Outside-in foraminal access for cervical dumbbell tumors: a surgical paradigm shift with technical insights and clinical outcomes.

Abstract

Cervical dumbbell tumors present surgical challenges due to their proximity to critical structures, including the facet joints and vertebral artery (VA). Conventional posterior approaches often require facet joint resection and fusion, risking spinal instability. This study summarizes the authors' experience with a lateral foraminal approach that preserves facet integrity through a minimally invasive corridor. The lateral foraminal approach begins with an incision along the lateral border of the sternocleidomastoid, proceeding obliquely "outside-in" through the interscalene space between the scalene muscles. Depending on the specific spinal level and corresponding orientation of the intervertebral foramen, this surgical concept incorporates both the anterolateral approach (C2-3 to C7-T1) and the posterolateral approach (C1-2 and occasionally C2-3). The study comprised 30 males and 25 females with a median (range) age of 45 (11-69) years. The tumors were located from C1-2 to C7-T1 intervertebral foramina. Gross-total resection with preserved facet joint integrity was achieved in all cases, with visualization safeguarding brachial plexus and VA integrity during resection. Surgery resulted in significant improvements in neurological function and pain, with mean Japanese Orthopaedic Association (JOA) scores increasing from 13.3 to 15.1 (p < 0.001) and mean visual analog scale (VAS) scores decreasing from 4.3 to 2.4 (p < 0.001). The lateral foraminal approach is a minimally invasive technique for resecting cervical dumbbell tumors via an anatomical corridor. It preserves the facet joint entirely, eliminating the need for internal fixation or fusion. Under direct visualization, the brachial plexus and VA are microsurgically protected throughout dissection.