Intraspinal pressure is not elevated after traumatic spinal cord injury in a porcine model sham-controlled trial.

Introduction It has been suggested that intraspinal pressure (ISP) below the dura is elevated following traumatic spinal cord injury (TSCI). The dura can maintain the pressure, a hence a subdural compartment syndrome has been hypothesized to develop regardless of bony decompression. This study aimed to evaluate whether a such intradural compartment syndrome develops during the first 72 hours in a porcine TSCI model. Methods First, in a randomized sham controlled-trial design, longitudinal ISP measurements were performed over a period of 72 h from onset of TSCI. TSCI was inflicted by a weight-drop contusion regime: 75 g rod, 75 mm free fall, 5 min compression of the spinal cord. Second, in a sham controlled dose-response design longitudinal ISP measurements were performed over a period of 16 h from onset of TSCI, using two other contusion regimes: 75 g, 125 mm free fall, 5 min compression; and 75 g, 75 mm, 240 min compression. Animals were kept sedated for the entire course of the study using propofol, fentanyl and midazolam. Results ISP increased in TSCI and sham animals alike, but we found no significant increase in ISP following TSCI compared to the sham group, and we found no relationship between the ISP increase and the severity or duration of the TSCI impact. Conclusion These findings suggest that the subdural swelling of the spinal cord following TSCI is not responsible for the ISP increase measured in our TSCI model, but that the ISP increase was caused by the surgical procedure or the reconstitution of normal CSF pressure.