Remote Cauda Equina Syndrome Due to Overgrowth of Epidural Free Fat Graft: Case Report

Lumbar discectomy is being done in increasing frequency worldwide where formation of epidural scar formation has been known as a common cause of its failure. Application of a free fat graft despite controversies has been widely used to prevent further adhesion and post-laminectomy scarring. Single nerve root compression and cauda equina syndrome due to compressive effect of free fat graft with a few days to weeks after laminectomy is well known early complication of lumbar discectomy. However, late neurological deficit as the result of significant increase of fat graft volume has been not addressed previously in the literature. Herein, the authors present a middle-age man who was admitted with cauda equina syndrome for one day duration developing 11 years after a redo laminectomy for recurrent disc herniation and local stenosis. The MRI obtained urgently revealed significant overgrowth of the free fat graft that had been already used for prevention of scar formation. Piecemeal surgical removal of fat with clearance of the theca and the corresponding nerve roots result in steady but good recovery within a few weeks. To our knowledge, although overgrowth of fat has been reported in other locations, but this is the first example occurring after its application at the site of laminectomy. Therefore, overgrowth of free fat graft should be added to all previously describe unusual complication of lumbar discectomy.