Circumferential Transforaminal Endoscopic Lumbar Foraminotomy for 360° Exiting Nerve Root Decompression in Patients with Lumbar Foraminal Stenosis.

Lumbar foraminal stenosis is a common cause of intractable radiculopathy that may require surgical treatment when conservative management is ineffective. Transforaminal endoscopic lumbar foraminotomy (TELF) has been developed as a minimally invasive alternative to conventional open surgery, offering reduced tissue disruption and faster recovery. However, conventional TELF techniques may provide limited decompression in complex cases involving severe bony stenosis, fibrosis, or postoperative anatomical changes. This protocol describes circumferential TELF (C-TELF), an advanced endoscopic decompression technique designed to achieve 360° decompression of the exiting nerve root (ENR) in patients with lumbar foraminal stenosis. The goal of this protocol is to provide a reproducible, step-by-step method for achieving circumferential neural decompression through a landmark-based transforaminal approach. The technique incorporates sequential bony unroofing, soft-tissue removal, and complete neural mobilization within the foraminal zone. The procedure is performed using a percutaneous transforaminal approach under fluoroscopic guidance and endoscopic visualization. Decompression is conducted sequentially from the lower pedicle to the upper pedicle to enlarge the neural foramen and establish an adequate safety margin around the ENR. By achieving circumferential decompression, this technique aims to minimize residual neural compression and facilitate durable decompression. This protocol provides detailed procedural guidance to support the safe and reproducible implementation of C-TELF, particularly in patients with complex or refractory lumbar foraminal stenosis.