Predicting Operative Time of Single-level Lumbar Laminectomy Based on Patient Factors

Study Design: Retrospective chart review. Objective: This study aimed to develop a model for accurately predicting operative time for patients undergoing a single-level lumbar laminectomy by identifying factors associated with increased surgical duration. Summary of Background Data: Efficient use of operative room (OR) time maximizes OR utilization and has significant implications for patients and health care systems. There is little literature investigating factors associated with increased operative time in lumbar laminectomy procedures. Models that predict operative time in spine surgery to promote efficient use of OR resources are lacking. Methods: An assessment of all patients undergoing a single-level lumbar laminectomy over a 5-year period at a single academic institution was completed. Demographic data, medical history, and operative factors were collected for all patients. The total time in the OR, as well as total operative time (incision to skin closure) was collected. Individual mixed models were used to determine significant operative time predictors. These predictors were then compiled into a stepwise regression model with the goal of accurately predicting operative times. Results: Five hundred fifty-eight patients were included in the study. Degree of preoperative stenosis, BMI, fellow as first assistant (rather than a resident), revision procedure, and intraoperative durotomy were all associated with increased operative time and total time in the OR. Utilizing this data, a predictive model for operative time was developed with 89.3% of predictions within +/-30 minutes of actual time. Conclusion: This study demonstrates that accurate estimates of surgical time can be achieved through predictive modeling using preoperative patient factors. Development of predictive models for more common procedures can allow for more efficient use of operating room resources and overall OR utilization. Level of Evidence: Level IV.