( 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.