Dr. Kenneth Hughes, Los Angeles Plastic Surgeon, evaluates many plastic surgery patients for surgery who may be at increased risk for blood clots or DVTs and pulmonary emboli or VTEs (venous thromboemboli).   Some of these patients must undergo hematologic clearance to determine if having elective plastic or cosmetic surgery is even reasonable.  Beyond the risk assessment and the clearances, decisions must be made about what anticoagulant to administer and how to administer it as well as frequency and timing of doses.  A recent study pooled some of the data from randomized controlled trials to shed more elucidation as to the appropriate time to administer anticoagulation.  However, the study included all types of patients and is very generic in its findings.  Ultimately, they did not find statistically significant difference in the timing of the administration of anticoagulant doses and its association with VTEs or bleeding risks.  To see the full study, follow this link https://www.journalacs.org/article/S1072-7515(21)01927-X/fulltext.

A relevant summary is provided below.  The objective of their study was to evaluate the association between the start time of peri-operative thromboprophylaxis with venous thromboembolism (VTE) and bleeding outcomes.

Study Design
Multiple databases were searched and randomized controlled trials that evaluated VTE and/or bleeding between groups receiving the initial dose of pharmacological thromboprophylaxis at different times pre-operatively, intra-operatively or post-operatively were included. Only trials that randomized patients to the same medication between groups were eligible. Studies on any type of surgery were included. The outcomes of interest were VTE and bleeding.


A total of 22 trials (n=17,124 patients) met eligibility criteria. Pooled results showed a non-statistically significant decrease in the rate of VTE with pre-operative initiation of thromboprophylaxis when compared to post-operative initiation (RR 0.77, 95% CI 0.55-1.08, I2=0%, n=1,933). There was also a non-statistically significant increase in the rate of bleeding with pre-operative initiation compared to post-operative (RR 1.17, 95% CI 0.94-1.46, I2=35%, n=2,752).

This meta-analysis found a non-statistically significant decrease in the rate of VTE and increase in the rate of bleeding when thromboprophylaxis was initiated pre-operatively compared to post-operatively.