Porcine Prostheses Research Articles

Durability of porcine and pericardial prostheses in tricuspid valve replacement

ObjectiveBiologic valves dominate tricuspid valve replacement, yet data on different valve types are lacking. We compare the survival and durability of porcine and pericardial tricuspid prostheses. MethodsA retrospective review of consecutive patients undergoing tricuspid valve replacement with porcine (N = 542) or pericardial (N = 144) prostheses between 1975 and 2022 was performed using a prospectively maintained institutional database. Concurrent procedures were included. Cox proportional hazards and logistic regression were performed. ResultsPatients who received the porcine prosthesis, compared with pericardial, were younger (56 ± 17 years vs 63 ± 15 years) and more likely to present urgently (55% porcine, 44% pericardial); however, there were no differences in redo status or concomitant operations. Ten-year survival was not significantly different between the porcine and pericardial groups (35% ± 3% vs 28% ± 4%, respectively, P = .2). The 10-year cumulative incidence of structural valve deterioration (porcine 9% ± 2%, pericardial 11% ± 3%, P = .8), reoperation for structural valve deterioration (porcine 5% ± 1%, pericardial 4% ± 2%, P = .06), and severe regurgitation (porcine 4% ± 1%, pericardial 5% ± 2%, P = .7) were not significantly different between groups. The failure mode was similar, with no difference in severe stenosis (porcine 32/47 [68%], pericardial 11/16 [69%], P = .9) or severe regurgitation (porcine 18/47 [38%], pericardial 7/16 [44%], P = .7). On regression analysis, valve type was not associated with survival (P = .6). Valve type was not associated with structural valve deterioration (P = .1) or reoperation for structural valve deterioration (P = .9). ConclusionsIn our series, there were no differences in survival or durability between porcine and pericardial valves. In most patients undergoing tricuspid valve replacement, the choice of porcine versus pericardial prosthesis is unlikely to affect clinical outcomes.

Bovine pericardial versus porcine bioprosthetic aortic valves: A nationwide population-based cohort study in Korea

ObjectiveTo compare the clinical outcomes of aortic valve replacement (AVR) using bovine pericardial and porcine bioprostheses, utilizing a nationwide administrative claims database. MethodsAdult patients (age ≥40 years) who underwent bioprosthetic AVR, without other valve replacements, between 2003 and 2018 were identified from the Korean National Health Insurance Service database. The outcomes of interest were all-cause mortality, cardiac mortality, and valve-related events, including the incidence of reoperation, endocarditis, systemic thromboembolism, and major bleeding. Baseline adjustment was performed using propensity score matching. Time-related outcomes were evaluated using a competing risk analysis, with death as a competing risk. ResultsAmong the 7714 patients who underwent bioprosthetic AVR, 5621 (72.9%) received bovine pericardial prostheses and 2093 (27.1%) received porcine bioprostheses. After matching, 1937 pairs were included in the final analysis. During follow-up (median, 4.49 years; interquartile range, 2.83-8.20 years), the use of porcine bioprostheses was associated with a higher risk of aortic valve reoperation (adjusted hazard ratio [HR], 1.87; 95% confidence interval [CI], 1.16 to 3.01); however, no significant differences were observed in cumulative incidences of all-cause mortality, cardiac mortality, thromboembolism, or major bleeding. Subgroup analyses revealed that the use of bovine valves was associated with improved survival in patients with diabetes mellitus, whereas in patients undergoing dialysis, porcine valves exhibited better survival than bovine valves. ConclusionsIn this large nationwide cohort study of patients undergoing bioprosthetic aortic valve replacement, the use of porcine prostheses was significantly associated with an increased risk of reoperation compared with the use of bovine prostheses, supporting previous findings.

Outcomes of bovine versus porcine surgical aortic valve replacement.

There are no guidelines regarding the use of bovine pericardial or porcine valves for aortic valve replacement, and prior studies have yielded conflicting results. The current study sought to compare short- and long-term outcomes in propensity-matched cohorts of patients undergoing isolated aortic valve replacement(AVR) with bovine versus porcine valves. This was a retrospective study utilizing an institutional database of all isolated bioprosthetic surgical aortic valve replacements performed at our center from 2010 to 2020. Patients were stratified according to type of bioprosthetic valve (bovine pericardial or porcine), and 1:1 propensity-score matching was applied. Kaplan-Meier survival estimation and multivariable Cox regression for mortality were performed. Cumulative incidence functions were generated for all-cause readmissions and aortic valve reinterventions. A total of 1502 patients were identified, 1090 (72.6%) of whom received a bovine prosthesis and 412 (27.4%) of whom received a porcine prosthesis. Propensity-score matching resulted in 412 risk-adjusted pairs. There were no significant differences in clinical or echocardiographic postoperative outcomes in the matched cohorts. Kaplan-Meier survival estimates were comparable, and, on multivariable Cox regression, valve type was not significantly associated with long-term mortality (hazard ratio: 1.02, 95% confidence interval: 0.74, 1.40, p = .924). Additionally, there were no significant differences in competing-risk cumulative incidence estimates for all-cause readmissions (p = .68) or aortic valve reinterventions (p = .25) in the matched cohorts. The use of either bovine or porcine bioprosthetic aortic valves yields comparable postoperative outcomes, long-term survival, freedom from reintervention, and freedom from readmission.

Immobile Leaflets at Time of Bioprosthetic Valve Implantation: A Novel Risk Factor for Early Bioprosthetic Failure: A Novel Risk Factor for Early Bioprosthetic Failure

The clinical implications of finding immobile leaflet(s) at the time of bioprosthetic valve implantation but with acceptable prosthetic haemodynamics are uncertain. We sought to determine the characteristics of such patients and their impact on outcome. Patients with immobile leaflet at the time of surgical bioprosthetic valve implantation were identified retrospectively by a systematic search of an institutional echocardiography database (2010-2020). Intraoperative echocardiograms were reviewed de-novo to confirm immobile leaflet(s) at the time of implantation. Cases were matched 1:2 to controls with normal bioprosthetic leaflets motion for age, sex, prosthesis position, prosthesis model, size, year of implantation, and pre-implantation left ventricular ejection fraction. Proportional hazards method was used to analyse the composite endpoint of stroke, valve thrombosis or re-intervention. Immobile leaflet at the time of bioprosthetic valve implantation were found in 26 patients (median age 71 ys 39% males) following tricuspid (n=13), mitral (n=11) and aortic (n=2) valve replacements; 96% received porcine prostheses; prosthesis size was 27 mm or larger in 92%. Immobile leaflet were recorded on intraoperative reports in 16 (62%) cases. It resulted in elevated gradient or mild-moderate prosthetic regurgitation in three (12%), but none led to immediate corrective action intraoperatively. At median follow-up of 21 (4-50) months, presence of immobile leaflet was associated with composite clinical endpoint of stroke, valve thrombosis or re-intervention (hazard ratio 6.8, 95% CI 1.8-25.2, p<0.01) compared to controls. Immobile leaflet immediately post-bioprosthetic valve implantation is frequently under-recognised intraoperatively and appears to be associated with early bioprosthetic dysfunction and worse clinical outcome.

Blood flow energy loss: a predictor for the recovery of left ventricular function after bioprosthetic aortic valve replacement.

It is difficult to estimate the improvement in left ventricular (LV) function after aortic valve replacement (AVR). The present study aimed to evaluate whether energy loss (EL) can predict the postoperative LV function after AVR. Nine patients who underwent AVR with a bioprosthetic valve were enrolled in the present study. Porcine prostheses were used in 5 patients and bovine pericardial prostheses were used in 4 patients. The aortic flow pattern was visualized and EL and cardiac output (CO) were measured using 4-dimensional flow magnetic resonance imaging from the LV to the descending aorta; the EL/CO ratio in the extracted area was calculated as total EL/CO ratio. With a porcine valve, a severe helical flow was observed in the ascending aorta during the holosystolic phase. In contrast, with a bovine pericardial valve, straight transvalvular aortic flow was observed in the early systolic phase and 2 large vortical flows occurred on both sides of the greater and lesser curvature of the ascending aorta after the mid-systolic period. The total EL/CO ratio was strongly correlated with LV ejection fraction improvement after AVR (r = 0.74, P = 0.02). The aortic flow pattern is different between the porcine valve and bovine pericardial valve. The total EL/CO ratio is a valuable tool for evaluating the postoperative LV ejection fraction improvement after AVR. Optimization of total EL/CO ratio would have potential to improve haemodynamic performances after AVR.

Discussion

Discussion

Porcine vs Bovine Bioprosthetic Aortic Valves: Long-Term Clinical Results

Previous studies have reported superior hemodynamic performance with bovine bioprosthetic aortic valves compared with porcine valves. However, conflicting results mean the long-term effect on survival is not well known. The aim of this study was to examine long-term survival, rate of aortic valve reoperations, and heart failure hospitalizations after surgical aortic valve replacement (AVR) with porcine vs bovine bioprosthetic valves. This was a population-based cohort study including all patients who had undergone AVR in Sweden from 1995 to 2012, with or without concomitant coronary artery bypass grafting. Patients were identified through the SWEDEHEART (Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies) registry. Baseline and outcome data were gathered from national registries. Propensity scores and inverse probability of treatment weighting were used to control for intergroup differences. Analyses accounted for competing risk of death when appropriate. A total of 12,845 patients underwent AVR with porcine (n= 4198) or bovine (n= 8647) prostheses. We found a small but significant difference in mortality favoring porcine prostheses: 78% vs 76%, 47% vs 43%, and 17% vs 15% at 5, 10, and 15 years, respectively (hazard ratio, 0.90; 95% confidence interval, 0.85-0.96). Porcine prostheses were associated with an increased risk of reoperation (hazard ratio, 1.48; 95% confidence interval, 1.11-1.98), but no difference in the risk of heart failure hospitalization. Results were similar in patients who underwent isolated AVR. Consistent with previous reports, we found that patients receiving porcine prostheses had a higher rate of reoperation compared with bovine prostheses. However, porcine prostheses were associated with improved long-term survival compared with bovine prostheses.

Surgical Options for Aortic Root Replacement in Destructive Endocarditis.

ObjectiveTo analyze patients’ preoperative characteristics, surgical data, postoperative courses, and short- and long-term outcomes after implantation of different full-root prostheses for destructive aortic valve endocarditis.MethodsBetween 1999 and 2018, 80 patients underwent aortic root replacement due to infective endocarditis in our institution. We analyzed the abovementioned data with standard statistical methods.ResultsThe Freestyle stentless porcine prostheses were implanted in 53 (66.25%) patients, biological valve conduits in 13 (16.25%), aortic root homografts in nine (11.25%), and mechanical valve conduits in five (6.25%). There were no significant preoperative differences between the groups. The incidence of postoperative complications and intensive care unit length of stay did not differ significantly between the groups. The 30-day mortality rate was low among Freestyle patients (n=8, 15.1%) and high in the mechanical conduit cohort (n=3, 60%), though with borderline statistical significance (P=0.055). The best mean survival rates were observed after homograft (13.7 years) and stentless prosthesis (8.1 years) implantation, followed by biological (2.8 years) and mechanical (1.4 years) conduits (P=0.014). The incidence of reoperations was low in the mechanical conduit group (0) and stentless bioroot group (n=1, 1.9%), but two (15.4%) patients with biological conduits and three (33.3%) patients with homografts required reoperations in the investigated follow-up period (P=0.005).ConclusionIn patients with the destructive form of aortic valve endocarditis, homografts and stentless porcine xenografts offer better survival rates than stented valve conduits; however, the reoperation rate among patients who received homograft valves is high.

OUTCOMES OF STENTLESS BIOPROSTHETIC AORTIC VALVES: THE ALBERTA EXPERIENCE

Stentless aortic bioprostheses have demonstrated hemodynamic benefits including laminar flow and larger effective orifice area. However, data on the long-term performance of this valve design is limited relative to conventional stented bioprostheses. As well, many stentless valves were implanted via full-root replacement, potentially making reoperation more technically demanding and higher risk. Alberta’s two cardiac centres have one of the largest experiences with stentless valves in North America. The objective of this study was to compare stentless and stented bioprostheses to assess long-term outcomes, including results of reoperative surgery. Two large prospectively maintained databases, including the province-wide APPROACH database, were used to create a retrospective consecutive cohort. Patients undergoing bioprosthetic aortic valve replacement (AVR) from January 2002 to March 2014 were included. All operations were performed at the Foothills Medical Centre (Calgary) or the University of Alberta Hospital (Edmonton). Patient characteristics, surgical details and clinical outcomes were compared between stentless and stented valve cohorts. During the timeframe, 3959 Albertans underwent AVR with either stentless (n=1238) or stented (n=2721) bioprotheses. The 2 cohorts were similar overall, though patients in the stentless group were younger (67.0±12.5 vs. 70.8 years; p<0.0001), and had higher incidence of COPD and dyslipidemia. The majority of stentless valves were Medtronic Freestyle porcine prostheses (n=992; 80.1%). Over the 12-year period, there was no difference in survival between the groups. Table 1 outlines reoperative outcomes. During a mean follow-up of 7.9±2.6 vs 5.3±2.4 years (stentless vs stented), there was a similar rate of AVR-related reoperation in both groups (4.3% vs. 8.6%, stentless vs. stented; p=0.32). Both reoperative cohorts demonstrated similar crossclamp times and cardiopulmonary bypass times. There was no difference in perioperative mortality at reoperation (7.6 vs 6.4%, stentless vs. stented; p=0.22). Reoperation in both groups were due to multiple reasons, but most common was structural valve deterioration (Figure 1). This study presents the largest reported cohort of sutureless valve patients. Outcomes suggest no significant difference in survival or rate or reoperation between stented and stentless valves over a 12-year follow-up period. Furthermore, reoperation in patients with stentless valves, though thought to be accompanied with higher technical difficulty and risk, does not demonstrate increases in crossclamp times, cardiopulmonary bypass times, perioperative mortality or all cause mortality. In the future, we hope to both extend the study period to determine differences in incidence of structural valve deterioration together with mechanism of failure.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Survival after Aortic Valve Replacement with Bovine or Porcine Valve Prostheses: A Systematic Review and Meta-Analysis.

Bovine and porcine bioprostheses are commonly used for surgical aortic valve replacement. It is unknown if the long-term survival differs between the two valve types.We performed a systematic review and meta-analysis to compare survival in patients who underwent aortic valve replacement and received a bovine or a porcine prosthesis. We performed a systematic search of Medline, Embase, Web of Science, and the Cochrane Library. Cohort studies that compared survival between patients who underwent aortic valve replacement and received either a bovine or a porcine bioprosthesis and that reported overall long-term survival with hazard ratio (HR) and 95% confidence interval (CI) were included. Two authors independently reviewed articles considered for inclusion, extracted the information from each study, and performed the quality assessment. We performed a meta-analysis using a random effects model to calculate the pooled HR (95% CI) for all-cause mortality. We did sensitivity analyses to assess the robustness of our findings. Seven studies published between 2010 and 2015 were included, and the combined study population was 49,190 patients. Of these, 32,235 (66%) received a bovine, and 16,955 (34%) received a porcine bioprosthesis. There was no significant difference in all-cause mortality between patients who received a bovine compared with a porcine bioprosthesis (pooled HR 1.00, 95% CI: 0.92-1.09). Heterogeneity between studies was moderate (55.8%, p = 0.04). This systematic review and meta-analysis suggest no difference in survival between patients who received a bovine versus a porcine bioprosthesis after aortic valve replacement. Our study provides valuable evidence for the continuing use of both bovine and porcine bioprosthetic valves for surgical aortic valve replacement.

Tricuspid valve replacement: results of an orphan procedure - which is the best prosthesis?

Replacement of the tricuspid valve is uncommon. Prostheses specifically designed for this position are not available. Bovine, porcine as well as mechanical valve prostheses are currently used, however, the most suitable prosthesis type has not been defined. We retrospectively analyzed all consecutive patients who underwent tricuspid valve replacement (TVR) at the Medical University of Vienna from 1996 to 2014. Baseline patient characteristics, prosthesis type, and postoperative outcome data were collected. A total of 58 patients underwent TVR. Forty-one patients (71%) received biological (18 bovine, 23 porcine), and 17 patients (29%) mechanical prostheses. One-year survival (70.2% vs. 76.5%, P=0.18), and freedom from reoperation at one year (86.3% vs. 94.1%, P=0.35) was not significantly different bioprostheses and mechanical valves. Freedom from reoperation rates for bovine versus porcine prostheses (one-year: 88.2% vs. 84.4%, P=0.145) were also not significantly different. However, three bovine prosthesis had to be reoperated due to high-grade central regurgitation without any signs of endocarditis or structural valve degeneration. There is a lack of clinical trials on tricuspid valve replacement and no specific guidelines for the choice of prosthesis. In the current study we have not identified significant differences in mortality between mechanical and biological valves. However, bovine prostheses seem less suitable for the tricuspid position due to the high closing volume with consecutive severe postoperative regurgitation.

Prótesis pulmonar porcina versus yugular bovina para reparar el tracto de salida del ventrículo derecho en menores con cardiopatía congénita

IntroductionIn some patients, in childhood, it may be necessary to recover the valve function of the right ventricular outflow tract, a sequel of the primary repair of their congenital heart disease. ObjectiveTo compare the outcomes of bovine jugular (YB) -Contegra® versus porcine prosthesis (PPP), implanted in patients under 18 years old. MethodsThe study included all patients under 18 years old and re-operated on between January 2003 and June 2015 after primary surgery right ventricle outflow tract, and in whom a YB/PPP was implanted. Prosthetic valve dysfunction criteria were, surgical/percutaneous re-intervention, and a gradient>50mmHg or severe prosthetic regurgitation. Statistical analysis was performed using SPSS 20.0. ResultsThere were 21 PPP implanted in 20 patients, and 15 YB in 15 patients. The study included 60% males. The most common primary congenital heart disease was Fallot. The groups were not exactly homogeneous. Of the 24 preoperative variables, 11 of them showed statistically significant differences (P<.05). These included a higher percentage of transannular surgery, indication of pulmonary regurgitation surgery, ventricular dilation, and dysfunction in the PPP group.Of the 15 perioperative variables, there were significant differences in, the mean age at implantation: 8.8±4.4 years YB versus 11.8±4 PPP (P=.044); valve diameter (P<.001) lower in YB. Need of aortic cross clamping (P=.015) however, higher in YB.There was no in-hospital or late mortality. Follow-up: 4.8 years YB versus 2.4 PPP (P=.046). Other postoperative variables with significant differences: transprosthetic gradient, residual prosthetic regurgitation, prosthetic dysfunction, all higher in YB group. ConclusionsWith prudence imposed by differences in follow-up time and type of previous surgery in both cohorts, it seems reasonable to choose a PPP to recover functionality of the right ventricle outflow tract.The YB could be used when a conduit is essential.

Long-term results of the Medtronic Mosaic porcine bioprosthesis in the aortic position

We addressed the long-term results of the Medtronic Mosaic porcine prosthesis in the aortic position. From 1994 to 2004, 1007 Mosaic valves were used for aortic valve replacement. The data were prospectively collected, retrospectively analyzed, and stratified according to patient age at surgery (group 1, <70 years; group 2, 70-75 years; group 3, 76-80 years; and group 4, >80 years), using both actual (cumulative risks) and actuarial methods. Operative mortality was 5% (valve related in 14%). Globally, 8122.17 patient-years were available (average follow-up, 8.5 ± 3.9 years; 99.8% complete). Overall, survival at 15 years was lower among the elderly strata (P < .0001). Freedom from structural valve deterioration (SVD) was 95.1% (actual) and 86.3% (actuarial; 24 SVD events). Survival free from SVD was lower in group 1 (P = .003) but comparable among the other groups. Overall freedom at 15 years from the composite endpoint (any valve-related adverse events) was 82% (actual) and 71.3% (actuarial). No meaningful intergroup differences were found in survival free from the composite endpoint (P = .9) or freedom from valve-related mortality (P = .8). Younger patients at surgery did not show accelerated degeneration. No relationship could be established between prosthetic size and SVD. The implantation of a bioprosthesis in patients aged 70 years or older remains fully justified. The rate of SVD was higher in younger patients, mainly owing to their greater life expectancy. Patients younger than 70 can receive a bioprosthesis, provided that the correct information regarding the expected durability has been provided. This might be better accomplished through the actual methodology.

Do Pericardial Bioprostheses Improve Outcome of Elderly Patients Undergoing Aortic Valve Replacement?

Pericardial bioprostheses have favorable echocardiographic hemodynamics in the aortic position compared with porcine valves; however, there are few data comparing clinical outcomes. Our objective was to assess the late results of the two valve types. We reviewed 2,979 patients aged 65 years or older undergoing aortic valve replacement with pericardial (n=1,976) or porcine (n=1,003) prostheses between January 1993 and December 2007. The most common pericardial prostheses were Carpentier-Edwards Perimount and Mitroflow, and the most common porcine valves were Medtronic Mosaic, Carpentier-Edwards, Hancock modified orifice, and St. Jude Biocor. Follow-up extended to a maximum of 16 years (mean, 5.2±3.5 years). Survival at 5, 10 and 12 years was, respectively, 68%, 33%, and 21% overall, was 68%, 30%, and 16% for patients with pericardial bioprosthesis, and was 69%, 38% and 27% for the porcine group. In a multivariate model, long-term survival was reduced in patients with diabetes, renal failure, prior myocardial infarction, congestive heart failure, and older age, but late survival was not higher in the pericardial valve group. Overall freedom from reoperation was 96%, 92%, and 90% at 5, 10, and 12 years, and freedom from explant was 98%, 96%, and 94% during the same period. The reason for explant was structural valve deterioration in 50 patients (2%). Despite the better hemodynamic performance documented in prior investigations, pericardial valves do not confer any survival advantage over porcine valves in patients aged 65 years or older undergoing aortic valve replacement.

Percutaneous Closure of a Left Ventricular Outflow Tract Pseudoaneurysm Causing Extrinsic Left Coronary Artery Compression by Transseptal Approach

A 44-year-old man underwent aortic valve replacement with a porcine bioprosthesis 21 years ago for infective endocarditis complicated by a cerebral mycotic aneurysm and intracranial bleeding. Nine years ago, he had a second aortic valve replacement with a mechanical bileaflet tilting-disk prosthesis because of porcine prosthesis degeneration. No pseudoaneurysm was noted on the operative report. Six months ago, he developed angina and had a positive stress test for ischemia. Angiography showed severe left main coronary artery (LM) stenosis, which was treated with intravascular ultrasound–guided percutaneous coronary intervention with a zotarolimus-eluting stent. Two months ago, he again developed angina. Follow-up angiography and intravascular ultrasound revealed severe in-stent restenosis in the proximal third of the LM and systolic narrowing of the distal third, suggestive of extrinsic compression (Figure 1 and online-only Data Supplement Movie 1). In-stent restenosis was treated at that time with a sirolimus-eluting stent. A transesophageal echocardiogram revealed a large pseudoaneurysm lateral to the aortic root; color …

Stentless porcine valves in the right ventricular outflow tract: improved durability?☆

Stentless porcine valves are commonly used for aortic valve replacement in adults, yet their long-term performance in the right ventricular (RV) outflow tract is unknown. We evaluated intermediate-term performance of stentless porcine valves in the RV outflow tract in 150 children and adults over a 10-year period. We retrospectively reviewed data on all patients undergoing placement of a pulmonary valve or RV-PA conduit with a stentless porcine prosthesis (>/=19 mm) from 1998 to 2008. Valvar function was assessed with echocardiography. Freedom from reintervention (explantation or catheter-based intervention) was determined by actuarial methods. A stentless porcine prosthesis was placed in the pulmonary position in 150 patients with a median weight and age of 50.1 kg (range 9.8-127) and 15.8 years (range 1.4-55), respectively. There were three early deaths (2%) and no late deaths. Actuarial freedom from reintervention was 100% at 1 year and 95.5% at 5 years. Peak transvalvar gradient at 1 and 5 years was 13+/-12 mmHg and 25+/-11 mmHg, respectively. At last follow-up no patient had severe insufficiency (PI), five patients had moderate PI and the remainder mild or no PI. Stentless porcine valves function well in the pulmonary position over the intermediate-term and are associated with low rates of reintervention in patients requiring a >19 mm valve or valved conduit. Longer-term follow-up and comparison with other alternatives will be necessary to determine if these valves are superior to commonly used allograft or bovine jugular venous valved conduits.

Twenty-Year Experience With the St. Jude Medical Biocor Bioprosthesis in the Aortic Position

The purpose of this study was to evaluate the long-term performance of the St. Jude Medical Biocor stented porcine prosthesis in the aortic position. From January 1985 to December 1996, 455 patients admitted for aortic valve replacement were consecutively enrolled in this study. The mean age was 72.5 +/- 9 years, 18 patients (3.5%) had had previous cardiac surgery, and coronary artery bypass grafting was performed in 171 patients (37.6%). Follow-up was complete in 99.6%; up to 21 years were covered. Actuarial event-free rates are given as mean +/- standard error and adverse events were classified according to the guidelines for reporting morbidity and mortality after cardiac valvular operations. Cumulative follow-up time was 3,321 patient-years with a mean follow-up of 8.2 years. The actuarial survival rate after 20 years was 9.4% +/- 2.8%. The actuarial rates for freedom from structural valve deterioration were 93.1% +/- 1.7% at 10 years, 88.4% +/- 3.5% at 15 years, and 70.3% +/- 10.9% at 20 years. The actuarial rates for freedom from reoperation due to structural valve deterioration were 91.9% +/- 1.6% at 10 years, 90.6% +/- 2.1% at 15 years, and 86.5% +/- 4.5% at 20 years. This study presents one of the largest series of St. Jude Medical Biocor aortic valves in the world. Results indicate an age-dependent risk of structural valve degeneration beginning as soon as 7 years postoperatively for patients below the age of 65 years, but show a low overall incidence of valve-related complications and excellent durability.

Evaluation of Bioprosthetic Valve for Small Aortic Root in Elderly Patients

The hemodynamics of stentless bioprostheses are superior to those of mechanical valves, especially for patients with a small aortic root. Between March 1999 and July 2001, we implanted 18 Freestyle stentless porcine valves using our technique of repeated division of the space by halving the distance. Seven patients received 19-21-mm valves and 11 received 23-25-mm valves. Clinical data and early and midterm outcomes of both groups were compared. The mean preoperative echocardiography gradient of the small valve group was 84.7 mm Hg, and when discharged from hospital, the mean gradient was 14.8 mm Hg. One operative death was encountered due to arrhythmia. This stentless porcine prosthesis has excellent hemodynamics and can be implanted safely and easily, even in elderly patients with a small aortic root, using our suture technique.

Normal coronary flow reserve after stentless aortic valve replacement – results from a prospective, randomized study

Introduction: Coronary perfusion is impaired in patients with aortic stenosis. Valve replacement (AVR) leads to improvement but not complete restoration. The following study investigates coronary flow and flow reserve in patients undergoing biological valve replacement with stentless or stented porcine prostheses in a prospective, randomized study.

The decrease of degeneration rate by means of a permanent antithrombotic theraphy 16 and more years after the biological aortic valve replacement

Aims: In view of the main deficiency of biological valve prostheses – their frequent degeneration, we analysed the impact of a permanent post-operative antithrombotic therapy (PPATT) after the aortic valve replacement with biological prostheses (BAVP) on their degeneration rate among 142 patients who had been operated on with aortic valve replacement with biological prostheses (141 Carpentier-Edwards porcine prostheses and 1 allograft aortic valve) between July 1976 and December 1980 in our clinic.