Haruo Miyamura

Combined warfarin and antiplatelet therapy after St. Jude Medical valve replacement for mitral valve disease

OBJECTIVES The clinical effect of combined warfarin and antiplatelet therapy on the incidence of stroke and postoperative complications after mitral (plus aortic) valve replacement was studied and compared with that observed with warfarin therapy alone. BACKGROUND It has been reported that combined warfarin and antiplatelet therapy may be effective but may be associated with an increased hemorrhagic risk. Therefore, definite benefits of the treatment in patients with an implanted prosthetic valve have not been clearly documented. METHODS Between January 1980 and December 1992, 195 patients with a St. Jude Medical valve at the mitral (plus aortic) position were assigned to receive treatment with either warfarin alone (125 patients) or warfarin plus antiplatelet agents (70 patients), such as dipyridamole (150 or 300 mg daily, 14 patients) or ticlopidine (200 or 400 mg daily, 56 patients). A minimal dose of aspirin (10 to 40 mg) was added (29 patients) if the maximal platelet aggregation rate by collagen was not reduced. The target thrombotest level was 10% to 20%. RESULTS The two treatment groups were similar with regard to gender and age distribution. The number of patients with atrial fibrillation, left atrial thrombus, history of previous stroke, simultaneous aortic valve operation and previously performed valve procedures were comparable in the two groups. Actuarial survival rate at 10 years was 98.3 +/- 1.7% (mean +/- SD) in the warfarin plus antiplatelet group and 90.3 +/- 3.2% in the warfarin group (p < 0.05 at 1 and 9 to 12 years). The actuarial stroke-free rate at 10 years was 95.3 +/- 3.4% and 84.3 +/- 3.8%, respectively (p < 0.05 by the generalized Wilcoxon test). The actuarial complication-free rate at 10 years was 89.4 +/- 4.3% and 67.9 +/- 4.8%, respectively (p < 0.05 by the generalized Wilcoxon test). No hemorrhagic complications were seen in the warfarin plus antiplatelet group. CONCLUSIONS The results strongly indicate the effectiveness and safety of combined warfarin plus antiplatelet treatment after St. Jude Medical valve replacement for mitral (plus aortic) valve disease.

Closure of Isolated Ventricular Septal Defect with Detachment of the Tricuspid Valve

Detachment of the septal leaflet of the tricuspid valve is an alternative technique for obtaining complete visualization of a perimembranous ventricular septal defect (VSD) in cases where the VSD is obscured by the chordae tendineae or a pouch formation of the septal leaflet. This method presents theoretical concerns because it has the potential for causing postoperative valvular insufficiency. We therefore evaluated valvular function in patients who underwent VSD closure with detachment of the tricuspid valve. In a consecutive series of 153 patients who underwent VSD closure using a transatrial approach, 13 had incision of the tricuspid valve. Follow‐up echocardiographic studies were performed on these patients at least 1 year following operation. There were no operative deaths. Color Doppler echocardiography revealed no residual shunt in any of these patients. Ten patients had no evidence of tricuspid stenosis or regurgitation. One patient had trivial tricuspid regurgitation. Moderate tricuspid regurgitation was observed in two patients of these, one patient was a small infant who had a VSD complicated by pulmonary hypertension. The other patient had a VSD with a mitral cleft, pulmonary hypertension, and Downs syndrome. The incised tricuspid valve was resus‐pended by solely running sutures. In conclusion, detachment of the tricuspid valve is a safe and useful method for adequate exposure of a VSD. However, this method should be avoided in patients with Downs syndrome and in small infants. Furthermore, repair of the incised valve should not be performed using only running sutures.

Limited vertical skin incision for median sternotomy

The cosmetic deformity of the vertical skin incision for median sternotomy was decreased by using a mechanical traction system to increase exposure at the superior margin of a shorter wound. The limited vertical skin incision did not impede technical surgical maneuvers and produced a scar that was more acceptable than submammary incision or right anterior thoracotomy. The limited skin incision is especially useful in young women with congenital heart disease.

Long-term results of the intracardiac repair of tetralogy of Fallot: a follow-up study conducted over more than 20 years on 100 consecutive operative survivors.

A long-term retrospective and follow-up study was conducted on patients with tetralogy of Fallot to evaluate survival rates and quality of life following surgery. Intracardiac repairs were performed on 132 patients at our institute between January, 1965, and July, 1971, among whom 100 consecutive operative survivors, being 54 males and 46 females, were followed for 20–25 years. Late deaths were confirmed in eight patients (8%) six of which (6%) were considered cardiac deaths. The 20- and 25-year survival rates were 93.7±2.5% and 90.9±3.6%, respectively. Reoperations were performed on six patients for residuae or sequelae without mortality or morbidity, and 90.4%±3.1% of the patients were free from late death or reoperation at 20 years and 83.9±5.3% at 25 years. Thirty-one of the 46 female patients were married and 28 had children. Forty-three live births were confirmed without any association of a congenital heart anomaly. Employment status was satisfactory in most of the patients, and 81%–89% of the patients in this series were considered to have a good quality of life. Less than half the patients had late symptoms, and all were related to cardiac arrhythmias. Late ventricular arrhythmias remain the major concern of the future, and therefore, the establishment of effective pre- and intraoperative management to prevent post-operative arrhythmias is essential.

Successful surgical treatment of incessant automatic atrial tachycardia with atrial aneurysm.

A 9-year-old boy with heart failure and long-term incessant atrial tachycardia mimicking dilated cardiomyopathy was treated surgically. Intraoperatively he was found to have atrial aneurysm, and the ectopic automatic focus was located at the base of it. Excision of the aneurysm including the focus without using cardiopulmonary bypass cured the tachycardia and heart failure.

Histologic findings of long-term cryolesions in a patient with ventricular tachycardia

This report describes cardiac morphologic alterations in a patient who died 14 months following cryoablation. Histologic examination of the long-term cryolesion revealed a homogeneous fibrous scar with surrounding sinusoid capillary proliferation. The border between the fibrosis and the normal myocardium was sharply defined. Cryothermia is an excellent technique for the surgical correction of arrhythmias because it provides sharply demarcated lesions which lack arrhythmogenic potential.

Total circular annuloplasty with absorbable suture for the repair of left atrioventricular valve regurgitation in atrioventricular septal defect

To obtain a better control of left atrioventricular valve regurgitation, we applied total circular annuloplasty with the use of absorbable sutures to 14 children with atrioventricular septal defect (six complete forms and eight incomplete forms). In the intraoperative period, a good coaptation of the leaflets was achieved and the regurgitation was minimized or disappeared. Follow-up studies with echocardiography for 13 survivors showed a gradual increase of annular size during the postoperative period. Ten patients of the survivor group (77%) maintained good valvular competency in a long-term period. Total circular annuloplasty is a simple and effective procedure to reduce the regurgitation and prevent the annular dilatation during the immediate postoperative period.

A comparative study of the effect of autologous platelet-rich plasma and fresh autologous whole blood on haemostasis after cardiac surgery

The effects of fresh autologous platelet-rich plasma and autologous whole blood on haemostasis after cardiopulmonary bypass were examined in adult cardiac surgery patients. Platelet count, adenosine diphosphate 10 microM maximum aggregation rate and clotting Factor VIII were greater in the platelet-rich plasma group (n = 11) than in the whole blood group (n = 8) after platelet-rich plasma or whole blood reinfusion. Blood loss after heparin neutralization was less in the platelet-rich plasma group than in the whole blood group. Blood loss from heparin neutralization to 12h after surgery was correlated with platelet count, fibrinogen and ADP aggregation rate. The number of patients who required homologous blood transfusion was less in the platelet-rich plasma group. In conclusion, the reinfusion of autologous platelet-rich plasma improves haemostasis after cardiopulmonary bypass, and may enable surgery to be performed without homologous blood transfusion.

Extracorporeal Membrane Oxygenation for Severe Heart Failure After Fontan Operation

A 10-year-old boy with tricuspid atresia and Glenn anastomosis underwent a modified Fontan operation. After the operation, the pressure in the inferior vena cava increased, leading to oliguria and ascites. After the creation of continuity between the superior vena cava and the inferior vena cava to reduce the pressure gradient, there remained an elevated right atrial pressure. Six days of extracorporeal membrane oxygenation effectively stabilized his hemodynamics and organ function and allowed an excellent outcome.

Closure of a ventricular septal defect in a patient with von Willebrand disease

Few reports of open heart surgery being performed in patients with von Willebrand disease (vWD) have been documented. We describe, herein the case of a 5-year-old girl with a ventricular septal defect (VSD) and vWD who underwent patch closure under cardiopulmonary bypass (CPB). The hematological parameters relating to vWD, namely, factor VIII, von Willebrand factor, and factor VIII-related antigen were monitored perioperatively. These laboratory findings were elevated after the termination of CPB, and consistently maintained within the normal range for 4 months postoperatively. The operation was successfully completed without the administration of factor VIII concentrates or homologous blood products.