An assessment of the mechanical properties of leaflets from four second-generation porcine bioprostheses with biaxial testing techniques

The aim of this study was to determine whether second-generation porcine bioprostheses, glutaraldehyde fixed at pressures said to be less than 4 mm Hg, exhibit more natural leaflet material properties than earlier valves fixed at 80 to 100 mm Hg. Biaxial mechanical testing techniques were used to compare Carpentier-Edwards SAV, St. Jude Medical BioImplant, Hancock II, and Medtronic Intact bioprostheses (12 leaflets from four valves in each case) with fresh porcine aortic valves and high pressure-fixed Carpentier-Edwards 6625 bioprostheses (14 leaflets from five valves in each case). The circumferential extensibility of leaflets from Medtronic Intact bioprostheses and from fresh porcine aortic valves were not significantly different (p greater than 0.05), whereas leaflets from the other second-generation valves tested and from Carpentier-Edwards 6625 valves were highly inextensible in the circumferential direction. The radial material properties of leaflets from all bioprostheses differed from those of fresh porcine aortic valves, which were very extensible with a high pretransitional compliance. The radial extensibility and compliance of Hancock II, St. Jude Medical BioImplant, and Carpentier-Edwards 6625 leaflets were not significantly different (p greater than 0.05). In the radial direction, Carpentier-Edwards SAV and Medtronic Intact valve leaflets were substantially more extensible than Carpentier-Edwards 6625 leaflets (p less than 0.01), whereas Medtronic Intact leaflets were more compliant than all other bioprostheses. These data demonstrate (1) that second-generation porcine bioprosthetic valves do not necessarily exhibit more natural leaflet material properties than earlier high pressure-fixed xenografts and (2) that Medtronic Intact valve leaflets have material properties most closely approximating the fresh porcine aortic valve.     

In vitro hemodynamic characteristics of tissue bioprostheses in the aortic position

The in vitro hemodynamic characteristics of a variety of old and new generation porcine and bovine pericardial bioprostheses were investigated in the aortic position under pulsatile flow conditions. The following valves were studied: Carpentier-Edwards porcine (Models 2625 and 2650), Carpentier-Edwards pericardial, Hancock porcine (Models 242, 250, and 410), Hancock pericardial, and Ionescu-Shiley (standard and low-profile) bioprostheses. The pressure drop results indicated that the old design valves had performance indices in the range of 0.30 to 0.42, whereas the new low-pressure fixed designs have performance indices of 0.50 to 0.70. Flow visualization and velocity and turbulent shear stress measurements, conducted with a two-dimensional laser Doppler anemometer system, indicated that all tissue valve designs created jet-type flow fields. The intensity of the jets and turbulence levels were less severe with the new designs. The old designs created higher peak jet velocities and higher levels of turbulent shear stresses. On the whole, pericardial bioprostheses have better in vitro hemodynamic characteristics than porcine bioprostheses. These observations should have applications regarding the clinical choice of bioprosthetic valves and have implications regarding further improvements in the preparation and design of bioprosthetic valves.     

Clinical assessment of prosthetic valve replacement of the right-sided cardiac valves: mechanical or bioprosthesis?

Clinical results with mechanical and bioprosthetic valve replacements for tricuspid and/or pulmonary positions were reviewed. Between February 1975 and December 1985, 34 bioprostheses (B) (22 Hancock, 9 Ionescu-Shiley and 3 Carpentier-Edwards pericardial) and 18 mechanical prostheses (M) (St. Jude Medical) were implanted in our institute excluding hospital death. Group with B included 29 tricuspid valve replacements and 5 pulmonary valve replacements. Group with M included 9 tricuspid valve replacements, 7 pulmonary valve replacements and 1 both valve replacements. The cumulative follow-up period was 207.2 patient-years (p-t) in group B and 55.0 p-y in group M. The incidence of valve failure was 0.48 +/- 0.48% per p-y in group B and 7.27 +/- 3.64% per p-y in group M (p less than 0.001). The incidence of valve-related events was 1.93 +/- 0.97% per p-y in group B and 9.09 +/- 4.07% per p-y in group M (p less than 0.001). At 3 years, the percent free of valve failure was 100 +/- 0% in group B and 76.8 +/- 10.2% in group M (p less than 0.05). Fourteen bioprosthetic valves (B') and 10 mechanical valves (M') were implanted at the right-sided cardiac valve position alone. The cumulative follow-up period was 94.2 p-y in group B' and 32.3 p-y in group M'. The incidence of valve-related events was 1.06 +/- 1.06% per p-y in group B' and 12.4 +/- 6.19% per p-y in group M' (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Primary tissue valve degeneration in glutaraldehyde-preserved porcine bioprostheses: Hancock I versus Carpentier-Edwards at 4- to 7-years' follow-up

In the 32-month period between April, 1978, and December, 1980, 292 patients, divided into two equal groups, received a glutaraldehyde porcine bioprosthesis--either Hancock or Carpentier-Edwards (CE)--as mitral valve substitute. Every patient receiving a mitral porcine xenograft during that time was included in the study. The type of bioprosthesis was always selected by the surgeon and not randomly. Preoperative clinical characteristics, associated surgical procedures, valve implantation sizes, and follow-up data showed no relevant differences between the two groups. There were three instances of primary tissue failure in the Hancock group and six in the CE (linearized rates of 0.49 and 0.97 events percentage of patient/years, respectively). Mean duration of explanted valves and microscopic findings were similar in both groups. Primary tissue failure was more frequent in patients under 40 years of age in both groups, although differences were not statistically significant. A marginally significant trend toward greater incidence of tissue failure in patients of 40 years of age and older was seen in the CE group when compared with the Hancock group. Actuarial survival of the bioprostheses free from primary tissue failure was 6.5 years of 95 +/- 3% (mean +/- standard error) for Hancock and 84 +/- 9% for CE (p = NS). No significant difference in terms of durability has been found between the two most popular glutaraldehyde porcine bioprostheses, although the behavior of the CE in patients older than 40 years should be reassessed in a study with a larger number of patients and a longer follow-up period.     

Ten-year echocardiographic and clinical follow-up of aortic Carpentier-Edwards pericardial and supraannular prosthesis: a case-match study

BACKGROUND: There are little comparative data on Carpentier-Edwards supraannular and pericardial second-generation bioprostheses. The aim of this work was to compare their hemodynamic and clinical outcomes in patients with aortic stenosis. METHODS: We conducted a retrospective study including 150 patients operated on for aortic stenosis between 1989 and 1993. Patients undergoing aortic valve replacement with either a Carpentier-Edwards supraannular or pericardial prosthesis were matched for sex (49% male), age (72 +/- 8 years), body surface area, valve size, associated procedures, and left ventricular ejection fraction. RESULTS: Mean follow-up was 6.5 +/- 3.3 years, giving a total follow-up of 983 patient-years. Thirty-day mortality and 10-year actuarial survival were, respectively, 8% and 51% in the supraannular group and 6.7% and 43.4% in the pericardial group. At 10 years, freedom from thromboembolism, structural failure, and all valve-related events were, respectively, 88.7%, 88.9%, and 68.7% in the supraannular group and 85%, 100%, and 82.2% in the pericardial group. There were four (5.3%) structural failures, and four (5.3%) reoperations for degeneration (n = 3) and endocarditis (n = 1) in the supraannular group. Freedom from structural dysfunction or reoperation was 87.3% in the supraannular group and 100% (p < 0.05) in the pericardial group. Echocardiographic review of 62 of 76 survivors (81.5%) demonstrated a trend toward a better hemodynamic profile of pericardial valves at the end of follow-up. CONCLUSIONS: Ten years after aortic valve replacement for aortic stenosis, Carpentier-Edwards pericardial prostheses give comparable and probably better results than Carpentier-Edwards supraannular prostheses.     

Comparison of long-term results of Carpentier-Edwards and Hancock bioprosthetic valves

The long-term survival following valve replacement with Carpentier-Edwards or Hancock bioprostheses was compared between the two valve models and between the two groups totaling 407 patients who were discharged after valve replacement beginning in 1974. The two groups of patients were treated in a nonrandomized fashion. The actuarial survival for 299 patients with Carpentier-Edwards valves was 94 +/- 1.5% (+/- standard error) and 93 +/- 1.7% after 5 and 8 years of follow-up, respectively. Comparable figures for 108 patients undergoing valve replacement with Hancock valves were 89 +/- 3.0% and 83 +/- 3.7%, respectively (p = not significant [NS]). The probability of freedom from death and valve removal after 5 and 8 years of follow-up was 91 +/- 1.8% and 79 +/- 4.6%, respectively, with the Carpentier-Edwards valve and 84 +/- 3.5% and 75 +/- 4.3%, respectively, with the Hancock valve (p = NS). An accelerated rate of attrition for both valves was observed in the mitral position. There were no significant differences in actuarial survival between the two valves in the mitral or the aortic position or in the incidence of major valve-related complications.     

Dynamic behavior of prosthetic aortic tissue valves as viewed by high-speed cinematography.

Using a valve testing apparatus of our own design and with a high-speed (600 to 800 frames per second) 16 mm movie camera, films were made of Hancock porcine, Carpentier-Edwards porcine, and Ionescu-Shiley bovine pericardial valves mounted in the aortic position and cycled under physiological conditions at 72 to 100 beats per minute. Fresh and explanted valves were observed using saline or 36.5% glycerol as the pumping solution. When fresh valves were studied using saline solution as the pumpint fluid, the Hancock and Carpentier-Edwards porcine valves showed high-frequency leaflet vibration, which increased in frequency with higher cycling rates. Abnormal leaflet motion was decreased when glycerol was used as the blood analogue. The Ionescu-Shiley bovine pericardial valve did not show abnormal leaflet motion under these conditions. Conclusions drawn from tissue valve testing studies that use excessively high pulsing rates and pressures (accelerated testing) and saline or water as pumping solutions cannot be transposed to predict the fate of tissue valves in a clinical setting.     

Hydrodynamic Function of Second Generation Porcine Bioprosthetic Heart Valves

The hydrodynamic function and leaflet dynamics of second generation porcine valves prepared with low- or zero-pressure fixation have been studied and compared to first generation porcine bioprostheses, bileaflet, and tilting disc mechanical valves. The Carpentier-Edwards Supra-Annular and Hancock II valves showed lower pressure drops than the Medtronic Intact valve and first generation porcine valves, and comparable overall energy losses to mechanical valves at normal cardiac outputs. Only the zero-pressure fixed Intact valve showed synchronous leaflet opening. Delayed leaflet opening and high opening pressures were found in both low- and high-pressure fixed porcine valves. All porcine bioprostheses showed high open leaflet bending strains. Fixation of valve leaflets with "near zero" pressure fixation and a more physiological neutral geometry is necessary to ensure synchronous leaflet opening at low flows and a reduction in commissural bending strains.     

An eight-year experience with porcine bioprosthetic cardiac valves

A total of 589 porcine bioprostheses were implanted in 509 patients from January, 1976, through December, 1983. Of the valves implanted, 390 were Hancock and 199 were Carpentier-Edwards. A total of 1,633 patient-years was accrued, with a mean follow-up of 38 months per patient. Two hundred eight patients had aortic valve replacement, 209 had mitral valve replacement, and 79 had multiple valve replacements, of which 46 were aortic and mitral replacements. The mortality for isolated aortic valve replacement was 5.8%; for isolated mitral replacement, 8.6%, and for all patients, 10.9%. Late mortality was 3.9% per patient-year. The actuarial survival rate at 5 years was 79% for aortic, 68% for mitral, and 76% for aortic-mitral valve replacement. There were 12 thromboembolic events (0.73% per patient-year). Two episodes occurred in patients with an aortic bioprosthesis, nine in patients with a porcine mitral valve, and one in a patient with mitral and tricuspid bioprosthetic valves. The probability of remaining free of thromboembolism at 5 years was 99% for the group having aortic valve replacement, 93% for those having mitral replacement, and 100% for the group having aortic-mitral valve replacements. Thirteen episodes of endocarditis occurred (0.8% per patient-year). Seven of the 13 patients died as a direct result of endocarditis. The probability of remaining free of prosthetic endocarditis at 5 years was 97% for the aortic valve replacement group, 95% for the mitral group, and 97% for the aortic-mitral group. There were 20 instances of xenograft failure (1.2% per patient-year). The probability of remaining free of valve failure at 5 years was 96% for the aortic valve replacement group, 93% for the mitral group, and 93% for the aortic-mitral replacement group. Primary tissue failure of a prosthesis occurred in seven patients, all with Hancock valves (0.43% per patient-year). As yet there has been no primary tissue failure of the Carpentier-Edwards prosthesis. There also appears to be a lower incidence of thromboembolism (Edwards, 0.3% per patient-year; Hancock, 0.8% per patient-year) and endocarditis (Edwards, 0.6% per patient-year; Hancock, 1.0% per patient-year). The low incidence of complications with the porcine bioprosthetic valve, especially the Carpentier-Edwards, encourages us to recommend its continued use, especially in situations in which anticoagulation is contraindicated.     

Carpentier-Edwards pericardial aortic valve in middle-aged patients comparison with the St. Jude medical valve

Objective The objective of the present study was to compare long-term results of single aortic valve replacement (AVR) with mechanical (St. Jude Medical valves: standard) and biologic (the Carpentier-Edwards pericardial) prostheses. Method: Between 1995 and 2002, 95 patients who underwent single AVR with mechanical (n=46) or biologic (n=49) prostheses were enrolled in this study. The mean age at the operation was 54.0±9.6 years (range: 20 to 69 years) with the mechanical and 68.8±7.1 years (range: 44 to 85 years) with the biologic prosthesis. Results: The 9-year actuarial survival rate, which was calculated by taking perioperative mortality into account, was 90.3±4.6% for patients with mechanical valves and 87.6 ±4.8% for patients with bioprostheses, with no difference between the two groups (p=0.342). The 9-year freedom rate from thromboembolism, reoperation, endocarditis was 94.8+3.6%, 100% and 97.8 ±2.2% for patients with mechanical valves and 98.0 ±2.0%, 97.5 ±3.4% and 95.0 ±3.4% for those with bioprostheses, respectively. After 9 years, freedom from cardiac death averaged 97.8% in the group with mechanical valves compared with 95.3% in those with bioprostheses (p=0.541). Conclusion: We conclude that the mid-term durability of the Carpentier-Edwards pericardial valve in the aortic position for the elderly is excellent. Nevertheless, the risk of tissue valve reoperation progressively increases with time, and a longer follow-up may be necessary to provide its value compared with the mechanical valves in a country like Japan with a high life expectancy. (Jpn J Thorac Cardiovasc Surg 2005; 53:465-469)     

Stentless porcine and pericardial valve in aortic position.

Fifty-seven patients underwent aortic valve replacement with a stentless glutaraldehyde-fixed bioprosthesis; 27 received a porcine aortic valve and 30 had a bovine pericardial valve. Two groups of 30 patients each who had aortic valve replacement with a tilting-disc mechanical valve or a stented porcine bioprosthesis served as controls. There were no differences in sex, body surface area, valve lesion, and valve size among the four groups. Results were assessed on a Doppler-based determination of maximum velocity across the valve, aortic valve area, and degree of valve regurgitation. Velocity across the valve was significantly less with stentless pericardial valves than with stentless porcine valves, stented bioprostheses, and mechanical valves. Stentless valves had a significantly larger aortic valve area when compared with stented valves. Mild central aortic insufficiency was detected more often with stentless pericardial than with stentless porcine bioprostheses (p = 0.04). Stentless valves showed a higher incidence of complete atrioventricular block when compared with stented valves (p = 0.04). Long-term studies are now warranted to assess the durability of both types of stentless valves.     

Rest and exercise hemodynamics following aortic valve replacement. A comparison between 19 and 21 mm Ionescu-Shiley pericardial and Carpentier-Edwards porcine valves

When aortic valve replacement is performed in a patient with a small anulus, significant obstruction of the left ventricular outflow tract may remain. Most prostheses are obstructive in the smaller sizes, and enlargement of the aortic anulus may be required to allow placement of a larger valve. To evaluate the hemodynamic performance of two commonly used tissue prostheses, the Ionescu-Shiley pericardial and Carpentier-Edwards porcine valves, 22 patients with either the 19 or 21 mm size were electively studied at rest and after exercise at a mean of 15 months after operation. The resting mean transvalvular gradient for 19 mm Ionescu-Shiley pericardial valves (n = 7), 10.6 +/- 9.2 mm Hg, was significantly lower than that for 19 mm Carpentier-Edwards valves (n = 3), 33.3 +/- 2.1 mm Hg, p less than 0.01. Following exercise, the mean gradient for 19 mm Ionescu-Shiley pericardial valves rose only to 13.8 +/- 8.5 mm Hg. No exercise data were available for the 19 mm Carpentier-Edwards valve. Among patients with 21 mm Ionescu-Shiley pericardial valves (n = 7), the mean transvalvular gradient at rest was 5.6 +/- 9.5 mm Hg, not significantly different from that of patients with 21 mm Carpentier-Edwards valves (n = 5), 9.8 +/- 18.3 mm Hg. After exercise, the gradients rose to 16.0 +/- 10.0 mm Hg and 25.5 +/- 23.8 mm Hg for the Ionescu-Shiley pericardial and Carpentier-Edwards valves, respectively (no statistical significance). Cardiac index was not different between groups. Gradients were not significantly higher in patients with body surface areas greater than 1.5 m2. It is concluded that the 19 and 21 mm Ionescu-Shiley pericardial valves possess excellent hemodynamics, even after exercise. This valve appears hemodynamically superior to the Carpentier-Edwards valve, particularly in the 19 mm size. Procedures to enlarge the aortic anulus are usually unnecessary when small Ionescu-Shiley pericardial valves are used, even in patients who have large body surface areas.     

Long-term results of porcine bioprosthetic valves

Between November 1977 and October 1980, 54 patients underwent valve replacements with porcine bioprostheses at Hyogo Kenritsu Amagasaki Hospital. The late complications and the long term durability of 53 porcine bioprostheses were documented in 48 patients after discharge (34 mitral, 7 aortic, 2 tricuspid, and 5 multiple, consisting of 38 Hancock, 15 Carpentier-Edwards prostheses). Cumulative duration of follow-up is 420 patient-years. The valve related late mortality was 0.52%/patient-years. There were 6 thromboembolic events (1.6% patient-years), only 1 episode of endocarditis (0.26%/patient-years). Valve dysfunction is defined as stenosis or regurgitation by echocardiogram or cardiac catheterization. There were 21 instances of porcine bioprosthetic dysfunction (6.6% patient-years). Freedom from valve dysfunction at 12 years was 24.4%. There were 17 valves of mitral bioprosthetic dysfunction (6.4% patient-years). The incidences of mitral stenosis (MS), mitral regurgitation (MR), and paravalvular leakage were 4.5, 3.6, and 0.7%/patient-years respectively. Freedom from MR was higher than MS at 8 years. The 14 patients were needed reoperation due to valve dysfunction (3.6%/patient-years). We concluded that the porcine bioprostheses showed a high incidence of valve dysfunction at 7 to 8 years after operation, we presently choose mechanical valve in most cases.     

In vivo hemodynamic comparison of porcine and pericardial valves

The bovine pericardial valve and the SupraAnnular valve have been developed to improve the hemodynamic function of tissue valves. Hemodynamic performances of the standard Carpentier-Edwards porcine valve, the Carpentier-Edwards SupraAnnular valve, and the Carpentier-Edwards bovine pericardial valve were compared in the aortic position. One hundred patients undergoing aortic valve replacement were studied intraoperatively. Mean gradient across the valve decreased for standard and pericardial valves as valve size increased. At the same flow rate, the 23 mm pericardial valve had larger valve orifice areas, higher performance indices, and lower gradients than the 23 mm SupraAnnular valve. The SupraAnnular valve is hemodynamically superior to the standard Carpentier-Edwards porcine bioprosthesis. The Carpentier-Edwards pericardial valve, however, is less obstructive in the aortic position than either of the porcine valves.     

Long-term results of bioprosthetic mitral valve replacement: the pericardial perspective

Pericardial valve bioprostheses were introduced in early 1970s and were widely used in the 1980s. The longterm results with the Ionescu-Shiley valve, the first commercially available pericardial valve, were disappointing because of high rate cusp tears during the first decade after implantation. The enthusiasm for this type of bioprosthetic valve was further hampered by the premature failure of the Hancock pericardial valve. The long-term results of aortic valve replacement with the Carpentier-Edwards pericardial valve, which was introduced in 1981, indicated that that valve was durable and the issue of cusp tears had been resolved by an appropriate design. This knowledge prompted surgeons to revisit the merits of pericardial valves for mitral valve replacement and several other pericardial valves are now commercially available. The largest data on long-term results are with the Carpentier-Edwards pericardial mitral valve. The reported freedom from structure valve failure ranged from 69% to 85% at 10 years in patient population with mean age of 60 to 70 years. Young age is a major determinant of valve failure, which is largely due to calcification. There are also long-term data, albeit more limited on the Sorin Pericarbon and Mitroflow valves used for mitral valve replacement. This paper review the published experience with various pericardial bioprosthetic valves used for mitral valve replacement during the past 3 decades.     

Porcine versus pericardial bioprostheses: a comparison of late results in 1,593 patients

From 1976 to 1988, 1,593 patients underwent valve replacement with a porcine (878 patients) or a pericardial bioprosthesis (715 patients). There were 701 aortic, 678 mitral, and 214 multiple-valve replacements. Follow-up was obtained for 1,559 patients (98%). Early mortality was 9% (79 patients) in the porcine valve group and 5% (37 patients) among patients with a pericardial valve (p less than 0.01). Late survival after replacement with porcine valves was 80% +/- 1% and 62% +/- 3% at 5 and 10 years, respectively. With pericardial valves, 5-year survival was 79% +/- 2%. Among valve-related complications, rates of freedom from thromboembolism, endocarditis, and hemorrhage after 6 years were similar for both valve groups. Freedom from reoperation at 6 years was also similar after aortic (96% versus 91%) or multiple-valve replacement (95% versus 88%). However, for mitral valve replacement, freedom from reoperation was significantly better with porcine valves than with pericardial valves at 6 years (92% versus 68%; p less than 0.001). This difference was mainly due to the Ionescu-Shiley valve, which accounted for 83% of primary tissue failures among pericardial bioprostheses implanted in the mitral position (10/12 patients). After 6 years, freedom from primary tissue failure of mitral valves was 92% +/- 2% with porcine and 70% +/- 11% with pericardial bioprostheses (p less than 0.0001). The degree of clinical improvement among survivors was similar with both valve types. Thus, in the aortic position, pericardial valves compare with porcine valves up to 6 years, whereas in the mitral position, the durability of the former is significantly less, mainly because of the suboptimal performance of the Ionescu-Shiley pericardial bioprosthesis.     

Necessity of permanent anticoagulant therapy for isolated mitral valve replacement with bioprosthetic heart valve to prevent the postoperative thromboembolic complications

One hundred fifty four patients underwent isolated mitral valve replacement with bioprosthetic heart valve at Hyogo Medical College Hospital from November 1973 to December 1998. A porcine bioprosthetic valve was replaced in 82 patients (Hancock 43, Carpentier-Edwards 26, Hancock II 13) and pericardial bioprosthetic valve in 72 patients (Ionescue-Shiley 39, Carpentier-Edwards 33) with a mean follow-up of 1,410 patients-years. Their thromboembolism rates were also analyzed in linear and actuarial term over the 15-year period. The incidence of thromboembolism rate was 2.5%/pt.yr. Thromboembolic free rates for patients with anticoagulant therapy were significantly decreased for patients without therapy. Thromboembolic free rates for patients with atrial fibliration were also were significantly decreased for patients with sinus rhythm because the patients with sinus rhythm were not on anticoagulant therapy. In conclusion, it is necessary for the all patients to be on anticoagulant therapy after mitral valve replacement with bioprosthetic valves, even though patients with sinus rhythm.     

Surgical treatment of valvular heart disease.

Surgeons are presently able to choose from a variety of satisfactory valve prostheses, depending on the individual situation. The durability, thromboembolic potential, and hemodynamic properties of any valve must be balanced against specific anatomic and clinical factors. Thus, if a surgeon is most concerned about durability, he might choose the bare strut Starr-Edwards ball valve or the Smeloff-Cutter valve, the most proven valves by length of service. However, the Bjork-Shiley, Lillehei-Kaster, and Hancock valves all have good durability records to seven years.Thromboembolic potential is markedly decreased with tissue valves such as the Hancock porcine xenograft, Carpentier-Edwards porcine xenograft, Ionescu-Shiley pericardial valve, or dura mater valve. Patients with these valves do not usually require chronic anticoagulation, which is associated with significant morbidity and mortality. In clinical situations that contraindicate long-term anticoagulation or when the threat of thromboembolism or bleeding is very high, the use of a tissue valve is particularly indicated.Hemodynamic considerations may be paramount in some patients with restrictive anatomy; the small diameter, tilting disc valves have the best hemodynamic performance, although new modifications in the Hancock porcine heterograft may reduce the hemodynamic obstruction in these small diameter valves and allow their implantation without long-term anticoagulation.A number of durable and effective devices exist today for valve replacement, and the type of valve used can be individualized according to the valve characteristics, clinical indications, and anatomic considerations.     

Comparison of Carpentier-Edwards pericardial and supraannular bioprostheses in aortic valve replacement.

OBJECTIVE: This study aimed at calculating and comparing the long-term outcomes of patients after aortic valve replacement with the Carpentier-Edwards bovine pericardial and porcine supraannular bioprostheses using microsimulation. METHODS: We conducted a meta-analysis of eight studies on the Carpentier-Edwards pericardial valves (2,685 patients, 12,250 patient-years) and five studies on the supraannular valves (3,796 patients, 20,127 patient-years) to estimate the occurrence rates of valve-related events. Eighteen-year follow-up data sets were used to construct age-dependent Weibull curves that described their structural valvular deterioration. The estimates were entered into a microsimulation model, which was used to calculate the outcomes of patients after aortic valve replacement. RESULTS: The annual hazard rates for thrombo-embolism after aortic valve replacement were 1.35% and 1.76% for the pericardial and supraannular valves, respectively. For a 65-year-old male, median time to structural valvular deterioration was 20.1 and 22.2 years while the lifetime risk of reoperation due to structural valvular deterioration was 18.3% and 14.0%, respectively. The life expectancy of the patient was 10.8 and 10.9 years and event-free life expectancy 9.0 and 8.8 years, respectively. CONCLUSIONS: The microsimulation methodology provides insight into the prognosis of a patient after aortic valve replacement with any given valve type. Both the Carpentier-Edwards pericardial and supraannular valve types perform satisfactorily, especially in elderly patients, and show no appreciable difference in long-term outcomes when implanted in the aortic position.     

Survival and valve failure after aortic valve replacement.

A prospective evaluation of 412 consecutive patients undergoing isolated aortic valve replacement between January 1982 and December 1985 was performed in an attempt to identify the determinants of survival and valve failure. A variety of valves were inserted to permit a prospective evaluation of alternative valves including: Bj?rk-Shiley mechanical (n = 37), Ionescu-Shiley pericardial (n = 261), Hancock pericardial (n = 78), and Carpentier-Edwards porcine (n = 36). Thirteen patients died in the hospital (3.2%) and 47 patients died in the follow-up period producing an actuarial survival of 81% +/- 3% at 48 months. Survival was independently predicted by advancing age, preoperative New York Heart Association functional class, and the presence of endocarditis (p less than 0.05 by Cox regression analysis). The majority of patients were symptomatically improved (New York Heart Association class I or II: 21% preoperative, 88% postoperative). Freedom from structural valve dysfunction, prosthetic valve endocarditis, and reoperation for valve-related complications were 95% +/- 2%, 95% +/- 2%, and 92% +/- 2% at 48 months, respectively. These valve-related complications occurred more frequently in younger patients and in those with a Hancock pericardial valve (freedom from structural valve dysfunction, 89% +/- 5%; prosthetic valve endocarditis, 84% +/- 9%; reoperation, 78% +/- 10%; p less than 0.05 by Cox regression). Freedom from thromboembolism was 88% +/- 2% at 48 months; it was significantly lower in patients with a preoperative thromboembolic event and was not influenced by the type of prosthesis inserted. Freedom from anticoagulant-related hemorrhage was 85% +/- 8% at 48 months and was not influenced by any preoperative factors.(ABSTRACT TRUNCATED AT 250 WORDS)