Traditionally, for patients with a herniated nucleus pulposus (HNP, "hernia") requiring surgical intervention, a sequestrectomy (removal of the hernia) with or without (limited) microdiscectomy (removal of part of the disc) was performed. This was done through an open approach. Over the years, various techniques have emerged and evolved from this procedure. Initially, these were minimally invasive techniques (minimally invasive discectomy), where the hernia was operated on through a small working channel. Later, endoscopic techniques for hernia removal were developed (e.g., PTED).

Currently, it is unclear what the position of endoscopic techniques is within the Dutch guidelines compared to the current standard. Therefore, the question arises whether endoscopic surgery is better or leads to the same results compared to the classic open approach, and what the place of endoscopic techniques should be in the guidelines.

For the comparison of endoscopic interventions with open interventions, we refer to the document titled: “Standpunt Percutane transforaminale endoscopische discectomie (PTED) bij een lumbale hernia nuclei pulposi en radiculaire beenpijn” from the National health Care institute (Zorginstituut Nederland, 2019). The National Health Care institute compared endoscopic interventions with open intervention in adults suffering from lumbal hernia nuclei pulposi (HNP). The conclusion was that endoscopic interventions are non-inferior to open interventions concerning the crucial outcome measures of leg pain and functioning in individuals experiencing persisting leg pain after 10 to 12 weeks of hernia, both in the short- and long term. 

The National Health Care institute determined a difference of 10% on continuous scales (ODI, VAS) and an RR of 1.25 as MCID. The results are depicted in the summary of findings-tables of this chapter.

Results

For the comparison of endoscopic interventions with open interventions, we refer to the document titled: “Standpunt Percutane transforaminale endoscopische discectomie (PTED) bij een lumbale hernia nuclei pulposi en radiculaire beenpijn” from the National Health Care institute (Zorginstituut Nederland, 2019).

A systematic review of the literature was performed to answer the following question:

What are the positive and negative effects of various endoscopic techniques for operating on an HNP compared to open interventions?

Table 1. PICO

Relevant outcome measures

The guideline panel considered leg pain, functioning (including ADL, work, and social functioning) as critical outcome measures for decision making; and opioid use, back-pain, (procedure-related) complications (within 30 days and recurrences) as important outcome measures for decision making.

A priori, the guideline panel did not define the outcome measures listed above but used the definitions used in the studies.

For determining the Minimal Clinically Important Difference (MCID), we utilized the article by Ostelo (2008), which considers a 20% to 30% improvement from the baseline measurement as a minimally clinically relevant difference (within-group change). This roughly corresponds to the values in table 3. The working group applies the same values as clinically relevant differences between groups (between-group change). Statements regarding the clinical relevance of a difference are made only if a statistically significant difference is found in an outcome measure. This was considered best estimate at the moment of this guideline development.

Table 2. Minimal Important difference (MCID) for outcomes

Search and select (Methods)

The databases Medline (via OVID) and Embase (via Embase.com) were searched with relevant search terms until January 26^th, 2024. The detailed search strategy is available upon request. The systematic literature search resulted in 606 hits. Studies were selected based on the following criteria:

• Systematic reviews (searched in at least two databases, detailed search strategy, risk of bias assessment and results of individual studies available), or randomized controlled trials (RCTs).
• Studies including twenty or more participants (³ ten per arm).
• Studies with a minimum follow-up of 6 weeks.
• Studies according to PICO 1 or PICO 2 and
• Studies with English language full-text publication.

Initially, 39 studies were selected based on title and abstract screening. After reading the full text, 38 studies were excluded (see the exclusion table under the tab ‘Evidence tabellen’).

One systematic review (Gadjradj, 2019) was a match with PICO 1. This systematic review has already been evaluated using the same methodology (GRADE) which is being used in this guideline. For the comparison of endoscopic interventions with open interventions, we refer to the document titled: “Standpunt Percutane transforaminale endoscopische discectomie (PTED) bij een lumbale hernia nuclei pulposi en radiculaire beenpijn” from the National Health Care institute (Zorginstituut Nederland, 2019).

1. Chen Z, Wang X, Cui X, Zhang G, Xu J, Lian X. Transforaminal Versus Interlaminar Approach of Full-Endoscopic Lumbar Discectomy Under Local Anesthesia for L5/S1 Disc Herniation: A Randomized Controlled Trial. Pain Physician. 2022 Nov;25(8):E1191-E1198. PMID: 36375189.
2. Mo X, Shen J, Jiang W, Zhang X, Zhou N, Wang Y, Hu Z, Hao J. Percutaneous Endoscopic Lumbar Diskectomy for Axillar Herniation at L5-S1 via the Transforaminal Approach Versus the Interlaminar Approach: A Prospective Clinical Trial. World Neurosurg. 2019 May;125:e508-e514. doi: 10.1016/j.wneu.2019.01.114. Epub 2019 Jan 31. PMID: 30710722.
3. Nederlandse vereniging voor Neurochirurgie (NVvN) en Nederlandse Orthopaedische Vereniging (NOV). PTED- Uw verzoek tot opstellen waarborgen document en reactie op uw brief van 8 september 2021. 2021. Beschikbaar via: https://www.zorginstituutnederland.nl/binaries/zinl/documenten/brief/2021/12/16/brief-nvvv-en-nov-over-pted/Brief+NVvV+en+NOV+aan+Zorginstituut+Nederland+over+leidraad+en+voorwaarden+introductie+PTED-operatie.pdf.
4. Nie H, Zeng J, Song Y, Chen G, Wang X, Li Z, Jiang H, Kong Q. Percutaneous Endoscopic Lumbar Discectomy for L5-S1 Disc Herniation Via an Interlaminar Approach Versus a Transforaminal Approach: A Prospective Randomized Controlled Study With 2-Year Follow Up. Spine (Phila Pa 1976). 2016 Oct;41 Suppl 19:B30-B37. doi: 10.1097/BRS.0000000000001810. PMID: 27454540.
5. Orde van Medisch Specialisten. Leidraad NIKP: Nieuwe interventies in de Klinische praktijk. Kennisinsituut van Medisch Specialisten. 2014. Beschikbaar via: https://demedischspecialist.nl/sites/default/files/Leidraad%20Nieuwe%20interventies%20in%20de%20klinische%20praktijk%20def.pdf.
6. Zhang ZH, Du Q, Wu FJ, Liao WB. Optimal approach for total endoscopic discectomy and its effect on lumbar and leg function in patients with disc herniation. World J Clin Cases. 2022 Dec 16;10(35):12928-12935. doi: 10.12998/wjcc.v10.i35.12928. PMID: 36569011; PMCID: PMC9782947.
7. Zorginstituut Nederland. Standpunt Percutane transforaminale endoscopische discectomie (PTED) bij een lumbale hernia nuclei pulposi en radiculaire beenpijn. 2020. Beschikbaar via: https://www.zorginstituutnederland.nl/binaries/zinl/documenten/standpunten/2020/11/30/standpunt-pted-bij-lage-rughernia-en-uitstralende-beenpijn/Brief+MZS+met+standpunt+PTED+bij+een+lumbale+hernia+nuclei+pulposi+en+radiculaire+beenpijn.pdf.