Akihiro Mizuhara

Left ventricular end-systolic volume index in patients with ischemic cardiomyopathy predicts postoperative ventricular function

BACKGROUND We investigated the usefulness of the preoperative left ventricular end-systolic volume index (LVESVI) as a predictor of postoperative ventricular function. METHODS We retrospectively reviewed the records of 310 patients who underwent coronary artery bypass grafting and identified 20 patients with ischemic cardiomyopathy with a preoperative ejection fraction less than 0.30. We determined the preoperative and postoperative ejection fraction, LVESVI, and left ventricular enddiastolic volume index using biplane left cineventriculography. Patients were divided into groups depending on whether their preoperative LVESVI was less than 100 mL/m2 (group A, n = 10) or greater than 100 mL/m2 (group B, n = 10). RESULTS The mean ejection fraction increased significantly after coronary artery bypass grafting in group A from 0.25 +/- 0.05 to 0.40 +/- 0.09 (p < 0.01), but did not change significantly in group B (0.26 +/- 0.05 versus 0.23 +/- 0.06). The mean LVESVI decreased significantly in group A from 83.2 +/- 13.7 to 61.7 +/- 20.4 mL/m2 after operation (p < 0.05), but did not change significantly in group B (124.7 +/- 21.0 versus 121.5 +/- 37.6 mL/m2). In group B, 4 patients had signs of congestive heart failure during the follow-up period and had to be rehospitalized. CONCLUSIONS The mean ejection fraction improved significantly after coronary artery bypass grafting in patients with a preoperative LVESVI less than 100 mL/m2, despite the presence of a global left ventricular ejection fraction less than 0.30. Our results suggest that the preoperative LVESVI predicts the postoperative status and left ventricular function in patients with ischemic cardiomyopathy.

Evaluation of the pulsatility of a new pulsatile left ventricular assist device--the integrated cardioassist catheter--in dogs.

A new pulsatile left ventricle-femoral artery bypass system (integrated cardioassist catheter system) has been developed for rapid, percutaneous insertion as a left ventricular assist device. Previous experiments revealed its superiority over the intraaortic balloon pump system in maintaining the peripheral circulation and in improving myocardial blood flow and afterload. Our objective was to determine whether the pulsatility of left ventricular bypass of this system would be preferable for maintaining the peripheral circulation and managing the ischemic myocardium as compared with nonpulsatile left ventricular bypass. Ten dogs with profound heart failure were supported by this system. Their hemodynamic status and myocardial blood flow were measured under control, nonpulsatile left ventricular bypass, or synchronous pulsatile left ventricular bypass. Significant differences between the nonpulsatile bypass group and the pulsatile bypass group were observed in the mean increase in aortic pressure (3.5% versus 22.2%, respectively; p < 0.001), total cardiac output (13.0% versus 21.7%; p = 0.004), and myocardial blood flow (9.5% versus 21.8%; p < 0.001). No differences were found between groups in the decrease in left atrial pressure (-20.2% versus -20.2%; p > 0.05). The ratio of diastolic time index/tension time index was shown to be improved significantly in the pulsatile bypass group compared with that of control and nonpulsatile bypass groups (p < 0.001). Thus, the pulsatility of the integrated cardioassist catheter system may support the peripheral circulation and improve the myocardial blood flow and oxygen supply/demand ratio.

Proinflammatory Cytokine Levels in Patients Undergoing Cardiopulmonary Bypass: Does Lung Reperfusion Influence the Release of Cytokines?

Proinflammatory cytokines have been implicated in mediating tissue injury after cardiopulmonary bypass. Causative factors of inflammatory response after cardiopulmonary bypass include contact of the blood with the extracorporeal circuit and heart-lung reperfusion injury when discontinuing bypass. To evaluate proinflammatory cytokine release during cardiopulmonary bypass, plasma levels of interleukin-6, 8, and monocyte chemoattractant factor were measured in the radial artery (for systemic blood) and left atrium before and after cardiopulmonary bypass. A total of 13 patients were studied, with no deaths or complications. In both radial artery and left atrium, interleukin-6, 8, and monocyte chemoattractant factor rose significantly after cardiopulmonary bypass (p < 0.05 versus before cardiopulmonary bypass). These changes may have been caused by removal of the aortic cross clamp and recommencement of artificial ventilation, which result in reperfusion of the pulmonary capillary beds. There were no differences in cytokine levels after cardiopulmonary bypass in the radial artery and left atrium. This result suggested that lung reperfusion injury after cardiopulmonary bypass may not be the major causative factor of the release of proinflammatory cytokines.

Successful repair of combined ventricular septal rupture and free wall rupture

The successful surgical repair of combined ventricular septal perforation and free wall rupture (double rupture) after inferior myocardial infarction is reported. Extensive inferior wall infarctectomy was performed, and both defects were closed with a prosthetic patch, using a modification of the technique developed by Daggett. The patient was alive and well 1 year after operation.

Acute Occlusion of the Descending Thoracic Aorta: Report of a Case

This report describes the unusual case of an acute occlusion of the descending thoracic aorta in a 52-year-old woman. The patient underwent successful extraanatomical bypass with intraoperative hemodialysis.

DeBakey-Type IlIb Aortic Dissection with Multiple Aneurysmal Changes of the Peripheral Arteries A Case Report

A forty-four-year-old woman presented with a DeBakey-type IlIb dissecting aneurysm, multiple aneurysmal dilatation of the coronary arteries, and a “string-of-beads” appearance of the peripheral arteries (due to cystic medial necrosis and intimal hyperplasia). Upon assessment of her family history and multiple vascular involvement secondary to cystic medial necrosis, an incomplete Marfans syndrome was suggested. This rare case of multiple aneurysmal changes to the great and peripheral arteries is presented with special reference to the radiographic and morphologic manifestations.

Inferior Vena Caval Tumor Thrombus from Renal Angiomyolipoma A Case Report

The authors report a case of bilateral renal angiomyolipoma with tumor thrombus from the right kidney extending to the inferior vena cava. Right nephrectomy and total thrombectomy were performed. Vena caval tumor thrombus rarely occurs in patients with angiomyolipomas. To their knowledge, only 6 cases have been reported in the literature.

The Prevention and Management of Postoperative Mediastinitis and the Infection Promoting Potential of Bone Wax.

胸骨正中切開のアプローチによる心臓外科手術338例のうち, 初期の233例には胸骨切開時に骨ロウを使用したが, 7例 (3.0%) の縦隔炎が発生した. 7例のうち6例の縦隔炎に対しては, 創部開放洗浄ののちに大網を充填するという治療を行った. これら6例において全例とも縦隔炎は治癒したが, 1例のみ脳梗塞, 肺炎のために失った. この反省から, その後の105例には骨ロウを使用せずアルゴンビームコアギュレーターにて止血を行ったところ, 縦隔炎の発生は皆無 (0%) となった. 骨ロウは, 縦隔炎の発生に大きく関与している可能性があり, その使用については再検討が必要である. 胸骨切離面の止血にはアルゴンビームコアギュレーターを使用したが, 術中出血量, 術後出血再開胸の頻度などに差は認められず, 有用であった.

A CASE OF AXILLARY ARTERIAL ANEURYSM ASSOSIATED WITH BUERGER'S DISEASE

A 62-year-old man was admitted to the hospital because of a right axillary pulsatile mass and intermittent claudication of the left lower extremity and right arm. Since his right lower extremity had been amputated above the knee for aggravated Buergers disease, he was obliged to walk on crutch when his body weight was rested on the right axilla. The large pulsatile mass, 60×30mm in size, was diagnosed as the axillary arterial aneurysm by angiographic study. The aneurysm was excised and replaced by a saphenous vein graft. Histological examination of the excised specimen disclosed no specific findings to Buergers disease. Postoperative course was uneventful and the patient recovered his daily activities. The axillary arterial aneurysm associated with Buergers disease is quite rare. A probable cause of this aneurysm can be thought that chronic blunt trauma to the right axilla by the crutch may affect the regional weakened arterial wall due to Buergers disease.