The Posterior Oblique Lateral (POL) Full-Endoscopic Approach: A Transverse Process Docking Technique to Avoid Early Neural Contact in Challenging Foraminal and Extraforaminal Pathologies - Technical Note and Illustrative Case Series

Endoscopic spine surgery continues to expand in scope. Although the transforaminal route through Kambin triangle remains a key access corridor, its use may be limited by anatomical factors such as disc height loss, spondylolisthesis, nerve root anomalies, or a high iliac crest. This technical note describes a posterior oblique lateral (POL) approach that may facilitate access in anatomically constrained cases. The POL approach begins with docking on the transverse process along a posterior-oblique trajectory. The superior articular process, facet capsule, and pars are then identified stepwise before the working corridor is advanced to Kambin triangle under direct visualization. The technique is designed to create a wider working angle and reduce early contact with neural structures. Its use is demonstrated in 3 patients with foraminal stenosis, spondylolytic spondylolisthesis requiring fusion, and far-out syndrome. The POL approach provided access to the target pathology in all 3 cases, including one case with a markedly narrowed Kambin triangle. Decompression and fusion procedures were completed successfully, including facetectomy, cage placement, and extraforaminal decompression. All patients had symptomatic improvement without perioperative complications. Given the limited sample size, comparative efficacy and safety remain uncertain, but these cases support the technical feasibility of the approach. In anatomically constrained cases, the POL approach may provide a feasible and versatile endoscopic alternative. By establishing a reproducible working corridor, it may complement the standard transforaminal approach.