Percutaneous Transforaminal Endoscopic Discectomy: Surgical Techniques, Indications, and Outcomes.

Background: Percutaneous transforaminal endoscopic discectomy (PTED) is a minimally invasive technique for the treatment of symptomatic lumbar disc herniation (LDH) that is growing in popularity. The procedure involves the insertion of a transforaminal spinal endoscope for direct access and removal of intra and extra-foraminal disc fragments Description: The patient is preferably placed in a prone position. A spinal needle is advanced under fluoroscopic guidance into the foramen to the medial border of the inferior pedicle. A guidewire is introduced through the needle cannula, and sequential dilators are advanced into the foramen. A partial facetectomy/foraminotomy is performed so that a 10-mm working cannula and spinal endoscope can be introduced. Endoscopic pituitary rongeurs are utilized to remove the extruded disc material. Once the extruded fragments are no longer visualized, a probe is utilized to verify that no remaining disc material is present, and a diagnostic endoscopy is performed. The cannula is removed, and the incision is closed in a standard fashion. Alternatives: Nonoperative alternatives to PTED include activity modification, nonsteroidal anti-inflammatory drugs and/or acetaminophen, physical therapy, and epidural steroid injections Rationale: PTED shares similar indications as open and tubular discectomy, including soft LDH confirmed on imaging, persistent radiculopathy, new sensory/motor neurologic deficits, and failed nonoperative treatment of >6 weeks Expected Outcomes: PTED is a safe procedure that has been shown to improve patient-reported outcomes and functional status. In a recent meta-analysis, Gadjradj et al. reported a pooled complication rate of 4.6% (range, 0% to 8.6%) for PTED Important Tips: The exiting nerve root is at risk during the approach. The foramen is entered at the furthest point from the nerve root by targeting the superior-most portion of the inferior pedicle (anteroposterior view) and the posterior-inferior corner of the disc (lateral view).For procedures performed with the patient under awake anesthesia, the patient should be monitored for nerve-root injury by asking them to report pain and move their feet. When a patient is fully anesthetized, neuromonitoring should be utilized. Neuromonitoring is especially important to remove fragments in difficult-to-access locations.Because of the narrow corridor, it may be difficult to confirm full decompression. Thoroughly reviewing the patient imaging to understand the fragment location is necessary. Postoperatively, it is important to evaluate patients to identify cases of incomplete decompression.The dorsal root ganglion is sensitive to irritation. Prior to closure, we irrigate the working cannula with a steroidal solution.The learning curve for PTED has been shown to be 31 cases, which is longer than traditional microdiscectomy techniques Acronyms and Abbreviations: PTED = percutaneous transforaminal endoscopic discectomyLDH = lumbar disc herniationAP = anteroposteriorPSH = past surgical historyMRI = magnetic resonance imagingOR = operating roomPACU = post-anesthesia care unit.