Abstract
We report a three-month-old male case of Down syndrome and complete atrioventricular septal defect (c-AVSD) with a single papillary muscle. After fetal diagnosis of c-AVSD, the patient was delivered normally in the 38th week. Cardiac catheterization and echocardiography showed Rastelli type A c-AVSD with well-balanced ventricles and trivial atrioventricular valve regurgitation. On the other hand, disproportional papillary muscles were seen in the left ventricle (LV) suggesting a functionally single papillary muscle. At the age of three months, intra-cardiac repair using the two-patch method was performed. There was only one papillary muscle in the anterolateral position of the LV, and all cords of both bridging leaflets attached to that muscle. To prevent postoperative stenosis of the left atrioventricular valve (AVV), only the base of the cleft was repaired by making exact apposition zones of both leaflets. Although treatment for pulmonary hypertension and pleural effusion was needed, the patient recovered to a stable condition after the surgery. Finally, the patient was discharged from the hospital with good LV contraction and left AVV function under normal pulmonary arterial pressure. So far, several reports mention a single papillary muscle in c-AVSD morphologically but surgical strategies concerning the left AVV cleft and papillary muscle have not been established yet. Therefore, it is important to develop an adequate procedure to prevent postoperative stenosis and regurgitation in repairing the left AVV portion.
