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.

Abstract

Background: After an atrial switch operation, baffle complications such as stenosis and dehiscence are common. While thromboembolic events attributed to baffle leaks are well known, thrombosis at the pulmonary venous baffle as a source of cardioembolic stroke has not been previously reported.

Case summary: We describe the case of a 43-year-old Caucasian male with recurrent cardioembolic strokes due to a calcified, broken, and thrombosed baffle with floaty, anticoagulant-resistant thrombi adhered to the side of the pulmonary venous return of Mustard patch. Surgery was the only curative option due to thrombi recurrence under different regimes of anticoagulation.

Discussion: 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.