Ann Thorac Surg 2001;71:S289-S292
© 2001 The Society of Thoracic Surgeons
Bioprosthetic valves and conduits: new developments
Pericarbon pericardial bioprosthesis: an experience based on the lessons of the past
Thierry A. Folliguet, MDa,
Emmanuel Le Bret, MDa,
Jean Bachet, MDa,
François Laborde, MDa
a L’Institut Mutualiste Montsouris, Paris, France
Address reprint requests to Dr Folliguet, L’Institut Mutualiste Montsouris, 46 Boulevard Jourdan, 75014 Paris, France
e-mail: thierry.folliguet{at}imm.fr
Presented at the VIII International Symposium on Cardiac Bioprostheses, Cancun, Mexico, Nov 3–5, 2000.
 |
Abstract
|
|---|
Background. The Pericarbon pericardial bioprosthesis, at the time of its creation, showed a breakthrough in terms of low calcification deposit rate, absence of valvular tears, and durability. The purpose of this study was to evaluate results after 10 years.
Methods. From September 1988 to December 1997, 277 patients received a total of 287 Pericarbon pericardial valves. There were 224 (80.8%) isolated aortic valve replacements (AVR), 39 isolated mitral valve replacements (MVR), 1 tricuspid valve replacement, 3 pulmonary valve replacements, and 10 aortic and mitral valve replacements. The total cumulative follow-up was 1,221.42 patient-years (mean 4.9 ± 2.6 years).
Results. Overall hospital mortality was 10.1%. The overall patient survival at 10.8 years was 55.8% ± 4.2%, for AVR it was 60.0% ± 4.5%, and for MVR it was 46.5% ± 11.9%. The freedom from valve-related death for the overall population at 10.8 years was 98.0% ± 1.0%, for AVR 97.6% ± 1.1%, and for MVR 100%. The overall freedom from structural valve deterioration was 96.6% ± 2.4%, for AVR 96.1% ± 2.7%, and for MVR 100%. The overall freedom from embolic events was 96.0% ± 1.5%, for AVR 96.0% ± 1.6%, and for MVR 100%. The overall freedom from reoperation was 88.1% ± 3.8%, for AVR 89.9% ± 4.2%, and for MVR 80.6% ± 7.3%.
Conclusions. These results show that over a period of up to 10 years, the Pericarbon pericardial bioprosthesis is an excellent and safe valve substitute. Developing a detoxification process aimed at improving the biological behavior of the glutaraldehyde-tanned valve may increase those advantages.
|
Introduction
|
|---|
The porcine bioprosthesis has shown acceptable long-term results in elderly patients in long-term studies [1, 2]. The main advantages of pericardial valves are their alleged improved hemodynamic performance compared with porcine bioprostheses [3, 4]. The first generation of pericardial valves was withdrawn from the market because of a high rate of premature failure. However, the second generation of pericardial valves showed improved results [5, 6]. The purpose of this study was to test long-term efficacy of the Pericarbon bioprosthesis (Sorin Biomedica, Saluggia, Italy) in a large series of patients.
|
Material and methods
|
|---|
The population consisted of 277 patients who underwent valve replacement with a Pericarbon bioprosthesis between September 1988 and December 1997. No other bioprostheses were implanted during the study period. There were 129 men (46.6%) and 148 women (53.4%). Patients were classified symptomatically according to the New York Heart Association (NYHA) classification. Preoperatively 14.4% were in functional class II, 49.5% were in class III, and 32.1% were in class IV. The procedure represented a second valve operation in 36 patients (13.0%). The operation was performed electively in 91.3% and as an emergency procedure in 8.7% patients. Emergency operations included patients on respiratory assistance who were transferred from other institutions or those who had decompensation in the cardiac catheterization laboratory requiring interventions such as defibrillation, external cardiac massage, balloon counterpulsation, or inotropic support. "In-hospital mortality" was defined as death occurring within 30 days of operation or before discharge of the patient from the hospital after the intervention.
Operative data
There were 224 (80.8%) single aortic valve replacements (AVR), 39 single mitral valve replacements (MVR), 1 tricuspid valve replacement (TVR), 3 pulmonary valve replacements (PVR), and 10 aortic and mitral (double) valve replacements (DVR). In total, 287 Pericarbon bioprostheses were implanted. Among the overall population 86 patients (31.0%) were underwent combined procedures, mainly coronary artery bypass graft (71 patients, 82.5%).
All operations were performed with cardiopulmonary bypass and moderate hypothermia. Cardiac arrest was performed with a single dose of crystalloid antegrade cardioplegia, and supplemented with cold pericardial continuous irrigation. All bioprostheses were implanted with interrupted "U" stitches. When coronary bypass grafts were performed, distal anastomoses were done before valve replacement, followed by proximal anastomoses being done under single aortic cross-clamp.
The most frequently implanted aortic sizes were 21 and 23 mm, whereas in the mitral position they were 29 and 31 mm (Table 1).
All patients received heparin in the hospital and underwent anticoagulation for the first 3 months postoperatively. After 3 months, the decision about further anticoagulation was left to the referring physician.
Data sources
Perioperative data were obtained by retrospective review of the patients’ hospital records and catheterization reports. Follow-up information was collected through direct patient contact or from each patient’s personal physician. For all the patients, information from the last echocardiographic examination was collected from the patient’s cardiologist. Follow-up was obtained from 227 patients (91.2%).
Statistical analysis
In the subsequent analysis, morbidity and mortality were reported and classified according to the guidelines expressed by the American Association for Thoracic Surgery and The Society of Thoracic Surgeons Ad Hoc Liaisons Committee. Follow-up data were analyzed and expressed in terms of actuarial event-free and linearized complication rates (%/patient-years). Estimated rates of freedom from events were calculated according to the method of Kaplan and Meier. The values of continuous variables are expressed as the mean ± the standard deviation. The data collected were subjected to both quantitative and qualitative analysis with the aid of the PATS software package (Dendrite Clinical Systems, Portland, OR).
|
Results
|
|---|
Early mortality
The overall hospital mortality was 10.1% (28 patients). The mean Parsonnet score of the deceased patients was 35. Two patients older than 80 years and with ejection fractions less than 30% died in the operating room (0.7%); both underwent DVR. The mortality in patients undergoing isolated AVR was 6.6% (10 patients), that in the patients undergoing isolated MVR was 16.1% (5 patients), that for DVR was 44.4% (4 patients), and that in the patients undergoing combined procedures was 10.8% (9 patients). Of the original population, 249 patients were discharged from the hospital.
Late mortality and morbidity
The average duration of follow-up was 58.8 months. The cumulative follow-up for the series was 1,221.4 patient-years, including 1,032.47 patient-years for the aortic valves and 146.21 years for the mitral valves.
Fifty patients (20.1%) died late, only 4 from valve-related causes (1.6%). Detailed information concerning the causes of late and early death are presented in Table 2.
The patient survival at 10.8 years, including early deaths, was 60.0% ± 4.5% for AVR patients and 46.5% ± 11.9% for MVR (Fig 1). The freedom from late valve-related death for the overall population was 98.0% ± 1.0%, for AVR ± 97.6% 1.1%, and for MVR 100%.
Functional improvement in this patient group has been excellent, with a significant number of the current survivors experiencing an enhanced quality of life. The distribution of the current survivors according to their preoperative and postoperative functional class is shown in Figure 2. Preoperatively, 82.9% of the current survivors were in NYHA functional class III or IV. At the completion of the present follow-up, 90.9% of the patients were in class I or II. No valve thrombosis was observed.
Six AVR patients and 1 DVR patient had late embolic events. The actuarial overall freedom from embolic events was 96.0% ± 1.63% for AVR and 100% for MVR patients (Fig 3).
Four patients experienced bleeding. Two were early events (1 gastric ulcer, 1 tamponade). The other two were late complications, and both patients are alive. The actuarial freedom from anticoagulant-related bleeding for the overall population was 98.3% ± 0.8%, for AVR 98.5% ± 8%, and for MVR 96.6% ± 3.4%.
Ten cases of endocarditis were observed (7 AVR, 3 MVR), three being recurrent episodes (2 MVR, 1 AVR). The actuarial freedom from endocarditis for AVR patients was 96.3% ± 1.4%, and for MVR patients was 91.7% ± 4.6% (Fig 4).
Structural valve deterioration occurred in 3 patients with AVR who underwent redo operations for leaflet calcification. Two of them had the adverse event more than 7 years after implantation (aged 76 and 75 years), the third at 2 years after operation (aged 74 years), having coronary artery disease as an associated risk factor. The percentage of valves free of structural deterioration, plotted by the actuarial method, was 96.6% ± 2.4% for the overall patient population, 96.1% ± 2.7% for the aortic valve, and 100% for the mitral valve. For patients older than 75 years (n = 178, 64.3% of the entire population), the freedom from primary tissue failure was 98.9% ± 2.8%. In addition to these patients, there were two other cases diagnosed as having the beginning of leaflet thickening by echocardiographic examination 3 and 6 years after their operations, respectively. Actuarial freedom from structural valve deterioration, including these last two cases, was 94.8% ± 2.7% for the overall population and 93.9% ± 3.1% for AVR patients. No cases of leaflet tear were reported in this series.
Sixteen patients (9 AVR, 6 MVR, 1 DVR) underwent reoperation (5.7% of the overall population). Freedom from reoperation was 88.1% ± 3.8% for the overall population, 89.9% ± 4.2% for AVR patients, and 80.6% ± 7.3% for MVR patients (Fig 5). Three patients underwent reoperation for structural valve deterioration, 6 for prosthetic valve endocarditis, and 7 for paraprosthetic leakage. Among these patients, 7 received a Pericarbon valve again, whereas the other 8 patients received a different prosthesis and 1 reattachment of the bioprosthesis. All patients survived the redo operation, although a MVR patient died later in the hospital after replacement with a different prosthesis.
The 3 PVR patients were operated for congenital malformation (tetralogy of Fallot) of their native pulmonary valve. Despite their young age (8, 36, 38 years), the patients are all alive and in good clinical condition (2 in NYHA class I, 1 in NYHA class II) after a follow-up period of 6.2, 3.8, and 3.5 years, respectively.
One patient with TVR is alive and in NYHA class I after 4.5 years.
|
Comment
|
|---|
Introduction of pericardial bioprostheses into clinical use was mainly due to evidence of high levels of valvular obstruction with porcine bioprostheses. Despite the promising early hemodynamic results obtained with pericardial prostheses, these valves had been progressively abandoned because of their poor long-term resistance. The first generation of pericardial bioprosthesis had a high rate of structural deterioration, leading to the discontinuance of its use [7]. Based on an analysis of the causes of failures, modifications were made in the design and manufacturing methods. Pathologic experience with the Pericarbon valve showed calcification to be the main cause of late structural failure, causing mainly cusp stiffness and bioprosthesis stenosis [8]. Therefore, a second generation of pericardial valves was made available and current results with pericardial valves have greatly improved, inciting new interest in their clinical use. Today, pericardium is recognized as a valid substitution material for bioprostheses.
The Pericarbon valve represents the new generation of pericardial bioprostheses. Its design was intended to prevent stress concentration at the commissures and tissue abrasion due to leaflet-to-fabric contact, both responsible for early failures in first-generation pericardial valves [9]. Tissue processing was aimed at avoiding collagen disruption, which may affect the tissue resistance to fatigue.
Structural deterioration appears to be a rare event in our series, because 96.1% of the aortic valves and 100% of the mitral valves were free from structural deterioration at 10 years. Freedom from structural deterioration was 98.9% for patients older than 75 years. All structural valve deterioration was a result of calcification, with no leaflet tear encountered on any of the removed valves. To continue to improve those advantages, the goal is to introduce a detoxification process aimed at improving the biological behavior of the glutaraldehyde-tanned valve.
Our overall mortality was high at 10.1%, but this rate is a reflection of the poor condition of some of the patients we operated on, as we had a very high Parsonnet score for the deceased. The results in our series support the use of the second-generation pericardial bioprosthesis as the valve of choice in elderly patients. Most patients have had functional improvement, are free of the need for anticoagulation therapy, and are experiencing an enhanced quality of life. We conclude that the Sorin pericardial valve has a low incidence of valve-related complications, that structural deterioration is infrequent and results from leaflet calcification, and that the low incidence of structural deterioration in patients 75 years or older makes this valve an increasingly appropriate option for this age group.
|
Acknowledgments
|
|---|
We express our gratitude to Xavier Laborde at the Institut Mutualiste Montsouris, for his assistance in data collection.
|
References
|
|---|
-
Glower D.D., Landolfo K.P., Cheruvu S., et al. Determinants of 15-year outcome with 1,119 standard Carpentier-Edwards porcine valves. Ann Thorac Surg 1998;66:S44-S48.
-
Jamieson W.R.E., Burr L.H., Janusz M.T., et al. Carpentier-Edwards standard, and supraannular porcine bioprostheses: comparison of technology. Ann Thorac Surg 1999;67:10-17.[Abstract/Free Full Text]
-
Reichenspurner H., Weinhold C., Nollert G., et al. Comparison of porcine biological valves with pericardial valves—a 12 year clinical experience with 1123 bioprostheses. Thorac Cardiovasc Surg 1995;43:19-26.[Medline]
-
Garcia-Bengoechea J.B., Gonzalez-Juanatey J.R., Rubio J., Duran D., Sierra J. Thromboembolism in patients with pericardial valves in the absence of chronic anticoagulation: 12 years’ experience. Eur J Cardiothorac Surg 1991;5:592-597.[Abstract]
-
Banbury M.K., Cosgrove D.M., III, Lytle B.W., Smedira N.G., Sabik J.F., Saunders C.R. Long-term results of the Carpentier-Edwards pericardial aortic valve: a 12-year follow-up. Ann Thorac Surg 1998;66:S73-S76.
-
Marchand M., Aupart M., Norton R., et al. Twelve-year experience with Carpentier-Edwards Perimount pericardial valve in the mitral position. a multicenter study. J Heart Valve Dis 1998;7:292-298.[Medline]
-
Pelletier L.C., Carrier M., Leclerc Y., Lepage G., deGuise P., Dyrda I. Porcine versus pericardial bioprostheses: a comparison of late results in 1,593 patients. Ann Thorac Surg 1989;47:352-361.[Abstract]
-
Valente M., Ius P., Bortolotti U., Talenti E., Bottio T., Thiene G. Pathology of the pericarbon bovine pericardial xenograft implanted in humans. J Heart Valve Dis 1998;7:180-189.[Medline]
-
Thiene G., Laborde F., Valente M., Gallix P. Morphological survey of a new pericardial valve prosthesis (Pericarbon): long-term animal experimental model. Eur J Cardiothorac Surg 1989;3:65-74.[Abstract]
This article has been cited by other articles:
|
|
|
|
 
F. Botzenhardt, W. B. Eichinger, S. Bleiziffer, R. Guenzinger, I. M. Wagner, R. Bauernschmitt, and R. Lange
Hemodynamic Comparison of Bioprostheses for Complete Supra-Annular Position in Patients With Small Aortic Annulus
J. Am. Coll. Cardiol.,
June 21, 2005;
45(12):
2054 - 2060.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
