Unilateral biportal endoscopic surgery for intradural lumbar disc herniation: illustrative case.

backgroundThe authors successfully removed a type B intradural lumbar disc herniation (IDH) using unilateral biportal endoscopic (UBE) technology, without CSF leakage, even though the nerve root sheath was not sutured. This emphasizes the diagnostic and therapeutic role of UBE technology in managing type B IDH. OBSERVATIONS: An 82-year-old male patient with multilevel lumbar disc herniation underwent endoscopic discectomy and lumbar laminoplasty at the symptomatic level using UBE technology. During surgery, under endoscopic visualization, a white, mass-like protrusion was observed on the surface of the responsible nerve root, consistent with type B IDH. The nerve root sheath was incised, and the herniated nucleus pulposus was successfully removed without CSF leakage. The nerve root sheath was left open without repair. LESSONS: Using UBE technology to treat lumbar disc herniation, if an abnormal bulge or white, mass-like protrusion is observed on the nerve root under endoscopic visualization, clinicians should highly suspect the presence of type B IDH. In such cases, the nerve root sheath can be incised along the direction of the nerve root to safely remove the herniated disc material. Notably, repair of the nerve root sheath is not required, and no CSF leakage occurred in this case. https://thejns.org/doi/10.3171/CASE25795.