Chylothorax as a Risk Factor for Thrombosis in Adults: A Proof-of-Concept Study.

BACKGROUND: Postoperative chylothorax in children is associated with an increased risk of vascular thrombosis, hypothesized to be from loss of antithrombin into chylous fluid resulting in a hypercoagulable state. In adults, an increased thrombotic risk with chylothorax has not been described. Adults undergoing Ivor-Lewis esophagogastrectomy have two strong thrombotic risk factors-active malignancy and postoperative state-allowing for relative homogeneity in baseline thrombotic risk; therefore, we studied the association of chylothorax with thrombosis in this population.

METHODS: We performed a single-center retrospective cohort study at a tertiary care academic center. Patients included adults undergoing Ivor-Lewis esophagogastrectomy between January 1, 2006, and December 31, 2012. We collected demographics, pleural fluid characteristics, and relevant imaging within 30 days after the operation. Using nominal logistic regression, we studied the effects of chylothorax, age, sex, body mass index, American Society of Anesthesiologists Physical Status Classification, operative duration, and hospital length of stay on the incidence of postoperative thrombosis.

RESULTS: We identified 608 patients who underwent Ivor-Lewis esophagogastrectomy. Of these, 524 (86.2%) had no pleural fluid analysis, 48 (7.9%) had nonchylous effusions, and 36 (5.9%) had chylothoraces, with incident acute vascular thrombosis within 30 days postoperatively occurring in 22 of 524 (4.2%), 2 of 48 (4.2%), and 8 of 36 (22.2%), respectively (p = 0.001). In multivariate analyses, after adjusting for the above factors, chylothorax was associated with significantly higher odds of any vascular thrombosis (odds ratio, 5.46; p = 0.0013) and deep venous thrombosis/pulmonary embolism (odds ratio, 6.76; p = 0.0016).

CONCLUSIONS: Chylothorax is associated with a significantly higher incidence of vascular thrombosis in adults undergoing Ivor-Lewis esophagogastrectomy. Vascular thrombosis was associated with a significantly higher 90-day mortality rate.