Effect of Dorsal Root Ganglion Retraction in Endoscopic Lumbar Decompressive Surgery for Foraminal Pathology: A Retrospective Cohort Study of Interlaminar Contralateral Endoscopic Lumbar Foraminotomy and Discectomy versus Transforaminal Endoscopic Lumbar Foraminotomy and Discectomy.

ABSTRACT

OBJECTIVE: Postoperative dysesthesia (POD) is a common complication in surgery involving foraminal diseases, including lumbar foraminal or extraforaminal herniated nucleus pulposus (HNP). Minimal dorsal root ganglion (DRG) retraction is key to preventing POD. We compared the clinical results, safety, and efficacy between the paraspinal transforaminal approach requiring DRG retraction and the interlaminar contralateral approach without DRG retraction for foraminal and extraforaminal diseases. METHODS: A retrospective cohort study was performed of 50 patients who underwent uniportal transforaminal endoscopic lumbar foraminotomy and discectomy (TELD) and 50 patients who underwent anuniportal interlaminar contralateral endoscopic lumbar foraminotomy and discectomy (ICELF) because of lumbar foraminal HNP. The operated levels, combined degenerative diseases, postoperative complications, and POD were analyzed. The visual analog scale (VAS) pain scores, modified Oswestry Disability Index, and MacNab criteria for evaluating pain disability and response were analyzed. RESULTS: In the ICELF group (total, n = 7, 14%), there were 5 (10%) and 2 (4%) patients with POD grade 1 and 2, respectively. In the TELD group (total, n = 13, 26%), there were 7 (14%), 5 (10%), and 1 (2%) patients with POD grade 1, 2, and 3, respectively. The overall occurrence rate of grade 2 and greater POD was higher in the TELD group (n = 6, 12%) than in the ICELF group (n = 2, 4%). In the ICELF group, 3 of 9 patients (33%) with combined canal structure deforming diseases had POD, of whom none had POD of grade 2 and greater. In the TELD group, 4 of 7 patients (57%) with combined canal structure deforming diseases had POD, of whom all had POD of grade 2 and greater. Two surgical groups showed favorable clinical outcomes with the visual analog scale, Oswestry Disability Index, and MacNab criteria. CONCLUSIONS: Both TELD and ICELF were found to treat foraminal or extraforaminal HNP with good clinical outcomes. ICELF might have a lower POD rate in complicated cases such as adjacent segment disease, degenerative spondylolisthesis, and isthmic spondylolisthesis. This surgical procedure could be an alternative in complicated cases or in patients with an anatomically limited L5-S1 level. However, the procedure is technically challenging to perform.