Iatrogenic Pseudomeningomyelocele after Lumbar Laminectomies: Report of Cases

ABSTRACT

Two unique cases of delayed nerve root herniation and entrapment into the pseudomeningocele through an unrepaired dural laceration at lumbar laminectomy were reported. Both patients presented with recurred radiculopathy, 3 and 6 years after first operation respectively. Lumbar myelography showed an extradural pseudomeningocele pouch in case 1 while showing no abnormality in case 2. Lumbar MRI in case 1 showed tangled herniated nerve root in the pouch of pseudomeningocele. Lumbar myelographic CT of case 2 showd delayed partial filling of the pseudomeningocele pouch only. Herniation through dural defect and entrapment of nerve root in the pseudomeningocele was nosted during surgery. Surgical correction of the herniated nerve root and dural repair was performed and this correction completely relieved the pain in both patients. These cases demonstrate even a small tear in the spinal dura during laminectomies requires surgical closure to prevent late nerve root herniation. Finally, the possible mechanism of this condition was also discussed.