Chiharu Enoki

Surgical treatment for a ruptured thoracic aortic aneurysm.

OBJECTIVE The treatment for a ruptured thoracic aortic aneurysm remains controversial. This study was undertaken to assess the outcome from surgery. METHODS Between 1993 and 1998, we have performed 19 operations for a ruptured thoracic aortic aneurysm. Patients with an impending rupture or a chronic false aneurysm were excluded. There were 11 men and 8 women, with a mean age of 70.5 +/- 6.7 years. The aneurysm was caused by dissection in 8 patients. Of these, 7 were acute (Stanford type A, 6; type B, 1), and the other one was chronic (type B). Aortic rupture occurred into the pericardial cavity (n = 7), into the left lung (n = 6), the mediastinum (n = 3), the pleural cavity (n = 2), or into the esophagus (n = 1). Severely unstable hemodynamics were noted in 12 patients with a rupture into the pericardium, mediastinum, or pleural cavity (Group A). Inotropic support was required in each of these patients. Metabolic acidosis developed all but 1 patient. The 7 patients with a rupture into the lung or esophagus coughed or vomited blood (Group B). The operative approach was anterior (n = 17) or lateral (n = 2). Grafts were placed in the ascending aorta (n = 4), ascending and transverse arch aorta (n = 7), transverse arch aorta (n = 3), or in the descending thoracic aorta (n = 5). Selective cerebral perfusion was used in 13 patients. RESULTS There were 5 hospital deaths (26.3%). The postoperative complications included central nervous system dysfunction (n = 3), low cardiac output syndrome or cardiac arrhythmias (n = 3), respiratory failure (n = 4), acute renal failure (n = 1), and local or systemic infections (n = 4). The perioperative event-free rate was 36.8% overall, 25% in Group A, and 57.1% in Group B. CONCLUSIONS Patients with unstable hemodynamics require prompt operative intervention. Rupture into the esophagus is associated with a high mortality rate. Rupture in a thoracic aortic aneurysm can be successfully treated with emergency surgery.

Efficacy of autologous platelet-rich plasma in thoracic aortic aneurysm surgery

OBJECTIVE Allogenic blood transfusion can transmit viral infection or cause immunological side effects. Recently, improved operative techniques have required less frequent transfusions in thoracic aortic aneurysm surgery. This study examined the efficacy of using autologous platelet-rich plasma in thoracic aortic aneurysm surgery. METHOD Eight patients underwent nine operations using an autologous platelet-rich plasma program. The control group consisted of 15 historic patients matched for operative procedure and age. All operations were performed by the same surgeon. The platelet-rich plasma program required the collection of platelet-rich plasma prior to the infusion of heparin; platelet-rich plasma transfusions were administered following neutralization by heparin. RESULTS The volume of platelet-rich plasma averaged 252 +/- 14.3 ml; total platelets in the platelet-rich plasma were 2.27 +/- 0.20 x 10(11) cells. The median number of homologous red blood cells transfused during the operative day was 0 units (range 0 to 12) in the platelet-rich plasma group and 3 units (range 0 to 25) in the controls. The median number of homologous fresh frozen plasma was 0 units (range 0 to 20) in the platelet-rich plasma group, and 5 units (range 0 to 30) in the controls. The platelet-rich plasma group received significantly fewer transfusions. CONCLUSION Autologous platelet-rich plasma transfusion was an effective way to reduce homologous blood transfusions in thoracic aortic aneurysm surgery.

Right ventricular myxoma in a 71-year-old female

Right ventricular myxoma in elderly is very rare and this is the 36th case report of right ventricular myxoma in Japan. A healthy 71-year-old female with no symptoms or constitutional signs except heart murmur was hospitalized. Findings of transthoracic echocardiogram, CT scan, MRI and angiocardiogram demonstrated a mobile tumor in the right ventricular outflow tract. Transesophageal echocardiogram clearly revealed that the stalk was arising from the right ventricular free wall. Under cardiac arrest, right atriotomy was made and a gelatinous tumor (4.5 x 2 x 2 cm in size, 7.3 g in weight) was excised with 5 mm of surrounding endocardium and a few millimeters of underlying myocardium through the tricuspid valve. Histopathologically, the tumor was diagnosed as a myxoma. Her postoperative course was uneventful.

Saccular aneurysm in the left main coronary artery

The patient was a 70-year-old male with a chief complaint of chest pain. Coronary angiography revealed a saccular aneurysm of 11 mm in diameter at the furcation of the left main coronary artery. Triple vessel disease was also seen. At surgery, it was judged that the risk to rupture of the aneurysm was high because the aneurysmal wall was very thin. Therefore, the blood flow into the aneurysm was blocked, and coronary artery bypass grafting was performed. In a pathological study on the aneurysmal wall, no atherosclerotic and no inflammatory changes were found, but acidic mucopolysaccharides were detected in the tunica media. Coronary aneurysms with coronary stenosis in the elderly have been reported to be arteriosclerotic without exception. Here we present this rare case of a left main coronary artery aneurysm with coronary stenosis in an old-aged patient, considered to be due to metabolic abnormalities in the smooth muscle cells.

A case in which biventricular assist device support was required after aortic valve replacement with a bioprosthetic valve.

We report the case of a 45-year-old man with severe aortic regurgitation. The patient underwent aortic valve replacement with a bioprosthetic valve, but was unable to be weaned from cardiopulmonary bypass (CPB). Intraoperative coronary angiography revealed stenosis of the right coronary orifice, so an intra-aortic balloon pump was inserted and coronary artery bypass grafting to the right coronary artery was conducted; however, weaning from CPB again failed. Left ventricular assist using a Gyro centrifugal pump was performed between the left atrium and left femoral artery, along with right ventricular assist using a Nikkiso centrifugal pump between the right atrium and pulmonary artery. Flow rates averaged from 2.0 to 2.8 l/min for the left-side ventricular assist device (VAD) and 2.1–3.8 l/min for the right-side VAD. The bypass rate reached approximately 70% at maximum. No thromboembolic events were documented during VAD support. The patient underwent explantation of VADs on postoperative day 4. No thrombus was identified on the bioprosthetic aortic valve by transesophageal echocardiography. The left-side pump displayed no thrombus, while the right-side pump had a small thrombus at the shaft. The patient was discharged from the hospital and was alive as of 2 year postoperatively. To the best of our knowledge, no clinical study has yet compared the antithrombotic properties of two centrifugal pumps in one patient where mechanical support was performed for the same duration and flow rate.

Reliability and efficacy of a monitoring system for an implanted pulse generator

Abstract The Selection 900/900E is a physiological pacing device with a sophisticated monitoring system for detecting and analyzing atrial arrhythmias. We have investigated the reliability and efficacy of the Selection monitoring system. Twelve patients with episodes of atrial tachyarrhythmias were implanted the with Selection device (7 men, 5 women, aged 73 ± 6 years old). Ten patients had sick sinus syndrome and two patients had a high degree of atrioventricular (AV) block. All patients underwent 24-h external Holter monitoring after the operation (136 ± 41 days) to evaluate the accuracy of the data recorded by the internal monitoring system. There was no significant difference in counter data between the 24-h external Holter and the internal monitoring systems. Four patients recorded an episode of atrial fibrillation by both systems. In two patients, the 24-h external Holter monitoring system misread DDI pacing after mode switching as sinus rhythm or pacing failure. In another patient, the featured function of this pacing device for atrial tachyarrhythmia was recognized as a sensing failure by the 24-h external Holter monitoring system. The Selection 900/900E monitoring system is a reliable and informative way to evaluate the relevance of pacing therapy.