Technique for aortic valve annuloplasty using an intra-annular “hemispherical” frame

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.

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

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

A modern approach to aortic valve insufficiency: Aortic root restoration via HAART 300 internal annuloplasty ring

BACKGROUND AND AIM OF THE STUDY

HAART 300 is an internal geometric annuloplasty ring. The safety and efficacy of this novel device in aortic valve (AV) repair in a single referral center are reported.

METHODS

Twenty patients with trileaflet AV insufficiency with ascending aorta and/or aortic root enlargement were included. Subannular implantation was performed to correct annular dilatation, whereas concomitant leaflet repair was performed whenever required. All but two patients also received ascending aorta replacement, whereas selective sinus replacement was performed in all but five patients.

RESULTS

Follow-up was for a maximum of 3.8 years and a mean of 2.2 years. Mean age was 54.2 years old. Moderate to severe preoperative AV insufficiency was noted in 75% of patients, whereas 70% of them had an ascending aorta over 45 mm. One patient was lost from follow-up. Overall mortality as well as major complication rates were zero. Early postoperatively, no more than mild AV regurgitation was detected, whereas only one patient appeared with moderate AV regurgitation during our 2.2-year follow-up. New York Heart Association class was also significantly lower compared to preoperative values and valve gradients remained low at last follow-up.

CONCLUSIONS

Geometric ring annuloplasty is a safe and effective valve sparing approach to deal with AV insufficiency contributing to overall root reconstruction. Short-term results are excellent rendering this easily reproducible and versatile method very attractive.

Aortic valve repair with a newly approved geometric annuloplasty ring in patients undergoing proximal aortic repair: early results from a single-centre experience

OBJECTIVES

Aortic insufficiency (AI) is common in patients with proximal aortic disease, but limited options exist to facilitate aortic valve repair (AVr) in this population. This study reports 'real-world' early results of AVr using newly FDA-approved trileaflet and bicuspid geometric annuloplasty rings for patients with AI undergoing proximal aortic repair (PAR) in a single referral centre.

METHODS

All patients undergoing AVr with a rigid internal geometric annuloplasty ring (n = 47) in conjunction with PAR (ascending +/- root +/- arch) were included. Thirty-six patients underwent AVr with a trileaflet ring, and 11 patients underwent AVr with a bicuspid ring. The rings were implanted in the subannular position, and concomitant leaflet repair was performed if required for cusp prolapse identified after ring placement.

RESULTS

The median age was 58 years [interquartile range (IQR) 46-70]. PAR included supracoronary ascending replacement in 26 (55%) patients and remodelling valve-sparing root replacement with selective sinus replacement in 20 (42%) patients. Arch replacement was performed in 38 (81%) patients, including hemi-arch in 34 patients and total arch in 4 patients. There was no 30-day/in-hospital mortality. Preoperative AI was 3-4+ in 37 (79%) patients. Forty-one (87%) patients had zero-trace AI on post-repair transoesophageal echocardiography, and 6 patients had 1+ AI. The median early post-repair mean gradient was 13 mmHg (IQR 5-20). Follow-up imaging was available in 32 (68%) patients at a median of 11 months (IQR 10-13) postsurgery. AI was ≤1+ in 97% of patients with 2+ AI in 1 patient. All patients were alive and free from aortic valve reintervention at last follow-up.

CONCLUSIONS

Early results with geometric rigid internal ring annuloplasty for AVr in patients undergoing PAR appear promising and allow a standardized approach to repair with annular diameter reduction and cusp plication when needed. Longer-term follow-up will be required to ensure the durability of the procedure.

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.

Initial Application of a Bicuspid Aortic Annuloplasty Ring in Pediatric Cardiac Surgery

Aortic stenosis and aortic insufficiency (AI) are common valvular conditions that may necessitate repair or replacement of the aortic valve. Aortic valve replacement is associated with higher long-term complications and thus, a consistent, reliable method of repair is needed. This is especially true in the pediatric population where lifelong anticoagulation and development of recurrent aortic stenosisor aortic insufficiency are especially problematic. The Hemispherical Aortic Annuloplasty Reconstruction Technology ring has been developed and used for annular stabilization in adults with success, though its efficacy in the pediatric population has yet to be demonstrated. Herein, we discuss the use of a geometric ring in aortic valve repair for the pediatric patient.

Leaflet reconstructive techniques for aortic valve repair

BACKGROUND

Refining leaflet reconstruction has become a primary issue in aortic valve repair. This descriptive analysis reviews leaflet pathology, repair techniques, and early results in a prospective regulatory trial of aortic valve repair.

METHODS

Sixty-five patients underwent valve repair for predominant moderate to severe aortic insufficiency (AI). The mean age was 63 ± 13 years, and 69% of the patients were male. Ascending aortic/root replacement was required in 62%. As a first step, ring annuloplasty was performed, and then leaflet repair included leaflet plication for prolapse, nodular unfolding, double pericardial patching of commissural defects or holes, complete pericardial leaflet replacement, leaflet extension, and Gore-Tex reinforcement. Leaflet techniques and causes of adverse outcomes were evaluated.

RESULTS

The follow-up time was 2-years maximal and 0.9 years mean, with a survival of 97%. Eighty percent of patients required repair of leaflet defects: leaflet prolapse (52/65-80%), ruptured commissures (6/65-9%), leaflet holes (4/65-6%), and nodular retraction (6/65-9%). The average preoperative AI grade of 2.9 ± 0.8 fell to 0.7 ± 0.7 (p < 0.0001). Three patients (4.6%) required interval valve replacement because of (1) suture untying, (2) iatrogenic leaflet tear, or (3) diphtheroid endocarditis. Five other patients experienced grade 2 or grade 3 AI: probable suture untying in 1 patient, ineffective leaflet extensions in 2 patients, and unsuccessful Gore-Tex reinforcements in 2 patients. Two patients with single pericardial leaflet replacements and all those with double pericardial reconstructions did well.

CONCLUSIONS

Leaflet defects are common in patients with moderate to severe AI. Leaflet plication, nodular unfolding, and double pericardial patching performed well. Gore-Tex and leaflet extension seemed less satisfactory. Standardization and experience with leaflet reconstruction will be important for optimizing the outcomes of aortic valve repair.

Design Characteristics of a Three-Dimensional Geometric Aortic Valve Annuloplasty Ring

Objective

A full geometric annuloplasty ring could facilitate aortic valve repair. The purpose of this report was to document the design of such a ring using mathematical analyses of normal human aortic valve computed tomographic angiograms.

Methods

One-millimeter axial slices of high-resolution computed tomographic angiograms from 11 normal aortic roots were used to generate high-density x, y, and z coordinates of valve structures in Mathematica. Three-dimensional least squares regression analyses of leaflet-sinus coordinates were used to assess geometry of aortic valve and root structures.

Results

Normal valve geometry could be represented as three leaflet-sinus general ellipsoids nested within an elliptical aortic root. Minor-major diameter ratio of the valve base was 0.60 ± 0.07, and elliptical geometry extended vertically up the commissures. By contrast, leaflet-sinus horizontal circumferences were fairly circular (diameter ratios, 0.82–0.87), and the left coronary/noncoronary commissural post was located at the posterior base minor diameter-circumference junction, with the center of the right coronary leaflet opposite. Post location on the circumference was symmetrical, with a deviation of only ±2% to ±3% from 33.3% symmetry. Commissural posts flared outward by 5 to 10 degrees, and leaflet areas were statistically equivalent ( P > 0.10). From end diastole to midsystole, the aortic root became less elliptical (diameter ratio increased by 0.15), but root area expanded minimally (less than +5%). A one-piece rigid annuloplasty ring was designed with 2:3 base ellipticality, three 10-degree outwardly flaring symmetrical posts, and post height = base circumference/2π.

Conclusions

A three-dimensional aortic annuloplasty ring was designed that could prove useful for enhancing applicability and stability of aortic valve repair.

In vivo testing of an intra-annular aortic valve annuloplasty ring in a chronic calf model

OBJECTIVE

To increase applicability and stability of aortic valve repair, a three-dimensional aortic annuloplasty ring has been developed for intra-annular placement. The goal of this study was to test the safety of this device with in vivo implantation in the calf model.

METHODS

In 10 chronic calves, the HAART annuloplasty ring was sutured to the aortic valve annulus using cardiopulmonary bypass. The animals were recovered and followed for 1-2 months. Serial echocardiography was used to evaluate valve competence, and contrast aortograms and CT angiograms were obtained in selected animals. After completion of follow-up, each animal was euthanized, and aortic endoscopy was performed under water distension in five. Full autopsies with histologic examinations were performed.

RESULTS

All animals survived surgery. Two were euthanized in the first week for complications, and the remaining eight calves were followed uneventfully for the 1-2 months. Serial echocardiography showed completely competent valves in all but one animal, in which the ring was intentionally up-sized to test the sizing strategy. Contrast aortographic and CT angiographic findings were similar to the echocardiograms. Postmortem examination showed proper seating of all rings with endothelialization at 1-2 months. All valves demonstrated good leaflet coaptation and no abnormalities.

CONCLUSIONS

In vivo testing of a three-dimensional aortic annuloplasty ring in a chronic calf model proved to be very successful and safe. Using the sizing and implant strategies developed, human trials seem indicated.

Techniques of Aortic Valve Repair

Similar to mitral repair, newer methods of aortic valve reconstruction are achieving excellent outcomes with an 85% to 90% freedom from valve-related complications at 10 years. The goal of this review is to illustrate these newer and more stable techniques of aortic valve repair. Most patients with aortic insufficiency from either trileaflet or bicuspid aortic valves are candidates for repair, in addition to selected patients with mixed aortic stenosis/insufficiency and aortic root aneurysms. Initially, aggressive commissural annuloplasty is performed to reduce measured valve diameter to 19 to 21 mm. Leaflet prolapse is corrected with plication stitches placed in the free edge of each leaflet adjacent to the Nodulus Arantius. In this regard, the leaflet free edge functions as the chorda tendinea of the aortic valve, and shortening with plication stitches raises the leaflet to a proper “effective height.” Leaflet defects are augmented with gluteraldehyde-fixed autologous pericardium, and mild-to-moderate strategically placed spicules of calcium are removed with the cavitron ultrasonic surgical aspirator. Using these methods, most insufficient aortic valves, and many with mixed lesions, can be satisfactorily repaired. Six cases are illustrated in this review, spanning the spectrum of pathologies from annular dilatation without leaflet defects, to standard congenital bicuspid valve with prolapse, to trileaflet prolapse, to unusual bicuspid pathology with calcification, to a moderately calcified trileaflet valve with mixed lesions, and to aortic root aneurysms with severe aortic insufficiency. All valves were repaired using the techniques described above with trivial residual leak and minimal gradients. All repairs have been followed with yearly echocardiography, and valve reconstruction with these methods is now quite stable with excellent late outcomes. Most insufficient aortic valves now can undergo stable repair with minimal late valve-related complications. Greater application of aortic valve repair seems indicated.