Koichi Oga

Congenital atresia of the left coronary ostium: Diagnosis and surgical treatment

SummaryAn 11-year-old girl with congenital atresia of the left coronary ostium underwent coronary artery bypass grafting using the internal mammary artery. Before surgery, the patient complained of syncope on exertion. Exercise electrocardiogram (ECG), two-dimensional echocardiogram, and201Tl myocardial scintigram were useful in establishing the diagnosis. Selective coronary angiograms showed typical findings. Postoperative recovery was uneventful; exercise ECG and stress201Tl myocardial scintigram demonstrated improvement. Internal mammary artery graft is probably better than a saphenous vein graft as a coronary artery bypass graft in childhood and adolescence because of the long-term patency of this type of graft.

Accessory diaphragm: Report of a case associated with atrial septal defect

Summary An accessory diaphragm associated with atrial septal defect is described in a 6-yr-old boy. The patient was asymptomatic but showed chest x-ray abnormalities; accessory diaphragm associated with atrial septal defect was suspected on angiography and bronchography. Operation confirmed the presence of an accessory diaphragm and resection was successful.

Successful correction of a Collett Edwards type II truncus arteriosus after bilateral pulmonary artery banding--a case report.

A case of a 4 year old girl who underwent successful correction of a Collett Edwards type II truncus arteriosus following bilateral pulmonary artery banding is reported herein. The diagnosis of Collett Edwards type II truncus arteriosus was made when she was 5 months of age, after which the bilateral pulmonary artery banding was performed. This proved very effective and enabled elective radial surgery to be done. The radical operation was performed safely by a modified version of Rastelli’s procedure. The patient had an uneventful recovery and is now well with no symptoms one year following her operation.

A pulsatile pump for cardiopulmonary bypass and its clinical use

A pulsatile pump driven by a coil spring, which was designed and constructed by us, is described in this report. It consists of two main parts, a disposable blood chamber and a driving section. The blood chamber has two leaflet valves and a piston, which is covered with two bellofram rolling diaphragms and moves into the housing to draw in and eject the blood. The driving section consists of three cams, an electric motor and a coil spring. The ejection force is wholly produced by the compressed coil spring and is transmitted to the piston in the blood chamber by a rod. This pump allows the ejection pressure, the beat rates, and the stroke volume all to be changed independently. The performance of the pump was tested by using a circulation model where the beat rate was adjusted from 30 to 250 bpm. The output subsequently increased from 0.81/min to 5.71/min and the stroke volume, from 20.4 ml to 36.7 ml. This new pump has been used for clinical cardiopulmonary bypasses in 24 patients of open heart surgery and the pressure traces during perfusion resembled those of the patients’ own hearts.