川人 宏次

A new antithrombogenic material was studied, fluorine-acryl-styrene-urethane-silicone (FASUS) copolymer, the theoretical basis of which attributed to its hydrophilic and hydrophobic microdomain structure. In this series of experiments, the blood compatibility of this copolymer was evaluated in vitro and ex vivo. For the in vitro evaluation, a whole blood clotting test and the microsphere column test were performed. For the ex vivo evaluation, two series of shunt tests in rabbits were performed, one was the arterioartery (A-A) shunt model, and the other was the arteriovenous (A-V) shunt model. The antithrombogenicity was assessed by measuring the shunt obstructive time in the A-A shunt experiment. The A-V shunt experiment was assessed by measuring the circulating platelet counts, platelet aggregability, activated partial thromboplastin time (APTT), and prothrombin time (PT). In the whole blood clotting test, FASUS revealed the significantly longer blood clotting time than that of the control glass tubings (19.7 +/- 1.0 versus 6.5 +/- 0.7 min, p < 0.001). In the microsphere column test, the coated group had a 30% reduction of the platelet number in the eluted blood in contrast with a marked decrease of 70% in the control group (p < 0.05). In the ex vivo A-A shunt experiment, the occlusion time for the FASUS-coated group was significantly longer than that of the control (109.7 +/- 17.3 versus 3.0 +/- 0.4 min, p < 0.05). The A-V shunt experiment showed that the FASUS copolymer suppressed the decrease in platelet counts and tended to improve prolonged APTT compared with that of the control. Clinically, in 25 patients, we placed coated FASUS copolymer into the cannulas for use in percutaneous cardiopulmonary support (PCPS) procedures. There was no evidence of thrombus on the blood contacting surface and no thromboembolism in major organs clinically or upon postmortem examination. In summary, this new copolymer may be effective in preventing thrombus formation in vitro, ex vivo, and in clinical situations.

Cardiac operations with cardiopulmonary bypass cause a systemic inflammatory response. Neutrophils and monocytes-macrophages play an important role in triggering the initiation of the inflammatory response. Recently, some kinds of cytokines that are powerful leukocyte chemotactic factors have been characterized concerning an inflammatory response: interleukin-8 has a potent chemoattractant activity for neutrophils, and monocyte chemoattractant factor has monocyte-macrophage chemotactic activity, To investigate the possible roles of the cytokines in the inflammatory response in cardiopulmonary bypass, 12 adult patients undergoing cardiopulmonary bypass were studied for measurement of interleukin-8 and monocyte chemoattractant factor, Systemic blood was collected before cardiopulmonary bypass, at the end of cardiopulmonary bypass, and at 3, 12, 24, and 48 hours after cardiopulmonary bypass from the patients' radial arteries, Significant increases in levels of interleukin-8 and monocyte chemoattractant factor were detected with a peak level at 3 hours after bypass compared with levels before cardiopulmonary bypass (p < 0.05). This study demonstrated that interleukin-8 and monocyte chemoattractant factor are released into the circulation after adult hypothermic cardiopulmonary bypass and reach a maximum level 3 hours after bypass.

Open proximal anastomosis with hypothermic circulatory arrest was used for the replacement of descending aorta in 7 patients. Left heart bypass and partial cardiopulmonary bypass with anti-thrombotic system were also used in 7 and 6 patients, respectively. These three systems were compared with each other in terms of the results of treatment and clinical usefulness. One patient with left heart bypass and two patients with partial cardiopulmonary bypass died due to the thrombosis by the aortic clamp and the aortic dissection by the trouble of anastomosis. One patient with open anastomosis died due to LOS despite of uneventful anastomosis. Open proximal anastomosis may be useful for the patient with the aortic pathology extended to the distal aortic arch. The patient with aortic dissection in the descending aorta may be also a good candidate for this method.

A forty-four-year-old woman presented with a DeBakey-type IIIb 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 Marfan's 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.

To overcome the hemorrhagic complications that may occur during extracorporeal circulatory support for post cardiotomy shock patients, a heparinized circuit was introduced into the percutaneous cardiopulmonary support system and decreased systemically administered heparin during bypass. Heparin coated percutaneous cardiopulmonary support with low dose systemic heparinization was instituted in 13 patients (6 men and 7 women, mean age 62.2 ± 8.5 years) who experienced circulatory collapse after cardiac surgery. Of the 13 patients, 9 could not be weaned from cardiopulmonary bypass and 4 had circulatory collapse in the operating room or in the intensive care unit. The duration of support ranged from 1 to 66 hr (mean 27.4 ± 26.7), and the flow rate ranged from 1 to 3 L/min (2.2 ± 0.5). An activated coagulation time of about 150 sec was maintained with or without minimal systematically administered heparin. Of the patients cannulated, 77% (10 of 13) were successfully weaned from percutaneous cardiopulmonary support and 39% (5 to 13) were long-term survivors. The causes of death were sepsis in three, progressive heart failure in three, lower leg ischemia in one, and vital infection in one. From the results of clinical or post mortem examinations, there was no massive bleeding or evidence of thromboembolism in the major organs. From observations made within 12 hr of initiation of percutaneous cardiopulmonary support, there was no significant decrease in the number of platelets, but platelet count had significantly decreased 24 hr after initiation. The authors' experience indicates that heparin coated percutaneous cardiopulmonary support with low dose systemic heparinization is beneficial for circulatory assist in circulatory collapse after cardiac surgery because of its simplicity and antithrombogenicity, which thus avoids the risk of bleeding complications.

通常の心肺蘇生では心拍再開が得られなかった心肺停止例11例 (男性5例, 女性6例, 平均年齢59.3歳) に対して, 緊急経皮的心肺補助システム (PCPS) による心肺蘇生を行った. 対象は手術への bridge とした症例が2例, PTCAへの bridge とした症例が2例, 蘇生後も心肺補助を継続した症例が7例であった. 循環補助時間は10.5±9.1 (mean±S. D.)時間, 補助流量は2.5±0.7l/分, 心停止からPCPS開始までは5分から70分, 平均24.9分であった. 回路はヘパリンコーティングを主とした抗血栓性材料でコーティングし, activated coagulation time を約150秒で維持した. これら10例中30日以内の早期生存は6例 (54.5%), 長期生存は4例 (36.4%) であった. 合併症として脳神経後遺症2例, 縦隔炎1例, 人工弁感染1例, 敗血症1例が発生した. PCPSによる救急蘇生は, 慢性期の脳合併症, 感染が問題となるが, 従来の心肺蘇生に反応しない心肺停止例を救命できる可能性が高く, 新しい心肺蘇生法としての有用性が示唆された.

症例は67歳,女性.右冠動脈(RCA) #1 100%,左冠動脈(LAD) #7 90%, #9-1 75%,回旋枝(LCX) #14 100%の病変を有する陳旧性心筋梗塞,狭心症に対して3枝バイパスを施行した.右心不全のため人工心肺から離脱不可能となり,静動脈バイパス(VAB)を装着し人工心肺から離脱, 25時間後にVABからも離脱したが術後49日目に敗血症,多臓器不全により死亡した.剖検で腹腔内膿瘍を伴う重症急性膵炎が認められた.開心術後の急性膵炎は一般にまれとされてきたが,補助循環に伴う多臓器不全の一病態として,留意する必要があると考える.