Description

Postoperative venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE), is a major and preventable cause of morbidity and mortality after surgery. Patients undergoing emergency exploratory laparotomy are at especially high risk due to prolonged operative times, systemic inflammation, and immobility. While low-molecular-weight heparins (LMWH), such as enoxaparin, are the current standard for prophylaxis, direct oral anticoagulants such as rivaroxaban offer potential advantages in terms of ease of administration, compliance, and patient comfort.

This randomized controlled trial was designed to compare the efficacy and safety of once-daily oral rivaroxaban (10 mg) with once-daily subcutaneous enoxaparin (40 mg) in preventing postoperative DVT in adult patients undergoing emergency exploratory laparotomy at Mayo Hospital, Lahore.

Eligible patients were adults aged 18-80 years undergoing emergency laparotomy for traumatic or non-traumatic indications and expected to remain immobile for more than 24 hours postoperatively. Patients with pre-existing DVT, morbid obesity (BMI ≥40), active bleeding risk, mechanical ventilation, myocardial infarction, cerebrovascular accident, or current anticoagulation therapy were excluded.

Participants were randomized using a computer-generated sequence with allocation concealment. Rivaroxaban or enoxaparin was given for 7 days postoperatively, in addition to standard perioperative care and mechanical prophylaxis.

The primary outcome was the incidence of DVT as confirmed by duplex color Doppler ultrasound on postoperative days 5 and 10. Any noncompressible or indistinct venous segment was scored as positive for DVT. Wells scores were also recorded to stratify risk.

The secondary outcomes included bleeding complications, duration of hospital stay, time to ambulation, and cost comparison between the two regimens. Safety assessments focused on clinically significant bleeding events and other adverse reactions.

A total of 212 patients were enrolled (106 in each arm). On day 5, rivaroxaban showed a significantly lower rate of DVT compared to enoxaparin (3.8% vs 12.3%). By day 10, the difference remained significant (8.5% vs 20.8%). Wells scores showed no significant differences between groups. No major bleeding events were reported in either arm.

The findings suggest that rivaroxaban is more effective than enoxaparin in reducing postoperative DVT after emergency exploratory laparotomy without increasing bleeding risk. These results add evidence that rivaroxaban may be a safe and convenient alternative to LMWH for high-risk general surgical patients. However, larger multicenter trials with longer follow-up are needed to confirm safety and evaluate long-term outcomes such as pulmonary embolism and late-onset DVT.