[A successful Konno's operation for subaortic stenosis progressed after total correction of partial atrioventricular septal defect associated with polysplenia].

Konno's operation was successfully performed on a small infant, weighing 3.8 kg. She underwent pulmonary artery banding on the 29th day of life under the diagnosis of partial atrioventricular septal defect with a small left ventricle, associated with polysplenia. Intracardiac repair was subsequently performed on the 45th day of life, which included atrial partition and mitral valvuloplasty. Eleven months after the second operation, wedge resection on the narrow subaortic fibrous lesion was done concomitant with mitral revalvuloplasty. However, repeated echocardiac study disclosed progression of subaortic stenosis. Cardiac catheterization performed at 2 years of age showed the pressure gradinet of 90 mmHg between the aorta and the LV. The aortic annulus and the subaortic lesion measured 10 mm and 4 mm in diameter respectively. Severe subaortic stenosis was created by protrusion of abnormal mitral tissue to the LV outflow, in addition by secondary circumferential fibrous tissue growth and hypertrophy of the ventricular septum. Konno's operation using on 18A Carbomedics valve was chosen for the certain relief of the subaortic stenosis. Although the operation required extensive ventriculotomy and septostomy because of the small aortic annulus, the postoperative course was uneventful. Two months after the operation echocardiography showed good LV function and low RV pressure of about 40 mmHg.