Hirofumi Ide

The effect of cardiopulmonary bypass on T cells and their subpopulations.

To investigate the effect of cardiopulmonary bypass (CPB) on T cells, lymphocyte subsets of peripheral blood and lymphoid organs were monitored during and after open-heart surgery (Group 1). As a control, lymphocyte subsets of peripheral blood were measured in patients undergoing thoracovascular operations without CPB (Group 2). In Group 1, analysis of each subset-to-total lymphocyte ratio revealed that observed lymphocytopenia in the early postoperative days was mainly the result of T cell reduction, and that the decrease of helper/inducer T cells contributed to this decrease. In contrast, no significant fluctuation of any lymphocyte subpopulation ratio was observed in Group 2. Analysis of lymphocyte subpopulation ratios in lymphoid organs showed that reciprocal changes of T cells and their subsets were observed in the bone marrow, thus indicating that the redistribution of T cells (especially of helper/inducer cells) seems to occur between peripheral blood and bone marrow in Group 1. Furthermore, there was no relationship between serum cortisol levels and the changes in lymphocyte subset ratios in Group 1 patients.

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.

Off-pump coronary artery bypass for a heparin-allergic patient

A 46-year-old man with no history of drug allergy developed acute myocardial infarction. Coronary angiographic findings revealed triple vessel disease. Serum hepatic enzymes were elevated due to heparin administered to control infarction, and an allergic reaction developed exclusively due to heparin. To avoid heparin use, we adopted heparin-free off-pump coronary artery bypass grafting through median sternotomy. The systemic anticoagulant agent argatroban was administered to maintain active clotting time over 200 seconds. The left internal thoracic artery was anastomosed to the left anterior descending artery, the radial artery to the diagonal branch, and the right gastroepiploic artery to the right coronary artery. Patency was confirmed by postoperative coronary angiography. No complications were noted. For patients with heparin allergy, off-pump coronary artery bypass grafting is a useful maneuver, because it can be conducted using anticoagulant agents other than heparin.

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.

The Role of Leukocyte Depletion by in Vivo Use of Leukocyte Filter in Lung Preservation After Warm Ischemia

The oxygen metabolites of leukocytes have been implicated as playing the central role in reperfusion injury of preserved lung for transplantation. Furthermore, it is still unknown how leukotrienes take part in this process. Twelve mongrel dogs were used, divided into two groups. In group A, left thoracotomy and hilar stripping of the left lung was performed under anesthesia. During warm ischemia (two hours) and reperfusion (two hours), a filter was used three times between the femoral artery and vein, and quantitative in vivo blood filtration was performed. In group B, warm ischemia and reperfusion was done in the same fashion without filtration. As for tissue free radical assay, lipid peroxidation products were measured by means of thiobarbituric acid. Tissue leukotriene B4 and C4 levels were measured by radio immunoassay. In addition, peripheral blood count and tissue wet/dry ratio were analyzed. Significant leukocyte depletion of peripheral blood with leukocyte efflux from reperfused lung was observed in group A. Significant increase of tissue malondialdehyde (MDA) titers after reperfusion was observed in group B, whereas no significant fluctuation of tissue MDA titers was noted in group A. Concerning leukotriene B4 and C4, no significant increase was observed in either group. Tissue damage estimated by lung wet/dry ratio was considered to be controlled in group A compared with group B. Thus, the authors conclude that in vivo use of a leukocyte filter is efficient in removal of peripheral blood leukocytes and in preservation of reperfused lung after warm ischemia and that oxygen metabolities of leukocytes are considered to play a role in tissue damage in this process.

A New Antithrombogenic Coating Material — Fluorine-Acryl-Styrene-Urethane Silicone Graft-Block Copolymer — for a Circulatory Assist Device

To assess the effectiveness of a fluorine-acryl-styrene-urethane-silicone (FASUS) graft-block copolymer (DIA Medical Supply, Chiba, Japan) as a new antithrombogenic coating material, we evaluated it in a veno-arterial bypass (VAB) circuit in a canine model. Twelve dogs, divided into two groups, underwent femoro-femoral VAB without an oxygenator for 6 h at a mean flow of 500ml/min. In the control group (control, n = 6), non-coated polyvinyl chloride tubes and nylon cannulas were used. In the FASUS-coating group (coated, n = 6), all tubing materials and cannulas were coated with a FASUS copolymer. Heparin (0.5 mg/kg) was administered only initially. After the VAB was completed we examined macroscopic clots on the material surfaces, and we examined microthrombus formation and platelet morphology by, using a scanning electron microscope (SEM), to evaluate thrombogenicity. Both macroscopic and microscopic examinations, showed that all tubing materials in the control group had major clots. By contrast, no clots were observed in any portions of the entire circuits of the coated group. SEM examinations revealed thick layers of platelet aggregation and fibrin sheets that had firmly adhered to the uncoated surfaces, whereas in the coated group, morphologic platelet changes were slight. These data suggest that a FASUS polymer coating over the entire VAB circuit is effective for preventing thrombus formation.

Reoperative coronary artery bypass via left thoracotomy

The patient was a 49-year-old woman. When she was 39 years old, she underwent coronary artery bypass grafting (left internal thoracic artery to left anterior descending artery, saphenous vein graft to first diagonal branch). At the age 48, she had effort angina. On coronary angiography, triple-vessel disease was found, and she was treated conservatively. Progression of the disease was confirmed with detection of the left circumflex artery associated with jeopardized collateral to the right coronary artery showing total occlusion. The patient underwent reoperation. Since the left internal thoracic artery was patent despite occlusion of the saphenous vein graft, the approach of left thoracotomy was employed. Under cardiopulmonary bypass with ventricular fibrillation and left vent through left atrial appendage, the right radial artery was anastomosed to the left circumflex artery from the descending thoracic aorta, and the right gastroepiploic artery was anastomosed to the right coronary artery (4AV branch). Patency of the bypass was confirmed postoperatively. We consider this operative technique was especially useful for reoperation in cases of a patent internal thoracic artery in which left thoracotomy can be conducted safely.

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.

Two cases of surgical treatment of recrudescent Stanford type A dissection after early thrombogenic closure without intimal tear

We reported two cases of thrombosed, Stanford A type acute aortic dissection, initially without intimal tear, later operated upon because of recrudescence. They admitted to our hospital with the symptoms of aortic dissection. Early examination of computed tomography and angiography demonstrated thrombosed type A aortic dissection showing a normal aortic figure, although accompanied by pericardial effusion, that was drainaged. Under strict BP control, however, repeat CT examination revealed recrudescent dissection of ascending aorta, making dissecting aneurysms. Graft replacement of ascending aorta was performed, on the 55th and 153th day after admission, and they were discharged.

Operations for Descending Thoracic Aortic Aneurysms Utilizing the Antithrombotic Cardiopulmonary Bypass.

1993年9月より1996年4月までに胸部下行大動脈を主体とした動脈瘤15例に対し, 左開胸による抗血栓処理部分体外循環法を用いた手術を行った. 疾患内訳は, 真性動脈瘤 (うち, 破裂例2例) 10例, 慢性解離性大動脈瘤4例, 大動脈縮窄症を伴う大動脈瘤1例で, 実施した手術は人工血管置換術12例. パッチ閉鎖術3例であった. 手術死亡は1例で, 虚血性心疾患を有する真性下行大動脈瘤破裂, ショックにて緊急手術を行い, 術後, 心筋梗塞によると考えられる急性心不全で失った. その他の14症例では本補助手段に起因すると考えられる血栓塞栓症等の合併症や術後諸臓器不全, 出血性合併症もなく, 全例軽快退院した. 今回の臨床的検討により, 本法は, 胸部下行大動脈手術の補助手段として, 安全で有効な方法であると考えられた.