The risk of venous thromboembolism in patients with and without leiomyomas undergoing hysterectomy

Abstract

Leiomyomas occur in 80% of women and can require hysterectomy for management. The risk for venous thromboembolism (VTE) is 0.7% for any hysterectomy. However, it has been theorized that large uterine size due to fibroids increases VTE risk due to pelvic vasculature compression. The objective of this study is to evaluate if the risk of VTE of women undergoing surgeries for fibroid-related indications is different compared to women undergoing hysterectomy for non-fibroid-related indications. We also aimed to determine the preexisting incidence of VTE between the groups and identify risk factors for VTE. Patients who underwent hysterectomy by any route at an academic center between January 2019-December 2019 were included. Demographic, pathology, and VTE diagnosis data were assessed. Preoperative VTE occurred prior to surgery. Perioperative VTE occurred within 6 weeks of surgery. Patients with malignancy and known thrombophilias were excluded. A total of 1,029 patients were included, of which 687 patients had fibroids and 342 had none. Patients with fibroids were likely to be older, have higher BMI, larger uterine size, and greater EBL (p<0.05). Of the total cohort, 22 patients (2.1%) had VTE, of which 19 (1.8%) were preexisting, and 3 (0.2%) occurred peri-operatively. Ten of the 22 patients (45%) with preexisting VTE had fibroids; none of whom developed perioperative VTE. The presence of fibroids did not increase the odds of perioperative VTE (OR 0.2, CI [0.02-2.7]). Those with preexisting VTE were more likely to have increased BMI, Charlson Comorbidity Index (CCI), postoperative length of stay, and ASA risk score (P<0.05). In both univariate analysis and logistic model, both fibroids and total uterine size were not associated with preexisting VTE (univariate p= 0.18, p=0.50; logistic model p=0.08, p=0.17 respectively). Higher BMI and ASA score of 3-4 are associated with higher odds of preexisting VTE (1 unit increase of BMI OR 1.06, CI [1.0-1.1]; OR 3.6 [1.4-9.3]). However, specifically in patients with fibroids, only ASA score of 3-4 is associated with higher odds of preexisting VTE (OR 4.2, CI 1.2-15.1). Patients undergoing hysterectomy for fibroid-related indications are not at increased risk for VTE compared to patients undergoing surgery for non-fibroid-related indications. Preexisting VTE in patients with fibroids did not increase the risk for perioperative VTE. Overall, for patients with fibroids, higher ASA scores are associated with VTE event.