Transcatheter aortic valve-in-ring implantation: feasibility in an acute, preclinical, pilot trial

Mid-term outcomes of aortic valve repair using an anatomically shaped internal annuloplasty ring

OBJECTIVES

The Hemispherical Aortic Annuloplasty Reconstructive Technology (HAART) ring is a rigid, internal and geometric device. The objective of this article is to assess the mid-term outcomes of aortic valve repair (AVr) using this prosthesis.

METHODS

A prospectively maintained database was used to obtain outcomes for adult patients undergoing AVr using the HAART ring between September 2017 and June 2023. All aortic patients at our institution undergo life-long surveillance with regular assessment and valve imaging.

RESULTS

Seventy-one patients underwent AVr using the HAART device: 53 had a trileaflet valve and 18 a bicuspid valve. The median age was 54 years, and most were male (79%). Many required concomitant intervention: 46% had a root procedure and 77% an arch repair. There were no in-hospital deaths, and the median postoperative stay was 5 days. At a mean follow-up of 3.9 (±1.1) years, freedom from reoperation was 94%. Late imaging demonstrated: zero trace (25%), 1+ (54%), 2+ (15%) and 4+ (6%) aortic insufficiency (AI). Eleven patients have ≥moderate AI under surveillance, all of whom have a trileaflet valve (21% of trileaflet patients). Four patients required reoperation: 3 for ring dehiscence and 1 for endocarditis.

CONCLUSIONS

Although early results using the HAART device are encouraging, mid-term results raise concern as 21% of trileaflet patients developed recurrent ≥moderate AI by 4 years post-repair. We experienced 3 incidences of ring dehiscence requiring reoperation. Based on this, we recommend caution using the sub-annular approach for stabilization in patients with trileaflet aortic valves. Long-term results are needed to assess outcomes against established techniques.

Conformational changes during in vitro balloon fracture of internal aortic annuloplasty ring

OBJECTIVE

HAART 300 300 (BioStable Science and Engineering, Inc) aortic annuloplasty rings restore physiologic annular geometry during aortic valve repair. Transcatheter valve-in-ring implantation is appealing for recurrent valve dysfunction but may necessitate balloon fracture of downsized annuloplasty rings. We characterized the feasibility of ring fracture and changes in ring geometry preceding fracture.

METHODS

The 19-mm, 21-mm, and 23-mm HAART 300 annuloplasty rings were obtained, and 23-mm, 24-mm, 25-mm, and 26-mm valvuloplasty balloons were obtained. Under continuous fluoroscopy and video recording, a 23-mm balloon was inflated within a 19-mm ring at 1 atm/s until ring fracture or balloon failure occurred. If balloon failure occurred, experiments were sequentially repeated with 1-mm upsized balloons until ring fracture occurred or no larger-sized balloons were available.

RESULTS

Upon balloon inflation, all rings exhibited an irreversible conformational change from an elliptical, annular geometry to a circular shape with ring posts flaring outward. A 23-mm balloon burst at 21 atm without fracturing the 19-mm ring. The 24-mm balloon fractured the 19-mm ring at 15 atm. Likewise, a 24-mm balloon ruptured at 18 atm without fracturing the 21-mm annuloplasty ring. A 25-mm balloon fractured the 21-mm ring at 18 atm. Finally, a 26-mm balloon burst at 20 atm without fracturing a 23-mm annuloplasty ring, but it did elicit the confirmational changes described. All fractures occurred along the upslope of a ring post. The exposed metal frame was visible after the 21-mm ring fracture.

CONCLUSIONS

Fracture of HAART 300 aortic annuloplasty rings is possible with an oversized, high-pressure balloon. However, the geometrical changes in the ring and subsequent rupture of its fabric covering may be obstacles to safe, in vivo ring fracture.

Comparison of a new bioprosthetic mitral valve to other commercially available devices under controlled conditions in a porcine model

Background/Aim

To evaluate three mitral bioprostheses (of comparable measured internal diameters) under controlled, stable, hemodynamic and surgical conditions by bench, echocardiographic, computerized tomography and autopsy comparisons pre‐ and postvalve implantation.

Methods

Fifteen similar‐sized Yorkshire pigs underwent preprocedural computerized tomography anatomic screening. Of these, 12 had consistent anatomic features and underwent implantation of a mitral bioprosthesis via thoracotomy on cardiopulmonary bypass (CPB). Four valves from each of three manufacturers were implanted in randomized fashion: 27‐mm Epic, 27‐mm Mosaic, and 25‐mm Mitris bioprostheses. After CPB, epicardial echocardiographic studies were performed to assess hemodynamic function and define any paravalvular leaks, followed by postoperative gated contrast computerized tomography. After euthanasia, animals underwent necropsy for anatomic evaluation.

Results

All 12 animals had successful valve implantation with no study deaths. Postoperative echocardiographic trans‐valve gradients varied among bioprosthesis manufacturers. The 25‐mm Mitris (5.1 ± 2.7)/(2.6 ± 1.3 torr) had the lowest peak/mean gradient and the 27‐mm Epic bioprosthesis had the highest (9.2 ± 3.7)/(4.6 ± 1.9 torr). Surgical valve opening area (SOA) varied with the 25‐mm Mitris having the largest SOA (2.4 ± 0.15 cm²) followed by the 27‐mm Mosaic (2.04 ± 0.23 cm²) and the 27‐mm Epic (1.8 ± 0.27 cm²) valve. Bench device orthogonal internal diameter measurements did not match manufacturer device size labeling: 25‐mm Mitris (23 × 23 mm), 27‐mm Mosaic (23 × 22 mm), 27‐mm Epic (21 × 21 mm).

Conclusions

Current advertisement/packaging of commercial surgical mitral valves is not uniform. This study demonstrates marked variations in hemodynamics, valve opening area and anatomic dimensions between similar sized mitral bioprostheses. These data suggest a critical need for standardization and close scientific evaluation of surgical mitral bioprostheses to ensure optimal clinical outcomes.

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.

Balloon Transcatheter Aortic Valve Replacement After Aortic Valve Repair With HAART 300 Device

The HAART 300 (BioStable Science and Engineering, Austin, TX) is a rigid, elliptical device introduced to facilitate aortic valve repair providing annular stabilization in the setting of aortic regurgitation. Percutaneous strategies have been described for patients with dysfunctional biological prostheses or recurrence insufficiency after mitral ring annuloplasty. This report shows the feasibility of aortic valve-in-ring transcatheter aortic valve replacement (TAVR). The sufficient ring stability to support the implanted TAVR-prosthesis and the fact that the elliptical shape of the HAART-ring did not result in a problem concerning paravalvular leakage were important for the success of this procedure.

Valve-in-Ring Transcatheter Aortic Valve Replacement After Left Ventricular Assist Device Therapy

Aortic regurgitation after left ventricular assist device (LVAD) implantation is a well-described problem that decreases the clinical effectiveness of LVAD therapy and may eventually prompt consideration of aortic valve replacement once the regurgitation becomes severe. Transcatheter aortic valve replacement is an attractive, less invasive option compared with surgical aortic valve replacement in these patients. We report a valve-in-ring transcatheter aortic valve replacement for a patient with severe aortic regurgitation associated with LVAD destination therapy. Our case demonstrates that this approach is feasible in humans and can yield excellent clinical results.