Microscopic tubular unilateral laminotomy for bilateral decompression: a detailed surgical illustration and single-arm cohort study on outcomes in lumbar canal stenosis.

BACKGROUND

Microscopic tubular unilateral laminotomy for bilateral decompression (MT-ULBD) is a minimally invasive technique for lumbar spinal stenosis (LSS) that aims to achieve adequate neural decompression while minimizing tissue disruption. This study evaluates its clinical and radiological outcomes and documents key surgical steps through detailed illustrations.

METHODS

This single-center, single-arm cohort study was conducted at Amala Institute of Medical Sciences between September 2024 and April 2025 (IRB No. 34/EC/24/AIMS-16). Patients aged 20-60 years with LSS unresponsive to at least 6 months of conservative therapy were included after obtaining informed consent. Outcomes included pain relief (VAS), functional improvement (ODI), and radiological decompression (canal diameter). Operative parameters, hospital stay, and complications were recorded. Statistical analysis was performed using SPSS version 29.0 (IBM Corp., Armonk, NY); P < 0.05 was considered significant.

RESULTS

Of 44 enrolled patients, 41 completed follow-up (28 females, 13 males; mean age 48.6 ± 8.3 years). Mean VAS scores improved from 7.0 ± 1.2 to 2.0 ± 1.1 (P < 0.001), and ODI from 52.4 ± 8.6 to 22.3 ± 6.1 (P < 0.001). Mean canal diameter increased from 10.8 ± 1.2 to 14.8 ± 1.4 mm (P < 0.001). Mean operative time was 26.3 ± 6.4 min, blood loss 7.5 ± 6.8 mL, and hospital stay 4.0 ± 1.1 days. Two patients (4.9%) had small dural tears successfully repaired with 6-0 Prolene; three (7.3%) developed superficial infections managed conservatively. No neurological deficits or postoperative instability were observed.

CONCLUSIONS

MT-ULBD provides significant clinical and radiological improvement with minimal morbidity, making it an effective and safe minimally invasive alternative for the treatment of LSS. Surgical illustrations aid in the understanding and reproducibility of the technique.