We conducted a clinical study on a newly developed large diameter vascular graft (Triplex^®, Terumo Corporation, Tokyo, Japan) with a non-biodegradable material used as sealing material, to evaluate its effectiveness and safety. Triplex^® grafts were implanted in 170 patients with either aneurysmal or occlusive arterial disease in either the thoracic artery, abdominal artery or iliac arteries, between October 2001 and March 2003. The patients consisted of 141 men and 29 women with an average age of 69.0±10.0 years old (mean±SD). In 82 patients, Triplex^® was implanted for the thoracic artery area, in 88, for the abdominal artery area. The cumulative graft patency rate 12 months after implantation was 100.0% in each area, there was no any abnormality such as occlusion or rupture from the trunk of Triplex^®. The distension ratio, which is the index of the dilatation resistance, was 1.03±0.06 as a whole (n=139), 1.03±0.06 in the thoracic artery area (n=73), 1.03±0.06 in the abdominal artery area (n=66). In other words the dilatation of Triplex^® was hardly observed. As manipulability during the operation, the following characteristics were evaluated; anastomosis, resistance to fraying, hemorrhage, conformability with the host vessel. Triplex^® was evaluated as “good” in 75% of all items accounted for 75% or more. A transitory rise thought to be due to the surgical stress immediately after the operation because of the change of temperature and laboratory findings (CRP, WBC) between implantation and discharge was observed, but then recovered to the normal levels of each patients at discharge and the re-elevation was not recognized. In 90 patients, 277 adverse events occurred. Although in 33 adverse events in 21 patients a causal relation with Triplex^® could not be excluded, most of them were already known events as complications which could occur after operation on the aorta. Therefore, it was confirmed that Triplex^® has certain advantages: 1) good manipulability, 2) good patency and dilatation resistance, 3) no inflammatory reaction related to Triplex^®, as a graft for the aorta.

The survival rate of patients with cardiac rupture due to a blunt trauma is low, therefore it is necessary to have a well-defined diagnostic and treatment plan in order to improve the survival rate. In 8 such patients transthoracic echocardiograms at the time of arrival at our hospital showed pericardial effusion with cardiac tamponade in all patients. The mean time between suffering the injury and arriving at the hospital was 186±185min, and the mean time between arrival and being brought to the operating room was 82±49min. Preoperative pericardial drainage was performed in 2 patients, and percutaneous cardiopulmonary support system was used in 2 patients. The rupture site was in the right atrium in 3 patients, the right atrium-inferior vena cava in 1 patient, the right ventricle in 2 patients, the left atrium in 1 patient, and the left ventricle in 1 patient. Extracorporeal circulation was used in 4 patients, and the injured site was repaired. We were thus able to save the lives of 6 of the 8 patients (survival rate 75%). Transthoracic echocardiography was easy to perform and effective for making an accurate diagnosis. Many such patients tend to have multiple traumas, but, if the patient is in a state of shock due to cardiac tamponade, the patient should be moved immediately to the operating room. It is important to provide circulatory maintenance until surgery, and pericardial drainage and PCPS are also effective additional treatment modalities.

A 72-year-old woman suffered sudden back pain 42 days after ascending aortic replacement for retrograde acute type A aortic dissection. Computed tomography (CT) revealed type B aortic dissection and a stenotic true lumen at the abdominal aorta. The celiac artery and the superior mesenteric artery (SMA) branched from the true lumen, but bilateral renal arteries were not found by DSA. Infrarenal abdominal aortic fenestration was performed at 6th day from onset, because of progressive renal dysfunction. Intestinal ischemia was not confirmed by laparotomy. After the Infrarenal aorta was clamped and transected, the proximal intima was resected in a U-shape. The proximal stump which was reinforced with teflon felt was anastomosed to an 18mm woven graft. Distal anastomosis was carried to the true lumen was carried out with closure of the false lumen. Regaining flow into the collapsed true lumen was observed by epiaortic echography. Postoperatively, continuous hemofiltration was required for several days until renal dysfunction was improved. CT showed reasonable expansion of the true lumen, and no findings of visceral ischemia except for partial infarction of the left kidney. DSA revealed that bilateral renal arteries were perfused from the true lumen through the fenestration. Neither aortic dilatation nor new ischemia have been recognized, but further close observation is necessary.

A 24-year-old man was transferred to our hospital because of traumatic rupture of the thoracic aorta suffered in a traffic accident. On admission, he had recovered from shock and was alert. Chest CT showed massive hematoma around the total extent of the descending aora and the intimal flap at the diatal descending aorta. We performed an emergency operation. Through left thoracotomy, we found dilatation of the descending aorta. Epiaortic echo revealed that the aortic intima was completely transecred between Th 10 and Th 11. The pseudoaneurysm was replaced with a Hemashield vascular graft under partial cardiopulmonary bypass. The intercostal artery was preserved. His postoperative course was uneventful and paraplegia was not seen. We reported a rare case of traumatic rupture of the distal descending thoracic aorta above the diaphragm followed by successful surgical treatment.

Concomitant occurrence of acute aortic dissection and atherosclerotic aneurysm is rare. In such a circumstance, rupture of the existing aneurysm is the more likely scenario. In general, atherosclerotic plaque frequently serves to terminate the dissection process. A 65-year-old man with an abdominal aortic aneurysm was admitted due to severe back pain. Emergency CT showed acute aortic dissection (Stanford B) with a partially thrombosed pseudo-lumen and fusiform abdominal aortic aneurysm. Hemolysis occurred due to compression of the true lumen by the thrombosed pseudo-lumen. Emergency abdominal aortic graft replacement was performed successfully.

A 69-year-old man was admitted for treatment of thoracic aneurysm. DSA revealed multiple aortic aneurysms: three true aneurysms which were located at the distal arch, the thoraco-abdominal aorta at the diaphragm level and the infrarenal abdominal aorta, 60mm, 55mm and 55mm in diameter, respectively and two pseudo-aneurysms which were located in the abdominal aorta just below the right renal artery and the right common iliac artery. We decided to perform a two-staged operation. Before the first operation, 1, 200ml of autologous blood was stored for perioperative blood transfusion. Initially, total arch replacement was performed using deep hypothermic circulatory arrest and antegrade selective cerebral perfusion. One month after the first operation, total thoraco-abdominal aorta replacement was performed by a retroperitoneal approach with mild hypothermia. The Th 9, 10 and 11 intercostal arteries were reconstructed. Distal anastomosis was performed at both common iliac arteries. Blood transfusion was not required for blood pooling and reduction of priming volume in the cardiopulmonary bypass system.

Aortic valve preservation is indicated in cases of aortic regurgitation caused by sinotubular junction (STJ) dilatation with ascending aortic aneurysm. We performed aortic remodeling using a tailored Dacron graft for the rupture of a large ascending aortic aneurysm. The patient was a 68-year-old woman. She was admitted in shock with cardiac tamponade. Chest CT showed a large ascending aortic aneurysm, 11cm in maximum diameter. Echocardiography demonstrated moderate cardiac effusion and massive aortic regurgitation. The ascending aorta was dilated from the STJ to the innominate artery, but the aortic valve appeared normal. We decided to preserve the native aortic valve. We performed aortic root remodeling using a 26mm Dacron graft (Yacoub's procedure). An intraoperative endoscopic study revealed the disappearance of aortic regurgitation (AR). The coronary arteries were reconstructed by the Carrel patch technique. Postoperative aortography revealed trivial AR, and the patient was discharged two weeks after the operation. We conclude that this technique avoids the complications associated with mechanical valve implantation and necessary lifetime anticoagulation.

This clinical study was peformed to clarify the postoperative cardiac functions after coronary artery bypass graft surgery in the cases associated with decreased left ventricular ejection fraction (EF) or increased end-diastolic volume index (EDVI). The patients were divided into two groups by preoperative EF. The EF of Group I ranged from 31 to 39% in 42 cases, and the EF of Group II was below 30% in 27 cases. Several parameters of cardiac function such as EF, peak ejection rate (PER), peak filling rate (PFR) or early diastolic peak filling rate were evaluated with radionuclide ventriculography. Postoperative mean values of these parameters significantly improved in both Group I and Group II compared to preoperative values. Although these parameters and left ventricular wall motion did not improve in the 7 cases with an EDVI over 140ml/m² in Group II, the clinical results of these 7 cases were good during the follow-up period except one case which preoperatively had frequent ventricular arrythmia. The clinical condition improved remarkably in the 3 patients who had preoperative angina pectoris among these 7 cases. Surgical indications must be carefully determined in cases with increased EDVI and frequent ventricular arrythmia.

We report two cases, a 58-year-old male and a 60-year-old female with acute aortic occlusion probably ascribable to intracardiac thrombosis associated with atrial fibrillation. Thrombectomy was performed at about 5.5 hours and 4 hours respectively, after the onset of occlusion, and revascularization was successful. To prevent MNMS after revascularization, about 2, 000ml of blood was taken from the femoral vein of the male patient, and 1, 000ml of blood from the female patient, and this blood was returned in the form of abluted erythrocytes in transfusion through a cell saver to the patients. We suspected slight myoglobinuria after the operations, but they did not develop MNMS because a urine volume of about 3, 000ml was maintained by administration of infusion solution and diuretics and by replenishment of electrolytes and correction of acidosis. It was concluded that the technique involving the removal of a large volume of blood from distal veins and its transfusion through a cell saver was effective in preventing MNMS.

To clarify the mechanism responsible for the increase in stroke volume (SV) due to training, we investigated the effects of interval training on the left ventricle using M-mode echocardiography. Six healthy male subjects volunteered to undergo 48 training sessions for 12 weeks (4 sessions· week^-1) One session consisted of five periods of exercise of 3-min duration on a cycle ergometer at a power output of 100% maximal O₂ uptake (Vo₂max), interspersed with 2-min recovery cycling at 50%Vo₂max. The echocardiograms at rest and during mild exercise (100W) were recorded before and after the training. The interval training significantly increased Vo₂max. Although there was no significant difference in SV at rest before and after the training, the training increased SV significantly during exercise. Before the training, there was a significant difference in left ventricular enddiastolic dimension (LVEDD) and left ventricular end-diastolic volume (LVEDV) at rest and during exercise. However, after the training, LVEDD and LVEDV during exercise were significantly larger than those at rest. These results suggest that interval training for 12 weeks increases diastolic filling (elasticity) of the left ventricle during exercise in healthy young men, partly contributing to the increase in SV due to the training.