[Removal of methicillin-resistant staphylococcus aureus infected pacemaker leads under cardiopulmonary bypass: report of a case].

A 71-year-old man, who underwent an intravenous pacemaker implantation previously, suffered from fever and local infection of the generator pocket. A blood culture showed positive for methicillin-resistant staphylococcus aureus (MRSA). He underwent removal of total pacemaker system under cardiopulmonary bypass support successfully. Two leads were tightly adhered to the right atrial free wall, tricuspid valve and right ventricular trabeculation. Postoperative course was uneventful with administration of antibiotics for 5 weeks. Removal under cardiopulmonary bypass is considered to be an effective procedure for treatment of patients with infected pacemaker lead.

[Mid-term outcome of aortic arch operation for true aneurysms; using an axillary artery perfusion].

To prevent cerebral infarction during perioperative period, we have used an axillary artery for systemic perfusion and selective cerebral perfusion for aortic arch operation. Since 1996, 34 aortic arch operations were performed in our institution. Simultaneous 5 CABGs, 4 AVRs, 2 aortic root replacements and 1 MVR were performed. There were 2 hospital deaths (5.9%, sepsis and acute heart failure) and only 1 (2.9%) cerebral infarction. There were no deaths in patients over 75 years of age and in patients with extensive aneurysm which were replaced by 2-staged operation. Overall 3 years survival was 94.1% with no further death. We conclude that aortic arch operation through an axillary artery perfusion and with hypothermic selective cerebral perfusion can be performed with very low mortality and morbidity.

Mixed venous oxygen saturation as a promising parameter for physiologic control of total artificial heart.

Mixed venous oxygen saturation (SvO2) has been proposed as one of the suitable parameters for physiologic control of a total artificial heart (TAH). To establish the practical application of SvO2, we investigated the response of cardiac output (CO) and SvO2 to step-loaded exercise. A normal calf was surgically equipped with an ultrasonic flowmeter probe and an oximetry catheter in the pulmonary artery to measure CO and SvO2, respectively. Three stage step treadmill exercise tests (1, 2, and 4 km/h) were performed three times. While CO increased from 8.9 L/min at preexercise level to 9.7, 10.2 and 11.4 L/min at 1, 2, and 4 km/h, respectively, SvO2 decreased from 59.6% to 56.8, 55.3, and 52.2%, respectively. There existed a linear correlation between the magnitude of changes in CO and SvO2. CO and SvO2 exhibited a similar course of change, expressing an inverted exponential curve. The time constant of SvO2 was from 19 to 35 seconds, whereas that of CO was from 21 to 39 seconds. We conclude that SvO2 changes in close association with CO during exercise and has good potential to be a parameter for physiologic control of a TAH, by reflecting the recipient's CO demand without conspicuous time delay.

[Postoperative chylothorax treated with fibrin glue and absorbent mesh: a case report].

A 66-year-old man was treated by graft replacement for a thoracic aortic aneurysm. Chylothorax occurred on postoperative day 2. In spite of cessation of oral intake and IVH management, chest tube drainage did not decrease, the patient became malnourished. A chest X-ray and CT scan revealed the massive pleural effusion. Reoperation assisted with a thoracoscopy was carried out for chylothorax on postoperative day 27. Because we were unable to find the thoracic duct and the leakage point, the fibrin glue and absorbent mesh was applied to parietal and mediastinal pleura. Four days after reoperation, the chest tube was removed. This method is useful for this type of a chylothorax and lymphorrhea.

Aprotinin reduces the expression of p-selectin on the surface of platelet and leukocyte-platelet conjugates.

P-Selectin, an adhesion molecule expressed on the surfaces of activated platelets and the vascular endothelium, mediates platelet binding to monocytes and neutrophils. Monocytes and neutrophils produce superoxide anion by activated platelets through p-selectin. Aprotinin, a serine protease inhibitor, inhibits plasmin to activate platelets during cardiopulmonary bypass (CPB). A total of 25 patients were studied to clarify the effects of aprotinin on p-selectin expression during CPB. Nine patients were not given aprotinin (control group), and 16 were given aprotinin of 2 million U in the priming solution (aprotinin group). The platelet count and soluble p-selectin in the plasma, p-selectin on the surface membranes of platelets, and leukocyte-platelet conjugate levels were measured during and after CPB. The platelet count was maintained well in the aprotinin group. The increases of soluble p-selectin in the plasma, platelet surface p-selectin, and leukocyte-platelet conjugates were less in the aprotinin group than in the control group (p < 0.05). In conclusion, aprotinin in patients undergoing CPB may reduce the early inflammatory reactions induced by p-selectin.

[Size estimation method for patch used in reconstruction of LV cavity].

The reconstruction of LV cavity is accomplished by suturing a patch to the viable myocardium to exclude the infarcted area from the high LV pressures. However, there is no clear guideline to estimate the size of patch used for LV reconstruction. We have designed a new method to determine the correct patch size, and applied it in 5 cases. The suture line of the patch is at the junction of contractile (functional) and infarcted portions of LV. The patch size is determined by the length of AB, termed "a", as the base, where "point A" represents the junction on the LV anterior wall side, and "point B" the junction of the LV posterior wall side, from RAO 30 degrees projection of the left ventriculogram obtained by cardiac catheterization. In LV aneurysm, we designed the patch in the range of a/2 < l < or = pi a/2, where patch length on RAO 30 degrees is considered "l". An effort was made to reconstruct to normalize LV volume and contour by designing the patch size to be a/2 < l < a, particularly when the contractile portion was enlarged by aneurysm. On the other hand, in post AMI VSD, LV contractile portion is not enlarged in early stage. Therefore, the patch was designed in the range of a < l < or = pi a/2 to maintain LV volume. Postoperative LV volume can be calculated prior to surgery, by using the lengths of the designed patch. Postoperative analysis indicated that the actual LV volume and contour were almost identical to our estimation. This method is very useful in planning the patch size for LV reconstruction.