Biomedical subjects
Publications and source records attributed to M Ikeshita.
A pediatric patient with medically refractory idiopathic ventricular tachycardia was successfully treated by surgical laser ablation. Application of laser on the normothermic beating heart enables continuous electrophysiological assessment. The histopathology of idiopathic ventricular tachycardia and the advantages of laser ablation are presented.
A case of cardiac foreign bodies leading to development of four varieties of automatic tachycardia is reported. A 51-year-old male with aortic regurgitation was admitted to our hospital because of palpitations. An electrocardiogram revealed junctional tachycardia with or without left bundle branch block, and two types of fascicular tachycardias. Computed tomography showed metallic foreign bodies from a fractured guidewire in the membranous portion of the interventricular septum, which was inadvertently retained when he underwent diagnostic cardiac catheterization at the age of 27.
A 16-year-old girl with medically refractory idiopathic ventricular tachycardia (VT) with ventricular fibrillation (VF) underwent cryoablations of the VT origin and received implantable cardioverter defibrillator (ICD). Intraoperative epicardial and endocardial mapping demonstrated the earliest activation site of VT in the infundibular septum of right ventricle. Cryoablations were applied through a pulmonary arteriotomy under mild hypothermic cardiopulmonary bypass with the heart beating. Because of the episodes of VF. ICD implantation was followed. Her postoperative course was uneventful and she remains free from VT and VF.
By reviewing the outcome, we studied the propriety of our principles for the treatment of type A acute aortic dissection in 45 patients, encountered during the 10-year period between 1981 and 1990. We conducted a comparative study of patients with a thrombosed false lumen (type T) and a patent false lumen (type P) to examine the effect of an acutely thrombosed false lumen on the prognosis of this disease. For the 25 patients treated in the first 6 years (1981-1986), operation was performed as soon as exact diagnosis was made, regardless of the presence of complications and the type or severity of the disease. Early death occurred in 9/20 operated cases and in 4/5 unoperated cases, so 13/25 patients died for a 52.0% mortality rate. For the 20 patients who received treatment in the latter period (1987-1990), we gave priority to conservative treatment for type T cases that were free from complications, and adopted a treatment method attaching greater importance to the resection of intimal tears. As a results, early deaths were observed in only 4 type P patients (20.0%) who underwent operation, a significant better result (p < 0.05). For patients in whom we were able to excise the intimal tear (30.0%, early mortality rate), the results were better than in those in whom the intimal tear were left alone (53.8%). The results were particularly good in type T patients (25.0% of them underwent intimal tear resection and 71.4% underwent no operation for the intimal tear).(ABSTRACT TRUNCATED AT 250 WORDS)
We report a technique to improve exposure of the mitral valve apparatus. This technique that combines superior left atriotomy and interatrial septotomy can be helpful in patients with a small left atrium and reoperation. It has been used effectively in five patients and potential complication with this procedure has not occurred. The operative technique and indication are discussed in this paper.
Malignant fibrous histiocytoma (MFH) has been rarely reported as a primary tumor of the heart. We present a case of a primary intracardiac MFH and review the 28 previous reports of this rare cardiac tumor. A 48-year-old woman underwent an operation for congestive heart failure (CHF) due to a left atrial tumor. A large multinodular tumor attached to the posterior wall of the left atrium and extended into the mitral annulus and the posterior leaflet of the mitral valve. The tumor was resected incompletely and mitral valve replacement was performed. Pathological diagnosis was MFH. The patient did well in the postoperative period, but she again presented with symptoms of CHF four months later. Chest CT and two-dimensional echocardiogram demonstrated a recurrent tumor of the left atrium. Since the tumor grew rapidly despite chemotherapy, a reoperation was performed to remove it. Nevertheless, as the tumor was found to have extended into the pericardial cavity and posterior mediastinum, only partial resection was possible. After a protracted operation, the heart failed to sustain the circulation and the patient died. The prognosis of intracardiac MFH was poor in spite of surgery, radiation and/or chemotherapy. However, repeated surgical treatments can relieve symptoms of CHF and may prolong the life of patients.
To facilitate surgical technique, we describe some devices on arterial graft anastomosis in coronary artery surgery. Prior to anastomosis, the graft is positioned closely just parallel to the coronary artery by fixing surrounding endothoracic fascia or other connective tissues to the epicardium with 5-0 monofilament sutures. Stitching around the heel of the anastomosis is best performed by "a single stroke continuous suture" with the graft kept in position parallel to the coronary artery. This technique provides simple and secure anastomosis of an arterial graft.
We discussed the operative concept of revascularization of lower extremities in patients associated with severe, coronary artery disease (CAD). Those with symptomatic CAD may undergo coronary artery bypass (CABG) or percutaneous coronary angioplasty (PTCA) with or without intraaortic balloon pump (IABP). Special attention should be paid during operation in these patients in order to reconstruct the arterial catheter route, which gives us the best way to percutaneous transfemoral approach to the aorta or the coronary arteries. One should not choose arbitrarily extra-anatomical bypass, such as axillo-femoral or femorofemoral, in these cases. Also, artificial graft should not be applied in the common femoral arteries, which will make percutaneous approach difficult. Common femoral arteries, if needed, are best reconstructed by means of thromboendarterectomy. Attaining smooth, bilateral aorto-ilio-femoral continuity is the main goal of revascularization of lower extremities in patients with CAD.
We performed coronary artery bypass grafting with the left internal mammary artery, right gastroepiploic artery, and inferior epigastric artery on a 60-year-old male. The inferior epigastric artery used as a free graft was placed between the in situ left internal mammary graft proximally and the obtuse marginal branch distally. Both the left internal mammary graft to the left anterior descending artery and the right gastroepiploic artery to the right coronary artery were used as an in situ graft. All grafts were patent two weeks after the operation and the patient was free from angina at three months follow-up period.
Recently, coronary artery bypass grafting operations for patients with total proximal multi-vessel coronary obstructions are increased. In these cases, antegrade cardioplegia through the aortic root has been applied as usual. But it seems to be difficult to deliver cardioplegic solution to myocardium uniformly beyond coronary stenosis. Retrograde coronary sinus cardioplegia in the presence of proximal coronary artery obstruction could maintain improved cardioplegic delivery and satisfactory myocardial protection. Because of the limitation of antegrade cardioplegia, retrograde cardioplegic technique has, once again, been cited as a reasonable alternative to antegrade cardioplegia. But on the other hand, retrograde cardioplegia includes the potential for relatively inadequate preservation of right ventricle based on the venous drainage communication to the coronary sinus. The object of the present work is mainly to evaluate the efficacy of retrograde coronary sinus cardioplegic technique for right ventricle by electrophysiological method. Thirty-six adult mongrel dogs divided three groups. Sixteen animals (Group I) received GIK cardioplegia through the coronary sinus, thirteen animals (Group II) received GIK added diltiazem cardioplegia through the same way, and seven animals (Group III) received GIK cardioplegia through aortic root. No large temperature gradients of myocardium between right and left ventricle in each group and also temperature gradients of right ventricle between three groups have been observed. The time duration from starting of injection of cardioplegia to disappear the electrical activity in right and left ventricle were 11.4 +/- 8.2, 3.4 +/- 1.2 minutes in group I, 2.9 +/- 1.5, 2.2 +/- 1.4 minutes in group II, and 0.9 +/- 0.4, 0.9 +/- 0.2 minutes in group III. The time duration from starting of injection of cardioplegia to reappear the electrical activity in right and left ventricle were 6.4 +/- 8.7, 13.4 +/- 7.9 minutes in group I, 20.0 +/- 3.5, 21.3 +/- 1.6 minutes in group II and 18.0 +/- 5.5, 18.7 +/- 4.5 minutes in group III. Unipolar peak-to-peak amplitude (UPPA) analysis reveals the condition of myocardial preservation during ischemic arrest and we compared preischemic UPPA with post-ischemic UPPA. In group I, UPPA declined of 44.1 +/- 29.3% in right ventricle and 72.7 +/- 27.6% in left ventricle, in group II, 78.7 +/- 28.7%, 81.9 +/- 23.6%, in group III, 71.4 +/- 18.7%, 76.7 +/- 9.89%. Analysis of ultrastructural changes in the myocardium are shown that injury was most manifest in the right ventricle of group I, but in group II, ultrastructure of right ventricle maintained nearly normal condition.(ABSTRACT TRUNCATED AT 400 WORDS)
Among various methods to treat ventricular tachyarrhythmia (VT) in the presence of acute myocardial infraction, the surgical approach is a somewhat unsatisfactory method in case of preoperative acute hemodynamic deterioration. The transatrial approach with the "topical" application of Lugol solution on left ventricular (LV) endocardium, without left ventriculotomy, i.e. a transatrial chemical ablation method; has been reported in our department as suggestive to being efficacious. The objective of the present study is to investigate the occurrence of left bundle branch block (LBBB) and the like, as well as to examine the impact on heart function, particularly LV function, by employing the just-above mentioned approach. 15 mongrel dogs were being experimented on. Through a left transatrial approach toward LV endocardium and the application of Lugol solution, with pulmonary artery flow being as constant; we measured pre- and post-operative left atrial (LA) pressure, LV pressure, aortic pressure, LV functional shortening, and stroke volume. In addition, the same protocol was also employed in another group, with the application of physiologic normal saline solution, instead. A comparative study was made between the two groups. In the Lugol solution group, postoperative LA pressure and LVEDP showed a tendency toward exhibiting higher values, when compared to preoperative readings. However, no significant difference was observed in this setting. Furthermore, in comparison with postoperative readings in the saline group, the mean LA pressure in the Lugol solution group exhibited a tendency toward somewhat higher values. Nonetheless, no significant difference was observed in LV functional shortening between the two groups; though it is known a LBB pattern could be noticed on ECG in the Lugol solution group.(ABSTRACT TRUNCATED AT 250 WORDS)
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We studied the healing processes of operative cardiac wound around the patch on 8 patients (5 males, 3 females), who survived 6 to 147 days postoperatively for postinfarction ventricular septal perforation. The perforation was repaired either with a Dacron patch or with a Teflon-backed glutaraldehyde-preserved equine pericardium (Xenomedica). The patients with the Xenomedica patch had no perioperative bleeding or residual shunting across the patch. However, our long-term observations show that the patch is not covered with neoendocardium after 5 months and thus may pose a greater risk for thrombus formation, embolisms or infections; For instances, one case with mural thrombus formation and two cases of infection around the patch were observed. Therefore, while the Xenomedica patch may provide advantages in the immediate postoperative period, long term results indicate that this patch is inferior to the Dacron patch. We have also observed that the progress of healing was different on the patch between the right and left surface. Neoendocardium was observed on the 30th postoperative day on the right sided surface of the Darcron patch, while only pseudoneointima (mostly fibrinous membrane) with a few endothelial cells were found on the left side. The healing of infarcted myocardium was slower in these patients with patch than in patients with myocardial infarction without operation. Even after 62nd postoperative day, scarring was still incomplete, only granulation tissue was observed. Certainly, the operative trauma including the effect of extracorporeal circulation and postoperative low output syndrome may contribute to this finding. Suture insufficiency occurred in 4 cases, which may be associated with the delayed wound healing.(ABSTRACT TRUNCATED AT 250 WORDS)
Left ventricular free wall rupture (LVFWR) complicating myocardial infarction is still a lethal complication. Although there have been reports of successful repair of LVFWR, most of them were of subacute type in which main symptom was cardiac tamponade and the surgical repair was undertaken several hours after the onset of rupture. Between March, 1984 and June, 1987. We treated 12 cases of LVFWR surgically, thoracotomy and open drainage in 2 cases, thoracotomy and direct closure of rupture in 8 cases, median sternotomy and patch closure of rupture in 2 cases. We used cardiopulmonary bypass (CPB) only in 3 cases, because most of the cases except two developed electromechanical dissociation abruptly, requiring an emergency thoracotomy and there was no time for establishing CPB. In the cases of electromechanical dissociation, cardiopulmonary resuscitation and an emergency thoracotomy were performed simultaneously. There were three early survivors (greater than 30 days) by emergency thoracotomy and direct closure of rupture and one survivor (double rupture case) by patch closure on CPB. We believe that acute type of LVFWR in which initial symptom is electromechanical dissociation without any preceding symptoms can be rescued by emergency thoracotomy and direct closure of rupture with no aid of CPB if rupture is a small tear of anterior or lateral left ventricle. For this purpose, prompt diagnosis is mandatory and this is possible by two dimensional echocardiogram even during cardiopulmonary resuscitation.
A patient who had received balloon atrioseptotomy and B-T shunt operation previously experienced recurrent episodes of supraventricular tachycardia, and was refractory to medical treatment since the age to 3. At 9 years, the patient underwent intraoperative electrophysiological mapping which confirmed the earliest breakthrough at the crux of posterior septal region. Rastelli's operation and division of posterior septal Kent was simultaneously performed successfully. Post operative ECG was normalized with abolition of delta wave, and PSVT was gone. We concluded that the division of Kent bundle should be simultaneously performed with operative reconstruction in patients with congenital heart disease and WPW syndrome on postoperative care for SVT.
Recently, many types of pacemakers and the surgical interventions based on the fundamental research have been introduced for the treatment of various arrhythmias which are classified as brady- and tachyarrhythmias. In general selection of pacemaker for bradyarrhythmias, VVI pacemaker is used for the patients with atrial fibrillation. However, a more appropriate pacing therapy for this disease would be VVIR. For sick sinus syndrome with normal atrioventricular conduction, AAIR mode is best. DDDR pacemakers are more appropriate for use in the patients with atrioventricular conduction disturbances. A number of surgical procedures been developed specifically for the purpose to abolish refractory tachyarrhythmias. Especially refractory ischemic ventricular tachyarrhythmias (VT) are more difficult to treat surgically than supraventricular tachyarrhythmias. Our operative results indicate that the recurrence of VT results almost in postoperative death in the patients with pleomorphic VT. The direct operation including the implantation of AICD should be considered mainly for those patients. In this field, we considered the progressive ME devices to be essential for the continued improvement of the results.
A method using cryosurgery has been previously described to selectively ablate atrioventricular nodal reentry tachycardia while preserving intact atrioventricular conduction. The purpose of the present study was to define the histologic features of the cryolesions in relationship to the specialized conduction system. In 12 adult dogs a series of nine discrete cryolesions was placed along the perimeter of the triangle of Koch while continuously monitoring the His bundle electrogram. All animals survived the operation and maintained intact atrioventricular conduction. At 14 weeks after surgery the hearts were sectioned and examined. In all 12 animals there was a confluent mass of dense fibrous tissue present in the lower atrial septum that was in immediate proximity to but did not involve the atrioventricular node-His bundle. The ablation of perinodal tissue with preservation of the specialized conduction system with the use of this cryosurgical technique was confirmed. It is likely that the cryoablated perinodal tissue represents the proximal common pathway of the circuit for atrioventricular nodal reentry tachycardia.