(A) Preoperative echocardiography demonstration subvalvular stenosis and sufficient annulus size; (B) intraoperative aspect of the DAH before explantation (explantation performed after completion of the patients enrolment in the study); (C) postoperative echocardiography after implantation of a 17-mm DAH and resection of subvalvular stenosis; (D) HE staining of the non-coronary cusp; (E) Pentachrom staining of the non-coronary cusp; (F) Van Kossa staining of the non-coronary cusp; (G) HE staining of the non-coronary sinus; (H) Pentachrom staining of the non-coronary sinus; (I) Van Kossa staining of the non-coronary sinus.