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

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: Not yet recruiting
• Conditions: Aneurysm Cerebral
• Intervention / Treatment: Other: Observation

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Shaun Gruenbaum, MD, PhD; Phone Number: 904-953-2000; Email: gruenbaum.shaun@mayo.edu

Study Locations

• Italy
  • Roma, Italy, 00185
    • Sapienza University of Rome
    • Principal Investigator: Federico Bilotta, MD, PhD
    • Contact: Federico Bilotta, MD, PhD; Phone Number: +39 06 49911; Email: bilotta@tiscali.it
• 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: Shaun Gruenbaum, MD, PhD; Phone Number: 904-953-2000; Email: gruenbaum.shaun@mayo.edu
      • Principal Investigator: Shaun Gruenbaum, MD, PhD

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Intraoperative Blood Loss	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	The incidence of postoperative hemorrhage detected on CT scans within 48 hours after surgery.	48 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Need for Blood Transfusion	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	Duration of hospitalization from the day of surgery to discharge	From end of surgery to day of discharge, up to 7 days
Surgical complications	Incidence of surgical complications such as infection or reoperation.	From end of surgery to day of discharge, up to 7 days
Subjective Bleeding Severity	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

• Sponsor: Mayo Clinic

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: July 18, 2025
• First Submitted That Met QC Criteria: July 18, 2025
• First Posted (Actual): July 25, 2025

Study Record Updates

• Last Update Posted (Actual): January 7, 2026
• Last Update Submitted That Met QC Criteria: January 5, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: aspirin; craniotomy; postoperative bleeding; aneurysm clipping
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Postoperative Complications; Pathologic Processes; Hemorrhage; Intracranial Arterial Diseases; Aneurysm; Pathological Conditions, Signs and Symptoms; Intracranial Aneurysm; Postoperative Hemorrhage; Investigative Techniques; Methods; Observation
• Other Study ID 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