Tamotsu Yasuda

Surgical Treatment of Congenital Coronary Artery Fistulas: 27 Years' Experience and a Review of the Literature

Abstract Background and aim of the study: A congenital coronary artery fistula (CAF) is a relatively rare congenital anomaly and is defined as an abnormal direct communication between any coronary artery and any of the cardiac chambers. This article reviews our experience over the past 27 years, as well as other literature, and discusses the surgical indications and methods relating to CAF. Methods: From 1973, 25 patients aged from 2 to 69 years underwent surgical treatment for congenital CAF. Seventeen patients were diagnosed as isolated CAF. All patients under 19 years of age with isolated CAF were asymptomatic. Twenty fistulas originated from the left coronary artery and 9 from the right. The pulmonary artery was the most dominant drainage site. Four patients among the isolated CAF cases were surgically treated without a cardiopulmonary bypass. Results: All patients were discharged from hospital without any perioperative complications. Postoperative coronary angiography was done on all patients with only one slightly residual CAF flow. The average follow‐up time was 9.6 years and all patients were asymptomatic and doing well. Conclusions: Definitive surgical correction is safe and effective, with good results. Therefore, it should be considered even in asymptomatic patients because of the risk of future complications.

Near-infrared monitoring of myocardial oxygenation during intermittent warm blood cardioplegia

OBJECTIVE This study was performed to examine the ability of near-infrared spectroscopy to monitor tissue oxygenation in the cardioplegically arrested heart and to assess myocardial oxygen metabolism during intermittent warm blood cardioplegia. METHODS Using a three-wavelength near-infrared spectroscopy, we continuously measured myocardial tissue oxygen saturation and the tissue hemoglobin concentration during intermittent warm blood cardioplegia. Under normothermic cardiopulmonary bypass, 20 dogs received three 5-min periods of antegrade warm blood cardioplegia, interrupted by three 10-min episodes of ischemia in group 1 (n = 7), three 15-min episodes of ischemia in group 2 (n = 6), or three 20-min episodes of ischemia in group 3 (n = 7). RESULTS Myocardial oxygen saturation during beating and ventricular fibrillation was 80 +/- 1 and 59 +/- 1%, respectively. Myocardial oxygen saturation rapidly increased to 82 +/- 1% at blood cardioplegic infusion and decreased to 58 +/- 1% 3 min after cardioplegic interruption. The time required to reach the peak oxygen saturation level decreased significantly at the second and third infusions compared to the first infusion in group 1, whereas the time increased significantly at the third infusion in groups 2 and 3. The slower rate of increase in oxygen saturation suggested reduced coronary vasodilator reserve due to microvascular abnormalities. Reperfusion ventricular fibrillation occurred in none of group 1, one of group 2 and three of group 3. CONCLUSIONS Near-infrared spectroscopy is a useful method of continuously monitoring myocardial oxygenation and ischemia during warm heart surgery. Episodes of ischemia longer than 10 min during warm blood cardioplegia resulted in less-than-optimal myocardial preservation and should be avoided.

Myocardial Oxygenation During Terminal Warm Blood Cardioplegia

BACKGROUND Terminal warm blood cardioplegia accelerates myocardial metabolic recovery. The process of myocardial oxygenation during terminal warm blood cardioplegia and its optimal administration are not clear. METHODS We measured the myocardial tissue oxygen saturation (SO2) during reperfusion using near-infrared spectroscopy. Twenty-four dogs underwent 1 hour of ischemic arrest with cold crystalloid cardioplegia. They were then divided into four equal groups. Group 1 dogs received normal blood reperfusion. The other dogs received 15 mL/kg of terminal warm blood cardioplegia at 80 mm Hg in group 2 or at 60 mm Hg in group 3, and 30 mL/kg of cardioplegia at 60 mm Hg in group 4, followed by blood reperfusion. RESULTS In group 1, the SO2 increased gradually during the early reperfusion and decreased transiently during the late reperfusion. In group 2, the SO2 increased rapidly but it decreased transiently during blood reperfusion. In groups 3 and 4, the SO2 increased rapidly and remained at high levels during the blood reperfusion. Reperfusion ventricular fibrillation occurred along with a SO2 decrease only in groups 1 and 2. The postischemic troponin-T levels of groups 3 and 4 were lower than that of group 1. The functional recovery in group 4 was better than those in the other three groups. CONCLUSIONS Terminal warm blood cardioplegia accelerates the early SO2 increase and abolishes the SO2 decrease during subsequent reperfusion and reduces the incidence of reperfusion arrhythmia, suggesting that it ameliorates reperfusion injury and consequently improves postischemic functional recovery.

Aortic valve replacement for the calcified ascending aorta in homozygous familial hypercholesterolemia.

A 72-year-old woman who had been diagnosed as homozygous familial hypercholesterolemia was admitted for chest discomfort. Computed tomography and cardiac catheterization revealed severe calcification of the aortic root and a high grade stenosis of the proximal right coronary artery. Aortic valve replacement concomitant with coronary artery bypass was done using temporary hypothermic circulatory arrest. This is preferred method when dealing the calcified aorta.

Ultra-short-acting cardioselective beta-blockade attenuates postischemic cardiac dysfunction in the isolated rat heart

OBJECTIVES We sought to test the effectiveness of ultra-short-acting cardioselective beta-blockade, landiolol hydrochloride, for warm heart surgery. METHODS The isolated perfused rat heart preparation was used. After preischemic measurement of cardiac function, 3 min of coronary infusion of crystalloid cardioplegic solution (37 degrees C) with landiolol hydrochloride of various concentrations (1, 2.5, 5, and 10 mmol/l) or without it (control group) was performed, followed by 30 min of warm ischemic arrest. Finally, postischemic function was measured. RESULTS The percentage recoveries of heart rate in hearts receiving 0, 1, 2.5, 5, and 10 mmol/l landiolol hydrochloride were 89.4+/-3.4%, 90.9+/-1.7%, 89.6+/-1.8%, 83.4+/-3.3%, and 74.3+/-1.9% (P<0.05 vs. 0, 1, and 2.5 mmol/l groups), respectively. The percentage recoveries of aortic flow were 55.6+/-3.1%, 62.8+/-3.3%, 75.0+/-4.2% (P<0.05 vs. 0 and 10 mmol/l groups), 65.3+/-5.3%, and 51.6+/-4.0%, respectively. Similar recovery profiles were observed with the first derivative of the rise in aortic pressure, stroke volume and stroke work. The total amount of coronary effluent in the hearts receiving 5 or 10 mmol/l was lower than in the other groups. CONCLUSIONS Landiolol hydrochloride has the potential to enhance postischemic cardiac function after the warm cardioplegic arrest. The optimal concentration for maximum postischemic functional recovery was 2.5 mmol/l, and recoveries of aortic flow and heart rate decreased in hearts receiving 5 mmol/l or more.

Coronary artery bypass surgery with arterial grafts in familial hypercholesterolemia

OBJECTIVE Familial hypercholesterolemia is a dominantly inherited disorder caused by mutations at the locus for the low-density lipoprotein receptor and is frequently associated with premature coronary artery disease. This study was performed to determine whether arterial grafting was associated with long-term benefits for patients with familial hypercholesterolemia. METHODS During the past 18 years, 101 patients with heterozygous familial hypercholesterolemia underwent primary coronary artery bypass grafting, with one hospital death. Group 1 patients (n = 31) received only saphenous vein grafts. Group 2A patients (n = 47) received one internal thoracic artery graft and supplemental vein grafts, and group 2B patients (n = 23) had multiple arterial grafts. After operation, all patients received diet therapy and intensive cholesterol-lowering drug therapy. Thirteen patients received low-density lipoprotein apheresis. RESULTS During a mean follow-up period of 95 months, 8 patients died, 9 underwent reoperation, and 12 received catheter intervention. The overall survival was 82% (95% confidence limits, 65%-97%) at 18 years after operation. The survival in group 2 was higher than that found in group 1 (P =.01). The overall freedom from major cardiac events (myocardial infarction, cardiac death, reoperation, and catheter intervention) was 57% (95% confidence limits, 40%-74%) at 16 years after operation. The freedom from reoperation in group 2 was higher than that found in group 1 (P =.03). There was no difference in the survival or freedom from major cardiac events between groups 2A and 2B. CONCLUSION Arterial grafting improved the long-term freedom from reoperation in patients with familial hypercholesterolemia. Additional benefit of multiple arterial grafting could not be identified.

Leiomyosarcoma of the thoracic aorta

This case involves a patient with aortic leiomyosarcoma. A patient clinically suspected of type IIIa dissecting aortic aneurysm underwent surgery. The descending thoracic aorta was found to be filled with a soft, yellow tumor and was replaced with a woven Dacron graft. Microscopy of the surgical specimen revealed large, atypical spindle cells with numerous mitoses in bundles intersecting at 90 degrees, suggesting leiomyosarcoma. This diagnosis was confirmed immunohistochemical study. The postoperative course was uneventful and the patient was discharged on postoperative day 40; however, the patient developed bronchopneumonia due to malignant pleuritis 3 months postoperatively and died on postoperative day 103.

Double aneurysms of arch and descending aorta associated with right aortic arch

We report a case of a 69-year-old man in whom double aortic aneurysms of the arch and descending aorta with a right aortic arch and mirror-image branching were diagnosed by three-dimensional computed tomography and aortography. These techniques are useful to assess the exact anatomy of the lesion and branches of the arch. The patient was successfully treated by a two-stage operation consisting of aortic arch replacement followed by descending aorta replacement.

A Multipurpose Arterial Graft Holder for Coronary Artery Bypass Grafting

A multipurpose arterial graft holder designed for use during coronary artery bypass grafting is described. This new holder is atraumatic and holds the arterial grafts and saphenous vein graft securely during anastomosis. The use of this instrument facilitates the use of multiple arterial grafts for coronary artery bypass grafting.

Ultrastructural assessment of the myocardium receiving intermittent antegrade warm blood cardioplegia.

Ultrastructural changes in the myocardium during intermittent warm blood cardioplegia were studied in 12 dogs. During cardiopulmonary bypass, dogs received three 5-minute periods of warm blood cardioplegia, interrupted by three 10-minute episodes of ischemia in group A or three 20-minute episodes of ischemia in group B. Biopsy specimens were taken from the right ventricle before each cardioplegic infusion and at the end of the aortic cross-clamp period to analyze ultrastructural changes. Functional recovery was measured after cardiopulmonary bypass. Mild and principally reversible ultrastructural changes were observed in group A. In group B, moderate ultrastructural changes were observed, and these changes suggested cumulative ischemic injury. Functional recovery was good in group A, but significantly deteriorated in group B. We concluded that three 10-minute interruptions of warm blood cardioplegia cause mild ultrastructural changes and seem to be safe, but three 20-minute interruptions cause cumulative ischemic injury in normal dog hearts.