Totally biological composite aortic stentless valved conduit for aortic root replacement: 10-year experience

Journal of Cardiothoracic Surgery Totally biological composite aortic stentless valved conduit for aortic root replacement: 10-year experience Manuel Galianes 0 2 Ayo Meduoye 0 Ignacio Ferreira 1 Andrzej Sosnowski 0 0 Department of Cardiac Surgery, The Glenfield Hospital , Leicester , UK 1 Department of Cardiology, Reparative Therapy of the Heart, Area del Cor (ACOR) and Research Institute, University Hospital Vall d'Hebron, Universitat Autonoma de Barcelona , Barcelona , Spain 2 Department of Cardiac Surgery, Research Institute, University Hospital Vall d'Hebron, Universitat Autonoma de Barcelona , Barcelona , Spain Objectives: To retrospectively analyze the clinical outcome of a totally biological composite stentless aortic valved conduit (No-React BioConduit) implanted using the Bentall procedure over ten years in a single centre. Methods: Between 27/10/99 and 19/01/08, the No-React BioConduit composite graft was implanted in 67 patients. Data on these patients were collected from the in-hospital database, from patient notes and from questionnaires. A cohort of patients had 2D-echocardiogram with an average of 4.3 0.45 years post-operatively to evaluate valve function, calcification, and the diameter of the conduit. Results: Implantation in 67 patients represented a follow-up of 371.3 patient-year. Males were 60% of the operated population, with a mean age of 67.9 1.3 years (range 34.1-83.8 years), 21 of them below the age of 65. After a mean follow-up of 7.1 0.3 years (range of 2.2-10.5 years), more than 50% of the survivors were in NYHA I/II and more than 60% of the survivors were angina-free (CCS 0). The overall 10-year survival following replacement of the aortic valve and root was 51%. During this period, 88% of patients were free from valved-conduit related complications leading to mortality. Post-operative echocardiography studies showed no evidence of stenosis, dilatation, calcification or thrombosis. Importantly, during the 10-year follow-up period no failures of the valved conduit were reported, suggesting that the tissue of the conduit does not structurally change (histology of one explant showed normal cusp and conduit). Conclusions: The No-React BioConduit composite stentless aortic valved conduit provides excellent long-term clinical results for aortic root replacement with few prosthesis-related complications in the first post-operative decade. aorta and aortic valve disease; aortic valved conduit; aortic root replacement; Bentall?'?s operation; BioConduit; detoxified tissue; homografts; autografts - Introduction The aortic root replacement by the Bentalls procedure, described in 1968 [1], has been refined over time [2-4] and still represents the preferred treatment for patients with ascending aortic aneurysm and aortic valve disease in whom the Davids or Yacoubs operation cannot be performed. Initially, the use of composite grafts with mostly mechanical valves was considered a good treatment, however the 10-year results are less than desirable [2,5]. This is mostly because of the complications of anticoagulation and low, but consistent, rates of infection that require removal of the Dacron graft, which carries a high rate of mortality [4,6]. In the presence of infection, replacement of the synthetic graft with a biological conduit is needed [6,7]. Therefore, there is a need to determine the ideal valved conduit, preferably totally biological, not requiring anticoagulation, and durable for all patient ages. Among the biological conduits, allografts (also known as homografts) and pulmonary autografts (Ross procedure) have been considered for aortic root replacement, but the former are not always available and the latter is not always possible. However, short-term follow-up studies have clearly shown that, when compared to the composite mechanical valve conduits, allografts and pulmonary autografts have advantages only early after implantation [5], because allografts seems to have agerelated limited durability [8] and after eight years follow-up the pulmonary autografts freedom from moderate or severe regurgitation is below 75%, and freedom from dilatation is between 10-15% [9]. Furthermore, Pasquali et al. have shown that pulmonary autografts in the aortic position dilate for up to 60% of patients at 6 years follow-up [10]. Such a high rate of dilatation would lead to progressive rates of aortic valve dysfunction, a process that appears to start only after 3 years [9-11]. The causes of these detrimental changes are not fully elucidated but Schoof et al. [11] performing histological analysis on explanted pulmonary autografts from the Ross procedure demonstrated that the elastic tissue of the autograft had been slowly substituted with fibrous material, including both the conduit wall and the valve cusps, a degeneration considered as a negative remodelling process. It is clear that biological valved conduits alternative to allografts and pulmonary autografts are much needed, having in mind that the ideal bioconduit should require no anticoagulation, can be implanted in patients of all ages, and should have no structural changes over the years. In addition, the ideal conduit should resist infection. The No-React BioConduit is a valved conduit made from bovine pericardium made with the aim to resist foreign body reaction and degeneration without needing anticoagulation. Previous experimental animal studies have shown that No-React tissue causes no foreign body reaction, leading to a resistance to calcification and degeneration [12]. Further studies using No-React tissue as a patch for the Norwood procedure caused no anti-HLA antibodies whereas allografts induced the production of antibodies [13]. Indeed, clinical studies with No-React valves, receiving an identical treatment to the No-React BioConduit, have shown a high resistance to infection [14,15]. However, a recent report has warned on the possibility that this valved conduit may undergo degeneration [16]. For a number of years, the No-React BioConduit has been used in our institution in patients with low life expectancy and advanced disease of the aortic valve and root in whom the implantation of other valved conduits was not advisable or possible. Therefore, in this study, we have investigated the long-term clinical results with the Bentall procedure using the No-React BioConduit (BioIntegral Surgical, Inc., Canada, formerly manufactured by Shelhigh) over a 10-year period in high risk patients in a single centre. Patients and Methods Between October 1999 and January 2008, 67 patients with significant aortic valve and root pathology received a No-React BioConduit. The preoperative characteristics of the study population are shown in Table 1. Of them, 40 were males (60%) and 27 females (40%) with a mean age of 67.9 1.3 years (range 34.1-83.8 years), with 21 being below the age of 65. This also shows that approximately 40% of the patients suffered from angina Table 1 Patients characteristic (...truncated)