ABSTRACT
We investigated the effects of rewarming speed on cerebral circulation and oxygen metabolism during cardiopulmonary bypass (CPB). Twenty-four adult patients who had undergone open heart surgery with moderately hypothermic CPB were divided into two groups. In the slow rewarming group (group S), the rates of increase of blood temperature were under 0.1°C/min. In the rapid rewarming group (group R), they were more than 0.1°C/min. Mean blood flow velocity in the middle cerebral artery (mean MCAv) was measured by transcranial Doppler ultrasonography, and the index of cerebral oxygen consumption was evaluated by Doppler-estimated cerebral metabolic rate for oxygen (D-CMRO<sub>2</sub>). The change of oxyhemoglobin level in the brain (Oxy Hb) was monitored by near-infrared spectroscopy. In group S, mean MCAv and D-CMRO<sub>2</sub> changed in a parallel manner following the changes of the rectal temperature throughout the periods, and mean MCAv was always higher than D-CMRO<sub>2</sub>. In group R, however, the rate of increase of D-CMRO<sub>2</sub> was more rapid than that in group S from the beginning of rewarming, and D-CMRO<sub>2</sub> exceeded the level of mean MCAv just before termination of CPB. In addition, Oxy Hb in group R showed more rapid changes than that of group S. In conclusion, rapid rewarming during CPB may cause the disruption of cerebral flow-metabolism coupling.
ABSTRACT
A 73-year-old man complained of sudden severe back pain and was admitted to a community hospital on February 2, 1994. DeBakey IIIb aortic dissection was diagnosed and he was treated conservatively. He noted a pulsating mass in his abdomen on June 7, 1995 and was referred to our hospital. Because of a decrease in platelet and fibrinogen and increase in FDP, local disseminated intravascular coagulation was diagnosed. Since abdominal pain continued, impending rupture was suspected. Computed tomogram showed abdominal aortic dissection and multiple iliac aneurysms. As coagulopathy did not improved by medical treatment, we performed prosthetic graft replacement of the aortio-iliac system on September 4, 1995. Before operation, the effectiveness of heparin was confirmed. After the operation local disseminated intravascular coagulation improved without drug therapy.
ABSTRACT
We experienced two rare cases of acute aortic dissection with leg ischemia after Y graft repair of the abdominal aortic aneurysma. Case 1 was a 63-year-old woman who had received Y graft repair at age 55, and case 2 was a 28-year-old man with Marfan's syndrome who received a Y graft repair at age 21. Both patients sustained DeBakey type I dissections terminating at the suture line of the Y graft and had symptoms of acute arterial occlusion of bilateral lower extremities. Emergency operation was performed 8 hours after onset in case 1 and 6 hours after in case 2. Case 1 could not be weaned from cardiopulmonary bypass because of intraoperative rupture and acute heart failure, but case 2 underwent successfully aortic root replacement and total arch replacement under selective cerebral perfusion.
ABSTRACT
A 64-year-old man with a history of anterior blunt trauma 10 years previously was admitted to our hospital complaining of general fatigue. A plain chest roentgenogram showed pericardial calcification. Computed tomography and echocardiography showed the mass to be a calcified capsule in the anterior mediastinum compressing the right side of the heart. He underwent an operation through a median sternotomy. The mass was an organized hematoma encapsulated by a calcified fibrous and serous layer of the pericardium. The hematoma was resected together with the calcified pericardium under cardiopulmonary bypass. His postoperative course was uneventful. He had no history of hemopericardium but had experienced blunt chest trauma that seemed to have induced the subsequent localized constrictive pericarditis.
ABSTRACT
The purpose of this study was to examine the responses of cerebral blood flow and metabolism to changes in arterial carbon dioxide tension during moderate hypothermic cardiopulmonary bypass in patients with cerebrovascular disease undergoing open heart surgery. Computed tomography scan (CT) and single photon emission computed tomography (SPECT) were performed preoperatively for 17 patients. The patients were categorized according to their CT and SPECT findings. Ten patients were included in the normal group, 7 patients were included in the CVD group. Blood flow velocity in the middle cerebral artery (MCAv) was measured by means of transcranial Doppler ultrasonography at two different arterial carbon dioxide tensions (at a high PaCO<sub>2</sub> of 45-50mmHg, at a low PaCO<sub>2</sub> of 30-35mmHg, uncorrected for body temperature) during moderate steady-state hypothermic cardiopulmonary bypass. Simultaneously cerebral oxygen consumption was estimated by relating the arteriovenous oxygen content difference to flow velocity (D-CMRO<sub>2</sub>). MCAv and D-CMRO<sub>2</sub> were expressed as percentages of the values determined at 30 minutes before cardiopulmonary bypass. In the normal group, a PaCO<sub>2</sub> of 47.4±2.5mmHg (mean±SD) was associated with an MCAv of 99.4±17.8% and a D-CMRO<sub>2</sub> of 53.4±25.5%, while a PaCO<sub>2</sub> of 33.7±1.3mmHg was associated with an MCAv of 64.3±18.1% and a D-CMRO<sub>2</sub> of 53.5±26.2%. In the CVD group, a PaCO<sub>2</sub> of 49.1±4.2mmHg was associated with an MCAv of 81.4±22.3% and a D-CMRO<sub>2</sub> of 34.0±19.4%, while a PaCO<sub>2</sub> of 33.6±1.3mmHg was associated with an MCAv of 54.7±23.8% and a D-CMRO<sub>2</sub> of 49.0±19.4%. We conclude that in patients with cerebrovascular disease cerebral blood flow is changed in response to changes in arterial dioxide tension during moderate hypothermic cardiopulmonary bypass, however a high PaCO<sub>2</sub> depresses cerebral oxygen consumption because hypercarbia may cause potentially harmful redistribution of regional cerebral blood flow away from marginally-perfused to otherwise well-perfused areas.
ABSTRACT
Between January 1980 and September 1993, 7(8.4%) of 83 patients with aortic dissection had coincident atherosclerotic true aneurysms of thoracic and/or abdominal aorta or had undergone operation of true aortic aneurysms. There was no difference in the segments of aortic dissection; 4 of 50 patinets classified as DeBakey III and 3 of 33 patients classified as DeBakey I or II, whereas the site of atherosclerotic true aneurysms was more often in the abdominal aorta than in the thoracic aorta. Five patients had undergone surgery for or had the abdominal aortic aneurysms and 2 patients had thoracic aortic aneurysms. In 2 patients who had previously undergone abdominal aortic aneurysmectomy, the dissected aorta ruptured soon after the onset of dissection. In the patients in whom the true aneurysm and the aortic dissection involve the same segments surgical treatment would be extended and complex.
ABSTRACT
A very rare case of open heart surgery associated with hereditary spherocytosis (HS) is reported. A 10-year-old girl was admitted for repair of an atrial septal defect (ASD). She was found to have HS by the microscopic findings of a blood smear and characteristic osmotic fragility, but splenectomy had not been undertaken preoperatively. She underwent successful radical operation by means of a centrifugal pump, and poloxamer 188 and haptoglobin were used during cardiopulmonary bypass for prevention of hemolysis. No significant hemolysis occurred intra- or postoperatively. Cardioplumonary bypass using a centrifugal pump appeared to be effective in this patient with HS.
ABSTRACT
In the past 11 years, we treated 41 patients with Stanford type B aortic dissection. Principally, medical therapy was carried out and surgery was performed only when complications related to the dissection occurred. Twenty two patients (53.7%) had complications, including 5 (12%) with peripheral limb ischemia, 3 (7%) with rupture, 13 (32%) with dilatation of the aorta, 4 (10%) with extension of dissection (type A dissection). Seventeen patients received surgery including palliative operation. Among 41 patients, 3 died due to aortic rupture and 2 died at surgery for type A dissection, while 4 of them had developed proximal extension of the dissection. The 5-year survival rate for all patients was 86.7±6.6%. Long term survival will improve in patients with Stanford type B aortic dissection when the operative mortality for type A dissection is reduced and sound management policies are developed.
ABSTRACT
From January of 1987 to December 1992, twelve patients (7 males and 5 females, mean age, 52.8 years) underwent emergency surgery for DeBakey type I acute aortic dissection. The surgical procedure was resection of the initial intimal tear and replacement of the ascending aorta (four patients underwent hemiarch replacement). Operative mortality was 41.7% (5/12). Three died in the operating room due to heart failure (2) and uncontrollable bleeding (1). Another two early deaths resulted from extension of the residual false lumen. All surviving patients each had a patent double-channeled aorta and aneurysmal dilatation of the false lumen was noted in 3 patients. There were two late deaths, one due to rupture of the residual false lumen and the other, to stroke during re-operation for enlargement of the residual false lumen. It is apparent from these results that in type I acute aortic dissection extensive operation such as total arch replacement is necessary.
ABSTRACT
Retrograde cardioplegia is now an alternative or adjunctive method used worldwide as a cardiac protection during open heart surgery. However, its use involves some limitation. We operated on a patient suffering from aortic stenosis associated with PLSVC. During the operation on this patient for aortic valve replacement, retrograde infusion of cardioplegic solution could not be performed because the coronary sinus was excessively dilated and prevented the balloon from occluding it. Other anomalous lesion of the coronary sinus make the retrograde infusion of the cardioplegic solution difficult and these must always be kept in mind when cardioplegia is infused from the coronary sinus.
ABSTRACT
Myocardial revascularization combined with valvular surgery were performed on 8 patients between 1986 and 1990. There were 4 males and 4 females (mean age=60.6 years). Mitral valve replacement was performed in 3 patients, aortic valve replacement in 2, and double valve replacement in 3. There were no operation death, but one late death was seen. No angina attack was evident and NYHA functional class was improved in all patients in survivers. Coronary angiography should be performed in all adult patients who have valvular disease and those with significant artery disease should undergo bypass grafting concomitant with valvular surgery.