How do outcomes of endoscopic lumbar decompression compare to open decompression in randomized studies?

1. What the randomized evidence actually measures: functional outcomes come out similar

Across randomized controlled trials aggregated in recent meta-analyses, patient-centered functional end points—Oswestry Disability Index (ODI), overall clinical success rates, and long-term pain scores—generally show no consistent, clinically meaningful superiority of full-endoscopic over microscopic/open decompression: pooled RCT data in one meta-analysis returned no statistically significant difference for core functional outcomes after accounting for between-study variability ^{[1] [4]}, and an individual RCT comparing biportal endoscopy to microscopic laminectomy found no significant difference in ODI at 12 months ^[5].

2. Where endoscopy repeatedly shows advantages: perioperative recovery and early pain

Multiple randomized and controlled studies report that endoscopic approaches often reduce intraoperative blood loss, shorten hospitalization, and yield lower early postoperative back-pain scores—effects that appear consistently enough to be highlighted in systematic reviews and meta-analyses (reduced blood loss WMD ≈ −33 mL; shorter LOS ~1–2 days; less early back pain) and in RCTs such as the 2023 full-endoscopic versus tubular-microscopic trial that found less back pain, shorter stays, and lower blood loss for the endoscopic arm ^{[3] [2] [6]}.

3. The safety story is mixed: fewer some complications, unclear overall advantage

Pooled analyses report lower rates of specific complications with endoscopy—examples include fewer incidental durotomies and surgical-site infections in some meta-analyses—yet heterogeneity and the small absolute number of events make generalization risky; one influential meta-analysis concluded full-endoscopic procedures had fewer complications and shorter operative times ^{[4] [3]}, while another pooled RCT analysis emphasized substantial heterogeneity and reported no clear difference in some outcomes after random-effects modeling ^[1]. Large registry and database studies provide complementary but nonrandomized data that show variable early complication and readmission profiles, underscoring that RCT-level safety signals are encouraging but not definitive ^{[7] [8]}.

4. Why conclusions remain provisional: heterogeneity, small trials, and shifting techniques

The randomized literature is constrained by a small number of RCTs, variation across endoscopic techniques (uniportal vs biportal vs full endoscopic vs tubular MIS comparisons), inconsistent follow-up intervals, and methodological heterogeneity that produces high I2 values in meta-analyses—factors explicitly called out by reviewers as threats to credibility and statistical certainty ^{[9] [1]}. Meta-analysts therefore often apply random-effects models and note limited statistical power, while real-world database studies—larger but nonrandomized—report mixed results and raise concerns about selection bias and technology-driven costs not captured by RCTs ^{[1] [10] [11]}.

5. Bottom line and research gaps: equivalent function, early recovery benefits, more RCTs needed

Randomized trials to date support the practical conclusion that endoscopic lumbar decompression is at least noninferior to microscopic/open decompression for functional recovery and may offer consistent advantages in blood loss, early pain, and shorter hospitalization, with some meta-analyses even favoring endoscopy on complication rates—but heterogeneity, limited RCT numbers, and evolving endoscopic platforms mean higher-quality, larger, technique-stratified RCTs with standardized endpoints and cost-effectiveness analyses are still required before declaring an unequivocal superiority ^{[2] [3] [1] [11]}.