Abstract Number: PB2364
Meeting: ISTH 2020 Congress
Theme: Venous Thromboembolism and Cardioembolism » VTE Prophylaxis
Background: Patients undergoing bariatric surgery are at an increased risk of venous thromboembolism (VTE), however, the optimal dose of low-molecular-weight heparin for prophylaxis remains uncertain.
Aims: St. Joseph’s Health Care Hamilton utilizes a weight-adjusted tinzaparin dosage (75 units/kg rounded to nearest pre-filled syringe) for post-operative VTE prophylaxis. This study analyzed the safety of weight-adjusted tinzaparin for VTE prophylaxis in bariatric surgery patients at the highest weight class (> 160 kg).
Methods: This was a single center retrospective study involving patients weighing 160 kg or more who underwent bariatric surgery at St. Joseph’s from January 2017 to September 2019. Patients received a single dose of weight-adjusted subcutaneous unfractionated heparin (UFH) [5000 or 7500 IU] immediately prior to surgery, either no prophylaxis or subcutaneous UFH [5000 or 7500 IU] post-operatively and either 10,000 or 14,000 IU Tinzaparin, beginning on the day after surgery, for 10 days. Additionally, intra-operative sequential compression devices could be used at the attending surgeon’s discretion. Outcomes assessed were the occurrence of VTE or major bleeding over 30 days.
Results: Patient characteristics are summarized in Table 1. Of 287 eligible patients, 14 patients did not receive the standard dose of tinzaparin. Reasons for unexpected dosing were due to post-operative complication (n=1), had an indication for an alternate anticoagulant (n=5), and unspecified reasons (n=8). Pulmonary embolism occurred in one patient on post-operative day 1, prior to their first tinzaparin dose; major bleeding events occurred in 6 patients (2%). 24 patients received at least one dose of protocol appropriate tinzaparin but then received at least one dose of an alternative anticoagulant.
| Variable | All patients (n=273) |
| Age (years), mean (SD) | 44 (10) |
| Weight (kg), mean (SD) | 182 (21) |
| Female (%) | 129 (47) |
| Body Mass Index, mean (kg/m2) (SD) | 59 (8) |
| Received estrogen therapy (%) | 27 (10) |
| Procedure (%) Sleeve Gastrectomy Gastric Bypass Duodenal Switch Biliopancreatic Diversion |
171 (63) 80 (29) 21 (8) 1 (0.4) |
| Pre-operative Unfractionated Heparin (%) 7500 IU 5000 IU |
242 (89) 30 (11) |
| Post-operative Unfractionated Heparin (day of surgery) (%) 5000 IU Unspecified |
260 (95) 13 (5) |
| Tinzaparin Dosage (%) 10,000 IU 14,000 IU |
54 (20) 219 (80) |
[(Table 1) Patient Characteristics]
Conclusions: In this study of obese individuals undergoing bariatric surgery the use of weight-adjusted tinzaparin was associated with a lower risk of bleeding (2%) compared to general bariatric surgery (4.4%). These findings support the use of dose-adjusted tinzaparin for VTE prevention in such patients.
To cite this abstract in AMA style:
Li A, Eshaghpour A, Tseng EK, Douketis JD, Anvari M, Tiboni M, Siegal DM, Ikesaka RT, Crowther MA. Weight-Adjusted Tinzaparin for Venous Thromboembolism Prophylaxis in Bariatric Surgery Patients Weighing 160kg or More [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/weight-adjusted-tinzaparin-for-venous-thromboembolism-prophylaxis-in-bariatric-surgery-patients-weighing-160kg-or-more/. Accessed September 21, 2023.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/weight-adjusted-tinzaparin-for-venous-thromboembolism-prophylaxis-in-bariatric-surgery-patients-weighing-160kg-or-more/