Duration and Magnitude of Postoperative Risk of Venous Thromboembolism after Cholecystectomy: A Population-Based Cohort Study.

BACKGROUND: This study aimed to identify the burden and risk of venous thromboembolism (VTE) associated with cholecystectomy in England.

METHODS: An historical cohort study of cholecystectomy patients from 2001 to 2011 was undertaken using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data. Crude rates and adjusted hazard ratios (HRs) were calculated for risk of VTE following cholecystectomy using Cox regression.

RESULTS: 24,677 patients were identified with a rate of VTE in the first year following cholecystectomy of 2.80 per 1,000 person years (95% CI 2.18-3.59). Patients aged ≥70 vs. aged < 50 had 8.3-fold increase in risk of VTE (HR 8.27, 95% CI 3.72-18.35); patients with body mass index (BMI) > 30 vs. BMI < 30 had 2.4-fold increase in risk (HR 2.42, 95% CI 1.40-4.18); open vs. laparoscopic operation had 3-fold increase in risk (HR 2.94, 95% CI 1.55-5.55). Compared to general population, VTE risk was the highest in the first 30 days post-operatively with 9.9-fold risk following emergency cholecystectomy and 4.5-fold risk after inpatient cholecystectomy (HR 9.90, 95% CI 4.42-22.21; HR 4.54, 95% CI 2.85-7.21).

CONCLUSIONS: Cholecystectomy is associated with a low absolute risk of VTE and we have identified high risk groups including the elderly, obese and those having open surgery.