Author + information
- Tavenner Dibert,
- Ryan Boggs,
- Arun Chandran,
- Jennifer Co-Vu and
- Dalia Colon-Lopez
For patients with Fontan Procedure, the risk of thrombosis is approximately 1-33%. Thromboses are a major source of morbidity and mortality for Fontan patients thus immediate proper diagnosis is imperative. CT scan is well-established as a fast and reliable imaging modality for diagnosing pulmonary emboli. Fontan-specific hemodynamic pathways, however, could result in artifacts and inadequate imaging quality. Our study aims to identify a CT technique that can improve thrombus identification and decrease the rate of false positive results.
An IRB-approved retrospective review was performed in Fontan patients who underwent CT scans from 2011 to 2017. CT scans were reviewed for phase of acquisition and accuracy. CT scans were classified as monophasic or biphasic in acquisition. Each CT scan was reviewed by two Pediatric Cardiologists and given a score based on identification of SVC, IVC, Fontan, RPA and LPA. One point was given for each structure resulting in a score range of 0-5. A score of 0-2 was considered non-diagnostic, 3-4 partially diagnostic, and 5 diagnostic. Clinical data including anticoagulation history and cardiac catheterization were reviewed when available. P values were calculated using Fischer's Exact Test.
Forty-six CT scans were performed during the study period. Patients median age at time of CT was 20.5 years (range 4-40 years). Of the 46 scans, 65% (30/46) were monophasic and 35% (16/46) were biphasic. Inter-observer variability was insignificant (p=0.71). Of the biphasic CT scans, 62.5% (10/16) were considered diagnostic versus 27% (8/30) of the monophasic (p value =0.027). There were 2 patients with thrombus found on monophasic CT scan, whose diagnosis was reversed based on follow-up biphasic CT scan.
Fontan flow dynamics are complex and can alter the results of CT scans performed to rule out thromboembolism. Traditional monophasic CT scans result in more non-diagnostic studies and can lead to inappropriate anticoagulation, unnecessary radiation and added cost. In contrast, biphasic CT scans are more accurate and are therefore the diagnostic modality of choice for Fontan thrombus evaluation at our institution.
Poster Hall, Hall A/B
Monday, March 12, 2018, 9:45 a.m.-10:30 a.m.
Session Title: Hear All About It: Fontan
Abstract Category: 09. Congenital Heart Disease: Adult
Presentation Number: 1296-360
- 2018 American College of Cardiology Foundation