A morphologic study of Carpentier-Edwards pericardial xenografts in the mitral position exhibiting primary tissue failure in adults in comparison with Ionescu-Shiley pericardial xenografts.

OBJECTIVE: We sought to investigate the durability and mechanism of the Carpentier-Edwards pericardial xenograft in the mitral position in comparison with that of the Ionescu-Shiley pericardial xenograft. METHODS: A total of 284 patients who received the Ionescu-Shiley pericardial xenograft in the mitral position between 1980 and 1984 and 84 patients who received the Carpentier-Edwards pericardial xenograft in the mitral position between 1984 and 1999 were included in the study. The freedom from reoperation rates for both graft types were determined. For morphologic study, the pathologic findings of 23 valves of 123 explanted Ionescu-Shiley pericardial xenografts with structural valve deterioration, nonstructural valve deterioration, or both were determined and compared with those of 20 explanted Carpentier-Edwards pericardial xenografts with structural valve deterioration, nonstructural valve deterioration, or both. Each pathologic finding was graded and assigned a score. Both types were matched for age at reoperation (50-75 years) and duration of valve function (8-11 years). RESULTS: Freedom from reoperation caused by structural valve deterioration, nonstructural valve deterioration, or both was significantly better for Carpentier-Edwards pericardial xenografts than for Ionescu-Shiley pericardial xenografts at 8 years after the operation (Carpentier-Edwards pericardial xenografts: 91.3% vs Ionescu-Shiley pericardial xenografts: 71.9%, P =.0061), but it was similar for both types at 12 years (Carpentier-Edwards pericardial xenografts: 43.6% vs Ionescu-Shiley pericardial xenografts: 43.6%, P =.2865). No severe leaflet tears were seen among Carpentier-Edwards pericardial xenografts. The mean area percentage of tissue overgrowth was 15.3% in Carpentier-Edwards pericardial xenografts and 3.4% in Ionescu-Shiley pericardial xenografts (P =.0001). The mean calcification area percentage was 13.6% in Carpentier-Edwards pericardial xenografts and 31.5% in Ionescu-Shiley pericardial xenografts (P =.0001). CONCLUSIONS: Tissue overgrowth on the atrial surface, ventricular surface, or both was the cause of structural valve deterioration, nonstructural valve deterioration, or both of Carpentier-Edwards pericardial xenografts in adults. This was different from Ionescu-Shiley pericardial xenograft failure, which resulted from severe calcification and leaflet tears. Organized thrombi on cusps, in addition to valve design, may have contributed to such tissue overgrowth on Carpentier-Edwards pericardial xenografts.

Modification of bicaval anastomosis technique for orthotopic heart transplantation.

A modified bicaval anastomosis technique was utilized for 4 consecutive patients undergoing heart transplantation. Instead of transecting the superior and inferior vena cavae, a strip of the posterior right atrial wall was left undivided as a bridge connecting the superior and inferior vena cavae. This minor modification perfectly prevented shrinkage and retraction of the caval tissue, thus providing easier anastomotic orientation and better estimation of the appropriate tissue length that fits well, particularly when a small donor heart was available.

Pericardiectomy for constrictive pericarditis using the harmonic scalpel.

A 35-year-old man with constrictive pericarditis underwent pericardiectomy. The pericardium was dissected with a Harmonic Scalpel (Ethicon Endo-Surgery, Cincinnati, OH). This new device has many advantages including no muscular stimulation, low heat, a smokeless field, and easy hemostasis. The Harmonic Scalpel is beneficial for dissection of thickened pericardium.

[Tricuspid valve replacement using right heart bypass in patient with liver cirrhosis].

A successful case with liver cirrhosis underwent re-tricuspid valve replacement (TVR) using right heart bypass is reported herein. A 59-year-old lady previously undergone tricuspid valve replacement with bioprosthetic valve had suffered from exertional fatigue as the feature of congestive heart failure. She also presented severe liver dysfunction owing to chronic hepatitis and cardiac liver cirrhosis. She was diagnosed with structural deterioration of bioprosthesis in tricuspid position. She underwent re-TVR with right heart bypass consisted of centrifugal pump, heparin coating circuit and blood reservoir. This system lacked of membranous oxygenator in order not to activate various kinds of chemical mediator which leads to postoperative liver dysfunction. Postoperative course was uneventful and she is doing well 1 year after the operation. Although the mortality of the TVR in the patient with cirrhosis remains still high, this new technique seems to provide better outcome in this kind of patients.

Tricuspid valve replacement with bioprostheses: long-term results and causes of valve dysfunction.

BACKGROUND: Although the clinical performance of bioprostheses after valve replacement in the aortic and mitral position has been reported, little is known of the performance of tricuspid bioprostheses. The mechanism of bioprosthetic valve dysfunction after tricuspid valve replacement (TVR) is not clear. METHODS: We reviewed 98 cases of TVR with bioprostheses. To clarify the causes of valve dysfunction, pathologic examination of the explanted valve at the reoperation was performed. RESULTS: Actuarial survival at 18 years was 68.7% +/- 5.8%. There were 12 redo TVRs. In six of the 12 cases, isolated redo TVR was performed. In the other cases, concomitant cardiac procedures were performed. The causes of prosthetic valve dysfunction were pannus formation on the cusps of the right ventricle side (four cases), native valve attachment (two cases), pannus formation + native valve attachment (two cases), sclerotic change (one case), pannus formation + sclerotic change (one case), and native valve attachment + valve infection (one case). Freedom from reoperation, structural valve deterioration, and nonstructural dysfunction at 18 years was 62.7% +/- 10.7%, 96.0% +/- 2.9%, and 76.7% +/- 8.3%, respectively. CONCLUSIONS: In our 18 years of experience, although the survival after TVR with bioprostheses is acceptable, the reoperation free rate is not satisfactory. Pannus formation on the cusps of the ventricular side seems to be a serious problem that causes bioprosthetic dysfunction in the tricuspid position.

Ten-year experience of chordal replacement with expanded polytetrafluoroethylene in mitral valve repair.

BACKGROUND: Mitral valve repair is the procedure of choice to correct mitral regurgitation (MR). Although chordal replacement with expanded polytetrafluoroethylene (ePTFE) has been widely accepted to repair anterior mitral prolapse and other difficult situations, the long-term results of the repair and the fate of ePTFE have not been delineated. METHODS AND RESULTS: From July 1988 to April 1999, 74 patients (49 males, 25 females) aged 17 to 77 years (mean age 55. 3+/-14.8 years) underwent mitral valve repair with chordal replacement with ePTFE. The follow-up period was from 6 months to 11. 3 years (mean 4.6+/-3.2 years). The causes of MR were degenerative in 65 patients (88%) and infective in 9 (12%). Three patients had active infective endocarditis. Valve lesions were anterior in 35 patients, posterior in 10, and both anterior and posterior in 29. Various procedures for plasty of leaflets were necessary in 37 patients (50%). Atrial fibrillation was associated in 38 patients (51%), and the maze procedure has been performed in a selected group of 30 patients (41%) since July 1992. There was 1 in-hospital death (1.4%) and 3 late cardiac deaths (4.1%). More than moderate MR developed in 12 patients (17%) during the follow-up period. Three of these patients required early reoperation within 1 year due to hemolysis. Two patients underwent mitral valve replacement at 6 and 8 years after repair, respectively. The actuarial reoperation-free rates at 5 and 10 years were 94.3+/-2.8% and 81.7+/-9.1%, respectively. Sinus rhythm was restored in 21 patients (70%) with the maze procedure. There was only 1 thromboembolic episode (0. 3%/patient-y) in a patient with atrial fibrillation who did not undergo the maze procedure. Event-free survival rates as assessed by the freedom from cardiac death, thromboembolism, reoperation, and anticoagulation-related hemorrhage at 5 and 10 years were 91.3+/-3. 4% and 71.6+/-9.7%, respectively. There was no relationship between recurrent MR and the change of ePTFE. Structural analysis of the ePTFE resected during reoperation revealed no calcification and showed remaining flexibility and pliability. Protein infiltration was observed in the ePTFE, and collagenous proliferation was recognized at the site of fixation to the valve leaflet and the papillary muscle. The surface of the ePTFE was completely endothelialized, which may induce antithrombogenicity. CONCLUSIONS: The long-term durability and biological adaptation of ePTFE as artificial chordae for mitral valve repair of MR were proved for >10 years.

Mitral valve plasty in systemic lupus erythematosus in the setting of antiphospholipid syndrome.

The first case was of a 27-year-old female, who was diagnosed as having mitral valve stenosis with regurgitation, systemic lupus erythematosus and antiphospholipid syndrome at her previous pregnancy. We performed mitral valve plasty, which included open mitral commissurotomy and Kay's annulo plasty. The second case was of a 53-year-old female, who was diagnosed as old myocardial infarction, mitral regurgitation, systemic lupus erythematosus and antiphospholipid syndrome. She underwent mitral valve plasty and coronary artery bypass grafting. Both cases were treated by administration of methylpredonisolone and heparin perioperatively to avoid thrombosis and aggravation of systemic lupus erythematosus. Both patients showed good postoperative outcome without complications. We consider that it is important to perform the plasty as far as possible, and to administer effective anticoagulation treatment to prevent complications for patients in the setting of systemic lupus erythematosus and antiphospholipid syndrome.

Valved conduit operation for aortic regurgitation associated with Behçet's disease.

OBJECTIVES: Aortic regurgitation associated with Behçet's disease is rare, and prosthetic valve detachment after aortic valve replacement is one of the most serious complications reported. We have investigated the surgical results of valved conduit operation in 8 patients. METHODS: Between 1987 and April 1999, 8 patients underwent surgery. There were 7 males and 1 female, and their ages ranged from 33 to 60 years (mean, 48 +/- 10 years). The valved conduit procedure was a modified Bentall operation. RESULTS: One patient died of arrhythmia during the hospital stay. The follow-up period in the other 7 patients ranged from 1 to 138 months after surgery (mean, 74 months). None of these 7 patients died during the follow-up period. Valve detachment needing redo-operation occurred in 1 patient, and he underwent a valved conduit operation again. CONCLUSIONS: Valved conduit reconstruction is indicated in patients with aortic regurgitation caused by Behçet's disease, in whom prevention of valve detachment is difficult even by current valve fixation methods.

Cardiac transplantation under new legislation for organ transplantation in Japan: report of two cases.

During the past 2 years since new legislation for organ transplantation from brain-dead donors came into effect in Japan, 3 cardiac transplants have been carried out, 2 of which were performed at the National Cardiovascular Center (NCVC). The recipient cases were 46- and 25-year-old male patients who suffered from end-stage dilated cardiomyopathy and had been listed for cardiac transplantation in the Japan Organ Transplantation Network as status I candidates. The first patient was supported by the use of a paracorporeal air-driven left ventricular assist device of the NCVC type, and had a moderate degree of renal and hepatic dysfunction at the time of transplantation. Donor hearts were transported from distant hospitals (Tokyo and Miyagi prefecture) and the transportation time was 1 h 33 min and 2h 4 min, respectively. The operation was performed by the standard technique (Lower-Shumway) in the first patient and by the bicaval anastomosis technique in the second patient. Reperfusion of the transplanted heart was performed retrogradely through the coronary sinus utilizing leukocyte-depleted blood with a gradual increase in temperature. Total ischemic time was 3 h 34 min and 3 h 35 min, respectively. Weaning from the cardiopulmonary bypass was easy and uneventful in each patient. Immunosuppressive therapy was conducted with OKT-3 induction in the first patient because of the coexisting renal dysfunction and with a triple immunosuppressive regimen for both patients. Routine endomyocardial biopsy showed acute rejection of less than grade Ib, and the patients were discharged on the 65th and 46th postoperative day, respectively. At present, both patients are in the NYHA class I state and are ready to return to work. The uneventful recovery seen in these patients shows the advances made in transplant medicine, including the progress and improvement of immunosuppressive therapy, surgical techniques, myocardial protection, and detection and treatment of infection. Further efforts are required to fully establish the cardiac transplantation program in Japan.

Surgical considerations of occlusive lesions associated with Takayasu's arteritis.

OBJECTIVE: Takayasu's arteritis is an inflammatory vascular disease of unknown etiology that affects the aorta and its main branches, requiring surgical intervention due to occlusive lesions. We studied early and late surgical results. METHODS: Between 1979 and December 1998, 46 patients--1 man and 45 women aged 15 to 72 years (mean: 46 +/- 13 years)--with occlusive lesions caused by Takayasu's arteritis underwent surgery. Preoperative steroids were administered to 22 patients having inflammation. Diagnosis indicating surgery included obstructive cervical vessel disease in 13 patients, obstructive coronary artery disease in 19, aortic coarctation in 15, and abdominal branch stenosis in 3. Surgical procedures involved bypass grafting in 31 (cervical vessel bypass in 13, ascending-abdominal aortic bypass in 4, axillary artery-abdominal aortic bypass in 10, descending-abdominal aortic bypass in 1, abdominal branch bypass in 3), coronary artery bypass grafting in 10, and coronary ostial endarterectomy in 9. RESULTS: Four (8.7%) died during hospitalization. Follow-up ranged from 1 to 240 months (mean: 117 months). Eight suffered late deaths and 6 patients died of cardiovascular problems. The total actuarial survival rate was 76.2% at 5 years and 70.5% at 10 years. CONCLUSIONS: Steroid therapy before and after surgery appears to affect the overall prognosis positively in patients with Takayasu's arteritis.

[An experience with the Ross operation utilizing cryopreserved pulmonary homografts procured by and stored in our homograft valve bank].

Eight patients, 4 males and 4 females ranging in age from 10 to 54 years (mean 27 +/- 13 years) underwent the Ross operation using a cryopreserved pulmonary homograft harvested by and cryopreserved in our institutional "Tissue Bank". Seven patients had a congenital bicuspid aortic valve and 3 patients had had healed infective endocarditis of the aortic valve. Four young female patients wanted to have a baby after operation. The Ross procedure was carried out utilizing aortic root replacement techniques in all patients. All patients survived and are currently in NYHA class 1, but 2 cardiac events occurred in 2 patients during the mean follow-up term of 29 +/- 19 months. The one was the anastomic stenosis between the homograft and distal pulmonary artery treated by balloon dilatation and the other was ventricular tachycardia eventually managed by the insertion of an ICD. Pulmonary autograft valve regurgitation is present in 3 patients, but it is not progressive up to the present time. Pulmonary homograft valves function well in all patients. The Ross operation for adolescents and young adults should become more popular along with more easy availability of homograft valves based upon the establishment of the "Homograft Valve Bank" system in Japan.

Preservation of the right atrial appendage improves reduced plasma atrial natriuretic peptide levels after the maze procedure.

OBJECTIVES: The present study was conducted to determine whether preservation of the right atrial appendage lessens the decrease of plasma atrial natriuretic peptide levels after the maze procedure and whether the increase of plasma atrial natriuretic peptides improves the ability of the kidneys to excrete the fluid load after the operation. METHODS: We evaluated 42 patients who underwent the maze procedure. The right atrial appendage was preserved in 22 patients but not in 20. Blood samples were obtained before and after the operation for measurement of atrial natriuretic peptides. To evaluate the influence of atrial natriuretic peptides on the ability of the kidneys, we also measured body weight, fluid balance, and the doses of furosemide and dopamine administered after the operation. RESULTS: The restoration to sinus rhythm at 1 month after was comparable in the two groups. Plasma atrial natriuretic peptide levels significantly increased after the operation in patients in whom the right atrial appendage was preserved (1 day after: 23.4 +/- 17.8 vs 3 days after: 42.7 +/- 23.6 and 7 days after: 36.3 +/- 23.7 pg/mL, P <.05) but not in patients in whom the right atrial appendage was not preserved (1 day after: 20.0 +/- 19.6, 3 days after: 28.5 +/- 19.3, and 7 days after: 23.0 +/- 16.1 pg/mL). Furthermore, plasma atrial natriuretic peptide levels were significantly lower in patients in whom the right atrial appendage was not preserved than in patients in whom the right atrial appendage was preserved at 3 and 7 days after the operation. The fluid balance during the first 7 days of the postoperative period was comparable in the two groups, although the total dose of dopamine used in the same period was significantly smaller in patients in whom the right atrial appendage was preserved than in patients in whom the right atrial appendage was not preserved (155.3 +/- 119.0 vs 244.9 +/- 129.0 microg/kg, P <.05). CONCLUSIONS: The present study showed that preservation of the right atrial appendage lessens the decrease of plasma atrial natriuretic peptide levels after the maze procedure and that increased plasma atrial natriuretic peptides may improve the ability of the kidneys to excrete the fluid load after the operation.

Strategies for CABG patients with carotid artery disease and perioperative neurological complications.

Postoperative neurological complications not only increase morbidity and mortality, but also prolong hospital stay and elevate hospital costs. From 1995, carotid artery duplex scanning (CADS) has been performed in our hospital as screening for cerebrovascular disease in patients undergoing nonemergency coronary artery bypass grafting (CABG). This study was designed to evaluate the usefulness of our strategy for preventing stroke during CABG. Between 1995 and 1997, 179 patients underwent isolated CABG. Of the nonemergency CABG patients, 146 underwent preoperative CADS. Three patients underwent a combined carotid endoarterectomy (CEA)/CABG procedure. One hundred and thirteen patients were men (77.3%), and the median age was 64, with a range of 39-82 years. The mean graft number was 2.7 +/- 0.9. Previous neurological events had occurred in 12 patients. Forty-five patients (30.8%) had abnormal CADS findings. Two (1.4%) of these patients had carotid stenosis > or = 90% in area, and five had total occlusion of the carotid artery. When the risk factors were evaluated, age and previous cerebrovascular disease (CVD) were found to be significantly higher in the group with abnormal CADS findings (P = 0.0012 and P = 0.0312). On multivariate analysis, the predictor of abnormal CADS findings were age and previous CVD (P < 0.01 and P < 0.05). Six patients (3.3%) developed postoperative stroke due to emboli (five cases) or perioperative hypoperfusion (one case). Three patients who underwent the combined CEA/CABG procedure did not suffer from any neurological complications. Preoperative screening by CADS is helpful for evaluating the presence of carotid artery disease in patients undergoing CABG. Further investigations to clarify the carotid hemodynamics are important, and synthetic assessment will be required to determine the most appropriate operative strategy.

Conventional coronary artery bypass grafting in patients with total occlusion of the internal carotid artery.

The number of patients with coexisting disease of the coronary and carotid arteries is increasing. Patients with total occlusion of the carotid artery may have a higher risk of stroke during cardiopulmonary bypass surgery and in the perioperative period. We report our results for coronary artery bypass grafting (CABG) in patients with total occlusion of the carotid artery. We examined 269 patients who underwent carotid artery duplex scanning (CADS) before CABG between November 1995 and January 1998. Among them, 11 patients (4.1%) had total occlusion of a carotid artery. Four patients underwent elective CABG and five underwent emergency CABG. One patient underwent anastomosis of the superficial temporal artery to the middle cerebral artery (STMC) and one patient underwent a combined CABG and carotid endoarterectomy (CEA) procedure. A transient neurological event occurred in only one patient (9.1%). The other patients recovered uneventfully. Our results suggest that CABG can be performed without stroke in patients with total unilateral occlusion of a carotid artery using our strategies.

[Maze procedure for a lone atrial fibrillation].

Between 1992. 2 and 1997. 12, the maze procedure for lone fibrillation or flutter (lone af) was performed in 8 patients including 2 patients with a sustained atrial fibrillation, 5 patients with a paroxysmal atrial fibrillation and 1 patient with a sustained atrial flutter. All patients had suffered from a drug resistance lone af which induced sever symptom that is the dyspnea, palpitation and fatigue. Therefore patients requested to receive the maze procedure, and they agreed with the informed concent. After the maze operation, the normal sinus rhythm was recovered in 7 of 8 patients (87.5%). In only 1 patient, a paroxysmal atrial fibrillation remained but his symptoms improved after surgery. So this operation is a good choice of a treatment for a drug resistance lone af.

[A case report of emergent CABG after left main trunk occlusion as complication of direct PTCA].

A 38-years-old man was transferred to our hospital because of cardiogenic shock following acute left main trunk (LMT) occlusion as a complication of direct percutaneous transluminal coronary angioplasty (PTCA), and then underwent emergent coronary artery bypass grafting. We successed his life salvage, but he suffers from very severe heart failure following extensive myocardial infarction. Though acute LMT occlusion as a complication of PTCA is rare, a proper treatment has to be started as soon as possible if it occurs. We must make the systems of support for the emergencies among the surrounding hospitals.

Surgery for aortic regurgitation caused by Behcet's disease: a clinical study of 11 patients.

Surgical treatment for aortic regurgitation (AR) caused by Behcet's disease is difficult due to the need to manipulate fragile, inflamed tissue. Valve detachment following aortic valve replacement (AVR) and suture detachment are serious postoperative complications. We investigated the surgical results in 11 patients. Between 1981 and July 1999, 11 patients, 9 males and 2 females, with AR caused by Behcet's disease underwent surgery. The age of these patients ranged from 33 to 60 years (mean, 45+/-8 years). The surgical procedures for AR were AVR in six patients and valved conduit operation in five patients. No patient died during the hospital stay. In a follow-up period ranging from 3 to 204 months (mean, 93+/-64 months) two patients died. Prosthetic valve detachment or suture detachment necessitating redo-operation occurred in four patients (36%) who then underwent a valved conduit procedure as a reoperation. Prosthetic valve detachment was higher in patients with AVR than in patients with a valved conduit operation. Valved conduit reconstruction is indicated in patients with AR caused by Behcet's disease in whom prevention of valve detachment is difficult even by current valve fixation methods.

Maze procedure for atrial fibrillation associated with atrial septal defect.

BACKGROUND: Atrial fibrillation (AF) is a relatively common complication in elderly patients with an atrial septal defect (ASD). However, use of the simultaneous maze procedure for AF associated with ASD remains controversial. We examined the efficacy and risk of the use of the maze procedure in these patients. METHODS AND RESULTS: Between March 1992 and April 1997, 26 patients underwent the maze procedure as a concomitant operation with ASD closure (maze group). Kosakai's modified maze procedure was performed in 17 patients, the modified Cox maze II or III procedure was performed in 6, and the restrictive right-sided maze procedure was performed in 3. The mean +/- SD age at surgery was 58.2 +/- 9.1 years. The mean +/- SD duration of AF was 7.8 +/- 8.5 years. The mean +/- SD left atrial dimension was 47 +/- 9 mm, and 24 patients (92%) had a larger-than-normal (> 35 mm) left atrium. The mean +/- SD follow-up period was 2.7 +/- 1.7 years. There were no hospital or late deaths. There was no thromboembolic episode in the late follow-up period. Sinus rhythm was regained in all patients who underwent conventional the right- and left-sided maze procedure except for 1 patient. However, 3 patients who underwent the restrictive right-sided maze procedure showed a return to AF rhythm. The atrial A wave was detected with the use of pulsed Doppler study in all patients who had a restored sinus rhythm. During the same period, 45 patients who were > 40 years old and without AF underwent only ASD closure (control group). The incidence of reopening the chest for bleeding was significantly (P = 0.046) higher in the maze group (12%) than in the control group (0%). Paroxysmal AF more frequently (P = 0.023) occurred in the control group (18%) than in the maze group (0%). CONCLUSIONS: These results suggest that the standard maze procedure should be considered in patients with AF associated with ASD. The restrictive right-sided maze procedure was not reliable, probably due to preoperative enlargement of the left atrium.

[Surgical treatment for prosthetic valve endocarditis].

From April 1993 to May 1997, 21 patients underwent surgical treatment for prosthetic valve endocarditis (PVE). There were 13 males and eight females aged from 46 to 79 years old (mean 62 years). There were four cases of early PVE (onset of PVE within 60 days from previous valve replacement), and 17 cases of late PVE (after 60 days). The predominant organisms were Staphylococcus epidermidis (eight cases), Staphylococcus aureus (two cases), MRSA (one case), streptococcal species (three cases), Candida (two cases), Pseudomonas cepacia (one case) and Enterococcus (one case). The predominant organisms were identified in 16 of 20 cases by preoperative blood culture, and in 11 of 20 cases by intraoperative tissue culture, and in 19 cases in all. There were four cases of preoperative cerebral complications, and three cases resurged. The hospital mortality rate was 24% (five patients). Reoperation was required in four patients for recurrence of PVE. Autopsy was performed in four of five patients. Intramyocardial abscess was detected in three patients. Earlier diagnosis and earlier surgical treatment could prevent emboli due to vegetations, which might cause catastrophic results, and could achieve better outcomes. Identification of the predominant organisms, especially from operative tissue cultures, is required.

Improved success rate of the maze procedure in mitral valve disease by new criteria for patients' selection.

OBJECTIVE: We have carried out the maze procedure for atrial fibrillation (AF) as a combined operation with mitral valve surgery in a consecutive fashion until December 1994 (period 1). Therefore, the success rate in sinus rhythm conversion remained unsatisfactory. We have selected the patients according to arbitrarily decided new criteria since January 1995 (period 2), and examined the results prospectively. METHODS: Between May 1992 and February 1997, we carried out the maze procedure in 220 patients as a combined operation with mitral valve surgery. During period 2, we carried out the maze procedure in 63 cases who satisfied all the new criteria (voltage of f-wave in V1 lead > 0.1 mV, cardiothoracic ratio (CTR) < 70%, LA dimension < 70 mm), and 37 patients out of these criteria. Success was defined as sinus rhythm restoration without sick sinus syndrome. RESULTS: There were 4 hospital deaths (1.8%) and 4 late deaths (1.8%). Success rate was significantly (P = 0.0089) higher in period 2 (82%) than in period 1 (65%). Success rate was significantly higher in patients within criteria than out of criteria both in period 1, period 2, and total (77 versus 48%, P = 0.018; 90 versus 66%, P = 0.004, and 83 versus 55%, P = 0.0001). CONCLUSION: The maze procedure is highly reliable when combined with mitral valve surgery if patients are selected properly.