A calcified, eroded, and thrombosed Mustard: recurrent embolic strokes in a patient with dextro-transpostion of the great arteries corrected by atrial switch—case report

A case of recurrent cardioembolic strokes long after Mustard surgery due to thrombi on a heavily calcified pericardial patch is presented. A fracture in the patch led to the exposure of thrombogenic material, which had accumulated around the pacemaker (PM) leads on the systemic venous side of the baffle. This exposure allowed thrombotic material to reach the pulmonary venous side, ultimately entering the subaortic right ventricle and the systemic circulation. In the Mustard procedure, the material used for the baffle construction is prone to degeneration and calcification over time. We hypothesize that chronic mechanical stress from the PM leads might have contributed to the gradual erosion and fracture and consequently thrombosis of the heavily calcified patch, leading to recurrent strokes. Surgery became necessary as aggressive anticoagulation failed to prevent thrombus recurrence.