Ventriculo-aortic Junction Research Articles

Abstract 13643: Impact of Aortic Valve Repair and Valve-sparing Procedures on the Mitral Annular Geometry Assessed by 3-dimensional Transesophageal Echocardiography

Background: Annular non-planarity, the "saddle-shape" of the mitral valve (MV) annulus, plays a role in minimizing leaflet stress and preserving valve function. Aortic valve (AV) repair/sparing procedures are increasingly used to treat aortic regurgitation (AR). The impact of these procedures on MV geometry and function is unknown. Methods: 2D and 3D transesophageal echocardiography (TEE) of the MV was acquired pre-operatively and immediately after surgery in 30 patients with severe AR and/or aortic root dilatation (Group 1 (n=10): bicuspid AV undergoing AV repair and valve-sparing root replacement with AV reimplantation; Group 2 (n=10): tricuspid AV undergoing AV repair and AV reimplantation; Group 3 (n=10): isolated AV cusp repair) and in 10 controls (Group 4). MV morphology was assessed by dedicated quantification software (fig. 1). Results: Comorbidities were similar in all groups. Groups 1, 2 and 3 had increased LV end-diastolic volumes compared to group 4 (214±90, 193±56, 180±55 vs. 86± 28ml for groups 1, 2, 3 and 4, respectively; p<0.001); LVEF was similar (59.5 ± 6.2%). The baseline dimensions of the ventriculo-aortic junction and sinuses of Valsalva were larger in groups 1 and 2 vs. groups 3 and 4 (p<0.0001). AV and MV parameters are summarized (table). Pre-operative MV parameters did not differ from those of normal subjects. The annular height and annular height to commissural width ratio (AHCWR) significantly decreased after surgery in groups 1 and 2, as did the tenting area. Significant changes in the coaptation depth and mitro-aortic angle were only found in group 1. Conclusions: AV repair/sparing procedures alter the MV geometry, including the non-planarity of the annulus and the depth of coaptation of the leaflets, especially among patients with a bicuspid AV undergoing AV reimplantation. These alterations could have long-term implications on MV function.

IMPACT OF AORTIC VALVE REPAIR AND VALVE-SPARING PROCEDURES ON THE MITRAL ANNULAR GEOMETRY ASSESSED BY 3-DIMENSIONAL TRANSESOPHAGEAL ECHOCARDIOGRAPHY

Background: Annular non-planarity, the saddle-shape of the mitral valve (MV) annulus, plays a role in minimizing leaflet stress and preserving valve function. Aortic valve (AV) repair/sparing procedures are increasingly used to treat aortic regurgitation (AR). The impact of these procedures on MV geometry and function is unknown. Methods: 2D and 3D transesophageal echocardiography (TEE) of the MV was acquired pre-operatively and immediately after surgery in 30 patients with severe AR and/or aortic root dilatation (Group 1 (n=10): bicuspid AV undergoing AV repair and valve-sparing root replacement with AV reimplantation; Group 2 (n=10): tricuspid AV undergoing AV repair and AV reimplantation; Group 3 (n=10): isolated AV cusp repair) and in 10 controls (Group 4). MV morphology was assessed by dedicated quantification software (fig. 1). Results: Comorbidities were similar in all groups. Groups 1, 2 and 3 had increased LV end-diastolic volumes compared to group 4 (214±90, 193±56, 180±55 vs. 86± 28ml for groups 1, 2, 3 and 4, respectively; p<0.001); LVEF was similar (59.5 ± 6.2%). The baseline dimensions of the ventriculo-aortic junction and sinuses of Valsalva were larger in groups 1 and 2 vs. groups 3 and 4 (p<0.0001). AV and MV parameters are summarized (table). Pre-operative MV parameters did not differ from those of normal subjects. The annular height and annular height to commissural width ratio (AHCWR) significantly decreased after surgery in groups 1 and 2, as did the tenting area. Significant changes in the coaptation depth and mitro-aortic angle were only found in group 1. Conclusions: AV repair/sparing procedures alter the MV geometry, including the non-planarity of the annulus and the depth of coaptation of the leaflets, especially among patients with a bicuspid AV undergoing AV reimplantation. These alterations could have long-term implications on MV function.

Relationship of Normal Aortic Valve Cusp Dimensions: A Tool to Optimize Cusp Reconstruction Valvuloplasty

Outcomes of surgical aortic valvuloplasty hinge primarily on optimal leaflet design. Imprecise valve reconstruction can result in insufficiency or stenosis. Predicting postrepair leaflet parameters from pre- or intraoperative readily measurable valve dimensions could result in improved reconstruction. This study analyzes the relationships between different parameters of the normal aortic valve to establish a method of deriving the optimal dimensions of the reconstructed leaflet following valvuloplasty. Morphologic analysis of the normal aortic valve was performed on 50 autopsy specimens. The following parameters were measured: circumference at ventriculoaortic junction, intercommissural circumferential distance (IC), commissural height, leaflet free-margin length (L1-length of the free margin of each leaflet), cusp attachment length (L2-cusp attachment length at the ventriculoaortic junction), and leaflet height (A-ie, the vertical or cephalocaudal distance along the convex surface of the leaflet from the midpoint of the leaflet free margin to the midpoint of the cusp attachment). Univariate linear regression analysis was used to test the interdependence of leaflet dimensions. The leaflet free-margin length L1 correlated strongly with the corresponding IC: r = 0.74, 0.81, and 0.79 for noncoronary, right coronary, and left coronary leaflets, respectively; P = 0.000. Leaflet height A and cusp attachment length L2 also correlated well with the corresponding IC: A-IC, r = 0.56, 0.74, and 0.66; and L2-IC, r = 0.78, 0.85, and 0.80 for noncoronary, right coronary, and left coronary cusps respectively; P = 0.000. Parameters required to construct an aortic valve leaflet can be reliably derived from the IC, which can be easily measured perioperatively. Using this as a basis for leaflet reconstruction might optimize the leaflet graft design process, compensate for pathologic variations in aortic annulus size and commissural height, and could result in better coaptation of the valve leaflets.

Impact of aortic annular geometry on aortic valve insufficiency: Insights from a preclinical, ex vivo, porcine model

ObjectivesWe sought to create a model of aortic insufficiency in a left heart simulator combined with 3-dimensional echocardiography and finite element modeling of the aortic valve. We examined the effects of aortic root geometry alteration on aortic insufficiency. MethodsPorcine aortic roots were analyzed on a left heart simulator before (control, n = 8) and after intervention (n = 8). Intervention entailed 3 vertical incisions at the sinotubular junction with diamond-shaped patches incorporated into the defects to increase the sinotubular junction diameter. Hemodynamic parameters were assessed, including regurgitant volume and fraction. Video and echocardiography images evaluated aortic valve function, coaptation surface area, aortic insufficiency, and effective regurgitant orifice area. Finite element modeling corroborated relationships between root geometry and aortic insufficiency, and examined cusp stress. ResultsThe intervention resulted in a sinotubular junction diameter increase of 55% ± 4%. The sinotubular junction to ventriculo-aortic junction diameter ratio was significantly higher in the intervention group (1.89 ± 0.16 vs 1.47 ± 0.04, P = .02). Increased sinotubular junction diameter resulted in aortic insufficiency assessed by regurgitant volume (28 ± 7 mL vs 5 ± 2 mL, P = .004), regurgitant fraction (36% ± 5% vs 7% ± 1%, P < .001), and effective regurgitant orifice (15 ± 5 mm2 vs 0 mm2, P = .016). Intervention coaptation surface area was smaller (1.03 ± 0.11 cm2 vs 1.80 ± 0.08 cm2, P < .001). There was a linear correlation between increased sinotubular junction/ventriculo-aortic junction ratio and regurgitant fraction (R2 = 0.65, P = .003). The finite element modeling demonstrated a similar relationship between increasing sinotubular junction diameter and aortic insufficiency severity, and between end-diastolic cusp stresses and sinotubular junction diameters (R2 = 0.98, P < .001). ConclusionsIn this model, increasing sinotubular junction diameter is linearly related to reduced coaptation surface area and increasing aortic insufficiency severity. This model provides new insights into aortic insufficiency mechanisms and may be used to evaluate novel interventions for aortic valve repair.

Structure and function of the tricuspid and bicuspid regurgitant aortic valve: an echocardiographic study.

The emerging new treatment options for aortic valve disease call for more sophisticated diagnostics. We aimed to describe the echocardiographic pathophysiology and characteristics of the purely regurgitant aortic valve in detail. Twenty-nine men, with chronic aortic regurgitation without concomitant heart disease referred for aortic valve intervention, underwent 2D transoesophageal echocardiographic (TEE) examination prior to surgery according to a previously published matrix. Measurements of the aortic valve apparatus in long and short axis view were made in systole and diastole and analysed off-line. The aortic valves were grouped as tricuspid (TAV) or bicuspid (BAV), and classified by regurgitation mechanism. Twenty-four examinations were eligible for analysis of which 13 presented TAV and 11 BAV. The regurgitation mechanism was classified as dilatation of the aorta in 6 cases, as prolapse in 11 cases and as poor cusp tissue quality or quantity in 7 cases. The ventriculo-aortic junction (VAJ) and valve opening were closely related (TAV r = 0.5, BAV r = 0.73) but no correlation was found between the VAJ and the maximal sinus diameter (maxSiD) or the sinotubular junction (STJ). However, the STJ and maxSiD were significantly related (TAV vs BAV: systole r = 0.9, r = 0.8; diastole r = 0.9, r = 0.7), forming an entity. The conjoined BAV cusps were shorter than the anterior cusps when closed (P = 0.002); the inter-commissural distances of the cusps in the BAV group were significantly different (P = 0.001 resp. 0.03) in both systole and diastole. The VAJ was independent of other aortic dimensions and should thereby be considered as a separate entity with influence on valve opening. The detailed 2D TEE measurements of this study add further important information to our knowledge about the function and echocardiographic anatomy of the pathological aortic valve and root either as a stand-alone examination or as a benchmark and complement to 3D echocardiography. This may have an impact on decisions regarding repairability of the native aortic valve.

Aortic valve repair update.

The key for successful valve repair is full understanding of the regurgitant mechanism and sufficient evaluation of the valve. Currently, multidetector computed tomography has been introduced for evaluation. The aortic valve can be analyzed in details preoperatively. The main causes of aortic regurgitation (AR) in the adult population are degenerative leaflet change and annulus dilatation. Restoration to normal structure can be accomplished mainly by plication. Central leaflet plication near the Arantius nodule is a simple technique for redundant tissue. For leaflet deficiency, pericardial patch plasty may be an option. No universal technique exists for plication of the aortic annulus. The valve-sparing aortic root replacement firmly stabilizes the ventriculo-aortic junction (VAJ) and assures repair durability even in patients with mild to moderate root dilatation. Subcommissural annuloplasty (Cabrol stitch) does not seem sufficient for the prevention of VAJ dilatation. Circumferential annuloplasties may have a greater potential. However, convenient device for annular plication is still in development. The bicuspid aortic valve is a congenital heart valve lesion. A basic technique is free margin plication of the fused leaflet. Aortic root dilatation may contribute to AR severity. Valve-sparing aortic root replacement may improve repair durability. Considering the great advances in valve repair, young patients with AR should be informed that valve repair is a promising option for surgical treatment.

Aortic root geometry in bicuspid aortic insufficiency versus stenosis: implications for valve repair.

The contribution of aortic annular and root disease in bicuspid aortic valve (BAV) insufficiency remains unclear. We compared aortic root geometry between BAV stenosis and aortic insufficiency (AI), before and after repair. Patients presenting for surgery for BAV insufficiency (n = 58) were compared with patients with BAV stenosis (n = 58). Clinical and transoesophageal echocardiographic data were collected, including end-diastolic diameters of the ventriculo-aortic junction (VAJ), aortic root, sinotubular junction (STJ) and ascending aorta (AA). AI patients were younger and more likely to be male compared with aortic stenosis (AS) patients. VAJ, aortic root and STJ diameters were significantly larger in AI compared with AS patients (30 ± 0.5 vs 25 ± 0.4 mm, P < 0.001; 41 ± 0.8 vs 34 ± 0.6 mm, P < 0.001; 36 ± 0.9 vs 30 ± 0.6 mm, P < 0.001, respectively). Following multivariable adjustment for age, sex, body surface area and ascending aortic diameter, these diameters remained larger in AI patients with a mean difference of 3, 6 and 4 mm, respectively (all P < 0.001). Mean AA diameter in the AI group was similar to the AS group (37 ± 1.0 vs 34 ± 0.8 mm, P = 0.06). Forty (69%) AI patients had BAV repair with a mean reduction in VAJ and STJ diameters of 5 and 9 mm compared with prerepair (P < 0.0001). Despite the absence of aortic aneurysms, aortic annulus and root dimensions are significantly larger in patients with BAV insufficiency compared with stenosis. Alterations in aortic root geometry contribute to the pathophysiology of BAV insufficiency and require correction for a successful repair.

Surgical anatomy of the aortic root: Implication for valve-sparing reimplantation and aortic valve annuloplasty

BackgroundTo enhance the reproducibility of aortic valve–sparing reimplantation and annuloplasty, we analyzed the topographic relationship between the ventriculoaortic junction (VAJ), basal ring (BR), and sinotubular junction (STJ). The root base thickness is also quantified. MethodFifty-eight fresh human aortic valves were analyzed. The root was dissected to the limit where the aortic wall terminates into the cardiac structures (VAJ). Root height was measured externally from the STJ to the VAJ and internally from the STJ to the BR defined as the plane passing through the cusps nadir. The root base thickness was measured at the BR and orthogonal to the internal wall; except at the right coronary sinus, where it was measured between the BR internally and the VAJ externally. Measurements were taken at the middle of the 3 sinuses and commissures. ResultsThe VAJ is at the same level as the BR from the noncoronary sinus (−0.1 ± 0.9 mm) to the left coronary sinus (0.5 ± 1.3 mm); it is above the BR from the left/right commissure (4.6 ± 1.4 mm) to the right/non commissure (2.5 ± 1.6 mm). The external root height was highest at the non/left commissure (21.5 ± 2.6 mm) followed by the right/non commissure (19.2 ± 2.3 mm) then the left/right commissure (15.7 ± 2.2 mm) (P < .05). The mean root base thickness was 3.2 mm, ranging from 1 ± 0 mm at the left/non commissure to 6.2 ± 1.2 mm at the right coronary sinus (P < .001). ConclusionsThe VAJ is not planar; it is above the level of the BR from the left/right to the right/non commissure. As a consequence, the external height of the non/left commissure is greater than the other 2 commissures. These findings should be taken into consideration when performing aortic valve–sparing reimplantation or external annuloplasty.

Effect of annulus dimension and annuloplasty on bicuspid aortic valve repair†

We have recently shown that valve sparing reimplantation (VSR) improves the durability of bicuspid aortic valve repair in comparison with subcommissural annuloplasty. The aim of this study was to assess the degree of annular reduction provided by these techniques and to correlate these findings with repair durability. From 1995 to 2010, 161 patients underwent bicuspid valve repair. We included only patients with subcommissural annuloplasty or reimplantation having intraoperative pre- and post-repair transoesophageal echocardiography images. Pre- and post-repair ventriculo-aortic junction (VAJ) diameters were measured on long axis views. Inclusion criteria were met by 53 patients with subcommissual annuloplasty and 65 with reimplantation. Median follow-up was 53 months in the subcommissual annuloplasty group and 42 months in the reimplantation group. Follow-up completeness was 100% in subcommissural annuloplasty and 94% in reimplantation. There was no operative or late mortality. Mean preoperative VAJ was similar in both groups (reimplantation: 28 ± 3 mm vs subcommissural annuloplasty: 28 ± 3, P = 0.16). Preoperative VAJ was larger in patients <40 years and with aortic regurgitation (AR) ≥ 3+ (P < 0.01). Mean postoperative VAJ was smaller in reimplantation compared with subcommissural annuloplasty (21 ± 2 mm vs 24 ± 3 mm, P < 0.01). In univariate analyses, subcommissural annuloplasty, preoperative VAJ ≥ 30 mm, postoperative VAJ ≥ 25 mm and cusp repair with patch were predictive of recurrent AR > 1+. In the subcommissural annuloplasty group, VAJ≥ 30 mm preoperatively and ≥ 25 mm postoperatively were associated with decreased 6 years freedom from recurrent AR>1+ (<30 mm: 74% vs ≥ 30 mm: 39%, P = 0.01; <25 mm: 80% vs ≥ 25 mm 31%, P = 0.02) In the reimplantation group, VAJ dimension had no effect on recurrent AR >1+ (P = 0.93). In bicuspid aortic valve repair, the circumferential annuloplasty of VSR offers greater reduction of VAJ compared with the non-circumferential annuloplasty provided by the subcommissural annuloplasty. The degree and extent of VAJ reduction in reimplantation seem to be factors among others that positively influence repair durability particularly in patients with a large VAJ (≥ 30 mm).

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.

Transesophageal Echocardiographic Imaging of Aortic Valve Replacement Using Autologous Glutaraldehyde-Treated Pericardium

Transesophageal Echocardiographic Imaging of Aortic Valve Replacement Using Autologous Glutaraldehyde-Treated Pericardium

Aortic annuloplasty: a new aspect of aortic valve repair

study because this is the technique that has been the most used in clinical practice for ventriculo-aortic junction reduction and stabilization. Of course, it has an effect on valve coaptation. It increased the coaptation by plications, or if you prefer, by closing the subcommissural triangle. This portion of the aortic root is just above what we considered to be the ventriculo-aortic junction, so I think it must be considered as a VAJ annuloplasty. Regarding your second question, we have seen that after noncircumferential annuloplasty, as with subcommissural annuloplasty, you may have recurrent dilatation because the portions between the plication are not supported. We have also observed that the pledget used in subcommissural annuloplasty stitches can migrate inside the aortic wall. Those are the mechanisms explaining the loss of efficacy over time of the subcommissural annuloplasty. With a prosthetic ring annuloplasty, as in the reimplantation technique, for example, you stabilize the annulus circumferentially with a prosthesis, as you also do in mitral or tricuspid annuloplasty. You really have another reinforcement of the annulus than happens with subcommissural annuloplasty. Long-term follow-up data on mitral and tricuspid valve repair or on the Tirone David operation suggest that the annuloplasty rings are probably more stable than the de Vega annuloplasty or the subcommissural annuloplasty.

In vitro comparison of three techniques for ventriculo-aortic junction annuloplasty

In aortic valve repair, reduction and stabilization of the ventriculo-aortic junction (VAJ) is generally recommended. In this in vitro study, we compare three techniques of annuloplasty: the subcommissural annuloplasty (SCA), the internal ring (IR) and the external ring (ER) annuloplasty. Ten fresh porcine aortic valve preparations were tested in a pulsatile mock loop. Each sample was tested untreated (baseline: B). The annuloplasty techniques were then performed successively in each sample. Each technique was tested, then removed and the following technique performed. SCA was applied at 50% of interleaflet triangle height; the ER and IR were applied with a moderate reduction (15-20%) of the VAJ. Hydrodynamic, video and echographic parameters were collected. Flow rate and arterial pressure were maintained consistently between groups. Effective orifice area decreased significantly with each annuloplasty technique compared with baseline (P<0.001). Mean transvalvular pressure drop was significantly higher in the ER and IR vs SCA (P=0.007). Annuloplasty reduced valve opening and closing time in comparison to baseline. Echocardiography confirmed that the VAJ experienced a greater reduction with the ER and IR vs SCA. A narrowing of the lower third of the sinuses of Valsalva was observed after the ER, and subvalvular narrowing was observed after the IR. Valve coaptation increased with all annuloplasty techniques. The three annuloplasty techniques examined demonstrated differential effects on aortic valve function and root morphology. The ER and IR have greater potential to reduce VAJ diameter in comparison to SCA. The IR induced a subvalvular remodelling of the VAJ, whereas the ER induced a paravalvular remodelling.

Aortic valve repair: a glimpse into the future

Aortic valve repair: a glimpse into the future

Valve sparing-root replacement with the reimplantation technique to increase the durability of bicuspid aortic valve repair

To assess root replacement and annular stabilization in bicuspid aortic valve repair, we compared results of reimplantation technique versus subcommissural annuloplasty or no annuloplasty. Between 1995 and 2010, 161 consecutive patients underwent bicuspid aortic valve repair. Patients undergoing subcommissural annuloplasty or no annuloplasty (group 1, n=87) had larger root dimensions and less aortic insufficiency than did patients undergoing reimplantation technique (group 2, n=74). We matched groups 1 to 1 on basis of those criteria. After matching (n=106, n=53 per group), root dimensions (41.5 ± 5 vs 40 ± 4 mm; P=.2) and degree of insufficiency (2.6 ± 1.2 vs 2.7 ± 1; P=.6) were similar between groups. Techniques of cusp repair were similar between groups. Group 2 had smaller preoperative left ventricular size (P=.02), fewer concomitant procedures (P=.02), and shorter follow-up (41 ± 30 vs 63 ± 40 months; P=.003). There were no in-hospital deaths. At discharge, residual aortic insufficiency was similar between groups, but peak gradient greater than 25 mm Hg was more frequent in group 1 (13% vs 30%; P=.04). At 6 years, overall survival was 98% ± 3% in both groups. Freedoms from reoperation and aortic insufficiency greater than 2+ were significantly better in group 2 (100% vs 90% ± 8%; P=.03; 100% vs 77% ± 14%; P=.002). In bicuspid aortic valve repair, root replacement with the reimplantation technique stabilizes the ventriculoaortic junction, improves valve mobility (low gradient), and is associated with improved outcomes.

Evaluation of Multislice Computed Tomography Early After Transcatheter Aortic Valve Implantation With the Edwards SAPIEN Bioprosthesis

Currently, imaging assessment of patients who undergo transcatheter aortic valve implantation is based mainly on echocardiography and angiography, both limited to provide a 3-dimensional evaluation of the prosthesis within the native valve. This study involved 34 patients who underwent multislice computed tomography (MSCT) after transcatheter aortic valve implantation. Prosthesis expansion and circularity, depth of implantation, apposition degree at the ventriculoaortic junction, and positioning in relation to coronary artery ostia were evaluated. Early clinical events such as aortic regurgitation and periprocedural conduction abnormalities were recorded and correlated with multislice computed tomographic findings. MSCT provided comprehensive 3-dimensional assessments of the prostheses in 31 of 34 of patients (91%). Expansion was excellent (mean expansion ratio 100.0 ± 10.4%) and increased significantly from the ventricular side to the aortic side of the prosthesis. Circular deployment was achieved in most patients and increased from the ventricular to the aortic side. Mean implantation depth was -2.4 ± 2.5 mm, associated with a low rate (12%) of permanent pacemaker implantation. Patients with a new conduction abnormalities had the deepest prosthesis implantation, associated with lesser expansion and circularity. Perfect apposition on MSCT was associated with a low rate of significant aortic regurgitation. In conclusion, MSCT is able to provide an accurate 3-dimensional evaluation of prosthesis deployment and positioning after transcatheter aortic valve implantation. Moreover, these anatomic findings correlate with the most frequent early complications (i.e., the occurrence of aortic regurgitation and conduction abnormalities).

Circumferential Disruption of the Ventriculo-Aortic Junction Due to Infective Endocarditis: Surgical Repair with Custom-made, Accurately Sized, Pericardial Tube

Repair of circumferential ventriculo-aortic annular disruption following infective endocarditis is technically challenging. We present an approach for systematic repair and describe a technique for preparation of an accurately sized pericardial tube graft.

In-vitro comparison of the original and modified dePaulis prosthesis for valve-sparing aortic root replacement

Objectives: Valve sparing root replacement techniques are attractive, the type of the procedure is still under discussion regarding root stabilisation and leaflet stress. The native root is composed of three straight commissural pillars between the ventriculo-aortic and sinotubular junction. This shape is not entirely imitated by the dePaulis root prosthesis. Therefore a more physiological designed root prosthesis was developed.

Ventriculo-aortic junction in human root. A geometric approach

With advances in tissue engineering and improvement of surgical techniques, stentless biological valves and valve-sparing procedures have become alternatives to traditional aortic valve replacement with stented bioprostheses or mechanical valves. New surgical techniques preserve the advantages of native valves but require better understanding of the anatomical structure of the aortic root. Silicone rubber was injected in fresh aortic roots of nine human cadavers under the physiological closing pressure of 80 mmHg. The casts reproduced every detail of the aortic root anatomy and were used to digitize 27 leaflet attachment lines (LALs) of the aortic valves. LALs were normalized and described with a mathematical model. LALs were found to follow a pattern with the right coronary being the largest followed by the non-coronary and then the left coronary. During diastole, the aortic valve LAL can be described by an intersection between a created tube and an extruded parabolic surface. This geometrical definition of the LAL during end diastole gives a better understanding of the aortic root anatomy and could be useful for heart valve design and improvement of aortic valve reconstruction technique.

New graft formulation and modification of the David reimplantation technique

Two controversies of the reimplantation technique 1 for valve-sparing aortic root replacement are how to choose the graft size and the role of neosinuses. Dating back to the original David-Feindel formula that was based on an assumption that “the internal radius of the ventriculo-aortic junction (the annulus) . . . is two thirds of the leaflet height,” surgeons have had difficulty determining optimal graft size. David, in fact, has changed his graft formulation strategy at least 3 times. Part of the impetus for the modifications in technique was the recognition that recreating aortic sinus segments is important to minimizing stress on the aortic cusps during systole. Data suggest that the techniques currently used still cause undue stress (albeit improved) on the cusps, even with recreation of neosinuses. The principal hypothesis of this report is that the formulations in use probably underestimate optimal sinus diameter. An alternative and simpler formula with modification of the reimplantation technique is presented.