Clinical experience with the Smeloff-Cutter aortic valve prosthesis: an 8-year follow-up study

Ball valve (Smeloff-Cutter) aortic valve replacement without anticoagulation

BACKGROUND

Because of the difficulty of permanent anticoagulation in our young population, Smeloff-Cutter ball valves have been used since 1986 at our institution for aortic valve replacement in selected patients without permanent anticoagulation therapy.

METHODS

The availability of a satisfactory follow-up system since July 1988 suggested a study of all 47 patients operated on since then and followed for a mean of 43.2 months (range, 16 to 78 months). Mean age was 26.3 years, 98% were in sinus rhythm, and 16 patients (34%) had concomitant mitral repair.

RESULTS

There were no hospital deaths. Three patients were lost to follow-up at a mean of 27 months. Four late deaths occurred (8.5%), two of them sudden, with actuarial survival at 6 years of 91% +/- 4.3%. There were a total of five embolic events (2.9%/patient-year). For isolated aortic valve replacement only, with antiaggregant therapy (n = 29), the incidence was 0.9%/patient-year. For all patients receiving antiaggregant agents (n = 43), it was 3.02%/patient-year. There were no known cases of valve thrombosis. Reoperation was required in 5 patients.

CONCLUSION

Aortic valve replacement with the Smeloff-Cutter ball valve might be a valid alternative for young patients unable to maintain regular anticoagulation.

Clinical experience with the Smeloff-Cutter prosthesis: 1- to 12-year follow-up

To determine the long-term results of aortic valve replacement with the Smeloff-Cutter prosthesis, the fate of 358 of 459 (78%) consecutive patients was determined 1 to 12 years postoperatively. There were 319 male patients (70%). Mean age at operation was 57 years (range, 15 to 84 years). Aortic stenosis was the dominant lesion in 267 patients (58%) and aortic regurgitation in 133 patients (29%). Fifty-nine patients (13%) had both aortic stenosis and regurgitation. In addition to aortic valve replacement, 93 patients (20%) had coronary artery bypass, 30 (6.5%) had mitral commissurotomy, 23 (5%) had mitral valve replacement, and 41 (9%) had other procedures. Preoperative status by New York Heart Association Functional Class was: Class I, 3 (1%); Class II, 39 (8%); Class III, 148 (32%); and Class IV, 269 (59%). Operative (30-day) mortality was 8.5% (39 out of 459). Functional improvement was obtained in all postoperative survivors: 345 (82%), Class I; 63 (15%), Class II; and 12 (3%), Class III. A perivalvular leak developed in 6 patients (1%) and subacute bacterial endocarditis in five (1%). Actuarial long-term survival was 80% at 5 years and 71% at 8 years. Thromboembolism occurred in 34 patients (9.5%). The incidence of thromboembolism per 100 patient-years for patients receiving no anticoagulants was 5.4; antiplatelet agents, 2.9; and Coumadin (sodium warfarin), 2.6. Major thromboembolism was uncommon in patients on a regimen of sodium warfarin but major morbidity from bleeding was significant.

Clinical experience with the Kay-Shiley mitral valve prosthesis: an eleven-year follow-up study

A total of 63 patients, who survived mitral valve replacement with the Kay--Shiley caged disc mitral valve prosthesis, were followed for 11 years by single clinic group to assess long-term results post valve replacement. Sixty-one patients (97%) received a muscle guard type Kay--Shiley prosthesis. All patients received oral anticoagulation therapy. The valvular damage was caused by rheumatic disease in 51 patients, infectious endocarditis in six patients, myxomatous degeneration in two patients, coronary artery disease in two patients, and idiopathic ruptured chordae tendineae in two patients. Late death occurred in 21 patients (33%); the 10-year actuarial survival was 65%. Twenty-six patients had at least one thromboembolic event, and the total number of thromboembolic events was 10.3 per 1000 patient months. Two patients developed prosthetic valve endocarditis. Both patients were heroin addicts and died of valve ring abscess. Long-term periods of clinical observation are necessary to assess the effects and benefits of prosthetic valve implantation. These data are important for comparison with other "10-years" valves.

Infection of glutaraldehyde-preserved porcine valve heterografts

Gross, histologic and ultrastructural changes associated with bacterial infection are described in four porcine valve heterografts that had been in place in patients for 6 days to 28 months. In one patient, culture of the aortic tissue tag included in the heterograft container grew Mycobacterium chelonei; however, examination of the heterograft, recovered at necropsy 6 days after implantation, revealed small colonies of bacteria that differed morphologically from mycobacteria. A second heterograft was the site of staphylococcal infection associated with extensive destruction of collagen in the leaflets. Similar destruction was observed in a third heterograft, which was found to have organisms on ultrastructural study even though bacterial cultures of the valve were negative. The fourth heterograft, from a patient who died of coronary embolism secondary to dislodgment of vegetative material, contained structures resembling lysed bacteria. Observations in these 4 patients and review of published reports of infection involving 43 other patients with porcine valve heterografts indicates that infection in these valves: (1) develops in the fibrin layer that covers the cusps, (2) can involve the collagen in the leaflets, and (3) is uncommonly (three patients) associated with valve ring abscesses.

Valve replacement in patients with active infective endocarditis

Eleven of 138 patients with infective endocarditis (IE) who underwent cardiac valve replacement for IE during a 12 1/2-year period had active IE. Eight of the 11 (all with aortic IE) had positive blood cultures within 48 hours preoperatively; six of the eight had positive Gram stains and cultures of the excised cardiac tissue. All 11 patients had Class IV cardiac functional disability (New York Heart Association classification) at the time of surgery. Staphylococci (three patients with Staphylococcus aureus and one with S. epidermidis) were the most frequent isolates. Three patients died; two of these three deaths occurred in patients who had a sudden onset preoperatively of severe aortic regurgitation and heart failure. In one patient (S. epidermidis infection) prosthetic valve endocarditis developed. Cardiac valve replacement may be performed successfully in patients with active IE even when blood cultures are positive in the immediate perioperative period. The hemodynamic status of patients with IE should be the determining factor in the timing of cardiac valve replacement, rather than the activity of the infection or the length of preoperative antimicrobial therapy. A radical surgical procedure may be necessary in patients with myocardial or aortic abscesses in whom conventional aortic valve replacement is not possible.

Thromboembolism in mitral porcine valve recipients

A low incidence rate of thromboembolism has been reported in mitral porcine valve recipients. In contrast, 5 of 22 single mitral porcine valve recipients (23 percent) followed up in our clinic for a mean of 16 months had thromboembolic events. All patients but one were receiving long-term anticoagulant therapy. One thromboembolic event resulted in death, three in permanent neurologic deficits and one in a peripheral arterial occlusion. All five patients with emboli had atrial fibrillation and left atrial enlargement. Three had thromboembolic events before porcine heart valve implantation. In addition, five mitral porcine valve recipients who were not receiving anticoagulant therapy were examined at autopsy. Thrombus was identified in the left atrium in three patients, at the tissue-valve interface (sewing ring) in two, on the porcine valve cusps in one and in the right atrium in one. Factors influencing thrombus formation such as left atrial enlargement, atrial fibrillation and a prosthetic device are present after mitral porcine valve implantation and are indications for long-term anticoagulation therapy.