Role of Early Surgical Decompression of the Intradural Space After Cervical Spinal Cord Injury in an Animal Model

Abstract

The role of decompressing the intradural space through a durotomy as a treatment option for acute traumatic cervical spinal cord injury has not been explored in an animal model, to our knowledge. We sought to determine the role of durotomy and duraplasty in the treatment of acute cervical spinal cord injury and its effects on inflammation, scar formation, and functional recovery. Seventy-two adult female Sprague-Dawley rats were assigned to three groups: contusion injury alone, contusion injury with a decompressive durotomy, and contusion injury with a decompressive durotomy followed by placement of a dural allograft. A mild (200-kdyn [2-N]) contusive injury was delivered to the exposed spinal cord at C5. The injured segment was reexposed four hours after injury, and a durotomy with decompression was performed. When a dural allograft was used it was affixed to the surrounding intact dura with use of a fibrin sealant. The Grip Strength Meter was used to assess forelimb function. Animals were killed at two and four weeks, and immunohistochemical analysis was performed to assess scar formation, inflammatory cell infiltration, and lesional volume. Immunohistochemical analysis revealed increased scar formation, cavitation, and inflammatory response in the animals treated only with a decompressive durotomy. Relative to the group with a contusion injury alone, the animals treated with a durotomy followed by a dural allograft had decreased cavitation and scar formation. Lesional volume measurements showed a significantly increased cavitation size at four weeks in both the contusion-only (mean and standard deviation, 12.6 +/- 0.5 mm(3)) and durotomy-only (15.1 +/- 1 mm(3)) groups relative to the animals that had received a dural allograft following durotomy (6.8 +/- 1.4 mm(3)). Functional recovery after acute cervical spinal cord injury was better in animals treated with decompression of the intradural space and placement of a dural allograft than it was in animals treated with decompression alone. These functional data correlated directly with histological evidence of a decrease in spinal cord cavitation, inflammation, and scar formation.