Aspin: neurosurgical aspirin intervention prognostic study — perioperative continuation versus discontinuation of aspirin in lumbar spinal surgery, a randomized controlled, noninferiority trial
Authors: Zian Ahmed , Overdevest Gijsbert M. , Schutte Pieter J. , Klok Frederikus A. , Steyerberg Ewout W. , Moojen Wouter A. , van der Gaag Niels A. 
Published: February 2024

Abstract
Rationale
Aspirin is typically discontinued in cranial and spinal surgery because of the increased risk of hemorrhagic complications, but comes together with the risk of resulting in an increase of cardiac and neurologic thrombotic perioperative events.

Objective
The aim of this study is to investigate the non-inferiority of perioperative continuation of aspirin patients undergoing low complex lumbar spinal surgery, compared with the current policy of perioperative discontinuation of aspirin.

Study design
A randomized controlled trial with two parallel groups of 277 cases (554 in total).

Study population
Patients undergoing low complex lumbar spinal surgery and using aspirin. All patients are aged >18 years.

Intervention
Peri-operative continuation of aspirin.

Study outcomes
Primary study outcome: composite of the following bleeding complications:

Neurological deterioration as a result of hemorrhage in the surgical area with cauda and/or nerve root compression.

Post-surgical anemia with hemoglobin level lower than 5 mmol/l, requiring transfusion.

Subcutaneous hematoma leading to wound leakage and pain higher than NRS=7.

Major and/or minor hemorrhage in any other body system according to the definition of the International Society on Thrombosis and Haemostasis bleeding scale.

Secondary study outcomes:

Each of the individual components of the primary outcome

Absolute mean difference in operative blood loss between the study arms

Thrombo-embolic-related complications:

Myocardial infarction

Venous thromboembolism

Stroke

Arterial thromboembolism

Further study outcomes
Anticoagulant treatment satisfaction by the Anti-Clot Treatment Scale (ACTS) and general health by the Patient-Reported Outcomes Measurement Information System (PROMIS Global-10) in the pre- and postoperative phase.

Nature and extent of the burden and risks associated with participation, benefit, and group relatedness
Participation in this study imposes no additional risk to patients. Currently, there is no consensus on whether or not aspirin should be discontinued before cranial or spinal surgery. Currently, aspirin is typically discontinued in cranial and spinal surgery, because of a potential increased risk of hemorrhagic complication. An argument not based on a clinical trial. However, this policy might delay surgical procedures or carry the risk of resulting in an increase in cardiac and neurologic thrombotic perioperative events. It is unclear if the possibility of an increase in hemorrhage-related complications outweighs the risk of an increase in cardiac and neurologic thrombotic perioperative events.
Furthermore, the Data Safety Monitoring Board (DSMB) will be asked for safety analysis by monitoring the study.
There are no further disadvantages to participating in this study. Outcome measurements are recorded during admission and regular outpatient visits, and thus, do not require additional visits to the hospital.