Outcomes of Pulmonary Embolism In Surgical Patients: A Retrospective Cohort Study
Authors: Bose Gauruv , Gandara Esteban , Carrier Marc , Erkens Petra , Rodger Marc , Wells Philip 
Published: October 2019

Abstract
Abstract 3180

Introduction:
Pulmonary embolism (PE) is a continuous risk up to 3 months after surgery. Management of anticoagulation can be challenging in those diagnosed with PE after a major surgical procedure. The aim of this study is to evaluate the outcomes and characteristics of patients diagnosed with PE after a major surgery.

Methods:
A retrospective cohort of consecutive patients with suspected acute PE that underwent computed tomographic pulmonary angiography (CTPA) or lung ventilation/perfusion scans between 1 January 2007 and 31 December 2008 was constructed by two independent investigators by reviewing each patient's diagnostic images. Patients were included in the study if they had a major surgical procedure (admitted to the hospital for more than 24 hours) and developed PE within 12 weeks of the operation. Patients' follow-up for the first 3 months was recorded. Outcomes included major bleeding, as defined by the ISTH guidelines; recurrent venous thromboembolism (VTE), including PE or deep vein thrombosis (DVT); and mortality. The number of days between treatment initiation and major hemorrhage, recurrent VTE, or death, was recorded.

Results:
Out of the 842 patients diagnosed with PE at the Ottawa Hospital within the timeframe of the study, 160 (19%) were diagnosed during the post-operative period and were eligible for this study. The mean age (SD) in years was 63 (±15.5), 53% were males, 37% had a cancer related surgery, 37% had orthopedic procedures, and 31% had emergency procedures. The mean time (SD) from surgery to PE diagnosis was 13 (±11) days. All patients were followed-up until the end of their treatment; six patients were transferred to end of life care. Initial treatment was low molecular-weight heparin (LMWH) in 124 (78%) patients, unfractionated heparin (UFH) was given intravenously in 27 (17%) patients, and 5 (3%) requiered an inferior vena cava (IVC) filter to be inserted as the initial treatment. During the 90 days of follow up, there were 17 major bleeding events (12%), 6 recurrent VTEs (4%), and 15 deaths (9%). Of the 17 bleeding events, 13 of them (76%) occurred within the first two weeks of initiation of therapy. No bleeding events occurred after the first month. Two patients died (11.7%) from bleeding, one intracranial and one gastrointestinal (GI). Bleeding was from the GI tract in 47% of cases. Of the 5 patients with IVC filters, 3 developed recurrent DVT in the first two weeks after IVC insertion. The other 3 recurrent VTEs occurred on patients receiving anticoagulation. All cause mortality was 8.7% at 3 months. Within the first 14 days, 8 patients died (5%): 3 patients from PE. Outcomes did not vary by type of surgery, initial treatment or by presence of malignancy.

Conclusions:
Major bleeding is a common and deadly complication in patients diagnosed with PE after a major surgical procedure. The reported rates of bleeding in this population have varied widely in the literature (between 2 to 9%), according to the type of surgery or population. Our results suggest that alternative triaging and treatment strategies may be indicated in these patients.

Disclosures:
No relevant conflicts of interest to declare.