Freestyle Stentless Bioprosthesis Research Articles

Freestyle Aortic Bioprostheses in Patients 60 Years old and Younger

Evaluate outcomes of the Freestyle stentless aortic bioprosthesis in patients 60 years old and younger. All patients, 60 years old and younger, between January 1, 1998 to December 31, 2015 who underwent implantation of a Freestyle aortic valve at a single institution were reviewed. Medical records and telephone interviews were utilized for data collection. 515 patients were identified with an average age of 51.3 years. Mean follow up was 11.1 years. 225 full root replacements and 290 subcoronary implants were performed. Overall survival, including patients with concomitant procedures, at 15 years was 63.7% (95% CI 58.3-68.5). Isolated subcoronary implants (58%,167/290) had a 15-year survival of 71.6% (95% CI 62.6-78.7) vs 78.4% (95% CI 69.7, 84.9) for isolated root replacements (63%,141/225) which was not statistically significant (P=0.397). No significant difference in operative SVD at 15 years occurred between full root replacements 37.6% (95% CI 27.2-50.2) vs subcoronary implants 39.4% (95% CI31.1, 49.0). 110 patients required reoperation solely for intrinsic SVD. 93% (102/110) failed due to aortic insufficiency. Of reoperative interventions for SVD, 37% (41/110) of patients required urgent reoperation and 4.5% (5/110) required emergent reoperation. Pseudoaneurysms developed in six of the full root replacements. Freestyle aortic valves have a high rate of acute failure requiring urgent or emergent reintervention in patients 60 years old and younger. This has led our group to shift practice away from their implantation.

Structural abnormalities after aortic root replacement with stentless xenograft

ObjectiveIn complex and high-risk aortic root disease, the porcine Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, Minn) is an important surgical treatment option. We aimed to determine prevalence and clinical effect of structural and functional abnormalities after full-root Freestyle implantation. MethodsOur cross-sectional 2-center study combined with clinical follow-up included 253 patients with full-root Freestyle bioprostheses implanted from 1999 to 2017. Patients underwent transthoracic echocardiography (TTE) and contrast-enhanced, electrocardiogram-gated 4-dimensional cardiac computed tomography (4DCT) at median age 70 (interquartile range, 62-75) years. After 4DCT, clinical follow-up continued throughout 2018. Median follow-up was 3.3 years before 4DCT and 1.4 years after. ResultsWe identified abnormalities in 46% of patients, including pseudoaneurysms (n = 32; 13%), moderate or severe coronary ostial stenosis (n = 54; 21%), and moderate-severe leaflet thickening or reduced leaflet motion (n = 51; 20%). TTE only identified 1 patient with pseudoaneurysm. After 4DCT, the unadjusted hazard ratio for surgical reintervention among patients with abnormal 4DCT was 4.2 (95% confidence interval, 1.2-15.3), in all, 10% required a reintervention. 4DCT abnormalities were associated with a statistically nonsignificant increased risk of death, stroke, or myocardial infarction (hazard ratio obtained using Cox proportional hazards regression analysis, 2.4; 95% confidence interval, 0.7-7.6). In all, 4.0% died, 3.6% had a myocardial infarction, and 2.0% had a stroke. ConclusionsStructural and functional abnormalities of the aortic root are frequent after Freestyle implantation and TTE appears to be insufficient for follow-up. Abnormalities might be associated with increased risk of reintervention and potentially adverse clinical outcomes. Longer follow-up and larger study populations are needed to further clarify the clinical implications of abnormalities identified with 4DCT.

Long Term Outcomes of Freestyle Stentless Aortic Bioprosthesis: A Single Center Experience.

The study is presenting our long-term clinical results after freestyle stentless aortic root bioprosthesis replacement in patients with severe aortic insufficiency with ascending aortic aneurysm. Seventy-seven patients with ascending aortic aneurysms and aortic valve insufficiency underwent a total root replacement procedure using a stentless "Freestyle" valve (Medtronic Inc., Minneapolis, Minnesota). There were 50 (64.9%) men and 27 (35.1%) women. Mean age was 68.7 ± 11.1 years. The surgical procedure used a complete root replacement. Concomitant procedures included coronary artery bypass grafting in 15 (19.5%) patients. The mean cardiopulmonary bypass time was 130.3 ± 26.4 minutes and total aortic cross clamp time was 99.5 ± 23.6 minutes. Hospital mortality was 2.6%. The median follow-up time was 11.2 years. The 5- and 10-years freedom from aortic valve reoperation were 97.4 ± 1.2% and 93.4 ± 4.9%, respectively. During 10 years follow up, there were 14 late deaths; 4 deaths were cardiac, and 10 deaths were noncardiac. Valve-related deaths were attributable to thromboembolism in 1 patient, endocarditis in 2 patients, and congestive heart failure in 1 patient. The freestyle stentless aortic root bioprosthesis offered good clinical outcomes, in terms of survival and structural valve deterioration. The Freestyle valve is a viable option for use in patients undergoing bioprosthetic aortic valve replacement and expected desire for long-term durability.

Pregnancy and transcatheter aortic valve replacement in a severely stenotic Freestyle full aortic root stentless bioprosthesis

Symptomatic degenerative prosthetic aortic valve stenosis during pregnancy represents a significant risk to both mother and fetus, and until recently, surgical aortic valve replacement (SAVR) during pregnancy was often the only choice for women opting to continue pregnancy. However, symptomatic severe stenosis in a pregnant woman with a degenerated full aortic root Freestyle stentless bioprosthesis (FSB) and reimplanted coronary arteries presents additional complexities that require an alternative surgical approach. In this case report, we describe the first successful transcatheter aortic valve replacement (TAVR) in SAVR for a severely stenotic degenerative FSB in a pregnant woman and subsequent delivery of a healthy infant several months later. TAVR in SAVR of a severely stenotic aortic FSB should be considered as a surgical option in symptomatic pregnant women. Short-term and long-term implications for future pregnancy should be discussed by a multidisciplinary team and with the patient.

Reinterventions after freestyle stentless aortic valve replacement: an assessment of procedural risks.

OBJECTIVESRepeat aortic valve interventions after previous stentless aortic valve replacement (AVR) are considered technically challenging with an increased perioperative risk, especially after full-root replacement. We analysed our experience with reinterventions after stentless AVR.METHODSA total of 75 patients with previous AVR using a Freestyle stentless bioprosthesis (31 subcoronary, 15 root-inclusion and 29 full-root replacement) underwent reintervention in our centre from 1993 until December 2018. Periprocedural data were retrospectively collected from the department database and follow-up data were prospectively collected.RESULTSMedian age was 62 years (interquartile range 47–72 years). Indications for reintervention were structural valve deterioration (SVD) in 47, non-SVD in 13 and endocarditis in 15 patients. Urgent surgery was required in 24 (32%) patients. Reinterventions were surgical AVR in 16 (21%), root replacement in 51 (68%) and transcatheter AVR in 8 (11%) patients. Early mortality was 9.3% (n = 7), but decreased to zero in the past decade in 28 patients undergoing elective reoperation. Per indication, early mortality was 9% for SVD, 8% for non-SVD and 13% for endocarditis. Aortic root replacement had the lowest early mortality rate (6%), followed by surgical AVR (13%) and transcatheter AVR (25%, 2 patients with coronary artery obstruction). Pacemaker implantation rate was 7%. Overall survival rate at 10 years was 69% (95% confidence interval 53–81%).CONCLUSIONSRepeat aortic valve interventions after stentless AVR carry an increased, but acceptable, early mortality risk. Transcatheter valve-in-valve procedures after stentless AVR require careful consideration of prosthesis leaflet position to prevent obstruction of the coronary arteries.

Twenty-year experience with stentless biological aortic valve and root replacement: informing patients of risks and benefits.

The aim of this study was to provide predictive data on the performance of the Freestyle stentless bioprosthesis that can be used to support and improve the shared decision-making process of prosthetic valve choice for aortic valve replacement. Between 1993 and 2014, 604 patients received the Freestyle stentless bioprosthesis (143 subcoronary, 58 root inclusion and 403 full-root replacement). Perioperative data were collected retrospectively, and follow-up data were collected prospectively from 2015. Follow-up was 96% complete (median 4.3 years), with 114 (19%) patients having a follow-up period exceeding 10 years. A competing risks regression model was developed to predict the probability of mortality, structural valve deterioration (SVD) and reoperation for other causes than SVD. The median age of patients was 64 years, 91 (15%) patients had undergone previous aortic valve replacement and 351 (58%) underwent concomitant procedures. The 15-year probability of SVD, reoperation for other causes and death were 16.9%, 8.1% and 47.7%, respectively. Linearized occurrence rates for prosthesis endocarditis, thromboembolic events and bleeding were 0.5%, 0.9% and 0.1% per patient-year, respectively. The constructed predictive model, including age, renal function and implantation technique as significant covariates, had good to fair predictive performance up to 19 years. The Freestyle stentless bioprosthesis is an efficient prosthesis for aortic valve replacement or root replacement, with low incidences of SVD and valve-related events at long-term follow-up. The predictive model designed in this study can be used to fully inform patients about their expected individual trajectory after implantation of this prosthesis. This improves the shared decision-making process between patients and clinicians.

Early Outcomes for Valve-in-valve Transcatheter Aortic Valve Replacement in Degenerative Freestyle Bioprostheses

Transcatheter aortic valve replacement (TAVR) is used increasingly to treat bioprosthetic valve failure. A paucity of data exists regarding valve-in-valve (ViV) TAVR in degenerated Freestyle stentless bioprostheses (FSBs). This study sought to evaluate the feasibility and short-term outcomes of ViV TAVR in previously placed FSB. From October 2014 to September 2016, 22 patients at a single institution underwent ViV TAVR with a self-expanding transcatheter valve for a failing FSB. Patient baseline characteristics and clinical outcomes data were collected retrospectively and entered into a dedicated database. The mean patient age was 74 ± 9 years, and the mean Society of Thoracic Surgeons' Risk score was 9.0 ± 7.4%. Ten patients presented with acute heart failure requiring urgent intervention. The most common mode of failure of the FSB was regurgitation caused by a flail or malcoapting leaflet. Seventeen (77%) patients had a modified subcoronary implantation, 3 (14%) had a full root replacement, and 2 (9%) had a root inclusion. Device success using a self-expanding transcatheter valve was 95%, all via transfemoral approach. The mean implant depth was 7 ± 3 mm. Thirty-day survival was 100%. No patient had more than mild paravalvular regurgitation at 30 days, and the permanent pacemaker rate was 9%. The mean hospital stay after intervention was 5 ± 2 days. ViV TAVR using a self-expanding transcatheter valve is safe, feasible, and can be used successfully to treat a failed FSB. Procedural challenges suggest referral to valve centers of excellence.

Freestyle stentless bioprosthesis for aortic valve therapy: 17-year clinical results.

Aortic valve replacement with stentless bioprostheses has been shown to produce lower aortic gradients than stented bioprostheses, thus facilitating left ventricular mass regression and preventing heart failure. We sought to determine the long-term results of stentless biological aortic valve replacement over a 17-year follow-up. Between 1996 and 2012, 2551 patients underwent isolated aortic valve replacement with a stentless prosthesis (Medtronic Freestyle) at a single center. The mean patient age was 72 ± 10 years, 55% were male, 24.1% were in New York Heart Association class I and II, 9.6% had undergone previous surgery, 18.1% had coronary artery disease, and 23.1% had diabetes. For the long-term follow-up, patients were contacted in writing and by telephone; follow-up was 96.3% complete, resulting in 11,546 patient-years. At 30 days, mortality (5.4%), renal failure (3.9%), myocardial infarction (0.7%), and stroke (1.4%) rates were acceptable. During long-term follow-up of 1-17 years, the bleeding rate (2.9%) was higher than the thromboembolic event rate (0.7%) despite 18.1% of patients being on oral anticoagulants. New pacemaker implantation (4.5%; 0.87 events/100 patient-years), neurological disorders (5%; 0.52 events/100 patient-years), valve insufficiency (0.7%; 0.16 events/100 patient-years), paravalvular leakage (0.4%; 0.09 events/100 patient-years) and reoperation due to valvular complications (0.7%; 0.38 events/100 patient-years) were rare. Long-term survival was 41.8% ± 1.6 after 10 years, 21.3% ± 2.3 after 15 years, and 12.1% ± 3.9 after 17 years. Long-term results after aortic valve replacement with stentless biological prostheses compare favorably with those obtained with stented bioprostheses.

Long Term Outcomes Following Freestyle Stentless Aortic Bioprosthesis Implantation: An Australian Experience

The Freestyle stentless bioprosthesis (FSB) has been demonstrated to be a durable prosthesis in the aortic position. We present data following Freestyle implantation for up to 10 years post-operatively and compare this with previously published results. A retrospective cohort analysis of 237 patients following FSB implantation occurred at five Australian hospitals. Follow-up data included clinical and echocardiographic outcomes. The cohort was 81.4% male with age 63.2±13.0 years and was followed for a mean of 2.4±2.3 years (range 0-10.9 years, total 569 patient-years). The FSB was implanted as a full aortic root replacement in 87.8% patients. The 30-day all cause mortality was 4.2% (2.0% for elective surgery). Cumulative survival at one, five and 10 years was 91.7±1.9%, 82.8±3.8% and 56.5±10.5%, respectively. Freedom from re-intervention at one, five and 10 years was 99.5±0.5%, 91.6±3.7% and 72.3±10.5%, respectively. At latest echocardiographic review (mean 2.3±2.1 years post-operatively), 92.6% had trivial or no aortic regurgitation. Predictors of post-operative mortality included active endocarditis, acute aortic dissection and peripheral vascular disease. We report acceptable short and long term outcomes following FSB implantation in a cohort of comparatively younger patients with thoracic aortic disease. The durability of this bioprosthesis in the younger population remains to be confirmed.

Early outcomes following pulmonary valve replacement with the medtronic freestyle stentless porcine root bioprosthesis

Early outcomes following pulmonary valve replacement with the medtronic freestyle stentless porcine root bioprosthesis

Outcomes following freestyle stentless aortic bioprosthesis implantation: The Australian experience up to 10 years

Outcomes following freestyle stentless aortic bioprosthesis implantation: The Australian experience up to 10 years

Bioprosthetic Valve Durability After Stentless Aortic Valve Replacement: The Effect of Implantation Technique

The Freestyle stentless bioprosthesis (FSB) (Medtronic Inc, Minneapolis, MN) is implanted using 2 techniques-subcoronary or aortic root replacement. Our objective was to determine whether the implantation technique had an impact on late reoperation for structural valve deterioration (SVD). Between 1993 and 2013, 531 patients underwent aortic valve replacement (AVR) or aortic root reconstruction with an FSB. The implantation technique was subcoronary in 430 patients (group S) and root replacement in 101 patients (group R). Median follow-up was 10.8 years for group S patients and 10.1 years for group R patients. The follow-up was complete in all patients. Mean age was 68.2 years in group S and 65.2 in group R (p= 0.001). In-hospital mortality was 3.5% and 5.0% in group S and group R, respectively (p= 0.56). Late reoperation was required in 60 (14.5%) hospital survivors in group S and 8 (8.3%) hospital survivors in group R. There were 36 reoperations in group S and 3 in group R for SVD. Freedom from reoperation for SVD was 94.6% and 76.7% at 10 and 15 years, respectively, in group S, and98.9% and 88.1% at 10 and 15 years, respectively, forgroup R (p= 0.04). The subcoronary technique was anindependent risk factor for late reoperation for SVD (p= 0.002). Implantation technique was not independently associated with in-hospital and long-term mortality. The Freestyle bioprosthesis implanted as a root replacement was associated with less reoperation for SVD over the long term compared with the subcoronary technique. However, the method of implantation has no influence on early and long-term survival.

Long-term results of Freestyle stentless bioprosthesis in the aortic position: A single-center prospective cohort of 500 patients

Stentless xenograft bioprostheses may be the future valve of choice for aortic valve replacement. The study aim was to investigate the long-term clinical outcome after aortic valve replacement with the Medtronic Freestyle bioprosthesis (Medtronic Inc, Minneapolis, Minn). Between April 1997 and November 2004, a total of 500 patients (mean age, 74.5±9.6 years; 52% were male) underwent aortic valve replacement with a Freestyle bioprosthesis, without population selection. The surgical procedure used a modified subcoronary technique in 479 patients and a complete root replacement in 21 patients, conducted with mini-extracorporeal circulation. Concomitant procedures included coronary artery bypass grafting in 122 patients (24%) and mitral valve repair/replacement in 11 patients. The mean cardiopulmonary bypass time was 98±26 minutes, and total aortic crossclamp time was 77±19 minutes. Operative mortality was 5.2%. The median follow-up time was 104.8±5.7 months. During this period, there were 224 deaths (n=122 cardiovascular and n=102 noncardiovascular deaths). The actuarial survivals from cardiovascular and valve-related mortality were 67%±3% and 70%±4%, respectively, at 10 years. Freedom from structural valve deterioration at 10 years was 94%±2%. The linearized structural valve deterioration incidence was 0.6% per patient/year. Multivariate Cox regression analysis revealed that older age, impaired renal function, and coronary artery disease were independent predictors of cardiovascular death. In the subgroup of patients aged less than 65 years at implantation (n=45), the actuarial cardiovascular survival was 83%±8% and freedom from structural valve deterioration was 89%±6% at 10 years. The use of the Freestyle bioprosthesis for aortic valve replacement resulted in good long-term cardiovascular survival and freedom from structural valve deterioration in this cohort regardless of age at implantation.

Long-Term Clinical Outcomes 15 Years After Aortic Valve Replacement With the Freestyle Stentless Aortic Bioprosthesis

The Freestyle stentless aortic root bioprosthesis has excellent hemodynamics and durability through 10 years. The purpose of this report is to present clinical outcomes in a large multicenter cohort through 15 years. The multicenter evaluation of the Freestyle valve began in 1992 at 21 centers in North America and Europe. In 1997, a long-term study continued, including 725 patients from 8 of the original centers; clinical outcomes data after 10 years have continued to be collected at 6 of 8 centers. Patient age was 71.7±7.9 years. There were 402 (55.4%) men and 323 (44.6%) women. Total follow-up was 5,491.2 patient-years. There were 52 late reoperations, with explant of the bioprosthesis in 47 cases. Respective 10- and 15-year survival was 46.2%±2.3% and 25.9%±3.2%; freedom from valve-related death was 94.9%±1.5% and 92.7%±3.5%; freedom from reoperation was 92.3%±1.8% and 80.7%±5.0%; and freedom from explant owing to structural valve deterioration was 96.5%±1.3% and 83.3%±4.8%. Increased age was associated with higher risks of all-cause mortality and valve-related mortality and lower risks of reoperation and explant caused by structural valve deterioration. In this long-term, multicenter, observational study, the Freestyle stentless aortic root bioprosthesis offered good clinical outcomes in terms of survival, freedom from valve-related mortality, freedom from reoperation, and freedom from structural valve deterioration. The Freestyle valve is a viable option for use in patients undergoing bioprosthetic aortic valve replacement and for anticipated desire for long-term durability.

Aortic Freestyle Stentless Bioprosthesis Leaflet Tears: Clinical Presentation and Diagnostic Accuracy of Echocardiography

Aortic Freestyle Stentless Bioprosthesis Leaflet Tears: Clinical Presentation and Diagnostic Accuracy of Echocardiography

Rupture of Valsalva Sinus After Aortic Root Replacement With Freestyle Stentless Bioprosthesis

We report a case of aortic wall rupture in a patient with a Medtronic Freestyle stentless bioprosthesis (Medtronic Inc, Minneapolis, MN) after full root implantation. A 68-year-old man who underwent aortic root replacement with a Freestyle bioprosthesis 12 years prior was found to have a large pseudoaneurysm originating from the ruptured noncoronary porcine aortic sinus. A reoperation for aortic root replacement was successfully performed. Despite excellent durability of porcine aortic root bioprostheses, several cases with a ruptured aortic wall have been reported. Degeneration of the elastic tissue and inflammatory reactions may be the main mechanism of this potentially catastrophic complication.

Root replacement with stentless Freestyle bioprostheses for active endocarditis: a single centre experience

Few studies have examined the use of stentless Freestyle bioprostheses in patients with active valve endocarditis (VE). The aim of this study was to evaluate outcomes of stentless Freestyle bioprostheses in patients undergoing full-root replacement. From February 2000 to June 2010, 180 patients with VE underwent cardiac surgery at our institution, of which 71 (39.5%) had prosthetic VE. Eighteen patients underwent full-root replacement with Freestyle bioprostheses: 3 patients (16%) had native aortic VE, 14 (78%) had aortic prosthetic VE and 1 (6%) had mitral and aortic prosthetic VE. Mean age was 66.7 ± 10.1, M/F: 6/12, mean logistic EuroSCORE 36.4 ± 21.6. Eight patients (42%) underwent concomitant procedures (two mitral valve replacements, three ascending aorta replacements, one coronary artery bypass grafting (CABG), one ventricular septal disease (VSD) repair, one CABG + ascending aorta + VSD repair). Two patients (11%) died in-hospital. At the median follow-up of 24 months (range 1-113 months), no death occurred and freedom from reoperation was 87.5% (2 patients for aortic root pseudo-aneurysm at 1 and 23 months). All patients are in NYHA functional class I and have satisfactory echocardiographic data (EF 54.3 ± 8%, peak and mean trans-prosthetic gradients 12 ± 6.7 mmHg and 7.5 ± 3.6 mmHg) with 100% freedom recurrence of VE. Our experience shows that root replacement with Freestyle stentless bioprostheses in patient with VE, is associated with low rates of early and mid-term mortality, good haemodynamic performance and low rates of valve-related morbidity as well as low recurrence of infection.

Long-Term Clinical and Echocardiographic Follow-Up of the Freestyle Stentless Aortic Bioprosthesis

Stentless aortic bioprostheses were designed to provide enhanced hemodynamic performance and potentially greater longevity. The present report describes the outcomes of patients with the Freestyle stentless bioprosthesis followed for ≤18 years. Between 1993 and 2011, 430 patients underwent primary aortic valve replacement with a Freestyle bioprosthesis in the subcoronary position. Mean age was 68.2 ± 8.2 years. All of the clinical and echocardiographic data were collected prospectively. Mean overall follow-up was 9.1 ± 4.4 years and was complete in all of the patients. In-hospital mortality was 3.5% (n=15). Overall, 10- and 15-year survival were 60.7% and 35.0%, respectively. Fifty-one patients required reoperation during follow-up, including 27 for structural valve deterioration (SVD). Overall, freedom from reoperation was 91.0% and 75.0% at 10 and 15 years, whereas freedom from reoperation for SVD was 95.9% and 82.3%, respectively. At 10 and 15 years, freedom from reoperation for SVD was 94.0% and 62.6% for patients <60 years of age and 96.3% and 88.4% for patients ≥60 years of age (P=0.002). The median time to explant for SVD was 10.7 years. SVD presented mostly as acute, severe aortic insufficiency attributed to leaflet tear (77.8%). The independent risk factors for reoperation for SVD were age <60 years (P=0.001) and dyslipidemia (P=0.02). Aortic valve replacement with the Freestyle bioprosthesis in a subcoronary position provides good long-term clinical and echocardiographic outcomes for patients >60 years of age. Severe aortic insufficiency with leaflet tear is the major mode of SVD leading to reoperation in these patients.

Stentless aortic bioprostheses: their role in the treatment of aortic endocarditis should not be underestimated

We read with great interest the comprehensive review article of Funder [1] on the clinical and experimental data surrounding the use of stentless aortic bioprostheses and fully agree with his conclusions. There is no doubt that they are ideal substitutes in patients with small aortic roots to prevent patient–prosthesis mismatch. In this context, they should be implanted in a ‘fullroot’ type of technique to minimize the postoperative aortic regurgitation that may occur due to distortion of the prosthesis [2] and to facilitate both prosthesis over-sizing and the optimization of haemodynamic results [3]. However, we were surprised that Funder did not comment on the value of stentless valves in the context of aortic endocarditis, particularly in patients with root abscesses and prosthetic valve endocarditis. Homografts have been the gold-standard for valve and root replacement in aortic endocarditis for a long time. Although they result in excellent haemodynamics and a low incidence of re-infection after surgery, the need for homograftrelated reoperation should not be underestimated and has been reported to be around 20% at 2 years, most often due to aortic regurgitation [4]. In addition, in these patients, for whom surgery is most often urgent, availability is limited, leading to delay in treatment. In 2003, Siniawski et al. [5] reported on their results using stentless bioprostheses in the setting of complex aortic endocarditis and made a comparison with their experience using homografts. Early mortality, freedom from re-infection and postoperative haemodynamics were not different between the two groups. However, they saw additional benefits of the stentless prosthesis, in that the surgery itself has a more standardized and therefore possibly easier technique. Moreover, limited availability, which may result in delayed surgery using homografts, is not an issue with stentless bioprostheses. If stentless valves are equivalent early after surgery, the question remains of how they compare with homografts in the longer term? Yacoub et al. [6] recently reported the outcomes of a prospective randomized trial including aortic root replacement using Freestyle stentless bioprostheses (Medtronic Inc., Minneapolis, MN, USA) and homografts. Over a median followup of 7.6 years, a significantly higher freedom from valve dysfunction in the stentless group (86 vs 37%) was noted. Consequently, reoperations due to structural valve degeneration were more common after homograft implantation (0 vs 10%). We conclude therefore, that the early outcome of stentless bioprostheses is comparable with homografts in patients suffering from aortic valve endocarditis. As long-term durability and freedom from reoperation are improved using stentless bioprostheses, and because their availability is not restricted, they are ideal substitutes, particularly in patients with complex aortic valve endocarditis.

Freestyle Aortic Root Bioprosthesis Is a Suitable Alternative for Aortic Root Replacement in Elderly Patients: A Propensity Score Study

The aim of this retrospective study was to compare the early and midterm clinical outcomes of aortic root replacement in elderly patients receiving the Freestyle stentless bioprosthesis (FSB) (Medtronic Inc, Minneapolis, MN) with younger patients receiving a mechanical valve conduit. From January 2001 to December 2010, 185 consecutive patients underwent aortic root replacement. Of these, 79 (43%) patients received the Freestyle bioroot (Medtronic Inc, Minneapolis, MN) (group F) and 106 (57%) patients received a mechanical valve conduit (group M). Target endpoints were 30-day mortality, 5-year survival, 5-year freedom from cardiac death, and 5-year freedom from major adverse valve-related and cardiovascular events (MAVCE) (cardiac death, cerebrovascular accident, myocardial infarction, heart failure, valve prosthesis dysfunction requiring reoperation, and thromboembolic and hemorrhagic events). A propensity score model was built to adjust the results according to preoperative and operative characteristics of both groups. Thirty-day mortality was similar in both groups (F group, 2.5% versus M group, 5.7%; p=0.407). Unadjusted analysis showed no differences between groups, whereas adjusted analysis showed a significantly higher 5-year freedom from cardiac death and MAVCE in group F (group F, 98.6±1.9 versus group M, 88.0%±3.0%; p=0.038; group F, 97.4%±2.6% versus group M, 81.2%±3.6%; p=0.010). Multivariate analysis confirmed a significantly higher risk for 5-year MAVCE in patients who did not undergo implantation with the Freestyle bioprosthesis (hazard ratio [HR], 6.87; 95% confidence limit [CL], 1.43-15.09; p=0.016). In elderly patients, the FSB seems to be as safe as mechanical composite grafts in the perioperative period but results in superior freedom from MAVCE at 5 years postoperatively.