Comparison of oral anticoagulants with injectable anticoagulants for prophylaxis of thrombosis in patients undergoing laparotomy surgery

compare the efficacy and safety of oral apixaban with subcutaneous enoxaparin for prevention of postoperative venous thromboembolism in women undergoing gynecologic oncology laparotomy.

This is a randomized, controlled, parallel-group, open-label clinical trial with a 1:1 allocation ratio. Participants will be randomized individually using simple randomization through www.randomization.com. No blinding will be performed because the interventions have different routes of administration.

The trial will be conducted in the Gynecologic Oncology Department of Kowsar Hospital, Urmia. Eligible patients will be enrolled after written informed consent and randomly assigned to receive either oral apixaban or subcutaneous enoxaparin. Outcomes will be assessed during follow-up according to the study protocol.

Participants will be women aged 18 y/o or older with uterine, ovarian, or cervical cancer who undergo laparotomy and are able to follow a 28-day medication regimen. Patients must sign written informed consent. Patients with hypersensitivity to apixaban or enoxaparin, previous vascular events, previous long-term immobility or limb fracture, diseases predisposing to bleeding or thrombosis, or previous anticoagulant use before enrollment will not be included.

Intervention group: Apixaban 2.5 mg oral tablet twice daily for 28 days after discharge. Control group: Enoxaparin 40 mg subcutaneous injection once daily for 28 days after discharge.

The main outcome is symptomatic venous thromboembolism, including deep vein thrombosis or pulmonary embolism, within 30 days after surgery. Secondary outcomes include bleeding events, medication adherence during the 28-day prophylaxis period, and patient costs.

Participants will be randomly allocated to two study groups with a 1:1 allocation ratio. The unit of randomization is the individual participant. Simple randomization will be performed using the website [www.randomization.com](http://www.randomization.com). No stratified randomization will be used. The random sequence will be generated before participant enrollment. Eligible participants will be assigned to either the apixaban group or the enoxaparin group according to the generated random sequence. Allocation concealment will be maintained by using coded group assignments until the time of allocation. For data analysis, the groups will be coded as Group X and Group Y to reduce analysis bias.

Deidentified individual participant data related to the main study outcomes will be available upon reasonable request after publication of the final results. Shared data may include demographic variables, treatment group, occurrence of venous thromboembolism, bleeding events, medication adherence, and treatment costs. The study protocol, statistical analysis plan, informed consent form, clinical study report, and data dictionary will also be available upon reasonable request. Data will be shared only with researchers whose proposed use of the data is approved by the study investigators and, if required, by the relevant ethics committee. Data will be provided for scientific and non-commercial purposes only, after signing a data use agreement.

The deidentified individual participant data and supporting documents will become available 6 months after publication of the final study results and will remain available for 5 years.

The data and documents will be available to qualified researchers affiliated with academic, clinical, or research institutions for scientific and non-commercial purposes.

Data and documents will be shared only after approval of a written research proposal by the study investigators. The proposed analysis should be scientifically valid and related to venous thromboembolism prophylaxis, bleeding events, medication adherence, treatment costs, or related clinical outcomes. The applicant must agree not to attempt to identify participants and not to share the data with third parties. A data use agreement must be signed before data transfer.

Requests should be sent by email to the principal investigator, Dr. Arezou Divband, Urmia University of Medical Sciences. Email: divband.arezou@gmail.com. Requests should include the applicant’s affiliation, research proposal, planned analysis, and required documents or data.

The applicant should submit a written request by email, including the research objective, requested data or documents, analysis plan, institutional affiliation, and ethics approval if required. The request will be reviewed by the study investigators within 4 weeks. If approved, the applicant will be asked to sign a data use agreement. After completion of the agreement, the approved deidentified data or documents will be provided within 2 to 4 weeks.

Shared data will be deidentified and will not include names, national identification numbers, phone numbers, addresses, or other direct identifiers.