systematic review and meta-analysis of current global clinical trials","volume":"19","author":"Li","year":"2016","journal-title":"Pain Physician"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1016\/j.ijsu.2016.05.061","article-title":"Comparison of percutaneous endoscopic lumbar discectomy versus open lumbar microdiscectomy for lumbar disc herniation: A meta-analysis","volume":"31","author":"Ruan","year":"2016","journal-title":"Int. J. Surg."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"574","DOI":"10.1007\/s00132-018-3528-5","article-title":"Meta-analysis of percutaneous transforaminal endoscopic discectomy vs. fenestration discectomy in the treatment of lumbar disc herniation","volume":"47","author":"Ding","year":"2018","journal-title":"Orthopade"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1186\/s13018-018-0868-0","article-title":"Transforaminal endoscopic discectomy versus conventional microdiscectomy for lumbar discherniation: A systematic review and meta-analysis","volume":"13","author":"Zhang","year":"2018","journal-title":"J. Orthop. Surg. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"802","DOI":"10.3171\/2019.6.SPINE19532","article-title":"Outcomes of endoscopic discectomy compared with open microdiscectomy and tubular microdiscectomy for lumbar disc herniations: A meta-analysis","volume":"31","author":"Barber","year":"2019","journal-title":"J. Neurosurg. Spine"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"538","DOI":"10.1097\/BRS.0000000000003843","article-title":"Percutaneous transforaminal endoscopic discectomy versus open microdiscectomy for lumbar disc herniation: A systematic review and meta-analysis","volume":"46","author":"Gadjradj","year":"2021","journal-title":"Spine"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1012","DOI":"10.1177\/21925682211020696","article-title":"Comparison of endoscopic discectomy versus non-endoscopic discectomy for symptomatic lumbar disc herniation: A systematic review and meta-analysis","volume":"12","author":"Li","year":"2022","journal-title":"Glob. Spine J."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Ahn, Y., and Park, H.B. (2023). Transforaminal endoscopic lumbar foraminotomy for juxta-fusional foraminal stenosis. J. Clin. Med., 12.","DOI":"10.3390\/jcm12175745"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1095","DOI":"10.2214\/AJR.09.2772","article-title":"A practical MRI grading system for lumbar foraminal stenosis","volume":"194","author":"Lee","year":"2010","journal-title":"AJR Am. J. Roentgenol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"E123","DOI":"10.1097\/01.brs.0000157172.00635.3a","article-title":"Validation of the Korean version of the oswestry disability index","volume":"30","author":"Kim","year":"2005","journal-title":"Spine"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"722","DOI":"10.1097\/00007632-200204010-00009","article-title":"Posterolateral endoscopic excision for lumbar disc herniation: Surgical technique, outcome, and complications in 307 consecutive cases","volume":"27","author":"Yeung","year":"2002","journal-title":"Spine"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1155\/2013\/742468","article-title":"What constitutes a clinically important pain reduction in patients after third molar surgery?","volume":"18","author":"Martin","year":"2013","journal-title":"Pain Res. Manag."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1007\/s00586-006-0078-z","article-title":"The effect of duration of symptoms on standard outcome measures in the surgical treatment of spinal stenosis","volume":"16","author":"Ng","year":"2007","journal-title":"Eur. Spine J."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1097\/BRS.0b013e31815e3a10","article-title":"Interpreting change scores for pain and functional status in low back pain: Towards international consensus regarding minimal important change","volume":"33","author":"Ostelo","year":"2008","journal-title":"Spine"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1227\/NEU.0000000000000361","article-title":"Percutaneous endoscopic lumbar foraminotomy: An advanced surgical technique and clinical outcomes","volume":"75","author":"Ahn","year":"2014","journal-title":"Neurosurgery"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"179","DOI":"10.36076\/ppj\/2015.18.179","article-title":"Transforaminal endoscopic treatment of lumbar radiculopathy after instrumented lumbar spine fusion","volume":"18","author":"Telfeian","year":"2015","journal-title":"Pain Physician"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1055\/s-0031-1287774","article-title":"Prevention of development of postoperative dysesthesia in transforaminal percutaneous endoscopic lumbar discectomy for intracanalicular lumbar disc herniation: Floating retraction technique","volume":"54","author":"Cho","year":"2011","journal-title":"Minim. Invasive Neurosurg."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"S51","DOI":"10.1227\/neu.0000000000003337","article-title":"Transforaminal full-endoscopic surgery for lumbar foraminal pathologies: A comparative clinical effectiveness study","volume":"96","author":"Sugiura","year":"2025","journal-title":"Neurosurgery"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1906","DOI":"10.1097\/BRS.0b013e3181fdb4db","article-title":"Polyethylene glycol hydrogel spinal sealant (DuraSeal Spinal Sealant) as an adjunct to sutured dural repair in the spine: Results of a prospective, multicenter, randomized controlled study","volume":"36","author":"Kim","year":"2011","journal-title":"Spine"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1586\/17434440.2014.940314","article-title":"Percutaneous endoscopic decompression for lumbar spinal stenosis","volume":"11","author":"Ahn","year":"2014","journal-title":"Expert Rev. Med. Devices"}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/14\/18\/6446\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:44:48Z","timestamp":1760035488000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/14\/18\/6446"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,12]]},"references-count":38,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2025,9]]}},"alternative-id":["jcm14186446"],"URL":"https:\/\/doi.org\/10.3390\/jcm14186446","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,9,12]]}}}