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Tirone E. David - One of the best experts on this subject based on the ideXlab platform.

  • Aortic Valve sparing in different Aortic Valve and Aortic root conditions
    Journal of the American College of Cardiology, 2016
    Co-Authors: Tirone E. David
    Abstract:

    The development of Aortic Valve-sparing operations (reimplantation of the Aortic Valve and remodeling of the Aortic root) expanded the surgical armamentarium for treating patients with Aortic root dilation caused by a variety of disorders. Young adults with Aortic root aneurysms associated with genetic syndromes are ideal candidates for reimplantation of the Aortic Valve, and the long-term results have been excellent. Incompetent bicuspid Aortic Valves with dilated Aortic annuli are also satisfactorily treated with the same type of operation. Older patients with ascending Aortic aneurysm and Aortic insufficiency secondary to dilated sinotubular junction and a normal Aortic annulus can be treated with remodeling of the Aortic root or with reimplantation of the Aortic Valve. The first procedure is simpler, and both procedures are likely equally effective. As with any heart Valve-preserving procedure, patient selection and surgical expertise are keys to successful and durable repairs.

  • Aortic Valve repair and Aortic Valve–sparing operations
    The Journal of thoracic and cardiovascular surgery, 2014
    Co-Authors: Tirone E. David
    Abstract:

    Attempts to correct Aortic insufficiency by means of Aortic Valve repair started soon after the advent of open-chest cardiac surgery. Correction of cusp prolapse was performed by suturing the free margins of 2 cusps from the commissures to the central portion or by excising the noncoronary Aortic cusp and sinus, transforming a tricuspid into a bicuspid Aortic Valve. In the early days of cardiac surgery, Aortic cusp extension with fascia lata was also done to correct Aortic insufficiency. The lack of adequate imaging of the Aortic Valve limited the application of these techniques and the development of new ones. Echocardiography changed all that and had a dramatic effect on our ability to examine the Aortic Valve, select patients for Aortic Valve repair, and assess Valve function intraoperatively and postoperatively. The Aortic Valve is better described as a unit, the Aortic root, which is made of various components. The Aortic cusps are certainly the most important, but the aortoventricular junction, the Aortic sinuses, and the sinotubular junction also play a role in how the cusps open without obstruction during systole or and close without leakage during diastole. The phrase ‘‘form follows function’’ is certainly applicable to the Aortic root, and although we have learned a great deal regarding how the various components of the Aortic root interact, there is still a lot to be learned. As a student of the Aortic root, I have been surprised by the variability in physical appearance of Aortic root in individuals with normally functioning Aortic Valve as well as before and after operations that preserve the native Aortic cusps. Years ago, Feindel and I coined the term Aortic Valve– sparing operations to describe conservative procedures on the Aortic Valve in patients with Aortic root or ascending Aortic aneurysms. A few years later, we classified Aortic Valve–sparing operations into 2 subgroups, Aortic Valve reimplantation and Aortic root remodeling. This new surgical nomenclature was an attempt to define the various types of operative procedures that we used to preserve the Aortic

  • Surgical treatment of Aortic Valve disease
    Nature Reviews Cardiology, 2013
    Co-Authors: Tirone E. David
    Abstract:

    The development of intraoperative transoesophageal echocardiography together with improved understanding of the functional anatomy of the Aortic Valve have allowed the design of several new conservative procedures, such as Aortic Valve-sparing operations, to treat patients with Aortic root aneurysms or Aortic insufficiency. The long-term results of these procedures have been excellent, and >90% of patients are free from reoperation on the Aortic Valve 10–15 years after surgery. Incompetent bicuspid Aortic Valves can also be repaired if the cusps are pliable and without calcification. Nevertheless, most patients with Aortic Valve disease, particularly those with Aortic stenosis, need Aortic Valve replacement. Matching a patient to the type and size of prosthetic Aortic Valve is difficult, because of the limited durability of bioprosthetic Valves and the need for lifelong anticoagulation with mechanical Valves. Prosthesis–patient mismatch might not affect survival in most patients, but is a determinant of prognosis in patients with impaired ventricular function. Young adults with Aortic stenosis, particularly women during childbearing years, can be treated with the Ross procedure. Finally, poor candidates for surgery who have Aortic stenosis can now be treated with catheter-based Aortic Valve implantation but, in this article, the current status of Aortic Valve surgery is reviewed. Aortic root aneurysms caused by an inherited condition, and dilatation of the ascending aorta associated with a bicuspid Aortic Valve, require surgical repair when the Aortic diameter nears 50 mm The native Aortic Valve is often preserved during surgery for Aortic root aneurysms caused by an inherited condition Matching a patient to the type and size of a prosthetic heart Valve is challenging in Aortic Valve replacement Bioprosthetic Aortic Valves provide better clinical outcomes than mechanical Valves in older patients (aged ≥65 years) Tirone David expertly reviews the surgical repair and replacement of the Aortic Valve. Patient selection for Aortic Valve-sparing operations, bioprosthetic or mechanical Valve insertion, pulmonary autograft, Aortic Valve homograft, and Aortic root replacement is discussed. Finally, the author assesses the long-term clinical outcomes of these procedures.

  • Aortic Valve haemodynamics after Aortic Valve-sparing operations.
    European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, 2011
    Co-Authors: Tirone E. David
    Abstract:

    Basically, there are two basic types of Aortic Valve-sparing operations: remodelling of the Aortic root and reimplantation of the Aortic Valve [1]. After more than 2 decades of experience with these operations, we have concluded that they are not competitive procedures, but provide excellent long-term results when correctly matched to the Aortic root pathology [2, 3]. Remodelling of the Aortic root is physiologically superior to reimplantation of the Aortic Valve [4], but it does not address the problem of annular dilatation that often occurs in young patients with inherited Aortic root aneurysms. As the dilatation of the Aortic annulus can appear after the remodelling procedure, we believe that young patients are better served with reimplantation of the Aortic Valve. Remodelling of the Aortic root is a good alternative to reimplantation of the Aortic Valve in older patients with normal Aortic annulus and it is easier to perform. Regardless of the type of Aortic Valve sparing, restoration of normal Aortic cusps geometry is the most important technical aspect of these operations. A key element for long-term success is the level and area of cusps coaptation. At the end of the procedure, the coaptation of the cusps must be inside the Aortic root and a few millimetres above the level of the nadir of the Aortic annulus, and the cusps coaptation length must be at least 4 mm. Remodelling of the Aortic root has practically no adverse effect on systolic performance of the Aortic Valve because it does not change the diameter of the Aortic annulus and has minimal effect on the movements of the Aortic annulus during the cardiac cycle. In addition, the velocity of opening and closure of the cusps is only slightly increased [4]. Reimplantation of the Aortic Valve into a Dacron graft (straight tube or the Valsalva Graft by Vascutek Ltd, Renfreshsire, Scotland) alters every component of the Aortic Valve: the annulus, the cusps, the sinotubular junction and the Aortic sinuses. The Aortic annulus becomes rigid once sutured inside the Dacron graft. The degree of narrowing of the annulus will vary with the size of the graft used and the technique used for fixation of the annulus. The sinotubular junction is reduced and the Aortic sinuses completely abolished when a straight tubular Dacron graft is used. The velocity of opening and closure of the Aortic cusps is greatly increased in this operation [4], but it can be decreased by creating neo-Aortic sinuses [5] or by using the Valsalva Graft [6]. Fixation of the Aortic annulus and reduction of its diameter will invariably increase the impedance of blood flow to some degree that is not seen after remodelling of the Aortic root. Actually, there is a case report of Aortic stenosis after the reimplantation procedure because of purse stringing of the Aortic annulus during its fixation in the tubular Dacron graft [7]. This is caused by a technical error that can be prevented by using grafts of adequate size and carefully tying the sub-annular sutures [2, 3]. In this issue of this journal, D’Ancona et al. [8] from Palermo, Italy, published a study that examined the haemodynamics of the Aortic Valve after the reimplantation technique in 17 patients and compared it with that of 18 matched controls. Aortic Valve function was assessed by echocardiography at rest and during maximal exercise. Area of the left ventricular outflow tract and flow velocities were measured and the derivatives were calculated. Aortic Valve area index at rest was 1.1 ± 0.2 cm/m in the reimplantation group and 1.5 ± 0.2 cm/m in the control group (P = 0.0001), and during maximal exercise it increased significantly to 1.4 ± 0.2 in the reimplantation group and to 1.7 ± 0.2 in the control group. There were no differences between the groups in peak and mean transvalvular gradients at rest and during exercise. Most patients in the reimplantation group had mild Aortic insufficiency and the degree of Valve dysfunction did not change during exercise. This is probably the first published study on systolic performance of the Aortic Valve after the reimplantation procedure into a straight Dacron tube in comparison with normal matched controls. Expectedly, the mean effective Aortic Valve orifice index after reimplantation of the Aortic Valve was smaller than that of matched controls, but the systolic performance was excellent and the Aortic Valve orifice increased in size during exercise. The size of the graft used for reimplantation certainly affects the Aortic Valve area. In D’Ancona’s study [8], the selection of the graft size was based on the diameter of the sinotubular junction, and grafts 26, 28 and 30 mm in diameter were used. The method used by these investigators to estimate the size of the graft is similar to our method, but we use grafts of >4–6 mm to create neo-Aortic sinuses by placing darts in the graft in the spaces in between commissures where the Valve is reimplanted [2, 3].

  • Aortic Valve sparing operations.
    Seminars in thoracic and cardiovascular surgery, 2011
    Co-Authors: Tirone E. David
    Abstract:

    Aortic Valve sparing operations were developed to preserve the Aortic Valve in patients with ascending Aortic aneurysm and Aortic insufficiency or patients with Aortic root aneurysm. There are 2 types of Aortic Valve sparing operations, remodeling of the Aortic root and reimplantation of the Aortic Valve. The author believes that remodeling of the Aortic root is more appropriate for older patients with ascending Aortic aneurysm, dilated Aortic sinuses, and normal Aortic annulus, whereas reimplantation of the Aortic Valve is more appropriate for young patients with Aortic root aneurysm in whom dilation of the Aortic annulus is commonly associated. Although remodeling of the Aortic root has been extensively used in patients with Aortic root aneurysm, the long-term results are somewhat inferior to reimplantation in most series. The late results of Aortic Valve sparing operations have been excellent, and these operations have become an important addition to the surgical armamentarium to treat patients with proximal Aortic aneurysms.

Ron Ree - One of the best experts on this subject based on the ideXlab platform.

  • Transcatheter Aortic Valve Replacement
    Anesthesiology Clinics, 2008
    Co-Authors: Anson Cheung, Ron Ree
    Abstract:

    Aortic stenosis is one of the most common Valve pathologies found in adults. Aortic Valve replacement via a sternotomy and cardiopulmonary bypass is the treatment of choice for patients with symptomatic Aortic stenosis with very acceptable risk. However, patients with advanced age and multiple comorbidities carry significant operative risk; operative mortality as high as 25% was reported by many groups. Many of these patients are deemed nonsurgical for conventional Aortic Valve replacement by their cardiologists and surgeons. Novel surgical technique and Valve technology offers an alternative treatment for Aortic Valve stenosis. Endovascular transcatheter Aortic Valve replacement is an emerging and promising technique, and may lower the risk in this subset of difficult patients. © 2008 Elsevier Inc. All rights reserved.

  • Transcatheter Aortic Valve Replacement
    Anesthesiology clinics, 2008
    Co-Authors: Anson Cheung, Ron Ree
    Abstract:

    Aortic stenosis is one of the most common Valve pathologies found in adults. Aortic Valve replacement via a sternotomy and cardiopulmonary bypass is the treatment of choice for patients with symptomatic Aortic stenosis with very acceptable risk. However, patients with advanced age and multiple comorbidities carry significant operative risk; operative mortality as high as 25% was reported by many groups. Many of these patients are deemed nonsurgical for conventional Aortic Valve replacement by their cardiologists and surgeons. Novel surgical technique and Valve technology offers an alternative treatment for Aortic Valve stenosis. Endovascular transcatheter Aortic Valve replacement is an emerging and promising technique, and may lower the risk in this subset of difficult patients.

Giovanni Esposito - One of the best experts on this subject based on the ideXlab platform.

Michael C. Fishbein - One of the best experts on this subject based on the ideXlab platform.

  • Pathology of the Aortic Valve: Aortic Valve Stenosis/Aortic Regurgitation
    Current Cardiology Reports, 2019
    Co-Authors: Gregory A. Fishbein, Michael C. Fishbein
    Abstract:

    Purpose of Review This discussion is intended to review the anatomy and pathology of the Aortic Valve and Aortic root region, and to provide a basis for the understanding of and treatment of the important life-threatening diseases that affect the Aortic Valve. Recent Findings The most exciting recent finding is that less invasive methods are being developed to treat diseases of the Aortic Valve. There are no medical cures for Aortic Valve diseases. Until recently, open-heart surgery was the only effective method of treatment. Now percutaneous approaches to implant bioprosthetic Valves into failed native or previously implanted bioprosthetic Valves are being developed and utilized. A genetic basis for many of the diseases that affect the Aortic Valve is being discovered that also should lead to innovative approaches to perhaps prevent these disease. Sequencing of ribosomal RNA is assisting in identifying organisms causing endocarditis, leading to more effective antimicrobial therapy. Summary There is exciting, expanding, therapeutic innovation in the treatment of Aortic Valve disease.

  • Pathology of the Aortic Valve: Aortic Valve Stenosis/Aortic Regurgitation.
    Current cardiology reports, 2019
    Co-Authors: Gregory A. Fishbein, Michael C. Fishbein
    Abstract:

    Purpose of Review This discussion is intended to review the anatomy and pathology of the Aortic Valve and Aortic root region, and to provide a basis for the understanding of and treatment of the important life-threatening diseases that affect the Aortic Valve.

Patrick Donzeaugouge - One of the best experts on this subject based on the ideXlab platform.