Clinical Results and Review of Techniques of Thoracic Endoscopic Unilateral Laminotomy with Bilateral Decompression (TE-ULBD) Using the Outside-In Technique for Thoracic Ossified Ligamentum Flavum

Abstract

Objective Uniportal full endoscopic thoracic endoscopic surgery can be performed through transforaminal and interlaminar approaches. The interlaminar approach is commonly described as thoracic endoscopic unilateral laminotomy for bilateral decompression (TE-ULBD), which is typically indicated for pathologies such as ossified ligamentum flavum and other posteriorly based compressive pathologies. TE-ULBD decompresses the central and lateral recesses of the thoracic spinal canal. Both the outside-in (over the top of ligamentum flavum) and inside-out (under the ligamentum flavum) approaches can decompress the thoracic spinal canal through the uniportal interlaminar endoscopic route. Methods A retrospective clinical cohort evaluation of patients who underwent TE-ULBD was performed from January 2018 to December 2021 Results A cohort of 50 cases of TE-ULBD with a mean age of 65 years old were evaluated. The complication rate was 5.4% and the reoperation rate was 2%. Statistically significant mean VAS improvements were found at 1 week, 6 months, and the final follow-up, with changes of 3.95±1.49, 4.95±1.7, and 5.2±1.8 points, respectively. Likewise, the mean Oswestry Disability Index improvements at 1 week, 3 months, and the final follow-up were 33.8±9.05, 40.12±10.38, and 41.92±11.26, respectively (p<0.001). Significant improvements were found in the cross-sectional area of the spinal canal in the upper endplate, mid-disc, and lower endplate (57.62±50.6, 89.86±55.93, and 64.93±60.91 mm2, respectively; p<0.001). Conclusion TE-ULBD using the outside-in technique could achieve good clinical outcomes and a low rate of complications in our cohort of patients.

Keywords

• spinal stenosis
• endoscopic spine surgery
• minimally invasive spine surgery
• thoracic spine
• ligamentum flavum
• omit foraminal ligament