Anterior transcorporeal approach of percutaneous endoscopic cervical discectomy for disc herniation at the C4–C5 levels: a technical note

Background Context With the continuous development of the spinal endoscopic technique in recent years, percutaneous endoscopic cervical discectomy (PECD) has emerged, which bridges the gap between conservative therapy and traditional surgery and has been mainly divided into the anterior transdiscal approach and the posterior interlaminar access. Because of the relatively greater violation to the anterior nucleus pulposus, there is a higher potential of postoperative intervertebral space decrease in the anterior transdiscal approach than in the posterior interlaminar access. In addition, when the herniated lesion is migrated upward or downward behind the vertebral body, both approaches, and even anterior cervical discectomy and fusion, are impractical, and corpectomy is commonly considered as the only efficacious treatment. Anterior transcorporeal approach under endoscopy could enable an individual and adjustable trajectory within the vertebral body under different conditions of disc herniation preserving the motion of adjacent segment, especially in a migrated or sequestered lesion. Purpose This report aimed to first describe a novel anterior transcorporeal approach under endoscopy in which we addressed a migrated disc herniation at the C4–C5 levels. Study design A technical report was carried out. Patient sample A 37-year-old woman presented with posterior neck pain and weakness of extremities for 9 months. On neurologic examination, tingling sensation and numbness were not obvious. However, the power of extremities was dramatically decreased at a level of 3. Hoffmann sign was positive in the bilateral hand. Magnetic resonance imaging (MRI) showed a huge herniation of the C4–C5 disc compressing the median area of the spinal cord. Besides the C4–C5 disc herniation, preoperative computer tomography (CT) also detected that the herniated disc had partial calcification. A novel anterior transcorporeal approach of PECD, through the vertebral body of C5, was performed to address a migrated disc herniation at the C4–C5 levels. Outcome measures The posterior neck pain was measured using the visual analog scale (VAS). Methods A novel anterior transcorporeal approach under endoscopy was performed to address a migrated disc herniation at the C4–C5 levels. Results This operation was accomplished in 75 minutes. Postoperatively, the drainage tube was retained into the drilling hole for 24 hours to avoid the possibility of hematoma. The patient was advised to wear a neck collar for 3 weeks. Immediately after the operation, the posterior neck pain improved from VAS 7/10 preoperatively to 3/10, and the myodynamia of extremities improved stepwise. At 12 hours postoperatively, the range of motion was also improved. In the further follow-up, the patient has completely recovered from the preoperative symptoms, whose myodynamia of extremities is normal. Besides the postoperative MRI, a total removal of the herniated disc and the transcorporeal drilling tunnel are observed in CT. At postoperative 3-month follow-up, neither disc space narrowing nor instability was observed on CT, in which the bone defect after drilling tunnelwas partially decreased, indicating bone healing. There were no surgery-related complications, such as dysphagia, Horner syndrome, recurrent laryngeal nerve palsy, vagus nerve injury, tracheoesophageal injury, or cervical hematocele. Conclusions As a supplement to the described surgical approach of PECD, the transcorporeal approach is a novel access for the treatment of cervical intervertebral disc herniation. Among the advantages of this approach are providing a clear visual field during microendoscopic surgery and decreasing the intraoperative iatrogenic injury to, as well as avoiding violation to the discal tissue. Theoretically, the potential of secondary decline of intervertebral height is low. However, as the limitation of one case shows, whether this transcorporeal approach is efficacious and reliable should be verified in a further comparative cohort study with a large volume of patients.