Use of Novel Blunt Dissection Technique for Surgical Unroofing in Myocardial Bridging Patients

Abstract

Background. Myocardial bridging (MB) is a congenital anomaly involving the myocardial tissue encasement of a segment of the coronary artery. The purpose of the present study was to assess safety and efficacy of two surgical methods used for treating MB patients at our institute. Methods. Off-pump MB unroofing was performed in 45 adult patients between January 2016 and December 2021 by traditional surgical unroofing techniques (conventional group, n = 26) and blunt dissection techniques (blunt dissection group, n = 19). We retrospectively reviewed our patients by examining the baseline clinical characteristics, risk factors, medications, and diagnostic data for coronary artery disease. The Seattle Angina Questionnaire (SAQ) was used to assess angina symptoms both preoperatively and 6 months postsurgery. Results. No significant difference in preoperative clinical characteristics was observed between the two groups. The blunt dissection group had shorter unroofed period (14.69 vs. 18.91 mins, $P=0.001$ ), less ventilator time (16.26 vs. 24.62 hours, $P<0.001$ ), and a shorter hospital stay (8.74 vs. 12.89 days, $P<0.001$ ). Although both traditional and blunt dissection techniques significantly improved postoperative SAQ scores including physical limitation due to angina, anginal stability, anginal frequency, treatment satisfaction, and quality of life ( $P<0.001$ ), no significant difference was observed between the traditional and blunt dissection techniques for SAQ. No cases of left anterior descending (LAD) injury in the blunt dissection group were observed although seven patients in the conventional group had LAD injuries. Conclusions. In our single-center experience of MB unroofing, the blunt dissection technique is a safe, effective technique that significantly reduces surgical and ventilator time and hospital stay. MB patients with severe angina who underwent the blunt dissection for surgical unroofing experienced significant improvements in anginal symptoms and quality of life six months after the surgery.