Endoscopic Approaches to the Cervical Spine

Cervical disc herniation is common and can affect patients of different ages. It can present as a radiculopathy or myelopathy, depending on the pattern of herniation. Cervical radiculopathy commonly presents with pain, paresthesia, and motor weakness. Cervical myelopathy can typically present with gait disturbance, motor weakness, loss of hand dexterity, bowel or bladder dysfunction, and paresthesia. Traditional surgical management includes anterior cervical discectomy and fusion (ACDF) and posterior cervical foraminotomy (PCF). These approaches have been exhaustively studied and validated. ACDF has long been considered the gold standard of cervical disc replacement techniques, but does pose some disadvantages, mainly the need for fusion and the risk of developed adjacent disc disease requiring future additional surgical intervention. With advances in endoscopic techniques and technologies, opportunities for the development of minimally invasive and less disruptive surgical approaches have presented themselves.

Fully endoscopic cervical spine surgery is different from microendoscopic cervical spine surgery in the sense that the tubular retractor is so small that, even with loupes or a microscope, the operative field is not visible. Fully endoscopic spine surgery is typically cervical spine surgery performed through a working-channel endoscope. Biportal fully endoscopic spine surgery, as the name implies, uses two ports: a port for surgical instruments and a port for an endoscopic camera. Endoscopic approaches to the cervical spine have been reported in the literature and found to be safe and effective.

Here we present four distinct fully endoscopic cervical spine surgery approaches for the treatment of cervical radiculopathy and myelopathy that use a working-channel endoscope, are truly minimally invasive, and do not require a fusion: (1) posterior cervical unilateral laminectomy and bilateral decompression (PCULBD), (2) PCF, (3) anterior endoscopic cervical discectomy (AECD), and (4) anterior cervical transcorporal discectomy (ACTD).

Posterior Cervical Unilateral Laminectomy for Bilateral Decompression

Indications

The indications for PCULBD are single-level and multilevel cervical stenosis. Patients treated typically have significant compression of the spinal cord from buckling of the posterior ligamentum flavum and present with myelopathy. Contraindications are cervical instability or fracture.

Surgical Technique

The procedure is performed under general anesthesia; the patient is positioned prone on hip and chest bolsters with the head secured in the Mayfield head holder. Somatosensory-evoked potential monitoring is typically used. The Joimax iLESSYS® Delta endoscopic system is used for the procedure. A 1-cm incision is made through the skin 1 cm lateral to the midline. Using intermittent fluoroscopic guidance, alternating between lateral and anteroposterior (AP) view, sequential dilators and then a final 10-mm beveled tubular retractor are placed on the junction of the spinous process and the lamina. The 10-mm outer diameter working-channel endoscope with a 6-mm working channel is then placed, and a high-speed Shrill® drill is used to complete the subspinous process laminectomy. An endoscopic micro Kerrison rongeur is used to remove the ligamentum flavum and to finish the laminectomy/laminotomy. Fig. 128.1 demonstrates preoperative and postoperative magnetic resonance images, intraoperative fluoroscopic images, and endoscopic camera views of a multilevel posterior cervical unilateral laminectomy for bilateral decompression.