82. The Impact of Chemoprophylaxis and Patient Demographics on Bleeding After Abdominal Body Contouring Procedures

PURPOSE: The global obesity pandemic has resulted in unprecedented demand for body contouring surgery (BCS). Chemoprophylaxis with low molecular weight heparin (LMWH) remains standard of care to prevent post-operative thrombo-embolic events. The impact of chemoprophylaxis on bleeding after BCS remains unclear. METHODS: A single institution retrospective cohort study was conducted on patients who underwent abdominal BCS (abdominoplasty, lower body lift, and/or liposuction). Outcomes examined included estimated blood loss (EBL), hemoglobin drop on the first postoperative day, drain output and quality, length of hospital stay, and the need for surgical evacuation of hematoma or blood/ blood products transfusion. Appropriate statistical tests including chi-square, Wilcoxon signed-rank, and linear regressions were performed using R. RESULTS: A total of 697 patients were included, of whom 136 (19.5%) received no anticoagulation, 324 (46.5%) received only preoperative anticoagulation, 209 (29.9%) received preoperative and postoperative anticoagulation, and 28 (4%) had missing data. Based on univariate analysis, preoperative LMWH was associated with a 45% increase in serosanguinous drain output at day one (145 ml versus 100 ml; p<0.001) but did not correlate with increased risk of bleeding. Male patients had higher odds of hematoma formation (OR 14.8, p<0.001); need for blood (OR 5.13, p<0.001) or fresh frozen plasma (OR 6.15, p<0.001) transfusion, drop in hemoglobin (-2.23±1.06 g/dL versus -1.43±1.01 g/dL, p<0.001), drain output at day one (180 mL versus 130 mL, p<0.001) and total drain output (655 mL versus 380 mL, p<0.001). Patients who underwent previous obesity surgery had higher odds for hematoma (OR 3.24, p=0.011), need for blood (OR 3.26, p=0.002) or fresh frozen plasma (OR 4.83, p<0.001) transfusion, drop in (-1.72±1.15 g/dL versus -1.45±0.98 g/dL, p=0.014), drain output at day one (150 mL versus 130 mL, p<0.001) and total drain output (508 mL versus 360 mL, p<0.001). CONCLUSION: In BCS, preoperative chemoprophylaxis is associated with an increase in serosanguinous drain output without an additional risk of bleeding. Male gender and history of obesity surgery are independently associated with risk of hematoma, hemoglobin drop, drain output and the need for transfusion of blood and associated products.