Prosthetic aortic valve thrombosis: Incidence, pathological findings and surgical treatment

BACKGROUND. The authors report their experience on the diagnosis, pathological findings and surgical treatment of prosthetic aortic valve thrombosis. METHODS. Between January 1976 and June 1998, 1289 mechanical prostheses were implanted in aortic position at our institution: a prosthetic obstruction was found in 12 cases. Thrombolysis was performed in two cases and as a result, pathological findings were not available and the patients were excluded from the study. Ten patients underwent surgical treatment. RESULTS. Thrombectomy was performed in one case and prosthetic replacement was done in 9 patients. One patient died postoperatively of low-output syndrome, the others were discharged and no recurrence of thrombosis has been observed at follow-up. Primary thrombosis was found in 6 cases, and pannus formation was observed in 4 patients. All patients with primary thrombosis had a history of poor anticoagulation. Patients with pannus formation had a tilting disc prosthesis. CONCLUSIONS. Use of bileaflet prostheses and adequate anticoagulation can further lessen the incidence of this dreadful complication.