Sutureless aortic valve replacement: the importance of sizing

Dear Editor,

We read with interest the article by Dr Szecel et al. [1], that confirms the paramount importance of a correct sizing during sutureless aortic valve implantation. In this study, the authors compared patients receiving a sutureless valve before and after the introduction of a new (but still obturator based) sizing strategy, aiming to avoid excessive oversizing. The new sizing strategy was associated with improved results. In particular, it was associated with reduced transprosthetic gradients at discharge, and with a reduced incidence of intraprosthetic aortic regurgitation and pacemaker implantation. However, given the absence of an objective measurement of the aortic annulus, the degree of oversizing was only estimated on the basis of the patients's BSA.

We have previously reported a strong relationship between an excessive Perceval valve oversizing and the development of increased postoperative transprosthetic gradients: in a series of 151 patients, we found that an oversizing ≥30% (as objectively measured at CT) was associated with a 16-fold increase of the risk of being discharged with a mean transprosthetic gradient of >20 mmHg [2]. We also described a strong association between gross oversizing and valve thrombosis [3]. Consequentially, we proposed to adopt the cardiac CT-derived virtual basal ring measurement as a mean to standardize the sizing of sutureless valves and suggested to use an approach similar to what is done for transcatheter aortic valve replacement to achieve optimal sizing of the Perceval aortic bioprostheses, possibly helping to prevent postoperative pacemaker implantation, paravalvular leakage and endocarditis [4].

We have adopted this strategy in several patients, with good and consistent results. Recently, we have compared 15 patients receiving a prosthesis measured at CT with 11 patients that had a baseline CT but underwent conventional sizing. Interestingly, the degree of oversizing was significantly reduced in the CT-based sizing group (10,4% vs 26%, P < 0.05, abstract presented at the 2023 HVS meeting). In the 2 patients with discordant measures, the CT-based sizing was preferred: this led to the reduction of the oversizing from 28.6% to 8.7% and from 30.7% to 10.2%, respectively. Despite the new sizing recommendations provided by the company, in these 2 border-line patients, the obturator-based sizing would have probably resulted in excessive oversizing.

Dr Scezel and co-workers should be congratulated for this interesting paper, stressing again the importance of correct sutureless valve sizing. However, we believe that CT-based sizing could contribute to further improve the outcomes of sutureless AVR, especially in patients with border-line annuli—the ones that are truly at risk of excessive oversizing.