Sathananthan G, Johal N, Verma T, et al. - By performing this retrospective review of adult patients who underwent the Fontan procedure (aged > 18 years), researchers assessed the incidence of Fontan circuit thrombus and the proportion of silent thrombus. They also looked for any link between Fontan circuit thrombus and markers of Fontan circulatory dysfunction and investigated the link of Fontan circuit thrombus with adverse cardiac consequences. The presence of Fontan circuit thrombus was revealed in 15 of 67 patients (22%). A 36% incidence was reported in those suspected to have Fontan circuit thrombus, and 14% incidence was reported in those with no clinical/echocardiographic suspicion. In the classic/modified group vs in the total cavopulmonary connection group, the time from Fontan surgery to Fontan circuit thrombus diagnosis was reported to be 22 ± 6 years vs 14 ± 8 years, respectively. Adverse cardiac results were reported in relation to Fontan circuit thrombus, but no difference in Fontan circulatory dysfunction markers was revealed. Strongly considering routine surveillance of the Fontan circuit was recommended, given the incidence of Fontan circuit thrombus and link with adverse cardiac consequences. As a result of thrombus identification, anticoagulation implementation/optimization should happen, along with screening/intervention for reversible Fontan circulatory problems in an effort to avert adverse cardiac consequences.