P106 PREOPERATIVE HYPERCOAGULABLE THROMBOELASTOGRAPHY PROFILES ARE ASSOCIATED WITH POST-OPERATIVE VENOUS THROMBOEMBOLISM IN INFLAMMATORY BOWEL DISEASE PATIENTS
Authors: Vaidya Prashansha , Lee Angus , Lightner Amy , lipman Jeremy , Hull Tracy , Steele Scott , Holubar Stefan 
Published: January 2020

Abstract

Background
We previously reported our pilot experience using thromboelastography (TEG) to assess hypercoagulability in 19 inflammatory bowel disease (IBD) surgical patients. We now report our expanded experience in 55 patients. Our hypothesis is that a hypercoagulable TEG (HyperTEG) profile is associated with post-operative venous thromboembolism (VTE) after surgery for IBD.

Methods
This was a single institution IRB-approved study from June 2018 - July 2019. Preoperative TEGs were obtained as part of routine preoperative labs in consecutive adult patients with either Crohn’s disease (CD) or ulcerative colitis (UC) who underwent major abdominopelvic surgery. Patients were stratified into two groups based on their TEG profiles: Normal vs. HyperTEG. HyperTEG was defined as at least 2 of the 3 abnormal for clotting TEG parameters: 1) low R-value, 2) high degree angle, 3) high maximum amplitude (MA). Clinical data was collected by chart review. Short-term (30-day) surgical outcomes including length of stay (LOS), readmission, reoperations, and major complications were collected. The primary endpoint was VTE. Potential differences between groups were assessed with nonparametric univariate analysis.

Results
A total of 55 IBD patients were included, and 37% (n=20) patients had a HyperTEG profile. The median age at the time of surgery was 40 (21 – 84); 57% (n=31) were women and most patients had CD 67% (n=37). Overall 47% (n=26) patients were receiving oral steroids and 51% had received a biologic within 90 days (15 patients were receiving both), while 12 (22%) of patients were hospitalized pre-operatively. There were no statistically significant differences between baseline or perioperative characteristics between the Normal and HyperTEG patients (Table 1). Post-operatively a total of 3 (5.5%) VTE’s occurred, and the VTE rate was 0 in the Normal group and 15% in the HyperTEG group (p=0.04). Of the VTEs, 1 was a superior mesenteric vein thrombus after subtotal colectomy for UC that was diagnosed pre-discharge, 1 was a deep venous thrombosis in a CD diagnosed pre-discharge, and 1 was a pulmonary embolism in a UC patients diagnosed 1 day post discharge; all patient were on prophylactic enoxaparin at the time.Table 2 shows the TEG parameters in non-VTE and VTE patients. All 3 (100%) VTE patients had a high degree angle (p=0.02) and high coagulation index (p=0.01) while 2 (67%) patients had a low R-value (p=0.13) and high MA (p=0.13). In this series, a preoperative HyperTEG, compared to a preoperative Normal TEG, was associated with the occurrence of post-operative VTE (p=0.04).

Conclusion
We observed that over one third of IBD patients have a hypercoagulable profile preoperatively, with an observed 15% VTE rate, despite prophylaxis with enoxaparin. In this series, an abnormal TEG profile was associated with VTE occurrence after surgery for IBD; our findings suggests that more effective prophylaxis is indicated in these high-risk patients.