TY - JOUR
T1 - A Study of Critical Events That Lead to Spinal Cord Injury and the Importance of Rapid Reversal of Surgical Steps in Improving Neurological Outcomes
T2 - A Porcine Model
AU - Sarwahi, Vishal
AU - Galina, Jesse
AU - Thornhill, Beverly
AU - Legatt, Alan
AU - Pawar, Abhijit
AU - Moguilevich, Marina
AU - Amaral, Terry D.
N1 - Publisher Copyright:
© 2019 Wolters Kluwer Health, Inc.
PY - 2020/2/15
Y1 - 2020/2/15
N2 - Study Design. Porcine model.Objective.To quantify critical vascular and mechanical events that occur before and during an evolving spinal cord injury. Summary of Background Data.Spinal cord injuries are one of the most devastating complications in spine surgery. Intraoperative neuromonitoring changes can occur as a secondary event of spinal cord compression and decrease in spinal cord blood flow (SCBF). Laser Doppler flowmetry has been well validated for measuring blood flow. Methods. Seventeen pigs were studied, 14 of which completed the experiment. Multilevel, midthoracic laminectomies were performed. Laser Doppler flowmetry electrodes were placed on the dura to measure SCBF. Spinal cord injury was induced by incremental balloon inflation in the epidural space. The animals were separated into two groups. After motor-evoked potential (MEP) loss, group A underwent medical interventions and then balloon decompression approximately 20 minutes later. Group B underwent immediate balloon decompression followed by medical interventions. After interventions, wake-up test was performed and computed tomography scan measured thoracic spinal canal volume. Results. Median SCBF changes were seen 15.8 (5.4-25.1) minutes before MEP loss. However, the 20% threshold interval was often reached before. At the 20% threshold, median pressure was 7 psi, balloon volume was 0.5 cm3, and 50% of the spinal canal was compromised. In group A, no pigs moved and all had pathology indicating ischemia. In group B, 9 of 10 were found to be moving their hind legs with 7 indicating ischemia. Conclusion. Compression spinal cord injury is the end of a cascade involving increasing intracanal pressure, decreasing canal volume, and hypoperfusion. Rapid relief of compression leads to MEP return. SCBF monitoring can detect ischemia preinjury, giving surgeons an opportunity for early intervention. Level of Evidence: 4.
AB - Study Design. Porcine model.Objective.To quantify critical vascular and mechanical events that occur before and during an evolving spinal cord injury. Summary of Background Data.Spinal cord injuries are one of the most devastating complications in spine surgery. Intraoperative neuromonitoring changes can occur as a secondary event of spinal cord compression and decrease in spinal cord blood flow (SCBF). Laser Doppler flowmetry has been well validated for measuring blood flow. Methods. Seventeen pigs were studied, 14 of which completed the experiment. Multilevel, midthoracic laminectomies were performed. Laser Doppler flowmetry electrodes were placed on the dura to measure SCBF. Spinal cord injury was induced by incremental balloon inflation in the epidural space. The animals were separated into two groups. After motor-evoked potential (MEP) loss, group A underwent medical interventions and then balloon decompression approximately 20 minutes later. Group B underwent immediate balloon decompression followed by medical interventions. After interventions, wake-up test was performed and computed tomography scan measured thoracic spinal canal volume. Results. Median SCBF changes were seen 15.8 (5.4-25.1) minutes before MEP loss. However, the 20% threshold interval was often reached before. At the 20% threshold, median pressure was 7 psi, balloon volume was 0.5 cm3, and 50% of the spinal canal was compromised. In group A, no pigs moved and all had pathology indicating ischemia. In group B, 9 of 10 were found to be moving their hind legs with 7 indicating ischemia. Conclusion. Compression spinal cord injury is the end of a cascade involving increasing intracanal pressure, decreasing canal volume, and hypoperfusion. Rapid relief of compression leads to MEP return. SCBF monitoring can detect ischemia preinjury, giving surgeons an opportunity for early intervention. Level of Evidence: 4.
KW - laminectomy
KW - laser Doppler
KW - motor-evoked potentials
KW - neuromonitoring
KW - spinal canal compromise
KW - spinal cord blood flow
KW - spinal cord injury
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U2 - 10.1097/BRS.0000000000003229
DO - 10.1097/BRS.0000000000003229
M3 - Article
C2 - 31513108
AN - SCOPUS:85072217975
SN - 0362-2436
VL - 45
SP - E181-E188
JO - Spine
JF - Spine
IS - 4
ER -