Chronic Antiplatelet Use Associated With Increased Blood Loss in Lumbar Spinal Surgery Despite Adherence to Protocols.

There are conflicting reports regarding postoperative bleeding risks associated with discontinuation of antiplatelet therapy at least 7 days preoperatively. Most of the studies in the spine literature are based on surveys or anecdotal evidence. The majority of surgeons discontinue therapy 7 days preoperatively, but this varies widely from 5 to 21 days. The purpose of this retrospective study was to assess whether chronic antiplatelet use is associated with increased intraoperative blood loss, need for transfusion, and perioperative complications. Of 454 patients who underwent elective lumbar spinal surgery, 85 were on antiplatelet therapy and 369 were not. All patients stopped antiplatelet therapy at least 7 days preoperatively with approval from their cardiologist or primary care provider. Multiple regression analysis was performed and corrected for age, sex, antiplatelet therapy, number of levels decompressed/fused/instrumented, preoperative hematocrit, and postoperative hematocrit. Results showed that preoperative antiplatelet therapy, despite at least 7 days of discontinuation, is a statistically significant predictor (P=.04) of increased intraoperative blood loss. Blood transfusion was not associated with antiplatelet use but was associated with the number of levels fused, age, and low preoperative hematocrit (all P<.01). There were no recorded complications in either group. The authors conclude that antiplatelet therapy is associated with an increased risk of intraoperative blood loss in spine patients despite discontinuation at least 7 days preoperatively, but the clinical significance of this is unclear given the lack of association with blood transfusions and perioperative complications. [Orthopedics. 2016; 39(4):e695-e700.].