Juro Wada

Long-Term Follow-up of Artificial Valves in Patients under 15 Years Old

Forty-nine artificial cardiac valves implanted in 44 patients less than 15 years old were reviewed. Out of 49 valves, 16 were mechanical and 33 were xenografts. Average follow-up was 2 years 5 months. Marked valvular stenosis developed in 11 out of the 33 xenografts, an incidence of 15% per patient-year. In patients with a xenograft valve, the incidence of sepsis was found to be 4% per patient-year and brain accidents, 4% per patient-year. In patients with mechanical valves, the incidence of stenosis was only 2% per patient-year and brain accidents, 2% per patient-year. There was no sepsis. From these follow-up results, mechanical valves seem to be superior to xenografts when used in patients less than 15 years old.

Clinical evaluation of total-body hyperthermia combined with anticancer chemotherapy for far-advanced miscellaneous cancer in Japan

One hundred sixty‐eight patients with miscellaneous far‐advanced cancer received a total of 444 extracorporeally induced total‐body hyperthermia (TRHT) treatments in seven Japanese hospitals. Overall, a regression of malignancy was observed in 39 of 132 evaluable patients (29.5%) and the most favorable results were obtained for patients with lung cancer. Irrespective of whether the tumors were primary or secondary lesions or recurrences, favorable results were obtained in patients whose tumors were in the lung, liver, lymph nodes, and soft tissue. No relationship was found between an objective response to TBHT and histologic types of the tumors. There was no clear relationship between an objective tumor response and the nature of the simultaneous chemotherapy during hyperthermia. Antitumor effects were not evaluable in 36 patients (21.4%). Of these 36 patients, 33 died before evaluation could be made; 24 died of various complications and 9 died of cachexia without complication. The mortality increased in proportion to the reduction of the performance status of patients before TBHT. These results indicate that TBHT should be used as therapy for patients whose tumors are in the lung, liver, lymph node, and soft tissue and then only on patients in generally good condition. Cancer 59:1101‐1106, 1987.

Cardiac Valve Replacement with Wada-Cutter Prosthesis

Abstract The Wada-Cutter cardiac valve prosthesis, a hingeless valve, was developed and used clinically in 106 patients in whom 42 aortic valve replacements, 48 mitral valve replacements, 5 tricuspid valve replacements, and 11 multiple valve replacements were done. A continuous knotless suture technique was invariably employed for fixation of the prosthesis regardless of the type of operation. Postoperatively there were 11 early and 17 late deaths, a cumulative mortality of 26.4%. Thromboembolic complications occurred in 9 patients following valve replacement. These consisted of thrombosed valve in 6 patients and embolization other than in the heart in 3 patients. Seventy-eight patients are presently alive, 68 of them in good condition.

Right Ventricular Aneurysm Following Open Cardiotomy for Correction of Tetralogy of Fallot

n recent years, the development of extracorporeal circulation has facilitated the surgical treatment of ventricular aneurysm, and I many successes have been reported. T h e majority of these reports have dealt with left ventricular aneurysms which developed following myocardial infarction. Aneurysms of the right ventricle by comparison are quite rare, only 14 having been previously reported (see Table 1). T h e following is a case report of right ventricular aneurysm which developed following open cardiotomy for correction of a congenital cardiac defect.

Two-stage treatment of ventricular septal defect with pulmonary hypertension.

entricular septa1 defect is the most common congenital cardiac lesion. The closure of simple ventricular defects has been perV formed with a very low mortality. In contrast, the results of surgical correction of ventricular defects with pulmonary hypertension have been generally unfavorable despite improved knowledge of cardiac physiology, surgical technique, and postoperative care. Muller and Dammann [13, 141 were the first successfully to employ constriction of the pulmonary artery as a palliative procedure for patients with a large left-to-right intracardiac shunt. In the era of complete correction of congenital cardiac defects under direct vision using heartlung bypass, pulmonary artery banding has been accepted by many cardiac surgeons for the treatment of infants with ventricular defects and pulmonary hypertension. We have employed a two-stage operation, with pulmonary artery banding as the first stage and closure of the ventricular defect as the second. We have used this operation not only for infants but also for older children to reduce the high surgical mortality from primary surgical closure [ 19-2 11. Since reports of second-stage correction of the ventricular defect and artifically constricted pulmonary artery have been scant [3, 5, 12, 161, we have reviewed our experience with the two-stage operation in treating infants and children with ventricular defects and pulmonary hypertension to define the role of this approach.

Unusual demand pacemaker arrhythmia due to partial recycling in the relative refractory period.

This report pretsents the electrocardiograms of a patient with a normally functioning lithium QRS‐inhibited pulse generalor that exhibited partial recycling with imappropri‐ately short escape intervols. The occurrence of partial recycling was time‐de‐pendent rather than voltage‐dependent, and was observed only when ORS com‐plexes fell within the relative refractory period of the pulse generator. This resutled in a complex arrhythmio simulating pulse generator maafunction. This ob‐servation re‐einphasizes the need for the physician to appreciute the technical char‐acteristics of pulse generotors to avoid Ihe unnecessary replacemsnl nf norniiilly funclioning units. (PACE VoJ. 2, March‐April, 1979.)

Long-term results of bypass grafts for atypical coarctation of the thoracic aorta.

Long-term results of bypass grafts for atypical coarctation of the thoracic aorta are presented. Six of the 13 patients with atypical coarctation were treated with long bypass from the descending thoracic aorta to the abdominal aorta. One of them had correction of right renal stenosis with a saphenous vein graft. Late clinical results of surgery (average follow-up time 4 years, 5 months and the longest over 10 years) were excellent, except for one patient who died 3 1/2 years postoperatively of acute abdomen. This experience suggests that atypical coarctation of the aorta can be treated satisfactorily by the long thoraco-abdominal bypass graft technique. If unilateral or bilateral renal artery stenosis is found simultaneously, renal revascularization is also necessary to obtain normalization of the blood pressures.

Placement of Left Atrial Pressure Monitoring Catheter: Use of an Elastic Surgical Suture

Placement of left atrial monitoring catheters during cardiac surgery may be complicated by hemorrhage following the removal of the catheters. The use of an elastic surgical suture made of polyurethane can prevent hemorrhage is used around inserted catheters, because the elastic suture automatically shrinks to close the catheter hole on the left atrial wall when the catheter is removed.

Automatic regulation of the cardiopulmonary bypass

We devised a new method and system for the automatic regulation of cardiopulmonary bypass. The system is planned so that it is regulated according to the alteration of venous pressure which is a reflection of venous return in total cardiopulmonary bypass. After many experimental studies, we have used this system in four clinical cases of cardiac surgery. The system functioned sufficiently well in the clinical cases. Under the control of this system, the central venous pressure was kept at a preset level and changed cyclically in the same manner as the respiratory change through the entire cardiopulmonary bypass period. A constant and adequate venous return through the entire cardiopulmonary bypass period was assumed to be the most important factor for the venous return-triggered pump oxygenator.

Heart preservation with metabolic inhibitor, hypothermia, and hyperbaric oxygenation

The effect of metabolic inhibitor, hypothermia (4°C) and hyperbaric oxygenation (3 atm) on prolonging survival of the canine anoxic heart has been evaluated. Donor hearts were obtained from small mongrel dogs by giving the pre-cooled perfusate of 2 per cent magnesium sulfate (MgSO4), 5 per cent low molecular weight dextran (LMWD) and 2 per cent glucose into the right atrium. Excised hearts were kept at 4°C in a hyperbaric chamber pressurized to 3 atm. After 18 to 48 hours the preserved hearts were transplanted to the neck of recipients by the methods of Marcus. The viability of the preserved hearts were evaluated with functional, biochemical and histologic parameters.Of 29 hearts preserved for 18 to 36 hours, 27 hearts returned to a strong coordinated beat and could maintain function for over 4 hours. Of 5 hearts preserved for 48 hours, 4 showed a coordinated ventricular beat, however, failed to maintain cardiac work over 4 hours. The hearts with 18 to 36 hours storage showed no significant abnormalities on myocardial metabolism and morphology as compared to the control group of the immediately transplanted hearts. The protective action of magnesium is probably related to a number of factors, including metabolic depression and stabilizing effect on membrane permeability of cells to potassium, which would tend to maintain a more normal membrane potential and sub-cellular particles. These studies indicate that viability of the mammalian anoxic hearts can be extended to 36 hours by the combined use of metabolic blockade, hypothermia and hyperbaria suggesting a practical approach to procurement and preservation of cadaver organs.