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Sutureless Perceval S Aortic Valve Replacement: A Multicenter, Prospective Pilot Trial Malakh Shrestha1, Thierry Folliguet2, Bart Meuris3, Alain Dibie2, Christoph Bara1, MarieChristine Herregods3, Nawid Khaladj1, Christian Hagl1, Willem Flameng3, Francois Laborde2, Axel Haverich1 1
Division of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany, Cardiac Medico-Surgical Department, Institute Mutualiste Montsouris, Paris, France, 3Cardiac Surgery, U.Z. Gasthuisberg, Leuven, Belgium
2
Background and aim of the study: A European, multicenter, prospective, non-randomized, clinical pilot trial was designed to evaluate the feasibility of the Perceval S sutureless aortic valve prosthesis. A clinical and echocardiographic follow up was performed at the time of hospital discharge and subsequently after one, three, six, and 12 months. Methods: The valve was implanted following sternotomy, extracorporeal circulation (ECC), aortic cross-clamping, cardioplegic arrest, and removal of the native valve. Implantation suturing was not required. Optimal annular sealing was obtained with brief low-pressure balloon dilation. If coronary bypass was indicated, a distal anastomosis was performed first. Between April 2007 and February 2008, 30 patients (mean age: 81 ± 4 years) underwent aortic valve replacement. The prevalence of pure aortic stenosis was 76.7%, and that of mixed lesion 23.3%. The mean logistic EuroSCORE was 13.18%, and the NYHA class was III and IV in 93.3% and 6.7% of patients, respectively. The implanted valve size was 21 and 23 mm in 37% and 63% of patients, respec-
tively, and 14 (46.7%) underwent coronary artery bypass grafting (11 internal mammary artery, nine vein grafts). Results: The mean aortic cross-clamp and ECC times were 34 ± 15 min and 59 ± 21 min, respectively. There was one in-hospital death (3.3%), and three deaths occurred within 12 months of follow up (one death was valve-related, and two deaths were independent of the valve implantation). A total of 28 patients was assessed at one month post-implantation, and 23 after 12 months. No migration or dislodgement of the valve had occurred, but there were two mild paravalvular leakages and two mild intravalvular insufficiencies. Conclusion: The preliminary results of the trial confirmed the safety and efficacy of the Perceval S sutureless aortic valve. In this high-risk subset of patients, shortening the aortic cross-clamp and ECC times may help to reduce mortality and morbidity.
Currently, minimally invasive and/or interventional aortic valve implantation is gaining a broader clinical application. It is thought that this mode of intervention is especially suitable for elderly or other high-risk patients, who would not qualify for a conventional aortic valve operation (1-7). In this context, transfemoral and transapical approaches have attracted increasing interest in clinical practice. Despite a broader use of these techniques, they are not free from perioperative and postoperative complications, such as embolism associated with balloon dilatation of the native valve, a risk of malposition of the valve, and an
increased risk of heart block requiring pacemaker implantation. Furthermore, these methods are not feasible in patients with concomitant pathologies, such as multivessel coronary artery disease (CAD) and left main stem stenosis. A European, multicenter, prospective, non-randomized, clinical pilot trial was therefore designed to evaluate the feasibility of the Perceval S sutureless prosthesis in 30 elderly patients requiring aortic valve replacement (AVR) via a conventional median sternotomy with extracorporeal circulation (ECC) and aortic cross-clamping.
Address for correspondence: Dr. med Malakh Shrestha, Division of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hanover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany e-mail:
[email protected]
The Journal of Heart Valve Disease 2009;18:698-702
Clinical material and methods Patients Between April 2007 and February 2008, 30 consecutive patients (16 in Hannover, seven each in Paris and
© Copyright by ICR Publishers 2009
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Figure 1: The Perceval S valve.
Leuven) that fulfilled the study inclusion criteria (Table I) underwent aortic valve implantation, performed by two surgeons at each center. All patients selected for this study had significant aortic valve disease, and 14 had concomitant CAD. The patient characteristics are listed in Table II. Approval for the study was granted by the Institutional Review Boards of the University Hospitals involved, and all patients provided their written, informed consent. The Perceval S aortic valve The Perceval S prosthetic valve comprises a functional component in bovine pericardium fixed in a metal cage made from a super-elastic alloy (Fig. 1). The cage design is characterized by two ring segments, on the proximal and distal ends, and connecting elements designed to support the valve; these allow the prosthesis to anchor to the aortic root, in the sinuses of Valsalva. The material used to construct the cage is an equiatomic alloy of nickel and titanium, known as nitinol. This material is able to accept strong deformation and return to its original shape after the force has been removed. Therefore, the cage can be compressed for the implantation and then released to reach its final diameter.
Figure 2: At surgery, each thread was passed into a slot corresponding to the median part of the prosthetic sinus.
The functional valve component is identical to the Sorin Pericarbon bovine pericardium valve, fixed into the cage by sutures. In correspondence with each valve sinus, the Perceval S ring has three loops through which guide threads are passed to aid prosthetic positioning. For this initial study, two valve sizes (21 and 23 mm) were available. Surgical procedure The heart was exposed via a median sternotomy. After systemic heparinization, the patient was placed on ECC in the usual manner. The aorta was crossclamped and cardioplegia administered. A transverse aortotomy was made 1 cm distal to the sinotubular junction, so as to leave an edge free for closure of the aortotomy after implantation of the device. The diseased, native aortic valve was removed and the aortic annulus completely decalcified. In order to ensure correct positioning of the prosthesis, three
Table I: Patient recruitment inclusion and exclusion criteria. Inclusion criteria • Age ≥75 years • High risk for aortic valve stenosis; standard surgical intervention candidate • NYHA functional class III and/or IV • Small and calcified aortic root, annulus Exclusion criteria • Aneurysmal dilation (>4 cm) or dissection of ascending aorta requiring correction • Aortic annulus, after de-calcification; not suitable for a 21 or 23 mm valve
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M. Shrestha et al. Table II: Characteristics of patients at the time of valve implantation (n = 30). Parameter Gender ratio (M:F) Age (years)* Height (cm)* Body weight (kg)* Body surface area (m2)* Aortic valve pathology NYHA class III IV Aortic stenosis Combined pathology Coronary artery disease Logistic EuroSCORE (%)* LVEF (%)*
Table III: Intraoperative data among patients (n = 30). Parameter
Value 8:22 81 (76-88) 160 ± 7.2 (147-178) 71 ± 15 (47-110) 1.7 ± 0.2 (1.31-2.17)
CPB time (min)* ACC time (min)* Valve size (mm) 21 23
Concomitant CABG (n = 14) 73.4 ± 21.8 (41-130) 40 ± 19 (16-79)
Isolated AVR (n = 16) 46.4 ± 6.7 (34-60) 29 ± 8 (23-55)
11 19
*
28 (93.3) 2 (26.7) 23 (76.7) 7 (23.3) 14 (46.7) 13.18 ± 7.28 (5.48-39.07) 63 ± 11 (45-85)
*
Values are mean ± SD (range). Values in parentheses are percentages. LVEF: Left ventricular ejection fraction.
guiding threads were used (mono-ply 3/0) as reference for accurate alignment of the inflow section of the prosthesis with the insertion plane of the native leaflets. These threads were positioned in the lowest part of the native leaflet insertion line for each valve sinus. At the prosthesis level, each thread was passed into a slot corresponding to the median part of the prosthetic sinus (Fig. 2). The release device was inserted into the aorta to the point where it was blocked by pulling the previously positioned thread guides. The valve prosthesis, loaded into the delivery device, was released in two phases: first, the inflow section was opened, after which the outflow part was opened. Full release of the prosthesis was obtained only after the latter procedure. When the prosthesis had been completely deployed the thread guides were removed. In order to optimize the area of contact between the prosthesis and the aortic annulus, a post-dilatation was performed using a balloon catheter at a pressure of 2 atmos. Postoperatively, the patients received treatment with coumadin for two months, according to the standard anticoagulation protocol following biological AVR.
Results The valves were successfully and firmly positioned, under visual control, in all patients; no deaths occurred during the procedure. In total, 14 patients underwent concomitant coronary revascularization (coronary artery bypass grafting; CABG), as interventional therapy was not possible due to the location and/or extension of the stenosis. The intraoperative data are
Values are mean ± SD (range). ACC: Aortic cross-clamp; CPB: Cardiopulmonary bypass.
presented in Table III. One patient died during the hospital stay due to sudden cardiac death. At autopsy, however, no valve-related pathology was revealed and the valve was seen to be seated appropriately inside the aortic annulus, with patent coronary ostia. Three patients died within the 12-month follow up period after hospital discharge: one death was due to an accident, one to multiorgan failure, and a third to endocarditis. No autopsies were performed on these patients. Postoperative complications included cardiac tamponade due to mediastinal bleeding (n =1), atrioventricular conduction block (n =1), wound infection (n =1), and gastrointestinal bleeding (n =1). There was one case of a peripheral thromboembolism. All patients underwent an echocardiography control before discharge. At one year, there were two mild paravalvular leakages and two mild intravalvular insufficiencies which remained stable over this time period. Furthermore, no migration or dislodgement of the prosthesis had occurred during further follow up. The follow up data are listed in Tables IV and V. Three patients were lost to the in-hospital follow up (all were alive and followed by their general practitioner).
Discussion A sutureless aortic valve was implanted, following thorough surgical removal of the diseased valve, in 30 patients recruited at three different European hospital locations. As a result of this first trial, treatment and prognosis would suggest successful valve positioning and implantation, without any diminished blood flow to the coronary ostia. In addition, no evidence of paravalvular leakage, as assessed by intraoperative echocardiography, was detected. Furthermore, 14 patients required a simultaneous CABG, completed without additional risk to the patient. The shortest aortic cross-clamp time among these patients was 16 min, corresponding to an ECC time of 41 min. Surgical AVR represents the ‘gold standard’ of treat-
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Table IV: Hemodynamics at 12 month follow up (n = 23). Parameter
Mean ± SD Median (range)
Max gradient (mmHg)
Mean gradient (mmHg)
Orifice area (cm2)
21 ± 9 18 (4-42)
10 ± 5 8 (2-21)
1.6 ± 0.4 1.6 (1-2.3)
ment in patients with aortic valve stenosis. Often, symptomatic patients have significant comorbidities, and in such subsets of patients conventional surgical replacement may pose a high perioperative risk. Given the aging population, the number of these patients is increasing. According to the STS data base, the number of patients older than 80 years has increased from 12% to 24% over the past 20 years. In addition, the proportion of candidates requiring concomitant CABG has risen from 5% to 25% during the same time interval. In these patients, it is well known that both, the risk of perioperative strokes, as well as perioperative impairment requiring dialysis is modestly increased. Therefore, concepts of AVR avoiding long ischemia times, as well as long periods of ECC, would be accepted among the surgical community. On the other hand, recent reports of the surgical outcome in high-risk populations of elderly patients have shown, in fact, that AVR can safely be performed by applying recent advances in cardiosurgical techniques, such as minimizing access to valve replacements and optimizing myocardial preservation. These recent reports have also challenged the use of the EuroSCORE to assess perioperative risk in elderly patients, as advancing age represents a too-high risk assumption in this scoring system. Nevertheless, novel advances in aortic valve implantation must be critically and cautiously evaluated relative to the most recent data collected on conventional surgical methods in this subgroup of patients (8). Percutaneous aortic valve implantation has been proposed as an alternative to an interventional
Table V: NYHA functional class among patients with complete follow up (n = 23). NYHA class
Preoperative
12-month follow up*
I II III IV
28/30 (93.3) 2/30 (6.7)
13/23 (57) 9/23 (39) -
*
One patient was not available for the follow up examination. Values in parentheses are percentages.
approach by several groups. The technique was first conducted using a transvenous-transeptal procedure with antegrade access to the aortic valve by Cribier et al. (1), with the first clinical report on the method and patient outcome being made subsequently by Grube and colleagues (2). In addition, Webb et al. performed aortic valve implantation, using this method, in highrisk patients (mean EuroSCORE = 28) and reported a procedural mortality of 12% (9). While this concept of percutaneous transfemoral aortic valve implantation has gained further acceptance worldwide, a more surgical approach of transapical aortic valve implantation has been simultaneously developed. Thus far, the group in Leipzig has led the way with their pioneering work in more than 100 patients, whereby the stroke risk has been significantly reduced compared to that associated with a transfemoral approach. However, the data collected up to one year post-procedure have shown a significant risk with respect to morbidity or mortality (5,6). In neither of the aforementioned alternatives is the diseased valve removed; rather, the calcified aortic root is dilated using angioplasty. However, one consequence of this approach is the potential dislodgement of calcium debris, resulting in peripheral and central embolism (9). The occlusion of coronary arteries from debris released by aortic valve balloon dilatation, in addition to malpositioning of the valve under fluoroscopy, have also been reported (9). Associated with valve malpositioning are paravalvular leaks, requiring the patient to undergo further surgery by conventional means (6). Based on the available data, a percutaneous approach to aortic valve implantation is still considered experimental, including the procedures performed in high-risk patients. It is believed that the higher rate of complications associated with these techniques are due to: (i) balloon dilatation of a calcified aortic valve; (ii) surgery concomitant with a beating heart; and (iii) surgery not requiring suturing. Thus, these combined steps create the risk for embolisms, malpositioning of the graft, and/or paravalvular leakages. Lastly, these approaches do not allow for the treatment of combined pathologies of the aortic valve and the coronary arteries. Since an interventional therapy of CAD is not possible in all patients, one advantage of this technique is
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2. Grube E, Laborde JC, Zickmann B, et al. First report on a human percutaneous transluminal implantation of a self-expanding valve prosthesis for interventional treatment of aortic valve stenosis. Catheter Cardiovasc Interv 2005;66:465-469 3. Hanzel GS, Harrity PJ, Schreiber TL, O’Neill WW. Retrograde percutaneous aortic valve implantation for critical aortic stenosis. Catheter Cardiovasc Interv 2005;64:322-326 4. Lichtenstein SV, Cheung A, Ye J, et al. Transapical transcatheter aortic valve implantation in humans: Initial clinical experience. Circulation 2006;114: 591-596 5. Walther T, Falk V, Borger MA, et al. Minimally invasive transapical beating heart aortic valve implantation: Proof of concept. Eur J Cardiothorac Surg 2007;31:9-15 6. Walther T, Simon P, Dewey T, et al. Transapical minimally invasive aortic valve implantation: Multicenter experience. Circulation 2007;116: I240-I245 7. Webb JG, Chandavimol M, Thompson CR, et al. Percutaneous aortic valve implantation retrograde from the femoral artery. Circulation 2006;113: 842-850 8. Mehta RH, Grab JD, O’Brien SM, et al. Bedside tool for predicting the risk of postoperative dialysis in patients undergoing cardiac surgery. Circulation 2006;114:2208-2216; quiz 2208 9. Webb JG, Pasupati S, Humphries K, et al. Percutaneous transarterial aortic valve replacement in selected high-risk patients with aortic stenosis. Circulation 2007;116:755-763
