The analysis to early outcomes of thoracoscopic transmitral myectomy for patients with hypertrophic obstructive cardiomyopathy / 中华胸心血管外科杂志

ABSTRACT

Objective:To explore the early surgical outcomes of Thoracoscopic Transmitral Myectomy(TTM) on patients with hypertrophic obstructive cardiomyopathy(HOCM).Methods:Preoperative echocardiography and cardiac magnetic resonance were used to evaluate the patient's hypertrophy extent, mitral valve morphology and function. Myocardial resection was performed via the trans-mitral approach under total thoracoscopy, and the surgical methods and early results were analyzed.Results:From April 2019 to October 2019, a total of 15 cases of TTM were performed by a single surgeon in our ward. Preoperative imaging evaluation revealed that 6 patients(40.0%) had predominantly hypertrophic basal septum while another 9 patients(60.0%) had concomitant midventricular septal hypertrophy. Two(13.3%) patients were interrogated ruptured posterior mitral chord by preoperative echocardiogram. After myocardial resection, the mitral valve was treated as follows 11 patients(73.3%) underwent anterior leaflet enlargement, and 3(20.0%) were directly reattached to mitral valve annulus, and 1(6.7%) underwent bioprosthetic mitral replacement. There was no case of perioperative death, ventricular septal perforation, residual left ventricular outflow tract obstruction and complete atrioventricular block. Median aortic crossclamp time, cardiopulmonary bypass time, postoperative ventilator use time, ICU stay time, and postoperative hospital stay were 129.0min(116.0, 147.0), 184.0 min(158.0, 227.0), 22.0 h(9.0, 26.0), 3 days(2, 7) and 9 days(7, 14) respectively. No patient lost to follow up, the median follow-up time was 4 months(2, 5). One patient(6.7%) underwent mitral angioplasty three months after surgery due to a tear in the A3 area; the ventricular septal thickness and left ventricular outflow tract pressure decreased significantly(preoperative vs follow-up), and were(19.3±3.3)mm vs. (8.9±4.4) mm( P=0.001), (90.8±23.2)mmHg vs. (8.9±4.4) mmHg(1 mmHg = 0.133kPa)( P<0.001) respectively; no residual SAM was observed during follow-up. Patients with moderate-to severe mitral regurgitation were decreased from 12(80.0%) before surgery to 1(6.7%) during follow up( P<0.001). Conclusion:TTM is a safe and effective procedure for HOCM patients with appropriate surgical indications, providing better exposure to septum from basal to apical area, eliminating left ventricular outflow tract obstruction and SAM-related mitral regurgitation. The anterior mitral valve leaflet should be carefully treated during surgery to reduce the occurrence of residual mitral regurgitation resulted in inappropriate selection of patch size and suturing technique.