Effect of irrigation technique on the vertebral canal temperature during thoracolumbar hemilaminectomy in dogs: An ex vivo study

Objective To determine the influence of continuous and intermittent bolus irrigation on vertebral canal temperature during thoracolumbar hemilaminectomy. Study Design Ex vivo study. Sample Population Ten canine cadavers. Methods Six consecutive thoracolumbar hemilaminectomies starting at T12‐13 with alternating left‐ or right‐side selection, and alternating continuous or intermittent bolus irrigation were performed in each dog resulting in 30 hemilaminectomies per irrigation technique. Drilling was performed for 15 s followed by a 10‐s pause and resumed until completion of hemilaminectomy. Continuous irrigation consisted of saline delivered at 15 ml/min during drilling. Bolus irrigation consisted of manual delivery of 10 ml saline during the pause. Temperatures were recorded with two sensors placed within the vertebral canal adjacent to target hemilaminectomy site and compared between techniques with a linear mixed model. Results Intermittent bolus irrigation was associated with lower peak vertebral canal temperatures (mean 15.7°C; range 9.4–23.3°C) than continuous irrigation (mean 16.7°C; range 9.6–27.6°C, p = .003) (mean difference of 1.1°C, p = .006). Similarly, mean vertebral canal temperatures remained lower when hemilaminectomies were performed under intermittent rather than continuous irrigation (mean difference of 0.48°C, p = .006, linear mixed model). Conclusion Lower vertebral canal temperatures were maintained during hemilaminectomy with intermittent bolus rather than continuous irrigation. Clinical Significance Both intermittent bolus and continuous irrigation are suitable to prevent elevations in canine vertebral canal temperature during hemilaminectomy.