A Surgical Method for Subvalvular Structure Intervention Through a Transaortic Approach in Normal Bama Pigs

Subvalvular structure abnormalities leading to left ventricular outflow tract (LVOT) alterations and myocardial hypertrophy are characteristic anatomical features of structural heart diseases such as hypertrophic cardiomyopathy (HCM). This study establishes a surgical method for aortic subvalvular structure intervention through a transaortic approach in normal Bama pigs. Animals were obtained from a certified experimental pig supplier in Beijing (Licence No. SCXK (Jing) 2018-0008).This method was validated in three healthy female Bama miniature pigs aged approximately 33-35 weeks, weighing 30-35 kg at the time of surgery. The procedure involves a median sternotomy and an anterior aortic wall incision, performed under cardiopulmonary bypass (CPB) support, hypothermic cardiac arrest, and direct visualization of the LVOT and subvalvular regions. Targeted tissue traction, localization, and cutting are utilized to remodel the subvalvular structure. The complete surgical process includes anesthesia induction, placement of a central venous catheter and urinary catheter, surgical site disinfection and draping, median sternotomy, pericardial incision, and cardiac mobilization. CPB is established through left atrial drainage and retrograde coronary sinus perfusion. Following an anterior aortic wall incision, the left ventricle is accessed across the aortic valve, and subvalvular tissue intervention is performed under cardiac arrest. The procedure concludes with aortic closure, cardiac resumption of beating, CPB withdrawal, and thoracic closure. Throughout the procedure, hemodynamic stability was maintained, and the animal remained in good condition without intraoperative mortality. After surgery, the cut surfaces were smooth, and the surrounding structures remained intact. This method demonstrates high reproducibility and procedural controllability, providing a stable surgical intervention model for studying subvalvular structure intervention. It also offers a technical platform for conducting histological analysis, surgical validation, and intervention strategy evaluation.