Freestyle Aortic Bioprosthesis Research Articles

Outcomes after transcatheter valve-in-valve implantation using a balloon-expandable Edwards Sapien valve in patients with degenerated Freestyle aortic bioprosthesis.

Transcatheter aortic valve-in-valve implantation (ViV TAVI) in degenerated Medtronic Freestyle aortic bioprosthesis (FSB) has been reported as being technically challenging. This study sought to evaluate procedural data and outcomes after ViV TAVI using a balloon-expandable Edwards valve in patients with failed FSB. Between August 2014 and December 2020, twenty-seven consecutive patients underwent ViV TAVI for symptomatic FSB failure at our institution using a Sapien XT (n=1) and Sapien 3 (n=26) valve, respectively. Endpoints were defined according to the Valve Academic Research Consortium-2 (VARC-2) criteria and were retrospectively analyzed. Mean patient age was 75.7±8.2 years (female n=5, male n=22); Society of Thoracic Surgeons Predicted Risk of Mortality score was 7.3%±6.2%. ViV implantation with correct positioning of the Edwards Sapien valve within the FSB was successful in all cases. Intraprocedural transesophageal echocardiography revealed none/trace paravalvular regurgitation in twenty-five patients (92.6%), mild paravalvular regurgitation was present in two patients (7.4%). Neither of the patients had a mean gradient ≥20.0 mmHg excluding significant patient-prosthesis mismatch. Three early deaths (≤thirty days) occurred resulting in a device success rate of 88.8%. One-year and three-year survival rates for patients alive beyond day thirty after ViV TAVI were 95.8% and 70.0%, respectively. ViV TAVI with Edwards Sapien valves lead to acceptable functional results in high-risk patients with degenerated FSB but early complications must be considered particularly during hospital stay.

Transcatheter valve-in-valve implantation versus surgical redo aortic root replacement in patients with degenerated freestyle aortic bioprosthesis.

Transcatheter aortic valve-in-valve implantation (ViV TAVI) represents a new treatment option for patients with degenerated aortic bioprosthesis. Comparative data to redo surgical aortic valve replacement (redo SAVR) are limited. We investigated feasibility and outcome of ViV TAVI versus redo SAVR in patients with symptomatic degenerated Medtronic Freestyle aortic bioprosthesis (FSB). Between January 2002 and February 2020, 25 patients with failed FSB underwent ViV TAVI and 10 patients with failed FSB underwent redo SAVR. Endpoints were defined according to the Valve Academic Research Consortium-2 (VARC-2) criteria. Age and logistic EuroSCORE II were higher in patients with ViV TAVI (75.4± 1.7 vs. 62.9± 5.1 years, p= .019; 11.5± 1.6 vs. 5.6± 5.6%, p= .007). Valve implantation was successful in all cases. Mean transvalvular pressure gradients were significantly lower in patients with redo SAVR than ViV TAVI (7.6± 1.0 vs. 10.3± 0.8 mmHg, p= .037). Aortic valve regurgitation was absent in 91% and 100% of patients with ViV TAVI and redo SAVR, respectively. Thirty-day mortality rates were 12% in the ViV TAVI cohort versus 0% in the redo SAVR cohort (p= .542). Within the first year after hospital discharge, one patient after ViV TAVI had redo surgical intervention. ViV TAVI and redo SAVR lead to excellent functional results in patients with degenerated FSB. Post-procedural early complications must be considered particularly in patients with ViV TAVI because of higher clinical risk profiles.

Aortic Root Replacement for Pseudoaneurysm Arising from Freestyle Aortic Bioprosthesis.

A 70-year-old female presented with a new systolic murmur and shortness of breath three years after undergoing aortic root replacement using a 27-mm Medtronic Freestyle® stentless full root bioprosthesis (Medtronic, Inc., Fridley, Minnesota, USA). A large complex aortic root pseudoaneurysm was identified on contrasted computed tomography of the chest and transesophageal echocardiogram. We describe the redo aortic root replacement using a customized Dacron tube/valve composite graft with a proximal "skirt" and a modified Cabrol technique.

Traumatic Dehiscence of Medtronic Freestyle Stentless Bioprosthesis

We report a case of deceleration injury causing traumatic dehiscence of a Medtronic Freestyle aortic bioprosthesis (Medtronic Inc, Minneapolis, MN) in a 70-year-old patient 5 years after a total root reconstruction. The patient presented with progressive exertional dyspnea 6 months after a significant impact during a hockey game. Intraoperatively, there was a posterior dehiscence of the proximal suture line and almost complete tear of the left coronary leaflet. At reoperation, the patient underwent reconstruction of the aortic root and Bentall procedure with a size 23 mechanical aortic valved conduit.

Invited commentary

A decade of extensive clinical investigations has followed the early reports of more favorable left ventricular (LV) mass regression and functional remodeling with stentless rather than stented aortic valve replacement (AVR). In contrast to the majority of previous reports, two large randomized clinical trials have recently reported insignificant differences in LV mass regression or valve hemodynamics, or both, between stentless and stented AVR. Therefore, the meta-analysis reported by Kunadian and colleagues [1Kunadian B. Vijayalakshmi K. Thornley A.R. et al.Meta-analysis of valve hemodynamics and left ventricular mass regression for stentless versus stented aortic valves.Ann Thorac Surg. 2007; 84: 73-79Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar] has been a timely important contribution, whereas we try to reconcile conventional wisdom with these new findings. The authors analyzed 10 randomized studies with more than 900 patients and convincingly demonstrated that stentless AVR does offer a lower valve pressure gradient and more rapid LV mass regression at 6 months than stented AVR, (at the expense of a longer aortic cross-clamp time). A meaningful clinical comparison of the hemodynamic performance between stentless and stented AVR is based on the assumption that both achieve an in vivo effective orifice area (EOA) inline with in vitro measurements. However, the in vivo EOA for stentless AVR was often only 60% of its in vitro measurement. The corresponding figure for stented AVR was greater than 90% [2Dumesnil J.G. LeBlanc M.H. Cartier P.C. et al.Hemodynamic features of the Freestyle aortic bioprosthesis compared with stented bioprosthesis.Ann Thorac Surg. 1998; 66: S130-S133Abstract Full Text Full Text PDF PubMed Scopus (71) Google Scholar]. The stentless EOA discrepancy is mainly due to requiring a semi-reconstructive procedure. When the implantation is well optimized in the native aortic root, the stentless valve EOA can be as much as 90% of in vitro EOA [3Jin X.Y. Dhital K. Bhattacharya K. et al.Fifth-year hemodynamic performance of the Prima stentless aortic valve.Ann Thorac Surg. 1998; 66: 805-809Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar]. Therefore the significant, but modest, in vivo hemodynamic advantage of the stentless AVR demonstrated in Kunadian and colleagues’ [1Kunadian B. Vijayalakshmi K. Thornley A.R. et al.Meta-analysis of valve hemodynamics and left ventricular mass regression for stentless versus stented aortic valves.Ann Thorac Surg. 2007; 84: 73-79Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar] meta-analysis was achieved despite the in vivo under performance of the stentless valve against its stented competitor. If the stentless AVR clinical trials necessitated the recruitment of less experienced surgeons to boost implant numbers, their findings may reflect the performance of the surgeon rather than that of the stentless prosthesis. The changes in LV mass index after stentles and stented AVR is an important comparative physiological end point, but this approach requires significant pre-existing and reversible LV hypertrophy (LVH) caused by aortic valve disease, and it requires the absence of confounding diseases that cause LVH. As the majority of LVH regression takes place in the first 6 months after surgery, the favorable effects of stentless AVR should be evident at this time point. This indeed was the case in this meta-analysis. Beyond 6 months hypertension, atrial fibrillation, cardiac dysfunction, and associated medical treatments will play an increasing role in determining residual LVH [4Jin X.Y. Pillai R. Westaby S. Medium-term determinants of left ventricular mass index after stentless aortic valve replacement.Ann Thorac Surg. 1999; 67: 411-416Abstract Full Text Full Text PDF PubMed Scopus (35) Google Scholar], and these factors probably explain the long-term survival advantage of stentless AVR being more evident in patients younger than 70 years of age in comparison with those older than 70 years [5Del Rizzo D.F. Abdoh A. Cartier P. et al.The effects of prosthetic valve type on survival after aortic valve surgery.Semin Thorac Cardiovasc Surg. 1999; 11: 1-8PubMed Google Scholar]. Given the impact of surgeon’s expertise on stentless valve hemodynamics and of the patient’s factors on LVH regression after AVR, the individual randomized clinical trial in elderly AVR patients requires more thoughtful interpretation. To this end, the current meta-analysis has offered an important complementary approach. Its findings should be commended for the further development of both surgical expertise and user-friendly prosthesis for the stentless AVR. Meta-Analysis of Valve Hemodynamics and Left Ventricular Mass Regression for Stentless Versus Stented Aortic ValvesThe Annals of Thoracic SurgeryVol. 84Issue 1PreviewStentless aortic bioprostheses have been advocated as being superior to conventional bioprosthetic valves, with benefits including superior left ventricular mass regression and larger effective orifice area. Several high-quality randomized studies now exist on this topic, and we sought to summarize them by meta-analysis. Full-Text PDF

Perforation of the Valsalva Sinus After Implantation of Medtronic Freestyle Aortic Bioprosthesis

We report on structural valve deterioration in patients with the Medtronic Freestyle aortic bioprosthesis (Medtronic, Inc, Minneapolis, MN), including spontaneous perforation of the Valsalva sinus. These occurred in four prosthesis in 3 patients using the modified subcoronary method or full root technique. One patient died of ruptured pseudoaneurysm and the others survived reoperation well. Careful follow-up is required after Freestyle bioprosthesis implantation.

Infectious false aneurysm of the right ventricular outflow tract after repair of congenital heart defect treated with Freestyle aortic bioprosthesis

False aneurysm of the right ventricular outflow tract (RVOT) is one of complications after surgery of congenital heart disease. It is controversial about materials for reconstruction of RVOT in this setting, when associated with pulmonary hypertension or bacterial infection. Pulmonary homograft seems to be the first choice, but its availability is extremely limited in Japan. Therefore, we used Freestyle stentless bioprosthesis to reconstruct the RVOT in a 14-year-old boy who developed infectious false aneurysm of RVOT after total correction of pulmonary atresia with ventricular septal defect. After describing the patient, the prosthesis alternative to the pulmonary homograft was discussed.

Early experience of aortic valve replacement with the Freestyle stentless aortic bioprosthesis in elderly patients.

Stentless bioprostheses have been gaining popularity in recent years as hemodynamically superior alternatives to conventional stented bioprostheses. Between July 1996 and November 1998, 13 patients with aortic valve disease, 7 males and 6 females with a mean age (+/- SD) of 68 +/- 5 years, underwent an aortic valve replacement using the Medtronic Freestyle aortic bioprosthesis. The predominant lesions were stenosis in 8 patients and regurgitation in 5, while 2 patients had endocarditis. The operation was performed by a subcoronary technique in 9, root-inclusion technique in 3, and full root technique in 1 patient. Throughout the follow-up periods (with average follow-up period of 20.6 months), there was no hospital mortality, though there was one late death of unknown cause. The New York Heart Association class improved in all patients. The peak transvalvular gradient decreased from 18.4 +/- 9.8 to 12.6 +/- 9.6 mmHg, and the effective valve orifice area increased from 2.30 +/- 0.96 to 2.59 +/- 1.05 cm2 between the 1-month and the 6-month follow-up examinations. In patients with aortic regurgitation, the left ventricular end-diastolic/end-systolic volume index significantly decreased from 147 +/- 36/62 +/- 19 to 73 +/- 26/33 +/- 14 ml/m2 at 1 month after the operation. The left ventricular mass index also significantly decreased from 189 +/- 26 to 143 +/- 30 g/m2 in patients with aortic regurgitation and from 171 +/- 28 to 144 +/- 30 g/m2 in those with aortic stenosis. Although long-term follow-up is required for further evaluation, the early results appeared to indicate that the Freestyle aortic bioprosthesis was suitable for elderly patients requiring aortic valve replacement.

Stentless bioprostheses have ideal haemodynamics, even in the small aortic root.

To determine normal Doppler and 2D gradients and flow characteristics of the Freestyle stentless aortic bioprosthesis related to valve size. The Freestyle stentless aortic bioprosthesis is one of the newer aortic xenografts. Only limited data are available of the echocardiographic flow characteristics during a mid-term follow-up period of this valve. Therefore valve performance related to valve size was measured during a follow-up period of two years. 175 consecutive patients with a Freestyle aortic bioprosthesis underwent an echocardiographic and Doppler examination according to a common protocol. Investigations were done within 4 weeks after operation, after 3 to 6 months, and after 1 and 2 years. With a valve size from 19 to 27 mm mean gradients decreased from 8.0 +/- 5.1 mmHg at discharge to 5.8 +/- 3.8 mmHg after 3-6 months (p < 0.001). Thereafter gradients remained stable. The performance index, the ratio of the measured effective orifice area in the patient divided by the effective orifice area measured in vitro increased from 69 +/- 20% at discharge to 79 +/- 29% after one, two and three years. Performance index was especially very high in the smaller sized valves with a performance index of 85 +/- 17% for the 21 mm valve. During follow-up mean gradients remained below 10 mmHg even in the 21 mm valve. Stentless xenografts have ideal haemodynamics, even in the small aortic root.

Echocardiographic Parameters of the Freestyle Stentless Bioprosthesis in Aortic Position: The European Experience

The objective of this study was to determine normal Doppler and 2-dimensional characteristics of the Freestyle stentless aortic bioprosthesis. The Freestyle aortic bioprosthesis is a new type of aortic xenograft, and experience is limited. We therefore determined the normal range of echocardiographic and Doppler examinations of this valve. Three hundred thirty-nine consecutive patients with a Freestyle aortic bioprosthesis underwent an echocardiographic and Doppler examination according to a common protocol. Investigations were done within 4 weeks after operation, after 3 to 6 months, and after 1, 2, and 3 years. With a valve size from 19 to 27 mm, mean gradients decreased from 7.9 ± 5.1 mm Hg at discharge to 5.5 ± 3.8 mm Hg after 3 to 6 months ( P < .001). Thereafter, gradients remained stable. Effective orifice area 1 year after implantation was 1.59 ± 0.58 cm 2 for the 21-mm valves, 1.92 ± 0.74 cm 2 for the 23-mm valves, 2.03 ± 0.64 cm 2 for the 25-mm valves, and 2.52 ± 0.72 cm 2 for the 27-mm valves ( P < .001). The performance index, the ratio of the measured effective orifice area in the patient divided by the effective orifice area measured in vitro, increased from 67% ± 20% at discharge to 82% ± 29% after 1, 2, and 3 years. Performance index was especially very high in the smaller-sized valves. After implantation with the subcoronary technique or root-inclusion technique, small cavities could be seen between the native aortic root and the Freestyle valve. Doppler values were evaluated for the Freestyle stentless porcine bioprostheses in the aortic root. Gradients appear to be close to those measured in native valves over a time period of 3 years. (J Am Soc Echocardiogr 1999;12:729-35.)

Hemodynamic features of the freestyle aortic bioprosthesis compared with stented bioprosthesis

Background. The Freestyle prosthesis is a new stentless aortic bioprosthesis. Anticipated benefits are improved hemodynamics and increased longevity. Methods. Doppler echocardiograms were performed early and at 3 to 6 months, 1 year, and 2 years after operation in 157 patients (69 men, 88 women, aged 48 to 85 years) with this prosthesis, and results were compared with hemodynamic data in patients with Intact and Mosaic stented bioprostheses. Results. Distinctive features of the prosthesis compared with stented prostheses are (1) an increase in effective orifice area (+0.15 ± 0.26 cm 2; p < 0.05) and a decrease in mean gradient (−3.5 ± 4.0 mm Hg; p < 0.001) during the first 3 to 6 months postoperatively and stabilization thereafter; (2) a markedly lower mean gradient at 1 year after operation (average, 6 ± 4 mm Hg) than in stented prostheses (Intact, 22 ± 8 mm Hg; Mosaic, 12 ± 6 mm Hg); (3) in contrast to stented prostheses, in vivo effective orifice areas much lower (−0.91 ± 0.35 cm 2) than those calculated in vitro; (4) as in stented prostheses, the indexed effective orifice area (cm 2/m 2) is the best predictor (r = 0.77 at 1 year) of the mean gradient after operation; and (5) similar incidence of aortic regurgitation (trivial or mild, 34% versus 29% in Intact). Conclusions. The hemodynamics of the Freestyle are very satisfactory and represent a marked improvement in comparison to stented prosthesis.