Efficacy and Safety of Low Molecular Weight Heparin and Mechanical Thromboprophylaxis in Immediate Implant-based Breast Reconstruction: A Retrospective Comparative Analysis.

Background/aim: Low molecular weight heparin (LMWH) is widely employed to prevent postoperative venous thromboembolism (VTE). This study aimed at analyzing LMWH use and evaluating its efficacy and safety in immediate implant-based post-mastectomy breast reconstruction.

Patients and methods: A monocentric retrospective analysis was conducted on patients who underwent immediate implant-based breast reconstruction (IBR) from January 2021 to December 2023. Preoperative characteristics, Caprini score, type of mastectomy procedure, administration of LMWH, postoperative outcomes, and any adverse events linked to LMWH usage, with particular attention to hematoma or VTE, were collected and analyzed.

Results: A total of 211 breast procedures were performed on 179 patients - with a mean age of 50.9 years (SD 12.3) and a mean Caprini score of 6.8 (SD 1.4). In total, 133 patients received LMWH by subcutaneous injection (enoxaparin 40 mg/day) post-operatively and 46 only had mechanical thromboprophylaxis. The overall complication rate was higher but statistically significant in the LMWH group with 27.8% compared to 17.4% in the no-LMWH group (p=0.159). Hematoma occurred in 17 patients (12.8%) in the LMWH group compared to two (4.4%) patients in the no-LMWH group (p=0.164). Moreover, 15 (11.2%) patients who received LMWH required reoperation compared to one (2.2%) in patients who did not receive LMWH (p=0.074). There were no VTE events in either group.

Conclusion: There were no significant differences in complications and especially hematoma rate in patients who received LMWH after mastectomy and immediate IBR, compared to patients who did not. Moreover, no difference in VTE rate was observed across groups.