Evidence and Challenges for Left Atrial Appendage Management / 日本心臓血管外科学会雑誌

The left atrium and left atrial appendage have unique genetic anatomical and physiological features. Recently, advances in diagnostic imaging technology have provided much new knowledge. Clinically, the risk of developing atrial fibrillation increases with age. In order to reduce the public health burden such as cerebral infarction caused by atrial fibrillation, we need to find some predictive risk factors and preventive strategies for cerebral infarction and more effective treatments. The new concept of atrial myopathy has emerged, and animal models and human studies have revealed close interactions between atrial myopathy, atrial fibrillation, and stroke through various mechanisms. Structural and electrical remodeling such as fibrosis and deterioration of the balance of autonomic nerves and complicated interactions between these mechanisms lead to deterioration of atrial fibrillation and a continuous vicious cycle, and finally thrombosis in the left atrial appendage. Although anticoagulant therapy for patients with atrial fibrillation is strongly recommended, it is difficult for many patients to continue optimal treatment. In the nearly future, it will be important to understand the anatomy and physiology of the left atrial appendage and to understand the shape changes, size and the changes of autonomic function, and thrombus formation conditions associated with LAA remodeling during atrial fibrillation, and then we should provide early therapeutic intervention.

Effect of Sildenafil on Pulmonary Hypertension after a Case of Residual Shunt of Ventricular Septal Defect / 日本心臓血管外科学会雑誌

A 60-year-old man, who underwent repair of ventricular septal defect (VSD) 40 years previously, presented with dyspnea on effort and leg edema. Further examination showed residual VSD, mitral and tricuspid valve insufficiency, atrial flutter and pulmonary hypertension. We performed repair of the residual VSD, mitral valve replacement, tricuspid valve annuloplasty, and the Maze procedure. After surgery, systolic pulmonary arterial pressure decreased from 70 to 39 mmHg. On the 4th postoperative day, his hemodynamic state was stable and he weaned from ventilator. He showed hypoxia with sticky excretions, and reintubation was done 10 h after extubation. After intubation, pulmonary hypertension continued, nitroglycerine administration was not effective but inhaleted nitric oxide (NO) improved pulmonary hypertension. On the 15th postoperative day, sildenafil administration from nasogastric tube was started the day before extubation. On postoperative echocardiogram on the 35th postoperative day, the systolic pulmonary arterial pressure was 30-40 mmHg and left ventricular function was severely impaired because of the paradoxical movement of the ventricular septum after repair VSD. Sildenafil was safely used for the patient with heart failure and secondary pulmonary hypertension associated with congenital heart disease.

Apicoaortic Conduit for Aortic Valve Stenosis after Coronary Bypass Grafting / 日本心臓血管外科学会雑誌

The patient was a 74-year-old man with a history of previous aorto-coronary bypass grafting 14 years previously. Echocardiography showed severe aortic valve stenosis. Computed tomography showed severe circumferential aortic calcification of the whole aorta, including the aortic root. Coronary cineangiography showed patency of the endoric graft. Avoiding graft injury and aortic cross clamping, we performed apicoaortic conduit. His postoperative course was uneventful, he was discharged very much improved on the 11th postoperative day. This procedure is useful in high risk patients with aortic valve stenosis.

Lower Mini-Sternotomy for Direct Coronary Artery Bypass on the Beating Heart / 日本心臓血管外科学会雑誌

Although left anterior descending coronary artery (LAD) grafting with a left internal thoracic artery (ITA) on a beating heart via a small left anterior thoracotomy (LAST) has become widely accepted, significant limitations exist due to the limited surgeon experience, smallness of exposure, thus making harvesting of the ITA, visualization of the surgical field and anastomosis quite difficult. Patients often have significant pain and wound complications postoperatively. A lower mini-sternotomy approach in 4 patients was performed from December 1998 through January 1999. Results: The length of mini-sternotomy incision is 7 to 14cm. These operations were accomplished without morbidity or mortality. No patients required intraoperative conversion to conventional bypass. Postoperative angiography showed patency of graft without stenosis of the anastomosis in all 4 patients. The patients did not complain of significant pain and their postoperative hospital stay was 5 to 11 days. The lower mini-sternotomy approach or“xyphoid” approach proposed by Benetti seems to be an excellent novel approach giving the freedom of extension of the incision if needed with satisfactory exposure for left ITA harvest and access to LAD as well as the distal RCA, and causes less postoperative incisional pain.

Operative and Late Results of Conventional CABG / 日本心臓血管外科学会雑誌

This study reviewed the operative results in patients who underwent elective isolated coronary artery bypass grafting (CABG) from 1991 to 1997 and the long-term outcome in patients who received an internal thoracic artery (ITA) to left anterior descending artery graft from 1984 to 1995. The morbidity rates were as follows: low output syndrome (LOS), 19 (2.6%); perioperative myocardial infarction (PMI), 14 (1.9%); IABP required, 9 (1.2%); respiratory insufficiency, 32 (4.4%); acute renal failure, 28 (3.8%); mediastinitis, 9 (1.2%); stroke, 13 (1.8%); and reoperation for bleeding, 9 (1.2%). Operative mortality was 0.7%. Patients with moderate or severe impairment of left ventricular function (ejection fraction≤40) or chronic renal failure had high incidences of arrthythmia and respiratory insufficiency; those who were 75 or older at operation had a higher incidence of arrhythmia than those who were 50 or under (<i>p</i>=0.033). Patients who received four or five grafts needed a longer duration of hospitalization than those who received a single graft (<i>p</i>=0.0147). The 10-year actuarial survival rate, cardiac death-free rate and cardiac event-free rate in the entire series were 89.4%, 96.7%, and 80.9%, respectively. Among patients who underwent complete revascularization, the 10-year cardiac event-free rate and catheter intervention-free rate were 82.7% and 91.7%, respectively, compared with 77.5% and 84.2% in patients who underwent incomplete revascularization (<i>p</i>=0.0428, 0.0343). Since this study demonstrated that CABG with cardiopulmonary bypass contributed to favorable operative and long-term results, the indications for minimally invasive direct coronary artery bypass (MIDCAB) and off-pump CABG should be considered carefully and perhaps limited to elderly patients and/or those with major co-morbidities, until the long-term benefits have been clarified.

Effectiveness of Erythropoietin in Elderly Coronary Bypass Patients / 日本心臓血管外科学会雑誌

The effectiveness of recombinant human erythropoietin (rHuEPO) was evaluated in elderly patients who underwent coronary artery bypass grafting. A total of 133 patients were divided into three groups: those who were 70 years of age or older and received rHuEPO (group I; <i>n</i>=32), those who were also 70 years of age or older but did not receive rHuEPO (group II; <i>n</i>=35), and those who were 60 years or younger and received rHuEPO (group III; <i>n</i>=66). In 87.5% of group I, 42.9% of group II, and 98.5% of group III, homologous blood transfusion could be avoided. The percentage of patients without homologous blood transfusion was significantly higher in group I than in group II (<i>p</i><0.001). The rate of homologous blood transfusion was significantly higher in group I than in group III (<i>p</i><0.05), but rHuEPO had equal effects in terms of increase in hemoglobin level in the two groups. Furthermore, in patients without anemia, the rate of homologous blood transfusion was almost the same in the two groups. In conclusion, the administration of rHuEPO enables even elderly patients to undergo coronary artery bypass grafting without homologous blood transfusion.