Toshio Konishi

Intraoperative Map Guided Operation for Atrial Fibrillation Due to Mitral Valve Disease

BACKGROUND This study was designed to determine if intraoperative atrial activation mapping facilitates operations for chronic atrial fibrillation associated with mitral valve disease. METHODS Surgical treatment guided by intraoperative electrophysiologic mapping was performed in 12 patients with chronic atrial fibrillation associated with isolated mitral valve disease. In 10 of 12 patients, regular and repetitive activation (cycle length ranged from 118 to 210 msec) originated in the left atrial appendage and/or orifice of the left pulmonary vein. In the remaining 2 patients, dominant repetitive activation and sporadic complex activation were alternately observed in the left atrium. However, the activation sequence of the right atrium was extremely complex and chaotic. RESULTS On the basis of intraoperative mapping, surgical procedures, including resection of the left atrial appendage and/or cryoablation of the orifice of the left pulmonary vein, were applied on the breakthrough site of the repetitive activation. No surgical procedure was performed on the right atrium in 11 patients. Ten of 12 patients (83%) have maintained sinus rhythm for 6 to 40 months (average 24.8 months) after operation. CONCLUSIONS In the majority of the patients with isolated mitral valve disease, the left atrium acts as an electrical driving chamber for chronic atrial fibrillation. Computerized intraoperative mapping should guide surgeons in determining the appropriate surgical procedure for chronic atrial fibrillation.

AUTOLOGOUS BLOOD TRANSFUSION WITH RECOMBINANT HUMAN ERYTHROPOIETIN IN HEART OPERATIONS

The effects of recombinant human erythropoietin (rHuEPO) on improving the anemia associated with autologous blood collection before open heart operations and on improving the postoperative anemia were studied. The study was carried out on 18 patients undergoing coronary artery bypass operations; 400 mL of autologous whole blood was taken from each patient 2 weeks before operation and was subsequently used in the operation, and rHuEPO (100 U.kg-1.day-1) was given intravenously for 2 weeks before operation and for 1 week after operation. The group in which iron preparations were also administered intravenously was designated as group I (10 patients), and the group in which rHuEPO was given alone was designated as group II (8 patients). In group III, as a control group, 11 past patients were used in whom 400 mL of autologous whole blood was collected 2 weeks before operation but neither rHuEPO nor iron preparations were given. After autologous blood collections, the hemoglobin levels improved in group I, group II, and group III, in that order, and with significant differences among them. It was shown that rHuEPO was effective in ameliorating the anemia associated with preoperative autologous blood collection, and the effect was further enhanced with intravenous supplementing iron preparations. After operation, the anemia markedly improved while rHuEPO was administered, but the hemoglobin levels decreased rapidly when the administration was terminated. Further studies are needed regarding the use of rHuEPO after operation.

Preoperative use of erythropoietin for cardiovascular operations in anemia

Erythropoietin was used in 10 patients undergoing elective cardiovascular operations who were compromised with anemia. Initially, their blood hemoglobin levels were less than 10 g/dL (range, 7.5 to 9.9 g/dL). Erythropoietin (600 to 700 units/kg per week) was administered intravenously or subcutaneously for about 2 to 12 weeks. Blood hemoglobin levels increased in each patient (11.0 to 14.5 g/dL) until the day of operation, and during this course autologous blood donations (400 to 1,200 mL) were obtained from 8 patients. As a result, homologous blood transfusions were needed in only 1 patient in whom erythropoietin treatment was interrupted for other reasons. All these patients were discharged without event, and no adverse effects due to erythropoietin were found. Although the causes of anemia were not specified in some of these patients, it was noteworthy that erythropoietin was effective even in a patient with hypoplastic bone marrow. Subcutaneous use was assumed to be especially favorable in managing anemic patients, in whom preoperative erythropoietin treatment could be continued for up to 82 days. We conclude that erythropoietin would be beneficial for the anemic population to secure homologous-blood-free operations.

Hybrid-type stabilizer for off-pump direct coronary artery bypass grafting

We have developed a mechanical stabilizer for use in off-pump direct coronary artery bypass grafting. We consider it an improvement on the sucker-type stabilizer, although it uses the mechanisms of the compressor-type. Our hybrid stabilizer effectively immobilizes the local heart surface with light compression and low evacuation. We believe that its use will eliminate the need for further immobilization and thus reduce cardiac invasiveness.

Extended aortic replacement in acute dissection by the separated elephant trunk technique

BACKGROUND Extensive aortic replacement in acute dissection is currently not a widely accepted method of treatment. METHODS We developed a safe method for extended aortic repair including the aortic arch in type A acute dissection, and describe here its application in 5 cases. This method was based on a modification of the elephant trunk method and several other strategies. Most of the procedures were carried out under simple hypothermic circulatory arrest. RESULTS All patients recovered within 2 days without recurrent nerve injury. One patient suffered from unilateral upper arm palsy due to severe innominate dissection. Patients were all discharged and early postoperative computed tomography (CT) showed thrombotic obliteration around the elephant trunk. Follow-up CT after 4 to 18 months confirmed that thromboexclusion proceeded down to the distal end of the elephant graft in 1 patient and to the diaphragmatic level in 3 patients. Total obliteration was observed in the remaining 1 patient. CONCLUSIONS This technique enables extended aortic repair in acute dissection with no increase in morbidity, and effectively promotes thromboexclusion of the dissected lumen to a wider extent than conventional methods.

Persistent fifth aortic arch left subclavian aneurysm in an adult

Persistent fifth aortic arch is so rare an anomaly that only seven cases have been reported. We treated an adult with this anomaly in which there was a single lumen aortic arch, single arterial trunk and left subclavian aneurysm. The patient underwent corrective surgery. From an analysis of the eight cases, this anomaly can be divided into two groups, depending on the aortic arch. The first group of six had double lumen aortic arch. All in this group had intra and/or extra cardiac anomalies, and only two with only PDA underwent ligation. The second group of two had a single lumen aortic arch and corrective surgery was done. Thus, those patients with a persistent fifth aortic arch should be classed into the first or second group, according to the angiographical findings.

Coronary artery spasm during coronary artery bypass surgery: its diagnosis, treatment and prevention

Between 1982 and 1983, we experienced four cases of hemodynamic collapse accompanied by an ST-segment depression in the ECG lead II, shortly after the cessation of cardiopulmonary bypass. The bypass graft flows monitored in these patients during the hemodynamic collapse episodes were remarkably low. In three cases, nitroglycerin (0.5–1 mg) was injected directly into the vein graft, which increased the graft flow suddenly, returned the ST-segment to the baseline, and improved the circulatory condition. Since 1984, however, diltiazem has been used in the cardioplegic solution and postoperative drip infusion. Due to the introduction of this drug, coronary artery spasm has not been seen in any of our patients since. These findings show that the monitoring of ST-segment changes and bypass graft flows are useful in the early diagnosis of coronary artery spasm after myocardial revascularization. Direct infusion of nitroglycerin into the vein graft is effective for the treatment of spasm, while diltiazem is useful in the prevention of coronary artery spasm incidental to myocardial revascularization.

Update 2001: Preoperative use of erythropoietin for cardiovascular operations in anemia

Erythropoietin was used in 10 patients undergoing elective cardiovascular operations who were compromised with anemia. Initially, their blood hemoglobin levels were less than 10 g/dL (range, 7.5 to 9.9 g/dL). Erythropoietin (600 to 700 units/kg per week) was administered intravenously or subcutaneously for about 2 to 12 weeks. Blood hemoglobin levels increased in each patient (11.0 to 14.5 g/dL) until the day operation, and during this course autologous blood donations (400 to 1,200 mL) were obtained from 8 patients. As a result, homologous blood transfusions were needed in only 1 patient in whom erythropoietin treatment was interrupted for other reasons. All these patients were discharged without event, and no adverse effects due to erythropoietin were found. Although the causes of anemia were not specified in some of these patients, it was noteworthy that erythropoietin was effective even in a patient with hypoplastic bone marrow. Subcutaneous use was assumed to be especially favorable in managing anemic patients, in whom preoperative erythropoietin treatment could be continued for up to 82 days. We conclude that erythropoietin would be beneficial for the anemic population to secure homologous-blood-free operations.

Excellent Hemostatic Effects of Aprotinin in Coronary Artery Bypass Surgery and Some Problems.

冠状動脈バイパス術を対象として, アプロチニンによる体外循環時の出血量節減効果について検討を行った. アプロチニン群 (A群) は34例にアプロチニン200万単位を人工心肺回路内に投与し, コントロール群 (C群) として31例を比較した. 術中, ACTはA群で体外循環開始後60分まで延長がみられたが, 血小板数では全経過を通じて両群に差はなかった. 術中出血量は, A群366±112mlに対してC群514±190ml, 術後ドレーン出血量は, A群354±138mlに対しC群570±226mlと有意 (p<0.05) にA群で少なかった. この結果, 総出血量でもA群で720±199ml, C群1,084±346mlと, アプロチニン使用により冠状動脈バイパス術時の出血は非使用に比べ34%減少させることができた. 周術期の心筋障害についての比較を行うと, 発生率に差はみられなかったが, 良好な止血効果に起因するグラフト開存性への影響など, 今後は合併症に関する検討を要すと思われた.

Coronary Revascularization in a Patient with Calcified Aorta Using Ventricular Fibrillation without Aortic Cross-clamping.

上行大動脈に高度の石灰化病変がある54歳の女性症例に対して, 上行大動脈にまったく操作を加えずに冠動脈バイパス術を行った. 大腿動脈より送血カニューレを挿入して体外循環を行い, cardioplegia 液を使用せず大動脈非遮断低体温心室細動下に, 両側内胸動脈と右胃大網動脈の3本の動脈グラフトを使用して3枝バイパス術を施行した. 術後は脳合併症など起こすことなく順調に経過した. 上行大動脈の高度石灰化症例に対してはこの aortic no touch technique が安全かつ確実な手術方法と考えられた.