[Experience of coronary artery bypass grafting with internal thoracic artery].

Between March 1990 and May 1991, twenty-nine patients underwent coronary artery bypass grafting. The mean number of grafts was 2.7 +/- 0.9 grafts per patient. 28 patients (96.6% of all cases) underwent CABG with the internal thoracic arteries. The perioperative mortality was 3.4% (1/29 cases). The postoperative coronary angiography at one month revealed that the early patency of total grafts, of internal thoracic artery grafts and of saphenous vein grafts were 96.7% (58/60 grafts), 100% (29/29 grafts), 93.5% (29/31 grafts) respectively. The early patency of internal thoracic artery graft was better than of saphenous vein graft.

Effects of coronary artery bypass surgery on regions showing persistent defects in thallium myocardial images.

The indications for revascularization surgery and its effects on myocardial regions showing persistent defects in thallium myocardial images are controversial. The effects of aortocoronary bypass surgery on myocardial perfusion and wall motion in the regions with persistent defects were evaluated in 47 patients with thallium-201 single photon emission computed tomography and left ventriculography. In areas showing persistent thallium defects preoperatively the rate of improvement of perfusion was only 24% by postoperative thallium imaging, and 57% by wall motion analysis. These results were significantly inferior to those of regions with transient defects, which were 84% and 82%, respectively. A persistent defect may not be a definitive marker of a non-viable scar, but the results of surgery on such regions were unsatisfactory. It is concluded, therefore, that revascuralization surgery in regions with persistent defects is not always recommended and that the indications for surgery should be individually determined with operative risk balanced against benefits.

[Severe postoperative pulmonary hypertensive crisis in a case of ventricular septal defect with Down's syndrome].

We encountered the episode of severe postoperative pulmonary hypertensive crisis in a case of ventricular septal defect with Down's syndrome. A 1 year 11 month old female with ventricular septal defect and pulmonary hypertension underwent open heart surgery. On the operative day after tracheal suction she experienced bradycardia, hypotension and pulmonary hypertension followed by shock condition. In spite of vigorous medical therapy clinical aspects were not improved. But only blood transfusion directly into the left atrium and administration of tolazoline hydrochlorides through pulmonary artery were very effective to improvement of hemodynamics and reduction of pulmonary hypertension. Moreover, after this episode pulmonary artery pressure showed elevation at the tracheal suction and the weaning from the respirator. We discussed the cause and treatment of postoperative pulmonary hypertensive crisis.

Isolated interruption of the aortic arch.

We report a case of a 4-year-old girl with interruption of the aortic arch without a patent ductus arteriosus or intracardiac shunts. The anomaly was successfully corrected with the use of a 14 mm Dacron prosthetic graft to bypass the interrupted segment. The postoperative course was uneventful.

Common peroneal nerve palsy. A complication of coronary artery bypass grafting surgery.

Two cases of common peroneal nerve palsy after coronary artery bypass grafting surgery are described and the possible causative mechanisms are discussed.

Myocardial positron tomography with N-13 ammonia in assessment of aortocoronary bypass surgery.

A total of 20 patients were examined at rest and during stress with N-13-ammonia myocardial positron emission tomography (PET) before and after aortocoronary bypass surgery in an attempt to evaluate the effect of surgery on myocardial perfusion and to predict the graft status. The PET images were divided into anterior, septal, apical, lateral and posteroinferior segments for analysis and were evaluated as "normal" (no perfusion defects during stress and at rest), "ischemia" (stress-induced defects) and "fibrosis" (persistent defects both at rest and during stress). Approximately 90% of the segments which were ischemic before surgery became normal after surgery. Thus, ischemic changes are highly reversible, and the vessels perfusing these ischemic areas are most suitable for bypass surgery. However, most of the persistent defects failed to respond to revascularization surgery and, hence, represented irreversibly damaged myocardium. In predicting graft status, graft patency could be demonstrated by normal perfusion in postoperative images (p less than 0.01) or by improved perfusion when pre- and postoperative images were compared (p less than 0.01). However, graft occlusion could not be predicted reliably. This study demonstrated that PET with N-13 ammonia was useful in the assessment of the effects of aortocoronary bypass surgery. However, this technique was not significantly superior to thallium-201 single-photon emission computed tomography for only qualitative analysis.

Clinical application of left ventricular assist devices.

In Japan, 32 patients have had application of monoventricular and biventricular assist devices during the past three years. Five of the 32 patients treated by the Fall of 1986 have successfully achieved long-term survival. In this paper we describe our experience with the Tomasu and Pierce VAD in a total of four and two patients, respectively. Four of the six patients could be successfully weaned from the VAD and two of them were long-term survivors. Nonsynchronizing pumping of the VADs was effective, as well as synchronizing pumping. Anticoagulant therapy is highly recommended during the use of the VAD although there was no significant incidence of thromboembolism or thrombus in the devices in this clinical series.