Totally endoscopic minimally invasive mitral valvuloplasty with a beating heart for treatment of papillary muscle rupture.

Central MessageTotally endoscopic minimally invasive mitral valvuloplasty with beating heart in the papillary muscle rupture accompanied with severe heart failure is effective and reliable.See Commentary on page XXX. Totally endoscopic minimally invasive mitral valvuloplasty with beating heart in the papillary muscle rupture accompanied with severe heart failure is effective and reliable. See Commentary on page XXX. A 64-year-old man who presented with papillary muscle rupture (PMR) after acute myocardial infarction and cardiogenic shock was emergency transferred to our institution with the support of intra-aortic balloon pump (IABP) and extracorporeal membrane oxygenation (ECMO). The patient had undergone percutaneous coronary intervention 3 days earlier for acute right coronary artery occlusion. Electrocardiogram on admission revealed acute inferior myocardial infarction. Chest radiograph revealed acute pulmonary edema (Figure 1, A). Echocardiography demonstrated severe mitral regurgitation with posterior leaflet flail caused by PMR (Figure 1, B and C). Besides, the patient had acute liver injury and acute kidney injury requiring dialysis. Society of Thoracic Surgeons score predicted the risk of operative mortality was high, at 39.795%. Emergency totally endoscopic minimally invasive mitral valvuloplasty (MVP) on beating heart was performed (Video 1). The patient was intubated with a single-lumen endotracheal tube. Normothemic cardiopulmonary bypass was established via the femoral artery and vein while ECMO maintained self-circulation. A limited right anterolateral thoracotomy was then performed through the fourth and fifth intercostal space and the thoracic cavity was insufflated with carbon dioxide to reduce intracardiac air. Intraoperatively, mitral valvuloplasty was performed via ruptured papillary muscle heads resection (Figure 2, A), artificial chordae tendinae implantation (Figure 2, B), commisuroplasty between A3 and P3 (Figure 2, C), and annuloplasty with a 28-mm Carpentier-Edwards Physio II semirigid complete ring (Figure 2, D). Keeping the mitral valve open until the left atrium closes could help empty the air in the left ventricle to avoid potential risk of air embolism. Cardiopulmonary bypass was weaned off smoothly, and the cannulations of the femoral artery and vein were reconnected to ECMO. Postoperative transesophageal echocardiography showed trivial mitral regurgitation (Figure 1, D). The patient recovered stably; was conscious on postoperative day 2; and was weaned from ECMO, IABP, and ventilator on postoperative day 5, 7, and 21, respectively. The patient died from sepsis caused by biliary tract infection 32 days after surgery. PMR after acute myocardial infarction is a life-threatening complication (30-day mortality up to 39.3%). It results in severe mitral valve regurgitation, often accompanied by pulmonary edema and cardiogenic shock, requiring both medical treatment and emergency surgical intervention.1Massimi G. Ronco D. De Bonis M. Kowalewski M. Formica F. Russo C.F. et al.Surgical treatment for post-infarction papillary muscle rupture: a multicentre study.Eur J Cardio Thorac Surg. 2022; 61: 469-476Crossref Scopus (11) Google Scholar Mechanical circulatory assistance, including IABP and ECMO, are often needed. MVP appears to be a viable alternative to mitral valve replacement for PMR, given that it has lower operative mortality, shorter hospital stays, and similar incidence of short-term postoperative complications.2Kilic A. Sultan I. Chu D. Wang Y. Gleason T.G. Mitral valve surgery for papillary muscle rupture: outcomes in 1342 patients from the Society of Thoracic Surgeons Database.Ann Thorac Surg. 2020; 110: 1975-1981Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar However, mitral valve replacement is still the preferred strategy for most surgeons in cases of PMR (about 80%), which maybe due to the complexity and difficulty of MVP in PMR, prolonged operation time, and controversial valve reintervention.3Hamid U.I. Aksoy R. Sardari Nia P. Mitral valve repair in papillary muscle rupture.Ann Cardiothorac Surg. 2022; 11: 281-289Crossref Scopus (3) Google Scholar Conventional cardiac arrest carried a high burden of associated potential morbidity and mortality in poor left ventricular function, especially in our case. Considering better myocardial protection, high risk of valve prosthesis thrombosis under ECMO support, and accumulated extensive experience of MVP, we finally chose to perform empty beating heart MVP via totally endoscopic minimally invasive approach. Continuous myocardial perfusion throughout the operation could alleviate myocardial damage caused by hypothermia, edema, and ischemia-reperfusion injury. The alternative to the beating heart technique is a ventricular fibrillation arrest. However, fibrillation arrest may reduce oxygen delivery to the subendocardium and thus provides suboptimal myocardial protection.4Romano M.A. Haft J.W. Pagani F.D. Bolling S.F. Beating heart surgery via right thoracotomy for reoperative mitral valve surgery: a safe and effective operative alternative.J Thorac Cardiovasc Surg. 2012; 144: 334-339Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar These were reasonable explanations for the lower postoperative morbidity and mortality in the minimally invasive beating heart group. Although excellent mitral valve exposure could be obtained through incision of the interatrial groove combined with continuous drainage, the beating heart technique more or less increases returned blood volume during the operation, and the risk of blood damage is augmented. Measures (such as esmolol) to lower heart rate and avoid excessive negative pressure would be helpful. A particular concern is air embolism; however, there is controversy whether open mitral valve surgery with a beating heart increases the risk of stroke.5Zhang H. Xu H.S. Wen B. Zhao W.Z. Liu C. Minimally invasive beating heart technique for mitral valve surgery in patients with previous sternotomy and giant left ventricle.J Cardiothorac Surg. 2020; 15: 122Crossref Scopus (3) Google Scholar Generally, the aortic valve does not open easily during diastolic or systolic periods in an empty beating heart because aortic root pressure is much higher than atmospheric pressure. Besides, the beating heart technique might reduce the risk of systemic embolism by avoiding aortic crossclamp. Carbon dioxide insufflation to displace intracardiac air, continuous drainage in the ascending aorta, and adequate head-down position may also contribute to reducing the risk of embolism. The beating heart technique was helpful to achieve excellent myocardial protection, especially in patients with poor left ventricular function. Totally endoscopic minimally invasive MVP could improve surgery outcomes of patients with PMR caused by acute myocardial infarction.