Interlaminar and transforaminal endoscopic lumbar discectomy: analyzing the selection of surgical approach in 426...

Interlaminar endoscopic lumbar discectomy (IELD) and transforaminal endoscopic lumbar discectomy (TELD) are highly effective treatment options for patients with lumbar disc herniation, but the surgical decision-making process for choosing between these two approaches has not been well described. In this study, authors investigated indications for selecting between IELD and TELD.

In this retrospective review of medical charts at one institution, authors identified a consecutive series of 1-level IELD and TELD procedures performed by a single surgeon. Patients with an age ≥ 18 years who underwent these procedures between January 2019 and January 2025 were eligible for inclusion. Demographic, herniation, surgical, and outcome data were collected. Differences in patient outcomes between pre- and postoperative time points were assessed for both surgical groups using paired Wilcoxon signed-rank tests. Differences in patients who underwent IELD versus TELD were analyzed using t-tests for continuous data and chi-square tests for categorical data. A multivariate logistic regression model was used on a propensity score-matched sample to evaluate the variables associated with undergoing IELD versus TELD when the surgery was performed at L4-5 and above.

A total of 438 single-level procedures were performed in 426 patients. In comparison with patients who underwent IELD, those treated with TELD had a greater mean age (p < 0.001), higher mean BMI (p = 0.016), and higher American Society of Anesthesiologists class (p < 0.001). Patient-reported outcome measures significantly improved after either surgical intervention. IELD was typically performed at L5-S1 (86.3% of IELD procedures), whereas TELD was most often utilized at levels L4-5 and above (95.6% of TELD procedures; p < 0.001). Approach selection differed by herniation location (p < 0.001). Disc herniations in the IELD group were mostly located within the canal (95.3% of IELD procedures), whereas disc herniations in the TELD group were more equally divided between locations within (40.0% of TELD procedures) and outside (46.3% of TELD procedures) the canal. Compared with patients in the TELD group, those treated with IELD at L4-5 and above had significantly higher odds of disc herniation within the canal (OR 19.69, 95% CI 3.61-213.07, p = 0.003), a cranially migrated herniated disc (OR 17.82, 95% CI 3.83-133.65, p = 0.001), and presence of dorsal stenosis (OR 5.15, 95% CI 1.46-20.82, p = 0.014).

This analysis of patient selection criteria indicated that IELD is preferred for disc herniations within the canal at L5-S1. The likelihood of utilizing IELD at L4-5 or above significantly increases when the disc herniation is located within the canal or has migrated cranially or when there is concomitant dorsal stenosis.