ASMBS updated position statement on prophylactic measures to reduce the risk of venous thromboembolism in bariatric surgery patients

Venous thromboembolism (VTE) is a major cause of morbidity and mortality after bariatric surgery, most often occurring after discharge within 30 days after surgery.

To determine the risk factors associated with VTE after either sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) and to develop a Bariatric Hypercoagulation Score (BHS) to predict 30-day adverse postoperative outcomes.

University hospital.

Using 2015–2018 data from the Metabolic and Bariatric Surgery Quality Improvement Program, a BHS was created by performing a logistic regression of “venous thromboembolism.” The variables with the highest odds ratio (OR) were selected for the SG and RYGB groups. Then, the 30-day outcomes of low-risk (0–1), average-risk (2–3), and high-risk (≥4) BHS were compared.

Similar risk factors for VTE were found in both the SG and RYGB groups; the highest OR was shown by history of deep vein thrombosis (SG: 3.54, RYGB: 3.05). Other related factors in both groups were history of pulmonary embolism, prolonged length of stay, Black race, and male sex. Conversely, unique risk factors such as dialysis (OR 1.81) was found in the SG group; meanwhile, prolonged operative time (OR 1.50) and age >60 years (OR 1.28) were for the RYGB group. When comparing the 30-day outcomes, BHS ≥4 had a significantly higher rate of complications (P < .001).

SG and RYGB have some risk factors in common for VTE; however, dialysis was associated only with SG, and prolonged operative time and age >60 years were associated only with RYGB. BHS ≥4 showed higher 30-day adverse outcomes. The VTE-correlated variables require special consideration when assessing patients undergoing SG and RYGB.

Venous thromboembolism (VTE) is a leading cause of 30-day mortality after metabolic and bariatric surgery (MBS). Multiple predictive tools exist for VTE risk assessment and extended VTE chemoprophylaxis determination.

To review existing risk-stratification tools and compare their predictive abilities.

MBSAQIP database.

Retrospective analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database was performed (2015–2019) for primary minimally invasive MBS cases. VTE clinical factors and risk-assessment tools were evaluated: body mass index threshold of 50 kg/m², Caprini risk-assessment model, and 3 bariatric-specific tools: the Cleveland Clinic VTE risk tool, the Michigan Bariatric Surgery Collaborative tool, and BariClot. MBS patients were deemed high risk based on criteria from each tool and further assessed for sensitivity, specificity, and positive predictive value.

Overall, 709,304 patients were identified with a .37% VTE rate. Bariatric-specific tools included multiple predictors: procedure, age, race, gender, operative time, length of stay, heart failure, and dyspnea at rest; operative time was the only variable common to all. The body mass index cutoff and Caprini risk-assessment model had higher sensitivity but lower specificity when compared with the Michigan Bariatric Surgery Collaborative and BariClot tools. While the sensitivity of the tools varied widely and was overall low, the Cleveland Clinic tool had the highest sensitivity. The bariatric-specific tools would have recommended extended prophylaxis for 1.1%–15.6% of patients.

Existing MBS VTE risk-assessment tools differ widely for inclusion variables, high-risk definition, and predictive performance. Further research and registry inclusion of all significant risk factors are needed to determine the optimal risk-stratified approach for predicting VTE events and determining the need for extended prophylaxis.

Venous thromboembolism (VTE) is the most common cause of death following metabolic/bariatric surgery (MBS), with most events occurring after discharge. The available evidence on ideal prophylaxis type, dosage, and duration after discharge is limited.

Assess metabolic/bariatric surgeon VTE prophylaxis practices and define existing variability.

Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP)-accredited centers.

The members of the ASMBS Research Committee developed and administered a web-based survey to MBSAQIP medical directors and ASMBS members to examine the differences in clinical practice regarding the administration of VTE prophylaxis after MBS.

Overall, 264 metabolic/bariatric surgeons (136 medical directors and 128 ASMBS members) participated in the survey. Both mechanical and chemical VTE prophylaxis was used by 97.1% of the participants, knee-high compression devices by 84.7%, enoxaparin (32.4% 40 mg every 24 hours, 22.7% 40 mg every 12 hours, 24.4% adjusted the dose based on body mass index) by 56.5%, and heparin (46.1% 5000 units every 8 hours, 22.6% 5000 units every 12 hours, 20.9% 5000 units once preoperatively) by 38.1%. Most surgeons (81.6%) administered the first dose preoperatively, while the first postoperative dose was given on the evening of surgery by 44% or the next morning by 42.2%. Extended VTE prophylaxis was prescribed for 2 weeks by 38.7% and 4 weeks by 28.9%.

VTE prophylaxis practices vary widely among metabolic/bariatric surgeons. Variability may be related to limited available comparative evidence. Large prospective clinical trials are needed to define optimal practices for VTE risk stratification and prophylaxis in bariatric surgery patients.

Morbid obesity is one of the major concerns when performing surgeries, due to higher risks of anesthetic complications. Combined spinal and epidural (CSE) anesthesia technique is used effectively in variety of surgical procedures.

Our patient is a 58-year old female with a Body Mass Index (BMI) of 44.53 who presented to the emergency department complaining of an abdominal pain of a renal nature. She was found to have an abdominal mass suggestive of anexial mass or a Gastro Intestinal Stromal Tumor (GIST) and was scheduled for surgery. Due to the risks associated with general anesthesia, a double neuraxial catheter (subarachnoid and epidural) was the anesthitic method of choice.

Overweight and obesity represent a rapidly growing threat to the health of populations in an increasing number of countries. The first report using the double catheter technique described a parturient with a BMI of 76 kg/m2 who had a lumbar Combined Spinal Epidural (CSE) catheter placed for intraoperative anesthesia and postoperative pain management. In the published literature CSE technique use is limited to obstetric procedure of obese females.

In our case it is highlighted how an obese patient, with severe comorbidities that can jeopardize the success of the treatments, can be discharged in a few days by performing an “unconventional” but effective anesthetic technique.