Long-term results of the valve reimplantation technique using a graft with sinuses

Valve-Sparing Aortic Root Replacement State-of-the-Art Review, Part I: Anatomy and Physiology

Aortic valve disease is common, and valve-preserving operations are preferred whenever possible. Valve-sparing aortic root replacement has become an important tool for managing aortic root pathology in children and adults. The learning curve for this operation is challenging, but with increasing experience and technical modifications, early and late outcomes continue to improve. Durable long-term results vary based on the underlying anatomy, pathology, and patient selection, as well as surgeon expertise. The first installment of this Valve-Sparing Aortic Root Replacement State-of-the-Art Review article addresses patient anatomy and physiology as it relates to candidacy for VSRR.

Valve-sparing aortic root replacement-for all patients?

BACKGROUND

Valve-sparing root replacement (VSRR) has been associated with good survival and low rates of valve-related complications (VRCs). Whether these advantages are present irrespective of patient comorbidity or age is unclear. The aim of this study was to analyze survival and frequency of VRCs in relation to patient comorbidity and age.

METHODS

Between October 1995 and December 2021, 1156 patients with a bicuspid or tricuspid aortic valve were treated by root remodeling. The mean patient age was 53.3 ± 14 years, and 973 (84%) were male. The mean duration of follow-up was 6.7 ± 5.5 years (median, 5.9 years), and follow-up was 95% complete (7746 patient-years). We analyzed the population according to comorbidity and age at surgery. A discriminating cutoff for the effect of age was determined using receiver operating characteristic curve (ROC) analysis.

RESULTS

Mean survival at 15 years was 74.7 ± 2.5%. Deceased patients were older (mean, 65.3 ± 12 years vs 51.6 ± 14.1 years; P < .001) at the time of surgery and had more comorbidities (coronary artery disease [CAD], 28.4% vs 9.8%; P < .001). The sole significant adjusted predictor was age (P < .001). By ROC analysis (area under the curve, 0.780), the optimal cutoff for age was 61 years. Survival was 87.1 ± 2.8% at 15 years in patients age <61 years, compared to 55.3 ± 4.3% in patients age >61 years (P < .0001). Using competing risk analysis, VRC-free survival at 15 years was 66.8% at 15 years, including 76.7% in patients age <61 years and 52.4% in those age >61 years (P < .0001).

CONCLUSIONS

VSRR is associated with a low incidence of VRC and excellent durability. Survival is decreased in the presence of comorbidities, mainly CAD, and patient age >61 years. Despite lower survival, freedom from VRC is good.

Aortic root anatomy after aortic valve reimplantation

OBJECTIVE

During the last decade, special concerns have been raised about the anatomic relationships among the sinotubular junction, ventricular-aortic junction, and virtual basal ring to improve the results of root reconstruction. The aim of this study is to evaluate the in vivo anatomy of the aortic root after reimplantation with the Valsalva graft and the anatomic relationship between its components.

METHODS

We analyzed 10 consecutive patients with tricuspid aortic valves who underwent reimplantation with the Valsalva graft between September and December 2019. Surgical clips were applied as markers at the level of proximal annular knots and at the distal reimplanted commissures on the neo-sinotubular junction. Electrocardiogram-gated computed tomography scan of the aortic root was performed. Coordinates of the markers were exported on a 3-dimensional modeling software, and the distances between the virtual basal ring and the Dacron graft basal landmarks were measured.

RESULTS

The mean heights of Dacron graft basal landmarks from virtual basal ring were right-left commissure 7.1 ± 5.1 mm; right sinus 4.7 ± 4.1 mm; right-noncoronary commissure 2.8 ± 2.2 mm; noncoronary sinus 1.4 ± 1.6 mm; left-noncoronary commissure 2.2 ± 2.3 mm; and left sinus 2.0 ± 0.9 mm. The mean planar distances of basal Dacron graft landmarks from virtual basal ring (thickness) were right-left commissure 5.3 ± 3.1 mm; right sinus 2.8 ± 1.4 mm; right-noncoronary commissure 2.2 ± 1.5 mm; noncoronary sinus 1.5 ± 1.5 mm; left-noncoronary commissure 1.3 ± 1.0 mm; and left sinus 3.4 ± 2.5 mm.

CONCLUSIONS

After reimplantation, despite a complete dissection of the root, slight asymmetry of graft proximal seating exists. The inner annuloplasty is on the virtual basal ring, and the proximal edge of the Dacron graft is on the ventricular-aortic junction at a slightly different thickness and height along the annular circumference. At the level of the right sinus and left/right commissure, the Dacron graft is higher than the virtual basal ring and the relative wall thickness is increased. The annular stabilization is unaffected.

Current controversies in aortic valve-preserving surgery

The clinical outcome of severe aortic regurgitation (AR) remains suboptimal, but surgery has been shown to have survival benefit over medical therapy. Postoperative survival is inferior in patients with reduced left ventricular function, and therefore early surgical intervention is recommended. Aortic valvuloplasty (AVP) is an attractive option to avoid the major drawbacks of prosthetic valves but has not been widely adopted. The etiology of AR is classified functionally into three groups: normal leaflet motion (type I), cusp prolapse (type II), and restriction (type III). Type I with dilatation of the sinus of Valsalva (type Ib) can be repaired by aortic valve reimplantation or aortic root remodeling with similar valve stability. Type I with dilatation of the aortic annulus (type Ic) can be managed by annuloplasty. Type II can be corrected by plication or resuspension techniques. Pericardial patch is necessary in AVP for type Id (perforation/fenestration) and type III but is associated with risk of recurrence. Bicuspid aortic valve is classified according to commissure angle: symmetrical, asymmetrical, and very asymmetrical. Tricuspidization is recommended for repair of very asymmetrical valves to avoid postoperative stenosis. Recent progress has achieved similar reoperation rates between bicuspid and tricuspid aortic valve repair. For Marfan syndrome, valve-sparing root replacement is advantageous compared to Bentall operation regarding late survival, thromboembolic and hemorrhagic events, and endocarditis. Similar findings have been reported in acute aortic dissection. Both remodeling and reimplantation procedures provide similar favorable outcomes in these settings. Recent advances in AVP are summarized by quantitative assessment of cusp configuration (effective height and geometric height), graft size decision, use of template to cut the graft, and videoscopic assessment of post-repair cusp configuration. Due to these advances, AVP shows superior results to replacement surgery. Further concrete evidence with larger case volumes and longer observation periods are necessary to popularize AVP.

Outcomes and risk factors of late failure of valve-sparing aortic root replacement

OBJECTIVE

Retention of the native aortic valve when performing aortic root surgery for aneurysmal disease has become a more common priority. We reviewed our experience in valve-sparing aortic root replacement (VSARR) to evaluate the long-term outcomes and the risk factors for reoperation.

METHODS

From January 1994 through June 2017, 342 patients (mean age 47.8 ± 15.5 years, 253 [74%] male) underwent VSARR. The most common etiologies were connective tissue disease (n = 143, 42%) followed by degenerative aortic aneurysm (n = 131, 38%). Aortic regurgitation (moderate or greater) was present in 35% (n = 119).

RESULTS

Reimplantation technique was used in 90% patients (n = 308). Valsalva graft was used in 38% patients (n = 131) and additional cusp repair was done in 15% (n = 50). Operative mortality was 1% (n = 5). The median follow-up time was 8.79 years (interquartile range, 4.08-13.51). The cumulative incidence of reoperation (while accounting for the competing risk of death) was 8.4%, 12.8%, and 17.1% at 5, 10, and 15 years, respectively. There were no differences in survival and incidence of reoperation between root reimplantation and remodeling. Larger preoperative annulus diameter was associated with greater risk of reoperation (hazard ratio, 1.10; 95% confidence interval, 1.02-1.19, P = .01). The estimated probability of developing severe aortic regurgitation after VSARR was 8% at 10 years postoperatively. Operative mortality, residual aortic regurgitation at dismissal, and survival improved in recent times with more experience.

CONCLUSIONS

VSARR is a viable and safe option with good long-term outcomes and low rates of late aortic valve replacement. Dilated annulus preoperatively was associated with early repair failure.

Reimplantation versus aortic ring annuloplasty in bicuspid valve with borderline aortic root ectasia

Objective

Methods

Results

Conclusions

Long-Term Outcomes after Aortic Valve and Root Replacement in a Very High-Risk Population

Background: Aortic valve and root replacement (AVRR) is a standardised procedure to treat patients with aortic valve and root disease. In centres with a well-established aortic valve and root repair program (valve repairs and Ross operations), only patients with very complex conditions receive AVRR; this procedure uses a mechanical or biological composite valve graft (modified Bentall-de Bono procedure). The aim of the study was to evaluate the short- and long-term results after AVRR in a high-risk population with complex pathologies. Methods: Between 2005 and 2018, a total of 273 consecutive patients (mean age 64 ± 12.8 years; 23% female) received AVRR. The indication for surgery was an acute type A aortic dissection in 18%, infective endocarditis in 36% and other pathologies in 46% patients; 39% were redo procedures. The median EuroSCORE II was 11.65% (range 1.48-95.63%). Concomitant surgery was required in 157 patients (58%). Results: The follow-up extended to 5.2 years (range 0.1-15 years) and it was complete in 96% of the patients. The 30-day mortality was 17%. The overall estimated survival at 5 and 10 years was 65% ± 3% and 49% ± 4%, respectively. Univariate and multivariate logistic regression analyses revealed the following risk factors for survival: perioperative neurological dysfunction (OR 5.45), peripheral artery disease (OR 4.4) and re-exploration for bleeding (OR 3.37). Conclusions: AVRR can be performed with acceptable short- and long-term results in a sick patient population. The Bentall-De Bono procedure may be determined to be suitable for only elderly or high-risk patients. Any other patients should receive an AV repair or the Ross procedure in well-established centres.

Valve-sparing versus valve-replacing aortic root replacement in patients with aortic root aneurysm

BACKGROUND

Valve-sparing aortic root replacement (VSARR) is an alternative to valve-replacing aortic root replacement (VRARR) with valved-conduits based on recent guidelines for clinical practice. This study investigated outcomes of these two procedures in patients with nonstenotic valves.

METHODS

Between January 7, 2007 and June 30, 2019, 475 patients with aortic root aneurysm without aortic stenosis underwent VSARR (151) or VRARR (324) techniques. Propensity score-matching (PSM) was used to alleviate confounding. Endpoints were 30-day mortality, 8-year survival and reoperation, aortic regurgitation, and valve gradients.

RESULTS

PSM created 69 pairs of patients with a mean age 52 ± 13 years (10.1% Marfan syndrome, 34.8% bicuspid aortic valve). There was no statistically significant difference in major perioperative morbidity or 30-day mortality (0% VSARR vs. 1.4% VRARR; p = 0.316). Overall survival was significantly higher (p = 0.025) in the VSARR group versus the VRARR group (8-year estimates 100% vs. 88.9%, respectively), while freedom from valve reoperation was similar (p = 0.97, 8-year estimates 90.9% vs. 96.7%, respectively). Freedom from > moderate-severe AR was not significantly different (p = 0.08, 8-year estimates 90.0% VSARR group vs. 100% VRARR), but mean valve gradients at last follow-up were better in the VSARR group (5.9 vs. 13.2 mmHg, p < 0.001).

CONCLUSIONS

VSARR is a safe operation in patients with aortic root aneurysm and nonstenotic aortic valves in the hands of experienced surgeons. Freedom from reoperation is similar and the mode of aortic valve failure differs between the two groups.

Long-term outcomes after aortic root repair using selective sinus replacement

OBJECTIVES

The study aim was to evaluate long-term results after anatomic restoration of the aortic root.

METHODS

During an 18-year period, a total of 669 patients underwent valve-sparing root repair (aneurysm 554, dissection 115) using selective sinus replacement. None/trivial, mild, moderate, and severe (grades 3+ and 4+) insufficiency were present in 57, 146, 204, and 262 patients, respectively.

RESULTS

The anatomic repair was adjusted to the existing aortic annulus diameter, which was 27.0 ± 3.0 mm on average. Replacement of 1, 2, or 3 sinuses of Valsalva was performed in 209, 234, and 226 patients, respectively. Altogether, 454 additional procedures on the cusps were performed, mostly as cusp patch plasty with pericardium (210). Thirty-day mortality was 0.6%. The mean follow-up duration was 7.1 ± 4.1 years (range, 0.01-19.1 years). The estimated freedom from relevant aortic insufficiency grade 3+ or greater (15 events) was 98% ± 1%, 97% ± 1%, and 94% ± 3% at 5, 10, and 15 years, respectively. On echocardiogram, no patient revealed a considerable change of the form or size of the repaired root, which was confirmed radiologically in 160 patients who received computed tomography angiography for any reason. Multivariate logistic regression analysis identified cusp prolapse/pseudo-prolapse as the only independent risk factor for the development of recurrent insufficiency grade 2+ or greater (41 occurrences), with a hazard ratio of 3.258 (95% confidence interval, 1.658-6.403; P = .001). An association between aortic annulus size and functional results could not be demonstrated.

CONCLUSIONS

Patient-tailored root repair using isolated sinus replacement offers excellent functional long-term results regardless of underlying root pathology or annulus size. Aortic cusp pathology was decisive for long-term valve function.

Case Report: Severe Aortic Valve Regurgitation and Pseudoaneurysm in Aortic Valve-Sparing Operation: The Usefulness of Multimodality Imaging in a Complex Clinical Scenario

Background: Failure of the native aortic valve and degenerative anatomy of ascending aorta in patients with previous Tirone-David operation may represent a clinical challenge, because sometimes the risk of reoperation is prohibitive. Case: We described the case of a patient suffering from severe aortic valve regurgitation and pseudoaneurysm of the aortic arch, 6 years after cardiac surgery operation. The aim of this clinical case was to assess if the complex anatomy of aortic pseudoaneurysm and aortic root geometry can be accurately reproduced from contrast-enhanced computed tomography scan into a three-dimensional (3D) printed model. Based on this procedural method, with the aid of transesophageal 3D ultrasound, we efficaciously treated the patient percutaneously with a combination of transcatheter occluder device plus microcoil embolization and transfemoral aortic valve implantation. The patient was free from complications and the need to redo cardiac surgery. Conclusion: To the best of our knowledge, this is the first description of two simultaneous complications and their staged treatment in a patient with previous aortic valve-sparing operation. This is a useful report in a single 3D model applying such specific technology to these two simultaneous clinical settings.

The Ross procedure and valve-sparing root replacement procedures in the adult patient: do guidelines follow the evidence?

Prosthetic aortic valve replacements have long been the mainstay of valvular surgery due to their favorable outcomes and low operative complexity. Yet, mechanical valves require lifelong anticoagulation, whereas bioprosthetic valves increase the risk for earlier and more frequent reoperation. Alternative reconstructive techniques have been proposed to address these challenges. These include valve-sparing root replacement procedures if the native aortic valve can be salvaged, and the Ross procedure, which nearly eliminates prosthetic valve-related thromboembolism, anticoagulation-related hemorrhage and endocarditis. Both procedures are technically more complex and thus subject to surgeons' volume and expertise compared to conventional aortic valve replacements. However, they are associated with more favorable outcomes compared to aortic valve replacements if performed by experienced surgeons, especially in younger patients. Nevertheless, despite the growing high-quality literature supporting both procedures, existing multi-society guidelines fail to acknowledge the strength of evidence in support of valve-sparing root replacement procedures and the Ross procedure. In this review, we summarize the existing long-term evidence for the use of each procedure, describe the current guidelines for the treatment of aortic valve pathology, and propose the reevaluation of guidelines based on the available clinical evidence.

Two decades of valve-sparing root reimplantation in tricuspid aortic valve: impact of aortic regurgitation and cusp repair

OBJECTIVES

Our goal was to analyse the influence of preoperative aortic regurgitation (AR) on the necessity of cusp repair during valve-sparing reimplantation (VSR). We focused on patients with tricuspid aortic valves (TAV) and evaluated the impact of AR and cusp repair on long-term outcomes.

METHODS

From March 1998 to December 2018, a total of 512 consecutive patients underwent VSR at our institution; of these, 303 had a TAV. The mean age was 53 ± 15 years, and the median follow-up was 6.12 years. The rate and type of cusp repair were analysed based on preoperative AR. Time-to-event analysis was performed, as well as risk of death, reoperation and AR recurrence.

RESULTS

Cusp repair was necessary in 168 (55.4%) patients; the rate rose significantly as AR grade increased (P < 0.001). In-hospital mortality was 1% (n = 3). At 5 and 10 years, overall survival was 92 ± 2% and 75 ± 5%, respectively. Freedom from valve reoperation was 95 ± 2% and 90 ± 3%. Freedom from AR >2+ and AR >1+ at 10 years was 88 ± 4% and 70.4 ± 4.6%, respectively. Independent predictors of death included age, New York Heart Association functional class and type-A aortic dissection. Predictors of AR greater than mild included previous cardiac surgery and severe preoperative AR.

CONCLUSION

In patients with TAV receiving VSR, the necessity of cusp repair increased with the degree of preoperative AR. Preoperative AR and cusp repair do not impact long-term survival and aortic valve reoperation, but severe preoperative AR and multiple cusp repair increase the risk of recurrent moderate-to-severe AR. Overall, cusp repair seems to attenuate the negative impact of preoperative AR for at least 1 decade in a majority of patients.

Root Reimplantation and Aortic Annuloplasty With External Ring in Bicuspid Aortic Valve: An Anatomical Comparison

Aortic annuloplasty has demonstrated to be a protective factor in valve-sparing root replacement and aortic valve repair. Both reimplantation for aortic root aneurysms and external ring annuloplasty for isolated aortic regurgitation have demonstrated good long-term results. The aim of this anatomical study is to compare aortic reimplantation with Valsalva graft with aortic external ring annuloplasty in bicuspid aortic valves, analyzing their morphological features with CT scan. We selected 56 patients with bicuspid aortic valve who underwent reimplantation procedure with Valsalva graft or external ring annuloplasty; after propensity-matching, 2 homogeneous groups of 10 patients each were obtained. Through multiplanar ECG-gated CT-Scan reconstructions, pre- and postoperative, aortic annular, and valve geometrical characteristics were compared (diameters, perimeter, area and ellipticity index for the annulus; effective height, coaptation length and commissural height for the valve). Aortic root volume was also analyzed. Postoperative comparison of the two groups showed similar geometric features of the aortic annulus in terms of major and minor diameters, perimeter, area and ellipticity index. Analysis of valve's parameters showed similar results in terms of effective height and coaptation length (respectively 10.9 ± 2.1 mm and 7.5 ± 1.9 mm in External Ring group and 10.1 ± 2.0 mm and 7.6 ± 1.6 mm in the Reimplantation group). Both techniques achieve an efficient annuloplasty with similar anatomical results on bicuspid the aortic valves. The stability of these results needs to be confirmed by long-term clinical and echocardiographic follow-up.

Influence of aneurysmal aortic root geometry on mechanical stress to the aortic valve leaflet

AIMS

While mechanical stress caused by blood flow, e.g. wall shear stress (WSS), and related parameters, e.g. oscillatory shear index (OSI), are increasingly being recognized as key moderators of various cardiovascular diseases, studies on valves have been limited because of a lack of appropriate imaging modalities. We investigated the influence of aortic root geometry on WSS and OSI on the aortic valve (AV) leaflet.

METHODS AND RESULTS

We applied our novel approach of intraoperative epi-aortic echocardiogram to measure the haemodynamic parameters of WSS and OSI on the AV leaflet. Thirty-six patients were included, which included those who underwent valve-sparing aortic root replacement (VSARR) with no significant aortic regurgitation (n = 17) and coronary artery bypass graft (CABG) with normal AV (n = 19). At baseline, those who underwent VSARR had a higher systolic WSS (0.52 ± 0.12 vs. 0.32 ± 0.08 Pa, respectively, P < 0.001) and a higher OSI (0.37 ± 0.06 vs. 0.29 ± 0.04, respectively, P < 0.001) on the aortic side of the AV leaflet than those who underwent CABG. Multivariate regression analysis revealed that the size of the sinus of Valsalva had a significant association with WSS and OSI. Following VSARR, WSS and OSI values decreased significantly compared with the baseline values (WSS: 0.29 ± 0.12 Pa, P < 0.001; OSI: 0.26 ± 0.09, P < 0.001), and became comparable to the values in those who underwent CABG (WSS, P = 0.42; OSI, P = 0.15).

CONCLUSIONS

Mechanical stress on the AV gets altered in correlation with the size of the aortic root. An aneurysmal aortic root may expose the leaflet to abnormal fluid dynamics. The VSARR procedure appeared to reduce these abnormalities.

Current trends in aortic valve-preserving surgery

The natural history of aortic regurgitation is not as benign as once believed, even in asymptomatic patients with preserved left ventricular function. Aortic valve surgery can prolong survival in these patients. However, both mechanical and biological aortic valve replacement have major disadvantages, especially in young patients. Aortic valve-preserving surgery has attracted a great deal of attention because it has a significant survival benefit over replacement. Nonetheless, aortic valve-preserving surgery has not been widely adopted due to the complexity of the technique and assessment (i.e., long learning curve). With recent technical and theoretical advances, aortic valve-preserving surgery has increasingly been performed with better outcomes, and therefore earlier surgical intervention in cases of aortic regurgitation has been considered. Recent advances in aortic valve-preserving surgery include repair-oriented classification of the etiology of aortic regurgitation, objective assessment of the cusp configuration (i.e., effective height and geometric height), use of aortic annuloplasty, introduction of two reproducible valve-sparing root replacement procedures (i.e., aortic valve reimplantation and aortic root remodeling techniques), standardization of aortic valve-preserving surgery, and assessment of cusp configuration with aortoscopy. A number of prospective multicenter studies are currently underway and will clarify the role of aortic valve-preserving surgery in the treatment of aortic regurgitation in the near future.

Long-term experience with valve-sparing root reimplantation surgery in tricuspid aortic valve

Objective

To analyze our long-term experience with valve-sparing reimplantation technique in treating aortic root aneurysm, aortic regurgitation, and aortic dissection in patients with tricuspid aortic valve.

Methods

Between March 1998 and October 2018, 303 consecutive patients underwent valve-sparing reimplantation in our institution. The mean age of this cohort was 52.9 ± 15 years. Time to event analysis was performed with the Kaplan-Meier method. Risk of death, reoperation, and aortic regurgitation (AR) recurrence were analyzed using the cox-regression method.

Results

In-hospital mortality was 1% (n = 3) of which two were admitted for acute aortic dissection. Median follow-up was 5.81 years ([IQR]: 2.8-10 years). Thirty-nine patients (14.4%) died during follow-up. At 5 and 10 years, overall survival was 92 ± 2%and 75 ± 4.9%, respectively. Seventeen patients required late aortic valve reoperation. Freedom from valve reoperation was 95 ± 2% and 90 ± 3%. Freedom from AR > 2+ and AR > 1+ at 10 years was 91 ± 4% and 71.5 ± 4.6%, respectively. Significant multivariate predictors of death included age, New York Heart Association dyspnea class (NYHA), type A acute dissection (TAAD), and preoperative left ventricular end-diastolic diameter (LVEDD). Significant multivariate predictors of AR recurrence included indication for surgery, previous cardiac surgery, and presence of preoperative AR. Freedom from events like major bleeding, thromboembolic events, and infective endocarditis at 10 years were 97%, 98%, and 96%, respectively.

Conclusions

Aortic valve-sparing with the reimplantation technique has been performed for over two decades in our institution, and the results in patients with tricuspid aortic valve (TAV) are excellent in terms of survival and freedom from valve-related adverse outcomes including valve reoperation. These results continue supporting the use of valve sparing root replacement using the reimplantation technique (VSRR) in patients with aortic aneurysm, irrespective of whether they have preoperative AR or not. VSRR is safe, durable, and reproducible, but further follow-up, well into the second decade is still necessary.

Comprehensive Ex Vivo Comparison of 5 Clinically Used Conduit Configurations for Valve-Sparing Aortic Root Replacement Using a 3-Dimensional-Printed Heart Simulator

Supplemental Digital Content is available in the text.

Background:

Many graft configurations are clinically used for valve-sparing aortic root replacement, some specifically focused on recapitulating neosinus geometry. However, the specific impact of such neosinuses on valvular and root biomechanics and the potential influence on long-term durability are unknown.

Methods:

Using a custom 3-dimenstional–printed heart simulator with porcine aortic roots (n=5), the anticommissural plication, Stanford modification, straight graft (SG), Uni-Graft, and Valsalva graft configurations were tested in series using an incomplete counterbalanced measures design, with the native root as a control, to mitigate ordering effects. Hemodynamic and videometric data were analyzed using linear models with conduit as the fixed effect of interest and valve as a fixed nuisance effect with post hoc pairwise testing using Tukey’s correction.

Results:

Hemodynamics were clinically similar between grafts and control aortic roots. Regurgitant fraction varied between grafts, with SG and Uni-Graft groups having the lowest regurgitant fractions and anticommissural plication having the highest. Root distensibility was significantly lower in SG versus both control roots and all other grafts aside from the Stanford modification (P≤0.01 for each). All grafts except SG had significantly higher cusp opening velocities versus native roots (P<0.01 for each). Relative cusp opening forces were similar between SG, Uni-Graft, and control groups, whereas anticommissural plication, Stanford modification, and Valsalva grafts had significantly higher opening forces versus controls (P<0.01). Cusp closing velocities were similar between native roots and the SG group, and were significantly lower than observed in the other conduits (P≤0.01 for each). Only SG and Uni-Graft groups experienced relative cusp closing forces approaching that of the native root, whereas relative forces were >5-fold higher in the anticommissural plication, Stanford modification, and Valsalva graft groups.

Conclusions:

In this ex vivo modeling system, clinically used valve-sparing aortic root replacement conduit configurations have comparable hemodynamics but differ in biomechanical performance, with the straight graft most closely recapitulating native aortic root biomechanics.

4D flow CMR analysis comparing patients with anatomically shaped aortic sinus prostheses, tube prostheses and healthy subjects introducing the wall shear stress gradient: a case control study

BACKGROUND

Anatomically pre-shaped sinus prostheses (SP) were developed to mimic the aortic sinus with the goal to preserve near physiological hemodynamic conditions after valve-sparing aortic root replacement. Although SP have shown more physiological flow patterns, a comparison to straight tube prosthesis and the analysis of derived quantitative parameters is lacking. Hence, this study sought to analyze differences in aortic wall shear stress (WSS) between anatomically pre-shaped SP, conventional straight tube prostheses (TP), and age-matched healthy subjects) using time-resolved 3-dimensional flow cardiovascular magnetic resonance (4D Flow CMR). Moreover, the WSS gradient was introduced and analyzed regarding its sensitivity to detect changes in hemodynamics and its dependency on the expression of secondary flow patterns.

METHODS

Twelve patients with SP (12 male, 62 ± 9yr), eight patients with TP (6 male, 59 ± 9yr), and twelve healthy subjects (2 male, 55 ± 6yr) were examined at 3 T with a 4D Flow CMR sequence in this case control study. Six analysis planes were placed in the thoracic aorta at reproducible landmarks. The following WSS parameters were recorded: WSSavg (spatially averaged over the contour at peak systole), max. WSSseg (maximum segmental WSS), min. WSSseg (minimum segmental WSS) and the WSS Gradient, calculated as max. WSSseg - min. WSSseg. Kruskal-Wallis- and Mann-Whitney-U-Test were used for statistical comparison of groups. Occurrence and expression of secondary flow patterns were evaluated and correlated to WSS values using Spearman's correlation coefficient.

RESULTS

In the planes bordering the prosthesis all WSS values were significantly lower in the SP compared to the TP, approaching the physiological optimum of the healthy subjects. The WSS gradient showed significantly different values in the four proximally localized contours when comparing both prostheses with healthy subjects. Strong correlations between an elevated WSS gradient and secondary flow patterns were found in the ascending aorta and the aortic arch.

CONCLUSION

Overall, the SP has a positive impact on WSS, most pronounced at the site and adjacent to the prosthesis. The WSS gradient differed most obviously and the correlation of the WSS gradient with the occurrence of secondary flow patterns provides further evidence for linking disturbed flow, which was markedly increased in patients compared to healthy sub jects, to degenerative remodeling of the vascular wall.

In vitro evaluation of a new aortic valved conduit

BACKGROUND

This study examined whether the presence of a sinus of Valsalva equivalent in the KONECT RESILIA aortic valved conduit (Edwards Lifesciences, Irvine, Calif) improves valve hemodynamics, kinematics, and performance.

METHODS

A 28-mm KONECT RESILIA aortic valved conduit was used to create an in vitro flow test model, and the same aortic valved conduit model without a sinus section was used as a control. Particle image velocimetry and hydrodynamic characterization experiments were conducted in the vicinity of the valves in a validated left-heart simulator at 3 cardiac output levels. In addition, leaflet kinematics of the valves were determined through en face high-speed imaging.

RESULTS

The KONECT RESILIA aortic valved conduit model exhibited lower mean and peak transvalvular pressure gradients than the control model at all 3 cardiac outputs. In addition, its leaflets opened more fully than did those of the valved conduit without the sinuses, yielding greater effective and geometric orifice areas. It was found that the presence of the sinuses not only facilitated the development of larger and more stable vortices at the initial stages of the cardiac cycle but also helped to maintain these vortices during the late stages of the cardiac cycle, leading to smoother valve closure.

CONCLUSIONS

The KONECT RESILIA aortic valved conduit reproduces the bulged section of the aortic root corresponding to the sinuses of Valsalva. With this Valsalva-type conduit, larger orifice areas were observed, improving valve hemodynamics that may enhance performance.

Morphology of Sinus of Valsalva After Aortic Valve-Sparing Root Replacement Using Valsalva Graft

Utilization of the Gelweave Valsalva graft (Terumo Vascutek, Tokyo, Japan) for David-type valve-sparing aortic root replacement was still controversial because this prosthesis did not completely reproduce the native sinus of Valsalva. We focused on the morphology of pseudo-Valsalva sinus after the reimplantation procedure and evaluated our novel crimp plication stitch from the viewpoint of morphology of Valsalva sinus at midterm follow-up periods.

Novel insights by 4D Flow imaging on aortic flow physiology after valve-sparing root replacement with or without neosinuses

OBJECTIVES

This study was undertaken to evaluate the flow dynamics in the aortic root after valve-sparing root replacement with and without neosinuses of Valsalva reconstruction, by exploiting the capability of 4D Flow imaging to measure in vivo blood velocity fields and 3D geometric flow patterns.

METHODS

Ten patients who underwent valve-sparing root replacement utilizing grafts with neosinuses or straight tube grafts (5 cases each) were evaluated by 4D Flow imaging at a mean of 46.5 months after surgery. We used in-house processing tools to quantify relevant bulk flow variables (flow rate, stroke volume, peak velocity and mean velocity), wall shear stresses and the amount of flow rotation characterizing the region enclosed by the graft and the aortic valve leaflets.

RESULTS

Despite bulk flows with similar peak velocities, flow rates and stroke volumes (P = 0.31-1.00), the neosinuses graft was associated with a lower mean velocity (P < 0.03) and magnitude of wall shear stress along the axial direction of the vessel wall (P < 0.05) at the proximal root level but remained comparable along the circumferential direction (P = 0.22-1.0) to the straight tube graft. Flow rotation was evidently and systematically higher in the neosinuses grafts, characterized by streamline rotations higher than 270°, nearly triple that of tubular grafts (10.3 ÷ 14.0% of all aortic streamline vs 2.2 ÷ 5.7%, P = 0.008).

CONCLUSIONS

Recreation of the sinuses of Valsalva during valve-sparing root replacement is associated with significantly lower wall shear stress and organized vortical flows at the level of the sinus that are not evident using the straight tube graft. These findings need confirmation in larger studies and could have important implications in terms of aortic valve durability.

Early and long-term results of aortic valve sparing aortic root reimplantation surgery for bicuspid and tricuspid aortic valves

Introduction:

To evaluate early and long-term clinical outcomes following aortic valve sparing aortic root reimplantation surgery in patients with leaking bicuspid and tricuspid aortic valves.

Methods:

The study consisted of 92 consecutive adult patients (tricuspid aortic valve group = 63 and bicuspid aortic valve group = 29) who underwent aortic valve sparing aortic root reimplantation surgery with or without aortic cusp repair for dilatation of the aortic root and/or aortic valve regurgitation at our institution from April 2004 to October 2016. Clinical outcomes were investigated using Kaplan–Meier and log-rank tests between groups.

Results:

The follow-up was 100% complete with a mean time of 5.3 ± 3.3 years. The 30-day in-hospital mortality was 3.1% in tricuspid aortic valve group and 3.4% in bicuspid aortic valve group patients. The overall survival rates at 10 years did not differ between bicuspid aortic valve and tricuspid aortic valve patient groups (96.6 ± 3.3% vs. 90.3 ± 4.2%, p = 0.3). Freedom from recurrent aortic valve regurgitation (>2+) at 10 years was 90.5 ± 4.1% in tricuspid aortic valve group and 75.7 ± 8.7% in bicuspid aortic valve group (p = 0.06). Freedom from aortic valve reoperation at 10 years was 100% in tricuspid aortic valve group and 83.9 ± 7.4% in bicuspid aortic valve group (p = 0.002).

Conclusion:

Aortic valve sparing aortic root reimplantation surgery is a safe and efficient technique, providing acceptable long-term survival with low rates of valve-related complications in both tricuspid aortic valve and bicuspid aortic valve patient groups. However, aortic valve reoperation rates at 10 years follow-up were higher in bicuspid aortic valve group patients compared to tricuspid aortic valve group patients.

Modified sizing technique with newly designed tools to facilitate the valve sparing aortic root replacement "David" procedure with mid-term results

BACKGROUND

Valve sparing root replacement differs in specific points. The main target remains to achieve a perfect intraoperative result and long-term stability. We aimed in this study to present our modified sizing technique for valve-sparing "David" procedure and its mid-term results.

METHODS

We present a retrospective single-center study. A newly designed sizing ring in addition to triple-armed forceps (Trifeet®) was used to measure the proper size of the Valsalva® prosthesis for patients undergoing David-procedure. Primary endpoints are intraoperative aortic regurgitation (AR) and early postoperative outcomes. Secondary endpoints included freedom from aortic regurgitation or reoperation and overall mortality.

RESULTS

A total of 63 consecutive patients who underwent David procedure between 09/2012 and 12/2016 were evaluated. Mean age was 52±15 years and 76.2% were male. Moderate to severe aortic regurgitation was reported in 60 (95.2%) patients. Four (6.3%) patients presented with type-A aortic dissection, 20 (31.7%) patients had bicuspid and 3 (4.8%) had a unicuspid aortic valve, 2 (3.2%) patients had a prior aortic valve repair. Intraoperative echocardiography revealed no 34 (54%), trace 26 (41.2%) or moderate 3 (4.8%) AR. Stroke, myocardial infarction, and 30-day mortality occurred in 1 patient (1.6%). During follow-up 5 (7.9%) patients needed reoperation due to recurrent AR within a mean of 35±18 months. One could be re-repaired, and the other four underwent aortic valve replacement. A second patient died in the late follow-up.

CONCLUSIONS

Our modified sizing technique simplifies the "David-procedure" and allows to achieve a good intraoperative and mid-term results. However, these results have to be confirmed in a larger cohort with a long-term follow-up.

4D flow characterization of aortic blood flow after valve sparing root reimplantation procedure

Valve-sparing aortic root replacement (VSRR) with reimplantation technique is an effective alternative for young patients with dilated roots and preserved cusps, which avoids the risks of lifelong anticoagulation or valve degeneration. New grafts with anatomically-shaped sinuses have been developed in order to preserve aortic root physiology, which could decrease complication rates and improve durability. However, controversy remains regarding the effect of recreation of the sinuses of Valsalva during VSRR on long-term outcomes. The novel 4D flow technique, exploiting its unique ability to combine anatomical evaluation of the root with fluid-dynamic assessment of aortic flow, enables integrated analysis of the close interaction between graft design, valvular morphology and three-dimensional (3D) flow characteristics. Early experimental studies have shown how graft shape affects the aortic root flow pattern, formation of vortexes and helicity of downstream flow; however, the clinical significance of these findings is yet to be clarified. Various and still unexplored knowledge can be obtained from the qualitative and quantitative analysis of these complex datasets, that could shed more light on which is the best among myriad surgical techniques and grafts adopted in VSRR. The extraordinary potential 4D flow imaging opens new boundless horizons in the perspective of an increasingly patient-tailored surgical planning.

Which technique of cusp repair is durable in reimplantation procedure?

OBJECTIVES

We aimed to ascertain the durability of cusp repair techniques used in reimplantation procedures.

METHODS

Between 2000 and 2015, 249 patients (mean age, 49 ± 17 years) with aortic insufficiency underwent the reimplantation procedure. The pathology was acute aortic dissection in 24 and non-dissection in 225 patients. Preoperative aortic regurgitation (AR) was absent in 9, 1+ in 19, 2+ in 20, 3+ in 71 and 4+ in 120 patients. The mean aortic root and ascending aortic diameters were 47 ± 9 mm and 38 ± 7 mm, respectively. The following techniques of cusp repair were used: none (83), central plication (130), free margin reinforcement (57) and patch repair (19). Annual echocardiography was performed. Freedom from moderate aortic insufficiency and aortic valve reoperation were calculated by the Kaplan-Meier method. Factors influencing the freedom from moderate or severe AR were calculated by proportional hazard analysis.

RESULTS

Mean follow-up period was 56  ±  44 months. Freedom from moderate or severe AR was 82%±3% and 77% ± 4% at 5 and 8 years, respectively, whereas freedom from aortic valve reoperation was 93%±8% and 87% ± 3% at 5 and 8 years, respectively. Recurrent AR and infection were causes of reoperation in 13 and 3 patients, respectively. Preoperative cusp prolapse, technique of free margin reinforcement used and patch repair were significant factors for recurrent AR by proportional hazard analysis. Central plication was not a significant factor for recurrent AR.

CONCLUSIONS

Preoperative cusp prolapse was a risk factor, whereas central plication was not a risk factor for recurrent AR. Free margin reinforcement had a positive effect, whereas patch repair had a negative effect on aortic valve durability.

Biological solutions to aortic root replacement: valve-sparing versus bioprosthetic conduit

Composite valve graft implantation described by Bentall and De Bono is a well-documented technique of aortic root replacement used for a large spectrum of pathologic conditions involving the aortic valve and the ascending aorta. While mechanical valves were initially used, biological prostheses were later introduced in order to avoid long-term anticoagulation and its related complications. The increasing age of patients who undergo aortic root surgery, and data supporting the use of a biological aortic valve in the younger population, have significantly increased the need for a composite biological valved conduit. However, parallel to the increased use of biological valve in the context of a Bentall operation, aortic valve-sparing (AVS) operation have also been performed in a growing number of patients. Sarsam and David described the remodeling and the reimplantation procedures more than 25 years ago with the aim of sparing otherwise normal aortic valves in the presence of a root aneurysm. Important achievements in this discipline have occurred over the past decade including development and refinement of valve preserving aortic root replacement techniques, development of a classification system for aortic insufficiency, surgical approaches to cusp disease with different cusp anatomy. Both procedures can now provide excellent root reconstruction and adequate clinical results in terms of late valve durability. The AVS technique offers several advantages over the Bentall procedure, such as no need for oral anticoagulation and lifestyle adjustments. AVS operations have become established alternatives to Bentall procedures for patients with aortic root pathology. However, data comparing the safety and durability of these approaches are lacking.

Perspective: valve sparing root repair: tips and tricks

The remodeling and the reimplantation procedures were described more than 25 years ago with the aim of sparing otherwise normal aortic valves in the presence of a root aneurysm. Important achievements in this discipline have occurred over the past decade including development and refinement of valve preserving aortic root replacement techniques, development of a classification system for aortic insufficiency, and development of surgical approaches to cusp disease with varying cusp anatomy. The main advantage of the reimplantation is the resulting annular support, and the disadvantages are the unfavorable hemodynamics and relatively longer procedural time. Conversely, the main advantages of remodeling are the physiological hemodynamics and the shorter procedural time, and the disadvantage is the lack of annular support. With technical advances and modifications, however, the differences between these two procedures have narrowed. Today preference for a reimplantation procedure is based on the perception of a better reproducibility of the surgical procedure, an increased procedural safety due to the characteristic hemostatic feature of this surgical approach, the possibility of achieving favorable hemodynamics, and a much larger amount of data present in the literature on long-term results.

Standardized Technique of Aortic Valve Re-implantation for Valve-sparing Aortic Root Replacement

Despite the obvious advantages of the preservation of a normal aortic valve during aortic root replacement, the complexity of valve sparing procedures prevents a number of cardiac surgeons from incorporating them into their practice. The aim of this protocol is to describe a simplified and user-friendly technique of an aortic valve-sparing root replacement (VSRR) procedure by re-implantation of the aortic valve. Proper selection of patients and limitations of the technique are discussed. In 54 consecutive patients, normal appearing aortic valves were re-implanted in a commercially available polyester prosthesis with pre-shaped sinuses by a simplified and standardized technique. Placement of the first row of the proximal suture line, choice of the prosthesis size, and adjustment of the height of the commissures of the patient to the fixed height of the sinus portion of the prosthesis were slightly modified from the reference techniques with the aim of increasing its feasibility for use by other cardiac surgeons. Early mortality and morbidity as well as 5-year survival, freedom from aortic valve reoperation, and freedom from recurrent moderate regurgitation were collected in all patients. Thirty-day mortality, re-sternotomy for bleeding, re-sternotomy for mediastinitis, and the incidence of stroke were very low, 1.8% for each (1 of 54). No patient required permanent pace-maker implantation. At 5 years, survival, freedom from aortic valve reoperation, and freedom from recurrent moderate regurgitation were 97.5%, 95.2%, and 91.6%, respectively. Mid-term results of our standardized technique of re-implantation of the aortic valve for valve-sparing aortic root replacement are very good and compare with more complex techniques reported by experienced surgeons. By following the present protocol of the standardized re-implantation technique, a greater number of cardiac surgeons can perform this procedure with comparable good results.

Biological solutions to aortic root replacement: valve-sparing versus bioprosthetic conduit‡

OBJECTIVES

Valve-sparing operations and root replacement with a biologic composite conduit are viable options in aortic root aneurysm. This study was conceived to compare the early and mid-term results of these 2 procedures.

METHODS

From September 2002 to November 2015, 749 consecutive patients underwent either a valve-sparing operation or a root replacement with a biologic composite conduit at 2 institutions. Propensity score matching was used to compare similar cohorts of patients in the overall population and in the ≤ 55 and ≥ 65-year age groups.

RESULTS

Overall operative mortality was 0.4%, mean age 57.4 ± 14.3 years, 84.6% were male. Individuals in the biologic composite conduit group were older and had worse preoperative risk profiles [chronic pulmonary disease (5.5% vs 0.9%; P  = 0.001), diabetes (6.4% vs 1.5%; P  = 0.001) and NYHA > 2 (25.2% vs 5.2%; P  < 0.001)]. Mean follow-up was 27.5 ± 28.4 months. In the unmatched population, there was no difference in in-hospital deaths (0 in the valve-sparing versus 3 in the biologic composite conduit group; P  = 0.12). These findings were confirmed in the propensity-matched populations. During follow-up, more patients in the biologic composite conduit group underwent reoperation on the aortic valve (2.6% vs 1.5%; P  = 0.026) resulting in a freedom from reoperation of 97.4% vs 98.5%, respectively. Separate analysis for patients stratified by age revealed no difference in outcomes.

CONCLUSIONS

In case of aortic root aneurysm, both valve-sparing operations and root replacement with a biologic composite conduit provide excellent outcomes. However, at mid-term follow-up the use of biologic composite conduit is associated with a higher risk of reoperation.

The influence of Marfans and bicuspid valves on outcomes following aortic valve reimplantation

BACKGROUND

We analyzed our early and midterm results with aortic valve reimplantation surgery to determine the influence of Marfan syndrome and bicuspid valves on outcomes with this technique.

METHODS

Between March 2004 and December 2015, 267 patients underwent aortic valve reimplantation operations. The mean diameter of the sinuses of Valsalva was 50 ± 3 mm and moderate/severe aortic regurgitation was present in 34.4% of these patients. A bicuspid aortic valve was present in 21% and 40% had Marfan syndrome.

RESULTS

Overall 30-day mortality was 0.37% (1/267). Mean follow-up was 59.7 ± 38.7 months. Overall survival at 1, 3, and 5 years was 98 ± 8%, 98 ± 1%, and 94 ± 2%, respectively. Freedom from reoperation and aortic regurgitation >II was 99 ± 5%, 98 ± 8%, 96.7 ± 8%, and 99 ± 6%, 98 ± 1%, 98 ± 1%, respectively at 1, 3, and 5 years follow-up, with no differences between Marfan and bicuspid aortic valve groups. (p = 0.94 and p = 0.96, respectively). No endocarditis or thromboembolic complications were documented, and 93.6% of the patients did not receive any anticoagulation therapy.

CONCLUSIONS

The reimplantation technique for aortic root aneurysms is associated with excellent clinical and functional outcomes at short and mid-term follow-up.