[Nicks operation for aortic valve dysfunction with pannus formation; report of a case].

A 58-year-old female who underwent an aortic valve replacement 3 years ago was admitted to our hospital. She developed dyspnea in a month. Urgent reoperation was scheduled because an echocardiography demonstrated severe aortic valve regurgitation, and because a cinefluoroscopy showed that a leaflet of the prosthetic valve was restricted. Pannus formation from left ventricular outflow tract caused prosthetic valve insufficiency. An ATS 18 aortic prosthesis was replaced after removing old sewing cuff and surrounding tissue of the aortic annulus as much as possible. However, the coronary orifices were partially covered with the prosthesis. The leaflet rubbed onto the left ventricular outflow muscle specially in opening position. Therefore, an annular enlargement was required. In case of re-replacement of prosthetic valve for small aortic annulus, the annulus was at most same size or smaller than it of the previous operation. It was harmful for the patient whose body surface area was 1.74 m2 to utilize smaller prosthesis because of patient-prosthesis mismatch. We conclude that annular enlargement is useful for reoperarion of small aortic annulus associate with left ventricular outflow hypertrophy.