Stentless Aortic Valve Replacement Research Articles

Stentless valves for bicuspid and tricuspid aortic valve disease

ObjectiveTo determine long-term survival and reoperation rate in patients with a bicuspid aortic valve (BAV) and patients with a tricuspid aortic valve (TAV) after stentless aortic valve replacement (AVR)/aortic root replacement (ARR). MethodsBetween 1992 and 2014, 1293 patients underwent first AVR/ARR with a stentless aortic valve using the modified inclusion operating technique, including 741 patients with a TAV and 552 with a BAV. Using propensity scoring with 26 variables, 330 matched pairs were identified with AVR with or without ascending aorta/arch replacement. Data were obtained through chart review, surveys, and the National Death Index. ResultsPatient demographics were similar in the propensity score–matched groups. Both groups had similar cardiopulmonary bypass, cross-clamp, and hypothermia circulatory arrest times, cerebral protection strategies, and rate of aortic arch replacement. The median size of implanted valves was similar (BAV: 27 mm [range, 25-29 mm] vs TAV: 27 mm [range, 25-27 mm]). Compared with the TAV group, the BAV group had a shorter hospital stay (6 days vs 7 days; P = .001) but similar 30-day mortality (1.8% vs 1.2%). The BAV group had better long-term (15-year) survival (46% vs 33%; P = .002) but a higher cumulative incidence of reoperation for structural valve deterioration (15-year: 15% vs 11%; P = .048). Cox proportional hazard analysis identified a BAV as a protective factor for long-term mortality (hazard ratio [HR], 0.71; 95% CI, 0.56-0.91; P = .006), but a risk factor for reoperation due to structural valve deterioration (HR, 1.4 [95% CI, 0.8-2.6; P = .27] in the matched cohort and 2.2 [95% CI, 1.3-3.7; P = .004] in the unmatched cohort). ConclusionsThe BAV patients had better long-term survival but a higher reoperation rate compared with TAV patients after stentless AVR. Our findings suggest caution in the use of bioprostheses for BAV patients.

Propensity matched long-term analysis of mechanical versus stentless aortic valve replacement in the younger patient.

The choice of prosthesis for aortic valve replacement (AVR) in younger patients remains controversial. Stentless AVR was introduced 3 decades ago, with the aim of better haemodynamics and durability than stented xenografts. The objective of this analysis was to compare the long-term outcomes to mechanical prostheses in younger patients (age ≤60 years). All adult patients who underwent AVR due to aortic valve stenosis and/or insufficiency between 1993 and 2002 were identified. After the exclusion of patients with congenital heart defects, aortic dissections and Ross-procedures, 158 patients with stentless valves and 226 patients with bi-leaflet mechanical valves were finally included in this analysis. Sixty-six patient pairs could be included in a propensity matched analysis. Mortality and morbidity including stroke, bleeding, endocarditis and reoperation were analysed. Group baseline characteristics and operative data did not differ significantly after propensity matching. Hospital mortality was 0.0% in the stentless and 1.5% in the mechanical group. Total patient years/median follow-up was 2029.1/15.4 years (completeness: 100.0%, range: 0-25 years). After 20 years, actuarial survival was 47.0 ± 6.4% in the stentless and 53.3 ± 6.6% in mechanical group (P = 0.69). Bleeding, endocarditis and stroke occurred rarely and did not differ significantly between groups. After 20 years, actuarial overall freedom-from-reoperation was 45.1 ± 8.2% in the stentless group and 90.4 ± 4.1% in the mechanical group (P < 0.001). Hospital mortality while reoperation was 7.4% in the stentless group and 0% in the mechanical group (P = 1.0). Long-term morbidity and mortality of stentless and mechanical aortic valves were statistically not different besides a significantly higher reoperation rate after stentless AVR combined with a probably higher risk of in-hospital mortality. Thus, mechanical AVR should remain the procedure of choice in younger patients.

Invited Commentary

Invited Commentary

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.

Successful Stentless Aortic Valve Replacement Navigated by VR Images in a Case of Bicuspid Aortic Stenosis with Valsalva Sinus Asymmetry

Successful Stentless Aortic Valve Replacement Navigated by VR Images in a Case of Bicuspid Aortic Stenosis with Valsalva Sinus Asymmetry

Stented Versus Stentless Aortic Valve Replacement in Patients With Small Aortic Root: A Systematic Review and Meta-Analysis.

The aim of the study was to compare hemodynamic and perioperative outcomes of stented against stentless aortic valve replacement in patients with small aortic root (21 mm or less). A comprehensive search was undertaken among the four major databases (PubMed, Embase, Scopus, and Ovid) to identify all randomized and nonrandomized controlled trials comparing stentless to stented bioprosthetic valves in small aortic root patients. Odds ratios, weighted mean differences, or standardized mean differences and their 95% confidence intervals were analyzed. A total of seven studies with a total of 965 patients fulfilled the inclusion criteria. There was no significant difference in preoperative baselines including mean age between both groups (P = 0.08), peak aortic valve gradient (P = 0.06), and effective orifice area (P = 0.28), whereas higher mean aortic valve gradient in the stented group (P = 0.007). No difference in cardiopulmonary bypass time (P = 0.74), aortic cross-clamp times (P = 0.88), intensive care unit stay (P = 0.13), and stroke rate (P = 0.56) were noted. However, stented group of patients showed higher rate of patient prosthesis mismatch (P = 0.0001) and longer total hospital stay (P = 0.002). Postoperatively, stentless group showed lower peak and mean aortic valve gradient (P = 0.003 and P = 0.008, respectively) with a better effective orifice area (P < 0.00001) at 6 months of follow-up. Mortality rates while in-hospital and at 1 year were similar in both groups (P = 0.94 and P = 0.86, respectively). Stentless aortic valves offer superior short-term hemodynamic outcomes in patients with small aortic root when compared with stented aortic valves. Although both groups have similar perioperative complications rates, stentless valves bring about a shorter hospital stay. A further large multicenter randomized controlled trial should address the longer-term benefit of stentless aortic valve over stented valve.

Stented versus stentless aortic valve replacement in elderly: a systematic review and meta-analysis

Background: Stentless aortic bioprostheses offer improved outcomes and long-term survival over stented aortic bioprostheses in aortic valve replacement (AVR). However, it remains unclear whether this improved outcome can also be demonstrated in elderly patients. This meta-analysis sought to determine whether stentless bioprosthetic valves improve clinical outcomes compared with stented valves in elderly patients undergoing AVR. Methods: A comprehensive search was undertaken among PubMed, Embase, Scopus, and Ovid to identify all randomized and nonrandomized controlled trials available up to March 2017 comparing stentless to stented bioprosthetic valves in elderly patients undergoing AVR. Odds ratios (ORs), weighted mean differences, or standardized mean differences and their 95% confidence intervals (CIs) were analysed. Results: A total of 1,048 patients were analysed and data extracted from six studies were suitable for meta-analysis. Average age was 77 years. The stented group displayed a significantly shorter cardiopulmonary bypass (P&lt;0.0001; 95% CI: 0.424 to 1.05) and aortic cross clamp time (P&lt;0.0001; 95% CI: 0.237 to 0.491) compared to the stentless group. There was no difference in the relative risks of stroke events (P=0.5074). In hospital mortality was significantly lower in the stentless group (P&lt;0.0001). However, there was no difference in the 5-year mortality postoperatively for the two groups (P=0.835). Conclusions: Our results showed that stentless aortic valves resulted in lower in-hospital and similar 5-year mortality compared to stented valves, despite less favourable operative data. They have also had better echocardiographic findings both while in hospital and at 6 months of follow up.

Stented vs Stentless aortic valve replacement in patients with small aortic root: A systematic review and meta-analysis

Stented vs Stentless aortic valve replacement in patients with small aortic root: A systematic review and meta-analysis

Aortic valve replacement using the Freedom SOLO stentless bioprosthesis: clinical and haemodynamic performance in 625 patients at medium-term follow-up.

Our goal was to analyse the haemodynamic and clinical results after implantation of the Freedom SOLO stentless aortic valve replacement by assessing the immediate postoperative results regarding mortality, discharge echocardiographic gradients and reoperation rates and by evaluating these results in the medium term. This study was designed as a single-centre retrospective observational trial. Clinical and echocardiographic data were collected retrospectively from 625 patients undergoing an aortic valve replacement using the Freedom Solo stentless valve (LivaNova, London, UK) at the Sint-Jan Hospital, Bruges, between May 2009 and May 2017. The mean age of the patient was 76 ± 6.9 years. Early operative (30-day) mortality was 3.5% overall and 0.8% (n = 2) in patients having isolated aortic valve replacement. Early reinterventions were necessary in 3% of patients (n = 19). Permanent pacemaker implantation was performed in 3%. The mean postoperative peak gradient was 14.3 ± 8.14 mmHg, and the mean gradient was 7.5 ± 4.46 mmHg. Fourteen patients underwent explantation, 2 of which were for structural valve deterioration and 8 for endocarditis. Overall survival at 7 years was 55% [95% confidence interval (CI) 47-62]. At 7 years, freedom from reoperation overall, freedom from operation for endocarditis and freedom from operation for structural valve deterioration were 94% (95% CI 88-97), 97% (95% CI 94-99) and 98% (95% CI 90-99), respectively. The Freedom Solo stentless aortic valve has proved to be safe, with excellent clinical and haemodynamic results. Structural valve degeneration and explantation occur infrequently, illustrating good durability in the medium term.

Aortic valve replacement using autologous pericardium: single centre experience with the Ozaki technique.

To assess the clinical implementation and report preliminary results of a novel technique called the Ozaki procedure for stentless aortic valve replacement through reconstruction of the valve leaflets from autologous pericardium. Between September 2015 and May 2017 30 patients (20 males, mean ± standard deviation age 66.83 ± 10.55 years) suffering from aortic stenosis (AS, n = 7), aortic regurgitation (AR, n = 12), or a combination of both (AS/AR, n = 11) were assigned for an Ozaki procedure. The glutaraldehyde-treated autologous pericardium was intraoperatively customised and tailored according to individual sinus measurements and appropriate Ozaki templates (CE marked). Mean and peak preoperative transvalvular pressure gradients in patients with AS were 46.34 ± 14.71 and 78.00 ± 22.54 mm Hg, respectively and effective orifice area was 0.93 ± 0.26 cm2. Ejection fraction was preserved at 57.37 ± 10.33%. Twenty-four valves were tricuspid and 6 bicuspid; 13 patients had concomitant cardiac surgery (coronary artery bypass graft, mitral valve repair, replacement of ascending aorta). Mean ± SD cross-clamp time for replacement only was 85.18 ± 18.10 minutes and perfusion time 104.76 ± 38.52 minutes. Cusp sizes were 27.76 ± 3.52 mm for the left coronary cusp (CC), 28.20 ± 3.51 mm for the right CC and 29.20 ± 3.34 mm for non-CC. Mean and peak postoperative gradients decreased to 8 ± 3.55 and 14.8 ± 6.21 mm Hg, respectively. Mean length of stay on the intensive care unit was 2.19 ± 2.34 days and in-hospital stay was 8.81 ± 2.04 days after isolated Ozaki procedures. No pacemaker had to be implanted after an isolated Ozaki procedure. Thirty-day mortality was 3.33% (n = 1). After 3 months, no patient presented with aortic stenosis, and regurgitation of the substituted valves was graded nil/trace in 85.71%, mild in 10.71%, and moderate in 3.57% of the patients. Ejection fraction remained unchanged at 58.89 ± 11.29%. No reoperation was required within the first 3 months. This aortic valve replacement technique has become available only recently. In our experience, it can be mastered after a relatively short training period, and has become part of our routine clinical toolbox. The use of autologous pericardium in combination with excellent haemodynamics may have the potential to overcome the structural disadvantages of biological aortic valves, to be beneficial in infective endocarditis, and to represent an alternative for patients with small annuli.

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.

Truly stentless xenopericardial aortic valve replacement as an alternative to standard aortic valve replacements

&lt;p&gt;&lt;strong&gt;Aim:&lt;/strong&gt; The study was to determine the feasibility and safety of truly stentless aortic valve replacement with bovine pericardium sutured directly onto the aortic wall by using a holding device.&lt;br /&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Seven patients with pronounced aortic stenosis and coronary artery disease who underwent aortic valve leaflets plasty with a xenopericardial patch by means of a holding device combined with CABG were recruited. &lt;br /&gt;&lt;strong&gt;Results:&lt;/strong&gt; The aortic valve was successfully re-paired in 7 patients. A normal function of the valve was confirmed by echocardiographic data obtained in all patients. No complications were observed during follow-up. Mean hospital stay was 17 (13; 35) days. No reoperation for the aortic valve was performed during follow-up. Hospital mortality was 0%. Mean follow-up was 759 days. Long-term survival rate was 86%. Freedom from structural valve deterioration, thromboembolism, endocarditis and reoperation ran to 100%. The peak gradient across the aortic valve in the late period was 30 (26; 42) mm Hg, peak speed amounted to 3 (2.8; 3.2), mean aortic regurgitation grade was 1±0.1 degree.&lt;br /&gt;&lt;strong&gt;Conclusion:&lt;/strong&gt; Truly stentless xenopericardial aortic valve replacement is a good alternative to standard aortic valve replacement. This method is safe with regard to freedom from reoperations, degenerative valve changes, thromboembolism, endocarditis in the early and late postoperative periods.&lt;/p&gt;

Advances in training: A high fidelity practical course on cadavers for complex cardiac procedures

s / International Journal of Surgery 12 (2014) S13eS117 S76 0313: ADVANCES IN TRAINING: A HIGH FIDELITY PRACTICAL COURSE ON CADAVERS FOR COMPLEX CARDIAC PROCEDURES John Massey, Jasmine Winter-Beatty , Nigel Drury, Jitendra Parmar. University Hospital Coventry and Warwickshire, Coventry, UK. Introduction: Surgical education is changing owing to implementation of European Working time Directive. Cadaveric-based educational programs have had positive feedback from surgical trainees. Our training centre allows trainees to gain experience in complex cardiac procedures in a safe, non-time pressurised environment.We look at how trainees benefit from a high fidelity course-training surgeons to perform two complex cardiac procedures. Methods: Cadavers had been prepared through a midline sternotomy, pericardium opened with heart and great vessels exposed. Trainees performed a stentless aortic valve replacement and an aortic root replacement. Faculty surgeons facilitated learning as required. Results: There was a 100% response for a post course feedback form. Knowledge survey revealed an increase in perception of knowledge. There was an increase in trainees' confidence to assist these procedures in future. 100% of attendees would recommend it to their peers. Trainees stated that they felt more comfortable assisting and performing the procedures having practiced on cadavers. Conclusions: Simulated training using fresh frozen human cadavers can be incorporated into surgical training of cardiothoracic trainees. Such a course can have high face validity and significantly improve trainees' perception of technical knowledge as well as increasing confidence to assist and perform complex cardiac procedures. 0320: THE LESSER-SPOTTED MEDICAL STUDENT: UNDERSTANDING AND FACILITATING STUDENT PRESENCE ON WARDS Ian Henderson, Jessika Voll , Damian Bragg. Queen's Medical Centre (NUH),

THE CLINICAL OUTCOME AFTER AORTIC VALVE REPLACEMENT WITH FREEDOM SOLO STENTLESS BIOPROSTHESIS IN NORTH AMERICA - A SINGLE CENTER EXPERIENCE

The Freedom SOLO stentless bioprosthesis has been widely used in Europe as an option for stentless aortic valve replacement. In North America however, this valve has not been broadly used. We are reporting the first short and midterm clinical outcomes of aortic valve replacement(AVR) with Freedom SOLO stentless bioprosthesis in a single North American center. This is a retrospective study using the existing database and patients charts at the University of Alberta Hospital and Mazankowski Alberta Heart Institute. From February 2011 to October 2013, 189 consecutive patients 126(66.7%) male with a mean age of 71.8±10.4 years (19-90 years) underwent aortic valve replacement with the Freedom SOLO stentless bioprosthesis. All patients were included in this study, 39 patients had isolated AVR and 150 had combined procedures. Univariate and multivariate analysis were performed and significant values (p<0.05) were reported. All patients had a pre-operative and at least one postoperative echo study done. The 30 day post-operative mortality for isolated AVR and combined procedures were 0%(n=0) and 4.2%(n=8) respectively. There was no structural valve degeneration or perivalvular leaks during the entire follow up period, however mild central aortic regurgitation was found in 5(3%) patients. Mean cross-clamp time for isolated aortic valve replacement and combined procedures were 78.3±17.8min and 91.5±16.6 min respectively. The mean cardiopulmonary bypass time for isolated AVR and combined procedures were 127.2±43.2 min and 163.5±50.3 min respectively. Echocardiographic results in the immediate postoperative period showed a significant decrease in mean and peak transvalvular gradients. The mean gradient decreased from 39.4±17.5mmHg to 8.2±4.9mmHg and peak gradient decreased from 67.9±30.0mmHg to 16.7±9.7mmHg. The postoperative effective orifice area(EOA) increased from 0.87 to 1.94cm2 and the effective orifice area index (EOAi) increased from 0.45 to 1.00 cm2/m2 which were also significant. There was a significant LV mass regression (215.4 to 178.6g) that took place within six months postoperatively. Left ventricular ejection fraction was unchanged during the course of this study. At 30 days follow-up, ten patients (5.3%) had complete heart block requiring permanent pacemaker insertion. Our experience shows that the Freedom SOLO bioprosthesis has an overall good short and midterm clinical and hemodynamic outcomes.

Use of balloon expandable transcatheter valves for valve-in-valve implantation in patients with degenerative stentless aortic bioprostheses: Technical considerations and results

Transcatheter valve-in-valve is an accepted treatment in high-risk patients with degenerative stented bioprostheses in the aortic position. Experience in treating stentless valves is, however, limited. Our aim was to determine the feasibility and single-center outcome of balloon expandable SAPIEN valve placement in degenerated stentless aortic valve bioprostheses. From February 2010 to January 2014, 10 patients with failing stentless bioprostheses underwent transcatheter aortic valve implantation using the Edwards SAPIEN transcatheter heart valve (SAPIEN, SAPIEN XT, and SAPIEN 3) at our institution. Seven patients had valve failure due to regurgitation and three to stenosis. The mean age was 73.3 ± 15.0 years. The mean logistic EuroSCORE was 31.8 ± 20.3, and the Society of Thoracic Surgeons score was 7.6 ± 5.4. Technical success was achieved in 9 of 10 patients. One patient required immediate placement of a second valve owing to low placement of the first. Two intraoperative complications developed that needed additional procedures. One patient underwent immediate repair of a right ventricular perforation from a pacing lead, the other, reexploration for epicardial bleeding. No deaths occurred. The median length of stay was 8.5 days (range, 3-44). The mean follow-up was 8.1 months (range, 1-21). No late reoperations or reinterventions were required. Transcatheter aortic valve implantation after previous stentless aortic valve replacement is technically demanding but a safe and feasible approach. The early results were excellent, with consistent improvement in hemodynamics. Prospective long-term follow-up in larger series is needed to evaluate this technique further.

Hemodynamic performance and outcome of percutaneous versus surgical stentless bioprostheses for aortic stenosis with anticipated patient–prosthesis mismatch

We aimed to compare the performance and midterm survival of transcutaneous aortic valve replacement (TAVR) and surgically implanted stentless aortic valve replacement (SAVR) for severe aortic stenosis in patients anticipated to have patient-prosthesis mismatch (PPM). A retrospective analysis was performed of 86 and 49 consecutive TAVR and SAVR patients with severe aortic stenosis and calculated minimal effective orifice area larger than the best projected effective orifice area. Cox hazard analyses were used to assess the effect of TAVR versus SAVR on outcome. The peak and mean transprosthetic gradient at discharge were lower (P < .001 for both) in the TAVR group. Mild or greater aortic regurgitation was more frequent in the TAVR group (61% vs 7%; P < .0001). At 3 months of follow-up, the mean gradient in the TAVR group was similar to that of the SAVR group but the prevalence of aortic regurgitation was still higher. The unadjusted 3-year survival rate was superior in the SAVR versus TAVR group (91.6% ± 4% vs 67.0% ± 7%; P = .01). Adjustments for both age and comorbidity resulted in loss of the difference in mortality between the 2 groups. In patients with anticipated PPM, TAVR offers an immediate lower incidence of PPM than SAVR but a greater prevalence of aortic regurgitation. The differences in transaortic gradients became nonsignificant 3 months postoperatively. The question of whether TAVR is a suitable substitute for SAVR in patients with anticipated PPM, in particular, those who are older and sicker, warrants additional investigation.

A parametric study on mathematical formulation and geometrical construction of a stentless aortic heart valve

This study presents a novel methodology for constructing an accurate geometrical model of a stentless aortic heart valve replacement (AVR). The main objective is to propose an optimized AVR model that can be used as an ideal scaffold for tissue engineering applications or a biocompatible prosthesis. Current techniques available for creating heart valve geometry, including leaflets, are very complicated and are not precise, due to the extensive use of various complicated parameters. This paper introduces an alternative design procedure that uses limited and effective numbers of controlling parameters to construct the whole valve including the sinus of valsalva. In doing so the hyperbolic curves for multithickness leaflets are used and a 3D elliptical formulation is incorporated for the surface geometry of the sinus of valsalva. Still, the feasibility and the precision of the mathematical method are established by performing standard deviation analysis on the constructed surfaces. The surface fitting residuals are found as low as error 0.2351mm with standard deviation of 8.83e-5 over the commissural lines. Preliminary validation to the proposed AVR model performance is achieved by testing the generated AVR model under quasi static condition while obtaining the mesh independent setup. The numerical model showed a rapid response of the leaflets to the transvalvular pressure where adequate values of stress are measured over the commissural lines.

Stentless aortic valve replacement in the young patient: long-term results

BackgroundStentless aortic valve replacement (SAVR) became a common surgical procedure to treat aortic valve disease, as it offers larger orifice area and improved hemodynamics. The aim of our single-centre retrospective study was to assess long term results of first generation stentless aortic valves in young patients, where mechanical prostheses are considered first line therapy.MethodsFrom 1993 to 2001, 188 (149 male and 39 female) patients (≤60 years) underwent SAVR. Indications were in 63.3% stenosis or mixed lesions and in 36.7% isolated regurgitation. Mean age of patients at surgery was 53.1 ± 7.1 years. Associated procedures were performed in 60 patients (31.9%). Follow-up data were acquired through telephone interviews. Follow-up was 90.4% complete at a mean of 8.8 ± 4.7 years. Total follow-up was 1657.6 patient-years with a maximum of 17 years.ResultsOverall hospital mortality was 3.2% (2.5% for isolated SAVR). Overall actuarial survival-rate at 10/15 years and freedom from reoperation at 10/14 years were 73.0% ± 3.5%/ 55.8% ± 5.4% and 81.0% ± 3.4%/ 58.0% ± 7.5%, respectively. For isolated SAVR, actuarial survival at 10/15 years and freedom from reoperation at 10/14 years were 70.1% ± 4.4%/ 64.1% ± 4.8% and 83.1% ± 4.0%/ 52.9% ± 9.0%, respectively. Reoperation was performed in 42 patients (22.3%) due to structural valve deterioration and endocarditis. Age (≤50 years) and associated procedures did not significantly lower survival and freedom from reoperation, however, small prosthesis sizes (≤25 mm) did.ConclusionIn patients aged 60 and younger, SAVR provides reliable long-term results especially for larger aortic valves.

Transesophageal Echocardiographic Imaging of Aortic Valve Replacement Using Autologous Glutaraldehyde-Treated Pericardium

Transesophageal Echocardiographic Imaging of Aortic Valve Replacement Using Autologous Glutaraldehyde-Treated Pericardium

Failing stentless aortic valves: redo aortic root replacement or valve in a valve?

Reoperation for failing stentless aortic valve replacement is a technically demanding procedure that has traditionally been tackled in one of two ways: either root replacement or the more conservative option of implanting a stented valve within the valve. We sought to determine the relative operative risks, follow-up status and medium to long-term survival of these two methods. We conducted a retrospective review of a single surgeon's experience of the two techniques over a 10-year period from 2000 to 2010. Excluding cases of active endocarditis, 110 patients were identified, of which 65 underwent 'valve-in-valve' procedures ('Group A') and 45 had redo root replacement ('Group B'). The most common bioprostheses reoperated were homografts (roots or subcoronary implants) and Toronto Stentless Porcine Valves. Aortic valve replacement alone was performed in 68% in Group A and 64% in Group B, with males comprising 75% of Group A and 82% of Group B. Average ages were 61.5 ± 14.2 years and 61.9 ± 12.1 years, respectively. Operative and cardiopulmonary bypass durations were significantly greater for redo root procedures and correspondingly, postoperative complications were more common. Thirty-day mortality after valve-in-valve replacement was 3%, and after redo root replacement it was 11%. Despite significantly higher transvalvular gradients in Group B, the symptomatic status was equally good at 2 months, 1 year and last follow-up. At an average interval of 5.1 ± 2.7 years for Group A, survival was 83% vs 76% at 7.3 ± 2.9 years for Group B. There have been two reinterventions in Group A and 3 in Group B. Only one valve-in-valve patient has developed a paraprosthetic leak. This retrospective review has confirmed our hypothesis that where both root diameter permits and satisfactory debridement can be performed, valve-in-valve replacement is the more conservative surgical strategy for stentless aortic valve replacement revision. Although transvalvular gradients on echocardiography are significantly higher with the introduction of a stented prosthesis, medium-term outcomes in terms of symptomatic status, late complications and reintervention rate were non-inferior. We await the medium-term results of transcatheter aortic valve implantation for the same indication with interest.