Echocardiographic Localization of Left Ventricular Free Wall Rupture After Minimally Invasive Mitral Valve Replacement

EFT VENTRICULAR RUPTURE is a rare but severe complication of mitral valve replacement associated with a mortality that exceeds 75%. 1 The choice of initial intervention depends on the site of left ventricular rupture. 1,2 However, the precise determination of the site and extent of the injury can be extremely difficult in the setting of ongoing bleeding and limited ability to expose the posterior left ventricular wall. Transesophageal echocardiography (TEE), which has become a standard intraoperative diagnostic tool in treatment of patients with mitral valve disease, can offer vital information regarding the site of the ventricular rupture. A patient is described in whom successful repair of left ventricular free wall rupture was performed after minimally invasive valve replacement. CASE PRESENTATION A 75-year-old woman with severe symptomatic mitral valve regurgitation was referred for mitral valve replacement. The patient described symptoms of dry cough with gradual worsening of fatigue and dyspnea with minimal exertion. Preoperative transthoracic echocardiogram showed an ejection fraction of 45% with severe mitral regurgitation related to calcific disease and prolapse. Coronary angiogram showed no evidence of coronary artery disease. The patient underwent an operation through a limited 6-cm long skin incision and partial inferior sternotomy extending from the xyphoid process to the second right intercostal space. Cardiopulmonary bypass (CPB) with vacuum-assisted drainage was established by direct cannulation of the ascending aorta and percutaneous cannulations of the right internal jugular vein and right femoral vein. Mitral valve exposure was obtained through the transseptal approach, after isolation of the right atrium. The valve was found to be severely calcified in both the anterior and posterior leaflets, prohibiting repair. In addition, there were several ruptured chordae on the anterior leaflet. Extensive calcifications of both papillary muscles extending to the base of the muscles were noted. The anterior leaflet was excised, and a partly calcified posterior leaflet was preserved in its entirety. A 31-mm pericardial mitral valve (Edwards Life Sciences, Irvine, CA) was inserted using a row of 2-0 noneverted pledgeted sutures. The total aortic cross-clamp time was 75 minutes. The patient was weaned off CPB without difficulty. Suddenly, just before sternal closure, a large amount of blood filled the pericardium. The patient was emergently recannulated after conversion to a full sternotomy. The TEE identified a large linear tear in the left ventricular free wall, several centimeters distal to the atrioventricular groove (Fig 1). The defect was repaired by suturing a patch of bovine pericardium to the epicardial surface with 3-0 pledgeted Prolene sutures. The patient was subsequently weaned from CPB successfully. The sternum was closed in a delayed fashion 2 days later. The patient recovered completely and was discharged to a rehabilitation facility on the 9th postoperative day. The patient presented again 3 months later with symptoms of congestive heart failure. Transthoracic echocardiogram showed a large (4.5 4 cm) pseudoaneurysm of the left ventricle with a disruption of the lateral left ventricular wall approximately 3 cm distal to the mitral annulus. The decision was made to repair the pseudoaneurysm via a left thoracotomy, through the sixth intercostal space, using femoro-femoral CPB with moderate hypothermia (20°C). After achieving ventricular fibrillation, the pseudoaneurysm was entered just anterior to the phrenic nerve. A large amount of blood clot was evacuated. A large myocardial defect (4 6 cm) was identified at the base of the anterolateral papillary muscle, away from the struts of the mitral bioprosthesis. The pseudoaneurysm was repaired using a 2-layered Dacron patch and a row of pledgeted 2-0 Ethibond (Ethicon Somerville, NJ) sutures. The patient was weaned from CPB with no difficulties. Postoperative echocardiogram showed an ejection fraction of 25%, good function of the mitral valve prosthesis, and no residual pseudoaneurysm. DISCUSSION Less-invasive approaches in surgical treatment of mitral valve disease are associated with faster recovery, lower hospital cost, and higher patient satisfaction. 3 Although advances in techniques of minimally invasive mitral valve surgery have established this approach as the safe and less-invasive alternative to standard techniques, they have not been able to eliminate the occurrence of complications traditionally associated with mitral valve replacement. This report describes the only case of ventricular rupture in more than 400 minimally invasive mitral valve operations (360 mitral valve repairs and 49 mitral valve replacements) performed at the Brigham and Women’s Hospital since 1996. Risk factors for development of ventricular rupture can be divided into patient-related factors, constitutional factors, and factors related to surgical technique. The patient presented in this report had most of the constitutional risk factors for left ventricular rupture after mitral valve replacement, including advanced age, female sex, small body size, and calcified mitral annulus. The most common causes of left ventricular rupture related to surgical techniques include extensive decalcification of the mitral annulus and insertion of an oversized prosthesis, which can lead to a tear of the atrioventricular sulcus (type I lesion). Resection of the posterior leaflet and chordal attachments can result in midventricular rupture (type III) through “untethering” of the left ventricle. 4 In the present case, the authors had preserved the entire posterior mitral leaflet and