First 102 Patients With the Biovalsalva Conduit for Aortic Root Replacement

Contemporary outcomes of composite aortic root replacement in elderly patients

Figure 4.

OBJECTIVES

We investigated the clinical and haemodynamic outcomes in elderly patients undergoing composite aortic root replacement.

METHODS

Between 2005 and 2017, 135 patients underwent aortic root surgery at our hospital. Of these 135 patients, 47 patients aged ≥65 years were included in this study. Pathologies included aneurysms in 31, chronic aortic dissection in 6, acute aortic dissection in 4 and other causes in 6 patients. A bioprosthesis was used in 27 and a mechanical valve in 20 patients. The mean age was 71.0 ± 4.3 years. The mean follow-up period was 61 ± 35 months. Follow-up echocardiographic data (average 48 months after surgery) were collected in 35 patients (74%).

RESULTS

The in-hospital mortality rate was 2.1% (1 patient). Seven late deaths occurred during follow-up. The 1-, 5- and 8-year overall survival was 93.6%, 82.9% and 82.9%, respectively. Infective endocarditis, Marfan syndrome and diabetes were independent predictors of poorer survival. During the follow-up, thromboembolism occurred in 1 patient, major bleeding events in 5 patients, or proximal reoperation for prosthetic valve endocarditis in 1 patient. The type of valve, mechanical or biological valve, did not affect late mortality and morbidity. Follow-up echocardiography revealed significantly improved left ventricular ejection fraction compared with that at discharge.

CONCLUSIONS

Composite aortic root replacement provided satisfactory midterm outcomes in patients aged ≥65 years. Further studies with a longer follow-up are warranted to evaluate late valve-related events.

Impact of sinuses of Valsalva on prosthesis durability in patients undergoing ascending aorta and aortic valve replacement with Carpentier-Edwards bioprosthesis: a propensity score-based study

OBJECTIVES

The effect of sinuses of Valsalva on aortic bioprosthesis durability has not been investigated so far. The aim of this study was to compare durability of the Carpentier-Edwards aortic bioprosthesis in patients undergoing aortic valve and ascending aorta replacement as a composite bioconduit (Group A, case group) versus patients undergoing separate replacement of the aortic valve and ascending aorta, with preservation of the aortic root (Group B, control group), between January 2000 and January 2014.

METHODS

Records of Group A (n = 133) and Group B (n = 162) patients were retrospectively reviewed. End-points were evaluated among groups in three ways: before and after propensity score 1:1 matching (Group A, n = 94; Group B, n = 94 patients) and after patient stratification through quintiles of propensity scores.

RESULTS

There was no difference among groups regarding mean and maximal trans-prosthetic pressure gradients at discharge (P = 0.07 and 0.45, respectively). Maximal trans-prosthetic gradients were lower in Group A patients at last control (P = 0.03). Structural valve deterioration (SVD) was due to prosthesis regurgitation (Group A, n = 5; Group B, n = 1), stenosis (Group A, n = 2; Group B, n = 5) or combined (Group A, n = 4; Group B, n = 2). After a mean follow-up of 68 ± 42 months, there was no difference among groups, at 5 and 12 years, regarding mortality, freedom from SVD, from redo aortic valve replacement for SVD and cardiac redo of any type, before and after matching and after stratification according to quintiles of propensity scores.

CONCLUSIONS

Within the 12-year follow-up, the absence of the sinuses of Valsalva seems to have no influence on durability of Carpentier Edwards aortic bioprosthesis. Longer follow-up may be warranted.

Assessment of Hemodynamic Conditions in the Aorta Following Root Replacement with Composite Valve-Conduit Graft

This paper presents the analysis of detailed hemodynamics in the aortas of four patients following replacement with a composite bio-prosthetic valve-conduit. Magnetic resonance image-based computational models were set up for each patient with boundary conditions comprising subject-specific three-dimensional inflow velocity profiles at the aortic root and central pressure waveform at the model outlet. Two normal subjects were also included for comparison. The purpose of the study was to investigate the effects of the valve-conduit on flow in the proximal and distal aorta. The results suggested that following the composite valve-conduit implantation, the vortical flow structure and hemodynamic parameters in the aorta were altered, with slightly reduced helical flow index, elevated wall shear stress and higher non-uniformity in wall shear compared to normal aortas. Inter-individual analysis revealed different hemodynamic conditions among the patients depending on the conduit configuration in the ascending aorta, which is a key factor in determining post-operative aortic flow. Introducing a natural curvature in the conduit to create a smooth transition between the conduit and native aorta may help prevent the occurrence of retrograde and recirculating flow in the aortic arch, which is particularly important when a large portion or the entire ascending aorta needs to be replaced.

In-vivo assessment of the morphology and hemodynamic functions of the BioValsalva™ composite valve-conduit graft using cardiac magnetic resonance imaging and computational modelling technology

BACKGROUND

The evaluation of any new cardiac valvular prosthesis should go beyond the classical morbidity and mortality rates and involve hemodynamic assessment. As a proof of concept, the objective of this study was to characterise for the first time the hemodynamics and the blood flow profiles at the aortic root in patients implanted with BioValsalva™ composite valve-conduit using comprehensive MRI and computer technologies.

METHODS

Four male patients implanted with BioValsalva™ and 2 age-matched normal controls (NC) underwent cardiac magnetic resonance imaging (MRI). Phase-contrast imaging with velocity-mapping in 3 orthogonal directions was performed at the level of the aortic root and descending thoracic aorta. Computational fluid dynamic (CFD) simulations were performed for all the subjects with patient-specific flow information derived from phase-contrast MR data.

RESULTS

The maximum and mean flow rates throughout the cardiac cycle at the aortic root level were very comparable between NC and BioValsalva™ patients (541 ± 199 vs. 567 ± 75 ml/s) and (95 ± 46 vs. 96 ± 10 ml/s), respectively. The maximum velocity (cm/s) was higher in patients (314 ± 49 vs. 223 ± 20; P = 0.06) due to relatively smaller effective orifice area (EOA), 2.99 ± 0.47 vs. 4.40 ± 0.24 cm2 (P = 0.06), however, the BioValsalva™ EOA was comparable to other reported prosthesis. The cross-sectional area and maximum diameter at the root were comparable between the two groups. BioValsalva™ conduit was stiffer than the native aortic wall, compliance (mm2 • mmHg(-1) • 10(-3)) values were (12.6 ± 4.2 vs 25.3 ± 0.4.; P = 0.06). The maximum time-averaged wall shear stress (Pa), at the ascending aorta was equivalent between the two groups, 17.17 ± 2.7 (NC) vs. 17.33 ± 4.7 (BioValsalva™ ). Flow streamlines at the root and ascending aorta were also similar between the two groups apart from a degree of helical flow that occurs at the outer curvature at the angle developed near the suture line.

CONCLUSIONS

BioValsalva™ composite valve-conduit prosthesis is potentially comparable to native aortic root in structural design and in many hemodynamic parameters, although it is stiffer. Surgeons should pay more attention to the surgical technique to maximise the reestablishment of normal smooth aortic curvature geometry to prevent unfavourable flow characteristics.

The Bentall procedure with a biological valved conduit: substitute options and techniques

As originally described by Bentall and De Bono, aortic root replacement with reimplantation of the coronary arteries using a composite valved conduit represents the gold standard intervention in patients with aneurysmal disease or dissection involving the aortic root. Over the last decade, the number of Bentall procedures performed using biological valved conduit has dramatically expanded mainly due to the increased incidence of aortic disease in the aging population. Here, we sought to describe the commercially available biological composite grafts and the techniques that, to the best of our knowledge, are most frequently used in this setting.

Chronic dissection and aneurysmal dilatation of a BioValsalva conduit

The BioValsalva (Vascutek Terumo, Renfrewshire, Scotland, UK) conduit is the first commercially available prefabricated bioprosthetic aortic valved conduit. We present a case of chronic dissection of a BioValsalva valved conduit presenting as a 7.5-cm aortic root aneurysm 1 year after a Bentall operation. Intraoperatively, the conduit was found to have dissected from the annulus upward, and the coronary buttons were avulsed from the inner layers while remaining attached to the outer layer. Both the outer layer and the coronary buttons were grossly dilatated.