Facing the small aortic root in aortic valve replacement: Enlarge or not enlarge?

In patients with severe aortic stenosis, aortic valvereplacement (AVR) should aim to implant a prosthesis ofadequate size to effectively eliminate left ventricularobstruction and avoid the risk of patient–prosthesismismatch (PPM). PPM has been demonstrated to be associ-ated with increased mortality, decreased exercise tolerance,and reduced left ventricular mass regression after AVR foraortic stenosis.1The important paper by Tam and colleagues2in theOctober 2020 issue of theJournalpresents the results of amulticenter study analyzing 2 cohorts of patients, comparedby propensity score matching, with or without aortic rootenlargement (ARE) at time of AVR. They confirmed thatARE did not influence neither early mortality, despitelonger operation times, nor survival up to 8 years, whencompared with AVR alone. However, in their study thereis no mention of the techniques used for ARE, which mayhave a different impact on the entity of annular enlarge-ment,3on the real increase of prosthetic sizes, and whetherPPM was effectively eliminated or minimized.We have always been interested in the issue of PPMfollowing AVR, and in a recent study we have shown, inagreement with Tam and colleagues,2that ARE is a safeand effective technique that does not adversely affect oper-ative mortality4; moreover, our clinical, echocardiographic,and angio–computed tomographic follow-up indicates that,when a pericardial patch is used for ARE, this procedure isextremely stable, with no aneurysm formation up to 18 yearsand effectively addressing the problem of PPM. In must alsobe emphasized that, in their population, Tam andcolleagues2report a high prevalence of tissue valves em-ployed for AVR. In this respect, the need to avoid PPM ap-pears even more relevant considering that PPM mayaccelerate structural deterioration of biological prostheses,either porcine or pericardial, influencing their long-termdurability.5There is currently enough evidence that ARE representsan important adjunct to the surgical armamentarium andthat it should receive more widespread acceptance; on theother hand, use of small-sized bioprostheses for AVRshould be discouraged, also in view of possible futurevalve-in-valve procedures.The experience by Tam and colleagues2is clearly in favorof ARE during AVR. Despite the increasing use of new bio-prosthetic models, such as the rapid deployment or suture-less devices, we feel that ARE should be still taught to theyoung generations so that they can grow eliminating at leastone of the many Hamletic doubts with which cardiac sur-geons are daily faced