Two years' clinical experience with a quadrileaflet stentless bioprosthesis in the mitral position

BACKGROUND AND AIMS OF THE STUDY: Currently available bioprosthetic mitral valves do not provide sufficient durability. A new stentless pericardial prosthesis was designed for better hemodynamic performance and reduction of stress load compared with current stented bioprostheses. METHODS: Between September 1997 and August 1999, the Quadrileaflet mitral valve (QMV) was implanted in 17 patients at our institution. Four patients had minimally invasive mitral valve replacement. Mean patient age was 62.2 +/- 16.3 years; preoperative NYHA class was 3.06 +/- 0.2; ejection fraction was 64.1 +/- 14.7%. Echocardiography was performed pre-, intra- and postoperatively, and at 3-6, 12 and 24 months follow up. RESULTS: Fifteen patients had an uneventful intra- and postoperative course. Two patients died, one from acute left heart failure at 6 h after surgery, and one on the first postoperative day after resuscitation for ventricular fibrillation. A small-sized prosthesis was implanted in four patients, medium-sized in eight and large-sized in five. The mean duration of cardiopulmonary bypass was 138.3 +/- 37.0 min; mean cross-clamp time was 91.3 +/- 26.3 min. Postoperative control echocardiography showed a mean valve orifice area of 2.5 +/- 0.4 cm2, transvalvular velocity (Vmax) was 1.6 +/- 0.4 m/s, and mean pressure gradient 3.6 +/- 2.0 mmHg. Echocardiographic evaluation after 3, 6 and 12 months showed no significant difference compared with the intraoperative data. Three patients had a minor mitral regurgitation (grade I-II). At 12 months all patients were in NYHA class I or II. CONCLUSION: The implantation technique of the QMV is more demanding, but the prosthesis is a promising alternative to conventional biological mitral valve replacement. Further follow up is needed to confirm these favorable mid-term results.     

A 25-year experience with Carpentier-Edwards Perimount in the mitral position

Data of 401 patients who underwent mitral valve replacement with the Carpentier-Edwards Perimount bioprosthesis between 1984 and 2009 were evaluated. Their mean age was 68.1 ± 10.4 years (range, 22-90 years) and 54.9% were female. The most common etiology was degenerative disease (33.2%) and 62.1% of patients had mitral insufficiency. Follow-up was 3,178 patient-years, and 96.8% complete; the mean follow-up was 8.9 ± 3.1 years. Overall survival at 25 years was 10.2% ± 3%. Late mortality was 2.48% per patient-year, and valve-related deaths occurred at 1.62% per patient-year. The actuarial freedom from reoperation due to structural valve deterioration at 20 years was 24.3% ± 2% for degenerative disease and 15% ± 1.4% for non-degenerative disease. For degenerative valve disease, the freedom from structural valve deterioration at 18-years was 39% ± 1% for recipients <60-years old and 66% ± 2% for those ≥60-years old. Our data confirm the excellent durability and low mortality associated with the Carpentier-Edwards Perimount for mitral valve replacement. The rate of calcification of the valve was unrelated to degenerative valve disease, but our findings suggest that this prosthesis gives better results in recipients ≥60-years old than in younger patients.     

Isolated replacement of a prosthesis or a bioprosthesis in the mitral valve position

The operative results of 249 mitral valvular reoperations performed in 215 patients from 1974 through 1986 were reviewed to identify groups at greater risk. Two to 4 reoperations were performed in 28 patients. The mean interval between the first and second valve procedures was 47 +/- 40 months. The most common indications for reoperation were degeneration of bioprostheses (44%) and thrombosis of mechanical prostheses (26%). Thirty patients (12%) died. This rate was significantly higher (p less than 0.02) than that for primary valve procedures performed during the same period. The mortality rate for elective reoperations was 7%. Mortality rates were higher among patients with prosthetic valve endocarditis (6 of 17 cases, 35%), in those undergoing operation on an emergency basis (19 of 82, 23%) and when tricuspid valve replacement or anuloplasty was also performed (9 of 38, 24%) (p less than 0.02). No significant correlation was found between mortality rates and the age or sex of the patients and the types of prosthesis used originally.     

Echocardiogram of the porcine aortic bioprosthesis in the mitral position

Echocardiography was performed in 10 consecutive patients who had a clinically normally functioning porcine aortic bioprosthesis in the mitral position. Strong well defined echoes were recorded from the anterior and posterior aspects of the xenograft stent. The maximal separation of the anterior and posterior stent echoes approximated the diameter of the stent at its base. The maximal excursion of the anterior stent was 5 to 10 mm (mean 7.5) with a mean systolic slope of 15 to 35 mm/sec (mean 22.2) and diastolic slope of 11 to 59 mm/sec (mean 21.5). In all 10 patients it was possible to record an anterior xenograft leaflet with anterior movement at the onset of diastole and posterior movement at the onset of systole and with appropriately steep (more than 200 mm/sec) slopes. The diastolic (E-F) slope of the anterior leaflet in 9 of the 10 patients ranged from 9 to 38 mm/sec (mean 19). In 6 of the 10 patients a posterior xenograft leaflet with a movement pattern symmetric with that of the anterior leaflet was recorded. In two patients, the central aortic leaflet was recorded with little diastolic displacement. These two patients also had mild aortic regurgitation, which was associated with diastolic shudder of the the xenograft leaflets.Echocardiography was also performed in one patient who was later shown to have a 10 cm³ thrombus on the ventricular surface of a xenograft valve. The echocardiogram in this patient revealed the following abnormalities: (1) excessive anterior stent movement and systolic slope suggesting paravalvular leak in the presence of abnormal cinefluoroscopic valve tilt, and (2) multiple dense nonhomogeneous echoes between the anterior and posterior aspects of the valve stent, with an early diastolic clear space behind the anterior stent and abnormal echoes behind the posterior stent during systole. Echocardiography therefore appears to be useful in evaluating the porcine aortic bioprosthesis in the mitral position.     

Medtronic intact porcine bioprosthesis in the aortic position: 13-year results

BACKGROUND AND AIM OF THE STUDY: The Medtronic Intact porcine bioprosthesis is a second-generation porcine bioprosthesis. This study was designed to evaluate results with this valve implanted in the aortic position at 13 years, notably with regard to the risk of structural valve deterioration (SVD). METHODS: A total of 188 patients (mean age 72.0+/-8.2 years; range: 28-89 years), who underwent aortic valve replacement between June 1987 and December 1990, was reviewed. RESULTS: Operative mortality was 9.0% (n = 17). Mean follow up per patient was 7.2+/-4.2 years (maximum 13.6 years); total follow up was 1,408.4 years. Linearized late mortality rate was 6.8%/patient-year (pt-yr) (n = 96), and the overall survival at 13 years 31.5+/-4.3%. SVD occurred in eight patients (linearized rate 0.57%/pt-yr), and freedom from SVD at 10 and 13 years was respectively 95.8+/-1.9% and 91.0+/-3.3% actuarial, and 97.3+/-1.2% and 95.5+/-1.6% actual. The mean time to onset of SVD was 7.8+/-2.8 years, and was independent of patient age at the time of implantation. Freedom from SVD at 10 and 13 years by age groups was: age < or =60 years, 76.6+/-14.8% and 60.9+/-18.0% actuarial, and 80.0+/-12.6% and 68.6+/-15.1% actual (linearized rate 3.3%/pt-yr); age 61-70 years, 96.3+/-2.6% and 92.4+/-4.5% actuarial, and 96.6+/-2.4% and 94.8+/-2.9% actual (linearized rate 0.37%/pt-yr); and age >70 years, 98.3 1.7% and 95.8+/-3.0% actuarial, and 99.2+/-0.8% and 98.3+/-1.2% actual (linearized rate 0.26%/pt-yr) (p <0.007). CONCLUSION: When implanted in the aortic position, the Medtronic Intact porcine bioprosthesis provides a low rate of SVD at 13 years. The prosthesis can be used in the aortic position in subjects aged over 60 years with a low rate of deterioration, similar to that with other second-generation bioprostheses.     

Bovine pericardial bioprosthesis in mitral position. A ten-year follow-up

BACKGROUND: The pericardial bovine prosthesis Pericarbon should offer some advantages in comparison with the former generations, because its development is focused on solving previous problems and resulted in the variation of the pericardial fixation method, of valve structure and of stent coating. This hypothesis was evaluated through a retrospective follow-up. METHODS: Between 1985 and 1989, 78 Pericarbon prostheses O 29 were implanted in mitral position by the same surgeon. All patients received warfarin for the first three months to maintain an International Normalized Ratio between 2.5 and 3.5; after which they received antiaggregant therapy indefinitely. With an average follow-up period of 7.34 years for a total of 573 patient-years, we evaluated perioperative and late mortality, late morbidity (thromboembolic and haemorrhagic events, reoperations, primary tissue failures, endocarditic events) and patient clinical conditions. RESULTS: Perioperative mortality was 1.28% (1/78), late mortality was 11.6% (9/77) with 5 valve-related deaths. 5-year survival was 93% and 10-year survival 97%. Fifteen patients required reoperation for prosthetic replacement, fourteen for primary tissue failure. There were ten minor thromboembolic events, one major event, one haemorrhage and one prosthetic endocarditis (the last two with patient exitus). After 10 years (75% of patients were in New York Heart Association class I-II. CONCLUSIONS: Besides the known better haemodynamic performance, Pericarbon bioprosthesis seems to present a survival and redofreedom curve comparable to the best porcine prosthesis, with less incidence of endocarditis, thromboembolic events and prosthesis leakage.     

Long-term results with the Xenomedica porcine bioprosthesis in the mitral position.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate our clinical experience with the Xenomedica heart valve prosthesis, a low-pressure glutaraldehyde-preserved porcine aortic valve with low-profile mounting. METHODS: Between January 1983 and July 1990, 242 consecutive patients (75 men, 167 women; mean age 59.8+/-8.0 years; range: 32-77 years) underwent mitral valve replacement with the Xenomedica prosthesis. Preoperatively, patients were in NYHA classes III (66%) and IV (26%); 94 patients (39%) had undergone previous cardiac surgery and 201 (83%) had chronic atrial fibrillation. Etiology was rheumatic in 51%, myxomatous in 7%, ischemic in 1%, endocarditis in 2%, and due to dysfunction of a previously implanted device in 39%. In total, 115 (47%) patients underwent an associated procedure. Mean follow up was 142+/-24 months (range: 2-181 months); total follow up was 2,627 patient-years. RESULTS: Early mortality was 8.2% (14 patients with low-output syndrome, three with multi-organ failure, one with stroke and two with major bleeding, 2). Late mortality was 45% (3.8%/pt-year) (84 cardiac deaths, 38 being valve-related). Actuarial survival at 5, 10 and 15 years was 69+/-3%, 52+/-3% and 38+/-4%, respectively. Actuarial estimates of freedom from structural valve deterioration (SVD) at 5, 10 and 15 years were 93+/-2%, 64+/-4%, and 25+/-9%; in almost all cases SVD occurred in progressive fashion. At 5, 10 and 15 years, estimates of freedom from thromboembolism were respectively 90+/-2%, 83+/-3% and 83+/-3%, for anticoagulant-related hemorrhage 96+/-1%, 88+/-3% and 88+/-3%, for endocarditis 96+/-1%, 94+/-2% and 94+/-2%, and for reoperation 93+/-2%, 67+/-4% and 54+/-6%. Estimates of freedom from all valve-related mortality at 5, 10 and 15 years were 87+/-2%, 80+/-3% and 75+/-4%. Multivariate analysis (Cox model) showed younger age to be a significant risk factor for reoperation. CONCLUSION: Long-term results with the Xenomedica device implanted in the mitral position appear in line with those achieved for other first-generation bioprostheses. However, incidence of primary tissue failure within 10 years was unsatisfactory. Although sudden dysfunction of the device never occurred, close monitoring of survivors is warranted.     

Malfunction of a Hancock bioprosthesis in the mitral position 24 years after initial implantation

BACKGROUND AND AIMS OF THE STUDY: Although many types of cardiac bioprosthetic valves are currently available, the major disadvantage of their use is limited durability due to progressive structural valve deterioration. Few such valves function beyond 20 years. METHODS: A 61-year-old man was admitted urgently to our institute with acute mitral insufficiency, 24 years after undergoing mitral valve replacement with a 25-mm standard Hancock porcine bioprosthesis for mitral stenosis. RESULTS: Mitral valve reoperation was performed successfully with a mechanical valve. The explanted bioprosthesis showed leaflet perforations and a commissural tear, moderate calcification on the commissures, and pannus overgrowth. CONCLUSION: The findings in this case suggest that individual patient variables, as well as the design and the construction of the valve are major determining factors in the rate of valve failure.     

Long-term follow up of the Biocor porcine bioprosthesis in the mitral position

BACKGROUND AND AIM OF THE STUDY: The study aim was to review the long-term results of mitral valve replacement (MVR) with the Biocor porcine bioprosthesis, in order to investigate patient survival and valve-related complications. METHODS: Data were presented for 546 patients (320 females, 226 males; mean age 49.2 +/- 17.1 years) who underwent MVR with the Biocor porcine bioprosthesis between March 1983 and December 2000. Preoperatively, rheumatic fever was present in 42.3% of patients. Associated procedures were performed in 179 patients (32.7%), and myocardial revascularization in 54 (9.9%). Preoperatively, 41.9% of patients were in NYHA class IV. Postoperative follow up was conducted by telephone interviews, questionnaires, or examination of hospital records. RESULTS: The hospital mortality was 9.5% (n=52); of these patients, 30 died after their first MVR and 22 after mitral reoperation. Mortality after isolated MVR was 7.6%. The total follow up was 2,148.9 patient-years, and actuarial survival was 45.0 +/- 15.8% at 15 years. Freedom from structural valve deterioration (SVD) was 51.8 +/- 13.8% for patients aged <50 years, 88.7 +/- 5.1% for those aged 51-60 years, and 84.0 +/- 9.8% for those aged 61-80 years. The incidence of prosthetic valve endocarditis was low, with 88.8 +/- 6.1% non-recurrence in 15 years. Freedom from reoperation was 33.9 +/- 10.4%, and from thromboembolism was 82.3 +/- 15.0%. Freedom from valve-related mortality was 80.7 +/- 12.5% during a 15-year period. CONCLUSION: The 15-year clinical results with the Biocor porcine bioprosthesis in the mitral position were excellent in a young, predominantly rheumatic, patient population which, preoperatively, was in a grave clinical condition. The incidence of valve-related complications was low, as was that of SVD in patients aged >50 years.     

Severe regurgitation immediately after replacement of a dysfunctional bioprosthesis in the mitral valve position

Severe regurgitation immediately after replacement of a cardiac valve with a mechanical prosthesis or a bioprosthesis is a rare occurrence. Such, however, was the case in the patient described.     

A case of 24 years longevity of an Ionescu-Shiley bioprosthesis in the mitral position

Valve dysfunction, attributed to primary tissue failure several years after implantation of Ionescu-Shiley bioprostheses, has led to re-operation in most cases. We report a rare case of this bioprosthesis showing stenosis and regurgitation after implantation in the mitral position 24 years previously. No cusp tears, but severe calcification and well-grown neointima over the Dacron cloth of the inner surface were observed. This may explain how the valve functioned for such a long period of time. We replaced it with a Carpentier-Edwards pericardial bioprosthesis.     

Malfunctioning of the Meadox bioprosthesis placed in mitral position. Description of 2 clinical cases

The Meadox valve, made up by a single bovine pericardial leaflet fixed in glutaraldehyde, is a "new-generation" bio-prostheses. In two patients those bio-prostheses revealed early malfunction with abnormal stretching of the valvular tissue. In both cases the beginning symptom was a strong fremitus caused by the vibration, during systole, of valvular leaflet. In the first case mechanical solicitation onsed partial laceration of valvular leaflet with subsequent regurgitation into the left atrium and cardiac failure. In both cases, the evaluation by Doppler Echocardiography and polygraphic examination, allowed the diagnose of malfunction which was confirmed at surgery. The replacement of a new prosthesis was successful in both cases.     

Carpentier-Edwards bioprosthesis: a 7-year follow-up in 361 patients

Three hundred sixty-one patients undergoing heart valve replacement with Carpentier-Edwards bioprostheses (CE) were evaluated: 169 patients underwent replacement of the mitral valve (MVR), 124 of the aortic valve (AVR), one of the tricuspid valve (TVR) and 67 of 2 or more valves (mVR). A total of 420 CEs were implanted. Overall operative mortality was 4.7% (7.1 for MVR, 1.6 for AVR, 4.5 for mVR). Early complications included hemorrhage (5 cases), thromboembolism (one case), paraprosthetic leak (one case). Actuarial survival rates at 5 years were computed for overall deaths, cardiac deaths and prosthetic deaths. In the 3 subgroups these 3 rates were respectively 78.7 +/- 5.6%, 82.9 +/- 5.4%, 96.4 +/- 1.6% for MVR, 88.9 +/- 3.3%, 94.2 +/- 2.3%, 98.7 +/- 1.3% for AVR, and 82.3 +/- 5.9%, 88.3 +/- 5.1%, 98.5 +/- 1.5% for mVR. Actuarial freedom from prosthetic complications at 7 years was 59.6 +/- 7.5%, 78.1 +/- 4.1% and 61.9 +/- 8.0% for MVR, AVR and mVR patients. Thromboembolism-free rates were 87.2 +/- 3.9% and 99.2 +/- 0.8% for MVR and AVR, while the thromboembolic linearized rate was 2.8% per patient-year and instantaneous risk of thromboembolism was 4.1% at one and instantaneous risk of thromboembolism was 4.1% at one year for MVR. Anticoagulant-related hemorrhage linearized occurrence was 1.0%, 1.2% and 0.8% per patient-year among the 3 subgroups. Prosthetic endocarditis occurred in 12 patients with a linearized rate of 1.1% per patient-year. Eleven of these patients were treated successfully. Three episodes of primary tissue failure were recorded (0.2% linearized rate per year, instantaneous risk 3.5% at the sixth year).(ABSTRACT TRUNCATED AT 250 WORDS)