Low molecular weight heparin use and thrombotic complications in upper gastrointestinal resection for malignancy in a multi-ethnic Asian population

Objective: Epidemiological studies showed substantially lower venous thromboembolic event risk among Asians compared to Caucasians. Yet no Asian guidelines addresses thromboprophylaxis following major surgery for upper gastrointestinal (UGI) malignancy. We aim to evaluate effects of LMWH on thromboembolic and bleeding events in our population. Methods: A retrospective study of all UGI resections for malignancy performed in a tertiary institution in Singapore between 2008 and 2018 was performed. Demographics, clinicopathological data and treatment outcome data were collected and analyzed. Results: A total of 399 patients were included in the study. 210 (52.6%) received postoperative LMWH. Basic demographics-age, gender, BMI, smoking status were comparable. Most patients had cancers stage III or above (42.5% vs 34.6%) cancers. Patients who had open surgery were more likely to receive postoperative LMWH (81.8% vs 67.2%, p = 0.002). Postoperative mortality (3.2% vs 2.9%) and venous thromboembolic events (1.6% vs 1.4%) were similar. However, LMWH use was associated with increased blood transfusion (29.0% vs 12.7%, p < 0.001). Conclusion: Incidence of venous thromboembolism was low and similar irrespective of postoperative LMWH use. However, LMWH use was associated with increased postoperative bleeding. Hence, we do not support routine LMWH for Asian patients undergoing UGI resection for malignancy.