Functional Aortic Annulus Research Articles

Functional aortic annulus remodelling-revisited.

Functional aortic annulus remodelling-revisited.

Comparison of aortic valve repair techniques with single and double ring annuloplasties.

For patients with isolated aortic regurgitation, a double sub- and supravalvular annuloplasty has been shown to reduce recurrent aortic regurgitation after aortic valve repair compared with a single subvalvular annuloplasty. The objective of this study was to compare the geometrical and dynamic properties of a single- and double ring annuloplasty in an in vitro model. Eighteen aortic roots from 80 kg pigs were randomized into a control, single ring, and double ring group. Experiments were conducted in a pulsatile in vitro model. Hydrodynamics, radial force measurements at annular and sinotubular level, and 2D echographic imaging were obtained. Both the single- and double ring annuloplasty downsized the aortic annulus and sinotubular junction significantly, and increased the coaptation height. The double ring annuloplasty showed an additional significant increase in coaptation height compared with the single ring (8.5 (0.9) mm to 9.8 (0.8) mm, p < 0.01). The single ring annuloplasty reduced radial forces at both levels, whereas the double ring annuloplasty showed the greatest force reduction of the sinotubular junction. By treating the whole functional aortic annulus, encompassing both the aortic annulus and the sinotubular junction, a greater force reduction is observed. A subvalvular annuloplasty alone is efficient in reducing aortic annulus diameter and increasing coaptation height, however, by treating the sinotubular junction as well, an additional effect is observed on coaptation height, creating a more efficient stabilization. Reduction of annular force-distensibility ratio with the double ring annuloplasty compared with the native controls indicate a sustained stabilizing effect.

Functional and pathomorphological anatomy of the aortic valve and root for aortic valve sparing surgery in tricuspid and bicuspid aortic valves.

The aortic valve (AV) is a three-dimensional structure, with leaflets that are suspended within the functional aortic annulus (FAA). These structures (AV and FAA) are therefore intrinsically connected and disease of just one component can independently lead to AV dysfunction. Hence, AV dysfunction can occur in the setting of entirely normal valve leaflets. However, as these structures are functionally inter-connected, disease of one component can lead to abnormalities of the other over time. Thus, AV dysfunction is often multifactorial. Valve-sparing root procedures require an in-depth understanding of these inter-relationships, and herein we are providing a detailed account of some of the most pertinent anatomical relationships.

Abstract 14451: Mechanistic Classification and Outcomes of Isolated Aortic Regurgitation in a Contemporary Cohort of Patients

Introduction: Aortic valve regurgitation (AR) is due to leaflet disease and/or dilatation of the functional aortic annulus complex. Understanding the mechanism(s) of AR informs surgical planning of valve and aorta repair. In this study we aimed to examine the etiologies, mechanisms, and outcomes of isolated pure native severe AR in a contemporary consecutive cohort of patients. Methods: From our institutional echocardiography database, we identified all patients with native moderate-to-severe (3+) or severe (4+) AR between 2014-2019. Patients with infective endocarditis, aortic dissection, or other concomitant valve disease were excluded. AR was classified using the El-Khoury classification: Type I-normal leaflet motion (Ia = ascending aorta and sinotubular junction dilatation, Ib = aortic root dilation, Ic = aortic annular dilation), Type II-leaflet prolapse, and Type III-leaflet restriction. Valve anatomy and clinical outcomes were also extracted. Results: A total of 560 patients with at least moderate-to-severe (3+) AR were identified, 270 were excluded (92 patients for endocarditis, 152 patients for concomitant valvulopathy, 23 patients for acute aortic dissection, and 11 patients for other reasons), and 282 patients (77.3% male) were included. The most common mechanism was Type II (leaflet prolapse), idenfied in 98 (35%) patients. Multiple mechanisms of AR were identified in 164 (58%) patients. The most common combination was Type Ib (aortic root dilation) and Type II (leaflet prolapse) seen in 45 (27%) patients. Ninety-nine (35%) patients had a bicuspid aortic valve (BAV). Follow-up was available for 275 patients (98%) with a median duration of 4.7±2.4 years. Of the 158 (57%) patients who underwent surgical intervention, valve repair was performed in 77 patients (49%) and valve replacement in 80 (51%) patients. Valve intervention was more common in women (70%) than in men (54%). Conclusion: In a large contemporary cohort of patients with at least moderate to severe (3+) isolated pure native AR, Type II (leaflet prolapse) was the most common mechanism, however multiple mechanisms are present in most AR patients. Aortic valve repair now accounts for almost half of the surgical interventions for isolated AR in our center.

MECHANISTIC CLASSIFICATION AND OUTCOMES OF ISOLATED AORTIC REGURGITATION IN A CONTEMPORARY COHORT OF PATIENTS

MECHANISTIC CLASSIFICATION AND OUTCOMES OF ISOLATED AORTIC REGURGITATION IN A CONTEMPORARY COHORT OF PATIENTS

Aortic Valve Repair Using HAART 300 Geometric Annuloplasty Ring: A Review and Echocardiographic Case Series

Aortic valve repair (AVr) aims to preserve the native aortic leaflets and restore normal valve function. In doing so, AVr is a more technically challenging approach than traditional aortic valve replacement. Some of the complexity of repair techniques can be attributed to the unique structure of the functional aortic annulus (FAA), which, unlike the well-defined mitral annulus, is comprised of virtual and functional components. Though stabilizing the ventriculo-aortic junction (VAJ), a component of the FAA, is considered beneficial for patients with chronic aortic insufficiency (AI), the ideal AVr technique remains a subject of much debate. The existing AVr techniques do not completely stabilize the VAJ which may increase susceptibility to recurrent AI due to VAJ dilation. An emerging new technique showing promise for the treatment of both isolated and complex AI is AVr using HAART 300TM geometric annuloplasty ring (GAR). The GAR is implanted below the valve leaflets in the left ventricular outflow tract (LVOT), providing stability and creating a neo-annulus. As with other AVr subtypes, this procedure has a learning curve. There are unique surgical and echocardiographic aspects of AVr with GAR, including the appearance of the LVOT, the aortic valve leaflets, and their motion which cardiac anesthesiologists and echocardiographers must be familiar with. In this work, using an eight-patient echocardiographic case series, we provide an overview of this novel AVr technique, including some unique aspects of device sizing, patient selection, expected post-repair echocardiographic features, and a review of outcomes data.

The art of aortic valve repair

The art of aortic valve repair

Altered stresses and dynamics after single and double annuloplasty ring for aortic valve repair.

OBJECTIVESAortic valve repair procedures for the treatment of isolated aortic valve insufficiency may be improved by stabilizing the functional aortic annulus using a double annuloplasty ring at the aortic annulus and sinotubular junction (STJ). The objective of this study was to compare the geometrical changes and aortic root stress distribution when using a single subvalvular ring and a double sub- and supravalvular ring in vivo.METHODSBoth the single- and double-ring procedures were performed successively in nine 80-kg pigs. Measurements were performed intraoperatively using sonomicrometry crystals in the aortic root to evaluate geometrical changes and annular and STJ force transducers measuring the segmental radial stress distribution.RESULTSThe total force in the STJ was significantly reduced after the double-ring procedure from 1.7 ± 0.6 to 0.04 ± 1.1 N (P = 0.001). The double-ring procedure significantly reduced the STJ area from 234.8 ± 37.6 to 147.5 ± 31.8 mm2 (P = 0.001) and expansibility from 17 ± 6% to 8 ± 3% (P = 0.001). With the single-ring procedure, the STJ shape was circular but became more oval with the double-ring procedure. The double-ring procedure did not affect stress distribution or geometry in the aortic annulus.CONCLUSIONSThe double-ring procedure stabilized the whole aortic root by reducing radial stress distribution in the STJ more efficiently than the single-ring procedure. Both area and expansibility were reduced with the double-ring procedure. These results confirm the importance of addressing the entire functional aortic annulus for optimal aortic valve repair procedures.

Deep circumferential annuloplasty as an adjunct to repair regurgitant bicuspid aortic valves with a dilated annulus

BackgroundFailure to address the functional aortic annulus during bicuspid aortic valve (BAV) repair has led to early repair failures. The pathology of regurgitant BAV involves annular dilatation, which is more pronounced anteriorly and deep toward the muscular interventricular septum. In this study, we assessed the results of BAV repair using a strategy of deep circumferential annular support involving the septum in patients with a dilated annulus (>26 mm) and moderate to severe aortic regurgitation (AR). MethodsBetween February 1999 and June 2015, 100 patients with regurgitant (≥2+) BAV and a dilated ventriculoaortic junction (VAJ) (≥26 mm) underwent repair with an adjunctive circumferential annuloplasty (reimplantation procedure or ring). External root dissection to accommodate the annuloplasty was carried deep onto the anterior aspect of the interventricular septum. Follow up was complete in 96 patients, with a median follow-up of 31 months and a total of 362 patient-years. Cox regression analysis was used to predict recurrence of AR. ResultsThe mean VAJ diameter was 30 ± 4 mm. Seventy-nine patients exhibited delayed prolapse of the anterior leaflet (conjoined right and left cusps in Siever type 1 or anterior cusp in Siever type 0), and 93 patients underwent reimplantation. In the entire study group, there were no in-hospital deaths, and only 1 patient had 2+ AR on discharge. There was 1 late noncardiac death. At 8 years, freedom from AR ≥2+ was 96.4% and freedom from reoperation was 96.8%. Higher preoperative AR grade, small graft size, and use of a ring were predictive of recurrent AR. ConclusionsRegurgitant BAVs with a dilated annulus display anterior cusp prolapse toward the septum. A deep circumferential annuloplasty may help maintain repair durability.

THE EFFECT OF VENTRICULO-AORTIC JUNCTION DILATATION ON AORTIC INSUFFICIENCY

The relationship between the Functional Aortic Annulus (FAA), consisting of the Ventriculo-aortic junction (VAJ) and the Sinotubular Junction (STJ) and aortic valve function is incompletely understood. We examined this relationship in a clinically relevant, high fidelity porcine model using a left heart simulator with 3-D echocardiography, hemodynamic assessment, and finite element modeling and by modifying aortic root geometry. Baseline hemodynamic measurements were performed on fresh porcine aortic roots (n=6) on a left heart simulator. VAJ dilatation was performed by remodeling the VAJ and sewing in an oversized Darcon tube graft (diameter=30mm). After dilated VAJ roots were analyzed, the sinotubular junction (STJ) was enlarged by making three veritical incisions at the STJ and patching these areas with three diamond (1cmX1cm) shaped pericardial patches. This created three dependent experimental groups: A) control, B) VAJ dilatation, and C) VAJ + STJ dilatation. Hemodynamic parameters included regurgitant fraction, regurgitant volume, and left ventricular work. 3-D echocardiography measured coaptation surface area. Finite element modeling using (n=10) patient aortic root geometry was performed to determine cusp stresses after each intervention. Baseline VAJ and STJ diameters were 24.3mm interquartile ranges [IQR= 23.3, 24.3] and 24.3mm [IQR=23.3, 25.1]. Following surgical remodeling the VAJ increased to 30mm [IQR=30, 30] and the STJ to 29.8mm [IQR=27.8, 29.8] (p = 0.02). All hemodynamic assessments were similar across groups with the exception of left ventricular work which significantly increased from baseline to VAJ + STJ dilatation (+12%; p=0.03). Regurgitation fraction increased from 4.3% [IQR=3.2, 5.5] at baseline to 14.5% [IQR=13.4, 17.3] (p=0.03) with VAJ dilatation and increased further with STJ dilatation to 18.5% [IQR=10.3, 27.8] (p=0.02). Coaptation surface area decreased from 1.75cm2 [IQR=1.65, 2.00] to 1.23cm2 [IQR=1.05, 1.37] (p=0.02) with VAJ dilatation and further with STJ dilatation to 1.09cm2 [IQR= 1.03, 1.14] (p=0.02 for control and VAJ intervention). An inverse linear relationship was found between VAJ diameter and coaptation surface area (R2=0.70; p=0.001; Figure 1). The combined leaflet stresses in the unaltered root was 530kPa[IQR=380,630] after 4mm diameter VAJ dilatation the stresses increased to 650 kPa [IQR=540,820] (p= 0.001). With an additional 4mm diameter STJ dilatation the leaflet stresses increased to 790 kPa [IQR=600, 1000] (p=0.005). VAJ dilatation produces a graded decrease in leaflet coaptation surface area along with increased leaflet stresses which is further amplified with STJ dilatation. This study provides new insights into mechanisms of annulus mediated AI and their responses to leaflet function and stresses.

The Sievers Classification of the Bicuspid Aortic Valve for the Perioperative Echocardiographer: The Importance of Valve Phenotype for Aortic Valve Repair in the Era of the Functional Aortic Annulus.

The Sievers Classification of the Bicuspid Aortic Valve for the Perioperative Echocardiographer: The Importance of Valve Phenotype for Aortic Valve Repair in the Era of the Functional Aortic Annulus.

Aortic cusp sizers to establish the functional classification of aortic insufficiency: algorithm and midterm outcome of operative repair

Wider adoption of aortic valve repair procedures is held up by the difficulty in recognizing the exact alterations that are responsible for aortic valve insufficiency. New aortic cusp sizers were developed to assist in aortic valve assessment in the operating theatre. Our objectives were to examine the efficacy of the aortic cusp sizers in establishing the functional classification of aortic valve insufficiency, and to report the midterm outcome in a group of patients who had undergone aortic valve repair guided by this device. A prospective clinical study was performed involving 33 consecutive patients (18 males, age range: 8-74 years) with severe aortic valve insufficiency (mean severity: 3.4 ± 0.5). The aortic cusp sizers were used as a template to identify existing cusp and root alterations. Consequently, the functional classification of aortic insufficiency was determined, and the appropriate techniques of aortic valve repair were implemented. Aortic valve repair was successful in all patients. Procedures performed were 37 functional aortic annulus corrections, 9 cusp free-edge plications, 2 cusp repairs with autologous pericardium, 9 replacements of the ascending aorta and 2 reimplantation procedures. At a mean follow-up time of 18.3 ± 13.7 months, 1 patient underwent aortic valve replacement for recurrent aortic valve regurgitation, while aortic valve function remained stable in 32 patients, with aortic insufficiency <1+ in 27 (84.4%) patients and 1-1.5 in 5 (15.6%) patients, and no significant gradients across the aortic valves. The aortic cusp sizers are valuable in establishing the functional classification of aortic insufficiency, and can guide implementation of aortic valve repair techniques successfully. This approach is analogous to that accredited for the success and wide adoption of mitral valve repair techniques, and is likely to assist in increasing the percentage of aortic valves that are repaired when compared with current practice.

A geometric approach to aortic root surgical anatomy.

The aim of this study was the analysis of the geometrical relationships between the different structures constituting the aortic root, with particular attention to interleaflet triangles, haemodynamic ventriculo-arterial junction and functional aortic annulus in normal subjects. Sixteen formol-fixed human hearts with normal aortic roots were studied. The aortic root was isolated, sectioned at the midpoint of the non-coronary sinus, spread apart and photographed by a high-resolution digital camera. After calibration and picture resizing, the software AutoCAD 2004 was used to identify and measure all the elements of the interleaflets triangles and of the aortic root that were objects of our analysis. Multiple comparisons were performed with one-way analysis of variance for continuous data and with Kruskal-Wallis analysis for non-continuous data. Linear regression and Pearson's product correlation were used to correlate root element dimensions when appropriate. Student's t-test was used to compare means for unpaired data. Heron's formula was applied to estimate the functional aortic annular diameters. The non coronary-left coronary interleaflets triangles were larger, followed by inter-coronary and right-non-coronary ones. The apical angle is <60° and its standard deviation can be considered an asymmetry index. The sinu-tubular junction was shown to be 10% larger than the virtual basal ring (VBR). The mathematical relationship between the haemodynamic ventriculo-arterial junction and the VBR calculated by linear regression and expressed in terms of the diameter was: haemodynamic ventriculo-arterial junction = 2.29 VBR (diameter) + 47. Conservative aortic surgery is based on a better understanding of aortic root anatomy and physiology. The relationships among its elements are of paramount importance during aortic valve repair/sparing procedures and they can be useful also in echocardiographic analysis and in computed tomography reconstruction.

Long-Term Hemodynamic Performance of the Aortic Valve After David I: An Echocardiographic Study

Despite optimal hemodynamics at rest, the performance of the aortic valve under stress conditions long after David I procedure is still debated. From 2001-2014, 73 patients underwent reimplantation with David I technique. Aortic valve function of 13 patients (age 61.2 ± 8.72) with a follow-up of at least 5 years (6.3 ± 0.9 years) was assessed at exercise echocardiographic stress test on a stationary cycle. Patients who had undergone concomitant procedure, with recurrent aortic insufficiency or mitral valve incompetence, were excluded. In all, 8 healthy volunteers served as controls. Transvalvular gradients progressively increased during the steps in both groups (P-within < 0.001), being higher in David patients (P-between < 0.001), but never reaching a clinical significance (David Peak gradient 23.8 ± 9.3 mmHg; Mean gradient 13.2 ± 5.1 mmHg). Effective orifice area (EOA) and EOA index did not change during the test in David patients, whereas Controls showed a progressive increase of functional valve area to a peak at 50 W (Controls EOA 4.0 ± 0.5 cm(2); EOA index 2.0 ± 0.3 cm(2)/m(2)). In conclusion, David I procedure ensures good hemodynamics during high-flow conditions at long-term follow-up. The reimplantation of the functional aortic annulus inside a rigid tube determines a paradoxical reduction of functional aortic valve area, secondary to the increased stroke volume, without any clinically relevant increase in transvalvular gradients. These data confirm the reliability of David I in the long term, even under physical stress conditions.

The functional aortic annulus in the 3D era: focus on transcatheter aortic valve replacement for the perioperative echocardiographer.

The functional aortic annulus represents a sound clinical framework for understanding the components of the aortic root complex. Recent three-dimensional imaging analysis has demonstrated that the aortic annulus frequently is elliptical rather than circular. Comprehensive three-dimensional quantification of this aortic annular geometry by transesophageal echocardiography and/or multidetector computed tomography is essential to guide precise prosthesis sizing in transcatheter aortic valve replacement to minimize paravalvular leak for optimal clinical outcome. Furthermore, three-dimensional transesophageal echocardiography accurately can quantify additional parameters of the functional aortic annulus such as coronary height for complete sizing profiles for all valve types in transcatheter aortic valve replacement. Although it is maturing rapidly as a clinical imaging modality, its role in transcatheter aortic valve replacement is seen best as complementary to multidetector computed tomography in a multidisciplinary heart team model.

The role of transesophageal echocardiography in aortic valve preserving procedures.

In selected cases of aortic regurgitation, aortic valve (AV) repair and AV sparing root reconstruction viable alternatives to aortic valve replacement. Repair and preservation of the native valve avoids the use of long-term anticoagulation, lowers the incidence of subsequent thromboembolic events and reduces the risk of endocarditis. Additionally repair has a low operative mortality with reasonable mid-term durability. The success and longer term durability of AVPP has improved with surgical experience. An understanding of the mechanism of the AR is integral to determining feasibility and success of an AVPP. Assessment of AV morphology, anatomy of the functional aortic annulus (FAA) and the aortic root with transesophageal echocardiography (TEE) improves the understanding of the mechanisms of AR. Pre- and intra-operative TEE plays a pivotal role in guiding case selection, surgical planning, and in evaluating procedural success. Post-operative transthoracic echocardiography is useful to determine long-term success and monitor for recurrence of AR.

Functional annulus remodelling using a prosthetic ring in tricuspid aortic valve repair: mid-term results

The functional aortic valve annulus (FAVA) is a complex unit with proximal (aorto-ventricular junction) and distal (sinotubular junction) components. The aim of our study was to evaluate the impact of the total FAVA remodelling, using a prosthetic ring, on mid-term clinical and echocardiographic results after aortic valve repair. Since February 2003, 250 patients with tricuspid aortic valve insufficiency (AI) underwent aortic valve repair. FAVA dilatation was treated by prosthetic ring in 52 patients, by isolated subcommissural plasty in 62, by subcommissural plasty plus ascending aortic replacement in 57 and by David's reimplantation procedure in 79. Survival rate and freedom from recurrent AI greater than or equal to moderate were evaluated by Kaplan-Meier. Overall late survival was 90.4%. Late cardiac-related deaths occurred in 15 patients. At follow-up, 36 (16%) patients had recurrent AI greater than or equal to moderate because of cusp reprolapse and/or FAVA redilatation. Freedom from recurrent AI was significantly higher for patients who underwent David's procedure or FAVA remodelling by prosthetic ring than those who underwent isolated subcommissural plasty (P < 0.01) or subcommissural plasty plus ascending aortic replacement (P = 0.02). There was no statistical difference between David's procedure and prosthetic ring annuloplasty (P = 0.26). FAVA remodelling using a prosthetic ring is a safe procedure in aortic valve repair surgery thanks to long-term annulus stabilization and it is a pliable alternative to David's procedure in selected patients. This technique may be used in all patients with slight root dilatation to avoid aggressive root reimplantation. We also recommended total FAVA annuloplasty in all patients who underwent aortic valve repair to improve long-term repair results.

Anatomy and pathophysiology of the ventriculo-aortic junction: implication in aortic valve repair surgery.

To understand the different mechanisms of aortic regurgitation (AR), the aortic valve needs to be considered as a functional unit composed of three structures: (I) the functional aortic annulus (FAA), comprising of the ventriculo-aortic junction (VAJ) and the sino-tubular junction (STJ) (Figure 1); (II) the leaflets with their attachment; and (III) the three sinuses of Valsalva. The different mechanisms of AR have been classified by our group in a repair-oriented classification, with particular importance given to the VAJ. Generally, along with the primary repair technique specific for each type of AR, a VAJ annuloplasty is required to restore the discrepancy between valve orifice and quantity of leaflet tissue (Figure 2) (1,2). Figure 1 Diagrammatical representation of the aortic root. a. sinotubular junction; b. Ventriculo-aortic junction, also called basal ring or surgical annulus; c. the sinuses of Valsalva Figure 2 Repair-oriented functional classification of aortic insufficiency (AI) with description of disease mechanisms and repair techniques used. FAA, functional aortic annulus; STJ, sinotubular junction; SCA, subcommissural annuloplasty In this review, we focus on the VAJ as a part of the FAA. We emphasize the role of the VAJ in the development of AR and the need for VAJ annuloplasty in AV repair. We describe the anatomy of the VAJ and the dynamics during the cardiac cycle. We also define its dimensions in normal and pathological aortic valve (AV). Finally, we analyze the different surgical solutions for VAJ annuloplasty.

Aortic Valve Insufficiency: Leaflet Reconstruction Techniques

The introduction of effective and durable leaflet repair techniques have enabled repair of the regurgitant aortic valve. Aortic valve repair is favored to avoid the placement of a prosthesis that the patient will likely outgrow. Furthermore, repair has the potential to reduce the incidence of prosthesis-related complications, including endocarditis, thromboembolism, anticoagulant-related hemorrhage, and reoperation. The primary goal of all aortic valve repair is to restore a durable surface of coaptation to the regurgitant valve. The key to successful leaflet repair for aortic insufficiency is a thorough understanding of the mechanism of dysfunction. We have developed a systematic approach to the assessment and repair of aortic insufficiency because of leaflet disease. The combination of leaflet repair and functional aortic annulus annuloplasty can restore the proper geometry of the aortic valve complex and allow for successful repair of aortic insufficiency caused by both restriction and prolapse.

Aortic valve repair: a glimpse into the future

Aortic valve repair: a glimpse into the future