Risk factors associated with venous thromboembolism in laparoscopic surgery in non-obese patients with benign disease

Introduction: Few studies have focused on intraoperative positioning as a risk factor for venous thromboembolism (VTE). Positioning that places the legs in a dependent position may be a risk factor. We theorized that the reverse-Trendelenburg position specifically would increase the risk of postoperative VTE. Methods and procedures: 374,017 subjects undergoing laparoscopic surgery in the 2015–2018 NSQIP database were included. Diagnosis of cancer and BMI ≥ 30 were excluded. Subjects were grouped based on positioning: reverse-Trendelenburg (RT), supine (S), and Trendelenburg (T). Results: The RT, S, and T groups consisted of 117,887, 66,511, and 189,619 subjects, respectively. Overall median BMI was 25.7, and 82.8% of subjects were non-smokers. VTE within 30 days postoperative was seen in 0.25% RT, 0.23% S, and 0.4% T (p < 0.0001); 30-day mortality was 0.34% RT, 0.25% S, and 0.19% T (p < 0.0001). After adjusting for potential confounders and other risk factors, RT position was associated with a lower risk of VTE compared to S (OR 1.49 with 95% CI 1.16, 1.93) and T (OR 1.34 with 95% CI 1.15, 1.56) positions. VTE risk was significantly different across the three groups (p = 0.0001). Inpatient procedures had a higher VTE risk vs outpatient (OR 2.49 with 95% CI 2.10, 2.95). Increasing operative time was associated with higher VTE risk [4th (> 106 min) vs 1st (≤ 40 min) quartiles (OR 3.54 with 95% CI 2.79, 4.48)]. Conclusions: Among other risk factors, inpatient procedures and longer operative times are associated with higher VTE risk in laparoscopic surgery performed for benign disease in non-obese patients. The risk was significantly different across the three positioning groups with lowest risk in the RT group and highest risk in the S group.