A Trans-pedicle Approach to Avoid Exiting Nerve Root Injury in Full-Endoscopic Transforaminal Decompression: A Case Report

This report aims to describe a case with an extremely low-located exiting nerve root and introduce the trans-pedicle approach for endoscopic transforaminal decompression, which can enable the safe visualization of the exiting nerve root. We present the medical history, imaging findings, and surgical procedures of a 62-year-old male who underwent left L3/4 and L4/5 endoscopic transforaminal decompression for foraminal stenosis. The patient presented with pain and numbness in the anterior and lateral aspects of the left thigh. MRI revealed left L3/4 and L4/5 foramen stenosis and endoscopic transforaminal decompression was performed. The working channel was guided and positioned at the upper lateral part of the left L4 pedicle. We observed the L3 root being compressed by scar tissues against the upper edge of the L4 pedicle. Then we used a protective diamond burr to drill the upper part of the L4 pedicle, enlarging the L3/4 foramen. Subsequently, pituitary Rongeur, Kerrison, and punches were employed to meticulously remove scar tissues around the exiting root. The same procedure was performed for left L4-5 foramen decompression. The radicular symptoms were relieved immediately after the surgery. Our proposed trans-pedicle endoscopic transforaminal approach can reduce the risk of injuring a low-located exiting nerve root. It can also help standardize the procedure, improves working channel stability, and facilitates the learning process, making it a valuable technique for full-endoscopic transforaminal decompression.