General Session VI - Pelvic Venous Disorders and Venous Thromboembolism
Quickshot: Incidental DVT Diagnosed on Lower Extremity CT Is a Rare but Clinically Impactful Finding
Tuesday, March 5, 2024
2:13 PM – 2:19 PM EST
Location: Tampa Bay Ballroom Salons 1-4
Objective: In the setting of a known thrombotic event, computed tomography (CT) scans provide reasonable sensitivity for the diagnosis of deep venous thrombosis (DVT). However, the incidence and accuracy of a DVT diagnosis on CT scans not targeted for the detection of DVT is not well described. Additionally, the clinical impact of DVTs incidentally identified on CT is unknown.
Methods: In this single institution retrospective study, we queried all CT scans of the lower extremities performed over a 10 year period. Regressive computer analysis was utilized to identify CT reports mentioning “deep venous thrombosis”. CT reports were then manually reviewed to confirm the presence of a DVT. Patient demographic factors and relevant medical and surgical history were obtained through chart review. Followup information was obtained for 1 year following the incident CT and included treatment course, additional imaging, and adverse events. An incidental DVT was one identified in a patient in whom the DVT was not noted on a prior study and for whom the study indication did not include concern for DVT or PE.
Results: Out of 16,637 lower extremities CT scans queried, 37 study reports identified a DVT. However, only 13 patients had a finding of an incidental DVT (10-year incidence of 0.08%). Among these 13 patients, 11 (84.6%) underwent additional imaging, including 9 that had subsequent venous duplex and 2 that had subsequent CT scans. Among those with a subsequent duplex, DVT was not identified in 88.9% (8/9) while in 11.1% (1/9), DVT was confirmed. Among those with subsequent CT scan, DVT was not identified in 50% (1/2) and confirmed in 50% (1/2). Out of the 13 patients with incidental DVTs, 3 (23.1%) patients were initiated on anticoagulation based on their initial CT findings alone. Among these 2 (66.7%) did not experience any complications from their DVT or anticoagulation regimen. One (33.3%) did experience major bleeding complications, requiring additional procedures.
Conclusions: Incidental DVTs are a rare finding on lower extremity CT scans. Most patients receive additional imaging to confirm the CT findings, with over 80% of cases confirmed to be artifact. However, our study identified that 23% of patients were initiated on anticoagulation due to the CT findings, with a 33% rate of significant complications. These findings suggest that clinicians may benefit from additional guidance regarding the role of repeat imaging in patients with incidentally diagnosed lower extremity DVTs.
