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.

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.

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.

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.

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.

Appropriate indications for the use of a percutaneous cardiopulmonary support system in cases with cardiogenic shock complicating acute myocardial infarction

Percutaneous cardiopulmonary support (PCPS) is now available for hemodynamic support in patients with cardiogenic shock, but there are no guidelines for its use. The present study determined the appropriate indications for the use of the PCPS in patients with cardiogenic shock complicating acute myocardial infarction (AMI). Sixty-four consecutive patients with cardiogenic shock complicating AMI had hemodynamic support with an intraaortic balloon pump (IABP; n=38) and/or PCPS (n=26). The shock score (0-15) was calculated immediately before starting these support systems to quantify the severity of shock. Multivariate logistic regression analysis determined the clinical factors affecting in-hospital mortality. The relationship between in-hospital prognosis and the shock score was also examined in the 2 groups. The most significant factor related to the in-hospital prognosis was the shock score (p=0.0007; OR 2.16, 95% CI: 1.37-3.39). Another related factor was revascularization; however, this relationship did not reach statistical significance (p=0.069; OR 0.06). Among the 13 cases whose shock score was 4-8 (moderate shock), 5 survived in the PCPS group, but only 1 of 19 patients survived in the IABP group (p<0.05). None of the patients in either group whose shock score was more than 9 survived. The severity of shock is the most reliable independent predictor of in-hospital mortality in patients with cardiogenic shock complicating AMI. Using PCPS in patients with moderate cardiogenic shock may improve their in-hospital survival, but it must be used before the shock becomes severe.

[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.

Long-term pathological changes of expanded polytetrafluoroethylene (ePTFE) suture in the human heart

Expanded PTFE (ePTFE) sutures have been used widely as a mitral chordal substitute. We present a structural analysis of ePTFE sutures implanted as artificial chordae for 7.5 years and 8.6 years in patients with mitral regurgitation. No calcification was found either macroscopically or microscopically, and the ePTFE suture retained its normal flexibility. The suture was totally encapsulated with host tissues composed of dense fibrous tissue covered with endothelial cells.

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.

Esophageal perforation associated with profound shock successfully managed with hemodynamic assistance using percutaneous cardiopulmonary support

A 51-year-old man was admitted to our hospital with complaints of severe chest pain, nausea, and vomiting. These symptoms had progressed rapidly and he was in shock. It was necessary to make a correct diagnosis as early as possible. However, the hemodynamic condition of the patient deteriorated rapidly before a definitive diagnosis could be established in spite of conventional therapies. Under hemodynamic assistance with percutaneous cardiopulmonary support (PCPS), a final diagnosis of esophageal perforation was made by esophagography. Our report illustrates a new application of PCPS for highly selected cases of noncardiogenic shock as a "bridge" until an accurate diagnosis is made and a specific treatment is applied.

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.

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.

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.

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.

[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.

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.

[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.

[Surgical treatment for mitral regurgitation associated with secundum atrial septal defect]

We reviewed 25 patients who underwent a mitral valvuloplasty, from 1984 to 1996, for mitral regurgitation (MR) associated with atrial septal defect (ASD). Mean grade of MR was 2.3 +/- 0.7. The locations of mitral valve lesion were as follows; Postero-medial side of the anterior leaflet (AML) (11 patients: 44%), posteromedial side to center of the AML (7 patients: 28%), whole of the AML (5 patients: 20%), center of the AML (1 patient: 4%), posteromedial side of the posterior leaflet (PML) (1 patient: 4%). In summary, the mitral valve lesion was located in the AML in 96% patients and were seen in the postero-medial side of 96% patients. Mitral valve repair was performed as follows; chordae shortening only (3 patients: 12%), chordae shortening + Kay's annuloplasty (9 patients: 36%), Kay's anuloplasty (10 patients: 40%), using artificial chordae only (1 patient: 4%), using artificial chordae + Kay's annuloplasty (1 patient: 4%), using artificial chordae + ring annuloplasty (1 patient: 4%). In 24 patients, the grade of MR was less than 2/4 in the early postoperative period. In one patient, the grade of 3/4 MR was still remained. Reoperation were required in 2 patients, because of gradual increase of MR, 9 years and 10 years after the initial operation, respectively. In another patient, the grade 3/4 MR recurrently occurred at 6 months after the operation. He has been well maintained medically. In all 4 patients who had more than the grade 3/4 MR postoperatively, the annuloplasty was performed with Kay's method and the cause of MR was poor coaptation around the center of the AML. The mitral valve lesion associated with ASD seemed to be the dislocation of the AML which cause the discrepancy of the coaptation zone between both leaflets, without any prominent prolapse and chordae elongation. We put a particular emphasis on that the mitral valve repair should be performed with the recognition of the etiology of the mitral valve lesion. Especially, if the lesion extends around the center of the AML, sufficient coaptation area of both leaflets at the center of the AML should be obtained by anuloplasty.

[Indications for and limitations of minimally invasive cardiac surgery with the lower ministernotomy approach]

The chief benefits of small skin incisions are reduced patient discomfort, accelerated recovery, and cosmetic satisfaction without compromising the quality of surgery. Since April 1997, the lower ministernotomy approach without femoral cannulation has been performed in 43 patients in the authors' institutions. The indications for this approach were initial single valve surgery and secundum-type atrial septal defect. Cases of aortic valve regurgitation that could be repaired, and aortic stenosis that necessitated annular enlargement were excluded. Among patients with mitral valve disease, those with chronic atrial fibrillation were excluded frpm undergoing the Maze procedure and those reguiring chordal reconstruction for anterior leaflet were also excluded. Mitral valve repair for mitral regurgitation was performed in 8 patients, and open mitral commissurotomy in 2. Mitral valve replacement was performed in 3 patients and aortic valve replacement in 13. Closure of an atrial septal defect was carried out in 18 cases. An approximately 10-cm median skin incision was made, and a ministernotomy with a lower semitransverse division (inverted L-shape) was carried out. Cardiopulmonary bypass was initiated with ascending aortic cannulation and right-angled venous cannulae in the superior and inferior vena cava for mitral valve disease. Single venous cannulae from the right atrial appendage was used for aortic valve disease. Surgery was performed with mild hypothermia and intermittent tepid blood cardioplegia with diltiazem. A rigid 30-degree angle scope held by a videoscope holder with a flexible arm was used for mitral valve surgery. There were one hospital death due to perioperative myocardial infarction and pulmonary embolism. There was one reopening for bleeding which resulted in methicillin-resistant Staphylococcus aureus mediastinitis. However, the patients was discharged after rectal muscle flap repair. There was one reoperation for mitral valve repair due to hemolysis. The improvement of surgical instruments and materials will further facilitate this procedure.

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.

Survival using percutaneous cardiopulmonary support after acute myocardial infarction due to occlusion of the left main coronary artery--a report of two cases

Two cases of acute myocardial infarction due to an occlusion of the left main coronary artery (LMCA) are presented. Their cardiogenic shock was successfully treated with percutaneous cardiopulmonary support (PCPS), in addition to reperfusion therapy and an intraaortic balloon pump. The 2 patients were able to be weaned from PCPS and discharged from hospital. It is suggested that the early use of PCPS may be life-saving in patients with myocardial infarction due to the occlusion of the LMCA who have progressed to cardiogenic shock.

Recovery of cardiac function by long-term left ventricular support in patients with end-stage cardiomyopathy

Effects of long-term left ventricular (LV) support on end-stage cardiomyopathy patients is unclear. We applied our LV assist system (LVAS) to six heart transplant candidates, aged 17 to 49, with dilated cardiomyopathy, including one dilated phase hypertrophied cardiomyopathy. LVAS was installed between the left atrium and the ascending aorta, and the pump was positioned parecorporeally. In all patients, their general condition improved, and their pump flows were kept at 4 to 5 L/min. Exercise was started after stabilization of their general condition under constant pump flow. Natural heart size and function were examined by echocardiography. In the beginning of assist, all patients showed impaired cardiac function and LV dilation. During LV assist, systolic function measured by ejection time improved in all patients. Left ventricular end-diastolic dimension (LVDd), showed a remarkable decrease in two patients, who were weaned from LVAS after 3 months of support. They are doing well more than 1 year and 3 years after removal; peak VO2 levels (ml/min/kg) were 30 at 1.2 years and 27 at 2.7 years after removal. In the other four patients, however, LVDd had no remarkable changes, and three could not be weaned from LVAS. The last was discontinued from LVAS after 5 months of support because of infection and died 2 months after removal. From this experience, long-term LVAS may provide the chance for recovery of the natural heart in patients with end-stage cardiomyopathy. The patients whose hearts showed remodeling were able to be weaned from LVAS, and their heart function maintained in good condition for several years.

[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.

[Experience of weaning from left ventricular assist system in an acutely-ill patient with dilated cardiomyopathy and severe left ventricular dysfunction: a case report]

A 21-year-old man with dilated cardiomyopathy recovered from terminal heart failure with the long-term use of the left ventricular assist system (LVAS). His heart failure was refractory to maximum medical therapy including beta-blockade and intravenous catecholamines. Application of LVAS restored renal and hepatic function and even cardiac function. Left ventricular size decreased from 79 to 57 mm, and cardiac index increased from 1.6 to 2.2 l/min/m2. After 6 weeks of LVAS application, he could walk in the ward and could start exercise on a bicycle ergometer 3 months after. Ninety-five days after implantation, the LVAS could be removed. His general condition remained good and stable for more than a year after the removal of the LVAS. Timely application of LVAS seems to be one of the most important factors for successful circulatory support. Detailed criteria for LVAS application are not established yet.

Long-term results of artificial chordae implantation in patients with mitral valve prolapse

BACKGROUND AND AIMS OF THE STUDY

In terms of valve-related complication and ventricular function, mitral valve repair (MVR) is superior to valve replacement. To date, chordae shortening and transposition have been used for diffuse prolapses. We have used artificial chordae implantation for MVR since 1986, and here review our long-term results.

METHODS

Pericardial strips were used in nine patients, and e-PTFE (Gore-Tex) sutures in 58. A degenerative lesion was present in 69% of cases, endocarditis in 16% and rheumatic valvulitis in 7%. Implantation of artificial chordae was indicated for treatment of diffuse prolapse. Annuloplasty was performed in patients with or without prosthetic ring.

RESULTS

Actuarial survival rate was 78% for the pericardial chordae group at nine years, and 94% for the Gore-Tex chordae group at eight years. Thromboembolic events occurred in two pericardial chordae patients, and three Gore-Tex chordae patients required reoperation. Freedom from reoperation was 100% for pericardial chordae after nine years and 96% for Gore-Tex chordae after eight years. Quality of life among survivors is good: 83% are in NYHA class I, 89% are free from anticoagulation, and 60% require no medication. Mitral valve orifice area, estimated echocardiographically, was similar in both groups at discharge and at follow up.

CONCLUSIONS

MVR with artificial chordae provided satisfactory valve function for up to nine years. Gore-Tex chordae are less prone to deterioration than pericardial chordae. Follow up observations support the use e-PTFE chordae to correct diffuse leaflet prolapse.

Resection of a large, high-flow arteriovenous malformation during hypotension and hypothermia induced by a percutaneous cardiopulmonary support system. Case report

The key to successful surgical resection of cerebral arteriovenous malformations (AVMs) is control of bleeding and cerebral swelling. Induced hypotension is one of the most valuable means of achieving this control. The authors introduced induced hypotension with mild hypothermia by using a percutaneous cardiopulmonary support system (PCPS) to resect a large, high-flow AVM. The efficacy and technical points of this method are discussed. The PCPS, whose entire intraluminal surface was coated with heparin, was established through a transfemoral route. During resection of the AVM, a mean arterial blood pressure of 60 mm Hg and a mean body temperature of 30 degrees C were easily maintained by regulating the flow rate of the PCPS and by blood cooling. The activated coagulation time was maintained at approximately 250 seconds with a minimum systemic administration of heparin. The authors report the case of a 30-year-old woman who presented with intraventricular hemorrhage and was diagnosed as having a large, high-flow AVM located in the left sylvian fissure. The AVM was fed by the left middle, posterior, and anterior cerebral arteries and drained by the many cortical ascending veins and the basal vein. The patient underwent surgery after hypotension and hypothermia had been induced via the PCPS method. Induced hypotension decreased the tension of the nidus and made its dissection easier. The AVM was totally resected and no hemostatic difficulties were encountered. On the basis of the authors' experience, they suggest that hypotension and hypothermia induced by using the PCPS is a powerful tool for the successful resection of large, high-flow AVMs.

Surgical treatment for prolapse of the anterior mitral leaflet

BACKGROUND AND AIMS OF THE STUDY

Mitral valvuloplasty (MVP) for the prolapse of the anterior mitral leaflet (AML) is more difficult than that for the posterior mitral leaflet. The introduction of artificial chordae (November, 1986) and the concomitant maze operation (November, 1992) were surgical 'turning points' in our 17 years' experience.

METHODS

In total, 163 surgical cases of AML prolapse based on the above turning points, and carried out between 1979 and 1996, were reviewed. These included 110 MVP and 53 mitral valve replacements. MVP was performed in only 46% (29/63) of patients before October 1986 (Group I); in 72% (42/58) of patients between November 1986 and October 1992 (Group II); and in 93% (39/42) of patients after November 1992 (Group III).

RESULTS

Reoperation was required in nine patients. The reoperation-free rate after MVP was 79% at 17 years in all cases, 82% at 17 years in Group I, 86% at 10 years in Group II and 97% at four years in Group III. Besides reoperation cases, grade 3/4 mitral regurgitation (MR), assessed by color Doppler echocardiography, was detected in seven patients. The event-free (reoperation, MR, thromboembolism) rate was 69% at 17 years in all cases, 78% at 17 years in Group I, 71% at 10 years in Group II and 92% at 4 years in Group III. A concomitant maze operation was performed in 19 of 20 current patients with atrial fibrillation. The percentage of sinus rhythm after operation in Group I, II and III was 53%, 60% and 84%, respectively.

CONCLUSIONS

During 17 years' experience, mortality and morbidity after MVP for AML prolapse were satisfactory. With the use of artificial chordae, we have been able to perform MVP in more than 90% of current patients with AML prolapse. Further, a concomitant maze procedure could provide a higher incidence of postoperative sinus rhythm.

[Extensive indication of mitral valvuloplasty for non-rheumatic mitral regurgitation and postoperative QOL]

Between January 1993 and June 1996, 108 patients with non-rheumatic mitral regurgitation (MR) underwent surgical treatment. Mitral valvuloplasty (MVP) was performed in 94 patients (87%) and mitral valve replacement (MVR) was performed in 14 patients. The patients were reviewed based on the location of the prolapse, active endocarditis, and re-valvuloplasty. The proportion of MVP patients to the total number of cases was 92%, 96% and 94% for prolapse of the anterior mitral leaflet (MVP: n = 22), the posterior mitral leaflet (n = 47) and of both leaflets (n = 15), respectively; it was 60% and 33% in the patients with active infective endocarditis (n = 3) and in reoperation cases (n = 3). Reoperation was required in 2 patients. Other than reoperation cases, 3/4 grade MR was detected by color Doppler echocardiography in 6 patients although they were asymptomatic. Thromboembolism occurred in 3 patients. The event-free rate at 42 months was 80.4%. Concomitant maze procedure was performed in 36 of 39 patients with atrial fibrillation and normal sinus rhythm was obtained in 25 of the 36 patients. Only 6 patients received warfarin anticoagulation after MVP. In current cases with non-rheumatic MR, the MVP could be performed in 87% of all patients and in 94% of the patients with simple prolapse, regardless of the prolapse area. Concomitant maze procedure might provide a better quality of life after MVP.

Choice of replacement valve in the elderly

BACKGROUND AND AIMS OF THE STUDY

Little comparative information exists on the outcome of the valve replacement with bioprostheses or mechanical valves in the elderly. This study was carried out to make such a comparison.

METHODS

Follow up data were examined from 219 patients aged > or = 65 years who underwent aortic and/or mitral valve replacement using bioprosthetic (n = 67) or mechanical valve (n = 152) between April 1979 and December 1993. The mean follow up periods were 6.3 +/- 2.8 years after bioprosthesis and 4.9 +/- 2.1 years after mechanical valve implantation.

RESULTS

Although the actuarial rate of structural deterioration was higher in patients with bioprosthetic valves than in those with mechanical valves (58% versus 100% freedom at 10 years after surgery, p < 0.01), no such prosthesis-related difference was seen in the subgroup of patients aged > or = 70 (100% versus 100% at nine years, p = N.S.). The actuarial rate of major bleeding was higher after mechanical valve implantation than after bioprosthetic valve placement (90% versus 100% freedom at 10 years, p < 0.05); this lower rate with bioprosthetic valves was maintained in patients aged > or = 70 (78% versus 100% at nine years, p < 0.05). There were no significant differences in the incidences of thromboembolism and bacterial endocarditis between the two valve types.

CONCLUSIONS

Structural degeneration of bioprosthetic devices was a major problem in patients aged 65-70 years, but it was essentially negligible in those aged > or = 70 years. Anticoagulant-related bleeding was a major problem with mechanical valves in both age groups. Therefore, for patients older than 70 years, valve replacement with a bioprosthesis appears to be the method of choice.

Surgical management of Behçet's aortitis: a report of eight patients

BACKGROUND

Behçet's aortitis is one of the most severe manifestations of Behçet's disease. However, there have been few reports of this rare entity. This article we describe our experience with surgical treatment of Behçet's aortitis in 8 patients.

METHODS

From May 1978 to February 1995, we operated on 8 patients with Behçet's aortitis. All patients were followed up for a total of 54.4 patient-years (mean, 6.8 years).

RESULTS

There were no operative deaths, but 1 patient died in the hospital of ventricular fibrillation. Another death occurred as a result of pseudoaneurysm rupture 10 months after operation. Fourteen operations were performed on eight patients: a second operation was performed on four patients, and a third operation was performed on two patients. The translocated Bentall procedure, a modified Bentall procedure, was performed six times. One patient required a second operation for graft detachment, but the others have done well without further surgical intervention. Aortic valve replacement was performed six times, and three reoperations were needed after aortic valve replacement.

CONCLUSIONS

The translocated Bentall procedure may be effective for Behçet's aortitis, but further investigation is necessary.

Huge aneurysm of the sinus of Valsalva following infective endocarditis in Behçet's disease

A huge aneurysm of the sinus of Valsalva with conduction disturbance as a consequence of infective endocarditis in Behçet's disease is reported. The aneurysm extended not only into the ventricular septum but also to the right atrium and ventricle, with a complicated cavity formation. We speculate that complete atrioventricular block occurred due to an enlargement of the aneurysm into the ventricular septum, leading to a direct conduction system injury. Preoperative echocardiography and aortography were insufficient to recognize the extent of the lesion; subsequent operative examination revealed the true size. At operation, it is important to understand the lesion dimensions fully in order that appropriate surgical procedures be performed.

[Aortic valve replacement with stentless porcine aortic valve]

The Toronto stentless porcine valve (TSPV) is a stentless porcine aortic valve, preserved with glutaraldehyde solution, which has been designed to maintain natural laminar blood flow and improve hemodynamic performance and enhance durability. Aortic valve replacement with TSPV was performed in seven patients. The reason for this indication was advanced age (65 years or more) in six patients and connective tissue disease in another patient. One patient required reoperation because of prosthetic valve endocarditis 4 months after implantation. There were no other valve-related complications. Echocardiographic examination of prosthetic valve function one month after surgery showed no aortic regurgitation in any patient. Transprosthetic gradient was 15.1 +/- 5.0 mmHg. Technical know-how is required for the implantation. The hemodynamic characteristics of the TSPV were excellent. Further follow-up is required to determine durability, but further extensive indication of this valve is expected as a bioprosthesis.

Rationale of the Cox maze procedure for atrial fibrillation during redo mitral valve operations

OBJECTIVE

The frequency of reoperation for mitral valve diseases with chronic atrial fibrillation has increased steadily. This study examined the rationale for using the Cox maze operation for atrial fibrillation during redo mitral valve operations.

METHODS

Between June 1992 and July 1995, we performed the maze procedure in 42 patients as a concomitant operation with redo mitral valve surgery (maze group). Associated procedures were tricuspid valve surgery in 27 patients and aortic valve surgery in 15 patients. The mean age at operation was 57.3 +/- 9.7 years, and the mean interval from the previous operation was 14.3 +/- 10.5 years. The mean follow-up period after the maze procedure was 25.5 +/- 10.8 months. Atrial fibrillation was present at the time of the previous operation in 29 patients (69%).

RESULTS

Neither hospital death nor late death occurred. Sinus rhythm was regained in 28 patients (67%), and an atrial A-wave was detected in 21 patients (50%) by pulsed Doppler study. Patients in whom sinus rhythm was restored had a shorter history of atrial fibrillation (9.0 +/- 6.0 years vs 15.9 +/- 4.6 years, p = 0.0009), a larger f-wave on lead V1 of the electrocardiogram (0.18 +/- 0.10 mV vs 0.10 +/- 0.08 mV, p = 0.017), and a smaller cardiothoracic ratio (63% +/- 8% vs 67% +/- 5%, p = 0.049) than patients with persistent atrial fibrillation. During the same period, 54 patients underwent mitral valve reoperation without the maze procedure (control group). The aortic crossclamp and cardiopulmonary bypass times were slightly longer (p = 0.048 and p = 0.012) in the maze group (133 +/- 28 minutes and 221 +/- 43 minutes) than in the control group (126 +/- 65 minutes and 197 +/- 78 minutes). There was no significant difference in the amount of chest tube drainage or transfusion between the two groups (890 +/- 510 ml and 2120 +/- 1600 ml, respectively, in the maze group and 840 +/- 480 ml and 2140 +/- 1760 ml, respectively, in the control group). It was not necessary to reopen the chest for bleeding significantly more often in one group than in the other (14% in the maze group and 7% in the control group), and it was possible to operate without transfusion with the same frequency in the two groups (17% in the maze group and 20% in the control group).

CONCLUSION

These results suggest that the maze procedure should be considered in selected patients who have a high possibility of regaining sinus rhythm during redo mitral valve operations.

Factors affecting rhythm after the maze procedure for atrial fibrillation

BACKGROUND

The maze procedure failed to abolish atrial fibrillation (AF) in 14% of patients with underlying organic cardiac lesions. Identification of contributing risk factors will improve results either by treatment of such factors or by avoidance of high-risk patients.

METHODS AND RESULTS

We analyzed 192 consecutive patients with AF undergoing three variations of the maze procedure performed simultaneously with correction of valvular diseases (n = 165), congenital anomalies (n = 19), isolated AF (n = 7), and ischemic disease (n = 1). Twenty-six preoperative factors and two postoperative cardiac size parameters were analyzed by multivariate analyses between patients with successfully ablated AF (n = 165) and those who remained in AF (n = 27) after the maze procedure. Among all factors, postoperative left atrial dimension was the most potent in predisposing patients to persistent AF. Duration of AF left atrial dimension, and cardiothoracic ratio were identified as preoperative risk factors, whereas modifications of the maze procedure and pathogenesis and location of underlying disease failed to have a significant prognostic impact on rhythm after surgery. Individual risk analysis using the three preoperative variables revealed that left atrial size reduction to normalize its dimension played a pivotal role in determining rhythm after the maze procedure.

CONCLUSIONS

Results favor earlier performance of the procedure before these risk factors develop, after which omission of the procedure or extensive left atrial plication may be appropriate. This requires further study.

Calcific degeneration of bioprosthetic aortic valves in patients receiving steroid therapy

BACKGROUND AND AIMS OF THE STUDY

Calcification of glutaraldehyde-preserved bioprosthetic valves is a frequent long-term complication of valve replacement, although the mechanism responsible for such degeneration is not clearly understood. In the current study, we investigated the calcific degeneration of bioprosthetic aortic valves in patients who had been given steroid treatment for aortitis in order to evaluate the immune response to glutaraldehyde-preserved bioprostheses.

METHODS

Ten patients who had undergone aortic valve replacement with bioprosthetic valves were studied. Their mean age was 48.4 years (range: 27 to 64 years). Aortitis was due to Takayasu disease in eight patients and to Behcet aortitis in two. The bioprosthetic valves used included bovine pericardial xenografts (n = 8) and porcine aortic valves (n = 2). The mean daily dosage of prednisone was 10.1 mg (range: 2.5 to 60 mg); mean duration of therapy was 8.0 years. The mean patient follow up, using echocardiography, was 11.5 years (range: 8.5 to 16 years). The total follow up period was 115 patient-years.

RESULTS

During follow up, three reoperations were required because of valve detachment, aortic insufficiency due to perforation of the aortic cusp, and aortic insufficiency with coronary orifice stenosis, respectively. No reoperations were required for stenotic degeneration of the bioprosthetic valves. Seven bioprosthetic valves were still functioning between 8.5 and 16 years after implantation. Calcific degeneration in two of three bovine pericardial valves that required replacing was surprisingly minimal; separation of collagen fibers in the valves by infiltration with plasma proteins was also minimal.

CONCLUSIONS

These results suggest that the calcific degeneration of bioprosthetic valves may be decreased by concomitant steroid therapy for aortitis, though further research will be required to confirm this effect and to determine the mechanism(s) involved.

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.

Valve replacement with the CarboMedics bileaflet mechanical prosthesis: clinical results at midterm

OBJECTIVE

We study the clinical midterm results of the valve replacement with the CarboMedics bileaflet mechanical prosthesis. EXPERIMENTAL DESIGN AND SETTING: Retrospective study. Institutional practice (National Cardiovascular Center, Osaka, Japan).

PATIENTS AND INTERVENTIONS

167 CarboMedics prostheses were implanted in 144 patients from April, 1990 and December, 1993. Of these, 77 patients underwent isolated aortic valve replacement (AVR), 45 patients underwent isolated mitral valve replacement (MVR), 21 patients underwent double (aortic and mitral) valve replacement (DVR), and one patient underwent triple (aortic, mitral and tricuspid) valve replacement (TVR).

MEASURES

Events were defined in accordance with the guidelines for reporting morbidity and mortality after cardiac valve operations of the Society of Thoracic Surgeons/American Association for Thoracic Surgery.

Clinical experience of percutaneous cardiopulmonary support

Recently, percutaneous cardiopulmonary support (PCPS) combined with femoro-femoral bypass without reservoir has become valued because of its quick and easy application. We developed a fully preconnected compact integrated cardiopulmonary bypass (CPB) unit (priming volume of 250 ml) with a blind pore membrane oxygenator (Kuraray Menox) for PCPS. From 1990 to 1995, PCPS was performed in 49 patients of whom 26 were weaned from support. In most cases, we applied this CICU in patients with no active bleeding (22 patients); in patients with active bleeding (n = 13), we used Medtronic's heparin-bonded close chest support pack (CCSP). Of these, PCPS was performed uneventfully for 2 h (median) in 8 elective cases; all of these patients were weaned or were switched to a left ventricular assist system (LVAS). In 8 urgent cases, such as those with low cardiac output syndrome, PCPS was performed for 4 days (median), 1 was weaned, and 2 CICU were cases switched to other procedures. In 32 cases of shock, 5 CICU patients were weaned, and 3 of them survived. Eight patients including 5 CICU patients and 1 CCSP patient were switched to operation or LVAS, and 2 CICU patients remain alive. From these data, PCPS has been shown to support the patient's circulation in the acute phase and earn time to switch to operation or LVAS; the quick and easy set-up of the CICU can improve the clinical results. The use of the Medtronic device broadened the indication for PCPS. The CCSP enlarged the indication of PCPS but could not improve the results. To improve the results, a heparin-bonded surface is desired.

[Valvular surgery in the patients more than 70 years old]

One hundred twenty-eight valvular surgeries in patients over 70-year-old were reviewed (AVR:58, MVR:38, AVR and MVR: 11, mitral valvuloplasty (MVP): 11, AVR + MVP:11, mitral valvuloplasty (MVP): 11, AVR + MVP: 8, others: 2). Concomitant CABG was performed in 7, Maze in 6, TVR in 5 and Bentall in 3 cases. Early deaths occurred in 17 patients (13%). The early mortality was 5% in AVR, 21% MVR, 18% in AVR and MVR, 0% in MVP and 38% in AVR and MVP. Late death occurred in 16 patients. Forty-three percent of the late deaths were cardiac death. The actuarial survival at 10 years was around 50% in all groups. In the aortic position, a mechanical valve was implanted in 47 cases and a bioprosthetic valve was implanted in 33 cases. In the mitral position, the mechanical valve was implanted in 37 cases and the bioprosthetic valve was implanted in 12 cases. The event free rate after AVR at 10 years was 37% in patients with the mechanical valve (3 cerebral hemorrhage, 2 PVE, 1 thromboembolism and 1 sudden death) and 46% in patients with the bioprosthetic valve (2 PVE and 1 primary tissue failure). The event free rate after MVR at 10 years was 84% in patients with mechanical valves (1 perivalvular leak, 1 PVE and 1 sudden death) and 75% in patients with bioprosthetic valves (1 PVE and 1 sudden death). Between mechanical valve group and bioprosthesis group, no statistically significance was found in the event free curve after AVR nor MVR. There was no valve related event after MVP. Considering the better durability of bioprostheses in the aortic position than in the mitral position, the presence of atrial fibrillation and necessity of warfarin anticoagulation, we conclude that a choice of a bioprosthetic valve could be acceptable in the aortic position, but may not be recommended in the mitral position.

Ten-year experience with the Carpentier-Edwards pericardial xenograft in the tricuspid position

We reviewed the cases of 66 patients who underwent 67 tricuspid valve replacements with Carpentier-Edwards pericardial xenografts between April 1985 and January 1994. Average patient age at time of operation was 52 years (range 8 to 71 years). Concomitant mitral or aortic valve replacements were performed in 46 patients. There were 10 operative deaths and 6 late deaths. Actuarial survival at 9 years was 75.4% +/- 5.7%. Prosthetic valve endocarditis occurred twice in one patient. Reoperations for tricuspid regurgitation and for concomitant procedures (maze operation and repair for leak of the mitral prosthesis) were performed in two patients. In both cases, examination of the explanted prostheses showed that the tricuspid regurgitation was the result of nonstructural dysfunction caused by fibrous pannus formation on the cusps of the ventricular side. Among the survivors, 47 patients (92%) were in functional class I or II. Prosthetic valve function was studied by color Doppler echocardiography. Among 38 patients, tricuspid regurgitation more than grade 3/4 or transprosthetic gradient more than 5 mm Hg was found in 11. One patient had right heart failure and the others had no symptoms. In 10 years of experience with the Carpentier-Edwards pericardial xenograft, mortality and morbidity after tricuspid valve replacement were satisfactory. Echocardiographic examination revealed subclinical prosthetic dysfunction in 35% of patients who were followed up for longer than 5 years, however, and we believe that these patients should receive careful follow-up.

[Anticoagulant related hemorrhage and thromboembolism after valvular surgery]

We reviewed anticoagulant related hemorrhage (ACRH) and thromboembolism (TE) in 84 patients after valvular surgery. There were 45 females and 39 males with a mean age of 51.8 years (range 30.5-71.2 years), who underwent valvuloplasty in 14, bioprosthetic valve replacements in 17, mechanical valve replacements in 13. A mean period from the operation to the event were 2.7 years (range 0.01-12.3 years). There were 25 ACRH events after one valvuloplasty, 4 bioprosthetic valve replacements, 20 mechanical valve replacements. About half of them, the prothrombin time were less than 25%, which was considered the effect of warfarin is high, and 8% of them had infective endocarditis (IE) previously. There were 59 TE events after 13 valvuloplasties, 13 bioprosthetic valve replacements, 33 mechanical valve replacements. In the patients with atrial fibrillation, TE occurred irrespective of operative procedures. And in the patients with mechanical valve, severely impaired left ventricular function and past history of IE, thrombi of left ventricule were caused of TE. It was suggested that past history of IE was a risk factor ACRH and TE, and severely depressed left ventricular function and atrial fibrillation were for TE.

[Comparison of long-term prognosis between medical therapy PTCA and CABG for multiple coronary vessel disease]

Left main trunk disease is mainly treated by CABG, on the other hand, single vessel disease is applied by Simple Medical or PTCA. These concept is widely accepted, but, there were controversies about the treatment for multiple vessel disease. The purpose of this study was to clarify the long-term prognosis of different therapeutic means for multiple vessel diseases. In our center, 3635 consecutive initial coronary angiography were done from September 1977 to December 1989. Of those, 1190 patients of multiple vessel diseases excluding those with left main trunk lesion, previous re-vascularization or acute myocardial infarction were served for this study. Double vessel disease (DVD) was 727 patients, Triple vessel disease (TVD) was 455 patients. We divided these patients into three groups according to their initial therapy. A retrospective analysis was carried out on the follow-up patients from survival rate, cardiac death free rate and cardiac event free survival rate. The cardiac death were due to acute myocardial infarction, congestive heart failure and sudden death. The cardiac event including all death, acute myocardial infarction, PTCA and CABG. The statistical analysis was done by Kaplan-Meier and Cox Proportional Hazard Model. The survival rate in DVD and TVD, Medical was significantly lower than other groups. Survival curves of CABG and PTCA was quite similar. The survival rate at 5 years was 85 (M), 89 (C) and 89% (P), and at 10 years 67,78 and 76%, respectively in DVD, and the survival rate at 5 years was 57,91 and 90%, and at 10-years, 57,77 and 78%, respectively. The cardiac death free rate in DVD and TVD showed same tendency. The cardiac event free survival in DVD, PTCA was significantly lower than other groups. This result was derived from high incidence of re-stenosis after PTCA. The cardiac event free survival rate were at 5 years 79 (M), 86 (C) and 58% (P) and at 10 years 50, 58 and 30%, respectively. In TVD, CABG was significantly higher than other groups. The cardiac event free survival rate were at 5 years 72, 86 and 63% and 10 years 42,64 and 39%, respectively. In Summary, the survival rate and cardiac death free rate of Medical were significantly lower than those of CABG and PTCA. There were no significant differences between CABG and PTCA on the survival rate and cardiac death free rate. The cardiac event free survival rate of CABG was significantly higher than that of PTCA and Medical. In multiple vessel disease, CABG will bring the best long term prognosis. Even though the cardiac events were most frequent in PTCA, it's survival rate was quite similar to CABG. So, PTCA must be thought the second best method of the therapy of multiple vessel disease.