A new simplified risk assessment model enhances postoperative prophylaxis of venous thromboembolism in Chinese adult patients with inguinal hernia (CHAT-3): A prospective, multicenter, randomized controlled trial

Background: Venous thromboembolism (VTE) significantly affects the prognosis of surgical patients with inguinal hernia. The complex Caprini score, commonly used for postoperative VTE risk assessment, poses practical challenges for surgeons in clinical settings. Methods: The CHAT-3 trial, a prospective, multicenter, randomized controlled trial, compared a simple three-factor model to assess VTE risk against routine practices in post-inguinal hernia surgery (IHS) patients. The patients were randomly assigned (1:1) to the intervention or control arm. The intervention group used the three-factor model to identify patients at moderate or high risk of VTE for subsequent prophylaxis according to clinical guidelines. Both groups were followed for four weeks, with randomization implemented using computer-generated sequences. The primary outcome measured was the rate of VTE prophylaxis. Secondary outcomes included time spent on VTE risk assessment (surgeon self-reported), postoperative D-dimer trends, perioperative VTE occurrence, bleeding events, and the net clinical benefit. Results: Of the 1,109 participants, 508 in the experimental group and 601 in the control group completed follow-up. The three-factor model showed higher VTE prophylaxis rates in all patients (pharmacologic prophylaxis: 26.2% vs. 6.00%, P <0.001) and particularly in those at high risk (pharmacologic prophylaxis: 57.3% vs. 9.50%, P <0.001). The experimental group significantly reduced VTE risk assessment time compared to the Caprini score (1.39±0.55 min vs. 5.73±1.35 min, P <0.001). The experimental group had lower D-dimer levels (0.26±0.73 mg/L vs. 0.35±0.55 mg/L, P =0.028). In the experimental group, the patients did not experience an increased risk of VTE (0% vs. 1.66%, P =0.268) and bleeding (1.18% vs. 0.67%, P =0.558) compared to the controls. There was no significant difference in net clinical benefit, which combined VTE and bleeding events, between the experimental and control groups (1.18% vs. 0.83%, P =0.559). Conclusion: Applying the simple three-factor model in perioperative VTE management could quickly identify the patient with a high risk of VTE and improve the prophylaxis rate of perioperative VTE. Trial registration: XXX Trial registration: ChiCTR2000033769