Clinical question: Does duration of surgical procedure influence venous thromboembolism (VTE) risk?
Background: The relationship between surgical procedure length and VTE risk has not been vigorously assessed, although it has been postulated that longer procedures are associated with increased VTE risk. Improved understanding of this relationship may be beneficial to surgeons deciding on VTE prophylaxis strategies or determining whether to perform coupled procedures.
Study design: Retrospective cohort study.
Setting: Data collected from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP).
Synopsis: Study authors divided 1,432,855 surgical cases during which general anesthesia was administered for a specified duration into five quintiles based on length of operative time, defined as the period during which a patient was under general anesthesia. The primary outcome was the development of a VTE within 30 days of the procedure, defined as deep venous thrombosis (DVT), pulmonary embolism (PE), or both. Logistic regression analyses were performed to assess the relationship between procedure length and VTE occurrence.
The middle quintile of procedures carried a VTE rate of 0.86%. There was a significant association between procedure duration and VTE risk when the first and second quintiles, and fourth and fifth quintiles, were compared to the middle quintile. The association was present across all surgical subspecialties.
Bottom line: Longer duration of surgical procedures is associated with increased VTE risk.