Non-instrumented extradural lumbar spine surgery under low-dose acetylsalicylic acid: a comparative risk analysis study

PURPOSE: Coronary artery disease (CAD) affects over one-third of adults and is the leading cause of overall mortality and morbidity. Acetylsalicylic acid (ASA) is widely used in the prevention of CAD. As the population continues to mature, the number of patients presenting for spinal surgery that are under ASA treatment is rising. Studies investigating the outcome of lumbar spine surgeries without discontinuation of ASA therapy are lacking. The purpose of this study is to evaluate the peri- and postoperative bleeding and cardiovascular complication rates of patients undergoing non-instrumented, extradural, lumbar spine surgery with or without discontinuation of low-dose ASA. METHODS: We retrospectively compared the intra- and postoperative blood loss, morbidity, mortality, blood transfusion requirements and hematologic findings in the ASA group (40 patients) and the control group (62 patients). The diagnosis in all patients was either lumbar disc herniation or spinal canal stenosis. RESULTS: Intraoperative blood loss was 221 ml in the ASA group and 140.16 ml in the control group, showing no statistical difference (p = 0.08). Postoperative blood loss was 146.58 and 167.97 ml in the ASA and control groups, respectively, also without statistical difference (p = 0.76). In the ASA group one patient developed a postoperative epidural hematoma needing revision surgery, while in the control group no postoperative epidural hematomas were seen (p = 0.40). In addition, blood transfusion requirements, hematologic findings, morbidity and mortality showed no significant difference. CONCLUSION: The continuation of ASA treatment in patients undergoing non-instrumented extradural lumbar spinal surgery seems to be safe and its perioperative continuation might therefore be recommended. Further studies confirming these results are needed.