Thrombocytopenia after aortic valve replacement with the Sorin Freedom Solo prosthesis

Thrombocytopenia after implantation of the Sorin Freedom Solo (FS) stentless aortic bioprosthesis has been described previously. Thus, relevant data acquired at the authors' institution were analyzed.

A comparison of platelet counts was made in patients operated on between January and August 2008 following implantation of either the FS valve (n = 26) or a stented pericardial prosthesis (n = 238). Thrombocyte levels were measured before surgery and on days 0, 1, 2, 3, 5 and 7 after surgery; a comparison was made using absolute and hematocrit-adjusted platelet counts. Clinical adverse events were investigated in both groups, and a multivariate analysis was performed to identify predictors for the occurrence of thrombocytopenia.

After implantation of the FS valve, the mean absolute and hematocrit-adjusted platelet counts were significantly lower on days 2, 3, 5 and 7 after surgery. An additional decrease occurred between days 1 and 3 after surgery, but this was not associated with any adverse clinical outcome. Independent determinants for thrombocytopenia were age and the type of aortic prosthesis. Postoperative echocardiography revealed lower gradients after FS valve implantation.

Given the superior hemodynamic performance of the FS valve, and the absence of any adverse effects, implantation with this valve may be justified in selected patients. Further clarification of the mechanisms causing thrombocytopenia is required.