L1/2 Intradural Disc Herniation with Compression of the Proximal Cauda Equina Nerves: A Surgical Challenge

Intradural disc herniation (IDH) in the upper lumbar spine is rare. Preoperative radiologic diagnosis can be difficult, making operative planning challenging. We report on a 74-year-old female patient who was diagnosed with an L1-L2 IDH intraoperatively. This case report aims to highlight and discuss the radiological features of IDH and operative challenges when approaching IDH.

A 74-year-old female patient presented to outpatient clinic with a 3-month history of significant intermittent neurological claudication and severe lumbar back pain. Her examination was unremarkable apart from a positive left-sided femoral stretch test. Magnetic resonance imaging (MRI) revealed a large central L1/L2 disc herniation causing significant compression of the thecal sac and proximal cauda equina nerve roots. She underwent an elective posterior L1/L2 lumbar exploration. Intraoperatively, identification of the disc was difficult, which led to inadvertent cerebrospinal fluid leak after incision of what was thought to be a disc bulge. Further exploration revealed an intradural disc that was removed via durotomy. The thecal sac was repaired with sutures and TISSEEL (Baxter, Deerfield, Illinois, USA). Postoperatively, the patient complained of weak left lower limb; MRI revealed residual disc remnants causing compression of the cauda equina. She successfully underwent an urgent revision decompression procedure. She was discharged to rehabilitation on postoperative day 14 with weakness in left knee flexion and extension (MRC grade 4/5) and left ankle plantar- and dorsiflexion (MRC grade 2/5).

Upper lumbar IDH represent a surgical challenge. Intraoperative considerations include identification of the disc, intentional or incidental durotomy, intradural discectomy, and anatomical restrictions of operating at the level proximal to the cauda equina.