Endoscopic spine surgery has rapidly evolved as a minimally invasive technique for treating various spinal pathologies. However, its use in removing epidural metastatic tumors remains insufficiently explored. This video article presents 2 cases utilizing unilateral biportal endoscopic spine surgery for resection of epidural metastatic tumors causing spinal cord compression. The first case involved a 63-year-old woman with metastatic non-small cell lung cancer at T4–5, and the second case an 86-year-old man with prostate cancer metastases at T6–9. Both patients presented with motor weakness (American Spinal Injury Association [ASIA] grade C) and potential spinal instability (SINS [Spinal Instability Neoplastic Scale] score 7). The surgical techniques emphasized precise identification and dissection of the tumor–dura interface to minimize dural injury and bleeding—an essential consideration when managing vascular lesions, particularly under antiplatelet therapy. Both cases achieved complete tumor resection with minimal blood loss (60–90 mL) and operative times of 71 and 109 minutes, respectively. Postoperatively, both patients improved to ASIA grade D and began early radiotherapy, underscoring the advantages of this minimally invasive approach in enabling prompt adjuvant treatment. Endoscopic epidural tumor removal represents a safe and less invasive alternative to open surgery for selected patients, though further long-term evaluation is warranted.

Chiari malformation, when accompanied by progressive neurological symptoms or syringomyelia, often necessitates surgical decompression. Although endoscopic spinal surgery continues to advance, its application in foramen magnum decompression remains limited. This video article demonstrates the biportal endoscopic foramen magnum decompression technique for Chiari type I malformation. We present the case of a 19-year-old female patient with progressive headache, motor weakness, and radiological evidence of 7-mm tonsillar descent with C2–7 syringomyelia. She successfully underwent biportal endoscopic foramen magnum decompression with C1 laminectomy. The procedure employed a triportal approach with safe docking on the C2 spinous process, allowing a minimally invasive C1 laminectomy and foramen magnum decompression extended to the suboccipital area. Postoperatively, computed tomography confirmed adequate decompression, and magnetic resonance imaging revealed expansion of the posterior fossa with resolution of tonsillar herniation. The patient experienced no complications or symptom recurrence at the 3-month follow-up. Despite a minor intraoperative–postoperative measurement discrepancy, which highlights the anatomical considerations required to achieve sufficient decompression, this video supports the feasibility of biportal endoscopic surgery. This approach may provide comparable clinical outcomes to conventional open surgery while offering minimally invasive advantages, though long-term follow-up remains essential.

Endoscopic spine surgery (ESS) provides minimally invasive treatment options for a wide range of degenerative spinal disorders. However, performing a safe decompressive laminectomy, which is an essential and foundational step in ESS, can be challenging for novice surgeons, especially due to the risk of iatrogenic dural injury during flavectomy. This video article introduces the “crescent osteotomy” technique, which employs a mallet and chisel for controlled, anatomically precise resection of the ligamentum flavum. Although this approach has been adopted by some surgeons, it offers a straightforward and safe method that allows for effective additional laminectomy while facilitating easier flavectomy. The technique intentionally preserves the ligamentum flavum as a protective layer during the critical decompression phase. By doing so, the method reduces the likelihood of accidental dural tears and prevents unnecessary facet violation, making it particularly advantageous for beginning ESS surgeons. A representative case involving an 85-year-old man with L4–5 central stenosis and gait disturbance illustrates its effectiveness, with excellent postoperative neurological recovery and pain relief. The crescent osteotomy technique thus represents a feasible, efficient, and safe surgical option that enhances intraoperative control and optimizes clinical outcomes in ESS.

Unilateral biportal endoscopy offers substantial advantages in spinal surgery but continues to carry a risk of neural injury due to the difficulty of distinguishing neural structures from surrounding tissues. This video article demonstrates the intraoperative use of indigo carmine to mitigate this risk. Indigo carmine selectively stains fibrous tissue and disc material while sparing nerve roots, owing to its impermeability to intact cellular membranes. This property enhances visual differentiation and promotes surgical safety. We present 2 cases involving 64-year-old female patients who underwent discectomy for ruptured L5–S1 discs. In both cases, intraoperative injection of indigo carmine into the working field or disc space effectively delineated neural elements from adhesive tissues and disc material. Postoperative imaging confirmed successful decompression. Indigo carmine represents a useful, surgeon-friendly, cost-effective, and time-efficient adjunct that improves visualization and helps prevent iatrogenic neural injury. Its use is particularly recommended for revision surgery, complex degenerative conditions, and for endoscopic spine surgeons in training.

OBJECTIVE: To analyze the clinical characteristics between neurogenic and non-neurogenic cause of vocal cord immobility (VCI). METHODS: The researchers retrospectively reviewed clinical data of patients who underwent laryngeal electromyography (LEMG). LEMG was performed in the bilateral cricothyroid and thyroarytenoid muscles. A total of 137 patients were enrolled from 2011 to 2016, and they were assigned to either the neurogenic or non-neurogenic VCI group, according to the LEMG results. The clinical characteristics were compared between the two groups and a subgroup analysis was done in the neurogenic group. RESULTS: Among the 137 subjects, 94 patients had nerve injury. There were no differences between the neurogenic and non-neurogenic group in terms of demographic data, underlying disease except cancer, and premorbid events. In general characteristics, cancer was significantly higher in the neurogenic group than non-neurogenic group (p=0.001). In the clinical findings, the impaired high pitched ‘e’ sound and aspiration symptoms were significantly higher in neurogenic group (p=0.039 for impaired high pitched ‘e’ sound; p=0.021 for aspiration symptoms), and sore throat was more common in the non-neurogenic group (p=0.014). In the subgroup analysis of neurogenic group, hoarseness was more common in recurrent laryngeal neuropathy group than superior laryngeal neuropathy group (p=0.018). CONCLUSION: In patients with suspected vocal cord palsy, impaired high pitched ‘e’ sound and aspiration symptoms were more common in group with neurogenic cause of VCI. Hoarseness was more frequent in subjects with recurrent laryngeal neuropathy. Thorough clinical evaluation and LEMG are important to differentiate underlying cause of VCI.
Electromyography ; Hoarseness ; Humans ; Laryngeal Muscles ; Laryngeal Nerves ; Pharyngitis ; Recurrent Laryngeal Nerve ; Retrospective Studies ; Vocal Cord Paralysis ; Vocal Cords*