Intraoperative thrombus formation in the artificial tube graft in a fenestrated extracardiac Fontan procedure—to trust our eyes or instincts?

Appearance of a thrombus in the graft intraoperatively during Fontan surgery is not reported and warrants careful evaluation. Our patient was an 18-year-old lady who underwent fenestrated extracardiac Fontan surgery. Intraoperatively, transesophageal echocardiography revealed an echogenic structure inside the conduit. Whether it was an artifact or a thrombus was debated and ruled in favor of an echocardiographic artifact owing greatly to the absence of any reported cases of intraoperative Fontan conduit thrombus. The patient had an uneventful recovery though as a team we are convinced that it is most likely a thrombus, in retrospect. The absence of similar cases in literature and the significant potential consequences of the event make this case worthy of discussion.