Posterior Transdural Approach for a Calcified Thoracic Intradural Disc Herniation Using a 3-Dimensional Exoscope: 2-Dimensional Operative Video

This video depicts the removal of an intradural thoracic disc herniation through a purely transdural approach. Thoracic disc herniations are rare, and less than 5% are intradural. Though thoracic disc herniations are removed through a posterolateral or transthoracic corridor, there is literature to support a transdural approach for central herniations.1-3 Although the transdural approach has been selectively adopted for central soft herniations, calcified herniations have been regarded as less suitable.1,2 Intradural thoracic herniations have not been specifically addressed by a transdural approach in the limited literature, though it has been utilized in conjunction with a larger transthoracic approach.4 Our case features a 72-yr-old female presenting with worsening left leg weakness. Computed tomography (CT) identified a multilobulated ventral calcified mass at T11-12. Magnetic resonance imaging was not possible because of an incompatible pacemaker. Our impression was that this likely represented an intradural meningioma though a calcified intradural disc herniation was considered. Given the apparent intradural location, we opted for a transdural approach only via T11-12 laminectomy and a midline dural opening. Dentate ligament sectioning allowed a clear corridor to the now apparent disc material. Postoperative CT confirmed near complete resection, and the patient showed neurological improvement. Ultimately, the transdural approach alone led to complete discectomy while avoiding the morbidity of an invasive transthoracic approach and instrumented fusion. To our knowledge, this is the first video documenting a purely transdural approach for resection of an intradural disc herniation. The patient consented to the surgical procedure and to the use of intraoperative video for education purposes.