Preventing blood clots after surgery in patients with inflammatory bowel disease

A Randomized Controlled Trial on the Use of Postoperative Extended Venous Thromboprophylaxis in Patients With Inflammatory Bowel Disease: A Pilot Study

Early Phase 1 Interventional McMaster University · NCT03935451

This study is testing if a blood thinner called apixaban can help prevent blood clots in patients with inflammatory bowel disease after they have abdominal surgery.

Quick facts

PhaseEarly Phase 1
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years and up
SexAll
SponsorMcMaster University Academic / other
Locations2 sites (Hamilton, Ontario and 1 other locations)
Trial IDNCT03935451 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effectiveness of extended venous thromboprophylaxis using apixaban in patients with inflammatory bowel disease (IBD) who are undergoing abdominal surgery. The study aims to reduce the incidence of venous thromboembolism (VTE), such as deep vein thrombosis and pulmonary embolism, which are more prevalent in this patient population. Participants will be randomly assigned to receive either apixaban or a placebo following their surgery. The trial is conducted at Hamilton Health Sciences and St. Joseph's Healthcare Hamilton.

Who should consider this trial

Good fit: Ideal candidates include adults over 18 with a documented diagnosis of Crohn's disease or ulcerative colitis who are scheduled for elective abdominal surgery.

Not a fit: Patients with a history of venous thromboembolism, active bleeding, or contraindications to anticoagulation will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could significantly reduce the risk of life-threatening blood clots in patients with IBD after surgery.

How similar studies have performed: Other studies have shown promising results with extended thromboprophylaxis in surgical patients, suggesting potential success for this approach in IBD patients.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* \>18 years old
* Having documented pathological diagnosis of either Crohn's disease or ulcerative colitis.
* Open or laparoscopic abdominal gastrointestinal surgery
* Elective surgery
* Surgery occurring at Hamilton Health Sciences or St. Joseph's Healthcare Hamilton
* Negative urine beta-hCG for women of childbearing potential

Exclusion Criteria:

* Contraindication to use of postoperative thromboprophylaxis (ie. Previous bleeding on anticoagulation)
* Allergy to apixaban
* History of VTE
* Current clinically significant active bleeding, including GI bleeding
* Hepatic disease associated with coagulopathy and clinically relevant bleeding risk
* Severe renal impairment (eCrCl \<30 ml/min), or undergoing dialysis
* Lesions or conditions at increased risk of clinically significant bleeding (e.g. recent GI bleeding, recent ischemic or hemorrhagic cerebral infarction, active ulcerative GI disease, recent brain, spinal or ophthalmological surgery, bronchiectasis or history of pulmonary bleeding, thrombocytopenia or functional platelet defects, congenital or acquired coagulation disorder)
* Receiving any of the following drugs:

  * Strong inhibitors of both CYP 3A4 and P-gp, such as azole-antimycotics (e.g. ketoconazole, itraconazole, voriconazole, or posaconazole), and HIV protease inhibitors (e.g. ritonavir)
  * Strong inducers of both CYP 3A4 and P-gp (e.g. rifampicin, phenytoin, carbamazepine, phenobarbital, or St. John's Wort)
  * Drug products affecting hemostasis (e.g. NSAIDs, ASA or other antiplatelet agents \[e.g. ASA, clopidogrel, prasugrel, ticagrelor\], SSRIs, or SNRIs)
  * Any other anticoagulant, including unfractionated heparin, LMWH, heparin derivatives, or oral anticoagulants (e.g. warfarin, dabigatran, rivaroxaban)
* Currently receiving therapy for any type of malignancy (e.g. colorectal, breast, lung)
* History of colorectal cancer
* Emergency surgery
* Patients with an indication for anticoagulation before surgery (atrial fibrillation, etc.)
* Enrolled in any other clinical trials or prospective studies where similar outcomes are measured
* Pregnant (i.e. positive pregnancy test and/or self-reported) and/or breastfeeding
* Women of childbearing potential unwilling/unable to participate in appropriate family planning during the treatment period

Where this trial is running

Hamilton, Ontario and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions IBDVenous ThromboembolismCrohn DiseaseUlcerative ColitisPulmonary EmbolismColorectal Disorders
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.