[Aortic dissection after aortic valve replacement with an aorto-left atrial fistula; report of a case].

Aortocameral fistula is a rare complication of aortic dissection. We herein report a case of aortic dissection after aortic valve replacement (AVR) complicated with a fistula to the left atrium. A 76-year-old man who had undergone AVR 1 year previously, was admitted to our hospital because of facial edema and chest discomfort. On auscultation, a continuous murmur was heard at the left lower sternal border. Computed tomography revealed dissecting aneurysm of the ascending aorta and a fistula to the left atrium was suspected. Transesophageal echocardiography showed the fistula between the false lumen of the aneurysm and the left atrium. Ascending aorta replacement and closure of the fistula was performed. There was dense adhesion between the aortic root and the roof of the left atrium. It seems that postoperative adhesion plays an important role in formation of aortocameral fistula.

[Giant cardiac metastasis of myxoid liposarcoma causing cardiac tamponade; report of a case].

We report a very rare case of cardiac metastasis of myxoid liposarcoma. A 55-year-old man presented with dyspnea. Two and a half years ago, he underwent resection of myxoid liposarcoma in the left thigh. Magnetic resonance imaging (MRI) revealed a giant tumor occupying the pericardiac cavity and pressing the heart and consequently causing cardiac tamponade. The patient underwent surgery through a left thoracotomy approach. The pericardiac cavity was filled with a giant tumor with a stalk from the right ventricle and 2 small nodules on the main pulmonary artery. He was relieved from the symptom: however, he had a recurrence of the tumor at the same site 5 months after the operation. He underwent surgery for the removal of the second tumor; however, he died 49 days after the operation. Although cardiac metastasis is a very rare condition, its awareness is essential for careful long-term follow-up for the early detection of a metastatic cardiac liposarcoma after the resection of the primary tumor.

[Surgical technique of aortic valve replacement for small aortic annulus in elderly patients].

Recent reports have shown that aortic valve replacement in elderly patients over 65 years with atherosclerotic aortic stenosis and a small aortic annulus is possible by using a small sized bioprosthesis (Carpentier-Edwards pericardial valve). Here we present out surgical technique. Firstly, the native calcified aortic valve was removed completely to gain total exposure of the surrounding aortic root and sinus of Valsalva like Bentall procedure. Secondly, a small sized bioprosthesis was implanted with intermittent noneverting mattress 2-0 sutures with spaghetti and small polytetrafluoroethylene (PTFE) felt. Aortic annulus is the dilated by inserting Hegar dilator sizing from 25 to 27 mm. Therefore, aortic valve replacement for small aortic annulus in intra- or supra-annular position should be easily accomplished. Good surgical results and hemodynamic state were achieved in 25 consecutive cases using this technique.

[Ventricular free wall re-rupture after surgical treatment of ventricular free wall rupture due to acute myocardial infarction; report of a case].

An in-hospital 72-year-old male with complaint of anterior chest pain was presented with shock. Pericardial effusion was confirmed by echocardiography, and therefore, he was brought to the operating room immediately with diagnosis of ventricular free wall rupture. The repair was performed using fibrin glue, fibrin sheet, and pericardial patch. His post-operative course was uneventful until massive bleeding came through the chest tube on the 5th day from the initial surgery. The emergency sternotomy was made again for hemostasis. In the re-operation, an approximately 20 mm laceration along the proximal circumflex artery was found and this was successfully repaired with 2 pledgetted horizontal mattress sutures. It is important and necessary to treat a postoperative patient taking care of re-rupture.

[Combined valvular and coronary artery surgery].

Between 1990 and 1999, 78 patients underwent combined valvular coronary artery operation. Aortic valve disease was present in 49 patients, mitral valve disease in 23 patients, aortic and mitral valve disease in 6 patients. The average age was 67 years. Twelve patients had had a previous myocardial infarction. The average number of grafts inserted was 1.82 per patients, and the average number of artery grafts inserted was 0.96 per patients. The most number of grafts were placed prior to valve replacement or plasty. And periods of myocardial ischemia were kept at a minimum by coronary perfusion through free grafts. Preoperative mortality was 1.3%. And event fee ratio after operation was 95% (mean follow up 42 month). Therefore the operative risk of combined surgery is, in general, low and the long term results are favorable.

[A case report of aneurysm of the ductus arteriosus combined with mitral regurgitation].

A case with the giant aneurysm of the ductus arteriosus combined with severe mitral regurgitation is reported. 58-year-old male underwent MVR and patch closure of the ductal orifice for staged operation. The first operation was MVR and patch closure of the PDA orifice of the pulmonary artery end using retrograde cerebral perfusion (RCP) with deep hypothermic circulatory arrest (DHC). The second operation was performed on 3 months after the first operation using left thoracotomy approach, and patch closure of the ductal orifice via the aorta using RCP with DHC was performed. Upon following-up examination, the patient is now doing well 20 months after the initial surgery.

[Surgical treatment of intracardiac tumors in 25 patients].

For most intracardiac tumors, operation is the only means of therapy. In our institute, we have aggressively performed operation for intracardiac tumors regardless of histological type because resection for tumor had a beneficial effect on the hemodynamics with congestive heart failure. Twenty-five cases of cardiac tumors were operated upon from 1980 through 1998. The follow-up period ranged from 2 months to 19 years. The histological diagnoses of the tumors were as follows: benign tumors 24 (myxoma 21, papillary fibroelastoma 1, fibroma 1, angiomyolipoma 1) and malignant tumor (angiosarcoma 1). There was one hospital death in this series. In the New York Heart Association classification, the cardiac performances of intracardiac benign tumors after operation were Class I or II. The results of surgical treatment of intracardiac benign tumors were satisfactory both in short-term and in long-term. On the other hand the long term result of malignant tumor was extremely poor. A patient with angiosarcoma died 8 months later due to bone metastasis.

[Clinical study of emergency coronary artery bypass surgery].

Between January, 1996 and December, 1998, 29 patients were undergone emergency coronary artery bypass grafting (CABG) in our institute. Age ranged 34 to 85 years (mean 65 +/- 11 years, male:female = 25:4). Of 29 emergency cases, 3 were hospital death. Hospital mortality rate was 10.7%, which was significantly higher than the hospital mortality of elective CABG (1.4%) during the same period. The necessity of IABP before CABG was 72% in emergency cases (elective surgery: 0%). Thus the use rate of arterial grafts were 86.2% in emergency cases (elective surgery: 100%), the patency of the arterial grafts were 100%. It is important to make stable condition of the patients before the operation, and therefore it is important to make contact closely with the cardiologists for making stable condition and for lowering the operative mortality. And, we should use arterial grafts for the long term result as much as possible if it is an urgent operation.

[New screening method for coagulation abnormality including AT III deficiency during CABG].

In our institute, 1 ml of heparin is administered to the patients undergoing CABG before dissection and mobilization of the internal thoracic arteries (ITAs) and/or right gastroepiploic artery (GEA) to prevent possible thrombosis or coagulation tendency. Two patients with AT III deficiency underwent CABG and one of them died. The aim of this study is to know whether ACT check before and after administration of 1 ml of heparin is useful as a screening test of coagulation abnormalities including AT III deficiency. One hundred patients (84 males and 16 females) undergoing CABG were studied. Age ranged from 41 to 79 years (mean 64.8 +/- 8.0 years). One ml of heparin was administered to all the patients before ITAs and/or GEA were dissected and mobilized. ACT was doubly checked before (control ACT: c-ACT) and after (heparinized ACT: h-ACT) administration of heparin. ACT extension was defined as follows: ACT extension = (c-ACT)-(h-ACT). Mean c-ACT was 124 +/- 12 sec., h-ACT 188 +/- 26 sec. and ACT extension 64 +/- 24 sec. There were only 3 cases which ACT extension were less than 30 sec.: two of them were combined with AT III deficiency and the other was due to insufficient administration of heparin. In conclusion, examination of ACT after 1 ml administration of heparin is new, simple and convenient screening method for coagulation abnormalities including AT III deficiency during CABG.

[A case report of intrathoracic aneurysm of left subclavian artery].

A case of intrathoracic aneurysm of the left subclavian artery is reported. The case was 68-year-old male. Chest CT and angiography revealed an aneurysm of left subclavian artery (LSA) located the proximal portion of LSA. The chest was opened by fourth intercostal thoracotomy. We evaluated the intima of distal aortic arch and LSA by introperative direct echography using a small probe (finger tip size). Since there was no calcification or mural thrombi at the distal aortic arch, the aneurysm was resected using partial cardiopulmonary bypass and the orifice of LSA was closed direct suture. LSA was reconstructed with knitted Dacron graft (8 mm). Postoperative course was uneventful.

[Case report of successful treatment of patent ductus arteriosus with severe pulmonary hypertension in an adult].

A 40-year-old man was diagnosed as having PDA with severe PH by cardiac catheterization. We decided that surgery was indicated on the basis of 100% oxygen inhalation test. After 100% oxygen inhalation, left to right shunt changed from 37.8% to 61.5%, Qp/Qs changed from 1.43 to 2.60, and PVR changed from 1,199 dyne/sec/cm5 to 237 dyne/sec/cm5. We decided to perform surgery. Under extracorporeal circulation, PDA was safely closed by triple ligation and was directly closed after pulmonary arteriotomy. The postoperative course was uneventful. Severe PH was greatly improved, pulmonary artery pressure recovering to the normal range, by administering PGE1, prostacyclin (PGI2), and nitroglycerin.

[Coronary artery bypass surgery in patients aged 75 years and older].

Coronary artery bypass grafting (CABG) has been performed for elderly patients with increasing frequency. Several studies have shown that the rate of complications and mortality in elderly patients are higher than in younger ones. This report presents results of CABG in patients over 75 years old. From January 1989 to February 1997, 604 patients underwent CABG, of whom 20 patients (3.3%) were 80-86 years old (group A) and 57 patients (9.4%) were 75-79 years old (group B). We compared these two groups with 100 younger patients (group C). Preoperative use of intraaortic balloon pumping and the emergency operation were more frequent in patients of group A (emergency 45%, IABP 20%). And the proportion of the no blood transfusion procedures was lower in elderly patients (group A 20%, group B 18%, group C 82%). The number of grafts per patient (group A 2.45 +/- 0.62, group B 2.2 +/- 0.6, group C 3.2 +/- 0.6) and the number of arterial grafts (group A 1.25 +/- 0.62, group B 1.25 +/- 0.66, group C 2.1 +/- 0.53) were different between the groups. But CABG in elderly patients was performed with low hospital mortality (group A 0%, group B 0.18%) and significant symptomatic benefit. We conclude that CABG can be performed in elderly patients with acceptable mortality and acceptable quality of life, so patients should not denied operation because of an advanced age.

[A clinical study of retrograde cerebral perfusion in long duration].

The safety limit of retrograde cerebral perfusion (RCP) in aortic arch reconstruction was evaluated in comparison with long (> or = 60 min: group A = 28 cases) and short (< 60 min: group B = 88 cases) RCP time (RCPT). RCPT was 60-94 min in group A and 24-59 min in group B. Hospital mortality was 7.1% and 6.8% in group A and B, respectively. There was no case who was died due to cerebral insufficiency. Postoperative neurological complication was observed 3 in group A and 3 in group B. There was no significance between 2 groups. There were no significant differences in the time to awake, ICU stay, electroencephalogram, and cognitive functions between 2 groups. Based on these results, the safety limit of RCP is over than 60 min and, maybe, about 90 min. We monitored the increase of deoxygenated hemoglobin (HbR) during RCP using a near infrared spectroscopy (n = 55). Since HbR increased gradually during RCP, HbR reflects oxygen metabolism non-invasively in the brain. HbR can be one of useful indexes of the brain protection during RCP.

Neural, humoral, and metabolic control of coronary vascular resistance during exercise.

Neural, humoral, and metabolic effects on coronary vascular resistance were examined during exercise in conscious dogs, chronically instrumented for the measurement of aortic pressure, heart rate, and left circumflex coronary blood flow. Exercise significantly decreased coronary vascular resistance (CVR) in intact (INT) group, in which CVR was controlled by neural, humoral, and metabolic factors. In cardiac denervated (CD) group with pretreatment of alpha blocker (phentolamine, 2 mg/kg), in which CVR was controlled only by metabolic factor, exercise significantly decreased CVR. To eliminate metabolic effect on CVR, CVR was normalized by the product of CVR and double product (DP = mean aortic pressure x heart rate). CVR.DP did not change throughout the exercise in dogs with CD with alpha blocker. Thus, metabolic effect on CVR during exercise can be excluded by the product of CVR and DP. This calculation was applied to INT group with alpha blocker and CD group without blockers. The 12 km/h exercise significantly increased CVR.DP from 4.1 +/- 0.3 x 10(4) to 6.4 +/- 0.9 x 10(4) in INT group with alpha blocker, in which CVR was controlled only by neural factor, and from 2.8 +/- 0.2 x 10(4) to 4.5 +/- 0.5 x 10(4) in CD group, in which CVR was controlled only by humoral factor. These data suggest that 1) neural and humoral coronary vasoconstriction occurs during exercise, 2) neural and humoral vasoconstriction is overwhelmed by metabolic vasodilation, and 3) CVR.DP is a beneficial calculation for excluding metabolic effect on CVR during exercise.

Effect of exercise on fractional extraction of catecholamines by the denervated heart in conscious dogs.

To examine the applicability of Halter's assumption to the denervated heart during exercise, we measured the concentrations of norepinephrine (NE) and epinephrine (E) in arterial and coronary sinus plasma in cardiac denervated dogs. As the level of exercise was increased from 0 (at rest) to 3, 6, and 12 km/h, fractional extraction (FE) of NE significantly decreased from 51 +/- 7 to 39 +/- 5, 34 +/- 6, and 30 +/- 5%, respectively. FE of E did not decrease at exercise (at rest, 57 +/- 10; 3 km/h, 60 +/- 9; 6 km/h, 60 +/- 5; and 12 km/h, 66 +/- 6%). There was no significant difference between FE of NE and E at rest and at 3 km/h, but FE of NE was significantly less than that of E with 6 and 12 km/h exercise. We conclude that FE of NE by the denervated heart decreases during exercise, and that FE of NE and E are approximately equal at rest and at mild exercise, but not at strenuous exercise.

[Differences in loading condition and its effects for valve replacement between chronic aortic and mitral regurgitation].

In order to clarify the differences of left ventricular mechanics between chronic aortic and mitral regurgitation (AR and MR), 23 patients with AR and 17 patients with MR were studied by noninvasive techniques. There were no differences between two types of regurgitation in R/Th, LV dimension, LVEDVI, PWTd, LV mass I and mean blood pressure. However, the peak systolic wall stress (PSWS), ESVI and systolic blood pressure (sBP) of AR were significantly higher than that of MR. One month after valve replacement (VR), in AR all parameters decreased significantly expect increased PWTd. But in MR, blood pressure, LV systolic size and LV mass I were unchanged, although LVDd, LVEDVI, PSWS and R/Th decreased significantly. These results indicates that high PSWS in AR is diminished effectively after AVR by both effects of reduction of LV volume and sBP, although in MR, as a sBP is kept in low level, a drop of PSWS after MVR occurs only due to reduction of volume. Therefore, systolic function after MVR for MR with impaired myocardium may be more destroyed by relatively high afterload as it is difficult to diminish the volume, even if LV function was kept relatively in good condition before operation.

[Surgical treatment of acute pulmonary embolism--report of two cases].

Two surgical cases of acute pulmonary embolism with severe cardiocirculatory impairment were reported. In the first case, emergent open pulmonary embolectomy with cardiopulmonary bypass was not effective, and multiple and organized emboli were indicative. In the second case, complete pulmonary thromboembolectomy was accomplished under extracorporeal circulation with remarkable hemodynamic improvement. It was suggested that urgent pulmonary angiography was necessary for definitive diagnosis and medical treatment, and that indications for pulmonary embolectomy included all patients with massive emboli in the main branches of the pulmonary artery. Monitoring of pulmonary arterial pressure was important to assess the effect of thrombolytic therapy, and the system of emergent cardiopulmonary bypass was required for immediate and effective cardiopulmonary resuscitation.