The impact of socio-demographic factors on health-related quality of life after coronary artery bypass surgery.

OBJECTIVES: To achieve a beneficial impact on long-term outcome after coronary artery bypass grafting (CABG), the goal of the present study was the early identification of patients at risk of impaired postoperative health-related quality of life (HRQoL), particularly evaluating the significance of socio-demographic variables. METHODS: In this prospective, single-centre cohort study of patients having an isolated CABG (January 2004-December 2014), preoperative socio-demographic (preSOC) and preoperative medical variables as well as 6-month follow-up data including the Nottingham Health Profile were analysed in 3,237 patients. RESULTS: All preSOC (gender, age, marriage and employment) and follow-up (chest pain, dyspnoea) variables proved to have significant influence on HRQoL (P < 0.001), male patients below 60 years being particularly impaired. The effects of marriage and employment on HRQoL are modulated by age and gender. The significance of the predictors of reduced HRQoL differs between the 6 Nottingham Health Profile domains. Multivariable regression analyses revealed explained proportions of variance amounting to 7% for preSOC and 4% for preoperative medical variables. CONCLUSIONS: The identification of patients at risk of impaired postoperative HRQoL is decisive for providing additional support. This study reveals that the assessment of 4 preoperative socio-demographic characteristics (age, gender, marriage, employment) is more predictive of HRQoL after CABG than are multiple medical variables.

Conventional cardiac surgery in patients with end-stage coronary artery disease: yesterday and today.

Surgical therapy of combined coronary artery disease (CAD) and heart failure, also referred to as end-stage CAD, has evolved throughout the years and patients are currently being offered traditional coronary artery bypass grafting (CABG), with or without surgical ventricle restoration (SVR), interventions for ischemic mitral valve regurgitation, heart transplantation or implantation of mechanical cardiovascular support systems. Among surgical methods, operative myocardial revascularization (with or without ventricle restoration) is still playing an important role, aiming at restoration of proper myocardial perfusion, especially if heart muscle viability is present. Facing the donor shortage, CABG may constitute a valuable alternative to transplantation in selected patients. In individuals considered not suitable for surgical revascularization, implantation of mechanical circulatory support (MCS) not only appears as a salvage procedure, but also allows for reevaluation of future therapy directions. This article aims at providing an overview of evolving and current surgical practices in patients with end-stage CAD.

Health-related quality of life after heart surgery - Identification of high-risk patients: A cohort study.

BACKGROUND: This cohort study evaluated factors, which have been shown to be relevant for Health-Related Quality of Live (HRQL) after cardiac surgery and investigated the combinatory impact on HRQL. Additionally, the aim was to introduce a first attempt to developing a risk estimation model which could identify patients at risk for impaired HRQL. METHODS: For this single-centre cohort study, 6099 cardiac surgical patients (60% isolated coronary bypass surgery) filled in the Nottingham Health Profile (NHP) for the evaluation of HRQL six months after surgery and provided information regarding their medical and socio-demographic status. For the NHP scores the deviation to the matched normative data of a healthy sample was calculated. A robust linear regression examined factors that influence HRQL. As a next step, based on the regression model, a risk estimation model was developed which is a first attempt to classify patients into risk categories. RESULTS: Male gender, age below 60 or between 60 and 74 years, living alone, no occupation, bypass surgery, NYHA status II, III or IV and chest pain were identified as risk factors to determine impaired HRQL. The model explains 29.13% of the variance. Based on the risk estimation model 27.4% were classified as medium or high risk. CONCLUSIONS: For the first time a multilevel method was applied to evaluate HRQL after heart surgery showing that socio-demographic variables are important co-factors to dyspnea and chest pain. We take a first attempt in developing a new approach that should encourage further research in this field to frame a screening tool that may help identifying patients at risk in the future.

Aortic Valve Neocuspidization with Glutaraldehyde-Treated Autologous Pericardium (Ozaki Procedure) - A Promising Surgical Technique.

In cases of aortic valve disease, prosthetic valves have been increasingly used for valve replacement, however, there are inherent problems with prostheses, and their quality in the so-called Third World countries is lower in comparison to new-generation models, which leads to shorter durability. Recently, transcatheter aortic valve replacement has been explored as a less invasive option for patients with high-risk surgical profile. In this scenario, aortic valve neocuspidization (AVNeo) has emerged as another option, which can be applied to a wide spectrum of aortic valve diseases. Despite the promising results, this procedure is not widely spread among cardiac surgeons yet. Spurred on by the last publications, we went on to write an overview of the current practice of state-of-the-art AVNeo and its results.

Aortic valve neocuspidization with glutaraldehyde-treated autologous pericardium (ozaki procedure) - a promising surgical technique

Abstract In cases of aortic valve disease, prosthetic valves have been increasingly used for valve replacement, however, there are inherent problems with prostheses, and their quality in the so-called Third World countries is lower in comparison to new-generation models, which leads to shorter durability. Recently, transcatheter aortic valve replacement has been explored as a less invasive option for patients with high-risk surgical profile. In this scenario, aortic valve neocuspidization (AVNeo) has emerged as another option, which can be applied to a wide spectrum of aortic valve diseases. Despite the promising results, this procedure is not widely spread among cardiac surgeons yet. Spurred on by the last publications, we went on to write an overview of the current practice of state-of-the-art AVNeo and its results.

Surgical Pulmonary Valve Replacement Due to Failed Percutaneous Pulmonary Valve Intervention in a Patient After Correction of Fallot's Tetralogy: Surgery Remains the Standard.

BACKGROUND One of the most common complications after repair of Fallot's tetralogy is pulmonary valve regurgitation (PR). There are many concepts of treatment, such as surgical, percutaneous, or hybrid pulmonary valve repair. Surgical pulmonary valve replacement is associated with low operative morbidity and mortality and shows very good long-term results. For that reason, it remains the standard of treatment. CASE REPORT We present a case of a 26-year-old male patient who underwent a successful emergent surgical pulmonary valve replacement after a failed percutaneous pulmonary valve intervention, which was performed due to pulmonary regurgitation. CONCLUSIONS Despite the modern (interventional and hybrid) procedures in the treatment of pulmonary valve regurgitation after repair of Fallot's tetralogy, surgical treatment for pulmonary regurgitation still remains the gold standard for young adult patients.

Snugger method - The Oldenburg modification of perceval implantation technique.

We present a modified implantation technique of the Perceval® sutureless aortic valve (LivaNova, London, United Kingdom) that involves the usage of snuggers for the guiding sutures during valve deployment. Both limbs of each guiding suture are pulled through an elastic tube, which is fixed with a Pean clamp, which tightens the sutures and fixes the prosthesis to the aortic annulus during valve deployment. This method proved safe and useful in over 120 cases. Valve implantation was facilitated and the need for manipulation by the assistant or the nurse was eliminated.

Implementation of the aortic no-touch technique to reduce stroke after off-pump coronary surgery.

OBJECTIVES: Despite substantial scientific effort, the relationship between stroke after coronary artery bypass grafting and the use of the aortic no-touch off-pump technique (anOPCAB) remains incompletely understood. The present study aimed to define the effect of anOPCAB on the occurrence and time point of stroke. METHODS: A total cohort of 15,042 consecutive patients underwent surgical myocardial revascularization at a single institution. After establishing anOPCAB as routine procedure, 4695 patients received surgery by 18 different surgeons using the anaortic approach. After the exclusion of all patients with cardiogenic shock and "side-clamp" off-pump coronary artery bypass grafting, 13,279 patients (4485 with anOPCAB) were included in the study. Perioperative strokes were classified as strokes occurring during the hospital stay, with early strokes observed immediately after emergence from anesthesia (vs delayed strokes). RESULTS: The anOPCAB technique reduced the postoperative stroke rate to 0.49% versus 1.31% in on-pump patients (P < .0001). The overall stroke rate after adoption of anOPCAB (0.64%) decreased compared with before its adoption (1.40%; P < .0001). With anOPCAB, the risk of early strokes virtually disappeared to 4 of 4485 patients (0.09%; 95% confidence interval, 0.00-0.18% vs 0.83% in on-pump patients; P < .0001), whereas the incidence of delayed strokes was not affected (0.40% vs 0.48%; P = .5181). The key results were confirmed after adjustment using propensity score-based analyses. CONCLUSIONS: The anOPCAB technique with avoidance of any aortic manipulation is an effective tool to minimize the risk of early strokes during coronary artery bypass grafting, and thus, should be considered as a routine approach. In contrast, additional preventive strategies against delayed strokes remain to be elaborated.

Novel Treatment of a Degenerated Bioroot With the Use of the Sutureless Valve Technique.

We describe 3 patients with severe aortic regurgitation after aortic root replacement using the Freestyle bioprosthesis (Medtronic, Minneapolis, MN). The indication in 2 patients was endocarditis. The third patient showed rupture of the right coronary cusp. To achieve fewer complications, lower operative risk, and reduce operative and cross-clamp times, implantation of a sutureless bioprosthesis in a valve-in-valve manner was performed. A Perceval bioprosthesis (Sorin Biomedica Cardio Srl, Sallugia, Italy) was used in 2 patients, and a 3F Enable bioprosthesis (Medtronic) was used in the other patient. No perioperative complications or in-hospital deaths were observed. We conclude that sutureless aortic valve prostheses offer a safe and feasible option for management of failed homografts.

Current indications for stentless aortic bioprostheses.

The best aortic prostheses have been debated for decades. The introduction of stentless aortic bioprostheses was aimed at improving hemodynamics and potentially the durability of aortic bioprostheses. Despite the good short- and long-term outcomes after implantation of stentless aortic bioprostheses, their use remains limited owing to the technically demanding implantation techniques. Nevertheless, stentless aortic bioprostheses might be of special benefit in certain indications, where they could be a valuable addition to the surgical armamentarium.

Total aortic arch replacement using elephant trunk or frozen elephant trunk technique: a case-control matching study.

BACKGROUND: Surgical management of aortic arch diseases is one of the most challenging issues in cardiovascular surgery. The aim of this study was to compare the outcome after frozen elephant trunk (FET) with conventional elephant trunk (ET) technique. METHODS: Out of a total of 551 patients after thoracic aortic surgery, we analyzed 70 consecutive patients, who underwent aortic arch replacement with ET or FET technique between 2001 and 2017 in our institution. The patients were case-control matched in regard to such variables as age, sex, presence of an acute aortic dissection and necessity for concomitant procedures. The analysis included 25 patient pairs. RESULTS: Among the 25 FET patients, eleven patients were female, the median age was 69, 15 (60%) patients had an aortic dissection and thirteen needed various concomitant procedures. In the second group, treated with conventional ET technique, 10 (40%) patients were female, the median age was 66 years, thirteen presented with an aortic dissection and 16 (64%) underwent concomitant procedures. These and other characteristics did not differ significantly between the groups. In-hospital mortality was statistically similar: 5 (20%) in the FET group vs. 8 (32%) for ET group (P=0.52). The incidence of stroke, acute renal failure and postoperative bleeding was comparable. The length of stay in the intensive care unit did not differ between the cohorts (P=0.258). Predictors of in-hospital mortality were length of the operation, bleeding postoperatively, and acute renal failure. The one-year survival rates were higher in the FET cohort compared to the conventional approach (60% vs. 38%), however without statistical significance. CONCLUSION: In regard to the short- and mid-term outcome, there were only slight differences between both techniques. In patients with extensive aneurysmal aortic disease, conventional ET and FET procedures seem to be associated with acceptable satisfactory mid-term outcome.

The Use of Bilateral Internal Mammary Artery Grafting in Different Degrees of Obesity.

Background Obesity is a limiting factor for the use of bilateral internal mammary arteries (BIMAs). Therefore, we assessed the safety of their use in different degrees of obesity. Patients and Methods We studied two groups of patients with obesity using propensity matching. The first group received single internal mammary artery and saphenous vein grafts (SIMA group, 526 patients) and the second group received bilateral internal mammary arteries (BIMA group, 526 patients). Patients were classified further according to their body mass index (BMI) into overweight (BMI = 25-29.9 kg/m2), obese (BMI = 30-34.9 kg/m2), and severely obese (BMI ≥ 35 kg/m2). Results Preoperative data were similar regarding age (62.78 ± 9.96 vs. 62.98 ± 9.66 years; p = 0.734), female sex (17.5 vs. 18.6%; p = 0.631), diabetes mellitus (26.3 vs. 27.2%; p = 0.74), EuroSCORE (3.21 ± 2.23 vs. 3.18 ± 2.41; p = 0.968), and COPD (16 vs. 16%; p = 1). No significant differences were noticed between the two groups regarding the number of peripheral anastomoses (3.09 ± 0.84 vs. 3.12 ± 0.83; p = 0.633), myocardial infarction (1.7 vs. 1.7%; p = 1), reexploration (1.3 vs. 2.1%; p = 0.34), deep sternal wound infection (DSWI) (2.1 vs. 2.9%; p = 0.43), and 30-day mortality (0.8 vs. 1.1%; p = 0.53). Multivariate analysis identified BMI and intensive care unit stay as independent predictors for DSWI. However, postoperative blood loss (694.56 ± 631.84 vs. 811.67 ± 688.73 mL; p < 0.001) and the incidence of pneumothorax (1 vs. 2.7%; p = 0.037) were higher in BIMA group. Conclusion Patients with obesity can benefit from BIMA grafting. However, postoperative blood loss and the incidence of pneumothorax can be higher using this technique.

Medtronic Freestyle aortic bioprosthesis: a potential option for haemodialysis patients†.

OBJECTIVES: End-stage renal disease patients on regular haemodialysis are at higher risk of calcification. Therefore, many surgeons have concerns regarding the implantation of bioprostheses in such patients. The haemodynamic advantages of stentless aortic bioprostheses support their use; however, these have not been studied yet in end-stage renal disease patients. We studied accordingly the early and mid-term outcomes of aortic valve replacement (AVR) using Medtronic Freestyle stentless aortic bioprostheses in this subset of patients in comparison with stented aortic bioprostheses. METHODS: We retrospectively studied two groups of consecutive patients on regular haemodialysis who required AVR between 2007 and 2013. Non-Freestyle (NFS) group received stented aortic bioprostheses (36 patients) and Freestyle (FS) group received Medtronic Freestyle aortic bioprostheses (48 patients). Follow-up ranged from 2 to 76 months with a mean follow-up of 36.3 ± 25 months. RESULTS: Patients in both groups showed similar demographic characters regarding age (76.4 ± 8.1 vs 74.9 ± 7.2 years; P = 0.35), male gender (58 vs 60%; P = 0.57) and diabetes mellitus (42 vs 48%; P = 0.57). Smaller aortic bioprostheses were implanted in the NFS (23.3 ± 1.2 vs 25.4 ± 2.1; P < 0.001) with consequently higher postoperative mean gradients (14.1 ± 4.1 vs 11.9 ± 5.3 mmHg; P = 0.004). No significant differences were noted regarding postoperative neurological disorder (8 vs 12%; P = 0.73), deep sternal wound infection (3 vs 4%; P = 0.68), re-exploration (8 vs 8%; P = 0.91) and in-hospital mortality (6 vs 4%; P = 0.92). Mid-term follow-up showed higher prosthetic valve calcification and/or sclerosis in NFS group (25 vs 6%; P = 0.015), whereas no significant differences were noticed between the two groups regarding stroke (0 vs 8%; P = 0.13), endocarditis (0 vs 4%; P = 0.50), 36- and 72-month survival (51 ± 2%, 14 ± 4% vs 55 ± 2%, 19 ± 3%, respectively; P = 0.45). CONCLUSIONS: Aortic bioprostheses are a good option for haemodialysis patients requiring AVR, offering acceptable mid-term survival. The Medtronic Freestyle aortic bioprostheses could allow the implantation of larger bioprostheses inferring consequently lower mean gradients, with a potentially higher resistance to calcification and sclerosis in haemodialysis patients.

Telemedicine-guided, very low-dose international normalized ratio self-control in patients with mechanical heart valve implants.

AIM: To study in patients performing international normalized ratio (INR) self-control the efficacy and safety of an INR target range of 1.6-2.1 for aortic valve replacement (AVR) and 2.0-2.5 for mitral valve replacement (MVR) or double valve replacement (DVR). METHODS AND RESULTS: In total, 1304 patients undergoing AVR, 189 undergoing MVR and 78 undergoing DVR were randomly assigned to low-dose INR self-control (LOW group) (INR target range, AVR: 1.8-2.8; MVR/DVR: 2.5-3.5) or very low-dose INR self-control once a week (VLO group) and twice a week (VLT group) (INR target range, AVR: 1.6-2.1; MVR/DVR: 2.0-2.5), with electronically guided transfer of INR values. We compared grade III complications (major bleeding and thrombotic events; primary end-points) and overall mortality (secondary end-point) across the three treatment groups. FINDINGS: Two-year freedom from bleedings in the LOW, VLO, and VLT groups was 96.3, 98.6, and 99.1%, respectively (P = 0.008). The corresponding values for thrombotic events were 99.0, 99.8, and 98.9%, respectively (P = 0.258). The risk-adjusted composite of grade III complications was in the per-protocol population (reference: LOW-dose group) as follows: hazard ratio = 0.307 (95% CI: 0.102-0.926; P = 0.036) for the VLO group and = 0.241 (95% CI: 0.070-0.836; P = 0.025) for the VLT group. The corresponding values of 2-year mortality were = 1.685 (95% CI: 0.473-5.996; P = 0.421) for the VLO group and = 4.70 (95% CI: 1.62-13.60; P = 0.004) for the VLT group. CONCLUSION: Telemedicine-guided very low-dose INR self-control is comparable with low-dose INR in thrombotic risk, and is superior in bleeding risk. Weekly testing is sufficient. Given the small number of MVR and DVR patients, results are only valid for AVR patients.

Are aortic valve reoperations after primary replacement with stentless heart valve prostheses more demanding than after stented biological prostheses?

OBJECTIVE: Reoperations after aortic valve replacement (AVR) with stentless valve prostheses are believed to be surgically more difficult than after stented prostheses. METHODS: Between January 1996 and December 2006, 1,340 of 3,785 patients with AVR in a single institution received a stentless valve prosthesis in aortic position (Medtronic Freestyle, Medtronic GmbH, Meerbusch, Germany). Reoperations after stentless AVR occurred in 27 patients (2.0%). Twenty-four of these patients were compared with another 24 patients having redo surgery after a primary stented bioprosthesis after carrying out propensity score matching. RESULTS: After matching, stentless valve redo patients had a similar preoperative risk profile regarding EuroSCORE (stentless 10 ± 3 points/stented 11 ± 3 points; p = 0.37), preoperative active endocarditis (stentless 37.5%/stented 16.7%; p = 0.081), and amount of concomitant procedures (stentless 37.5%/stented 16.7%; p = 0.222). Thirty-day mortality after reoperation was 20.8% (5 patients) in the stentless and 4.2% (1 patient) in the stented group (p = 0.081), and reintubation rate was 16.7% in the stentless and 0% in the stented group (p = 0.037). Aortic clamping time (stentless 90 ± 25 min/stented 86 ± 34 min; p = 0.208) and extracorporeal circulation time (stentless 151 ± 59 min/stented 132 ± 52 min; p = 0.55) were similar in both groups. CONCLUSION: Our data do not show that the technical difficulty of reoperations after stentless AVR is higher than that of reoperations after stented AVR. The clinically visible, but not statistically significant, higher early mortality rate of our stentless group is mainly due to more active valve prosthesis endocarditis cases and a higher amount of concomitant procedures.

72 hours standby time of wet-primed cardiopulmonary bypass circuits: a microbiological quality assurance study.

In a microbiological sample study of 15 wet-primed cardiopulmonary bypass circuits in standby mode for 72 hours under regular clinical conditions, no contamination of the priming fluid or the connectors could be detected. Hand contact surfaces of the machines demonstrated environmental microorganisms. These findings indicate the safe use of primed cardiopulmonary bypass circuits in standby mode for 72 hours. A surface disinfection of hand contact surfaces immediately before use is recommended.

The history of the management of sternal osteomyelitis and mediastinitis - from Hippocrates until today.

Even during the time of Hippocrates, Galen and their colleagues recognized mediastinal affections. However, they were not considered with the surgical treatment. First progress in the treatment options of this severe disease, still denoted as 'terra incognita', over to today's gold standard are pictured. The mediastinitis-registry which was founded by the German Society for Thoracic and Cardiovascular Surgery (DGTHG) in 2011 and the recent establishment of the study group to adopt a guideline 'diagnosis and therapy of postoperative mediastinitis/sternal osteomyelitis following cardiac surgery' are attempts to a standardization of the treatment. Substantial advancement in the treatment of postoperative mediastinitis could be achieved in the past. The mortality dropped as low as less than 10%. With these implementations more benefit for the patients' outcome can be expected.

Process review of a departmental change from conventional coronary artery bypass grafting to totally arterial coronary artery bypass and its effects on the incidence and severity of postoperative stroke.

BACKGROUND: We evaluated the process of changing from conventional coronary artery bypass grafting (CABG) to totally arterial off-pump coronary artery bypass (TOPCAB) at a single heart center in Germany. METHODS: We (1) used multivariate statistical methods to assess real-time monitoring of OPCAB effects, (2) conducted a case review to assess preventable deaths and identify areas of improvement, (3) conducted a team survey, and (4) evaluated benchmarking results. RESULTS: All surgeons and assistants (n = 18) at this center were involved and were guided by the department head and one of the consultants, who was trained in this procedure in 2004 at the Leuven OPCAB school. The frequency of OPCAB operations increased abruptly in 2005 from 5% to 43% and then increased gradually to 67% (n = 546) by 2008 (total, 1781 OPCAB cases and 1563 on-pump cases). The in-hospital and 30-day mortality rates for OPCAB surgeries (n = 10 [0.6%] and 21 [1.2%], respectively) were lower than for on-pump surgeries (n = 27 [1.7%] and 26 [1.7%], respectively). Stroke rates were also lower for OPCAB surgeries (7 cases [0.4%] versus 15 cases [1%]). The lower risk of stroke in the OPCAB group was significant (P < .05) after risk adjustment. Monitoring curves and case reviews demonstrated a preventable death percentage of at least 30%. The attitude of the team was mostly positive because of the promising results (eg, fewer strokes, increasing TOPCAB popularity, and a top national rank). CONCLUSIONS: The change from conventional CABG to TOPCAB was effective in decreasing the incidence and severity of stroke, in developing a team routine and a positive team attitude, and in producing excellent benchmarking results. The presence of a training and communication deficiency at the beginning of the study suggested an area for further improvement. After 6 years TOPCAB had largely replaced conventional CABG.

Management of protamine allergy with bivalirudin during coronary artery revascularization.

A patient with impaired left ventricular function was scheduled for coronary artery bypass grafting. The patient's history revealed a life-threatening allergy to fish proteins. Therefore, because of the threat of cross-reactivity to protamine, a standard anticoagulation protocol with heparin/protamine was disapproved. Instead, complete coronary artery revascularization was successfully performed off-pump using bivalirudin as the anticoagulant.

The late impact of surgical skills and training on the subcoronary implantation of the Freestyle stentless bioprosthesis.

BACKGROUND AND AIM OF THE STUDY: Recent data have demonstrated an impact of higher postoperative mean pressure gradient (MPG) across the subcoronary Freestyle stentless bioprosthesis on the mid-term quality of life, but not on that of survival. Thus, the question remains that, with a prolonged follow up, would an effect on duration of survival also evolve? METHODS: Between 1996 and 2006, a total of 939 patients underwent aortic valve replacement (AVR) for aortic stenosis with the Freestyle stentless bioprosthesis, using the subcoronary technique. A follow up was conducted by mailed questionnaires, and completed by telephone interviews in September 2008. The follow up was 99% complete and totaled 3,468 patient-years (pt-yr); the mean follow up time was 7.7 years (range: 7.3-8.1 years). The maximum follow up was 11.9 years. RESULTS: Actuarial survival rates at five and 10 years were 73 +/- 2% and 35 +/- 4%, respectively. The cut-off gradient was identified at a postoperative MPG of 20 mmHg, where a gradient >20 mmHg had a negative impact on survival rate (p = 0.008), as indicated by the greatest fall of deviance in the Akaike information criterion. Risk factors also affecting survival rate included atrial fibrillation, diabetes, higher serum creatinine levels, greater age, left ventricular ejection fraction < or = 40%, liver insufficiency, lower body mass index, chronic obstructive pulmonary disease, and peripheral arterial disease. Risk factors for MPG >20 mmHg were a smaller valve size, a higher preoperative gradient, individual surgeons and lesser cumulative experience, and early adopters (surgeons) of the subcoronary stentless valve implantation technique. CONCLUSION: A higher MPG impedes long-term survival, with the cut-off being at 20 mmHg. A higher MPG was largely influenced by the individual surgeons and their cumulative experience of using the subcoronary technique. Late adopters of the technique profited from the observations of early adopters. The standardization of a surgical technique and the identification of common pitfalls were key to optimizing the surgical outcome after stentless valve implantation.