Impact of implant technique following freestyle stentless aortic valve replacement

BACKGROUND: Stentless aortic bioprostheses have excellent hemodynamics and clinical outcomes. The purpose of the present study was to determine whether implant technique of the Freestyle aortic root bioprosthesis impacts clinical outcomes or hemodynamic performance. METHODS: The long-term multicenter study of the Freestyle stentless aortic bioprosthesis includes 500 consecutive patients implanted using the subcoronary and 162 using the full root technique. Clinical outcomes and echocardiographic hemodynamics were compared through 5 years. RESULTS: There were no differences between groups in time to death, valve-related death, or reoperation. The incidence of operative death was higher in the full root than in the subcoronary group (odds ratio 3.97, p = 0.001). Patients in the subcoronary group were more likely to have New York Heart Association functional class III or IV symptoms at 1 year (1.7% versus 0%, p = 0.04) and 5 years postoperatively (4.4% versus 0%, p = 0.02). Mean gradient was lower (p = 0.0004) and effective orifice area larger (p = 0.04) in the full root group. Left ventricular mass index decreased in both groups. The preponderance of patients in both groups had no or trivial aortic regurgitation through 5 years. CONCLUSIONS: Full root implantation of the Freestyle stentless aortic bioprosthesis was associated with higher operative mortality, but somewhat better hemodynamics, functional class, and freedom from aortic regurgitation. Higher operative mortality argues against the empiric replacement of the ascending aorta in the absence of aortic root pathology. In appropriately selected patients, both implant techniques are viable alternatives for valve implantation.     

Commissural detachment and Valsalva sinus dilatation after implantation of Prima Plus stentless valve with full root technique

The stentless aortic bioprosthesis has been used because of its excellent hemodynamics and few valve-related complications. We report a case of redo aortic root replacement for severe aortic regurgitation and dilatation of the Valsalva sinus 7 years after the implantation of a Prima Plus aortic root bioprosthesis (Edwards LifeScience, Irvine, CA, USA) using a full root technique. Intraoperative findings showed the complete detachment of the commissure between the left and non-coronary cusps, and Valsalva sinus dilatation of the porcine aortic root bioprosthesis. Redo aortic root replacement with a 23-mm porcine bioprosthesis and 28-mm straight graft was performed. There were no findings of intimal tear, suture dehiscence, degeneration, and perforation of the bioprosthesis. Such complications associated with the Edwards Prima Plus aortic root bioprosthesis were rarely reported. Commissural detachment of a porcine stentless aortic bioprosthesis can occur; thus, careful follow-up involving echocardiography and computed tomography is necessary.     

Aortic valve replacement with stentless porcine aortic bioprosthesis

Twenty-nine patients were entered in a clinical trial on aortic valve replacement with a stentless glutaraldehyde-fixed porcine aortic valve. This bioprosthesis is secured to the aortic root by the same technique used for aortic valve replacement with aortic valve homografts. The functional results obtained from this operation have been most satisfactory. To assess the hemodynamic benefit of eliminating the stent of a porcine aortic valve, we matched 22 patients with a stentless porcine bioprosthesis for age, sex, body surface area, valve lesion, and bioprosthesis size to 22 patients who had aortic valve replacement with a Hancock II bioprosthesis. Mean and peak systolic gradients across the aortic bioprosthesis and effective aortic valve areas were obtained by Doppler studies. Gradients across the stentless bioprosthesis were significantly lower than gradients across the Hancock II valve for every bioprosthesis size. Effective aortic valve areas of the stentless bioprosthesis were significantly larger than the valve areas of the Hancock II valve. Our data demonstrate that the hemodynamic characteristics of a glutaraldehyde-fixed porcine aortic bioprosthesis are greatly improved when the aortic root is used as a stent for the valve. This technique of implantation is expected to enhance the durability of the bioprosthesis, because the aortic root may dampen the mechanical stress to which the leaflets are subjected during the cardiac cycle.     

Medtronic Freestyle Aortic Root Bioprosthesis: Implant Techniques

BACKGROUND: The Medtronic Freestyle aortic root bioprosthesis is a complete porcine aortic root to allow implantation (1) as a subcoronary valve replacement by removing graft sinus aorta, (2) as a cylinder with the sinotubular junction intact within the aorta (root inclusion), or (3) as a complete aortic root replacement. The choice among the three implant techniques depends on surgeon preference or upon the pathology encountered. The advantages and differences among the three implant techniques are examined. METHODS: The Medtronic Freestyle bioprosthesis was implanted in 1163 patients in a Food and Drug administration (FDA) clinical trial between August 1992 and October 1997. There were 21 centers in the international trial using a single data repository. Clinical data was collected prior to and at operation, at 3 to 6 months and annually. The data were compiled and statistical analysis performed at the data center. RESULTS: Patients having subcoronary valve implants were older (80% > 65 years) and aortic occlusion time was about 20 minutes less than the other methods. Patients having aortic root replacement presented with more aortic valve insufficiency (20%). Pathology of the aortic root and ascending aorta requiring repair was 26%, and larger (27 mm) valves were used in 40% of patients. Risk of operation was lowest (5.0%) with subcoronary valve implants and highest (11.7%) with root replacement technique. Thromboembolism was higher, early and late, with root inclusion (3.0, 3.9%/patient per year) and root replacement (3.2, 3.0%/patient per year) than for subcoronary implants (1.8, 1.6%/patient per year). There were more patients taking warfarin at the 4-year point with root inclusion (20%) or root replacement techniques (24%) than among patients having subcoronary implants (14%). Explants of the valve occurred in 2% of patients, none of whom had aortic root replacement. CONCLUSIONS: The Medtronic Freestyle bioprosthesis is an effective and versatile device for replacement of the aortic valve. It offers implant techniques that can treat the aortic root pathology encountered at surgery and allows the operation to proceed according to surgeon preference.     

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.     

A technique of aortic annulus enlargement with a Freestyle stentless bioprosthesis

We describe our surgical technique to manage a small aortic annulus during aortic valve replacement. Starting with the posterior annular enlargement incision described by Manouguian, a stentless porcine aortic root, with excision of the left and right porcine coronary segments and conservation of the mural wall (Freestyle MS design, Medtronic, Minneapolis, MN ), was used. The Freestyle bioprosthesis enlarges the aortic annulus using a direct suture of the valve on the enlarged annulus, and the aorta is closed by a direct suture of the mural wall of the bioprosthesis. Therefore, the aortic annulus enlargement is made only using the aortic bioprosthesis, without other material.     

Aortenklappenersatz mit gerüstlosen Bioprothesen

Stentless valves were designed to improve postoperative hemodynamics in comparison to stented bioprosthesis. The implantation technique of stentless valves is very different from conventional bioprostheses: a stented bioprosthesis maintains its form, due to the rigid stent, whereas the form of a stentless valve depends on the surgical suture lines. The general goal is to snugly fit a stentless valve into the aortic root and, thereby, to ensure optimal hemodynamic results. Insufficient coaptation of the cusps and bulging of the prosthesis into the outflow tract are the results of suboptimal implantation techniques. Residual gradients after stentless valve implantation impede postoperative quality of life and long-term survival. The present paper aims to describe the principles of implantation of stentless valves and to standardize the procedure using the Freestyle prosthesis as an example. The standardization of surgical technique and the identification of common pitfalls are mandatory to avoid unfavorable learning curves and to improve quality of life and long-term survival.     

Aortic Valve Replacement with Stentless Porcine Bioprostheses

The implantation of stentless porcine valves (SPVs) is technically more demanding than implantation of stented bioprosthetic valves. Implantation of the Toronto SPV bioprosthesis requires an,understanding of the relationships between the leaflets and the aortic annulus and sinotubular junction. In addition to proper alignment of the three commissures within the aortic root, the diameter of sinotubular junction should not exceed the external diameter of the porcine aortic valve after completion of the operation. The Medtronic Freestyle porcine aortic root bioprosthesis can be used for subcoronary implantation as well as for aortic root replacement. Degenerative calcification of a tricuspid aortic valve is the most common cause of aortic valve disease in older patients. Implantation of stentless valves in the subcoronary position is usually feasible because the geometry of the aortic root is well maintained in these patients. The bicuspid aortic valve is the second most common cause of aortic valve disease in older patients and the most common in younger patients. These patients frequently have dilated aortic root, and the Medtronic Freestyle bioprosthesis is ideal for implantation using the root inclusion technique. Stentless porcine bioprostheses are minimally obstructive and associated with low mean systolic gradients. In addition, they have better hemodynamic performance during exercise than stented bioprostheses. For these reasons, patient-prosthesis mismatch has not been described with stentless valves. Left ventricular function after aortic valve replacement appears to be better with stentless than with stented bioprostheses. Comparative, nonrandomized studies of aortic valve replacement with stented and stentless valves suggest that the risk of cardiac death is reduced with stentless valves and the rates of valve-related complications also appear to be lower. What remains unknown is whether stentless valves are more durable than stented ones.     

Surgical treatment of double-outlet left ventricle in 2 patients with D-position and L-position of the aorta.

Two cases of double-outlet left ventricle (DOLV) are described, 1 with D-position and 1 with L-position of the aorta. Both patients had situs solitus, atrioventricular concordance with D-relationship of the two ventricles, a ventricular septal defect, and subpulmonary stenosis. The patient with D-position of the aorta was operated on using a technique similar to that for repair of Fallot's tetralogy but including emergency implantation of a bioprosthesis into the pulmonary artery position on the eighth postoperative day. Surgical correction in the patient with L-position of the aorta required the implantation of a composite valved conduit between the right ventricle and the pulmonary artery. The various surgical techniques for correction of DOLV are described, and the literature is reviewed. Postoperative right heart failure in both patients is explained by the impaired function of the right ventricle being exposed to gross pulmonary incompetence or by the persistence of elevated right ventricular pressure.     

Stentless aortic root bioprosthesis implantation and coronary artery bypass grafting in a patient with single right coronary artery.

Coronary arteries with anomalous origin from the aorta can be a risk factor during aortic root procedures. We report on the successful management of aortic root surgery in a 76-year-old man with a single coronary ostium. Preoperative computed tomography and angiography revealed an anomalous course of the left main coronary artery from the right sinus of Valsalva. A stentless aortic root bioprosthesis (Prima Plus) was implanted using a modified subcoronary technique. The origin of the left main coronary artery was approximately 2 mm beyond the ostium of the common trunk. Attention to the anatomic relationship of the anomalous coronary arteries to the aorta by clarifying the anatomy of coronary arteries in advance allowed us to safely perform aortic root surgery in a patient with an anomalous origin of the coronary arteries.     

Reoperation due to failure of a Freestyle bioprosthesis

We report re-do aortic valve and ascending aorta replacements by using the valve-on-valve technique for primary tissue failure of a Freestyle bioprosthesis. A 74-year-old male, who had had a 25 mm Freestyle bioprosthetic valve implanted by the sub-coronary method 5 years previously for aortic valve regurgitation due to congenital bicuspid valve, was referred to our hospital for dyspnea and palpitation. He presented with heart failure secondary to aortic regurgitation due to primary tissue failure, and computed tomography demonstrated an enlarged ascending aorta (5 cm in diameter). The operative findings revealed that the Freestyle bioprosthetic valve had a leaflet tear at the left coronary cusp. We replaced the degenerated Freestyle bioprosthesis with a 19 mm Mosaic aortic bioprosthesis by using the valve-on-valve technique, and ascending aorta replacement was performed simultaneously. This technique can be useful for re-do surgery for degenerated stentless valves to avoid potential risks of complete excision of the bioprosthesis.     

Aortic root replacement with a valved conduit containing a stented xenograft.

The Bentall operation is a well-established procedure for aortic root replacement, generally contemplating the use of a mechanical valve substitute. We have devised a simple modification by which a stented bioprosthesis is sutured inside, rather than at the extremity, of a vascular tube graft. This facilitates the technique of implantation and may simplify a redo procedure in case of valve failure.     

Aortic Valve Replacement with the Unique Suture Line Stentless USL Porcine Valve: A New, Simple, and Safe Stentless Valve Implantation Technique

The Stentless USL, Unique Suture Line porcine valve, is a stentless bioprosthesis developed following the advantages of the studies of the physiology of the aortic root as a functional unit. The direct suturing of the porcine tissue on the soft and elastic tissue of the host's aortic annulus and root gives the bioprosthesis the possibility to follow the physiological movements of the natural valve during the cardiac cycle. For the same reason, there is decreased stress on the valve tissue, especially at the commissural level. There is less technical demand for surgeons who have limited experience with the freehand or miniroot technique due to the limited availability of the homografts because the Stentless USL valve can be implanted with the same technique used with a conventional stented valve. The implant technique used for the Stentless USL valve has advantages, especially in the small aortic calcified annulus in elderly patients where the freehand technique can be difficult and the second suture line can be dangerous (i.e., coronary ostium near the aortic ring or in calcified aortic wall). Our experience with this stentless valve in approximately 200 patients (> 70 years old) shows it to have excellent hemodynamic results even in small valve sizes. The use of this valve and the simple implantation technique avoids the need for complicated aortic root enlargement procedures.     

Aortic valve replacement with a stentless porcine aortic root bioprosthesis

From April, 1999 to November, 1999, 8 patients underwent the aortic valve replacement using Medtronic Freestyle aortic root bioprosthesis. Mean age was 67.8 years old. Aortic valve etiology was as follows, AS: 1 case, AR: 2 cases, ASR: 3 cases, IE: 1 case, mechanical valve malfunction due to subvalvular pannus: 1 case. The implanted valve size was 25: 2 cases, 23: 3 cases, 21: 1 cases, 19: 2 cases. Surgical technique was subcoronary: 7 cases, full-root: 1 case. Post-op 2D-echo revealed tribial aortic valve incompetence in two cases because of size discrepancy between the aortic annulus and the ascending aorta. Pacemaker implantation was needed in 1 case because of the complete A-V block. In comparison with 5 cases of aortic valve replacement with Hancock II performed in same period, there were no significant differences about the implanted valve size and mean systolic pressure gradient, but the effective orifice area in Freestyle cases was significantly larger than Hancock II cases.     

A Smart Method of Intraoperative Explantation of an Aortic Bioprosthesis

Abstract   Structural prosthetic valve deterioration and nonstructural dysfunction are two common causes of nonfatal valve events following implantation of a bioprosthetic valve. Using caution and skill, implantation of a bioprosthesis is relatively easy. On the other hand, explantation of a bioprosthesis is a challenging and time-consuming procedure. We have developed a surgical technique by which we were able to ameliorate this troublesome situation in a 79-year-old man with aortic stenosis in whom we had to intraoperatively explant the bioprosthesis that we have put in initially. Another bioprosthesis of the same kind was used to replace the old prosthesis with the rest of his postoperative course until dismissal being eventless.     

A modified valve-on-valve approach for aortic root replacement

We describe an alternative surgical technique for aortic root replacement in a patient whose aortic valve was previously replaced with a bioprosthesis. It consists of resecting the leaflets of the original bioprosthesis in situ, amputating the struts, and suturing the skirt of a composite graft on the preserved annulus of the original bioprosthesis. Coronary circulation is reconstructed according to the Cabrol modification. This approach simplifies and shortens the procedure of aortic root replacement, minimizing the potential hazard of hemorrhage from the proximal suture line in these cases.     

Repair of an aneurysm of the pulmonary trunk in a 65-year-old patient

The case of a 65-year-old patient with asymptomaticaneurysm of the pulmonary trunk associated with severe insufficiency of the pulmonary valve and symptomatic coronary artery disease is presented. The surgical procedure included coronary artery bypass grafting, aneurysmectomy, and pulmonary artery replacement with implantation of a stentless bioprosthesis and lengthening of the root of the bioprosthesis with a reversed vascular Y prosthesis, which was anastomosed to the left and right pulmonary artery.     

Aortic root remodeling with the "cuff" technique for stentless valve implantation

Aortic root and sinotubular junction dilatation and aneurysm of ascending aorta are considered relative contra-indications to implantation of a stentless valve prosthesis, because the modified aortic geometry leads to aortic incompetence and early failure of the prosthesis. Aortic root reconstruction can be performed according to various techniques. We present a surgical technique in which a tubular graft, replacing an ascending aortic aneurysm, allows sinotubular remodeling and satisfactory implantation of a stentless prosthesis. The native aorta is inserted into the vascular prosthesis at the level of the sinotubular junction which is wrapped in order to prevent commissure spreading. Sizing of the vascular and valve prosthesis is made according to annular diameter. Since October 1999, 6 patients have been operated using this technique with good results.     

Extended hockey stick aortotomy for Perceval valve implantation: How to reshape the aortic root

The Perceval valve is a true sutureless aortic bioprosthesis. Overall, excellent performances have been demonstrated in terms of hemodynamic outcomes, safety, and versatility of use; furthermore, as a sutureless valve option, it has shown to reduce the surgical burden, shortening the operative times, and simplifying minimally invasive procedures. Since the valve has got a high frame profile, the recommended implantation technique requires a high and transverse aortotomy. In case of unplanned Perceval valve implantation, when an extended aortotomy is required, we have come up with a simple technique to reshape the aortic root before the valve is delivered in place: symmetry is pivotal to prevent folding issues and to improve the annular sealing. Although we discuss an out‐of‐recommendation use, in our experience that technique has shown to be safe and effective.     

Successful implantation of self-expanding valve for a failed stentless prosthesis

Valve-in-valve transcatheter aortic valve implantation is currently used for failed bioprosthesis. The use of a transcatheter prosthesis in a regurgitant noncalcified root implanted Medtronic Freestyle prosthesis is particularly challenging. We present a successful transaxillary valve-in-valve implantation of a self-expandable transcatheter aortic valve prosthesis in a failed Freestyle bioprothesis implanted eleven years earlier. Tips and tricks are discussed.