LAUSR

Introduction Morbid obesity is an important risk factor for developing a venous thromboembolic events (VTE) after surgery. Fast-track protocols in metabolic surgery can lower the risk of VTE in the postoperative period by reducing the immobilization period. Administration of thromboprophylaxis can be a burden for patients. This study aims to compare extended to restricted thromboprophylaxis with low molecular weight heparin (LMWH) for patients undergoing metabolic surgery. Methods In this single center retrospective cohort study, data was collected from patients undergoing a primary Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2014 and 2018. Patients operated in 2014–2017 received thromboprophylaxis for two weeks. In 2018, patients only received thromboprophylaxis during hospital admission. Patients already using anticoagulants were analyzed as a separate subgroup. The primary outcome measure was the rate of clinically significant VTEs within three months. Secondary outcome measures were postoperative hemorrhage and reoperations for hemorrhage. Results 3666 Patients underwent a primary RYGB or SG following the fast-track protocol. In total, two patients in the 2014–2017 cohort were diagnosed with VTE versus zero patients in the 2018 cohort. In the historic group, 34/2599 (1.3%) hemorrhages occurred and in the recent cohort 8/720 (1.1%). Postoperative hemorrhage rates did not differ between the two cohorts (multivariable analysis, p  = 0.475). In the subgroup of patients using anticoagulants, 21/347(6.1%) patients developed a postoperative hemorrhage. Anticoagulant use was a significant predictor of postoperative hemorrhage ( p  < 0.001). Conclusion Despite the restricted use of thromboprophylaxis administration since 2018, the rate of VTEs did not increase. This may be explained by quick mobilization and hospital discharge, as encouraged by the fast-track protocol. There was no significant difference in postoperative hemorrhage rates by thromboprophylaxis protocol. Short term use of thromboprophylaxis in metabolic surgery is safe in patients at low risk of VTE.