Experimental Study and Early Clinical Application Of a Sutureless Aortic Bioprosthesis

INTRODUCTION

The conventional aortic valve replacement is the treatment of choice for symptomatic severe aortic stenosis. Transcatheter technique is a viable alternative with promising results for inoperable patients. Sutureless bioprostheses have shown benefits in high-risk patients, such as reduction of aortic clamping and cardiopulmonary bypass, decreasing risks and adverse effects.

OBJECTIVE

The objective of this study was to experimentally evaluate the implantation of a novel balloon-expandable aortic valve with sutureless bioprosthesis in sheep and report the early clinical application.

METHODS

The bioprosthesis is made of a metal frame and bovine pericardium leaflets, encapsulated in a catheter. The animals underwent left thoracotomy and the cardiopulmonary bypass was established. The sutureless bioprosthesis was deployed to the aortic valve, with 1/3 of the structure on the left ventricular face. Cardiopulmonary bypass, aortic clamping and deployment times were recorded. Echocardiograms were performed before, during and after the surgery. The bioprosthesis was initially implanted in an 85 year-old patient with aortic stenosis and high risk for conventional surgery, EuroSCORE 40 and multiple comorbidities.

RESULTS

The sutureless bioprosthesis was rapidly deployed (50-170 seconds; average=95 seconds). The aortic clamping time ranged from 6-10 minutes, average of 7 minutes; the mean cardiopulmonary bypass time was 71 minutes. Bioprostheses were properly positioned without perivalvar leak. In the first operated patient the aortic clamp time was 39 minutes and the patient had good postoperative course.

CONCLUSION

The deployment of the sutureless bioprosthesis was safe and effective, thereby representing a new alternative to conventional surgery or transcatheter in moderate- to high-risk patients with severe aortic stenosis.     

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.     

Re-do mitral valve replacement using the valve-on-valve technique: a case report.

We report a repeated mitral valve replacement (re-do MVR) using the valve-on-valve technique for a degenerated bioprosthesis. A 49-year-old female, who had had a 29 mm Carpentier-Edwards mitral bioprosthesis for mitral regurgitation 20 years previously, was referred to our institution for dyspnea. She presented with pulmonary edema secondary to severe mitral bioprosthetic valve regurgitation. We replaced the degenerated mitral bioprosthesis with a 25 mm mechanical prosthesis using the valve-on-valve technique, as the struts of the bioprosthesis were embedded in the left ventricular myocardium. Removal of the bioprosthesis may be not only time-consuming but also complicated by cardiac rupture at the atrioventricular junction or the posterior left ventricular wall. The valve-on-valve technique is a simplified procedure that can avoid the potential complications of complete excision of the bioprosthesis. We believe this technique can be a useful strategy for patients with a degenerated mitral bioprosthesis.     

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.     

Conduit-on-valve replacement of a degenerated mitral bioprosthesis with a bioprosthesis

Explantation of a degenerated mitral bioprosthesis with reimplantation of a new bioprosthesis is time-consuming and can be associated with several life-threatening complications. We developed a technique to simplify this procedure and avoid the complications by attaching a new bioprosthesis supported by a pericardium-covered Dacron tube to the intact stent.     

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.     

Delayed rupture of the left ventricle after mitral valve replacement with bioprosthesis.

Rupture of the posterior ventricular wall after mitral valve replacement is a complication rarely reported in the literature. Perforation of the left ventricle after mitral valve replacement with a bioprosthesis has been described in only 3 patients. We have had 2 patients with this complication out of 322 patients who had mitral valve replacement with bioprosthesis. These perforations were caused by impingement of the posterior strut of the bioprosthesis on the posterior left ventricular wall, with intramyocardial hematoma and delayed rupture of the left ventricle.     

A Soviet-made blood vessel bioprosthesis and its clinical use

The authors describe their experience with the using of Soviet made bioprosthesis of blood vessels made of skeleted conserved vein of the human umbilical vein showing its high effectiveness and positive properties such as: high thromboresistent properties of the bioprosthesis and its firmness, the absence of reaction of rejection and pronounced inflammatory reactions of the recipient organism to bioprosthesis, high possibility of the bioprosthesis in remote periods, its fitness for plasty of average diameter 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.     

The Freestyle stentless bioprosthesis for prosthetic valve endocarditis

We report a case of methicillin-resistant Staphylococcus aureus-induced prosthetic valve endocarditis, which was successfully treated with aortic valve replacement using the Freestyle stentless bioprosthesis. The total root and stentless design of this bioprosthesis allows for more radical removal of infected tissue and easier treatment for annular abscess, while requiring less prosthetic materials than a conventional prosthesis. This bioprosthesis thus seems to be a valuable option for active endocarditis.     

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.     

Aortic regurgitation due to perforation of the right coronary cusp 10 years after implantation of a freestyle stentless bioprosthesis

Valve deterioration following aortic valve replacement using the Freestyle stentless bioprosthesis is related to cusp tear, operative injury, or infection. We report a patient with aortic regurgitation due to perforation of the right coronary cusp 10 years after implantation of a Freestyle stentless bioprosthesis in the absence of endocarditis.     

Direct transaortic CoreValve implantation through right minithoracotomy in patients with patent coronary grafts

Transcatheter aortic valve implantation has rapidly gained credibility as a valuable alternative to conventional aortic valve replacement in patients with severe aortic stenosis, who are otherwise left untreated owing to the perceived high risk of operative mortality. However, these patients are often also affected by severe iliofemoral arteriopathy, rendering the transfemoral approach unfeasible. Different alternative access routes have been used in these patients, such the transapical and the subclavian routes. We report our experience of direct aortic access through a right anterior minithoractomy to implant a self-expanding aortic valve bioprosthesis in two patients who had previously undergone coronary artery bypass graft surgery.     

Efficacy of aortic valve replacement with freestyle stentless valve in patients with aortic valve disease

Stentless porcine aortic bioprosthesis has several potential advantages over conventional stented bioprosthesis. The Medtronic Freestyle aortic bioprosthesis, a stentless design analogous to an aortic allograft, has zero-pressure-fixed leaflets treated with an antimineralization agent, and has been shown to have benefits of superior effective orifice area, excellent flow characteristics and durability. To evaluate the early results for its efficacy in view of post-operative performance. The valve was implanted using the cylinder method, with subcoronary, root-inclusion techniques or full root techniques. No patients experienced any significant valvular regurgitation on echocardiography. The post-operative data of EDVI, ESVI and LVPWD decreased significantly as compared with the pre-operative data while ejection fraction remained unchanged. The average peak pressure gradient was 16.5 mmHg, and the average effective orifice area was 2.45 cm2. In conclusion, Freestyle stentless aortic bioprosthesis showed excellent hemodynamic function. It seems to be suited for the older patient with a small aortic annulus.     

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.     

Perceval S aortic valve implantation in mini-invasive surgery: the simple sutureless solution

The Perceval S bioprosthesis (21 and 23?mm) was approved for clinical use in December 2010 and it is now routinely used. This bioprosthesis is suggested for the treatment of patients undergoing minimally-invasive surgery for reasons of safety and reduction in implantation time. Here we describe the use of the Perceval bioprosthesis in patients undergoing minimally invasive cardiac surgery.     

Early degeneration of two different tricuspid bioprostheses in restrictive cardiomyopathy

Early degeneration of tricuspid bioprostheses is a rare, but extremely serious, complication. Several mechanisms have been described, both for surgically implanted and transcatheter bioprosthesis. We report a case of early degeneration of tricuspid porcine bioprosthesis and a subsequent transcatheter valve-in-valve bovine prosthesis due to severe fibrosis with leaflet retraction in a patient with restrictive cardiomyopathy who finally underwent orthotopic heart transplantation.     

Influence of Pulmonic Position on Durability of Bioprosthetic Heart Valves

Background. The insertion of bioprosthetic valves into the pulmonic position is not performed commonly because of uncertainty concerning the necessity and durability of such valves.

Methods. We reviewed the long-term outcome of 10 patients who underwent pulmonary valve replacement with bioprostheses between March 1985 and March 1997. A Carpentier-Edwards supraannular bioprosthesis was used in 7 patients, a Hancock II bioprosthesis was used in 2 patients, and a Carpentier-Edwards pericardial bioprosthesis was used in 1 patient. The mean patient age at the time of pulmonary valve replacement was 38.9 ± 16.3 years (range, 15 to 63 years). The diagnoses were pulmonary valvular regurgitation after corrective surgery for tetralogy of Fallot in 7 patients, right ventricular outflow tract stenosis and absent right pulmonary artery combined with a double-outlet right ventricle in 1 patient, pulmonary valvular regurgitation with pulmonary artery dilatation in 1 patient, and aortic valve stenosis treated with our modification of the Ross procedure using a pulmonary bioprosthesis in 1 patient. Survivors were followed up for a mean of 5 years and 5 months.

Results. One patient underwent reoperation because of infective endocarditis of the bioprosthesis. No bioprosthetic valve dysfunction has been observed on Doppler echocardiography during a maximum follow-up period of 12.2 years, except in the patient who underwent replacement at 15 years of age.

Conclusions. Bioprostheses in the pulmonic position are durable in adult patients because they face a minimal hemodynamic load, but they may undergo early leaflet degeneration in younger patients.     

Tricuspid transcatheter valve-in-valve: an alternative for high-risk patients

Tricuspid valve disease is not uncommon. Some patients with tricuspid valve disease require tricuspid replacement with bioprosthesis and, over time, may require re-interventions. Transcatheter tricuspid valve-in-valve approach has emerged as an alternative to treat dysfunctional bioprosthesis. In this article, we report a case of a patient with four previous cardiac interventions presenting with tricuspid bioprosthesis dysfunction. The patient was treated with the transcatheter transatrial tricuspid valve-in-valve procedure. The procedure was successful with no residual leakage and a non-significant mean gradient. The patient recovered well and was discharged in 1 week. The procedure is a feasible alternative for high-risk patients. Selection and postoperative care are crucial for the outcome.     

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.