Transdural herniated lumbar disc disease with muscle patch for closure of durotomy - A Brief review of literature.

PURPOSE: Intradural migration of disc (IDMD) is a rare clinical entity accounting for 0.27-0.33% of all herniated disc diseases. Flimsy or dense adhesion between the ventral dural surface and the opposing posterior longitudinal ligament (PLL) is the principal pathology for intradural migrated disc. The most commonly affected lumbar segments are L4-5 (55%), L3-4 (16%), L5-S1 (10%) and less commonly L2L3 and L1L2. No imaging feature is characteristic and the management protocol of durotomy via an endoscopic method is unclear.

METHODS: An L5S1 disc disease was operated by endoscopic method. Difficulty in separating the dural sac from PLL, dense adhesions prompting sharp dissection at this location and a calcified disc are the earliest evidence of intradural migration. MRI features of an intradural location are loss of continuity of posterior longitudinal ligament, beak-like appearance also known as "Hawk-beak sign", peripheral enhancement around an intradural disc, fluid-filled intradural cyst. Magnification either by Microscope or Endoscope is of importance when dissecting the intradural disc so as to avoid the nerve root injury. Liberal use of fibrin glue and augmentation with muscle patch was performed.

RESULTS: Ambulated by 48h and discharged by 5th day. Two and 9 months follow up showed no evidence of pseudomeningocoele.

CONCLUSION: Autologous muscle patch with fibrin glue for dural rent closure is a simple and effective method which can be performed by endoscopic or minimally invasive approaches. Suturing the dura, being a tedious and cumbersome procedure can be avoided.