Akira Furuse

Percutaneous coronary angioscopy in patients with ischemic heart disease

Percutaneous transluminal coronary angioscopy was performed during routine coronary angiography in seven patients and during PTCA in one patient with ischemic heart disease. A flexible fiberscope with an external diameter of 1.4 mm was introduced through an 8F or 9F guiding catheter used for PTCA into the coronary arteries. Warmed saline solution (15 to 20 ml) was injected through the guiding catheter into the coronary arteries for replacement of blood. Twenty-one of the 31 coronary segments were visualized and photographed on color cinefilms. The lumen of the atherosclerotic segment showed narrowing with smooth surface or with spiral folds. PTCA caused dilatation of the stenosed segment with scattered thin thrombi. These findings indicate the usefulness of angioscopy to observe luminal changes in the coronary arteries of patients with ischemic heart disease.

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.

Application of a new tactile sensor to thoracoscopic surgery: Experimental and clinical study

BACKGROUND We developed a new tactile sensor that could quantify the hardness of objects as changes in the resonance frequency of the sensor (delta f). We have applied it to thoracoscopic operations for the localization of small invisible nodules in the lung. METHODS When the sensor probe was moved over the lung surface, a delta f curve was depicted on the computer screen. When the sensor tip reached a point directly above a hard object, a sudden upward jump of the delta f curve was evoked. After experimental studies using pigs, the sensor was applied in 8 patients. More recently we produced a needle sensor to distinguish small nodules from bronchi that may evoke similar upward jumps of the delta f curve. Eight nodules and four bronchi in resected human lungs were probed directly using this sensor. RESULTS In all of the patients, the hardness of various thoracic structures could be quantified. A total of 10 nodules were found using the sensor and resected thoracoscopically. The needle sensor distinguished nodules from bronchi, as the mean delta f of the bronchial walls (-64 +/- 45.9 Hz) was significantly higher than that of nodules (-526 +/- 168 Hz, p < 0.001). CONCLUSIONS Thoracoscopic detection of small and invisible pulmonary nodules using our new tactile sensor is feasible.

Excellent survival in a subgroup of patients with intrapulmonary metastasis of lung cancer

BACKGROUND Recently, intrapulmonary metastases in non-small cell lung cancer have been considered to have less influence on prognosis than extrapulmonary metastases. We report a subgroup found among patients with intrapulmonary metastases showing a good prognosis. METHOD A retrospective study was performed on 236 consecutive patients with non-small cell lung cancer who underwent surgical resection of their tumors. Intrapulmonary metastases were found histopathologically in 50 of them, and their clinicopathologic features were investigated. RESULTS Analysis of postsurgical results revealed a subgroup of patients showing excellent prognosis (n = 15). They had well-differentiated adenocarcinomas with bronchioloalveolar spread and pT1-2 N0, without vascular or lymphangitic invasion. Their actuarial 5-year survival rate was 100%, with a mean survival interval to date of 28 months. However, none of the other 35 patients survived for 5 years, with a mean survival interval to date of 11 months. CONCLUSIONS We have clarified that patients with histopathologically diagnosed intrapulmonary metastases from non-small cell lung cancer do not constitute a homogeneous group. Pulmonary metastases with good prognosis, which are considered to be hematogenous metastases, may be benign lesions such as adenomatous or atypical adenomatous hyperplasias mimicking malignant tumors.

Tuberculous Pseudoaneurysm of the Thoracic Aorta

Tuberculous pseudoaneurysm has been reported to be a fatal, but rare complication of tuberculosis. We report a case of a 68-year-old man who underwent successful surgical treatment for a tuberculous pseudoaneurysm of the thoracic aorta with bronchial communication, and review previous reports of patients who also underwent operation for similar lesions, focusing especially on the pathway of infection to the aorta.

Doppler analysis of flow velocity profile at the aortic root.

This study of aortic root flow velocity profiles suggests that the flow velocity pattern is parabolic rather than flat as has been widely supposed. To analyze the distribution of flow velocity, a special ultrasound pulsed Doppler velocity flow meter, with a direct probe on the aortic wall, was designed. Sixteen patients, none with a diagnosis of aortic valve disease, were examined just before undergoing open heart surgery. Parabolic velocity patterns were always found, and it was determined that the parabola was skewed rightward toward the anterior wall. Furthermore, it was shown that the flow velocity vector was initially directed toward the commissure of the right coronary and the noncoronary cusps.

Nonreentrant supraventricular tachycardia due to double ventricular response via dual atrioventricular nodal pathways

Narrow and wide QRS tachycardias associated with various rhythm disturbances were recognized during 24-hour ambulatory eletrocardiographic monitoring in a 65-year-old man with coronary artery disease. Laddergram analysis revealed the presence of dual atrioventricular nodal pathways. Non-reentrant supraventricular tachycardia due to simultaneous fast and slow conduction through the dual atrioventricular nodal pathways was confirmed by electrophysiologic study. The atrial rate determined the occurrence of simultaneous conduction, and extrastimulation failed to induce a double ventricular response. Enhanced vagal activity was thought to play a critical role in provoking this phenomenon. Radiofrequency catheter ablation of the slow pathway eliminated the arrhythmias.

Sinus node function after mitral valve surgery via the transseptal superior approach.

OBJECTIVE The transseptal superior approach can offer an excellent view of the mitral valve but the incision almost always transects the sinus node artery. The purpose of this study was to evaluate the sinus node function after mitral operation by this approach. PATIENTS AND METHODS We reviewed the electrocardiograms of 76 patients who underwent mitral valve operations either via transseptal superior approach or via right lateral atriotomy. Nine patients who maintained the sinus rhythm for more than one year after surgery via the transseptal superior approach were selected for electrophysiological study to evaluate the sinus node function. RESULTS AND CONCLUSIONS Postoperative electrocardiographic and electrophysiological studies revealed that the sinus node function after the transseptal superior approach was relatively well maintained for more than one year after the operation. The influence of the transseptal superior approach on the sinus node function in the mid-term postoperative period was apparently mild and did not cause a serious problem. However, some of the patients did show abnormal data in terms of sino-atrial conduction time and intrinsic heart rate. Therefore, further follow-up of the sinus node function is necessary in patients who underwent mitral surgery through the transseptal superior approach.

Successful management of massive pulmonary tumor embolism from renal cell carcinoma

Renal cell carcinoma occasionally invades the inferior vena cava and rarely extends to the right atrium. However, despite the frequency of venous extension, it is unusual to recognize patients with massive pulmonary tumor embolus clinically. We describe a 60-year-old man who underwent pulmonary tumor embolectomy using cardiopulmonary bypass combined with profound hypothermia and intermittent low-flow perfusion. The patient is currently alive and well without implantation metastasis 6 months after the operation.

Atrial ablation with an IRK-151 infrared coagulator

BACKGROUND The purpose of this study was to develop a method of atrial ablation. In the IRK-151 infrared coagulator, light from a tungsten-halogen lamp is focused into a quartz rod. The distal exit plane is connected to a tip made of sapphire to allow linear ablation. METHODS Thirty-six lesions were created in 9 mongrel dogs. The beating ventricular myocardium was ablated from the epicardium. In each dog, 4 lesions were created by using the following durations of application: 3, 9, 15, and 21 seconds. After the ablation, the myocardium was fixed and stained. A linear lesion on the beating right atrial free wall was created. Before and after the ablation, epicardial plaque-electrode mapping was performed. Three months after ablation, remapping was performed. RESULTS The ablated myocardium had well-demarcated necrosis without carbonization or vaporization. The maximum depth was 10.3 +/- 0.8 mm. The conducting pathway was blocked. The block, once made, continued for 3 months. CONCLUSIONS The IRK-151 produces well-demarcated lesions that were deep enough for atrial ablation to block the conducting pathway.