An Unusual Case of Transdural Herniation of a Lumbar Intervertebral Disc: Diagnostic and Surgical Challenges

Intradural lumbar disc herniation is rare, with an incidence of 0.3%–1%, but has been well reported in the literature. Transdural migration of the disc penetrating both ventral and dorsal dura is extremely rare, and there is a dearth of literature in the pathophysiology and surgical management of transdural herniation. Lack of knowledge on this type of presentation can cause intraoperative surprises and inadvertent cauda equina root injuries and lead to prolonged operative time. We report 1 such case, describe our surgical experience, and discuss the pathological mechanisms and signs. A 30-year-old woman presented to outpatient clinic with chronic cauda equina syndrome due to massive L4-L5 disc herniation. L4-L5 decompression and transforaminal lumbar interbody fusion were planned. Unexpectedly, however, surgery revealed a transdural herniation, which was effectively managed with laminectomy, extension of durotomy, discectomy, repair of both dorsal and ventral dura, and interbody fusion, but at the expense of prolonged surgical time. Transdural herniation of a lumbar disc is very rare presentation. It can be effectively managed with laminectomy, extension of durotomy, discectomy and repair of both dorsal and ventral dura. It can be diagnosed by magnetic resonance imaging preoperatively only if read with suspicion of such presentation.