The Endoscopic Trans-Superior Articular Process Approach: A Novel Minimally Invasive Surgical Corridor to the Lateral Recess

Abstract BACKGROUND Transforaminal approaches to the lumbar spine are typically performed utilizing Kambin's triangle as approach corridor; however, degenerative changes can distort anatomy and expose the exiting nerve root to inadvertent injury. OBJECTIVE To describe the surgical technique of a novel full-endoscopic approach to access the lateral recess and report clinical outcomes. METHODS The trans-superior articular process (SAP) approach involves partial resection of the SAP, allowing access to the lateral recess both ventral and dorsal to the traversing nerve root. A retrospective review of 40 patients who had undergone a trans-SAP approach for decompression of lateral recess pathology was conducted. Outcomes were measured using visual analog scores (VAS) and Oswestry Disability Index (ODI) at 2 wk, 3 mo, and at last follow-up. RESULTS At a mean follow-up of 24 mo, patients experienced statistically significant improvement of the VAS for ipsilateral leg pain, VAS for back pain, and ODI when comparing preoperative values to all postoperative time points. The percentage of patients reaching a minimally clinically important difference for VAS leg pain and ODI was approximately 90% and 88%, respectively. The complication profile was favorable with no dural tears and no postoperative motor or sensory deficits. One patient required revision, with a total reoperation rate of 3%. CONCLUSION The trans-SAP approach is a novel approach that utilizes a safe surgical corridor via the SAP to access lateral recess pathology. Our initial clinical experience suggests that the trans-SAP approach allows for treatment of lateral recess and foraminal pathology with low complication rates.