Occluding Thrombi of the Left Atrium

Report of Four Cases Treated Surgically

¹ The Department of Surgery, Section of Cardiovascular Surgery, Rhode Island Hospital.

Among the morphologic variants of left atrial thrombi, the unattached ball or pedunculated thrombus poses the greatest problem in surgical management and judgment. Clearly, large occluding thrombi require an open technique for their safe removal. On the other hand, a number of intermediate-sized thrombi can be treated surgically by less elaborate means when encountered unexpectedly. Four clinical cases encountered among 105 operations for the relief of mitral stenosis at the Rhode Island Hospital are presented to illustrate the problem in diagnosis and surgical management. The surgical technique employed in three patients in whom free-floating intra-atrial thrombi were encountered unexpectedly was chosen in an effort to avoid fragmenting the thrombus. It took advantage of a tight mitral stenosis which effectively restricted the thrombus to the atrium and created an elevated atrial pressure sufficient to expel the thrombus through an enlarged but suture-controlled atriotomy. A fourth patient was suspected of having an occluding thrombus and underwent an open operation.