Unilateral Biportal Endoscopy for Lumbar Spinal Stenosis and Lumbar Disc Herniation

Background: . Description: . Further details regarding irrigation pressure are provided in "Important Tips." The use of a standard powered burr is typical to help osseous decompression, and Kerrison ronguers, pituitaries, osteotomes, and probes utilized in open or tubular cases suffice. Two incisions are made approximately 1 cm lateral to the midline. If working from the left side for a right-handed surgeon, the working portal is typically made at the lower laminar margin of the target level. The camera portal is then made typically 2 to 3 cm cephalad. A lateral radiograph is then utilized to confirm the portal placements. From the right side, the working portal is cephalad and the camera portal is caudal. Because of the switch, the portals may be shifted more distally.The first step is creating a working space because there is no true joint space in the spine. With use of radiofrequency ablation, a working space is created in the interlaminar space. Next, with use of a powered burr or a chiseled osteotomy, the base of the cephalad spinous process is thinned until the insertion of the ligamentum flavum is found. Next, the ipsilateral and contralateral laminae are thinned in a similar fashion. Once the osseous elements are removed, the ligamentum flavum is removed en bloc. The traversing nerve roots are checked under direct high-magnification visualization to ensure that they are decompressed. If a discectomy is necessary, standard nerve-root retractors can be utilized to retract the neural elements. With use of a blunt-tip elevator, the anular defect can be incised and the herniated disc can be removed under direct high-power visualization. In addition, a small curet can be utilized to create a defect in the weakened anulus or membrane covering the extruded disc material in order to help deliver the herniated disc material. Epidural veins are coagulated typically with use of a fine-point bipolar radiofrequency device. Alternatives: Nonoperative treatments include oral anti-inflammatory drugs, physical therapy, and epidural injections; if these fail, alternative surgical treatments include open lumbar laminectomy and/or discectomy, tubular lumbar laminectomy and/or discectomy, and other minimally invasive techniques, such as microendoscopy, uniportal endoscopy, and microscopy-assisted decompression. Rationale: .Furthermore, the use of an endoscope in the biportal technique allows ultra-high magnification of the spinal pathology, decreased capital costs, and the ability to use 2 hands with freedom of movement. UBE provides clear visualization of the neural elements while keeping maximal ergonomic efficiency with the surgeon's head looking straight forward, the shoulders relaxed, and the elbows bent to 90°. Continuous irrigation through the endoscope also helps with bleeding and decreasing the risk of infection. Expected Outcomes: . Important Tips: . Additionally, if the intertransverse membrane or the lateral margins of the disc are violated, hydroperitoneum can occur unknowingly due to the high-pressure system.Gravity or pump pressure of >40 mm Hg may elevate epidural pressure and mask operative bleeding. When the pump is turned off at the end of the surgical procedure, a postoperative epidural hematoma may occur because the bleeding source may not have been recognized while the pump pressure was on.Excessive pump pressure may lead to an increase in intracranial pressure, causing headache or delayed recovery from general anesthesia with stiff posture and hyperventilation.Make sure fluid is emerging from the working portal and the muscle area is not swelling to prevent soft-tissue fluid extravasation.Epidural veins are coagulated typically with a fine-point bipolar radiofrequency device.Osseous bleeding can be controlled with bone wax or a high-speed burr. Acronyms and Abbreviations: MRI = magnetic resonance imagingRF = radiofrequencyAP = anteroposterior.