L1/2 intradural disc herniation with compression of the proximal cauda equina nerves: a surgical challenge

Abstract Background Intradural disc herniation in the upper lumbar spine is rare. Pre-operative radiological diagnosis can be difficult, making operative planning challenging. We report a 74-year-old female patient who was diagnosed with an L1-2 IDH intra-operatively. This case report aims to highlight and discuss the radiological features of IDH and operative challenges when approaching IDH. Case description 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. MRI revealed a large central L1/2 disc herniation causing significant compression of the thecal sac and proximal cauda equina nerve roots. She underwent an elective posterior L1/2 lumbar exploration. Intraoperatively, identification of the disc was difficult which led to inadvertent CSF leak after incision of what was thought to be a disc bulge. Further exploration revealed an intradural disc which was removed via durotomy. The thecal sac was repaired with sutures and tisseel. Post-operatively, she 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 post-op day 14 with weakness in left knee flexion and extension (MRC grade 4/5) and left ankle plantar- and dorsiflexion (MRC grade 2/5). Conclusion 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.