High-Risk Bariatric Venous Thromboembolism Prophylaxis Practice Patterns

Howard I Pryor II, MD, Elissa Lin, Adam Singleton, Khashayar Vaziri, MD. George Washington University

Background: Bariatric surgical patients are considered to be at high risk for the development of peri-operative venous thromboembolism (VTE). However, no consensus regarding the specific factors that place bariatric patients at high risk for VTE exists. Since VTE disease can progress from silent events to lethal emboli without much warning, prophylaxis is the best treatment. We sought to identify the factors surgeons use to stratify patients as high-risk for VTE and the current practice patterns of VTE prophylaxis in the high-risk bariatric patient.

Methods: Members of The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) were surveyed regarding their practices in the prophylaxis of VTE in high-risk bariatric patients.

Results: 385 members of SAGES completed the survey. Of those, 313 (82.2%) reported themselves as bariatric surgeons. The majority of respondents were from the United States (75.8%). Twenty-six percent performed < 50 bariatric cases, 31.6% performed 51- 100 cases, and 42.8% performed > 100 cases annually. Of those surveyed, 98.7% performed their procedures laparoscopically. Respondents considered patients with the following factors at high risk for VTE: history of DVT/PE (99.7%); known hypercoaguable state (99.7%); severe immobility (98.7%); BMI > 55 (88.4%); and PaO2 < 60 mmHg (65.9%). A previous history of DVT/PE was considered (69.9%) the most significant single risk factor. Fifty-three percent of surgeons routinely screened high-risk patients pre-operatively for DVT. Of those, 61.5% relied on examination alone, whereas 38.5% relied on ultrasonography. Only 23.8% of respondents routinely screened patients for a previously unidentified hypercoaguable state. Of those surveyed, 92.2% used preoperative chemical prophylaxis, with the majority (51.9%) using subcutaneous heparin (SQH). Intra-operatively 96.2% of respondents placed sequential compression devices (SCD) on their patients. Post-operatively, 91.6% of surgeons used SCD on their patients and 97.0% used chemical prophylaxis with SQH the preferred agent (51.0%). Of those using chemical prophylaxis, post-operative dosing typically started on post-operative day one (69.6%). Chemical prophylaxis was discontinued on discharge in most cases (49.8%), however, 45.0% of surgeons continued post-operative prophylaxis as an outpatient. Of those discharging patients on chemical prophylaxis, treatment was typically (60.4%) discontinued between 2 and 4-weeks. The pre-operative placement of inferior vena cava (IVC) filters was reported at a rate of 28.4%. Of the IVC filters placed, 98.8% were retrievable and 55.2% were removed at 30-90 days postoperatively.

Conclusions: The majority of SAGES members surveyed consider morbidly obese patients with history of DVT/PE; known hypercoaguable state; severe immobility; BMI > 55; and PaO2 < 60 at high risk for developing peri-operative VTE. Most respondents routinely use SQH VTE prophylaxis. Post-operative dosing typically started on post-operative day one. Almost half of surgeons discontinued chemical prophylaxis on discharge. Of those who discharge patients on chemical prophylaxis, treatment is typically discontinued within 2 to 4-weeks. One third of surgeons placed IVC filters pre-operatively and nearly all were retrievable. The majority of filters were removed at 30-90 days post-operatively. The identification of these practice patterns can serve as the basis to validate the best approach to bariatric surgical candidates with these risk factors.