Minimally invasive and simultaneous removal of herniated intracanal and extracanal lumbar nucleus pulposus with a percutaneous spinal endoscope.

Herniated nucleus pulposus (HNP) in the lumbar spine is usually found in the neural canal (in the intracanal space) and occasionally in the extracanal space, where it is known as a lateral HNP. HNP is rarely found simultaneously in both spaces. However, we experienced such a case in a 48-year-old man who presented with right leg pain and lower back pain that had lasted for more than a year. MRI revealed HNP in both the right intracanal and extracanal spaces at L2-L3. A transforaminal approach was used to complete a percutaneous endoscopic discectomy. An 8-mm incision was made with the patient under local anesthesia, and the percutaneous endoscope was inserted at the affected disc space. First, the HNP fragments in the intracanal space were removed, and then the cannula and endoscope were extracted to the extracanal space where the extracanal fragments were removed. Two hours after the surgery, the patient stood and walked. Right leg pain and lower back pain had disappeared. Unlike other techniques such as Love's procedure and the microendoscopic discectomy technique, the use of a transforaminal approach with the percutaneous endoscopic technique enables the HNP fragments in the intracanal and extracanal spaces to be removed at the same time with a single approach.