[PT-INR as a parameter for anticoagulant therapy after valve replacement surgery].

We retrospectively analyzed the intensity of anticoagulant therapy in the 195 patients who underwent valve replacement surgery with mechanical valves. An optimal level or target range of prothrombin time-international normalized ratio (PT-INR) was sought. Previously, we employed a range of 10 to 25% of thrombotest value, which corresponded to the range of 1.5 to 3.5 of PT-INR value. In one patient who underwent mitral valve replacement, PT-INR valve was 1.72 when he developed an episode of cerebral thromboembolism. There was no tendency in PT-INR value in 51 patients who developed non-critical bleeding. As a while, PT-INR value was over 4.0 in 2 patients who required a in-hospital treatment for major bleeding complications. Based on our experience, we recommend a range of 2.0 to 3.0 of PT-INR value after valve replacement surgery with mechanical valves.

[Resection of intra-atrial tumor thrombi from renal malignant tumors with the use of cardiopulmonary bypass and temporary exsanguination. An experience based on 4 cases].

We report 4 patients, 1 female and 3 males aged 26-74 years, who underwent surgical treatment for renal malignant tumors with supradiaphragmatic extension into the vena cava. All of their tumor thrombi extended to the right atrium as confirmed by magnetic resonance imaging. The distinctive symptom was liver dysfunction caused by disturbance of the hepatic vein drainage in two patients. However, there was no common symptom in these 4 patients. Preoperative metastasis was found only in the female, whose metastasis was solitary in the lung and seemed to be able to be removed easily after radical nephrectomy. All of these 4 patients had radical nephrectomy and removal of the tumor thrombi with the use of cardiopulmonary bypass and temporary exsanguination. In 3 of these patients, the liver was mobilized to expose the retrohepatic vena cava by incision of the falciform, triangular and coronary ligaments. Two patients with vena caval wall invasion had vena cavectomy and an artificial vascular graft was then sutured to replace the caval wall in one of them. Preoperative liver dysfunction was gradually improved after operation and completely recovered about 1 week later. A postoperative complication, wound infection, occurred in only one patient. Pathological examination revealed renal cell carcinoma in 3 patients and nephroblastoma in the remaining one. In renal cell carcinoma, both patients without distant metastasis were alive about 15 months postoperatively. However, the one with lung metastasis died with newly appeared multiple metastases 9 months postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical application of evoked spinal cord potentials elicited by direct stimulation of the cord during temporary occlusion of the thoracic aorta.

Evoked spinal cord potentials elicited by direct stimulation of the cord were used to monitor spinal cord ischemia in 68 patients undergoing temporary occlusion of the thoracic aorta (29 thoracic nondissecting aortic aneurysms, 9 nondissecting thoracoabdominal aneurysms, and 30 dissecting aneurysms). "Immediate" postoperative paraplegia developed in three patients and "immediate" paraparesis developed in one, whereas "delayed" paraplegia developed in two others. During aortic crossclamping, four response patterns of the spinal cord potentials were obtained: (1) no change (n = 53), (2) change with return (n = 10), (3) change with inconsistent return (n = 2), and (4) change without return (n = 3). Neurologic complications occurred in 2%, 0%, 100% of these groups, respectively. Delayed paraplegia developed on the second postoperative day in only one patient with a false-negative result, and the potentials correlated well with this patient's clinical neurologic recovery. The aortic crossclamp time was significantly longer in the patients with "change with inconsistent return" and "change without return" than in the other two groups (p < 0.01). Femoral artery pressure and the cardiopulmonary bypass flow rate were also significantly lower in these groups than in the other two groups (p < 0.02 and p < 0.01, respectively). We conclude that intraoperative monitoring of direct spinal cord responses is useful for the early detection of spinal cord ischemia for assessing the efficacy of surgical countermeasures.

Marginal closure of non-gamma2 amalgam.

In order to investigate the effect of burnishing on the marginal closure of non-gamma2 amalgam restorations, a single-composition high-copper alloy (Indiloy), a conventional lathe-cut alloy (Lunargent Alloy), and a conventional spherical alloy (Shofu Spherical) were each mixed with mercury and filled in transparent plastic cavities. Half of the specimens were burnished along the cavity margins immediately after packing and again after carving. The remainder was unburnished. A dye was sprayed on their occlusal surfaces after 24 hr and leakage indicated by the dye penetration was observed through the plastic walls, and following facts were found: 1. Burnishing markedly decreased the leakage of all type alloy amalgams. 2. When burnished, the marginal leakage with the high-copper alloy was remarkably less than with the conventional spherical alloy but slightly more than that with the lathe-cut alloy. 3. The difference in the marginal leakage and in the effect of burnishing among the three amalgams was apparently related to their setting dimensional change curves.