Yasunaru Kawashima

Cox maze procedure for chronic atrial fibrillation associated with mitral valve disease.

Between April 1992 and October 1993, we combined a modified maze procedure with mitral valve repair (n = 26) or replacement (n = 36) in 62 patients with atrial fibrillation, including 16 patients undergoing reoperation. Associated procedures included aortic valve operation (n = 22), tricuspid annuloplasty (n = 28), atrial plication (n = 10), and others (n = 3). Duration of atrial fibrillation varied from 0.1 to 23 years (average 8.3 +/- 6.4 years), the f-wave voltage ranged from 0 to 0.45 mV (0.16 +/- 0.09 mV), and cardiothoracic ratio varied from 46% to 85% (64% +/- 9%). We modified the maze atriotomies to preserve the sinus node artery and used cryoablation to simplify procedures. Aortic crossclamp time was 142 +/- 25 minutes and cardiopulmonary bypass time 226 +/- 34 minutes. No early or late deaths occurred in a total of 783 patient-months of follow-up. In 52 patients (84%) who regained atrial rhythm, an atrial A-wave was detected in 84% for transtricuspid flow and in 71% for transmitral flow. One patient with sinus rhythm had an episode of transient neurologic ischemia 4 months after mechanical valve implantation. The 10 patients who remained in atrial fibrillation had preoperative fibrillation for a significantly longer time than the rest of the patients with atrial rhythm (14.8 versus 7.2 years p < 0.001) and a larger left atrial dimension (70 versus 58 mm, p < 0.01). Nonetheless, no variable alone could have predicted postoperative rhythm for individual patients. The results suggest that the maze procedure is safe and effective and therefore should be considered for patients with chronic atrial fibrillation undergoing mitral valve operations.

Surgical management of infective endocarditis associated with cerebral complications : multi-center retrospective study in Japan

To establish guidelines for the surgical treatment of patients with infective endocarditis who have cerebrovascular complications, we conducted a detailed retrospective study of 181 of 244 patients with cerebral complications among 2523 surgical cases of infective endocarditis of the Japanese Association of Thoracic Surgery. The results showed that 9.7% of all patients with infective endocarditis had associated cerebral complications: 108 (44.3%) had active native valve endocarditis, 96 (39.3%) had healed native valve endocarditis, and 40 (16.4%) had prosthetic valve endocarditis. The hospital mortality of the patients with cerebral complications was 11.0% in the group as a whole: 13.9% in active native valve endocarditis, 3.1% in healed native valve endocarditis, and 37.5% in prosthetic valve endocarditis. Diseased valves included the following aortic valve in 55.5%, mitral valve 49.8%, tricuspid valve in 1.3%, and pulmonary valve in 1.3%. In 181 patients with cerebral complications, organisms were detected as follows: gram-positive cocci in 133 (73.5% [Streptococcus in 85, Staphylococcus in 32]), gram-negative in 18 (9.9%), fungus in 11 (6.1%), and unknown in 64.6%, cerebral bleeding in 31.5%, cerebral abscess in 2.8%, and meningitis in 1.1%. Hospital mortality rate and an exacerbation rate of cerebral complications, including related death, according to the interval from onset of cerebral infarction to cardiac surgery, were as follows: 66.3% and 45.5% within 24 hours, 31.3% and 43.8% between 2 and 7 days, 16.7% and 16.7% between 8 and 14 days, 10.0% and 10.0% between 15 and 21 days, 26.3% and 10.5% between 22 and 28 days, and 7.0% and 2.3% over 4 weeks later, respectively. A significant correlation existed between the interval and the exacerbation of cerebral complications (tied p = 0.008). Preoperative risk factors affecting exacerbation of cerebral complications were as follows: (1) severity of cerebral complications (p = 0.006), (2) intervals (p = 0.012), and (3) uncontrolled congestive heart failure as indications for cardiac surgery (p = 0.014). One patient underwent a cardiac operation within 24 hours of the onset of cerebral hemorrhage and died of cerebral damage. No exacerbations occurred in 10 patients who underwent their operation between 2 and 28 days. Nevertheless, exacerbations occurred in 19.0% of patients whose operation was done more than 4 weeks later. These data suggest that cardiac operations can be done safely 4 weeks after cerebral infarction, and if the delay is more than 2 weeks, the exacerbation rate will be around 10%. The risk of progression of cerebral damage is still significant 15 days and even 4 weeks after cerebral hemorrhage.

The mechanism of discordant xenograft rejection.

The mechanism of discordant xenograft rejection using the guinea pig-to-rat heart graft model was studied. In this model, we found that (A) Rejection occurred rapidly, in 17.5 +/- 8.3 min (mean +/- SD) (n = 8). (B) The graft survived longer when the recipient rat was pretreated with cobra venom facter (CVF)

Mortality And Cerebral Outcome In Patients Who Underwent Aortic Arch Operations Using Deep Hypothermic Circulatory Arrest With Retrograde Cerebral Perfusion: No Relation Of Early Death, Stroke, And Delirium To The Duration Of Circulatory Arrest

OBJECTIVE Our goal was to investigate factors for mortality and cerebral outcome in patients with aneurysm of the aortic arch. METHODS From 1993 to 1996, 148 patients with aortic arch aneurysm underwent operations involving deep hypothermic circulatory arrest with retrograde cerebral perfusion. Age was 63.9 +/- 11.6 years (mean +/- standard deviation) and 52 patients were older than 70 years. Twenty-eight had acute aortic dissection. Twelve had ruptured aneurysms. Fourteen had redo operations. Seventy had aortic dissection. The aneurysms were caused by atherosclerosis in 123 patients and by other causes in 25. Median sternotomy was used in 92 and left thoracotomy in 56. Twenty-eight patients underwent replacement of the ascending aorta to the proximal arch, 62 had total arch replacement, 38 had distal arch replacement, 12 had simultaneous replacement of the distal arch and the descending aorta or thoracoabdominal aorta, and 8 had patch repair. RESULTS Fifteen (10.1%) early deaths occurred. New stroke occurred in six (4.0%) patients and transient delirium in 37 (25.0%). The duration of deep hypothermic circulatory arrest plus retrograde cerebral perfusion was 49 +/- 17 minutes, and it was more than 60 minutes in 36 patients. Patients awoke 7.5 +/- 8.2 hours after the operation. Logistic regression analysis demonstrated that risk factors for mortality were ruptured aneurysm, chronic obstructive pulmonary disease, arterial cannulation in the ascending aorta, and stroke. Risks for stroke were ruptured aneurysm and replacement of the distal arch. Risks for delirium were age older than 70 years and atherosclerotic aneurysm. Duration of circulatory arrest plus cerebral perfusion did not correlate with length of time before the patient regained consciousness. No difference was found in mortality, stroke, and delirium between patients with and those without more than 60 minutes of circulatory arrest and cerebral perfusion. CONCLUSION Prolonged (> 60 minutes) deep hypothermic circulatory arrest with retrograde cerebral perfusion was not a risk factor for mortality and stroke in patients who underwent surgery for aneurysms of the aortic arch. However, the prevalence of transient delirium necessitates further investigations.

Risks and Benefits of Combined Maze Procedure for Atrial Fibrillation Associated With Organic Heart Disease

OBJECTIVES This study sought to identify the risks and benefits of adding the maze procedure in patients with atrial fibrillation (AF) undergoing operation for underlying organic cardiac disorders. BACKGROUND Persistent AF often leaves patients symptomatic even after otherwise successful cardiac surgery. METHODS Fifty-one patients undergoing valvular operation and the maze procedure (n = 43) or repair of congenital anomalies (n = 8) combined with the maze procedure were compared with 51 patients (control group) matched for underlying diseases and procedures except for the maze operation. Each group, including 31 patients with a concomitant tricuspid annuloplasty and 12 undergoing reoperation, were similar in age, duration of arrhythmia, degree of cardiomegaly and New York Heart Association functional class. RESULTS Patients undergoing the maze procedure had longer cardiopulmonary bypass time (213 vs. 144 min, p < 0.0001), longer cardiac arrest (134 vs. 93 min, p < 0.0001) and greater blood loss with longer respiratory care (39 vs. 18 h p = 0.021) and intensive care unit stay but no mortality. No significant differences were found in catecholamine or transfusion requirements immediately after operation. Sustained AF was much less frequent in the maze group (12% at 1 year) than the control group (86%, p < 0.0001), with an average follow-up period of 32 months (range 25 to 42). Atrial contraction was documented in 41 (80%) and 40 (78%) patients for right and left ventricular filling, respectively, after the maze procedure, resulting in a significantly smaller cardiac size and improved functional capacity. Medication was discontinued in seven patients in the maze group compared with two in the control group. CONCLUSIONS Improved restoration of atrial rhythm and contraction with combined maze operation appeared to justify the increased operative time and complexity and postoperative care.

Modified Maze Procedure for Patients With Atrial Fibrillation Undergoing Simultaneous Open Heart Surgery

BACKGROUND Persistent atrial fibrillation (AF) leaves patients symptomatic and at increased risk of thromboembolism even after otherwise successful cardiac surgery. METHODS AND RESULTS To treat AF secondary to cardiac lesions requiring surgery, we combined a modified maze procedure in 101 patients simultaneously undergoing valvular procedures (87), repair of congenital anomalies (12), and other procedures (2), including 24 repeat operations. Duration of AF varied from 0.1 to 30 years (average +/- SD, 8.8 +/- 7.0 years); the f-wave voltage ranged from 0 to 0.45 mV (0.15 +/- 0.09 mV); and cardiothoracic ratio varied from 40% to 99% (63 +/- 9%). Aortic cross-clamp time varied from 75 to 229 minutes (138 +/- 31 minutes), with bypass time ranging from 119 to 326 minutes (217 +/- 42 minutes). There were two early deaths (2%), no late deaths, and one episode of transient neurological ischemic attack in follow-up ranging from 1.0 to 3.1 years, for a total of 190 patient-years. Postoperative rhythms were sinus in 83 patients (82%), junctional in 4 (4%), and persistent AF in 14 (14%), each of whom had mitral valve disease. Patients with other underlying pathology had complete recovery of atrial rhythm. A normal-sized A wave was detected in 88% for transtricuspid flow and in 73% for transmitral flow, suggesting concomitant recovery of atrial contraction. Among 36 patients without mechanical valves, 30 (83%) with atrial rhythm and contraction have been taken off anticoagulation therapy, including 10 who are free of all medication. CONCLUSIONS The results suggest that the combined approach is safe, effective, and indicated in patients who are judged capable of tolerating the procedure and likely to regain atrial rhythm.

A Method for Predicting Postoperative Lung Function and Its Relation to Postoperative Complications in Patients with Lung Cancer

We predicted the postoperative forced expiratory volume in 1 second (FEV1) with a formula based on the premise that the total number of subsegments was 42: postop FEV1 = [1 - (b - n)/(42 - n)] (preop FEV1), where n and b are the number of obstructed subsegments and total subsegments, respectively, in the resected lobe. It was assumed that b was 6, 4, and 12 in the right upper, middle, and lower lobes, respectively, and 10 each in the left upper and the left lower lobes. The obstructed subsegments, n, were obtained from the findings on bronchography or bronchofiberscopy or both before operation. The linear regression line derived from the correlation between predicted (x) and measured (y) FEV1 was y = 0.850x + 0.286 +/- 0.296 (standard error) (N = 52; r = 0.821; p less than 0.001). We calculated the predicted postoperative FEV1 in 188 patients with primary lung cancer. The predicted values were corrected with the regression equation just mentioned and then normalized by the patients height and sex (%FEV1(p,c). The correlation between %FEV1(p,c) and the surgical risk was studied. Postoperative respiratory complications were inversely related to %FEV1(p,c), and a significantly high incidence of complications (p less than 0.05) was observed in those whose %FEV1(p,c) was less than 60% of predicted normal. In aged patients (65 years old or more) without complications, %FEV1(p,c) was 67.3 +/- 18.0%; it was 52.2 +/- 12.8% in those with respiratory trouble and 53.3% +/- 9.6% in those with circulatory complications. The difference between groups with and without complications was significant (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation between cellular ATP level and bile excretion in the rat liver

The influence of the cellular level of adenosine triphosphate (ATP) in the liver on bile excretion was studied in rats. In ischemia, the cellular ATP level decreased rapidly--and, concomitantly, bile flow stopped within 5 min. Administration of L-ethionine i.p. to rats reduced the bile flow rate with decrease in the cellular ATP level. The correlation between the bile flow rate and the cellular ATP level was confirmed in a liver perfusion system. On anoxic perfusion, the ATP level and bile flow rate changed in the same manner as in ischemia. The recovery rates of both on reoxygenation decreased with increase in the anoxic perfusion period. During perfusion under oxygenated conditions, decrease in cellular ATP to various levels by infusion of various concentrations of potassium cyanide, an inhibitor of respiration, resulted in corresponding and concomitant suppression of bile excretion. Kinetic analysis of the bile flow rate revealed a Michaelis-Menten-type curve for the cellular ATP level. The apparent Kms for ATP of bile flow rate in L-ethionine-treated rat liver and liver perfused with potassium cyanide were 1.0 and 1.6 mM, and their Vmax values were 4.1 and 2.5 microliter/min/g liver, respectively. The concentrations of main bile components, such as phospholipids, cholesterol, and taurocholate increased, but their total outputs decreased with decrease in the ATP level, and returned to the normal range with recovery of the ATP level. Thus, it was shown experimentally that the extent of hepatic injury can be assessed simply by monitoring the bile flow rate, which reflects the cellular level of ATP.

Prediction of Postoperative Respiratory Failure in Patients Undergoing Lung Resection for Lung Cancer

To evaluate the correlation between predicted postoperative lung function and postoperative respiratory morbidity, 156 patients with lung cancer who underwent resection were classified into four groups based on the degree of postoperative problems: Group 1--no problems (116 patients); Group 2--retention of sputum or atelectasis requiring bronchofiberscopy two or more times (17 patients); Group 3--tracheostomy or mechanical ventilation for more than 2 days or both (14 patients); and Group 4--postoperative death (9 patients). The mean ages of Groups 2, 3, and 4 were significantly (p less than 0.05) higher than the mean age of Group 1. The predicted postoperative lung function (F) was assessed by the formula F = [1-(b-n)/(42-n)] x f, where f is the preoperative vital capacity or forced expiratory volume in one second, b is the number of subsegments of the resected lung lobe, and n is the number of subsegments obstructed by the tumor, which was assessed by the findings on the chest tomogram, on the bronchogram, at bronchofiberscopy, or a combination of these. The total number of subsegments was assumed to be 42. The predicted postoperative % FEV1 was 65.1 +/- 19.3% in Group 1,55.3 +/- 10.6% in Group 2,37.6 +/- 12.1% in Group 3, and 42.3 +/- 18.4% in Group 4. It was significantly (p less than 0.05) different between all the groups except between Groups 3 and 4. All 10 patients with a predicted postoperative % FEV1 of less than 30% were in Groups 3 and 4. We conclude that special attention to postoperative management is needed for patients whose predicted postoperative %FEV1 is lower than 30%.

The outcome and indications of the cox maze III procedure for chronic atrial fibrillation with mitral valve disease

OBJECTIVE The efficacy of the Cox maze III procedure for chronic atrial fibrillation associated with mitral valve disease is unclear, and so was evaluated in this study. METHODS In 30 patients, we applied the maze III procedure (cut and suture), except for one modification in the case of a left posterior sinus node artery. After dividing the patients into sinus rhythm and atrial fibrillation groups more than 6 months after the operation, we compared various parameters. RESULTS Sinus rhythm was restored in 27 patients (90%). One patient had atrioventricular reentrant tachycardia and needed a pacemaker for sick sinus syndrome (3.3%). The f-wave voltage in lead V1, the preoperative cardiothoracic ratio, the preoperative left atrial systolic dimension, and the duration of atrial fibrillation were 0.23 +/- 0.10 mV, 60.4% +/- 5.2%, 57.4 +/- 8.2 mm, respectively, and 5.1 +/- 4.6 years in the group with sinus rhythm, and were 0.06 +/- 0.05 mV, 77.7% +/- 10.3%, 95.3 +/- 24.0 mm, respectively, and 11.8 +/- 5.5 years in the group with atrial fibrillation. These parameters were all significantly different between the groups. Regarding atrial function, a transmitral flow A wave was detected in 66.7% and a transtricuspid flow A wave in 100%. Only the duration of atrial fibrillation had a significant influence on the restoration of left atrial function. CONCLUSION The maze III procedure was effective for atrial fibrillation associated with mitral valve disease. This procedure should be applied to patients with a cardiothoracic ratio less than 70% and a left atrial systolic dimension less than 80 mm.