胸部外科

Objective：Although the Cox-maze operation is the standard surgical procedure for permanent atrial fibrillation（AF）, conversion to sinus rhythm is limited by patient characteristics, including the duration of AF, atrial size, and voltage of fibrillation waves. A surgical strategy based on structural alteration of the electrical substrates of AF is required to achieve better outcomes of AF surgery. Complex fractionated atrial electrogram （CFAE） plays an important role in the electrical substrate of AF. We performed AF surgery guided by preoperative CFAE mapping using a 3-dimensional （3D） mapping system. This study evaluated the early results of our procedure. Methods：From January 2015 to August 2016, 8 patients （mean age：66.5±6.4 years） underwent CFAE mapping-guided AF surgery. In the preoperative electrophysiological study using 3D mapping, CFAE was defined by a low voltage electrogram （0.05～0.25 mV） with a highly fractionated potential （short cycle length ＜120 msec）. First, right atrial CFAE sites were ablated by using a catheter ablation system. Several days after right-sided CFAE ablation, a modified Cox-maze operation was performed with additional cryoablation of CFAE sites. Results：There were 1～3 （mean：2.5 ±0.8） CFAE sites in the right atrium and 2～4 （mean：2.4±0.7） sites in the left atrium. Mean CFAE mapping time was 87.6±24.6 minutes, fluoroscopy time was 53.1±22.2 minutes, and volume of contrast agent was 44±3 ml. Concomitant cardiac surgery included mitral valve plasty in 6 patients, and aortic valve replacement and mitral valve replacement in 1 patient each. The mean time for CFAE mapping-guided AF surgery was 25.7±5.6 minutes. At discharge, 7 patients were in sinus rhythm and 1 patient still had AF, but sinus rhythm recovered at 3 months postoperatively without anti-arrhythmic medication. After a mean follow-up of 11.7±8.5 months, all patients remained in sinus rhythm. Conclusions：Early results suggest that CFAE mapping-guided atrial fibrillation surgery is feasible and effective. Although the long-term effect of CFAE ablation on maintenance of sinus rhythm and atrial function should be evaluated, this novel method could provide an alternative strategy for the surgical treatment of AF.

A cross-sectional study is conducted with primary residents attended wet labs at Tohoku University Hospital Advanced Medical Training Center in order to investigate the efficacy of the training, especially focused on the animal ethics. The 41 participants answered questionnaires in regard to non-technical skills, technical skills and ethics before and after the practice. To identify differences in each ethical question between 2 time points, Wilcoxon signed ranks test was used because the data was not normally distributed. As the result of it, all animal ethical questions showed significant differences（0.0016≦p≦0.0380, α＝0.05 level of significance）. Beside them, only 1 out of 5 general ethical questions showed it （p＝0.0137）. This outcome verified that the lecture of animal ethics and the observation of animal care in this center fixed in the training curriculum clearly induced participants’ psychological movements.

In recent years economic sense is required in hospital management, the national university hospital is also no exception. We performed duty improvement efforts as well as the current state analysis in the department of cardiac surgery for the purpose of revenue optimization in our hospital. At result, we succeeded in the improvement of the medical index as well as medical profit and found the key of solution to the serious problem that national university hospital has.

Anomalous aortic origin of coronary arteries is rare. We report 3 cases of surgical treatment for anomalous aortic origin of coronary arteries. Case 1 was a 38-year-old man who was saved by the use of an automated external defibrillator from cardiopulmonary arrest while exercising. The coronary angiogram showed the right coronary artery arising from the left coronary sinus of Valsalva and being located between the aorta and the pulmonary trunk. He underwent coronary artery bypass grafting （CABG） using the right internal thoracic artery with ligation of proximal part of right coronary artery to prevent sudden death. Case 2 was a 76-year-old woman with the left coronary artery arising from the right coronary sinus of Valsalva and proximal left anterior descending coronary artery stenosis. She underwent CABG. Case 3 was a 58-year-old man with severe aortic valve regurgitation. He underwent aortic valve replacement. During weaning from cardiopulmonary bypass, the electrocardiogram revealed ST-segment elevation. Transesophageal echocardiography showed intramural segment of the left coronary artery and obstruction of the left coronary blood flow. Repair was accomplished by unroofing the intramural segment. All the cases were successfully treated by surgical treatment.

We report a rare case of aneurysmal formation of the left brachial artery complicated with infective endocarditis of the mitral valve. A 67-year-old man was referred to our institution for further examination of pulsatile mass at the left upper extremity. Computed tomography showed a left brachial arterial aneurysm with a diameter of 4 cm and gradual expansion of the aneurysm was also recognized. Furthermore, echocardiography revealed severe mitral valve regurgitation with a vegetation. There was no feature of congestive heart failure. He was diagnosed with subacute infective endocarditis and infective left brachial arterial aneurysm. Considering these clinical findings, staged surgical treatment was planned. He underwent resection of the brachial arterial aneurysm and bypass grafting with an autologous saphenous vein on an urgent basis. One month after the initial operation, elective mitral valve plasty was successfully performed. Although aneurysmal formation of the brachial artery subsequent to infective endocarditis is rare, we should keep this potentially serious complication in mind.

We performed salvage surgery after chemoradiotherapy（CRT） in a patient with thymic basaloid cell carcinoma. A 46-year-old man with an abnormal chest shadow on X-ray findings was referred to our hospital. Computed tomography revealed a partially solid tumor along with a multilocular cyst in the anterior mediastinum with mediastinal lymph node swelling infiltrating to the superior vena cava（SVC）. Positron emission tomography revealed FDG accumulation （SUVmax 7.94）in the tumor. Pathological findings of a tumor biopsy specimen obtained by thoracoscopy led to a diagnosis of thymic basaloid cell carcinoma. Following CRT （ADOC＋RT：60 Gy）, a complete resection （R0）with replacement of the SVC was performed. The postoperative course was uneventful, and the patient was alive at 20 months after surgery with metastasis to the cervical lymph nodes and bone.

Basaloid squamous cell carcinoma （BSC） of the lung is a rare variant of squamous cell carcinoma （SCC） and is reported to show poor prognosis. A 70-year-old man presented to the clinic complaining of a productive cough. Computed tomography（ CT） of the chest revealed a nodule in the left lower lobe of the lung. A bronchoscopy and transbronchial lung biopsy（TBB） were performed twice；no evidence of malignancy was found. So we followed up by periodic chest CT. One year and 4 months after the 1st visit, the nodule increased in size from 14 to 19 mm. TBB was performed again and the tumor was diagnosed as SCC. The patient underwent a left lower lobectomy and the tumor was diagnosed as BSC by postoperative pathological examination. Two years and 6 months after surgery, no recurrence has been observed in the patient.