HAART—anatomical internal annuloplasty technology still in evolution

The - Hemispheric Aortic Annuloplasty Remodelling Ring (HAART) , is an interesting option for aortic valve repair, providing annulus reduction and, annulus and root stabilization. The internal geometric ring provides full three-dimensional annular stability while minimizing the dissection of the aortic root, pulmonary artery and right ventricle and avoids reimplanting the coronaries. The interesting comments from the Duke group reported technical issues related to its use [1]. They looked at medium-term follow-up of 71 patients and reported 4 redooperations. Some arguments have been raised on potential disadvantages related to the risk of dehiscence and simultaneous leaflet perforation, observed in 3 patients, all of them presented with trileaflet configuration affecting noncoronary sinus and leaflet. The last redooperation was caused by endocarditis Interestingly, there were no failures in bicuspid repair, probably related to 180° symmetry and as a result equal distribution of forces. This observations corroborate with good clinical results of BAV repair across whole spectrum of phenotypes [2, 3]. Risk of dehiscence of HAART aortic annuloplasty is estimated of 1% and is comparable with mitral annuloplasty ring as a result of similar radial and suture forces, therefore there is no theoretical base for higher dehiscence rate [3–5]. These forces confirmed to be couteracted by looping ring sutures as shown by mathematical simulations [6]. While there have been really rare such reports in the short to mid-term data, the risk can be reduced intraoperatively in high-risk situations due to discrepancy between annulus and ring sizes. This goal may be achieved by combining internal and external annuloplasty. This modification has been described in my tutorial on MMCTS [2]. Reducing the pledgets on the aortic side may ameliorate fibrosis which might affect the leaflet motion as well as eliminate the risk of leaflet perforation. The external annuloplasty provides a secondary stabilization of the easily accessed fibrous portion of the annulus using the externalization of sutures for the internal annuloplasty device, which minimizes the sutures above the leaflets, what ameliorates risk of endocarditis. To further eliminate potential fibrosis and endocarditis, Goretex looping sutures and pledgets can mitigate progressive fibrosis due to unique anti-inflammatory characteristics.