Perioperative Risk in Patients on Chronic Aspirin Undergoing Craniotomy (ASPRIN)

January 5, 2026 updated by: Shaun Gruenbaum, Mayo Clinic

Assessing Surgical Perioperative rIsk in Patients on chRonic aspIrN Therapy Undergoing Elective Craniotomy for Aneurysm Clipping: a Prospective Multi-center Observational Study (ASPIRIN)

This study is looking at how taking aspirin regularly affects bleeding during and after brain surgery. Specifically, it focuses on patients who are having elective surgery to clip a brain aneurysm.

Aspirin is commonly used to prevent heart attacks and strokes, but it can also increase the risk of bleeding. Doctors often face a tough decision: should patients stop taking aspirin before surgery to reduce bleeding risk, or continue it to prevent blood clots?

To help answer this question, researchers will observe 100 patients, some who take aspirin regularly and some who don't, at hospitals in the U.S., Russia, and Italy. They will not change any treatments but will collect information about bleeding during surgery, blood test results, and CT scans after surgery.

The goal is to better understand the risks of continuing aspirin and to help doctors make safer decisions for future patients.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Italy
      • Roma, Italy, 00185
        • Sapienza University of Rome
        • Principal Investigator:
          • Federico Bilotta, MD, PhD
        • Contact:
  • Russia
      • Moscow, Russia, 125047
        • Burdenko National Medical Research Center of Neurosurgery
        • Contact:
          • Alexander Kulikov, MD, PhD
          • Phone Number: +7 499 972-86-68
          • Email: akulikov@nsi.ru
        • Principal Investigator:
          • Alexander Kulikov, MD, PhD
  • United States
    • Florida
      • Jacksonville, Florida, United States, 32224
        • Mayo Clinic Florida
        • Contact:
        • Principal Investigator:
          • Shaun Gruenbaum, MD, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients scheduled for elective craniotomy for cerebral aneurysm clipping

Recruited from three international sites:

Mayo Clinic Florida (USA) Burdenko National Medical Research Center of Neurosurgery (Russia) Sapienza University of Rome (Italy)

Description

Inclusion Criteria:

  • Age > or = 18 years old
  • Patients willing to participate and provide an informed consent
  • Patients undergoing elective craniotomy for cerebral aneurysm clipping
  • Patients on chronic low-dose (75-100 mg) aspirin daily (aspirin group) or not on aspirin therapy for at least 7 days (control group) preoperatively.

Exclusion Criteria:

  • Emergency craniotomy
  • Use of other antiplatelet or anticoagulant medications within 7 days prior to surgery
  • Known bleeding disorders (e.g. hemophilia, thrombocytopenia)
  • History of intracranial hemorrhage unrelated to aneurysm
  • Inability to provide informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Chronic aspirin
Patients on chronic aspirin
Other: Observation
Observation of intraoperative and postoperative outcomes
No aspirin
Patients who are not on aspirin
Other: Observation
Observation of intraoperative and postoperative outcomes

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Intraoperative Blood Loss
Time Frame: From start to end of surgery
Measured by the change in hemoglobin and hematocrit levels from preoperative baseline to immediate postoperative period.
From start to end of surgery
Postoperative Hemorrhage Rate
Time Frame: 48 hours postoperatively
The incidence of postoperative hemorrhage detected on CT scans within 48 hours after surgery.
48 hours postoperatively

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Need for Blood Transfusion
Time Frame: From start of surgery to day of discharge, up to 7 days
The number of patients requiring intraoperative or postoperative blood transfusions.
From start of surgery to day of discharge, up to 7 days
Length of hospital stay
Time Frame: From end of surgery to day of discharge, up to 7 days
Duration of hospitalization from the day of surgery to discharge
From end of surgery to day of discharge, up to 7 days
Surgical complications
Time Frame: From end of surgery to day of discharge, up to 7 days
Incidence of surgical complications such as infection or reoperation.
From end of surgery to day of discharge, up to 7 days
Subjective Bleeding Severity
Time Frame: From start to end of surgery
Rated by the operating surgeon using a standardized 5-point Likert scale (0 = no bleeding to 4 = severe bleeding)
From start to end of surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Mayo Clinic

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 18, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 18, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 25, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 7, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 25-006605

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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