T cells are divided into two subsets, alphabeta and gammadelta, according to the T-cell receptor (TCR) expressed. Recent findings indicate that gammadelta T cells serve as the first defense against microbial pathogens, and represent a link between innate and acquired immunity. We conducted a study to investigate the changes in circulating TCR subsets after cardiac surgery in children. Blood samples from 24 children who underwent cardiac surgery with cardiopulmonary bypass (CPB) were collected serially to analyze TCR subsets by flow cytometry. The alphabeta T cells reached a nadir on postoperative day (POD) 1, but recovered to pre-CPB levels on POD 3. On the other hand, the gammadelta T cells decreased after CPB and did not recover to pre-CPB levels even after POD 7. The alphabeta/gammadelta T-cell ratio was increased after POD 3. In children, gammadelta T cells recover more slowly than alphabeta T cells after cardiac surgery. These changes in TCR subsets may contribute to postoperative immunosuppression.

Preoperative autologous blood donation is commonly performed to avoid homologous blood transfusion during cardiac operations in adult patients. 1 However, autologous blood donation for children is hampered by technical problems including lack of an adequate blood collection system and acute anemia after blood collection. Given the life span of children, it is most important to avoid the complications of homologous transfusion. 2 We describe a technique of scheduled autologous blood donation during preoperative cardiac catheterization and examine the efficacy and safety of this method for use in infants and children.Technique. Cardiac catheterization was performed about 2 weeks before elective operations in infants and children weighing at least 5 kg. Autologous blood donation was performed in patients with a hematocrit value of 33% or more and a hemoglobin value of 11 gm/dl or more. Sedation was achieved with thiopental sodium and local anesthesia was achieved with lidocaine hydrochloride. Sheaths were inserted into the femoral artery and vein. After hemodynamic measurements, but before contrast angiography, 10 ml/kg of blood was collected via the arterial sheath. The same volume of lactated Ringer's solution was infused at the same rate through the venous sheath.Collected blood was stored as packed red cells and plasma or as whole blood. Blood erythropoietin concentrations were measured before and after blood collection, and recombinant human erythropoietin (100 U/kg) was administered intravenously to acyanotic patients on the first and seventh days after blood collection. Cyanotic patients were not treated with recombinant human erythropoietin. Each patient was given ferrous sulfate (2 mg/ kg) orally every day.Results. From October 1995 through September 1997, preoperative autologous blood donation was performed in 27 children, including 13 infants (16 boys and 11 girls). Their ages ranged from 6 months to 6 years, 8 months (average 1.9 -+ 2.1 years). Their body weights ranged from 5.8 kg to 20.2 kg (average 9.7 -+ 5.5 kg). The patients From the

A 62-year-old man was brought to the emergency room of our hospital because of chest pain. Computed tomography revealed a right aortic arch and an aberrant left subclavian artery with Kommerell diverticulum and acute aortic dissection (Stanford type A). Total arch replacement was performed emergently through a median full sternotomy. A stomach feeding tube was placed postoperatively for the patient to receive nutrition, and esophageal bleeding was observed postoperatively. The patient died because of the bleeding. Autopsy findings showed a communication between the esophagus and Kommerell diverticulum. Rupture of Kommerell diverticulum and perforation of the esophagus were indicated.

The patency of coronary artery bypass grafts was evaluated by helical computed tomographic (CT) scan. One hundred forty patients who received an enhanced chest CT scan and a coronary angiography after bypass surgery were studied before discharge at the Fukui Cardiovascular Center. Among them was a total of 398 grafts and 436 anastomoses. For the evaluation of 248 vein grafts, the CT scan showed a 99.5% correct positive ratio and an overall accuracy of 96.4%. In 122 internal thoracic arteries tested, an overall accuracy of 64.7% was obtained. In gastroepiploic artery tests the overall accuracy was 33.3% and in radial artery tests it was 45.5%. Thirty‐seven venous sequential anastomoses in 34 grafts and 1 internal thoracic artery sequential anastomosis were also evaluated. In the venous sequential anastomosis, the CT scan showed a 73.0% of accuracy overall. This study showed that the helical CT scan was useful to evaluate graft patency following bypass surgery. Cathet. Cardiovasc. Intervent. 46:322–326, 1999. © 1999 Wiley‐Liss, Inc.

Radiofrequency (RF) catheter ablation has been used for the treatment of ventricular tachycardia (VT), however, in some patients VT might result from subepicardial macroreentry that could be successfully terminated by epicardial approach. This study examined the feasibility of thoracoscopic RF ablation of myocardium from epicardium using a custom made electrode. In five mongrel dogs, the thoracoscope was introduced through the 7th intercostal space. A 500-KHz continuous wave RF energy was connected to a custom made multiple electrode probe. Under thoracoscopic guidance, the heart was exposed and the RF probe was introduced. RF ablation was performed on the nonvascular ventricular wall of the beating heart. The left ventricular free wall and right ventricular outflow tract were satisfactorily visualized and ablated. The total dose of RF energy ranged from 50 to 500 J, and the estimated volume of ablated lesions ranged from 41.0-799 mm3. There were significant correlations between the RF discharge output and the irradiated lesion volume (P < 0.01), and the depth of the lesions (P < 0.01). Grossly, after RF ablation the ventricular myocardium demonstrated a circular, well-demarcated area of thermal injury. Volume and depth of the lesion depended upon the total dose of delivered RF energy. Thoracoscopic RF ablation appears to be a minimally invasive and useful method for creating irradiated myocardial lesions from epicardial surface. This method could be technically feasible for the treatment of Vts for which endocardial RF ablation is ineffective.