Pannus formation in aortic valve prostheses in the late postoperative period

We present three patients who underwent repeat aortic valve replacement for prosthetic valve dysfunction caused by tissue ingrowth in the late postoperative period. These patients (three women aged 48–51 years, mean 49.3 ± 1.53 years) underwent operations for restriction of prosthetic valve leaflet movement by pannus in the left ventricular outflow tract. The interval from the previous operation ranged from 8.0 to 9.6 years (mean 9.6 ± 2.0 years). The symptoms of the patients were New York Heart Association functional class I, II, and IV in one patient each. Diagnosis was made by cinefluoroscopy in two patients and aortography in one patient. The operative procedures consisted of aortic valve replacement (n = 1) and aortic valve replacement with mitral valve replacement (n = 2). Pannus was found at the left ventricular aspect of the prosthetic valve in all patients. In two patients, the pannus directly restricted movement of the leaflet and also severely narrowed the inflow orifice of the prosthetic valve. In the other patient, the pannus had grown at a distance of 7mm from the valve and narrowed the left ventricular outflow tract circularly. The postoperative course was uneventful and all three patients were discharged in a good condition. One patient died of pneumonia 8 months after surgery and the other two patients have remained well and have been followed up for one and a half years. In conclusion, there may be a discrepancy between the clinical symptoms and the grade of subvalvular stenosis caused by pannus. Therefore, it is essential for satisfactory operative results that early diagnosis be made by various means.