Impact of Continued Use of Clopidogrel and / or Aspirin on Outcomes in Patients Undergoing Lumbar Spine Surgery. A Prospective Observational Study

BACKGROUND Antiplatelet agents (APAs) are widely prescribed for coronary stenting, primary and secondary prevention of cerebrovascular and coronary artery disease. Dual antiplatelet therapy (aspirin/plavix) has become the mainstay antiplatelet treatment strategy for the prevention of stent thrombosis. Maintaining antiplatelet therapy until the end of the indicated period is crucial for the success of coronary stents. Premature discontinuation of antiplatelet therapy markedly increases the risk of stent thrombosis, a catastrophic event that frequently leads to myocardial infarction (MI), with a death rate of 20-40%. Aspirin is commonly prescribed for lifetime in patients at increased atherothrombotic risk, whereas Plavix is regarded as mandatory until the coronary stents are fully endothelialized, which takes 4-6 weeks for bare metal stents and up to 1 yr for drug-eluting stents. And yet, within the first year after stenting, approximately 5% of patients who have undergone percutaneous coronary interventions (PCIs) will require noncardiac surgery, thus raising dilemmas of APA management: stopping APA treatment before operation to avoid bleeding while risking postoperative stent thrombosis versus maintaining APA therapy perioperatively thus risking extensive blood loss but limiting the risks of postoperative ischemic events.

Current recommendations are that aspirin should not be discontinued pre-operatively, with the exception of brain surgery and certain urological operations in which bleeding may be difficult to control and is therefore life threatening.

The continued use of plavix during the perioperative period significantly increases intraoperative blood loss, re-operations for the control of hemorrhage and transfusions, but does not affect morbidity, mortality, or surgical outcomes.

Most guidelines recommend to postpone invasive procedures until the end of the indication for plavix. Only vital or emergency surgery should be performed on full antiplatelet therapy, with the exception of procedures in which even a small hemorrhage may have disastrous consequences (e.g. intracranial surgery, spinal surgery in the medullary canal, surgery of the posterior chamber of the eye), or procedures involving massive bleeding.

Evidence-based data are needed to guide management of patients in whom early antiplatelet withdrawal is being considered (e.g. those who require non-cardiac surgery). Several studies have been conducted in orthopedic and cardiac surgery, however, to the best of our knowledge, not in spine surgery. This type of surgery might often be semi-urgent and postponing surgery for long time may be problematic.