Bariatric Surgery and the Long-Term Risk of Venous Thromboembolism: A Population-Based Cohort Study

Obes Surg. 2024 Jun;34(6):2017-2025. doi: 10.1007/s11695-024-07236-y. Epub 2024 Apr 30.

Abstract

Purpose: Bariatric surgery is associated with a greater venous thromboembolism (VTE) risk in the weeks following surgery, but the long-term risk of VTE is incompletely characterized. We evaluated bariatric surgery in relation to long-term VTE risk.

Materials and methods: This population-based retrospective matched cohort study within three United States-based integrated health care systems included adults with body mass index (BMI) ≥ 35 kg/m2 who underwent bariatric surgery between January 2005 and September 2015 (n = 30,171), matched to nonsurgical patients on site, age, sex, BMI, diabetes, insulin use, race/ethnicity, comorbidity score, and health care utilization (n = 218,961). Follow-up for incident VTE ended September 2015 (median 9.3, max 10.7 years).

Results: Our population included 30,171 bariatric surgery patients and 218,961 controls; we identified 4068 VTE events. At 30 days post-index date, bariatric surgery was associated with a fivefold greater VTE risk (HRadj = 5.01; 95% CI = 4.14, 6.05) and a nearly fourfold greater PE risk (HRadj = 3.93; 95% CI = 2.87, 5.38) than no bariatric surgery. At 1 year post-index date, bariatric surgery was associated with a 48% lower VTE risk and a 70% lower PE risk (HRadj = 0.52; 95% CI = 0.41, 0.66 and HRadj = 0.30; 95% CI = 0.21, 0.44, respectively). At 5 years post-index date, lower VTE risks persisted, with bariatric surgery associated with a 41% lower VTE risk and a 55% lower PE risk (HRadj = 0.59; 95% CI = 0.48, 0.73 and HRadj = 0.45; 95% CI = 0.32, 0.64, respectively).

Conclusion: Although in the short-term bariatric surgery is associated with a greater VTE risk, in the long-term, it is associated with a substantially lower risk.

Keywords: Bariatric surgery; Obesity; Venous thromboembolism.

MeSH terms

  • Adult
  • Bariatric Surgery* / adverse effects
  • Bariatric Surgery* / statistics & numerical data
  • Body Mass Index
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Obesity, Morbid* / complications
  • Obesity, Morbid* / epidemiology
  • Obesity, Morbid* / surgery
  • Postoperative Complications / epidemiology
  • Retrospective Studies
  • Risk Factors
  • United States / epidemiology
  • Venous Thromboembolism* / epidemiology
  • Venous Thromboembolism* / etiology