Restitution of the Aortic Valve: What is New, What is Proven, and What is Obsolete?

Valve-Sparing Aortic Root Replacement State-of-the-Art Review, Part II: Surgical Techniques

Aortic valve disease is common, and valve-preserving operations are preferred whenever possible. Valve-sparing aortic root replacement (VSRR) 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 underlying anatomy, pathology, and patient selection, as well as surgeon expertise. Part II of this VSRR State-of-the-Art Review article provides technical pearls related to VSRR.

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.

Automatic measurement of the sinus of Valsalva by image analysis

BACKGROUND AND OBJECTIVES

Despite the importance of the morphology of the sinus of Valsalva in the behavior of heart valves and the proper irrigation of coronary arteries, the study of these sinuses from medical imaging is still limited to manual radii measurements. This paper aims to present an automatic method to measure the sinuses of Valsalva on medical images, more specifically on cine MRI and Xray CT.

METHODS

This paper introduces an enhanced method to automatically localize and extract each sinus of Valsalva edge and its relevant points. Compared to classical active contours, this new image approach enhances the edge extraction of the Sinus of Valsalva. Our process not only allows image segmentation but also a complex study of the considered region including morphological classification, metrological characterization, valve tracking and 2D modeling.

RESULTS

The method was successfully used on single or multiplane cine MRI and aortic CT angiographies. The localization is robust and the proposed edge extractor is more efficient than the state-of-the-art methods (average success rate for MRI examinations=84% ± 24%, average success rate for CT examinations=89% ± 11%). Moreover, deduced measurements are close to manual ones.

CONCLUSIONS

The software produces accurate measurements of the sinuses of Valsalva. The robustness and the reproducibility of results will help for a better understanding of sinus of Valsalva pathologies and constitutes a first step to the design of complex prostheses adapted to each patient.

Does aortic valve repair in valve-sparing aortic root reconstruction compromise the longevity of the procedure?

OBJECTIVES:

The effect of performing aortic valve repair in combination with valve-sparing operation on the length of time for which patients are free from reoperation is unclear. The objective of this study was to determine if the performance of aortic valve repair during valve-sparing operation modified the freedom from reoperation time.

METHODS:

From January 2003 to July 2014, 78 patients with a mean age of 49±15 years underwent valve-sparing operation. Sixty-eight percent of these patients were male. Twenty-two (28%) aortic valve repair procedures were performed in this patient population. In the aortic valve repair + valve-sparing operation group, 77.3% of patients had moderate/severe aortic insufficiency, while in the valve-sparing operation group, 58.6% of patients had moderate/severe aortic insufficiency (ns = not significant). Additionally, 13.6% of patients in the aortic valve repair + valve-sparing operation group had functional class III/IV, while 14.2% of patients in the valve-sparing operation group had functional class III/IV (ns).

RESULTS:

The in-hospital and late mortality rates, for the aortic valve repair + valve-sparing operation and valve-sparing operation groups were similar, as they were 4.5% and 3.6%; and 0% and 1.8%, respectively. In the aortic valve repair + valve-sparing operation group, 0% of patients presented moderate/severe aortic insufficiency during late follow-up, while in the valve-sparing operation group, 14.2% of patients presented with moderate/severe aortic insufficiency during this period (ns). In the aortic valve repair + valve-sparing operation group, 5.3% of patients presented with functional class III/IV, while in the valve-sparing operation group, 4.2% of patients presented with functional class III/IV (ns). In the aortic valve repair + valve-sparing operation group, 0% of patients required reoperation, while in the valve-sparing operation group, 3.6% of patients required reoperation over a mean follow-up period of 1621±1156 days (75 patients).

CONCLUSION:

Valve-sparing operation is a safe and long-lasting procedure and performance of aortic valve repair when necessary does not increase risk of reoperation on the 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.

Valve-sparing aortic root replacement

The aortic root has a unique 3-dimensional configuration and the distinctive function of supporting the aortic valve and blood vessels. The sinuses of Valsalva are crucial to create appropriate eddy currents that are important in initiating and coordinating aortic valve closure and promoting coronary artery blood flow. Most aneurysms in the aortic root are associated with degenerative changes in the elastic media rather than atherosclerosis. Valve-sparing root repair has become widely accepted, although the Bentall procedure remains the gold standard. Because reimplantation using the Valsalva graft allows root geometry to be retained and theoretically and practically prevents recurrent aortic valve regurgitation, it is considered the most reliable and preferred technique among various valve-sparing aortic root repair procedures.

Aortic regurgitation after valve-sparing aortic root replacement: modes of failure

BACKGROUND

Despite the positive clinical results of valve-sparing aortic root replacement, little is known about the causes of reoperations and the modes of failure.

METHODS

From October 1999 to June 2010, 101 patients underwent valve-sparing aortic root replacement using the David reimplantation technique. The definition of aortic root repair failure included the following: (1) intraoperative conversion to the Bentall procedure; (2) reoperation performed because of aortic regurgitation; and (3) aortic regurgitation equal to or greater than a moderate degree at the follow-up. Sixteen patients were considered to have repair failure. Three patients required intraoperative conversion to valve replacement, 3 required reoperation within 3 months, and another 8 required reoperation during postoperative follow-up. At initial surgery 5 patients had moderate to severe aortic regurgitation, 6 patients had acute aortic dissections, 3 had Marfan syndrome, 2 had status post Ross operations, 3 had bicuspid aortic valves, and 1 had aortitis. Five patients had undergone cusp repair, including Arantius plication in 3 and plication at the commissure in 2.

RESULTS

The causes of early failure in 6 patients included cusp perforation (3), cusp prolapse (3), and severe hemolysis (1). The causes of late failure in 10 patients included cusp prolapse (4), commissure dehiscence (3), torn cusp (2), and cusp retraction (1). Patients had valve replacements at a mean of 23 ± 20.9 months after reimplantation and survived.

CONCLUSIONS

Causes of early failure after valve-sparing root replacement included technical failure, cusp lesions, and steep learning curve. Late failure was caused by aortic root wall degeneration due to gelatin-resorcin-formalin glue, cusp degeneration, or progression of cusp prolapse.

Automatic evaluation of the Valsalva sinuses from cine-MRI

OBJECT

Although, there is no global consensus on their measurement, magnetic resonance imaging (MRI) appears to be particularly attractive for the study of the sinuses of Valsalva (SV). The purpose of this study was to automatically evaluate the SV from cine-MRI using a standardized method.

MATERIALS AND METHODS

An automatic method based on mathematical morphology was elaborated to segment the aortic root from cross-sectional cine-MRI, and to detect relevant points, such as the commissures, the cusps and the centre of the SV. The distances between these points allow a metric evaluation of the SV. Our method was tested on synthesized data and 41 patient data sets and radii calculations were compared with manual processing.

RESULTS

On the patient data sets, there are excellent correlation and concordance between manual and automatic measurements for images at diastole (r=0.97; y=0.97x+0.57; P<10(-5); mean of differences=0.2 mm; standard deviation of differences=2.0 mm) and at systole (r=0.96; y=0.96x+1.2; P<10(-5); mean of differences<0.1 mm; standard deviation of differences=2.4 mm).

CONCLUSION

Our automatic method provides reliable morphometric evaluation of the SV. Measures of distances between relevant points allow a precise evaluation of each cusp of the SV. This robust evaluation can be helpful in the follow-up of patients with aortic root diseases.

Quality of life after aortic root surgery: reimplantation technique versus composite replacement

BACKGROUND

Recent studies indicate the safety of the aortic valve reimplantation technique (David operation) in the long-term follow-up. The aim of this study was to compare the results of the David operation with those of the aortic composite replacement procedure, with the focus on quality of life (QoL).

METHODS

Within a 6-year period, 143 patients received either an aortic composite replacement (composite group, n = 67) or the David-I operation (David group, n = 76). The QoL of 108 patients (87% of the living patients) was evaluated postoperatively by the 36-Item Short Form Health Survey. A subgroup analysis of QoL excluded patients with aortic stenosis and type A acute aortic dissection.

RESULTS

Hospital survival rates (89.6% versus 97.4%, p = 0.102), as well as actuarial 1-year survival rate (86.6% versus 91.9%) and 3-year survival rate (81.1% versus 91.9%) proved more successful among the David group. Incidences of serious adverse events during the follow-up period (10.8% versus 28.3%, p = 0.008) were higher for patients of the composite group. The QoL was found to be compromised for patients of the composite group, in relation to all criteria outlined in the 36-Item Short Form Health Survey. Subgroup analysis without patients with dissection and aortic stenosis demonstrated a significantly better postoperative QoL for patients of the David group. Patients belonging to the composite group were more frequently compromised by prosthetic valve noise (p < 0.001).

CONCLUSIONS

This study demonstrates the superiority of the aortic valve reimplantation compared with the aortic composite replacement, regarding both clinical outcome and postoperative QoL.

Valve-Sparing Reconstruction Within the Native Aortic Root: Integrating the Yacoub and the David Methods

I propose an integrated valve-sparing aortic root reconstruction that combines the surgical principles of both the Yacoub and David methods. Valve re-suspension is first completed within the native aortic root; then the graft is anchored to the pledget-reinforced, scalloped true aortic annulus.

Aortic Valve Preservation in Patients With Aortic Root Aneurysm: Results of the Reimplantation Technique

BACKGROUND

A study was conducted to determine the long-term results of aortic valve reimplantation to treat aortic root aneurysm.

METHODS

Prospective follow-up with clinical assessments and echocardiography was done of 167 consecutive patients who had reimplantation of the aortic valve as treatment of aortic root aneurysm. Their mean age was 45 +/- 15 years, 78% were men, 38% had Marfan syndrome, 14% had aortic dissection, and 7% had bicuspid aortic valve. The aortic valve was reimplanted into a straight Dacron (Dupont, Wilmington, DE) tube in 89 patients and in a Dacron tube with creation of neoaortic sinuses in 78. Aortic cusp repair was performed in 66 patients, and the free margin was reinforced with a fine Gore-Tex suture (W.L. Gore & Assoc, Flagstaff, AZ) in 36. The mean follow-up was 5.1 +/- 3.8 years and was 100% complete.

RESULTS

There were two operative and six late deaths. Survival at 10 years was 92% +/- 3%. Moderate aortic insufficiency developed in 3 patients, and severe developed in 2. Freedom from moderate or severe aortic insufficiency was 94% +/- 4% at 10 years. Two patients required aortic valve replacement. Freedom from aortic valve replacement was 95% +/- 4% at 10 years. At the latest follow-up, 90% of the patients were in New York Heart Association functional class I and 10% were in class II.

CONCLUSIONS

Reimplantation of the aortic valve to treat patients with aortic root aneurysm is associated with excellent long-term survival and low rates of valve-related complications. Reimplantation of the aortic valve is a durable type of aortic valve repair.